2,771 community and non-transient non-community water systems are listed for Washington in EPA SDWIS. 254 were sampled under UCMR 5; 68 of those had at least one PFAS result at or above the reporting level, and 36 had a highest single result at or above a 2024 EPA limit (PFOA or PFOS 4 ppt, or Hazard Index 1).
Washington map · Download: systems (CSV) · all results (CSV, gzip)
These are monitoring results collected under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) at entry points, where treated water enters the distribution system; they are not tap-water samples. They are not compliance determinations: compliance with EPA's 2024 PFAS limits is judged on running annual averages of compliance monitoring, required from 2029, so a single UCMR 5 result at or above a limit is not a violation. “< MRL” means the compound was not quantified at EPA's minimum reporting level; it does not mean zero.
Sampled under UCMR 5 (254)
| System | PWSID | City | Population | Highest PFOA (ppt) | Highest PFOS (ppt) | Highest HI | Highest single result |
|---|---|---|---|---|---|---|---|
| Aberdeen City Of | WA5300050 | Aberdeen | 22,867 | <MRL | <MRL | 0 | No PFAS detected |
| Airway Heights City Of | WA5300650 | Airway | 9,489 | <MRL | <MRL | 0.32 | Hazard Index below its limit |
| Alderwood Water District | WA5301300 | Lynnwood | 245,715 | <MRL | <MRL | 0 | No PFAS detected |
| Anacortes City Of | WA5302200 | Mount Vernon | 25,109 | <MRL | <MRL | 0 | No PFAS detected |
| Arlington City Of | WA5302950 | Arlington | 29,508 | <MRL | <MRL | 0.49 | Hazard Index below its limit |
| Artondale | WA5303160 | Tacoma | 5,828 | 6.3 | 153.6 | 5.595 | PFOS ≥ 3 × its limit |
| Auburn City Of | WA5303350 | Auburn | 107,655 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Bainbridge Island City Of | WA5397650 | Bainbridge Island | 13,491 | <MRL | <MRL | 0 | No PFAS detected |
| Battle Ground Water Dept City Of | WA5304700 | Battle Ground | 30,237 | <MRL | <MRL | 0 | No PFAS detected |
| Bayshore | WA5304900 | Union | 130 | <MRL | <MRL | 0 | No PFAS detected |
| Beacon Hill Water & Sewer District | WA5315650 | Kelso | 11,969 | <MRL | <MRL | 0 | No PFAS detected |
| Bellevue City Of | WA5305575 | Bellevue | 321,349 | <MRL | <MRL | 0 | No PFAS detected |
| Bellingham-Water Division City Of | WA5305600 | Bellingham | 141,127 | <MRL | <MRL | 0 | No PFAS detected |
| Benton City Water | WA5305800 | Benton City | 5,626 | <MRL | 8.7 | 1.432 | PFOS 1–3 × its limit |
| Birch Bay Water & Sewer District | WA5395904 | Birch Bay | 9,046 | <MRL | <MRL | 0 | No PFAS detected |
| Blaine City Of | WA5307300 | Blaine | 6,800 | <MRL | <MRL | 0 | No PFAS detected |
| Bonney Lake Water Department City | WA5307650 | Buckley | 43,371 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Bothell Water City Of | WA5307900 | Bothell | 33,643 | <MRL | <MRL | 0 | No PFAS detected |
| Bremerton City Of | WA5308200 | Bremerton | 72,951 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Buckley Water | WA5309000 | Buckley | 7,842 | <MRL | <MRL | 0 | No PFAS detected |
| Camas Municipal Water Sewer System | WA5310800 | Camas | 31,794 | 4.4 | 12 | 0.002 | PFOS ≥ 3 × its limit |
| Castle Rock Municipal Water | WA5311800 | Castle Rock | 4,367 | <MRL | <MRL | 0 | No PFAS detected |
| Cedar Grove Mobile Park | WA5336836 | Sequim | 40 | <MRL | <MRL | 0 | No PFAS detected |
| Cedar River Water & Sewer District | WA5341800 | Maple Valley | 28,671 | <MRL | <MRL | 0 | Other PFAS detected |
| Centralia Public Works - Water | WA5312200 | Centralia | 28,164 | <MRL | 5.8 | 0.002 | PFOS 1–3 × its limit |
| Chehalis Water Department | WA5312250 | Chehalis | 11,718 | <MRL | <MRL | 0 | No PFAS detected |
| Chelan Co Pud 1 | WA5312284 | Wenatchee | 16,190 | <MRL | <MRL | 0 | No PFAS detected |
| Chelan Water Dept City Of | WA5312300 | Chelan | 9,425 | <MRL | <MRL | 0 | No PFAS detected |
| Cheney City Of | WA5312400 | Cheney | 16,954 | <MRL | <MRL | 0 | No PFAS detected |
| Clark Public Utilities | WA5313333 | Vancouver | 153,526 | 8 | 8.4 | 0.532 | PFOS 1–3 × its limit |
| Coal Creek Utility District | WA5341750 | Newcastle | 15,989 | <MRL | <MRL | 0 | No PFAS detected |
| Colfax Water Department City Of | WA5314000 | Colfax | 3,507 | <MRL | <MRL | 0 | No PFAS detected |
| College Place Water Dept | WA5314050 | College Place | 8,147 | <MRL | <MRL | 0 | No PFAS detected |
| Columbia Valley Water District | WA5366110 | Maple Falls | 2,648 | <MRL | <MRL | 0 | No PFAS detected |
| Colville Water Department | WA5314200 | Colville | 4,945 | <MRL | <MRL | 0 | No PFAS detected |
| Connell City Of | WA5314600 | Connell | 5,150 | <MRL | <MRL | 0 | No PFAS detected |
| Consolidated Irrig Dist 19 System 1 | WA5310220 | Greenacres | 9,434 | <MRL | <MRL | 0 | No PFAS detected |
| Consolidated Irrig Dist 19 System 2 | WA5310221 | Greenacres | 21,220 | <MRL | <MRL | 0 | No PFAS detected |
| Consolidated Support Services | WA5321850 | Medical Lake | 569 | <MRL | <MRL | 0 | No PFAS detected |
| Coupeville Town Of | WA5315550 | Coupeville | 4,142 | 9.8 | <MRL | 0.383 | PFOA 1–3 × its limit |
| Covington Water District | WA5341650 | Kent | 56,172 | <MRL | 8.6 | 0.756 | PFOS 1–3 × its limit |
| Crescent Water Assn | WA5316020 | Joyce | 2,360 | <MRL | <MRL | 0 | No PFAS detected |
| Cross Valley Water District | WA5316270 | Snohomish | 24,695 | <MRL | <MRL | 0.005 | Hazard Index below its limit |
| Crystal Mountain Inc | WA5316400 | Raymond | 4,154 | <MRL | <MRL | 0 | No PFAS detected |
| Deer Park City Of | WA5318500 | Deer Park | 5,435 | <MRL | 7.5 | 0.43 | PFOS 1–3 × its limit |
| Dungeness Meadows | WA5320445 | Sequim | 488 | <MRL | <MRL | 0 | No PFAS detected |
| Dupont Water System City Of | WA5320500 | Dupont | 13,141 | <MRL | <MRL | 0 | No PFAS detected |
| Duvall City Of | WA5320750 | Duvall | 11,050 | <MRL | <MRL | 0 | No PFAS detected |
| East Spokane Water Dist 1 | WA5321650 | Spokane Valley | 4,285 | <MRL | 5.5 | 0 | PFOS 1–3 × its limit |
| East Wenatchee Water District | WA5321800 | East Wenatchee | 26,519 | <MRL | <MRL | 0 | No PFAS detected |
| Eastern Washington University | WA5321900 | Cheney | 17,108 | <MRL | <MRL | 0 | No PFAS detected |
| Eastsound Water Users Association | WA5322170 | Eastsound | 3,711 | <MRL | <MRL | 0 | No PFAS detected |
| Eatonville Water Dept | WA5322300 | Eatonville | 3,945 | <MRL | <MRL | 0 | No PFAS detected |
| Edmonds City Of | WA5322500 | Edmonds | 34,065 | <MRL | <MRL | 0 | No PFAS detected |
| Ellensburg Water Dept | WA5322950 | Ellensburg | 20,900 | <MRL | <MRL | 0 | No PFAS detected |
| Elma City Of | WA5323100 | Elma | 6,638 | <MRL | <MRL | 0 | No PFAS detected |
| Emerald Lake | WA5323294 | Shelton | 329 | <MRL | <MRL | 0 | No PFAS detected |
| Energy Dept Of/200W | WA5300100 | Richland | 6,351 | <MRL | <MRL | 0 | No PFAS detected |
| Enumclaw Water Department | WA5323600 | Enumclaw | 23,276 | <MRL | <MRL | 0 | No PFAS detected |
| Ephrata Water Department | WA5323650 | Ephrata | 8,718 | <MRL | <MRL | 0 | No PFAS detected |
| Everett Public Works Dept. City Of | WA5324050 | Everett | 215,774 | <MRL | <MRL | 0 | No PFAS detected |
| Everson City Of | WA5324200 | Everson | 3,893 | <MRL | <MRL | 0 | No PFAS detected |
| Fairchild Air Force Base | WA5324350 | Fairchild Afb | 9,544 | <MRL | 7.9 | 1.702 | PFOS 1–3 × its limit |
| Ferndale | WA5324850 | Ferndale | 19,305 | <MRL | <MRL | 0 | No PFAS detected |
| Fife Dept Of Public Works | WA5325050 | Fife | 29,091 | <MRL | <MRL | 0.502 | Hazard Index below its limit |
| Fircrest City Of | WA5325150 | Fircrest | 7,927 | <MRL | <MRL | 0.003 | Hazard Index below its limit |
| Firgrove Mutual Inc | WA5325200 | Puyallup | 36,168 | 4.4 | 8.6 | 0.003 | PFOS 1–3 × its limit |
| Forks Municipal Water Dept | WA5326000 | Forks | 3,468 | <MRL | <MRL | 0 | No PFAS detected |
| Friday Harbor Town Of | WA5326595 | Friday Harbor | 3,543 | <MRL | <MRL | 0 | No PFAS detected |
| Fruitland Mutual Water Company | WA5326800 | Puyallup | 15,313 | 4 | <MRL | 0.003 | PFOA 1–3 × its limit |
| Gig Harbor Water Dept | WA5327600 | Gig Harbor | 16,510 | <MRL | <MRL | 0 | No PFAS detected |
| Gold Bar City Of | WA5328300 | Goldbar | 2,745 | <MRL | <MRL | 0 | No PFAS detected |
| Goldendale City Of | WA5328450 | Goldendale | 4,314 | <MRL | <MRL | 0 | No PFAS detected |
| Grandview City Of | WA5328970 | Grandview | 11,010 | <MRL | <MRL | 0 | No PFAS detected |
| Granger Water Department | WA5329000 | Granger | 3,993 | <MRL | <MRL | 0 | No PFAS detected |
| Granite Falls City Of | WA5329050 | Granite Falls | 5,349 | <MRL | <MRL | 0 | No PFAS detected |
| Grays Harbor Co Water Dist 2 | WA5329250 | Montesano | 5,112 | <MRL | <MRL | 0 | No PFAS detected |
| Harrington City Of | WA5331450 | Waverly | 650 | <MRL | <MRL | 0 | No PFAS detected |
| Heights Water | WA5332300 | Vashon | 2,051 | <MRL | <MRL | 0 | No PFAS detected |
| Hi Valley View | WA5300431 | Yakima | 67 | <MRL | <MRL | 0 | No PFAS detected |
| Highline Water District | WA5340650 | Kent | 100,170 | <MRL | <MRL | 0 | No PFAS detected |
| Hoquiam Water Department | WA5334350 | Hoquiam | 11,456 | <MRL | <MRL | 0 | No PFAS detected |
| Horizons West | WA5334375 | Tacoma | 3,454 | <MRL | <MRL | 0 | Other PFAS detected |
| Irvin Water District #6 | WA5336050 | Spokane | 4,150 | <MRL | <MRL | 0 | Other PFAS detected |
| Issaquah Water System | WA5336350 | Issaquah | 43,584 | <MRL | <MRL | 0 | No PFAS detected |
| Jblm Lewis | WA5326050 | Joint Base Lewis-Mcchord | 35,414 | 6.8 | 11.1 | 0.882 | PFOS 1–3 × its limit |
| Jblm Mcchord Field | WA5352200 | Joint Base Lewis-Mcchord | 7,290 | <MRL | 5.3 | 0.8 | PFOS 1–3 × its limit |
| Kalama City Of | WA5337550 | Kalama | 8,020 | <MRL | <MRL | 0 | No PFAS detected |
| Kelso City Of | WA5338000 | Kelso | 15,775 | <MRL | <MRL | 0 | No PFAS detected |
| Kennewick City Of | WA5338100 | Kennewick | 118,164 | 4.6 | 11.5 | 1.063 | PFOS 1–3 × its limit |
| Kent Water Department | WA5338150 | Kent | 166,421 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| King County Water District #125 | WA5341998 | Seattle | 21,904 | <MRL | <MRL | 0 | No PFAS detected |
| King County Water District #20 | WA5338950 | Seattle | 48,469 | <MRL | <MRL | 0 | No PFAS detected |
| King County Water District #49 | WA5339800 | Burien | 23,492 | <MRL | <MRL | 0 | No PFAS detected |
| King County Water District #54 | WA5339950 | Kent | 5,373 | <MRL | <MRL | 0 | No PFAS detected |
| King County Water District 119 | WA5341985 | Duvall | 3,800 | <MRL | <MRL | 0 | No PFAS detected |
| King County Water District No 90 | WA5341150 | Renton | 20,100 | <MRL | <MRL | 0 | No PFAS detected |
| Kirkland City Of | WA5342250 | Kirkland | 69,243 | <MRL | <MRL | 0 | No PFAS detected |
| Lacey Water Department | WA5343500 | Lacey | 105,178 | <MRL | <MRL | 0.31 | Hazard Index below its limit |
| Lake Chelan Reclamation District | WA5343783 | Manson | 6,798 | <MRL | <MRL | 0 | No PFAS detected |
| Lake Cushman System 5 | WA5303529 | Hoodsport | 3,675 | <MRL | <MRL | 0 | Other PFAS detected |
| Lake Forest Park Water District | WA5340950 | Lake Forest Park | 3,171 | <MRL | <MRL | 0 | No PFAS detected |
| Lake Meridian Water District | WA5341900 | Kent | 24,231 | <MRL | <MRL | 0 | No PFAS detected |
| Lakehaven Water And Sewer District | WA5341997 | Federal Way | 148,809 | <MRL | 4.1 | 0.58 | PFOS 1–3 × its limit |
| Lakewood Water District | WA5345550 | Lakewood | 82,425 | <MRL | 5.9 | 0.562 | PFOS 1–3 × its limit |
| Liberty Lake Sewer & Water District | WA5347150 | Liberty Lake | 14,500 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Long Beach Water Department | WA5348000 | Long Beach | 4,628 | <MRL | <MRL | 0 | No PFAS detected |
| Longmire | WA53NP580 | Ashford | 4,871 | <MRL | <MRL | 0 | No PFAS detected |
| Longview Water Department | WA5348100 | Longview | 57,617 | <MRL | <MRL | 0 | No PFAS detected |
| Lost Lake Property Owners Assn | WA5348345 | Coupeville | 736 | <MRL | <MRL | 0 | No PFAS detected |
| Lummi Tribal Water District | 105300002 | Bellingham | 3,699 | <MRL | <MRL | 0 | No PFAS detected |
| Lwwsd - South Shore Water System | WA5395910 | Bellingham | 10,028 | <MRL | <MRL | 0 | No PFAS detected |
| Lynden Water Department | WA5349150 | Lynden | 20,062 | <MRL | <MRL | 0 | No PFAS detected |
| Lynnwood City Of | WA5349270 | Lynnwood | 68,204 | <MRL | <MRL | 0 | No PFAS detected |
| Manchester Water District | WA5350700 | Manchester | 10,475 | <MRL | <MRL | 0 | No PFAS detected |
| Marysville Utilities | WA5351900 | Marysville | 88,582 | <MRL | <MRL | 0 | No PFAS detected |
| Mattawa City Of | WA5352000 | Mattawa | 5,370 | <MRL | <MRL | 0 | No PFAS detected |
| Mccormick Woods | WA5340529 | Port Orchard | 2,760 | <MRL | <MRL | 0 | No PFAS detected |
| Medical Lake City Of | WA5353400 | Medical Lake | 4,982 | <MRL | 4.4 | 0.53 | PFOS 1–3 × its limit |
| Mercer Island City Of | WA5353640 | Mercer Island | 31,057 | <MRL | <MRL | 0 | No PFAS detected |
| Milton City Of | WA5354950 | Milton | 8,078 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Minterbrook | WA5354740 | Tacoma | 5,083 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Model Irrigation Dist #18 | WA5355550 | Spokane | 7,903 | 4.2 | 5.3 | 0.002 | PFOS 1–3 × its limit |
| Modern Electric Water Co | WA5355600 | Spokane | 18,487 | <MRL | <MRL | 0 | No PFAS detected |
| Monroe Water System | WA5355820 | Monroe | 23,467 | <MRL | <MRL | 0 | No PFAS detected |
| Montesano City Of | WA5356000 | Montesano | 6,204 | <MRL | <MRL | 0 | No PFAS detected |
| Moses Lake City Of | WA5356300 | Moses Lake | 32,428 | <MRL | 52.2 | 5.412 | PFOS ≥ 3 × its limit |
| Mountain View-Edgewood Water Co | WA5356820 | Edgewood | 9,680 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Mountlake Terrace City Of | WA5357250 | Mountlake Terrace | 26,402 | <MRL | <MRL | 0 | No PFAS detected |
| Moxee Water Department | WA5357300 | Moxee | 5,599 | <MRL | <MRL | 0 | No PFAS detected |
| Mt. Vista - Dungeness Golf Course | 105388889 | Sequim | 517 | <MRL | <MRL | 0 | No PFAS detected |
| Mukilteo Water & Wastewater Distr | WA5357550 | Mukilteo | 31,437 | <MRL | <MRL | 0 | No PFAS detected |
| Naches Town Of | WA5358100 | Naches | 3,512 | <MRL | <MRL | 0 | No PFAS detected |
| Naval Air Station/Whidbey Island | WA5303420 | Nas Whidbey Island | 16,595 | <MRL | <MRL | 0 | No PFAS detected |
| Naval Base Kitsap At Bangor | WA5302714 | Silverdale | 16,828 | <MRL | <MRL | 0 | No PFAS detected |
| Naval Base Kitsap At Bremerton | WA5303468 | Silverdale | 11,792 | <MRL | <MRL | 0 | No PFAS detected |
| Ne Sammamish Sewer & Water District | WA5375265 | Sammamish | 9,702 | <MRL | <MRL | 0 | No PFAS detected |
| Nob Hill Water Association | WA5359700 | Yakima | 38,050 | <MRL | <MRL | 0 | No PFAS detected |
| North Bainbridge Water Co | WA5359994 | Poulsbo | 5,490 | <MRL | <MRL | 0 | No PFAS detected |
| North Beach Water | WA5363000 | Ocean Park | 8,093 | <MRL | <MRL | 0 | No PFAS detected |
| North Bend City Of | WA5360100 | North Bend | 8,710 | <MRL | <MRL | 0 | No PFAS detected |
| North City Water District | WA5339600 | Shoreline | 32,847 | <MRL | <MRL | 0 | No PFAS detected |
| North Peninsula | WA5305122 | Poulsbo | 16,449 | <MRL | <MRL | 0 | No PFAS detected |
| North Perry Ave Water District | WA5360950 | Bremerton | 24,402 | <MRL | <MRL | 0 | No PFAS detected |
| Northshore Utility District | WA5340800 | Kenmore | 99,789 | <MRL | <MRL | 0 | No PFAS detected |
| Northwest Trek | WA5361990 | Eatonville | 1,283 | <MRL | <MRL | 0 | No PFAS detected |
| Northwest Water Assoc. Inc. | WA5362000 | Lynden | 400 | 4.7 | <MRL | 0.002 | PFOA 1–3 × its limit |
| Oak Harbor City Of | WA5362650 | Oak Harbor | 23,675 | <MRL | <MRL | 0 | No PFAS detected |
| Ocean Shores Water Dept | WA5363008 | Hoquiam | 9,347 | <MRL | <MRL | 0 | No PFAS detected |
| Olympia City Of | WA5363450 | Olympia | 126,966 | 4.3 | 5.8 | 0.002 | PFOS 1–3 × its limit |
| Olympic View Water & Sewer District | WA5363600 | Edmonds | 17,784 | <MRL | <MRL | 0 | No PFAS detected |
| Omak City Of | WA5363750 | Omak | 4,940 | <MRL | <MRL | 0 | Other PFAS detected |
| Orchard Avenue Irrigation Dist 6 | WA5364000 | Spokane | 4,330 | <MRL | <MRL | 0 | No PFAS detected |
| Orting City Of | WA5364500 | Orting | 10,332 | <MRL | <MRL | 0 | No PFAS detected |
| Othello Water Department | WA5364850 | Othello | 8,755 | <MRL | <MRL | 0 | No PFAS detected |
| Pacific City Of | WA5365300 | Othello | 7,925 | <MRL | <MRL | 0.004 | Hazard Index below its limit |
| Parkland Light & Water Company | WA5366200 | Tacoma | 33,775 | 6.2 | 13.8 | 0.473 | PFOS ≥ 3 × its limit |
| Parkview Terrace | WA5366215 | Tacoma | 3,730 | <MRL | <MRL | 0.003 | Hazard Index below its limit |
| Pasadena Park Irr Dist 17 | WA5366300 | Spokane | 6,269 | <MRL | <MRL | 0 | No PFAS detected |
| Pasco Water Department | WA5366400 | Pasco | 115,102 | <MRL | <MRL | 0 | No PFAS detected |
| Pattison 500 | WA5366578 | Lacey | 4,643 | <MRL | <MRL | 0 | No PFAS detected |
| Peacock Hill | WA5366637 | Tacoma | 7,401 | <MRL | <MRL | 1.498 | Hazard Index 1–3 × its limit |
| Point Evans | WA5368065 | Tacoma | 5,211 | <MRL | <MRL | 0 | No PFAS detected |
| Port Angeles City Of | WA5368550 | Port Angeles | 28,067 | <MRL | <MRL | 0 | No PFAS detected |
| Port Angeles Composite | WA5343296 | Carlsborg | 8,872 | <MRL | <MRL | 0 | Other PFAS detected |
| Port Of Seattle/Seatac Airport | WA5303182 | Seattle | 49,483 | <MRL | <MRL | 0 | No PFAS detected |
| Port Orchard Water Dept | WA5368900 | Port Orchard | 15,355 | <MRL | <MRL | 0 | No PFAS detected |
| Port Townsend City Of | WA5369000 | Port Townsend | 17,053 | <MRL | <MRL | 0 | No PFAS detected |
| Poulsbo City Of | WA5369150 | Poulsbo | 18,400 | <MRL | <MRL | 0 | No PFAS detected |
| Prosser City Of | WA5369750 | Prosser | 8,030 | <MRL | <MRL | 0 | No PFAS detected |
| Pud #1 Of Asotin County | WA5393343 | Clarkston | 21,930 | <MRL | <MRL | 0 | No PFAS detected |
| Pullman Water Department City Of | WA5369880 | Pullman | 31,315 | <MRL | <MRL | 0 | No PFAS detected |
| Puyallup City Of | WA5370050 | Puyallup | 94,520 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Quil Ceda Village | 105300116 | Tulalip | 30,000 | <MRL | <MRL | 0 | No PFAS detected |
| Quimper | WA5305783 | Port Townsend | 14,548 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Quincy Water Department City Of | WA5370450 | Quincy | 8,415 | <MRL | <MRL | 0 | No PFAS detected |
| Quistorff | WA5370550 | Tacoma | 1,113 | <MRL | 12 | 4.418 | Hazard Index ≥ 3 × its limit |
| Raymond Water Department | WA5371500 | Raymond | 4,620 | <MRL | <MRL | 0 | No PFAS detected |
| Redmond Water System City Of | WA5371650 | Redmond | 163,335 | <MRL | 5 | 0.003 | PFOS 1–3 × its limit |
| Renton City Of | WA5371850 | Renton | 108,091 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Richland City Of | WA5372250 | Richland | 106,499 | 10.1 | 17 | 0.543 | PFOS ≥ 3 × its limit |
| Ridgefield Public Works | WA5372400 | Ridgefield | 21,225 | <MRL | <MRL | 0 | No PFAS detected |
| Rogers Group Properties I Llc | WA5389470 | North Bend | 570 | <MRL | <MRL | 0 | No PFAS detected |
| Sallal Water Association Inc | WA5375560 | North Bend | 6,600 | <MRL | <MRL | 0 | No PFAS detected |
| Sammamish Plateau Water & Sewer | WA5340900 | Sammamish | 79,362 | <MRL | 11.1 | 1.654 | PFOS 1–3 × its limit |
| Seabeck | WA5303134 | Poulsbo | 610 | <MRL | <MRL | 0 | No PFAS detected |
| Seascape Water Association | WA5307095 | Stanwood | 28 | <MRL | <MRL | 0 | No PFAS detected |
| Seattle Public Utilities | WA5377050 | Seattle | 1,161,961 | <MRL | <MRL | 0 | No PFAS detected |
| Selah City Of | WA5377400 | Selah | 9,331 | <MRL | <MRL | 0 | No PFAS detected |
| Sequim City Of | WA5377620 | Sequim | 14,293 | <MRL | <MRL | 0.003 | Hazard Index below its limit |
| Seven Lakes Water Association | WA5377660 | Stanwood | 5,823 | <MRL | <MRL | 0 | No PFAS detected |
| Shelter Bay Community Inc | WA5378155 | La Conner | 2,212 | <MRL | <MRL | 0 | No PFAS detected |
| Shelton City Of | WA5378170 | Shelton | 15,273 | <MRL | <MRL | 0 | No PFAS detected |
| Shoalwater Bay | 105300019 | Tokeland | 898 | <MRL | <MRL | 0 | No PFAS detected |
| Silver Lake Water & Sewer District | WA5379250 | Bothell | 65,033 | <MRL | <MRL | 0 | No PFAS detected |
| Silverdale Water Dist 16 | WA5379300 | Silverdale | 35,163 | <MRL | <MRL | 0 | No PFAS detected |
| Skagit County Pud 1 Judy Res | WA5379500 | Mount Vernon | 111,415 | <MRL | <MRL | 0 | Other PFAS detected |
| Skyway Water & Sewer | WA5338800 | Seattle | 12,036 | <MRL | <MRL | 0 | No PFAS detected |
| Snake River Housing Water System | WA5300710 | Yakima | 3,036 | <MRL | <MRL | 0 | No PFAS detected |
| Sno Pud 1 - Lake Stevens | WA5380907 | Everett | 67,710 | <MRL | <MRL | 0 | No PFAS detected |
| Snohomish City Of | WA5380915 | Snohomish | 16,367 | <MRL | <MRL | 0 | No PFAS detected |
| Snoqualmie Pass Utility District | WA5381048 | Snoqualmie Pass | 5,832 | <MRL | <MRL | 0 | No PFAS detected |
| Snoqualmie Water | WA5381080 | Snoqualime | 20,222 | <MRL | <MRL | 0 | No PFAS detected |
| Soos Creek Water & Sewer District | WA5340100 | Renton | 74,172 | <MRL | <MRL | 0 | No PFAS detected |
| Southwood | WA5382844 | Tacoma | 64,155 | 6.2 | 8.9 | 0.003 | PFOS 1–3 × its limit |
| Spanaway Water Company | WA5382850 | Spanaway | 34,506 | 6.2 | 8.3 | 0.373 | PFOS 1–3 × its limit |
| Spo Co Water Dist 3 Sys 1 | WA5393351 | Spokane | 19,035 | <MRL | <MRL | 0 | No PFAS detected |
| Spo Co Water Dist 3 Sys 3 | WA5393353 | Spokane | 3,768 | <MRL | <MRL | 0 | No PFAS detected |
| Spo Co Water Dist 3 Sys 4 | WA5393354 | Spokane | 6,233 | <MRL | <MRL | 0 | No PFAS detected |
| Spokane Business & Industrial Park | WA5383027 | Spokane | 5,000 | <MRL | <MRL | 0 | No PFAS detected |
| Spokane City Of | WA5383100 | Spokane | 346,138 | <MRL | 6.1 | 0.002 | PFOS 1–3 × its limit |
| Stanwood Water Dept City Of | WA5383650 | Stanwood | 17,586 | <MRL | <MRL | 0 | No PFAS detected |
| Steilacoom Town Of | WA5384000 | Steilacoom | 8,545 | <MRL | <MRL | 0 | No PFAS detected |
| Stevens Co Pud - Suncrest | WA5385202 | Loon Lake | 7,484 | <MRL | <MRL | 0 | Other PFAS detected |
| Stevens Co Pud - Valley | WA5305520 | Loon Lake | 550 | <MRL | <MRL | 0 | No PFAS detected |
| Stevens Pass Water System | WA5384245 | Leavenworth | 4,053 | <MRL | <MRL | 0 | No PFAS detected |
| Sultan Water Department | WA5384770 | Sultan | 8,424 | <MRL | <MRL | 0 | No PFAS detected |
| Summit Water & Supply Co | WA5385050 | Tacoma | 19,125 | <MRL | <MRL | 0 | Other PFAS detected |
| Sumner City Of | WA5385120 | Sumner | 16,438 | <MRL | <MRL | 0 | No PFAS detected |
| Sunnyside City Of | WA5385400 | Sunnyside | 17,194 | <MRL | <MRL | 0 | No PFAS detected |
| Suquamish | WA5386400 | Poulsbo | 4,203 | <MRL | <MRL | 0 | No PFAS detected |
| Swinomish Casino & Lodge | 105338108 | La Conner | 2,400 | <MRL | <MRL | 0 | No PFAS detected |
| Tacoma Water Division City Of | WA5386800 | Tacoma | 446,245 | <MRL | <MRL | 0.51 | Hazard Index below its limit |
| Tanglewilde Thompson Place 600 | WA5304397 | Lacey | 7,900 | <MRL | <MRL | 0 | No PFAS detected |
| Tenino City Of | WA5387400 | Tenino | 3,336 | <MRL | <MRL | 0 | No PFAS detected |
| Toppenish Water Department | WA5388850 | Toppenish | 13,382 | <MRL | <MRL | 0 | No PFAS detected |
| Trentwood Irrigation District 3 | WA5389250 | Spokane | 4,228 | 5.1 | 12 | 0.002 | PFOS ≥ 3 × its limit |
| Tukwila Water Department | WA5389500 | Tukwila | 36,298 | <MRL | <MRL | 0 | No PFAS detected |
| Tulalip Bay Water Dist #1 | 105300003 | Tulalip | 5,968 | <MRL | <MRL | 0 | No PFAS detected |
| Tumwater City Of | WA5389700 | Tumwater | 51,924 | <MRL | <MRL | 0.003 | Hazard Index below its limit |
| Union Gap Water | WA5390250 | Union Gap | 6,433 | <MRL | <MRL | 0 | No PFAS detected |
| Union Hill Water Association Inc | WA5390260 | Redmond | 8,720 | <MRL | <MRL | 0 | No PFAS detected |
| Vancouver City Of | WA5391200 | Vancouver | 373,047 | 11.5 | 18.6 | 0.662 | PFOS ≥ 3 × its limit |
| Vera Water & Power | WA5391450 | Spokane Valley | 24,692 | <MRL | <MRL | 0 | No PFAS detected |
| Vinland | WA5391923 | Poulsbo | 4,801 | <MRL | <MRL | 0 | No PFAS detected |
| Walla Walla Water Division | WA5392500 | Walla Walla | 42,959 | <MRL | <MRL | 0 | No PFAS detected |
| Wapato Waterworks | WA5392800 | Wapato | 5,255 | <MRL | <MRL | 0 | No PFAS detected |
| Warden City Of | WA5392850 | Warden | 4,674 | <MRL | <MRL | 0 | No PFAS detected |
| Washington State University | WA5393200 | Pullman | 21,506 | <MRL | <MRL | 0 | No PFAS detected |
| Washougal City Of | WA5393400 | Washougal | 21,441 | <MRL | 7.9 | 0.002 | PFOS 1–3 × its limit |
| Water District 19 | WA5338900 | Vashon | 5,335 | <MRL | <MRL | 0 | No PFAS detected |
| Wenatchee City Of | WA5394350 | Wenatchee | 43,690 | <MRL | <MRL | 0 | No PFAS detected |
| West Richland City Of | WA5394900 | West Richland | 21,231 | <MRL | <MRL | 0 | No PFAS detected |
| West Sequim Bay Inc | WA5354192 | Sequim | 2,759 | <MRL | <MRL | 0 | No PFAS detected |
| West Sound Utility District #1 | WA5302600 | Port Orchard | 28,930 | 5.7 | <MRL | 0.8 | PFOA 1–3 × its limit |
| Westport Water Department | WA5395300 | Westport | 5,346 | <MRL | <MRL | 0 | No PFAS detected |
| Whatcom County Water Dist 13 | WA5395914 | Maple Falls | 795 | <MRL | <MRL | 0 | No PFAS detected |
| White Salmon City Of | WA5396350 | White Salmon | 4,077 | <MRL | <MRL | 0 | No PFAS detected |
| Whitworth Water District 2 | WA5396601 | Mead | 26,883 | <MRL | 4.6 | 0.003 | PFOS 1–3 × its limit |
| Woodinville Water District | WA5341600 | Woodinville | 66,699 | <MRL | <MRL | 0 | No PFAS detected |
| Woodland City Of | WA5398200 | Woodland | 10,640 | <MRL | <MRL | 0 | Other PFAS detected |
| Yak Co - Terrace Heights | WA5306029 | Yakima | 8,410 | <MRL | <MRL | 0 | No PFAS detected |
| Yakima Water Division City Of | WA5399150 | Yakima | 112,858 | <MRL | <MRL | 0 | No PFAS detected |
| Yelm City Of | WA5399350 | Yelm | 17,355 | <MRL | <MRL | 0 | No PFAS detected |
Not tested under UCMR 5 (2,517)
UCMR 5 required monitoring by systems serving 3,300 or more people and by a representative sample of smaller systems. The systems below have no UCMR 5 results in EPA's data. Not tested is not the same as not detected: the absence of results says nothing about PFAS in their water.
| System | PWSID | Type | City | Population | Counties |
|---|---|---|---|---|---|
| 141St Ave Kpn 661 | WA5324781 | CWS | Lacey | 48 | Pierce County |
| 165Th Ave Water System | WA5325241 | CWS | Maple Valley | 24 | King County |
| 5 Cedars | 105300028 | CWS | Deming | 150 | Whatcom County |
| 60Th Street Water Works | WA5337925 | CWS | Snohomish | 35 | Snohomish County |
| 85 Acres | WA5322590 | CWS | Sun Valley | 55 | King County |
| Abernathy Ftc | WA53FW005 | NTNCWS | Longview | 30 | Cowlitz County |
| Acme Water District No 18 | WA5300250 | CWS | Acme | 568 | Whatcom County |
| Adams County Water Dist #1 | WA5322525 | CWS | Othello | 870 | Adams County |
| Adams Rd Community Assn | WA5301977 | CWS | Coupeville | 59 | Island County |
| Adams View | 105300042 | CWS | Wapato | 790 | Yakima County |
| Admiral Water Users Assn | WA5334544 | CWS | Moses Lake | 74 | Grant County |
| Admirals Cove Water District | WA5300410 | CWS | Freeland | 870 | Island County |
| Afc Ranch 1 | WA5303427 | CWS | Tonasket | 217 | Douglas County |
| Afc Ranch 2 | WA5300863 | CWS | Tonasket | 125 | Grant County, Kittitas County |
| Agate Bay Mhp | WA5300496 | CWS | North Bend | 40 | Whatcom County |
| Agate Beach | WA5300510 | CWS | Union | 48 | Mason County |
| Agate West | WA5300515 | CWS | Freeland | 100 | Kitsap County |
| Agotaras Water System | WA5361390 | CWS | Gig Harbor | 138 | Pierce County |
| Agrex Water System | WA53AB279 | NTNCWS | Ephrata | 25 | Grant County |
| Agrinorthwest Riverbend | WA5306559 | CWS | Pasco | 59 | Benton County, Walla Walla County |
| Ahearn Water System | WA5325384 | CWS | Coupeville | 91 | Island County |
| Albion Water Dept | WA5300800 | CWS | Albion | 600 | Whitman County |
| Alcoa | WA5300750 | NTNCWS | Malaga | 50 | Chelan County |
| Alder Lake | WA5326995 | CWS | Port Orchard | 85 | Pierce County |
| Alderbrook Water Co | WA5301050 | CWS | Union | 2,154 | Mason County |
| Alderdale Water Assn | WA5326214 | CWS | Prosser | 171 | Klickitat County |
| Aldergrove Water Assoc. | WA5301200 | CWS | Lynden | 120 | Whatcom County |
| Alderwood East | WA5301265 | CWS | Sequim | 39 | Clallam County |
| Alderwood Estates | WA5301270 | CWS | Puyallup | 635 | Pierce County |
| Aleck Bay Park Water System | WA5301338 | CWS | Lopez Island | 40 | San Juan County |
| Algona Water Dept | WA5301450 | CWS | Algona | 3,300 | King County |
| Allan Bros Warehouse | WA5301608 | NTNCWS | Naches | 1,000 | Yakima County |
| Allyn Carey | WA53AC551 | CWS | Shelton | 45 | Mason County |
| Allyn Shopping Center | WA5301695 | CWS | Tacoma | 414 | Mason County |
| Almira Water System | WA5301700 | CWS | Almira | 372 | Lincoln County |
| Aloha Pines Estates Water System | WA5306319 | CWS | Elk | 95 | Spokane County |
| Alpha Modular Structures | WA5306218 | NTNCWS | Chehalis | 60 | Lewis County |
| Alpine Acres Community Association | WA5301822 | CWS | Cashmere | 51 | Chelan County |
| Alpine Hills | WA5301826 | CWS | Tacoma | 363 | Thurston County |
| Alpine Mobile Estates | WA5305831 | CWS | Port Orchard | 71 | Thurston County |
| Alpine Mobile Manor | WA5301830 | CWS | Issaquah | 45 | King County |
| Alpine Water Association | WA5307667 | CWS | Falls City | 58 | King County |
| Alpine Water District | WA5325315 | CWS | Cashmere | 2,255 | Chelan County |
| Alps Mobile Home Park | WA5314572 | CWS | Yakima | 150 | Yakima County |
| Alta Forest Products | WA53AC650 | NTNCWS | Port Orchard | 90 | Mason County |
| Alta Lake Golf Course Plat | WA5319204 | CWS | East Wentachee | 161 | Okanogan County |
| Amboy Clark Public Utilities | WA5304625 | CWS | Vancouver | 991 | Clark County, Cowlitz County |
| Ames Lake Water Assoc Inc | WA5302055 | CWS | Redmond | 3,224 | King County |
| Amg Aluminum North America | WA5337921 | NTNCWS | Malaga | 50 | Chelan County |
| Andersen Dairy Inc | WA5305366 | NTNCWS | Battle Ground | 64 | Clark County |
| Anderson Creek Water Association | WA5302300 | CWS | Bellingham | 41 | Whatcom County |
| Anderson Hay & Grain Co | WA5302330 | NTNCWS | Yakima | 130 | Kittitas County |
| Andrews First | WA5317241 | CWS | Tacoma | 299 | Thurston County |
| Andrus Water System | WA5326280 | NTNCWS | Spokane | 41 | Spokane County |
| Angel Of The Winds | 105311105 | NTNCWS | Arlington | 2,303 | Snohomish County |
| Apple Acres Village | WA5302735 | CWS | Yakima | 212 | Chelan County |
| Apple King Llc | WA5362020 | NTNCWS | Yakima | 100 | Yakima County |
| Appleway Trailer Court | WA5300603 | CWS | Tonasket | 54 | Okanogan County |
| Aqua Copia/Horse Country Estates | WA5334400 | CWS | Snohomish | 250 | Snohomish County |
| Aqua Hills Marysville | WA5309404 | CWS | Port Orchard | 113 | Snohomish County |
| Arcadia Estates | WA5302857 | CWS | Union | 110 | Mason County |
| Arden Hills Water System | WA5302885 | CWS | Colville | 80 | Stevens County |
| Arlenes Addition | WA5302942 | CWS | Burbank | 480 | Walla Walla County |
| Arlington East Mutual Water Assn. | WA5302948 | CWS | Arlington | 100 | Snohomish County |
| Arlington Heights Water Co Inc | WA5311134 | CWS | Arlington | 57 | Snohomish County |
| Arlington Terrace | WA5327241 | CWS | Port Orchard | 104 | Snohomish County |
| Arlington View Estates Water Assoc | WA5302945 | CWS | Arlington | 75 | Snohomish County |
| Aromatics | WA53AD027 | NTNCWS | Moses Lake | 40 | Franklin County |
| Arrowhead Beach Coop Water Assoc | WA5303000 | CWS | Mt Vernon | 168 | Island County |
| Arrowhead Ranch | WA53AB980 | NTNCWS | Cle Elum | 140 | Okanogan County |
| Artesian Water District 8 | WA5303150 | CWS | College Place | 302 | Walla Walla County |
| Ashford Water District | WA5303200 | CWS | Ashford | 1,141 | Pierce County |
| Ashley Lane | WA5363777 | CWS | Port Orchard | 30 | Kitsap County |
| Asotin Water Dept | WA5303250 | CWS | Asotin | 2,531 | Asotin County |
| Aspen Reflections Landing Water | WA5305782 | CWS | Elk | 49 | Pend Oreille County |
| Aspinwall Estates | WA5301463 | CWS | Tacoma | 93 | Thurston County |
| Aston Estates | WA5309066 | CWS | Tonasket | 141 | Okanogan County |
| Auburn Park Community Llc | WA5303344 | CWS | Port Orchard | 202 | King County |
| Aust 210 | WA5301222 | CWS | Lacey | 35 | Lewis County |
| Avellana Water | WA5326801 | CWS | Poulsbo | 100 | Kitsap County |
| Ayock Beach Improvement | WA5303450 | CWS | Port Orchard | 129 | Mason County |
| Azwell Orchards | WA5303523 | CWS | Tonasket | 7 | Chelan County |
| B & D Mobile Court | 105300073 | CWS | Toppenish | 45 | Yakima County |
| Baby Island Heights Water Assoc | WA5303660 | CWS | Freeland | 211 | Island County |
| Bacus Road #1 | WA5364327 | CWS | Freeland | 62 | Skagit County |
| Badger Canyon Ranchettes #2 | WA5332074 | CWS | Port Orchard | 70 | Benton County |
| Badger Canyon Water Assn | WA5300604 | CWS | Kennewick | 40 | Benton County |
| Badger Lake Estates Llc | WA5346985 | CWS | Port Orchard | 56 | Spokane County |
| Badger Mountain Irrigation District | WA5322617 | CWS | Kennewick | 2,331 | Benton County |
| Bainbridge Island Child Care Cntrs | WA5305369 | NTNCWS | Port Orchard | 45 | Kitsap County |
| Bainbridge Island Pub Wrks | WA5307138 | NTNCWS | Bainbridge Island | 36 | Kitsap County |
| Baker Produce Zillah | WA53AD263 | NTNCWS | Yakima | 65 | Yakima County |
| Baker View Water Assoc | WA5304050 | CWS | Lynden | 40 | Whatcom County |
| Bakerview Terrace Comm Club | WA5304025 | CWS | Mt Vernon | 34 | Island County |
| Bar 80 Ranchettes | WA5332071 | CWS | Benton City | 32 | Benton County |
| Bar B Estate Manor | WA5322751 | CWS | Tacoma | 96 | Mason County |
| Bardin Hills Farmworker Housing | WA53AC034 | CWS | Wenatchee | 36 | Chelan County |
| Barleans | WA5306429 | NTNCWS | Ferndale | 163 | Whatcom County |
| Basic American Foods | WA5301983 | NTNCWS | Moses Lake | 100 | Grant County |
| Basin City Water Sewer District | WA5304461 | CWS | Mesa | 1,740 | Franklin County |
| Basin View Water Association | WA5304530 | CWS | Othello | 60 | Adams County |
| Basin Water Sources Inc | WA5304600 | CWS | Cle Elum | 1,158 | Grant County |
| Battle Ground High And Lewisville E | WA5304710 | NTNCWS | Battle Ground | 2,835 | Clark County |
| Bauers Landing Lodge | WA5305836 | CWS | Cashmere | 291 | Douglas County |
| Bay Center | WA5304815 | CWS | Raymond | 579 | Pacific County |
| Bay City Properties | WA5304847 | CWS | Raymond | 90 | Grays Harbor County |
| Bay East | WA5304852 | CWS | Union | 96 | Mason County |
| Bay Light | WA5320834 | NTNCWS | Clinton | 100 | Island County |
| Bayshore Water System | WA5304930 | CWS | Mt Vernon | 56 | Island County |
| Bayview Beach Water District | WA5305535 | CWS | Freeland | 1,035 | Island County |
| Bayview Estates Water Company | WA5304956 | CWS | Oak Harbor | 227 | Island County |
| Bayview Meadows Water System | WA5327849 | CWS | Oak Harbor | 34 | Island County |
| Bayview School | WA5315113 | NTNCWS | Oak Harbor | 75 | Island County |
| Baywood Village Mobile Home Park | WA5336754 | CWS | Sequim | 90 | Clallam County |
| Bc Water Co | WA53AA373 | CWS | Kennewick | 1,262 | Benton County |
| Bct Inc | WA5306643 | NTNCWS | Wallula | 58 | Walla Walla County |
| Beach | 105300109 | CWS | Sequim | 45 | Clallam County |
| Beachcomber H2O Co | WA5304979 | CWS | Freeland | 310 | Island County |
| Beachwood Water Company | WA5304980 | CWS | Coupeville | 90 | Island County |
| Beacon Hill East | WA53AD882 | CWS | Kelso | 190 | Cowlitz County |
| Beacon Point Community Club | WA5305025 | CWS | Shelton | 158 | Mason County |
| Bear Cub | WA5316610 | CWS | Port Orchard | 155 | Kitsap County |
| Bear Mountain Water District | WA5307155 | CWS | Chelan | 177 | Chelan County, Douglas County |
| Beards Cove | WA5305100 | CWS | Shelton | 1,100 | Mason County |
| Beau View Water | WA5320776 | CWS | Puyallup | 30 | Pierce County |
| Beaux Arts Water Department | WA5305160 | CWS | Beaux Arts | 345 | King County |
| Beaver Valley School | WA5307929 | NTNCWS | Cashmere | 26 | Chelan County |
| Bel Aire Cove | WA5305243 | CWS | Union | 32 | Mason County |
| Belfair Water District 1 | WA5305350 | CWS | Belfair | 4,432 | Mason County |
| Belfern Water Association | WA5305370 | CWS | Lynden | 228 | Whatcom County |
| Belfern West | WA5309899 | CWS | Lynden | 60 | Whatcom County |
| Bell Bay Jackson Water Association | WA5305450 | CWS | Lynden | 350 | Whatcom County |
| Bell Woods | WA53AB228 | CWS | Port Orchard | 70 | Clallam County |
| Bellwood A | WA5305534 | CWS | Union | 163 | Mason County |
| Belwood Park | WA5305640 | CWS | Tacoma | 66 | Thurston County |
| Berthusen Road Water Association | WA5305875 | CWS | Lynden | 409 | Whatcom County |
| Bertsch Subdivision Water Assn | WA5305885 | CWS | Yakima | 100 | Yakima County |
| Bethel Community | WA5305950 | CWS | Port Orchard | 30 | Kitsap County |
| Bethel East | WA5305965 | CWS | Port Orchard | 127 | Kitsap County |
| Bethel Green Acres Water Assn | WA5305980 | CWS | Tacoma | 522 | Pierce County |
| Bethel Ranchettes Mutual Water Co | WA5306015 | CWS | Port Orchard | 65 | Pierce County |
| Bethel Water Co | WA5305948 | CWS | Lacey | 270 | Pierce County |
| Bets Water System | WA5339991 | CWS | Coupeville | 50 | Island County |
| Beulah Park Community | WA5306100 | CWS | Port Orchard | 106 | King County |
| Beverly Beach Homeowners | WA5306200 | CWS | Port Orchard | 50 | Thurston County |
| Beverly Beach Improvement Club | WA5306147 | CWS | Mt Vernon | 56 | Island County |
| Beverly Water District | WA5306350 | CWS | Mattawa | 120 | Grant County |
| Bickleton Community | WA53AC759 | CWS | Goldendale | 277 | Klickitat County |
| Big Bend Landowners Association | WA5306630 | CWS | Monroe | 419 | Snohomish County |
| Billington | WA5380710 | CWS | Maple Valley | 34 | King County |
| Bingen Water Dept | WA5306900 | CWS | Bingen | 1,758 | Klickitat County |
| Birch Bay Square Water Operation | WA5302395 | NTNCWS | Lynden | 915 | Whatcom County |
| Bird Dog Family Ltd Partnership Ii | WA5352172 | CWS | Othello | 186 | Adams County |
| Bird Electric | WA5307115 | NTNCWS | Belfair | 61 | Kitsap County |
| Biscay Duplexes 675 | WA5307160 | CWS | Lacey | 36 | Thurston County |
| Black Diamond Water Dept | WA5307220 | CWS | Black Diamond | 6,407 | King County |
| Black Diamond Water District | WA5307221 | CWS | Port Angeles | 452 | Clallam County |
| Black Lake Acres | WA5360846 | CWS | Olympia | 104 | Thurston County |
| Black Lake Bible Camp & Conf Ctr | WA5307222 | CWS | Olympia | 477 | Thurston County |
| Black Lake Estates | WA5326071 | CWS | Tacoma | 329 | Thurston County |
| Blackmans Lake Water District | WA5307250 | CWS | 93 | Snohomish County | |
| Blalock Orchard Dist 10 | WA5307350 | CWS | Walla Walla | 250 | Walla Walla County |
| Blalock Orchards Dist 12 | WA5307400 | CWS | Walla Walla | 193 | Walla Walla County |
| Blanchard Edison Water Assn. Inc. | WA5307450 | CWS | Bow | 1,480 | Skagit County |
| Bloedel Reserve | WA5300924 | NTNCWS | Bremerton | 559 | Kitsap County |
| Blue Sky Country Farms | WA5307516 | CWS | Port Orchard | 48 | Spokane County |
| Blyn - 7 Cedars Consolidated | 105300083 | NTNCWS | Sequim | 2,630 | Clallam County |
| Boise Cascade - Arden Lumber | WA5306837 | NTNCWS | Springdale | 64 | Stevens County |
| Boistfort Valley | WA5307610 | CWS | Adna | 2,389 | Lewis County |
| Bolduc Community | WA5307620 | CWS | Union | 51 | Mason County |
| Bon Air Community Club Inc. | WA5307630 | CWS | Oak Harbor | 160 | Island County |
| Bonneville Dam Power House 2 | WA5340051 | NTNCWS | Cascade Locks | 62 | Skamania County |
| Bonnie View Water | WA5307700 | CWS | Oak Harbor | 50 | Island County |
| Boots & Saddles 662 | WA5307730 | CWS | Lacey | 150 | Pierce County |
| Borton & Sons Inc | WA5304410 | NTNCWS | Yakima | 159 | Yakima County |
| Boston Harbor | WA5307850 | CWS | Olympia | 1,153 | Thurston County |
| Bradley Denny | WA5384619 | NTNCWS | 66 | Thurston County | |
| Brandt Point | WA5316190 | CWS | Sequim | 32 | Clallam County |
| Braunwood Estates | WA5303336 | CWS | Auburn | 35 | King County |
| Brays Landing Water Users | WA5307289 | CWS | Wenatchee | 228 | Douglas County |
| Brewster City Of | WA5308300 | CWS | Brewster | 3,843 | Okanogan County |
| Brewster Flat Domestic Water Assn | WA5308290 | CWS | Brewster | 542 | Okanogan County |
| Brianwood | WA5306651 | CWS | Poulsbo | 48 | Kitsap County |
| Briarwood Water System | WA5308324 | CWS | Freeland | 44 | Island County |
| Bridge Road | WA53AB775 | CWS | Vancouver | 25 | Clark County |
| Bridge Water Resources | WA5352075 | CWS | Raymond | 69 | Pacific County |
| Bridgehaven Community Club | WA5308330 | CWS | Port Ludlow | 623 | Jefferson County |
| Bridgeport City Of | WA5308350 | CWS | Bridgeport | 2,214 | Douglas County |
| Bridgeview Homesites Water Assn | WA5308356 | CWS | Yakima | 80 | Yakima County |
| Bridle Moor Water Association | WA5308364 | CWS | Yakima | 44 | Yakima County |
| Bridle Trails South Water System | WA5312232 | CWS | Ravensdale | 42 | King County |
| Briggs Nursery | WA5302499 | NTNCWS | Shelton | 150 | Grays Harbor County |
| Brinnon School District 46 | WA5321689 | NTNCWS | Brinnon | 100 | Jefferson County |
| Brinnon Water Co Inc | WA5324029 | NTNCWS | Brinnon | 31 | Jefferson County |
| Brixey H2A | WA53AD929 | CWS | Yakima | 100 | Grant County |
| Brocious Water System | WA53AD822 | CWS | Yakima | 100 | Yakima County |
| Bronson Beach Club | WA5308740 | CWS | Tenino | 225 | Thurston County |
| Brookdale Owners Association | WA5329629 | CWS | Tacoma | 35 | Pierce County |
| Brookhaven | WA5308760 | CWS | Tacoma | 32 | Kitsap County |
| Brookside | WA5346002 | CWS | Woodland | 100 | Clark County, Cowlitz County |
| Brown Taylor Water Co Inc | WA5308815 | CWS | Yakima | 30 | Yakima County |
| Bruce Water System | WA5309540 | NTNCWS | Othello | 210 | Adams County |
| Brutus Water System | WA5308914 | CWS | Arlington | 48 | Island County |
| Buck Creek | WA5308940 | CWS | Raymond | 165 | Pierce County |
| Buckhorn Mountain Water System | WA53AB409 | NTNCWS | 100 | Okanogan County | |
| Bucklin | WA5366936 | CWS | Tacoma | 402 | Kitsap County |
| Bucoda Water Dept | WA5309100 | CWS | Bucoda | 579 | Thurston County |
| Buena Vista Community Club | WA5309150 | CWS | Mt Vernon | 200 | Island County |
| Buena Vista Estates | WA5309155 | CWS | Sequim | 42 | Clallam County |
| Bullitt Center | WA53AD305 | NTNCWS | Seattle | 175 | King County |
| Bunk Foss System | WA5326140 | CWS | Arlington | 36 | Snohomish County |
| Burbank Business Park | WA53AB436 | NTNCWS | Walla Walla | 1,983 | Walla Walla County |
| Burbank Heights | WA5309350 | CWS | Burbank | 177 | Walla Walla County |
| Burbank Irrigation District 4 | WA5309300 | CWS | Pasco | 527 | Walla Walla County |
| Burley Bible Church | WA5309445 | NTNCWS | Port Orchard | 176 | Kitsap County |
| Burley Water Assn | WA5309450 | CWS | Port Orchard | 50 | Kitsap County |
| Burman Acres Water | WA5309570 | CWS | Yakima | 92 | Yakima County |
| Burnett Water District | WA5309600 | CWS | Buckley | 109 | Pierce County |
| Burns Point | WA5309650 | CWS | Port Orchard | 182 | Thurston County |
| Burnsville 676 | WA5305329 | CWS | Lacey | 183 | Thurston County |
| Burton Water Cooperative | WA5309800 | CWS | Vashon | 964 | King County |
| Bush Point Terrace Comm Club Inc. | WA5309930 | CWS | Freeland | 55 | Island County |
| Bush Point Trac Park | WA5309900 | CWS | Coupeville | 111 | Island County |
| Butler Cove Water Company | WA5310050 | CWS | Port Orchard | 278 | Thurston County |
| Butterfield Water Company | WA5310100 | CWS | Yakima | 108 | Yakima County |
| Bybee Clyde W. | WA5303392 | NTNCWS | Yakima | 76 | Benton County |
| Bywater Bay | WA5302043 | CWS | Port Townsend | 628 | Jefferson County |
| Cal Waterworks | WA5331040 | CWS | Freeland | 239 | Island County |
| Calman James L. | WA5302011 | CWS | Maple Falls | 40 | Whatcom County |
| Calmor Cove Club | WA5310562 | CWS | Lynden | 44 | Whatcom County |
| Camaloch Association | WA5310580 | CWS | Coupeville | 825 | Island County |
| Camaloch Evergreen Acres | WA5305926 | NTNCWS | Stanwood | 50 | Island County |
| Camano City Community Club Inc | WA5310590 | CWS | Stanwood | 246 | Island County |
| Camano Co-Op Water & Power Co | WA5310600 | CWS | Mt Vernon | 1,071 | Island County |
| Camano Colony Water System Inc | WA5310595 | CWS | Mt Vernon | 53 | Island County |
| Camano Hills Water Company Inc | WA5301429 | CWS | Coupeville | 286 | Island County |
| Camano Island Summit Assoc. | WA5308344 | CWS | Mt Vernon | 42 | Island County |
| Camano Laguna Vista Water Assoc | WA5310725 | CWS | Stanwood | 310 | Island County |
| Camano Lutheran Church | WA5315203 | NTNCWS | Coupeville | 75 | Island County |
| Camano Shores Community | WA5310744 | CWS | Stanwood | 79 | Island County |
| Camano Sunrise Water Assn #1 | WA5310746 | CWS | Mt Vernon | 76 | Island County |
| Camano Sunrise Water Assn #2 | WA5329669 | CWS | Mt Vernon | 122 | Island County |
| Camano Sunset Water System | WA5326951 | CWS | Mount Vernon | 47 | Island County |
| Camano Vista Water District | WA5310748 | CWS | Coupeville | 591 | Island County |
| Camano Water Association | WA5310750 | CWS | Coupeville | 2,592 | Island County |
| Camano West Water Association | WA5310755 | CWS | Stanwood | 167 | Island County |
| Camelot And Western Skies | WA5310808 | CWS | Tacoma | 228 | Thurston County |
| Camelot Subdivision | WA5310805 | CWS | Kelso | 142 | Cowlitz County |
| Camp Arnold-Weyerhaeuser | WA53AA641 | NTNCWS | Port Orchard | 60 | Cowlitz County |
| Camp Benbow | WA5310815 | CWS | Graham | 130 | Pierce County |
| Camp David | WA5310838 | CWS | Poulsbo | 53 | Kitsap County |
| Campbells Glen | WA5310988 | CWS | Clinton | 62 | Island County |
| Campo Hacienda | WA5310992 | CWS | Oak Harbor | 123 | Island County |
| Campo Verde Street & Water Assn | WA5310994 | CWS | Port Orchard | 36 | Pierce County |
| Canal Mutual Water | WA5310999 | CWS | Union | 167 | Mason County |
| Candlewood Mobile Manor | WA5311002 | CWS | Port Orchard | 211 | Thurston County |
| Canterbrook Village Apartments | WA5301984 | CWS | Port Orchard | 355 | Pierce County |
| Canterwood Water System | WA5305859 | CWS | Gig Harbor | 1,805 | Pierce County |
| Canyon Farm Camp | WA53AD564 | CWS | Pasco | 96 | Franklin County |
| Canyon Village Water System Inc | WA5305801 | CWS | Yakima | 310 | Benton County |
| Canyonwood Beach Water Supply | WA5311030 | CWS | Union | 43 | Mason County |
| Cape George Colony Club Inc | WA5311050 | CWS | Belfair | 1,022 | Jefferson County |
| Cape Horn Maintenance Company | WA5311060 | CWS | Mt Vernon | 940 | Skagit County |
| Cape Horn Skye Grade School | WA5311062 | NTNCWS | Woodland | 610 | Skamania County |
| Cape San Juan Water District | WA5311065 | CWS | Friday Harbor | 164 | San Juan County |
| Carbonado Water Dept | WA5311100 | CWS | Carbonado | 875 | Pierce County |
| Care Free Acres | WA5311135 | CWS | Coupeville | 30 | Island County |
| Carlsborg Lud 10 12 13 14 | WA5300307 | CWS | Carlsborg | 1,349 | Clallam County |
| Carlsborg Mobile Estates | WA5300029 | CWS | Sequim | 69 | Clallam County |
| Carlyon Beach Homeowners | WA5311159 | CWS | Olympia | 1,273 | Thurston County |
| Carnation Farms | WA5311180 | NTNCWS | Carnation | 179 | King County |
| Carnation Water System City Of | WA5311200 | CWS | Mt Vernon | 2,400 | King County |
| Carnhope Irrigation District 7 | WA5311250 | CWS | Spokane Valley | 1,602 | Spokane County |
| Carousel Day Care | WA5301461 | NTNCWS | Port Orchard | 63 | Kitsap County |
| Carriage Club Estates | WA5373240 | CWS | Port Orchard | 230 | Thurston County |
| Carrolls Water Assn | WA5311300 | CWS | Napavine | 449 | Cowlitz County |
| Carson | WA5311340 | CWS | Carson | 3,015 | Skamania County |
| Carson Industrial Site | WA5368840 | NTNCWS | Carson | 62 | Skamania County |
| Cascade Crest | WA5331203 | CWS | Port Orchard | 55 | Snohomish County |
| Cascade Foothills | WA5307285 | CWS | Tonasket | 61 | Douglas County |
| Cascade Highlands | WA5345061 | CWS | Tacoma | 93 | Pierce County |
| Cascade Highlands North | WA5355631 | CWS | Tacoma | 119 | Pierce County |
| Cascade Mhp | WA5367310 | CWS | Morton | 48 | Lewis County |
| Cascade River Community Club | WA5311494 | CWS | Marblemount | 107 | Skagit County |
| Cascade Valley Water District | WA5311500 | CWS | Moses Lake | 379 | Grant County |
| Cascade View Estates #1 | WA53AA044 | CWS | Cle Elum | 28 | Kittitas County |
| Cascade View Estates #3 | WA53AA046 | CWS | Cle Elum | 25 | Kittitas County |
| Cascade View Estates #4 | WA5306581 | CWS | Cle Elum | 30 | Kittitas County |
| Cascade View Road Water System | WA5328020 | CWS | Freeland | 26 | Island County |
| Cascade Village Mhp | WA5311488 | CWS | Ellensburg | 164 | Grant County |
| Cascade Vista Hoa | WA5308072 | CWS | Port Orchard | 260 | Snohomish County |
| Cascades Camp & Conference Center | WA5346074 | NTNCWS | Port Orchard | 131 | Thurston County |
| Cascadia Park Water Company | WA5311625 | CWS | Yakima | 93 | Yakima County |
| Cashmere Water Department | WA5311700 | CWS | Cashmere | 5,815 | Chelan County |
| Cathlamet Water Dept | WA5311850 | CWS | Cathlamet | 1,636 | Wahkiakum County |
| Cattle Point Water District | WA5342751 | CWS | Friday Harbor | 63 | San Juan County |
| Cayou Valley Homeowners Assoc | WA5311860 | CWS | Eastsound | 31 | San Juan County |
| Ccao/Yfo Complex | WA5307406 | NTNCWS | Yakima | 115 | Yakima County |
| Cedar Creek Corrections Center | WA5311882 | CWS | Littlerock | 639 | Thurston County |
| Cedar Crest | WA5311887 | CWS | Tacoma | 2,954 | Pierce County |
| Cedar Crest Mobile Home Park | WA5311888 | CWS | Olympia | 92 | Pierce County |
| Cedar Falls Supply | WA5311900 | NTNCWS | Seattle | 184 | King County |
| Cedar Glen Mobile Home Park | WA5311912 | CWS | Port Orchard | 284 | Kitsap County |
| Cedar Grove | WA5311914 | CWS | Tacoma | 156 | Mason County |
| Cedar Grove Composting Water System | WA5326461 | NTNCWS | Port Orchard | 50 | King County |
| Cedar Lynn Water Assoc | WA5312112 | CWS | Lynden | 116 | Whatcom County |
| Cedar Mountain Homeowners Assoc | WA5302996 | CWS | Port Orchard | 106 | King County |
| Cedar Park | WA5311975 | CWS | Shelton | 53 | Thurston County |
| Cedar Ridge 617 | WA5302938 | CWS | Lacey | 186 | Thurston County |
| Cedar Shores 677 | WA5304953 | CWS | Lacey | 90 | Thurston County |
| Cedar Springs Camp | WA5317901 | CWS | Lake Stevens | 308 | Snohomish County |
| Cedar View Tracts Comm Club | WA5306151 | CWS | Port Orchard | 90 | Mason County |
| Cedar Villa | WA5311998 | CWS | Chehalis | 32 | Lewis County |
| Cedarbrook | WA5314001 | CWS | Tacoma | 93 | Kitsap County |
| Cedarhearth Water | WA5396889 | CWS | Freeland | 37 | Island County |
| Cedars Mobile Manor | WA5311947 | CWS | Port Orchard | 62 | Pierce County |
| Cedarwood 763 | WA5312100 | CWS | Lacey | 153 | Thurston County |
| Cedarwood South Union Estates | WA5300253 | CWS | Tacoma | 119 | Thurston County |
| Centerville Grade School | WA5321127 | NTNCWS | Centerville | 115 | Klickitat County |
| Central Mobile Home Park | WA5312170 | CWS | Ellensburg | 110 | Kittitas County |
| Central Pre Mix - Sullivan Rd | WA5306164 | NTNCWS | Waverly | 130 | Spokane County |
| Century Water Association | WA5300601 | CWS | Lynden | 110 | Whatcom County |
| Ch2O | WA5302819 | NTNCWS | Olympia | 51 | Thurston County |
| Chamonix Village | WA5312235 | CWS | Baring | 53 | King County |
| Charlene Heights Well Co | WA5312239 | CWS | Yakima | 30 | Yakima County |
| Chattaroy Springs Water Assn | WA5312247 | CWS | Chattaroy | 43 | Spokane County |
| Chattaroy Valley Mobile Estates | WA5312243 | CWS | Spokane | 333 | Spokane County |
| Chealco Water Supply | WA5312270 | CWS | Arlington | 78 | Snohomish County |
| Chehalis Tribal Housing | 105300027 | CWS | Oakville | 620 | Grays Harbor County |
| Chelan Co Pud - Chelan Ridge | WA5300631 | CWS | Wenatchee | 2,429 | Chelan County |
| Chelan Co Pud - Dryden | WA5320100 | CWS | Wenatchee | 163 | Chelan County |
| Chelan Co Pud - Olalla Canyon | WA5363408 | CWS | Wenatchee | 67 | Chelan County |
| Chelan Co Pud1 - Peshastin | WA5367050 | CWS | 1,397 | Chelan County | |
| Chelan Falls Water District | WA5312350 | CWS | Wenatchee | 335 | Chelan County |
| Chelan Park Ranches Water Assn | WA5356211 | CWS | Port Orchard | 53 | Chelan County |
| Cheney Public Schools | WA5300545 | NTNCWS | Waverly | 36 | Spokane County |
| Cherokee Bay Community Club Inc | WA5311626 | CWS | Port Orchard | 2,400 | King County |
| Cherokee Strip Hoa & Water | WA5312450 | CWS | Port Orchard | 59 | Mason County |
| Cherry Creek | WA5323101 | CWS | Sun Valley | 138 | King County |
| Cherry Park | WA5312560 | CWS | Union | 111 | Mason County |
| Cherrywood Mobile Home Manor | WA5312630 | CWS | Seattle | 120 | Pierce County |
| Chewelah Water Dept North | WA5309156 | CWS | Chewelah | 350 | Stevens County |
| Chewelah Water Dept South | WA5312750 | CWS | Chewelah | 2,615 | Stevens County |
| Chico Heights Community | WA5324042 | CWS | Kirkland | 30 | Kitsap County |
| Chief Kitsap Academy | 105388890 | NTNCWS | Suquamish | 120 | Kitsap County |
| Chinook Estates | WA5336294 | CWS | Puyallup | 455 | Pierce County |
| Chinook Water District | WA5312800 | CWS | Chinook | 664 | Pacific County |
| Chippewa Water District | WA5320501 | CWS | Ione | 185 | Pend Oreille County |
| Chiwawa Communities Assn | WA5312850 | CWS | Leavenworth | 352 | Chelan County |
| Christ Lutheran Church | WA5313895 | NTNCWS | Port Orchard | 83 | Mason County |
| Chuckanut Trails Water System | WA5301383 | CWS | Lynden | 158 | Whatcom County |
| Circle C Ranch | WA5329067 | CWS | Wauna | 31 | Pierce County |
| Citizens Water Association | WA5301000 | CWS | Port Orchard | 60 | Pierce County |
| Cjc Keys Washington Llc | WA5303074 | NTNCWS | Chehalis | 40 | Lewis County |
| Clallam Bay Sekiu | WA5313200 | CWS | Carlsborg | 1,719 | Clallam County |
| Clark & Owens Water System | WA5315864 | CWS | Tacoma | 26 | Pierce County |
| Clark Addition Water System | WA53AB809 | CWS | Pasco | 189 | Franklin County |
| Clarks Creek Llc | WA5322880 | CWS | Puyallup | 20 | Pierce County |
| Classic Heights | WA5363381 | CWS | Tacoma | 480 | Thurston County |
| Cle Elum Water Department | WA5313500 | CWS | Cle Elum | 2,213 | Kittitas County |
| Clear Creek Estates | WA5347431 | CWS | Tacoma | 101 | Kitsap County |
| Clear Lake Water District | WA5304512 | CWS | Port Orchard | 317 | Pierce County |
| Clear Lake Water Users Assn | WA5313525 | CWS | Reardan | 182 | Spokane County |
| Clearwater Domestic Water Assn | WA5313550 | CWS | Pasco | 78 | Franklin County |
| Clearwood | WA5313615 | CWS | Yelm | 2,956 | Thurston County |
| Clerget 253 | WA5338171 | CWS | Lacey | 48 | Pierce County |
| Clifton Beach Tracts Co Op | WA5313800 | CWS | Port Orchard | 65 | Mason County |
| Clifton Pebble Beach | WA5313850 | CWS | Port Orchard | 52 | Mason County |
| Cliftonwood | WA5332027 | CWS | Port Orchard | 35 | Kitsap County |
| Clinton Water District | WA5313900 | CWS | Clinton | 1,980 | Island County |
| Cloister | WA5327091 | CWS | Olympia | 29 | Thurston County |
| Clouse Water System | WA53AE123 | CWS | Port Orchard | 40 | Pierce County |
| Club Green Meadows | WA5328591 | NTNCWS | Vancouver | 545 | Clark County |
| Coach Country Corral | WA5313915 | CWS | Port Orchard | 170 | Pierce County |
| Coach Post Mobile Park | WA5313923 | CWS | Port Orchard | 65 | Thurston County |
| Cole | WA5335363 | CWS | Tacoma | 257 | Pierce County |
| Cole Point Association | WA5313943 | CWS | Port Orchard | 37 | Pierce County |
| Coleman Butte Water Assn | WA5313940 | CWS | Tonasket | 250 | Okanogan County |
| Collins Lake Community Club | WA5314057 | CWS | Port Orchard | 322 | Mason County |
| Colony Mountain | WA5314069 | CWS | Lynden | 213 | Skagit County |
| Colony Surf Water Supply | WA5314080 | CWS | Lilliwaup | 297 | Mason County |
| Colton Water Department | WA5314100 | CWS | Colton | 632 | Whitman County |
| Columbia Bean | WA53AB978 | NTNCWS | Cle Elum | 45 | Grant County |
| Columbia Cedar | WA5308174 | NTNCWS | Kettle Falls | 70 | Ferry County |
| Columbia Crest Elementary School | WA5314127 | NTNCWS | Port Orchard | 222 | Pierce County |
| Columbia Crest Estates | WA5307200 | CWS | Napavine | 48 | Cowlitz County |
| Columbia Generating Station | WA5392024 | NTNCWS | Richland | 1,302 | Benton County |
| Columbia Place Llc | WA5353263 | CWS | Portland | 125 | Benton County |
| Columbia Pulp I | WA53AD699 | NTNCWS | Port Orchard | 25 | Columbia County |
| Columbia Rim Water System | WA5314169 | CWS | Yakima | 77 | Klickitat County |
| Columbia Riverfront Rv Park | WA5300946 | CWS | Woodland | 233 | Cowlitz County |
| Columbia Rock And Aggregates | WA5337016 | NTNCWS | Vancouver | 21 | Clark County |
| Columbia Springs Estates | WA5304298 | CWS | Tonasket | 54 | Lincoln County |
| Columbia View Water System | WA5314176 | CWS | West Richland | 500 | Walla Walla County |
| Columbus Park | WA5314185 | CWS | Port Orchard | 241 | Thurston County |
| Colville Sda Church | WA53AB191 | NTNCWS | Springdale | 91 | Stevens County |
| Combined Water System | WA5305795 | CWS | Coupeville | 435 | Island County |
| Common Field Water System | WA53AB738 | CWS | Lopez Island | 36 | San Juan County |
| Community Sewer And Water District | WA5305966 | CWS | Kennewick | 1,200 | Benton County, Franklin County |
| Conagra Foods Lamb Weston Inc-Farm | WA5363913 | CWS | Pasco | 107 | Benton County |
| Concrete Utilities | WA5303950 | CWS | Mt Vernon | 1,234 | Skagit County |
| Congdon Orchards Inc | WA5314540 | NTNCWS | Yakima | 136 | Yakima County |
| Consolidated Irrigation Dist 14 | WA5314650 | CWS | Walla Walla | 1,555 | Walla Walla County |
| Cooks In-Lieu Tfas | 105338113 | NTNCWS | Portland | 70 | Skamania County |
| Cooper Point Estates | WA5302306 | CWS | Olympia | 36 | Thurston County |
| Cooper Point Water Co | WA5314800 | CWS | Shelton | 85 | Thurston County |
| Cooperfield 678 | WA5304459 | CWS | Lacey | 38 | Thurston County |
| Coppermill 520 | WA53AD478 | CWS | Lacey | 62 | Thurston County |
| Corbett Creek | WA5329790 | CWS | Port Orchard | 95 | Stevens County |
| Cornerstone Estates 606 | WA5300133 | CWS | Lacey | 48 | Thurston County |
| Cornerstone Industrial Park | WA5307614 | NTNCWS | Shelton | 30 | Mason County |
| Cornet Bay Heights Water Assn Inc | WA5315020 | CWS | Coupeville | 99 | Island County |
| Cornwall Church Of God | WA5307028 | NTNCWS | Lynden | 92 | Whatcom County |
| Corral Springs Water System | WA5351714 | CWS | Tonasket | 336 | Douglas County |
| Cosmopolis Water Department | WA5315050 | CWS | Raymond | 1,812 | Grays Harbor County |
| Cottage Farms | WA53AC914 | CWS | Cle Elum | 30 | Kittitas County |
| Cottonwood Glen Water Assn | WA5315112 | CWS | Yakima | 65 | Walla Walla County |
| Cougar Campers | WA53AB548 | CWS | Cle Elum | 44 | Grant County |
| Cougar Crest | WA5315130 | CWS | Port Orchard | 290 | Cowlitz County |
| Cougar Mountain | WA5315150 | CWS | Port Orchard | 220 | Thurston County |
| Cougar Ridge | WA5324006 | CWS | Shelton | 216 | Thurston County |
| Coulee City Town Of | WA5315300 | CWS | Coulee City | 944 | Grant County |
| Coulee Dam Water Dept | WA5315400 | CWS | Coulee Dam | 1,454 | Douglas County, Okanogan County |
| Coulee Flats Dairy | WA53AB974 | NTNCWS | Yakima | 83 | Franklin County |
| Country Club 679 | WA5315503 | CWS | Lacey | 175 | Thurston County |
| Country Club Estates 521 | WA5315502 | CWS | Lacey | 113 | Thurston County |
| Country Club Estates Hoa | WA5315501 | CWS | Yakima | 70 | Yakima County |
| Country Club Estates Water System | WA5318189 | CWS | Moses Lake | 186 | Grant County |
| Country Corner Mobile Home Park | WA5306456 | CWS | Gig Harbor | 95 | Grant County, Lewis County |
| Country Estates | WA5315505 | CWS | Port Orchard | 150 | Grays Harbor County, Lewis County |
| Country Haven Water Assoc | WA5315510 | CWS | Bellingham | 50 | Whatcom County |
| Country Lane Community Water | WA5315485 | CWS | Port Orchard | 53 | Thurston County |
| Country Lane East | WA5315523 | CWS | Moses Lake | 27 | Adams County |
| Country Manor Mobile Home Park | WA5315521 | CWS | Port Orchard | 450 | Clark County |
| Country Meadows | WA5300675 | CWS | Port Orchard | 90 | Kitsap County |
| Country Meadows East Water Sys #2 | WA5362021 | CWS | Port Orchard | 40 | Pierce County |
| Country Mercantile | WA5351851 | NTNCWS | Pasco | 398 | Franklin County |
| Country Mobile Estates | WA5315514 | CWS | Yakima | 180 | Yakima County |
| Country Place Mobile Home Park | WA5312003 | CWS | Coupeville | 200 | Island County |
| Country Squire Mobile Manor | WA5315515 | CWS | Yakima | 131 | Yakima County |
| Country Villa Mobile Park | WA5315518 | CWS | Colville | 162 | Stevens County |
| Country/Eldorado Water System | WA5315522 | CWS | Puyallup | 915 | Pierce County |
| Countrywood Estates 680 | WA5308393 | CWS | Lacey | 488 | Thurston County |
| Covington 212 | WA5302050 | CWS | Lacey | 40 | Thurston County |
| Cowiche Growers Inc | WA5356398 | NTNCWS | Yakima | 177 | Yakima County |
| Cowiche Water Association | WA5304316 | CWS | Yakima | 48 | Yakima County |
| Cowlitz Falls Road Project | WA5302877 | NTNCWS | Morton | 30 | Lewis County |
| Cowlitz Indian Tribal Housing | WA5325244 | CWS | Mossyrock | 52 | Lewis County |
| Coxville Water Assn #1 | WA5302777 | CWS | Benton City | 26 | Benton County |
| Coyle | WA5336711 | CWS | Port Townsend | 329 | Jefferson County |
| Crane Ranch | WA5315818 | CWS | Tonasket | 329 | Douglas County |
| Creekside Apartments | WA5345164 | CWS | Black Diamond | 100 | Pierce County |
| Creekside Camping | WA5328977 | CWS | Mt Vernon | 31 | Skagit County |
| Creekside Meadows Division Ii | WA5304863 | CWS | Tacoma | 85 | Thurston County |
| Crescent Acres Water Association | WA5315930 | CWS | Coupeville | 64 | Island County |
| Crescent Bar System | WA5315950 | CWS | Ephrata | 1,108 | Grant County |
| Crescent Park | WA5315999 | CWS | Tacoma | 53 | Thurston County |
| Crescent Park 355 | WA5316000 | CWS | Lacey | 550 | Pierce County |
| Crescent Valley #333 | WA5337654 | CWS | Tacoma | 91 | Pierce County |
| Crescent View Condominium Owners | WA5303129 | CWS | Quincy | 243 | Grant County |
| Creston Public Water | WA5316150 | CWS | Waverly | 348 | Lincoln County |
| Crestview Mobile Manor | WA5316215 | CWS | Puyallup | 123 | Pierce County |
| Crestview Tracts #3 | WA5316231 | CWS | Auburn | 77 | King County |
| Crestview West Water System | WA5316232 | CWS | Kent | 147 | King County |
| Cristalina | WA5303014 | CWS | Tacoma | 225 | King County |
| Cro Farms Inc | WA5314174 | CWS | Rock Island | 297 | Douglas County |
| Crocker Creek 663 | WA5338261 | CWS | Lacey | 60 | Pierce County |
| Crockett Lake Water District | WA5316256 | CWS | Freeland | 325 | Island County |
| Crosswoods Water System | WA5316274 | CWS | Coupeville | 420 | Island County |
| Crowder Road 213 | WA5316277 | CWS | Lacey | 54 | Thurston County |
| Crumbacher Estates Water System | WA5313916 | CWS | Tonasket | 111 | Okanogan County |
| Crystal Creek | WA5347421 | CWS | Silverdale | 123 | Kitsap County |
| Crystal Lake Inc | WA5316390 | CWS | Woodinville | 170 | Snohomish County |
| Crystal River Ranch Assoc | WA5316480 | CWS | Greenwater | 302 | Pierce County |
| Crystal Springs | WA5330049 | CWS | Tacoma | 37 | Thurston County |
| Crystal Village I-Ii-Iii | WA5316575 | CWS | Enumclaw | 146 | Pierce County |
| Cumberland Coop Water System | WA5316650 | CWS | Port Orchard | 210 | King County |
| Curlew Conservation Center | WA53FS165 | CWS | Curlew | 349 | Ferry County |
| Curlew Kai Homeowner Water System | WA5310581 | CWS | Republic | 133 | Ferry County |
| Curlew Water & Sewer District | WA5316900 | CWS | Republic | 316 | Ferry County |
| Curries Landing | WA5303463 | CWS | Tacoma | 61 | Mason County |
| Cusick Town Of | WA5317000 | CWS | Cusick | 672 | Pend Oreille County |
| Custer Water Association | WA5317050 | CWS | Custer | 365 | Whatcom County |
| Cuyamaca | 105300089 | CWS | Olympia | 375 | Thurston County |
| Cuyamaca Village | WA5317100 | CWS | Tacoma | 106 | Thurston County |
| Cypress Country Estates | WA5315461 | CWS | Othello | 253 | Franklin County |
| Dakota Heights Water System | WA53AC681 | CWS | Cle Elum | 29 | Kittitas County |
| Dallesport Domestic Water Sharers | WA5315077 | CWS | Dallesport | 32 | Klickitat County |
| Dallesport Industrial Park | WA5300238 | NTNCWS | Goldendale | 495 | Klickitat County |
| Dallesport Mobile Home Park | WA5308136 | CWS | Yakima | 101 | Klickitat County |
| Dallesport Water District | WA5317715 | CWS | Dallesport | 598 | Klickitat County |
| Damman School | WA5317765 | NTNCWS | Ellensburg | 45 | Kittitas County |
| Dana Passage 523 | WA5317794 | CWS | Lacey | 210 | Thurston County |
| Danner Corp | WA5306806 | NTNCWS | Auburn | 50 | King County |
| Darrington Town Of | WA5317950 | CWS | Darrington | 2,246 | Snohomish County |
| Darrington Water Association | WA5317945 | CWS | Darrington | 42 | Snohomish County |
| Dashmesh Petroleum | WA5337071 | NTNCWS | Napavine | 284 | Lewis County |
| Davenport Water Division | WA5318100 | CWS | Davenport | 1,750 | Lincoln County |
| Davis Landing Water System | WA5318140 | CWS | Coupeville | 74 | Island County |
| Davis Terrace Water Assn | WA5318150 | CWS | Woodland | 222 | Cowlitz County |
| Dawn Lee Courts | WA5318188 | CWS | Cashmere | 100 | Chelan County |
| Dawnbreaker Water Association | WA5312154 | CWS | Port Orchard | 168 | King County |
| Dayton Trails | WA5302715 | CWS | Shelton | 148 | Mason County |
| Dayton Water Department | WA5318250 | CWS | Dayton | 3,374 | Columbia County |
| Deception Park View | WA5318305 | CWS | Port Orchard | 180 | Island County |
| Dechaux Mutual Water | WA5318350 | CWS | Port Orchard | 40 | Pierce County |
| Deep Creek Ranchettes | WA5339003 | CWS | Port Orchard | 200 | Spokane County |
| Deer Creek Water Assn/Guide South | WA53AB912 | CWS | Bellingham | 251 | Whatcom County |
| Deer Creek Water Assoc. | WA5318418 | CWS | Lynden | 2,000 | Whatcom County |
| Deer Lake Estates | WA5318440 | CWS | Coupeville | 55 | Island County |
| Deer Lake Haven Inc | WA5318450 | CWS | Freeland | 90 | Island County |
| Deer Meadows Water Company Inc | WA5301852 | CWS | Davenport | 268 | Lincoln County |
| Del Bay | WA5318575 | CWS | Freeland | 50 | Island County |
| Del Mar Community Service | WA5318580 | CWS | Anacortes | 657 | Skagit County |
| Delia Jimicum Water District | 105300135 | CWS | Tulalip | 42 | |
| Delphi | WA5318643 | CWS | Shelton | 381 | Thurston County |
| Delphi Daubel | WA5318650 | CWS | Olympia | 29 | Thurston County |
| Delphi Mobile Home Park | WA5335092 | CWS | Port Orchard | 85 | Thurston County |
| Delta Long Lk Acre Tracts | WA5310340 | CWS | Tacoma | 53 | Kitsap County |
| Delta Water Association | WA5318750 | CWS | Lynden | 450 | Whatcom County |
| Deming Water Assoc. | WA5318800 | CWS | Deming | 501 | Whatcom County |
| Derby Downs | WA5307009 | CWS | Port Orchard | 36 | Kitsap County |
| Derbyshire Scenic Acres | WA5319000 | CWS | Port Orchard | 156 | King County |
| Deschutes Village 683 | WA5319035 | CWS | Lacey | 140 | Thurston County |
| Desert Aire Owner Assn | WA5319056 | CWS | Desert Aire | 2,856 | Grant County |
| Desert Canyon Domestic Water System | WA5302498 | CWS | Orondo | 292 | Douglas County |
| Desert Hills | WA53AC131 | CWS | Moses Lake | 30 | Grant County |
| Desert Villa | WA5319068 | CWS | Yakima | 100 | Grant County |
| Detroit Water Service Assn | WA5319095 | CWS | Port Orchard | 57 | Mason County |
| Devries Road Community Assn | WA5315948 | CWS | Coupeville | 76 | Island County |
| Dexter By The Sea | WA5319175 | CWS | Raymond | 96 | Pacific County |
| Deytona | WA5319184 | CWS | Port Angeles | 50 | Clallam County |
| Dh Feeders - Agri Beef | WA53AC463 | NTNCWS | Pasco | 40 | Franklin County |
| Diablo Wtr Sys-Seattle City Light | WA5319200 | CWS | Mt Vernon | 53 | Whatcom County |
| Diamond Lake Water & Sewer District | WA5319207 | CWS | Newport | 1,299 | Pend Oreille County |
| Diamond Point | WA5319210 | CWS | Freeland | 810 | Clallam County |
| Diamond Point Water System | WA5306536 | CWS | Cle Elum | 110 | Grant County |
| Diamond Springs Water Association | WA5319215 | CWS | Port Orchard | 138 | King County |
| Discovery Bay Leaseholders | WA5314071 | CWS | Sequim | 123 | Jefferson County |
| Discovery Bay Village | WA5319430 | CWS | Sequim | 191 | Jefferson County |
| Discovery Homes #1 | WA5303679 | NTNCWS | Shelton | 76 | Mason County |
| Dixie Water Association | WA5319480 | CWS | Walla Walla | 240 | Walla Walla County |
| Dobler John D Water System | WA5371605 | CWS | Port Orchard | 128 | Pierce County |
| Doc Stewart | WA53AD731 | CWS | Yakima | 100 | Grant County |
| Dockton Water Association | WA5319550 | CWS | Vashon | 992 | King County |
| Doe Bay Water Users Assoc | WA5319600 | CWS | Eastsound | 442 | San Juan County |
| Dominion View Water Assn | WA5323379 | CWS | Chewelah | 37 | Stevens County |
| Double L Mobile Home Park | WA5319890 | CWS | Lynden | 58 | Whatcom County |
| Double View Community Club | WA5319900 | CWS | Mt Vernon | 47 | Island County |
| Doyle Water Association | WA5319155 | CWS | Oak Harbor | 36 | Island County |
| Driftwood Acres Maintenance Corp | WA5319943 | CWS | Cle Elum | 114 | Kittitas County |
| Driftwood Cove | WA5319945 | CWS | Poulsbo | 175 | Kitsap County |
| Driftwood Heights #2 Community Assn | WA5322871 | CWS | Arlington | 40 | Island County |
| Driftwood Heights Association | WA5319948 | CWS | Coupeville | 298 | Island County |
| Driftwood Point Water System | WA5302667 | CWS | Gig Harbor | 143 | Pierce County |
| Driftwood Shores Water System Inc | WA5320000 | CWS | Mt Vernon | 222 | Island County |
| Driftwood Valley Assoc (Dva) | WA5320003 | CWS | Tacoma | 151 | Thurston County |
| Druse Water Association | WA5320030 | CWS | Yakima | 32 | Yakima County |
| Dry Creek Water Association | WA5320050 | CWS | Port Angeles | 3,030 | Clallam County |
| Dry Sort Domestic | WA5306731 | NTNCWS | Port Orchard | 80 | Mason County |
| Dryden Orchard | WA5320095 | CWS | Dryden | 26 | Chelan County |
| Duane Jenks | WA53AD239 | NTNCWS | Yakima | 35 | Grant County |
| Duck Lake Water Association | WA5320200 | CWS | Okanogan | 635 | Okanogan County |
| Duggan Falls | WA5303754 | CWS | Port Orchard | 100 | Skamania County |
| Dugualla Community Inc | WA5320250 | CWS | Oak Harbor | 459 | Island County |
| Dunbar Cove Development Assoc. | WA5320265 | CWS | Port Orchard | 69 | Pierce County |
| Dungeness Bay Plat | WA5320300 | CWS | Sequim | 461 | Clallam County |
| Dungeness Beach | WA5320350 | CWS | Sequim | 181 | Clallam County |
| Dungeness Heights | WA5320425 | CWS | Yelm | 558 | Clallam County |
| E.L.C. Water System | WA5302051 | CWS | Eastsound | 36 | San Juan County |
| Eagle Cove Water Association | WA5320803 | CWS | Friday Harbor | 65 | San Juan County |
| Eagle Estates | WA5302348 | CWS | Tacoma | 53 | Thurston County |
| Eagle Ridge | WA5324731 | CWS | Arlington | 250 | Snohomish County |
| Eagle Valley Water System | WA5302217 | CWS | Coupeville | 135 | Skagit County |
| Eaglecrest Water & Road Association | WA5326091 | CWS | Coupeville | 28 | Island County |
| Eagles Landing Water System | WA5308120 | NTNCWS | Mt Vernon | 37 | Island County |
| East Crystal Lake Estates Community | WA5330164 | CWS | Mt Vernon | 38 | Snohomish County |
| East Gig Harbor Water District | WA5331050 | CWS | Gig Harbor | 410 | Pierce County |
| East Monitor Water Assn | WA5321200 | CWS | Wenatchee | 36 | Chelan County |
| East Olympia 684 | WA5304601 | CWS | Lacey | 230 | Thurston County |
| East Olympia Elementary School | WA5358814 | NTNCWS | Tumwater | 593 | Thurston County |
| East Ridge Park | WA5321450 | CWS | Yakima | 150 | Yakima County |
| Eastgate | WA5322030 | CWS | Coupeville | 76 | Island County |
| Easton Water District | WA5342700 | CWS | Cle Elum | 362 | Kittitas County, Pierce County |
| Eaton Park Subdivision | WA5322285 | CWS | Kennewick | 70 | Benton County, Franklin County |
| Echo Glen Childrens Center | WA5322330 | CWS | Snoqualmie | 430 | King County |
| Echo Glen Water System | WA5327510 | CWS | Silverdale | 105 | King County |
| Edelweiss Maintenance Commission | WA5322340 | CWS | Winthrop | 95 | Okanogan County |
| Edgehill Water Assn | WA5322400 | CWS | Bonney Lake | 109 | King County |
| Edgewater | WA5322418 | CWS | Yakima | 30 | Yakima County |
| Edgewater Beach Water Co | WA5322416 | CWS | Shelton | 78 | Thurston County |
| Edgewater Mobile Estates | WA5322421 | CWS | Port Orchard | 70 | Cowlitz County |
| Edwall Water Assn | WA5322550 | CWS | Edwall | 170 | Lincoln County |
| Edwin Markham | WA53AD282 | NTNCWS | Pasco | 216 | Franklin County |
| Eggimann 664 | WA5322585 | CWS | Lacey | 100 | Pierce County |
| El Camano Community Club | WA5322593 | CWS | Mt Vernon | 49 | Island County |
| Elbe Water & Sewer District | WA5322650 | CWS | Elbe | 60 | Pierce County |
| Elderwood Water Association | WA5322690 | CWS | Port Orchard | 52 | King County |
| Eldorado Hills | WA5322750 | CWS | Poulsbo | 383 | Kitsap County |
| Electric City City Of | WA5322850 | CWS | Electric City | 1,812 | Grant County |
| Elgerwood Maintenance Association | WA5309131 | CWS | Coupeville | 112 | Island County |
| Elk Heights 247 | WA5352614 | CWS | Lacey | 98 | Pierce County |
| Elkhorn Water District | WA5300489 | CWS | Orting | 41 | Pierce County |
| Elm Tree Water & Sewer Assn | WA5323128 | CWS | Tonasket | 38 | Stevens County |
| Elma Evergreen Village | WA5324155 | CWS | Shelton | 29 | Grays Harbor County |
| Elmer City Water System | WA5323120 | CWS | Elmer City | 368 | Okanogan County |
| Elmwood Mobile Manor | WA5323145 | CWS | Port Orchard | 66 | Pierce County |
| Eloika Pines Llc | WA5323180 | CWS | Port Orchard | 87 | Spokane County |
| Eltopia Water Association | WA5323240 | CWS | Eltopia | 100 | Franklin County |
| Elwha Heights | 105311107 | CWS | Port Angeles | 216 | Clallam County |
| Elwha Place Homeowners Assn | WA5301581 | CWS | Port Angeles | 61 | Clallam County |
| Emanuel Heights Water System | WA5326916 | CWS | Brewster | 60 | Okanogan County |
| Emerald Heights | WA5323290 | CWS | Port Orchard | 251 | Kitsap County |
| Enchanted Firs Mobile Estates | WA5323380 | CWS | Allyn | 120 | Pierce County |
| Endicott Water Dept | WA5323400 | CWS | Waverly | 488 | Whitman County |
| Energy Dept Of/100K | WA5300177 | NTNCWS | Richland, Wa | 235 | Benton County |
| Energy Dept Of/300 Area | WA5341840 | NTNCWS | Richland | 600 | Benton County |
| Energy Dept Of/400 Area | WA5341947 | NTNCWS | Richland | 25 | Benton County |
| Enterprise Estates Water Assoc. | WA5323480 | CWS | Ferndale | 184 | Whatcom County |
| Enterprise Terrace Water Assn. | WA5323485 | CWS | Ferndale | 95 | Whatcom County |
| Entiat City Of | WA5323500 | CWS | Entiat | 1,730 | Chelan County |
| Erickson Lake Tracts | WA5354572 | CWS | Port Orchard | 25 | Mason County |
| Erland Point Water Co | WA5323850 | CWS | Silverdale | 2,909 | Kitsap County |
| Estates At Livingston Mtn | WA5300794 | CWS | Woodland | 33 | Clark County |
| Estates Inc | WA5308166 | CWS | Sequim | 1,043 | Clallam County |
| Evaline School | WA5323953 | NTNCWS | Napavine | 60 | Lewis County |
| Evans Water System | WA5323960 | CWS | Colville | 47 | Ferry County, Stevens County |
| Evergreen Clallam County Pud 1 | WA5324181 | CWS | Carlsborg | 1,694 | Clallam County |
| Evergreen Elementary School | WA5324774 | NTNCWS | Gig Harbor | 310 | Pierce County |
| Evergreen Mobile Homeowners Co-Op | WA5324154 | CWS | Shelton | 140 | Mason County |
| Evergreen Mobile Park & Sales | WA5324151 | CWS | Lynden | 180 | Whatcom County |
| Evergreen Retreat Mhp | WA5324164 | CWS | Santa Rosa | 39 | Whatcom County |
| Evergreen School District #205 | WA5324162 | NTNCWS | Gifford | 25 | Stevens County |
| Evergreen Shores | WA5324163 | CWS | Tacoma | 1,329 | Thurston County |
| Evergreen Sky Ranch Community Wtr | WA5324165 | CWS | Auburn | 43 | King County |
| Evergreen Valley | WA5302150 | CWS | Cle Elum | 152 | Kittitas County |
| Evergreen Valley View Water System | WA5324170 | CWS | Oak Harbor | 40 | Island County |
| Evergreen Vista 308 | WA5331881 | CWS | Lacey | 50 | Pierce County |
| Evergreen Water & Improvement Assn | WA5324180 | CWS | Port Orchard | 150 | King County |
| Everson Water Assoc | WA5324195 | CWS | Lynden | 130 | Whatcom County |
| Fairchild Community Llc | WA5324355 | CWS | Port Orchard | 98 | Spokane County |
| Fairfield Mhp | WA5302601 | CWS | Lynden | 66 | Whatcom County |
| Fairfield Town Of | WA5324450 | CWS | Tekoa | 643 | Spokane County |
| Fairview Domestic Water Assn | WA5324500 | CWS | Othello | 89 | Adams County |
| Fairway Estates Inc | WA5324524 | CWS | Coupeville | 100 | Island County |
| Fairway Number Three Water | WA5324528 | CWS | Friday Harbor | 39 | San Juan County |
| Fairwind Mobile Home Park | WA5344052 | CWS | Port Orchard | 45 | Thurston County |
| Fall City Water Dist. #127 | WA5324550 | CWS | Fall City | 2,987 | King County |
| Fall City Water Dist. (Plum Creek) | WA5364294 | CWS | Fall City | 59 | King County |
| Fall City Water Dist. (Ruth) | WA5302006 | CWS | Fall City | 49 | King County |
| Fall City Water Dist.(Spring Hill) | WA5383310 | CWS | Fall City | 57 | King County |
| Faranda Water Associaton | WA5324643 | CWS | Oak Harbor | 28 | Island County |
| Farmington Water Dept | WA5324700 | CWS | Farmington | 165 | Whitman County |
| Farrell L. E. | WA5324707 | CWS | Port Orchard | 32 | King County |
| Fawn Lake Maintenance Comm | WA5324713 | CWS | Shelton | 1,044 | Mason County |
| Fern Bluff Estates | WA5301736 | CWS | Monroe | 30 | Snohomish County |
| Ferndale Estates Llc | WA5324840 | CWS | Ferndale | 85 | Whatcom County |
| Field Of Dreams | WA5308066 | CWS | Port Orchard | 247 | Thurston County |
| Fields Water Association | WA5352590 | CWS | Mt Vernon | 60 | Island County |
| Fieldstone Memory Care Bainbridge | WA5354200 | CWS | Lake Tapps | 175 | Kitsap County |
| Finisterre Heights Water System | WA5302145 | CWS | Mt Vernon | 193 | Island County |
| Finley Elementary School (New) | WA5302558 | NTNCWS | Cle Elum | 450 | Benton County |
| Finley School District #53 | WA5325115 | NTNCWS | Cle Elum | 990 | Benton County |
| Fir Grove Mobile Park | WA5325137 | CWS | Coupeville | 65 | Island County |
| Fircrest Community Water System | WA5324529 | CWS | Coupeville | 150 | Island County |
| Firewell Enterprises | WA5307130 | NTNCWS | Napavine | 40 | Lewis County |
| First Baptist Church Of Tenino | WA5307255 | NTNCWS | Port Orchard | 140 | Thurston County |
| First Potholes Water Users Assn | WA5325250 | CWS | Moses Lake | 90 | Grant County |
| Firstfruits Farms | WA5308690 | CWS | Yakima | 68 | Walla Walla County |
| Fisherman Bay Water Association | WA5325547 | CWS | Lopez Island | 1,195 | San Juan County |
| Flauras Acres Propertyowner | WA5325600 | CWS | Sequim | 150 | Clallam County |
| Flemings Platt Water Association | WA5325610 | CWS | Lynden | 84 | Whatcom County |
| Floating Bear | WA5365153 | NTNCWS | Shelton | 37 | Thurston County |
| Flying Carpet Mobile Estates | WA5325722 | CWS | Napavine | 174 | Thurston County |
| Flying H Youth Ranch | WA5325726 | NTNCWS | Naches | 44 | Yakima County |
| Fobes Water District | WA5325750 | CWS | Snohomish | 156 | Snohomish County |
| Foothills Water Association | WA53AA296 | CWS | Port Orchard | 271 | King County |
| Ford-Newhouse Lane | 105338100 | CWS | Wellpinit | 160 | Stevens County |
| Fordair Water Co-Op Inc | WA5325800 | CWS | Quincy | 43 | Grant County |
| Fordyce Water Assn | WA5305182 | CWS | Husum | 302 | Klickitat County |
| Forest Beach Water System | WA5325900 | CWS | Gig Harbor | 204 | Pierce County |
| Forest Glen 762 | WA5301712 | CWS | Lacey | 62 | Pierce County |
| Forest Grove Hills | WA5325932 | CWS | Port Orchard | 50 | King County |
| Forest Grove Mobile Home Park | WA5325934 | CWS | Arlington | 51 | Snohomish County |
| Forest Hills Park Community | WA5309871 | CWS | Oak Harbor | 54 | Island County |
| Forest Hills Water System | WA5312613 | CWS | Gig Harbor | 140 | Pierce County |
| Forest Park | WA5307167 | CWS | Tacoma | 127 | Thurston County |
| Forest Park Water System | WA5325943 | CWS | Gig Harbor | 120 | Pierce County |
| Forest Ridge | WA5325949 | CWS | Sequim | 65 | Clallam County |
| Forestview Senior Community Llc | WA5305811 | CWS | Port Orchard | 92 | Grays Harbor County |
| Fort Knox Mobile Home Park | WA5359576 | CWS | Coupeville | 79 | Island County |
| Fort Simcoe Job Corps Ctr | 105300127 | CWS | White Swan | 230 | Yakima County |
| Foss Road | WA5363918 | CWS | Tacoma | 119 | Kitsap County |
| Four Corners | WA5315296 | CWS | Tacoma | 77 | Pierce County |
| Four Creeks Ranch Water System | WA5322740 | CWS | Issaquah | 150 | King County |
| Four Lakes | WA5326195 | CWS | Lake Forest Park | 212 | King County |
| Four Lakes Water District 10 | WA5326200 | CWS | Four Lakes | 433 | Spokane County |
| Four Seasons Park | WA5300302 | CWS | Sequim | 225 | Clallam County |
| Fourth Of July Creek Estates | WA5331989 | CWS | Curlew | 29 | Ferry County |
| Fox Island Mutual Water Assoc | WA5326300 | CWS | Fox Island | 3,255 | Pierce County |
| Foxhall | WA5310991 | CWS | Tacoma | 549 | Thurston County |
| Fpl Energy Vansycle | WA5300595 | NTNCWS | College Place | 34 | Walla Walla County |
| Fragaria Landing | WA5326651 | CWS | Port Orchard | 235 | Kitsap County |
| Freeland Water And Sewer District | WA5326450 | CWS | Freeland | 1,264 | Island County |
| Freeman School Dist #358 | WA5326460 | NTNCWS | Rockford | 900 | Spokane County |
| Frenchman Hills Vineyard | WA53AD417 | NTNCWS | Moses Lake | 56 | Grant County |
| Friar Creek Water System | WA5316351 | CWS | Monroe | 135 | Snohomish County |
| Frog Pond | WA5326627 | CWS | Pouslbo | 1,229 | Kitsap County |
| Frost Road Park | WA5326647 | CWS | Winlock | 65 | Lewis County |
| Frostad Farms Water Assn | WA5326648 | CWS | Oak Harbor | 25 | Island County |
| Gala Pines Water. | WA5327060 | CWS | Poulsbo | 130 | Kitsap County |
| Game Farm Estates | WA53AB325 | CWS | Cle Elum | 81 | Kittitas County |
| Garden Court Mutual | WA5318221 | CWS | Port Orchard | 54 | Pierce County |
| Gardiner Lud 1 | WA5307877 | CWS | Port Townsend | 379 | Jefferson County |
| Garfield Water Department | WA5327200 | CWS | Tekoa | 694 | Whitman County |
| Gatewood Mobile Manor | WA5327236 | CWS | Port Orchard | 46 | Kitsap County |
| Gays Water District Association | WA5327270 | CWS | Arlington | 81 | Snohomish County |
| Gee Cee S Truckstop | WA5337247 | NTNCWS | Castle Rock | 646 | Lewis County |
| General Dynamics - Ots | WA53AB976 | NTNCWS | Moses Lake | 38 | Grant County |
| George City Of | WA5327395 | CWS | George | 1,035 | Grant County |
| George Lane | 105314113 | CWS | Suquamish | 75 | |
| Georgetown Water Association | WA5312636 | CWS | Coupeville | 32 | Island County |
| Georgeville | 105300024 | CWS | Toppenish | 70 | Klickitat County |
| Georgia Manor Water Assoc | WA5327450 | CWS | Lynden | 81 | Whatcom County |
| Giffords 685 | WA5300886 | CWS | Lacey | 90 | Thurston County |
| Gig Harbor Academy | WA5364920 | NTNCWS | Port Orchard | 168 | Pierce County |
| Glacier Springs Water Assn | WA5327750 | CWS | Trout Lake | 992 | Klickitat County |
| Glacier Springs Water System | WA5327755 | CWS | Lynden | 88 | Whatcom County |
| Glacier Vista 665 | WA5307749 | CWS | Lacey | 100 | Pierce County |
| Glacier Water District | WA5395915 | CWS | Glacier | 2,383 | Whatcom County |
| Gleed Mobile Estates | WA5327828 | CWS | Yakima | 76 | Yakima County |
| Glen Alder 522 | WA5327900 | CWS | Lacey | 31 | Thurston County |
| Glen Cove Water Association | WA5327950 | CWS | Lynden | 39 | Whatcom County |
| Glen Cove Water Inc. | WA5303606 | CWS | Gig Harbor | 223 | Pierce County |
| Glenhaven Lakes Club | WA5328050 | CWS | Sedro Woolley | 1,780 | Whatcom County |
| Glenwood Farms 1 East | WA5336241 | CWS | Tacoma | 87 | Kitsap County |
| Glenwood Farms 2 West | WA5336233 | CWS | Tacoma | 48 | Kitsap County |
| Glenwood Station | WA5300561 | CWS | Tacoma | 144 | Kitsap County |
| Glenwood Water System | WA5328220 | CWS | Goldendale | 629 | Klickitat County |
| Gmp Orchards Llc - Harbo | WA53AD606 | CWS | Yakima | 96 | Benton County |
| Gold Beach Water Company | WA5328350 | CWS | Vashon | 390 | King County |
| Golden Meadow | WA53AA608 | CWS | Tacoma | 90 | Pierce County |
| Golden Oak | WA5328392 | CWS | Port Orchard | 57 | Thurston County |
| Golden Plains Mhp #1 | WA5389060 | CWS | Moses Lake | 360 | Adams County |
| Golden Valley Water Assn | WA5328400 | CWS | Quincy | 138 | Grant County |
| Goldens Mobile Home Park | WA5328385 | CWS | Port Orchard | 23 | Kitsap County |
| Good Neighbors Water Assn | WA5376468 | CWS | Kennewick | 40 | Benton County |
| Goodnight Water System | WA5303414 | CWS | Kennewick | 47 | Benton County, Walla Walla County |
| Goose Gap Water Association | WA5303404 | CWS | Richland | 25 | Benton County, Franklin County |
| Goosehaven | WA5327496 | CWS | Newport | 75 | Pend Oreille County |
| Goss Lake Park Community | WA5328575 | CWS | Coupeville | 285 | Island County |
| Goss Lakeridge Acres Association | WA5322070 | CWS | Freeland | 27 | Island County |
| Graham Hill Mutual Water Co Inc | WA5328650 | CWS | Graham | 1,440 | Pierce County |
| Graham Place | WA5325341 | CWS | Port Orchard | 41 | Kitsap County |
| Grand Coulee Water Dept City Of | WA5328700 | CWS | Grand Coulee | 1,428 | Grant County |
| Grand Mound | WA5307158 | CWS | Olympia | 3,764 | Thurston County |
| Grand Mound Motel | WA5307989 | CWS | Napavine | 36 | Thurston County |
| Grandview Beach Water Assoc Inc | WA5328950 | CWS | Blain | 28 | Whatcom County |
| Grandview Condominiums | WA53AE050 | CWS | Port Orchard | 679 | King County |
| Grandview Farms Pasco - Dodd Rd | WA5309701 | NTNCWS | Kennewick | 32 | Walla Walla County |
| Grandview Valley Estates | WA5328967 | CWS | Rochester | 138 | Thurston County |
| Grandview-Northgate Industrial Park | WA5300638 | NTNCWS | Ferndale | 400 | Whatcom County |
| Granite Glen | WA5329055 | CWS | Cle Elum | 34 | Chelan County |
| Grapeview School | WA5329130 | NTNCWS | Shelton | 257 | Mason County |
| Grasslands Park | WA53AB290 | CWS | Cle Elum | 29 | Kittitas County |
| Grasslands Water System | WA5329172 | CWS | Ellensburg | 264 | Kittitas County |
| Grays Harbor Co Water Dist 1 | WA5329200 | CWS | Raymond | 1,302 | Grays Harbor County, Pacific County |
| Graystone Ws | WA53AD688 | CWS | Pasco | 94 | Franklin County |
| Great Basin Water Burbank | WA5331477 | CWS | Pasco | 656 | Walla Walla County |
| Great Basin Water Kiona | WA5310724 | CWS | Pasco | 520 | Benton County |
| Great Basin Water Sunrise | WA5385630 | CWS | Pasco | 100 | Benton County |
| Great Northern School Dist #312 | WA5329335 | NTNCWS | Springdale | 47 | Spokane County |
| Great Western Mobile Home Park | WA5306772 | CWS | Vancouver | 250 | Clark County |
| Greater Bar Water District | WA5319910 | CWS | Bridgeport | 330 | Douglas County |
| Green Acres - Mattawa | WA53AB860 | NTNCWS | Cle Elum | 267 | Grant County |
| Green Acres Day Care | WA5307559 | NTNCWS | Mt Vernon | 35 | Snohomish County |
| Green Acres Mobile Home Park | WA5329358 | CWS | Sequim | 74 | Clallam County |
| Green Acres Orchard | WA53AB877 | NTNCWS | Mattawa | 308 | Grant County |
| Green Acres Water Association | WA5329655 | CWS | Port Orchard | 44 | King County |
| Green Bluff Water Assn | WA5301483 | CWS | Colbert | 218 | Spokane County |
| Green Bobbie | WA5316527 | NTNCWS | Port Orchard | 80 | King County |
| Green Island Hills Water Assn | WA5300429 | CWS | Mt Vernon | 265 | Island County |
| Green Meadows Subdivision | WA5329450 | CWS | Yakima | 32 | Yakima County |
| Green Mountain Acres | WA5329594 | CWS | Poulsbo | 110 | Kitsap County |
| Green Mountain Mill Weyerhaeuser | WA5329460 | NTNCWS | Castle Rock | 145 | Cowlitz County |
| Green Mountain Mobile Ranch | WA5353991 | CWS | Auburn | 80 | Clark County |
| Green Mountain School | WA5329465 | NTNCWS | Woodland | 200 | Clark County |
| Green Tank Irr District 11 | WA5329550 | CWS | Walla Walla | 553 | Walla Walla County |
| Green Valley Estates Water Assn | WA5329597 | CWS | Yakima | 53 | Benton County, Yakima County |
| Green Velvet Water System | WA5329615 | CWS | Snohomish | 26 | Snohomish County |
| Greenbank Estates Water System | WA5329710 | CWS | Freeland | 47 | Island County |
| Greenbriar | WA5329345 | CWS | Tacoma | 37 | Pierce County |
| Greenbrier Rail Services | WA5303287 | NTNCWS | Kennewick | 45 | Benton County |
| Greenwater Meadows Landowners Assn | WA5329600 | CWS | Sultan | 122 | Snohomish County |
| Greenwood Estates | WA5329810 | CWS | Tacoma | 61 | Pierce County |
| Greenwood Mobile Home Park | WA5329816 | CWS | Westport | 350 | Grays Harbor County |
| Greenwood Park | WA5329820 | CWS | Port Orchard | 75 | Pierce County |
| Gresham Water | WA5331566 | CWS | Poulsbo | 66 | Jefferson County, Kitsap County |
| Griffin School | WA5329887 | NTNCWS | Port Orchard | 672 | Thurston County |
| Grotto Water Association | WA5330050 | CWS | Skykomish | 36 | King County |
| Grove Terrace Mhp Two Llc | WA5308520 | CWS | Moses Lake | 220 | Grant County |
| Guide Meridian Water Association | WA5330200 | CWS | Lynden | 258 | Whatcom County |
| Gunderson Water Works | WA5330235 | CWS | Napavine | 53 | Lewis County |
| Hamilton Al | WA5330705 | NTNCWS | Napavine | 1,807 | Lewis County |
| Hamilton Water Department | WA5330700 | CWS | Maple Falls | 540 | Skagit County |
| Hamma Ridge | WA5305867 | CWS | Shelton | 63 | Mason County |
| Hampton Water Association | WA5330800 | CWS | Lynden | 54 | Whatcom County |
| Hangman Hills Water Dist 15 | WA5330848 | CWS | Spokane | 827 | Spokane County |
| Hannah Heights #2 Water Users Assn | WA5325264 | CWS | Friday Harbor | 44 | San Juan County |
| Hannah Heights Owners Association | WA5330850 | CWS | Friday Harbor | 66 | San Juan County |
| Hanson Harbor Homeowners Assn | WA5319928 | CWS | Tonasket | 220 | Lincoln County |
| Happy Hill Community Club | WA5330955 | CWS | Port Orchard | 69 | Snohomish County |
| Happy Valley Estates | WA5330975 | CWS | Sequim | 46 | Clallam County |
| Harbor Country Apartments | WA5315314 | CWS | Port Orchard | 410 | Pierce County |
| Harbor Crest | WA5301832 | CWS | Poulsbo | 53 | Kitsap County |
| Harbor Heights | WA5331001 | CWS | Tacoma | 188 | Kitsap County |
| Harbor Hill | WA5331003 | CWS | Freeland | 43 | Island County |
| Harbor Hills Community Water System | WA5333860 | CWS | Freeland | 1,373 | Island County |
| Harbor Mobile Estates | WA5331005 | CWS | Hoquiam | 72 | Grays Harbor County |
| Harbor Montessori Creekside | WA53AB940 | NTNCWS | Port Orchard | 45 | Kitsap County |
| Harbor On Fisherman Bay | WA5331024 | CWS | Lopez Island | 84 | San Juan County |
| Harborland Mobile Park | WA5331075 | CWS | Port Orchard | 75 | Pierce County |
| Harmony Grade School | WA5331355 | NTNCWS | Deming | 325 | Whatcom County |
| Harmony Park Lot Owners | WA5331362 | CWS | Chehalis | 81 | Lewis County |
| Harrah Water System | WA5331400 | CWS | Harrah | 1,304 | Yakima County |
| Harris Custer Estates Water Assn | WA5317035 | CWS | Mt Vernon | 194 | Island County |
| Harrison Well #2 | WA53AB071 | NTNCWS | Yakima | 1,200 | Yakima County |
| Harstene Retreat | WA5331572 | CWS | Shelton | 88 | Mason County |
| Harstine Island Estates Assn | WA5331565 | CWS | Port Orchard | 56 | Mason County |
| Hartley Brent | WA5331497 | NTNCWS | Yakima | 143 | Benton County |
| Hartline Water System | WA5331500 | CWS | Yakima | 249 | Grant County |
| Hartstene Pointe | WA5331569 | CWS | Shelton | 460 | Mason County |
| Hartwood Water System | WA5331575 | CWS | Port Orchard | 95 | Pierce County |
| Hat Island Community Inc | WA5331593 | CWS | Everett | 348 | Snohomish County |
| Hatton Town Of | WA5331600 | CWS | Moses Lake | 105 | Adams County, Franklin County |
| Haven By The Sea | WA5331820 | CWS | Montesano | 308 | Grays Harbor County |
| Hawk Acres 607 | WA5331845 | CWS | Lacey | 328 | Thurston County |
| Hawks Meadow Water System | WA5307956 | CWS | Chelan | 43 | Chelan County |
| Hawley Hills 686 | WA53AB037 | CWS | Lacey | 425 | Thurston County |
| Haynes Acres Division 1 | WA5300792 | CWS | Olympia | 74 | Thurston County |
| Hazel Creek Montessori | WA5306916 | NTNCWS | Port Orchard | 100 | Kitsap County |
| Hazel Dell Mobile Park | WA5331975 | CWS | Woodland | 24 | Cowlitz County |
| Hazelwood Heights | WA5332000 | CWS | Auburn | 85 | King County |
| Heart O The Hills | WA5302632 | CWS | Sequim | 76 | Clallam County |
| Heather Water Works | WA5332114 | CWS | Raymond | 29 | Pacific County |
| Hemmi Road Water Association | WA5332350 | CWS | Everson | 236 | Whatcom County |
| Henderson Bay | WA5377147 | CWS | Tacoma | 61 | Pierce County |
| Henderson Boulevard | WA5308359 | CWS | Tacoma | 418 | Thurston County |
| Henderson Park Development Company | WA5332380 | CWS | Port Orchard | 45 | Pierce County |
| Heritage University Water System | 1053AA941 | NTNCWS | Toppenish | 750 | |
| Heritage University Water System | WA53AA941 | NTNCWS | Toppenish | 750 | Yakima County |
| Heritage West | WA5305898 | CWS | Port Orchard | 70 | Thurston County |
| Hi Lo Homeowners Assn | WA5385203 | CWS | Moses Lake | 87 | Adams County |
| Hi-Color Orchard Farmworker Housing | WA53AC993 | CWS | Wenatchee | 53 | Chelan County, Okanogan County |
| Hi-Point Housing | WA53AD259 | CWS | Pasco | 96 | Franklin County |
| Hiapark | WA5303224 | CWS | Port Orchard | 360 | Mason County |
| Hidden Gardens Homeowners Coop | WA5315483 | CWS | Port Orchard | 66 | Pierce County |
| Hidden Haven Mobile Home Park | WA5332660 | CWS | Belfair | 149 | Mason County |
| Hidden Heights | WA5300944 | CWS | Port Orchard | 35 | Kitsap County |
| Hidden Hills Estates | WA5332642 | CWS | Spokane | 39 | Spokane County |
| Hidden Valley Guest Ranch | WA5332648 | CWS | Cle Elum | 43 | Kittitas County |
| Hide-Away Water Company Inc | WA5366586 | CWS | Coupeville | 240 | Island County |
| High Ridge | WA53AB327 | CWS | Port Orchard | 73 | Cowlitz County |
| High Valley Country Club | WA5332700 | CWS | Packwood | 1,425 | Lewis County |
| High Valley Mobile Home Court | WA5333515 | CWS | Yakima | 142 | Yakima County |
| Highland Estates | WA5332735 | CWS | Union | 110 | Mason County |
| Highland Estates Water System | WA5332736 | CWS | Othello | 53 | Adams County |
| Highland High School | WA5332745 | NTNCWS | Yakima | 500 | Yakima County |
| Highland Meadows | WA5332785 | CWS | Freeland | 70 | Island County |
| Highland Park | WA5332820 | CWS | Shelton | 180 | Mason County |
| Highland Trace Water Co Inc | WA5332840 | CWS | Oak Harbor | 62 | Island County |
| Highland Water District | WA5332850 | CWS | Monroe | 3,121 | Snohomish County |
| Highlands Utility District | WA5332900 | CWS | Shoreline | 275 | King County |
| Hilburn Scott | WA5309931 | NTNCWS | Port Orchard | 68 | Mason County |
| Hillcrest Homestead Tracts Water | WA5333120 | CWS | Coupeville | 29 | Island County |
| Hillcrest Manor | WA5317267 | CWS | Vancouver | 100 | Clark County |
| Hillcrest Mobile Home Park | WA5333140 | CWS | Lakewood | 198 | Pierce County |
| Hillcrest Village Water Co Inc | WA5333150 | CWS | Oak Harbor | 770 | Island County |
| Hillcrest Water Users Assn | WA5333200 | CWS | Moses Lake | 300 | Grant County |
| Hillside Park Addition | WA5333260 | CWS | Yakima | 45 | Yakima County |
| Hilltop Water Owners Association | WA5333364 | CWS | Lummi Island | 137 | Whatcom County |
| Hillview Mobile Community Llc | WA5333366 | CWS | Port Orchard | 118 | Benton County |
| Hillview Water Assn | WA5333365 | CWS | Yakima | 95 | Yakima County |
| Hintzville Acres | WA5310440 | CWS | Tacoma | 170 | Kitsap County |
| Hipma | WA5313701 | CWS | Port Orchard | 39 | Mason County |
| Hiway Trailer Court | WA5335335 | CWS | Port Orchard | 36 | Garfield County, Whitman County |
| Hmc Management Water System | WA5332550 | CWS | Port Orchard | 432 | Pierce County |
| Hogans Corner | WA53AA554 | CWS | Montesano | 1,458 | Grays Harbor County |
| Hogans Water | WA5333625 | CWS | Port Orchard | 28 | Kitsap County |
| Hoh Tribe | 105300011 | CWS | Forks | 120 | Jefferson County |
| Holden Village | WA5333666 | CWS | Chelan | 228 | Chelan County |
| Holiday Acres | WA5333668 | CWS | Shelton | 65 | Thurston County |
| Holiday Beach Water Supply | WA5333669 | CWS | Union | 130 | Mason County |
| Holiday Hideaway Water Co | WA5308236 | CWS | Mt Vernon | 235 | Skagit County |
| Holiday Hills Community Club Inc | WA5333675 | CWS | Port Orchard | 50 | Pierce County |
| Holiday Ranchettes | WA5333677 | CWS | Tacoma | 1,050 | Thurston County |
| Holiday Valley | WA5333678 | CWS | Port Orchard | 180 | Thurston County |
| Hollingsworth Water Assoc Inc | WA5364450 | CWS | Deming | 28 | Whatcom County |
| Holly | WA5333690 | CWS | Port Orchard | 111 | Kitsap County |
| Holly Tides | WA5333695 | CWS | Tacoma | 140 | Pierce County |
| Holmes Harbor Water Co | WA5333870 | CWS | Coupeville | 110 | Island County |
| Home Valley Water District | WA5309188 | CWS | Stevenson | 500 | Skamania County |
| Homestead Acres | WA5333969 | CWS | Tacoma | 109 | Kitsap County |
| Homestead Manufactured Housing | WA5318180 | CWS | Kennewick | 300 | Benton County |
| Homestead Mobile Home Park | WA5301576 | CWS | Tonasket | 105 | Okanogan County |
| Honeybear Growers | WA53AB710 | NTNCWS | Tonasket | 161 | Okanogan County |
| Honeymoon Lake | WA5334005 | CWS | Arlington | 195 | Island County |
| Honeywell Electronic Mfg Llc | WA5314313 | NTNCWS | Republic | 350 | Spokane County |
| Hood Canal | WA5334050 | CWS | Shelton | 368 | Mason County |
| Hood Canal Highlands | WA5334019 | CWS | Port Orchard | 83 | Kitsap County |
| Hood Canal Vista | WA5334040 | CWS | Port Orchard | 45 | Kitsap County |
| Hoodsport | WA5334100 | CWS | Shelton | 1,853 | Mason County |
| Hoot Ridge | WA5323994 | CWS | Port Orchard | 54 | Kitsap County |
| Hope View Water Co | WA5334300 | CWS | Freeland | 53 | Island County |
| Horsehead Bay Water | WA5330878 | CWS | Port Orchard | 65 | Pierce County |
| Horsfall 608 | WA5334505 | CWS | Lacey | 165 | Thurston County |
| Huckleberry Road Water Co | WA5334650 | CWS | Port Orchard | 50 | Thurston County |
| Huffman | WA5300805 | CWS | Port Orchard | 37 | Clallam County |
| Humphrey Head Owners Assoc | WA5334860 | CWS | Lopez Island | 37 | San Juan County |
| Hunt Community (Hunt I&Ii) | WA5300567 | CWS | Port Orchard | 75 | Kitsap County |
| Hunt Community (Hunt Iii) | WA5301591 | CWS | Port Orchard | 30 | Kitsap County |
| Hunters Water District | WA5334889 | CWS | Colville | 290 | Stevens County |
| Hutchinson Irrigation Dist #16 | WA5335100 | CWS | Spokane Valley | 2,209 | Spokane County |
| Hydro Irrigation District No 9 | WA5335275 | CWS | Walla Walla | 260 | Walla Walla County |
| Ice Harbor Dam | WA5309677 | NTNCWS | Pasco | 197 | Walla Walla County |
| Ice Harbor Water System | WA53AB430 | NTNCWS | Cle Elum | 54 | Franklin County |
| Idlewood Community | WA5335370 | CWS | Coupeville | 111 | Island County |
| Illahee Oyehut | WA5335450 | CWS | Montesano | 971 | Grays Harbor County |
| Ilwaco Water Department City Of | WA5335500 | CWS | Ilwaco | 2,757 | Pacific County |
| Inchelium Water District | WA5335550 | CWS | Tonasket | 540 | Ferry County |
| Index Water Dept | WA5335600 | CWS | Index | 420 | Snohomish County |
| Indian Hills Estates | WA5301966 | CWS | Poulsbo | 282 | Kitsap County |
| Indian Ridge Water Association | WA5335639 | CWS | Tulalip | 216 | Snohomish County |
| Indian Ridge Water Company | WA5335640 | CWS | Arlington | 120 | Island County |
| Indian Village Estates Water Assn | WA5312028 | CWS | Spokane | 90 | Spokane County |
| Indianola | 105300085 | CWS | Suquamish | 78 | |
| Indianola Water | WA5335650 | CWS | Poulsbo | 1,705 | Kitsap County |
| Industrial Development Complex | WA5392023 | NTNCWS | Richland | 52 | Benton County |
| Infra Pacific Water System | WA5307087 | NTNCWS | Lynden | 110 | Whatcom County |
| Ingredion Incorporated | WA53AA251 | NTNCWS | Moses Lake | 35 | Grant County |
| Inland Tarp & Cover | WA53AB186 | NTNCWS | Moses Lake | 76 | Grant County |
| Inlets End | WA5306705 | CWS | Tacoma | 45 | Thurston County |
| Inspire Development Centers | WA5366185 | NTNCWS | Yakima | 144 | Yakima County |
| Intalco Aluminum Corporation Ws | WA5335800 | NTNCWS | Ferndale | 80 | Whatcom County |
| Inwood Beach Club | WA5335880 | CWS | Port Orchard | 80 | Kitsap County |
| Ione Water Dept | WA5335900 | CWS | Ion | 2,395 | Pend Oreille County |
| Iron Springs Park | WA5336020 | CWS | Hoquiam | 62 | Grays Harbor County |
| Island Lake | WA5336150 | CWS | Freeland | 883 | Kitsap County |
| Island Lake Manor | WA5336180 | CWS | Shelton | 233 | Mason County |
| Island Park Mobile Home Park | WA5329599 | CWS | Freeland | 60 | Island County |
| Island Ptba Water System | WA53AC415 | NTNCWS | Coupeville | 75 | Island County |
| Island View Lud 9 | WA5336260 | CWS | Carlsborg | 70 | Clallam County |
| Islandwood Estates | WA5300588 | CWS | Port Orchard | 28 | Kitsap County |
| Isle Aire Beach Association | WA5336268 | CWS | Maple Falls | 125 | Whatcom County |
| Israel Place San Angelo Park | WA5336274 | CWS | Tacoma | 146 | Thurston County |
| Issaquah Valley Water Assn #1 | WA5336300 | CWS | Issaquah | 80 | King County |
| J & B Orchards - South | WA5341814 | CWS | Pasco | 63 | Franklin County |
| Jackson Lake South | WA5357214 | CWS | Tacoma | 225 | Pierce County |
| Jackson Mobile 2 | WA5303021 | CWS | Chehalis | 30 | Lewis County |
| Jackson Park Naval Hospital | WA5305345 | CWS | Silverdale | 2,277 | Kitsap County |
| Jafbro 2 | WA53AD789 | NTNCWS | Shelton | 30 | Mason County |
| Jafbro Associates | WA5387210 | NTNCWS | Shelton | 30 | Mason County |
| Jamestown On Wilcox Lane | WA5306344 | CWS | Sequim | 94 | Clallam County |
| Jaw Farms Inc | WA5308246 | CWS | Malott | 636 | Okanogan County |
| Jd Groom | WA5330020 | NTNCWS | Coupeville | 118 | Island County |
| Jefferson County Water Dist #1 | WA5336705 | CWS | Port Ludlow | 600 | Jefferson County |
| Jesfield Tracts Community Club | WA5336740 | CWS | Port Orchard | 65 | Mason County |
| Johanson | WA5336782 | CWS | Tacoma | 148 | Kitsap County |
| Johnson Creek Water Users Assn | WA5339411 | CWS | Tonasket | 48 | Okanogan County |
| Johnson Point Hoa | WA5336850 | CWS | Port Orchard | 169 | Thurston County |
| Johnston, James W | WA5319001 | CWS | Stevenson | 28 | Skamania County |
| Jones Industrial Park | WA5321253 | NTNCWS | Shelton | 50 | Thurston County |
| Jr Simplot Co | WA5311174 | NTNCWS | Moses Lake | 365 | Grant County |
| Jubilee | WA5305219 | CWS | Yakima | 30 | Walla Walla County |
| Judel Marketing International Inc | WA5318171 | NTNCWS | Mesa | 48 | Franklin County |
| Judys Junction | WA53AB550 | NTNCWS | Selah | 35 | Yakima County |
| Juniper Beach Water District | WA5337250 | CWS | Arlington | 213 | Island County |
| K2 Mine | WA53AA860 | NTNCWS | Republic | 25 | Ferry County |
| K2H Farms-Shop & Office | WA5337336 | NTNCWS | Pasco | 80 | Walla Walla County |
| Kackman Creek | WA5307619 | CWS | Mt Vernon | 330 | Snohomish County |
| Kahler Community Utilities | WA5341991 | CWS | Wentachee | 78 | Chelan County |
| Kahlotus City Of | WA5337400 | CWS | Kahlotus | 262 | Franklin County |
| Kaiser Alum - Trentwood Works | WA5337450 | NTNCWS | Spokane | 954 | Spokane County |
| Kaiser Industrial Park | WA5304966 | NTNCWS | Port Orchard | 43 | Thurston County |
| Kalispel | 105300036 | CWS | Usk | 330 | Pend Oreille County |
| Kamilche Point Community Club | WA5337590 | CWS | Shelton | 39 | Mason County |
| Kamilche Shores | WA5337595 | CWS | Port Orchard | 43 | Mason County |
| Kapowsin Water District | WA5337750 | CWS | Puyallup | 70 | Pierce County |
| Karen Place | WA5302860 | CWS | Tacoma | 53 | Thurston County |
| Kathann Estates Water | WA5337910 | CWS | Marysville | 134 | Snohomish County |
| Keanland Park 761 | WA53AD179 | CWS | Lacey | 268 | Thurston County |
| Keller | 105300006 | CWS | Nespelem | 340 | |
| Kelley Crest | WA5329441 | CWS | Woodland | 45 | Cowlitz County |
| Kelly Road Water Association | WA5337950 | CWS | Lynden | 45 | Whatcom County |
| Kendall Elementary School | WA5308225 | NTNCWS | Deming | 400 | Whatcom County |
| Kens Korner | WA5312520 | NTNCWS | Coupeville | 300 | Island County |
| Kepps Acres Association | WA5317189 | CWS | Pasco | 35 | Franklin County |
| Kershaw Fruit & Cold Storage | WA53AC135 | NTNCWS | Yakima | 150 | Yakima County |
| Kershaw Fruit Company | WA5338280 | NTNCWS | Yakima | 150 | Yakima County |
| Kettle Falls Water Dept | WA5338400 | CWS | Kettle Falls | 2,698 | Stevens County |
| Key Center Water System | WA5338450 | CWS | Gig Harbor | 561 | Pierce County |
| Key Mill Facility | WA53AA858 | NTNCWS | Curlew | 65 | Ferry County |
| Key Peninsula Middle School | WA5325935 | NTNCWS | Gig Harbor | 623 | Pierce County |
| Key Ridge Water System | WA5348466 | CWS | Gig Harbor | 63 | Pierce County |
| Keyport Water | WA5338550 | CWS | Poulsbo | 1,202 | Kitsap County |
| Kicuwa Meadows | WA5338600 | CWS | Port Orchard | 60 | Thurston County |
| Kineth Claim Community Water Assoc. | WA5314371 | CWS | Coupeville | 65 | Island County |
| King County Water District #117 | WA5341980 | CWS | Port Orchard | 95 | King County |
| King County Water District #123 | WA5341996 | CWS | Port Orchard | 242 | King County |
| Kings Meadow Mhp | WA5369168 | CWS | Port Orchard | 90 | Thurston County |
| Kiona Village Court | WA5342175 | CWS | Prosser | 124 | Benton County |
| Kiona West Heights Water Assoc. | WA5316589 | CWS | Cle Elum | 77 | Benton County |
| Kitsap West Mhc Water Co | WA5342635 | CWS | Port Orchard | 190 | Kitsap County |
| Kittitas City Of | WA5342650 | CWS | Kittitas | 2,247 | Kittitas County |
| Kittitas Co Wd #2 | WA5374100 | CWS | Ronald | 242 | Kittitas County |
| Kittitas County Water District #4 | WA5342447 | CWS | Thorp | 510 | Kittitas County |
| Kittitas County Water District #5 | WA5342704 | CWS | Cle Elum | 700 | Kittitas County |
| Kittitas County Water District #7 | WA5385295 | CWS | Cle Elum | 463 | Kittitas County |
| Klickitat Water System | WA5342800 | CWS | Goldendale | 551 | Klickitat County |
| Klingeman Well | WA5307443 | NTNCWS | Othello | 42 | Adams County |
| Knife River Public Water Supply | WA53AE124 | NTNCWS | Port Orchard | 151 | Spokane County |
| Kooley S Harbor Estates | WA5311514 | CWS | Gig Harbor | 58 | Pierce County |
| Koontz Ranch Water System | WA53AD532 | CWS | Oak Harbor | 30 | Island County |
| Kooskooskie Cabin Owners Inc. | WA5334751 | CWS | Walla Walla | 45 | Walla Walla County |
| Kopachuck | WA5343065 | CWS | Tacoma | 236 | Pierce County |
| Kopachuck Middle & Voyager Elem Ws | WA5305549 | NTNCWS | Gig Harbor | 1,150 | Pierce County |
| Kopachuck Ridge Water District | WA5328090 | CWS | Gig Harbor | 185 | Pierce County |
| Kuzmanich Water System | WA5302871 | CWS | Puyallup | 45 | Pierce County |
| Kwonesum | 105300117 | CWS | La Conner | 42 | Skagit County |
| Kyak Ridge Water System | WA5344381 | CWS | Arlington | 66 | Snohomish County |
| Kzh Farms - Higgy | WA5311445 | CWS | Prescott | 29 | Walla Walla County |
| La Conner Water Dept | WA5343350 | CWS | Laconner | 1,821 | Skagit County |
| Labbeemint Water System | WA53AD578 | NTNCWS | White Swan | 25 | Yakima County |
| Lacamas Farmsteads | WA5302117 | CWS | Tacoma | 615 | Pierce County |
| Lackamas Elementary School | WA53AB023 | NTNCWS | Port Orchard | 330 | Thurston County |
| Lacrosse Town Of | WA5343400 | CWS | Lacrosse | 297 | Whitman County |
| Lagoon Point Water District | WA5343550 | CWS | Greenbank | 495 | Island County |
| Lake Alice Water Association | WA5335126 | CWS | Fall City | 90 | King County |
| Lake Alyson | WA5350691 | CWS | Freeland | 463 | Snohomish County |
| Lake Arrowhead | WA5343600 | CWS | Shelton | 343 | Mason County |
| Lake Cassidy Estates | WA5342527 | CWS | Arlington | 70 | Snohomish County |
| Lake Chelan Airport | WA5308257 | NTNCWS | Chelan | 40 | Chelan County |
| Lake Christine Community Club | WA5343793 | CWS | Port Orchard | 53 | Mason County |
| Lake Cushman System 3 | WA5303528 | CWS | Hoodsport | 917 | Mason County |
| Lake Emelia | WA5343878 | CWS | Port Orchard | 37 | Kitsap County |
| Lake Erie Trailer Park | WA5343886 | NTNCWS | Anacortes | 56 | Skagit County |
| Lake Grove Water Association | WA5343940 | CWS | Coupeville | 134 | Island County |
| Lake Holiday Association | WA5383600 | CWS | Port Orchard | 740 | Pierce County |
| Lake Josephine Riviera | WA5343980 | CWS | Anderson Island | 1,380 | Pierce County |
| Lake Ki Sunrise Addition Water | WA5344100 | CWS | Arlington | 96 | Snohomish County |
| Lake Lawrence | WA5322572 | CWS | Tacoma | 914 | Thurston County |
| Lake Lawrence Mobile Home Park | WA5344130 | CWS | Shelton | 80 | Thurston County |
| Lake Limerick Water | WA5344150 | CWS | Shelton | 2,148 | Mason County |
| Lake Lucinda Community Club | WA5344175 | CWS | Shelton | 360 | Thurston County |
| Lake Margaret Water System | WA5344200 | CWS | Carnation | 406 | King County |
| Lake Mayfield Community Club | WA5300914 | CWS | Napavine | 88 | Lewis County |
| Lake Meridian Estates (Mhp) | WA5323341 | CWS | Kent | 154 | King County |
| Lake Minterwood | WA5355210 | CWS | Tacoma | 1,539 | Pierce County |
| Lake Of The Woods Community Club | WA5344387 | CWS | Gig Harbor | 870 | Pierce County |
| Lake Pleasant Mobile Home & Rv Park | WA5363240 | CWS | Beaver | 66 | Clallam County |
| Lake Quinault | WA5370350 | CWS | Port Orchard | 1,003 | Grays Harbor County |
| Lake Quinault School Dist. 97 | 105300119 | NTNCWS | Amanda Park | 210 | |
| Lake Retreat Camp & Conf Center | WA5344400 | CWS | Ravensdale | 404 | King County |
| Lake Retreat Firs #2 Water Assoc. | WA5344416 | CWS | Ravensdale | 38 | King County |
| Lake Ridge Hills Water Assn | WA5314691 | CWS | Electric City | 30 | Grant County |
| Lake Samish Terrace Llc | WA5344540 | CWS | Lynden | 115 | Whatcom County |
| Lake Serene Water System | WA5303451 | CWS | Lake Forest Park | 50 | Pierce County |
| Lake Terrill Water Assoc | WA5344950 | CWS | Lynden | 125 | Whatcom County |
| Lake Tuck | WA5344965 | CWS | Tacoma | 143 | King County |
| Lake Wenatchee Water District | WA53AC567 | CWS | Leavenworth | 86 | Chelan County |
| Lake Wilderness Shore Acres Estate | WA5325060 | CWS | Renton | 75 | King County |
| Lake-O-The-Woods | WA5323456 | CWS | Freeland | 108 | Island County |
| Lakehurst H2O | WA5345086 | CWS | Medical Lake | 170 | Spokane County |
| Lakeland Manor | WA5345087 | CWS | Tumwater | 122 | Thurston County |
| Lakeland Village Water | WA5345090 | CWS | Allyn | 2,120 | Mason County |
| Lakeridge Water Co | WA5344500 | CWS | Port Orchard | 120 | Thurston County |
| Lakeside Llc | WA5345285 | CWS | Kirkland | 178 | Thurston County |
| Lakeside Park | WA5333489 | CWS | Port Orchard | 180 | Ferry County |
| Lakeside Shores Improvement Assoc. | WA5345290 | CWS | Arlington | 166 | Snohomish County |
| Lakeside Village | WA5345303 | CWS | Napavine | 94 | Lewis County |
| Lakeview | WA53AD018 | CWS | Pasco | 50 | Franklin County |
| Lakeview Mobile Terrace | WA5345312 | CWS | Ellensburg | 43 | Grant County |
| Lakeview Park Water Assn | WA5345350 | CWS | Quincy | 1,259 | Grant County |
| Lakeview Terrace | WA5345364 | CWS | Coupeville | 140 | Island County, Lewis County |
| Lakeview Terrace | WA5345365 | CWS | Mossyrock | 41 | Lewis County |
| Lakeview Terrace Mhp | WA5345366 | CWS | Port Orchard | 135 | Lincoln County |
| Lakewood Community | WA5345480 | CWS | Port Orchard | 45 | Mason County |
| Lakewood Garden Tracts Water Assoc | WA5342103 | CWS | Arlington | 33 | Snohomish County |
| Lakewood Heights | WA5317999 | CWS | Shelton | 170 | Mason County |
| Lakewood Manor Association | WA5345400 | CWS | Allyn | 42 | Mason County |
| Lakewood West Water Assn. | WA5344627 | CWS | Coupeville | 75 | Snohomish County |
| Lamb Weston - Paterson | WA5306152 | NTNCWS | Paterson | 250 | Benton County |
| Lamb-Weston Pasco | WA5373920 | NTNCWS | Pasco | 620 | Franklin County |
| Lamont Water System | WA5345650 | CWS | Lamont | 136 | Whitman County |
| Lancaster Heights #1 Water System | WA5345750 | CWS | Clinton | 32 | Island County |
| Lane Mountain Silica Company | WA5345935 | NTNCWS | Valley | 35 | Stevens County |
| Langley City Of | WA5345950 | CWS | Langley | 1,416 | Island County |
| Larch Corrections Center | WA5306461 | CWS | Yacolt | 705 | Clark County |
| Latah Town Of | WA5346150 | CWS | Waverly | 194 | Spokane County |
| Laura Lee Mobile Home Park | WA5346219 | CWS | Yakima | 72 | Yakima County |
| Laurel Park Community Llc | WA5346275 | CWS | Shelton | 165 | Thurston County |
| Laurel West Water Association | WA5346300 | CWS | Lynden | 45 | Whatcom County |
| Lawyer Nursery Inc | WA5304111 | NTNCWS | Olympia | 58 | Thurston County |
| Lazy Acres 351 | WA5346441 | CWS | Lacey | 267 | Thurston County |
| Lazy C | WA5302676 | CWS | Port Townsend | 367 | Jefferson County |
| Leavenworth City Of | WA5346500 | CWS | Leavenworth | 11,041 | Chelan County |
| Lebam | WA53AA361 | CWS | Raymond | 174 | Pacific County |
| Ledgewood Beach Water District | WA5346650 | CWS | Freeland | 202 | Island County |
| Lee | WA5346658 | CWS | Tacoma | 193 | Clallam County |
| Legacy Resort | WA53AB961 | CWS | Othello | 46 | Grant County |
| Legends Casino | 105300153 | NTNCWS | Toppenish | 3,450 | |
| Leif Erikson Rec Assoc | WA5323735 | CWS | Mt Vernon | 320 | Skagit County |
| Leisure Acres Water Association | WA5346695 | CWS | Coupeville | 35 | Island County |
| Lenets Mobile Estates | WA5346737 | CWS | Vancouver | 95 | Thurston County |
| Lenora Water And Sewer District | WA5301281 | CWS | Usk | 75 | Pend Oreille County |
| Lewis Co Water Dist #1 | WA5347000 | CWS | Napavine | 1,174 | Lewis County |
| Lewis Co Water Dist #2 | WA5347001 | CWS | Onalaska | 1,983 | Lewis County |
| Lewis Co Water Dist #3 | WA5365550 | CWS | Randle | 611 | Lewis County |
| Lewis Co Water Sewer Dist #6 | WA5344240 | CWS | Mossyrock | 740 | Lewis County |
| Lewis County Shop/Ethel | WA5306230 | NTNCWS | Chehalis | 30 | Lewis County |
| Lewis River Golf Course | WA5337105 | CWS | Kelso | 300 | Cowlitz County |
| Lewis River Rv Park | WA5329521 | CWS | Woodland | 347 | Cowlitz County |
| Lews 81St 225 | WA5360490 | CWS | Lacey | 92 | Thurston County |
| Libby Road East | WA5347124 | CWS | Tacoma | 85 | Thurston County |
| Liberty Bell High School | WA5300943 | NTNCWS | Winthrop | 642 | Okanogan County |
| Liberty School District #362 | WA5347163 | NTNCWS | Waverly | 486 | Spokane County |
| Lighthouse Christian Center | WA5315475 | NTNCWS | Oak Harbor | 50 | Island County |
| Lighthouse Shores | WA5347200 | CWS | Coupeville | 152 | Island County |
| Ligo Water System | WA5307093 | NTNCWS | Richland | 57 | Benton County |
| Limestone Point Water Company Inc | WA5347280 | CWS | Friday Harbor | 81 | San Juan County |
| Lincoln Creek Lumber Co | WA5305547 | NTNCWS | Port Orchard | 75 | Thurston County |
| Lincoln Hill Estates | WA5343901 | CWS | Port Orchard | 35 | Kitsap County |
| Lincoln Tree Farm | WA5386793 | NTNCWS | Spanaway | 52 | Pierce County |
| Lind Town Of | WA5347350 | CWS | Lind | 903 | Adams County |
| Lineage Logistics | WA5300770 | NTNCWS | Salem | 290 | Benton County |
| Lisecc | WA5343290 | CWS | Lummi Island | 357 | Whatcom County |
| Little Butte Water System | WA5349120 | CWS | Chelan | 101 | Chelan County |
| Little Cedar Park | WA5306396 | CWS | Spanaway | 38 | Pierce County |
| Little Goose Dam | WA5347525 | NTNCWS | Dayton | 62 | Columbia County |
| Little Lake Mobile Home Park | WA5347535 | CWS | Tacoma | 65 | Pierce County |
| Little Mission Creek | WA5301808 | CWS | Belfair | 47 | Mason County |
| Little Tree | WA5302236 | CWS | Tacoma | 143 | King County, Kitsap County |
| Little Valley Apts. | WA5322057 | CWS | Oak Harbor | 30 | Island County |
| Littlerock Elementary | WA5347545 | NTNCWS | Tumwater | 463 | Thurston County |
| Livingston Bay Community Assn | WA5347628 | CWS | Stanwood | 120 | Island County |
| Lochaven Water | WA5347640 | CWS | Arlington | 225 | Snohomish County |
| Locloman Subdivision | WA5347660 | CWS | Kent | 174 | King County |
| Lofall Water System Inc | WA5347670 | CWS | Poulsbo | 81 | Kitsap County |
| Logandale Water Assoc Inc. | WA5347700 | CWS | Auburn | 42 | King County |
| Loma Vista 369 | WA5346164 | CWS | Lacey | 172 | Thurston County |
| Lombard Loop Water Association | WA5347820 | CWS | Wapato | 180 | Yakima County |
| Lone Lake Shores Community Assn | WA5347893 | CWS | Langley | 71 | Island County |
| Lone Rock Water Assn | WA5347925 | CWS | Bremerton | 39 | Kitsap County |
| Long Lake View Est 1 | WA5348030 | CWS | Tacoma | 39 | Kitsap County |
| Long Lake View Est 2 5 | WA5348031 | CWS | Poulsbo | 923 | Kitsap County |
| Long Point Water Company Inc | WA5348050 | CWS | Port Orchard | 182 | Island County |
| Longbranch Shores Water Association | WA5348058 | CWS | Port Orchard | 111 | Pierce County |
| Longhorn Country Estates 687 | WA5330190 | CWS | Lacey | 70 | Thurston County |
| Longview Fibre Paper & Packaging | WA5302842 | NTNCWS | Leavenworth | 97 | Chelan County |
| Longwood Water Association | WA5348160 | CWS | Clinton | 25 | Island County |
| Lookout Point | WA5300045 | CWS | Tacoma | 72 | Kitsap County |
| Loomis Water Users Assn Inc | WA5348200 | CWS | Tonasket | 225 | Okanogan County |
| Loon Lake Acres | WA5338651 | CWS | Loon Lake | 111 | Stevens County |
| Lopez School District #144 | WA5348276 | NTNCWS | Lopez Island | 402 | San Juan County |
| Lora Lee Estates | WA5336991 | CWS | Port Angeles | 60 | Clallam County |
| Los Cedros Mobile Home Park | WA5303619 | CWS | Port Orchard | 63 | Thurston County |
| Lost Lake | WA5302897 | CWS | Port Orchard | 328 | Thurston County |
| Lost River Airport Association | WA5348348 | CWS | Tonasket | 76 | Okanogan County |
| Louella Heights | WA5300585 | CWS | Sequim | 28 | Clallam County |
| Louie Joe Water Association | WA5329014 | CWS | Everson | 471 | Whatcom County |
| Loveland Mobile Estates | WA5348475 | CWS | Port Orchard | 317 | Pierce County |
| Lovely Lane Howa | WA5363695 | CWS | Port Orchard | 40 | Thurston County |
| Lower Elwha Valley | 105300087 | CWS | Port Angeles | 511 | Clallam County |
| Lower Granite Lock & Dam | WA5348705 | NTNCWS | Pomeroy | 120 | Garfield County |
| Lower Monumental Dam - North | WA5348720 | NTNCWS | Kahlotus | 56 | Franklin County |
| Luana Water Assn. | WA5348800 | CWS | Port Orchard | 71 | King County |
| Lucky Eagle Casino | 105300094 | NTNCWS | Oakville | 1,550 | |
| Lwwsd - Agate Heights | WA5352957 | CWS | Bellingham | 147 | San Juan County, Whatcom County |
| Lwwsd - Eagleridge | WA5308118 | CWS | Bellingham | 196 | Whatcom County |
| Lyle Water System | WA5349000 | CWS | Goldendale | 938 | Klickitat County |
| Lyman Water Department | WA5349050 | CWS | Mt Vernon | 705 | Skagit County |
| Lynch Cove | WA5349100 | CWS | Freeland | 721 | Mason County |
| Lynch Cove Div 1 Water Assn | WA5307079 | CWS | Port Orchard | 102 | Mason County |
| Lyon Rd Community Association | WA5314026 | CWS | Oak Harbor | 50 | Island County |
| Lyons Water System | WA53AA796 | CWS | Moses Lake | 28 | Grant County |
| M & R Water Co Lady Dawn Estates | WA5300956 | CWS | Lacey | 83 | Thurston County |
| M J Trailer Ranch | WA5349515 | CWS | Okanogan | 100 | Okanogan County |
| Mabana Shores Association | WA5349600 | CWS | Coupeville | 68 | Island County |
| Mabton City Of | WA5349650 | CWS | Mabton | 2,150 | Yakima County |
| Machias Ridge Homeowners Assoc. | WA5320624 | CWS | Arlington | 324 | Snohomish County |
| Mackaye Harbor Water District | WA5312911 | CWS | Lopez Island | 133 | San Juan County |
| Madison Estates | 105300144 | CWS | Tulalip | 86 | Snohomish County |
| Madrona Beach Comm Water System | WA5349954 | CWS | Stanwood | 539 | Island County |
| Madrona Beach Water Co Inc | WA5349900 | CWS | Port Orchard | 67 | Thurston County |
| Madrona Park | WA5305793 | CWS | Shelton | 73 | Mason County |
| Madrona Point | WA5350075 | CWS | Tacoma | 111 | Pierce County |
| Madrona Ridge Homeowners | WA5350085 | CWS | Port Orchard | 65 | Clallam County |
| Maggie Lake Water District | WA5350235 | CWS | Tahuya | 287 | Mason County |
| Magna Vista Water Corp | WA5350240 | CWS | Woodland | 56 | Clark County, Skamania County |
| Mahoneyville Water Assoc | WA5350295 | CWS | Freeland | 60 | Island County |
| Mainland View Manor | WA5347248 | CWS | Tacoma | 143 | Kitsap County |
| Mains Farm Property Owners | WA5350400 | CWS | Sequim | 358 | Clallam County |
| Majestic Mobile Manor | WA5350425 | CWS | Port Orchard | 238 | Pierce County |
| Majestic Oaks Water System | WA5355860 | CWS | Seattle | 28 | Pierce County |
| Makah Neah Bay | 105300012 | CWS | Neah Bay | 1,300 | Clallam County |
| Malaga Market | WA5393986 | CWS | Quincy | 38 | Chelan County |
| Malaga Water District | WA5350500 | CWS | Malaga | 2,478 | Chelan County |
| Malden Water Dept | WA5350550 | CWS | Rosalia | 215 | Whitman County |
| Malone | WA5350600 | CWS | Napavine | 181 | Grays Harbor County |
| Malott | 105300033 | CWS | Nespelem | 95 | Okanogan County |
| Manhasset Specialty Company | WA5351915 | NTNCWS | Yakima | 142 | Yakima County |
| Mansfield Water System | WA5350850 | CWS | Waterville | 380 | Douglas County |
| Mantheys Country Mobile Park | WA5350900 | CWS | Lynden | 120 | Whatcom County |
| Many Lakes Mobile Home Park | WA5304670 | CWS | Tonasket | 37 | Okanogan County |
| Manzanita Beach | WA5350994 | CWS | Port Orchard | 93 | Thurston County |
| Maple Falls Water Coop | WA5351100 | CWS | Maple Falls | 222 | Whatcom County |
| Maple Glen Community Association | WA5351115 | CWS | Freeland | 200 | Island County |
| Maple Grove | WA5363277 | CWS | Sequim | 132 | Clallam County |
| Maple Haven | WA5351150 | CWS | Silverdale | 74 | Clallam County |
| Maple Hill Park | WA5309356 | CWS | Coupeville | 35 | Island County |
| Maple Hill Water Services | WA5384300 | CWS | Stevenson | 62 | Skamania County |
| Maple Lane Behavioral Health | WA5351195 | CWS | Centralia | 450 | Thurston County |
| Maple Manor Mobile Home Park | WA5351215 | CWS | Tumwater | 120 | Pierce County |
| Maple Shores | WA5316866 | CWS | Port Orchard | 86 | Thurston County |
| Maple Valley | WA5300346 | CWS | Port Orchard | 27 | Thurston County |
| Maple Vista | WA5351350 | CWS | Lake Forest Park | 57 | King County |
| Maples Plat Water System | WA5375340 | CWS | Moses Lake | 30 | Grant County |
| Maplewood Addition Water Coop | WA5351400 | CWS | Renton | 435 | King County |
| Marbello | WA5351530 | CWS | Sun Valley | 245 | Snohomish County |
| Marble Water System | WA5301649 | CWS | Northport | 94 | Stevens County |
| Marcus Water Dept | WA5351550 | CWS | 191 | Ferry County, Stevens County | |
| Marcus Whitman School | WA5351560 | NTNCWS | Yakima | 370 | Yakima County |
| Mariani Water System Inc | WA5351675 | CWS | Black Diamond | 138 | King County |
| Marine Estates Mutual Water Assn | WA5351700 | CWS | Vashion Island | 38 | King County |
| Marine View Home Owners Assn | WA5351724 | CWS | Moses Lake | 87 | Grant County |
| Mariners Cove Beach Club Inc | WA5351730 | CWS | Coupeville | 300 | Island County |
| Marion Water Co Inc | WA5351750 | CWS | Port Orchard | 966 | Pierce County |
| Marlin Hutterian | WA53AA503 | CWS | Marlin | 134 | Grant County |
| Marquez Mobile Home Park | WA5341640 | CWS | Sunnyside | 120 | Yakima County |
| Marshall Community Water Assn | WA5351845 | CWS | Marshall | 74 | Spokane County |
| Martell Mobile Manor | WA5351867 | CWS | Port Orchard | 143 | Kitsap County |
| Martens Add Mutual Water Assoc | WA5351872 | CWS | Spanaway | 79 | Pierce County |
| Martha Boardman | 105311103 | CWS | Wellpinit | 295 | Stevens County |
| Martin Creek Community Assn | WA5351877 | CWS | Tonasket | 109 | Ferry County, Stevens County |
| Martin Way Mobile Home Park | WA5351875 | CWS | Port Orchard | 73 | Thurston County |
| Mary M Knight School | WA5342895 | NTNCWS | Union | 270 | Mason County |
| Marys Garden | WA5351899 | CWS | Yakima | 280 | Yakima County |
| Mason County Lost Lake | WA5348300 | CWS | Port Orchard | 96 | Mason County |
| Mason County Public Works | WA53AB640 | NTNCWS | Shelton | 80 | Mason County |
| Mats View | WA5305536 | CWS | Port Townsend | 52 | Jefferson County |
| Maury Mutual Water Co | WA5352100 | CWS | Vashon | 233 | King County |
| Maxvale 618 | WA5307486 | CWS | Lacey | 88 | Thurston County |
| Maxwelton Water System | WA5310811 | NTNCWS | Mt Vernon | 1,700 | Island County |
| May Volt Hills | WA5317690 | CWS | Tacoma | 106 | Kitsap County |
| Mayfield Kamper Klub | WA5352112 | CWS | Napavine | 87 | Lewis County |
| Mayfield Rv Park | WA5311154 | CWS | Sammamish | 165 | Lewis County |
| Mazama Woods | WA5352118 | CWS | Port Orchard | 45 | King County |
| Mc Pherson Hills Water System | WA5352930 | CWS | Arlington | 30 | Snohomish County |
| Mcaulays Home Sites | WA5352154 | CWS | Yakima | 58 | Yakima County |
| Mccleary City Of | WA5352250 | CWS | Mccleary | 2,753 | Grays Harbor County |
| Mccoy Lake | 105300021 | CWS | Wellpinit | 325 | |
| Mcgee Guest Home | WA5352385 | CWS | Spanaway | 88 | Pierce County |
| Mckees Beach Assoc | WA5324190 | CWS | Mt Vernon | 290 | Snohomish County |
| Mckenna Water District | WA5303521 | CWS | Mckenna | 600 | Pierce County |
| Mcneil Island Water | WA5352900 | CWS | Tumwater | 692 | Pierce County |
| Meadow Lake Water Association | WA5320637 | CWS | Arlington | 171 | Snohomish County |
| Meadow Lane Water Assn | WA5353190 | CWS | Othello | 98 | Adams County |
| Meadow Park Water System | WA5305848 | CWS | Yakima | 48 | Grant County |
| Meadow Ridge | WA5353213 | CWS | Coupeville | 175 | Snohomish County |
| Meadow Wood 689 | WA5363131 | CWS | Lacey | 43 | Thurston County |
| Meadowbrook Homeowners Assn | WA5303449 | CWS | Arlington | 35 | Snohomish County |
| Meadowbrook Village | WA5310774 | CWS | Sequim | 55 | Clallam County |
| Meadowbrook Water Association | WA5353250 | CWS | Lynden | 579 | Whatcom County |
| Meadowmeer | WA5353275 | CWS | Port Orchard | 1,157 | Kitsap County |
| Meadowood Development | WA5353365 | CWS | Mccleary | 220 | Grays Harbor County |
| Meadows | WA5304569 | CWS | Chehalis | 24 | Lewis County |
| Meadows 690 | WA5387784 | CWS | Lacey | 3,100 | Thurston County |
| Mecca Community Association | WA5322888 | CWS | Coupeville | 619 | Island County |
| Melody Pines Mhp Llc | WA5353475 | CWS | Port Orchard | 207 | Thurston County |
| Meridian Heights Water District | WA5353780 | CWS | Port Orchard | 126 | Thurston County |
| Meridian School Complex | WA53AB234 | NTNCWS | Lynden | 900 | Whatcom County |
| Meridian Water System | WA5353820 | CWS | Arlington | 81 | Snohomish County |
| Merwin Village/Park Ppl Co | WA5354061 | CWS | Woodland | 92 | Cowlitz County |
| Mesa Water Department | WA5354100 | CWS | Mesa | 495 | Franklin County |
| Metal Mill 2 | WA5306618 | NTNCWS | Chehalis | 36 | Lewis County |
| Metaline Falls Town Of | WA5354250 | CWS | Newport | 593 | Pend Oreille County |
| Metaline Water Dept | WA5354350 | CWS | Lone | 193 | Pend Oreille County |
| Methow Water System Inc | WA5354370 | CWS | Methow | 45 | Okanogan County |
| Metz Community & Rv Llc | WA5354380 | CWS | Port Orchard | 245 | Benton County |
| Middle Fork Water & Sewer | WA5300315 | CWS | Chehalis | 144 | Lewis County |
| Milagra Water System | WA53AA517 | CWS | Lopez Island | 31 | San Juan County |
| Mill A Water Co | WA5354680 | CWS | Willard | 278 | Skamania County |
| Mill Pond Community Llc | WA5354775 | CWS | Port Orchard | 245 | Kittitas County |
| Miller | WA5382979 | NTNCWS | Napavine | 935 | Lewis County |
| Miller Bay | WA5354683 | CWS | Poulsbo | 1,072 | Kitsap County |
| Millwood City Of | WA5354850 | CWS | Spokane | 1,925 | Spokane County |
| Mineral Heights Association | WA5355035 | CWS | Friday Harbor | 46 | San Juan County |
| Minerva Beach Resort | WA5355060 | CWS | Port Orchard | 80 | Mason County |
| Minerva Terrace | WA5355070 | CWS | Shelton | 85 | Mason County |
| Mini-Pearl Water System | WA5311161 | CWS | Burbank | 28 | Walla Walla County |
| Minter Beach Estates | WA5355160 | CWS | Gig Harbor | 116 | Pierce County |
| Minter Brook Beach Inc. | WA5316892 | CWS | Port Orchard | 45 | Pierce County |
| Minter Creek Rapids | WA5355175 | CWS | Tacoma | 137 | Kitsap County |
| Minter View Water System | WA5357396 | CWS | Gig Harbor | 40 | Pierce County |
| Miracle Ranch | WA5355217 | NTNCWS | Gig Harbor | 418 | Kitsap County |
| Mirrormont | WA5355250 | CWS | Tacoma | 2,083 | King County |
| Mission Creek Corrections Center | WA5355325 | NTNCWS | Belfair | 40 | Mason County |
| Mission Creek Tracts | WA5355320 | CWS | Belfair | 150 | Mason County |
| Mission Road | WA5318237 | NTNCWS | Bellingham | 75 | Whatcom County |
| Mistequa Casino | 105300134 | NTNCWS | Wellpinit | 2,070 | Stevens County |
| Mitchell Point Water Assn | WA5355370 | CWS | Friday Harbor | 81 | San Juan County |
| Moa Tel | WA5307816 | CWS | Port Townsend | 73 | Jefferson County |
| Moab Irrigation Dist #20 | WA5355440 | CWS | Newman Lake | 1,790 | Spokane County |
| Mobbs Water | WA5359876 | NTNCWS | Port Orchard | 100 | Thurston County |
| Monse-Riggan Camp | WA53AC141 | CWS | Brewster | 1,165 | Okanogan County |
| Monte View Estates | WA5355935 | CWS | Montesano | 200 | Grays Harbor County |
| Monterra | WA5355990 | CWS | Sequim | 464 | Clallam County |
| Montessori Country School Ap | WA5308674 | NTNCWS | Suquamish | 125 | Kitsap County |
| Montessori Spring Valley Supply | WA5337300 | NTNCWS | Black Diamond | 121 | King County |
| Mooreland Water Corp | WA5356150 | CWS | Gig Harbor | 68 | Pierce County |
| Morgensen Ground Zero | WA5377356 | NTNCWS | Poulsbo | 42 | Kitsap County |
| Morning Meadows | WA5300950 | CWS | Vancouver | 75 | Clark County |
| Morton City Of | WA5356250 | CWS | Morton | 2,147 | Lewis County |
| Moses Coulee Water Association | WA5305914 | CWS | Wenatchee | 42 | Douglas County |
| Mossyrock Public Utility City Of | WA5356350 | CWS | Mossyrock | 1,553 | Lewis County |
| Mount Adams Vista Water System | WA5341140 | CWS | Benton City | 34 | Benton County |
| Mount Baker Mobile Home Park | WA5356874 | CWS | Bellingham | 87 | Whatcom County |
| Mount Baker School District-Deming | WA5301468 | NTNCWS | Deming | 700 | Whatcom County |
| Mount Baker Water Association | WA5356500 | CWS | Bellingham | 500 | Whatcom County |
| Mount Forest Water System | WA5355874 | CWS | Lake Stevens | 50 | Snohomish County |
| Mount Pleasant School | WA5356527 | NTNCWS | Port Orchard | 72 | Skamania County |
| Mount Si Mobile Home Estates | WA5356560 | CWS | North Bend | 200 | King County |
| Mount St Michaels School & Church | WA5356557 | CWS | Spokane | 162 | Spokane County |
| Mountain Highway Apartments | WA5326955 | CWS | Graham | 56 | Pierce County |
| Mountain Lakeview 619 | WA5356736 | CWS | Lacey | 70 | Lewis County |
| Mountain Loop View Tracts | WA5356528 | CWS | Lake Stevens | 200 | Snohomish County |
| Mountain Ministries Church | WA53AB256 | NTNCWS | Port Orchard | 32 | Cowlitz County |
| Mountain Park Water System | WA5309314 | CWS | Gig Harbor | 198 | Pierce County |
| Mountain Ridge | WA53AB326 | CWS | Roslyn | 28 | Kittitas County |
| Mountain Shores Cc | WA5356780 | CWS | Grapeview | 40 | Mason County |
| Mountain Valley Water System | WA5373560 | CWS | Lacey | 126 | Pierce County |
| Mountain View | WA5311656 | CWS | Union | 41 | Mason County |
| Mountain View | WA5316937 | CWS | White Salmon | 72 | Skagit County, Skamania County |
| Mountain View Association | WA5320527 | CWS | Dallesport | 60 | Klickitat County |
| Mountain View Estates | WA5356830 | CWS | Yakima | 120 | Yakima County |
| Mountain View Mobile Home Park | WA5356875 | CWS | Buckley | 45 | Pierce County |
| Mountain View Terrace Water Inc | WA5338316 | CWS | Snohomish | 87 | Snohomish County |
| Mountain View Water Association | WA5356900 | CWS | Lynden | 186 | Whatcom County |
| Mountain View Water District Inc | WA5356950 | CWS | Kent | 91 | King County |
| Mountainview Elementary School | WA5357200 | NTNCWS | Yakima | 220 | Yakima County |
| Moxee Dairy South Well System | WA53AB540 | NTNCWS | Yakima | 30 | Yakima County |
| Moxie Community Llc | WA5321740 | CWS | Port Orchard | 114 | Yakima County |
| Mt Adams Country Club Estates | WA5304694 | CWS | Toppenish | 31 | Yakima County |
| Mt Adams Orchard Division-Camp B | WA5356397 | CWS | White Salmon | 180 | Klickitat County |
| Mt St Helens National Volcanic Monu | WA53FS102 | NTNCWS | Amboy | 95 | Clark County |
| Mt View Tracts | WA5356851 | CWS | Yakima | 31 | Benton County, Yakima County |
| Mt View Water System | WA5357000 | CWS | Moses Lake | 44 | Grant County |
| Muck Creek Hill | WA5350225 | CWS | Tacoma | 46 | Pierce County |
| Muckleshoot | 105300013 | CWS | Auburn | 3,250 | King County |
| Mud Bay | WA5357400 | CWS | Port Orchard | 145 | Thurston County |
| Mulford Estates | WA5302513 | CWS | Port Orchard | 58 | Thurston County |
| Mulkey Meadows 1 | WA5302519 | CWS | Port Orchard | 93 | Cowlitz County |
| Mullen Hill Terrace Mhp | WA5357598 | CWS | Spokane | 207 | Spokane County |
| Munn Robert Well | WA5357620 | NTNCWS | Prosser | 143 | Benton County |
| Murdock Water | WA5300682 | CWS | Dallesport | 233 | Klickitat County |
| Murphy Elma Veneer | WA5308305 | NTNCWS | Port Orchard | 80 | Grays Harbor County |
| Murray Water System | WA5300698 | NTNCWS | Colbert | 54 | Spokane County |
| Mutiny Bay Park Water Association | WA5357740 | CWS | Coupeville | 156 | Island County |
| Mutiny Sands Club | WA5357900 | CWS | Freeland | 52 | Island County |
| Mutiny View Manor Community Club | WA5357930 | CWS | Freeland | 173 | Island County |
| Mutual Materials Company | WA5335815 | NTNCWS | Spokane Valley | 55 | Spokane County |
| Naches Rv Resort | WA53AD938 | CWS | Port Orchard | 13 | Yakima County |
| Nagler Estates Water Users Assn | WA5320788 | CWS | Yakima | 54 | Yakima County |
| Napavine City Of | WA5358200 | CWS | Napavine | 3,095 | Lewis County |
| Naselle | WA5358350 | CWS | Raymond | 2,073 | Pacific County |
| National Food Nw - Lind | WA5308361 | NTNCWS | Lind | 61 | Adams County |
| Naval Base Kitsap At Keyport | WA5390520 | CWS | Silverdale | 1,540 | Kitsap County |
| Naval Magazine Indian Island | WA5312896 | NTNCWS | Silverdale | 180 | Jefferson County |
| Navy Yard Park | WA5343294 | CWS | Poulsbo | 268 | Kitsap County |
| Nc Machinery Co | WA5335725 | NTNCWS | Yakima | 34 | Yakima County |
| Neals Valley View Addition Wtr Co | WA5358650 | CWS | Yakima | 62 | Yakima County |
| Needle Creek Water System | WA5355376 | CWS | Vashon | 50 | King County |
| Neilton Meadowland Wd 8 A | WA5358750 | CWS | Neilton | 275 | Grays Harbor County |
| Nelson Ridge | WA5306081 | CWS | Tacoma | 232 | Pierce County |
| Neptune Beach Water Assoc | WA5358950 | CWS | Lynden | 200 | Whatcom County |
| Nespelem Agency | 105300007 | CWS | Nespelem | 445 | Okanogan County |
| Nespelem Water Dept | WA5359000 | CWS | Nespelem | 510 | Okanogan County |
| New Arcadia Water System | WA5361533 | CWS | Ravensdale | 40 | King County |
| New Hope Farms | WA5331471 | CWS | Goldendale | 37 | Klickitat County |
| New Horizons | WA5351151 | CWS | Yakima | 49 | Yakima County |
| New Life Christian Center | WA5304020 | NTNCWS | Port Orchard | 120 | Thurston County |
| New Pine Acres | WA53AC152 | CWS | Union | 60 | Mason County |
| New Start Landowners Association | WA5322380 | CWS | Arlington | 90 | Snohomish County |
| New Utsalady Water System Inc | WA5359200 | CWS | Stanwood | 291 | Island County |
| Newaukum Hill Water Assn | WA5301428 | CWS | Chehalis | 493 | Lewis County |
| Newaukum Ventures | WA5326014 | CWS | Napavine | 186 | Lewis County |
| Newaukum Water System | WA5359220 | CWS | Port Orchard | 62 | King County |
| Newberry Hill | WA5306136 | CWS | Poulsbo | 1,143 | Kitsap County |
| Newhalem Water System | WA5359250 | CWS | Mt Vernon | 277 | Whatcom County |
| Newport City Of | WA5359350 | CWS | Newport | 3,331 | Pend Oreille County |
| Nisbet Oyster Company | WA5307624 | NTNCWS | Raymond | 96 | Pacific County |
| Nisqually Commercial Park | WA5359575 | NTNCWS | Shelton | 940 | Thurston County |
| Nisqually Highlands 364 | WA5300953 | CWS | Lacey | 162 | Thurston County |
| Nisqually Park | WA5359588 | CWS | Tacoma | 218 | Pierce County |
| Nisqually Pines Community Club | WA5359591 | CWS | Port Orchard | 2,037 | Thurston County |
| Nisqually Sportsmens Club | WA5359595 | CWS | Port Orchard | 341 | Thurston County |
| Nisqually-Leschi & West Nisqually | 105300014 | CWS | Olympia | 3,200 | Thurston County |
| Noble Woods Water System | WA5302308 | CWS | Lake Forest Park | 37 | King County |
| Noel Canning | WA5307143 | NTNCWS | Yakima | 62 | Yakima County |
| Nooksack Market | 105300084 | NTNCWS | Deming | 400 | |
| Nooksack Valley Water Association | WA5359850 | CWS | Lynden | 1,343 | Whatcom County |
| Nooksack Water Dept | WA5359800 | CWS | Nooksack | 2,427 | Whatcom County |
| Norcliffe Water Association | WA5384566 | CWS | Coupeville | 57 | Island County |
| North 16 Domestic Water Assn | WA5361250 | CWS | Eltopia | 29 | Franklin County |
| North Beverly Beach Association | WA5311239 | CWS | Mt Vernon | 46 | Island County |
| North Bonneville City Of | WA5360150 | CWS | North Bonneville | 1,048 | Skamania County |
| North Boon Water System | WA5318821 | CWS | Freeland | 75 | Island County |
| North Fir Island Water Association | WA53AA747 | CWS | Mt Vernon | 76 | Skagit County |
| North Forty Property Owners Assn | WA5301698 | CWS | Friday Harbor | 27 | San Juan County |
| North Graham Water | WA5351823 | CWS | Lacey | 229 | Pierce County |
| North High Rock Estates W.S. | WA5324841 | CWS | Arlington | 68 | Snohomish County |
| North Lopez Service | WA5360665 | CWS | Lopez Island | 114 | San Juan County |
| North Mason High School | WA5360745 | NTNCWS | Port Orchard | 1,300 | Mason County |
| North Offut Lake Wtr Service | WA5360850 | CWS | Olympia | 97 | Thurston County |
| North Ridge Water Corp | WA5361100 | CWS | Arlington | 135 | Snohomish County |
| North River School Dist 200 | WA5308741 | NTNCWS | Cosmopolis | 86 | Pacific County |
| North Shore Acres | WA5303370 | CWS | Grand Coulee | 101 | Douglas County, Grant County |
| North Slope Estates Property | WA5310761 | CWS | Pasco | 97 | Franklin County |
| North Spokane Irrigation District 8 | WA5361300 | CWS | Spokane | 2,214 | Spokane County |
| North Star Water Assoc | WA5361350 | CWS | Ferndale | 140 | Whatcom County |
| North Terra Vista Water Users Assn | WA5361425 | CWS | Yakima | 52 | Yakima County |
| North Twin Lakeview Assn | WA5361480 | CWS | Port Orchard | 88 | Ferry County |
| North Whidbey Water District | WA5361603 | CWS | Oak Harbor | 568 | Island County |
| Northgate Terrace Community Club | WA5361750 | CWS | Coupeville | 750 | Island County |
| Northport Water System | WA5361850 | CWS | Northport | 290 | Stevens County |
| Northwest | WA5361947 | CWS | Port Orchard | 98 | Snohomish County |
| Northwest Mobile Home Park | WA5307507 | CWS | Lynden | 55 | Whatcom County |
| Northwest Water | WA5302287 | CWS | Coupeville | 99 | Snohomish County |
| Northwood Casino | 105300147 | NTNCWS | Deming | 500 | |
| Northwoods | WA5362100 | CWS | Gig Harbor | 35 | Kitsap County |
| Norwest Mobile Home Park | WA5307574 | CWS | North Bend | 49 | King County |
| Nutrien Us Llc - Kennewick Area | WA5312690 | NTNCWS | Kennewick | 80 | Benton County |
| O-Zi-Ya Community Club | WA5362640 | CWS | Mt Vernon | 120 | Island County |
| Oak Meadows Mobile Home Park | WA5325101 | CWS | Vancouver | 216 | Clark County |
| Oak Park | WA5362675 | CWS | Shelton | 695 | Mason County |
| Oakdell Farms Llc | WA5362695 | CWS | Waverly | 47 | Franklin County |
| Oakesdale Town Of | WA5362700 | CWS | Oaksdale | 492 | Whitman County |
| Oaks The Mobile Home Park | WA5387780 | CWS | Friday Harbor | 143 | San Juan County |
| Oakville City Of | WA5362750 | CWS | Oakville | 1,325 | Grays Harbor County |
| Oasis Water Corporation | WA5319069 | CWS | Pasco | 556 | Benton County |
| Ocean City | WA5301088 | CWS | Montesano | 237 | Grays Harbor County |
| Ocean Spray Cranberries | WA5363012 | NTNCWS | Aberdeen | 100 | Grays Harbor County |
| Ocosta Mobile Home Park Llc | WA5396887 | CWS | Aberdeen | 26 | Grays Harbor County |
| Oddfellows Park | WA5335350 | CWS | Snohomish | 50 | Island County |
| Odessa | WA5363050 | CWS | 986 | Lincoln County | |
| Okanogan Water Department City Of | WA5363200 | CWS | Okanogan | 3,817 | Okanogan County |
| Olalla | WA5363215 | CWS | Tacoma | 239 | Kitsap County, Pierce County |
| Olalla Housing | WA5302273 | CWS | Port Orchard | 32 | Kitsap County |
| Olalla School | WA5363213 | NTNCWS | Port Orchard | 350 | Kitsap County |
| Old Dominion | WA53AD854 | NTNCWS | Port Orchard | 70 | Thurston County |
| Old Orchard Estates Water System | WA5307748 | CWS | Tonasket | 86 | Okanogan County |
| Old Settlers Water Association | WA5363350 | CWS | Custer | 540 | Whatcom County |
| Olga Water Users Inc | WA5363400 | CWS | Eastsound | 392 | San Juan County |
| Olman Point Tracts Club | WA5363410 | CWS | Port Orchard | 57 | Pierce County |
| Olympia Forestry Sciences Lab | WA5325980 | NTNCWS | Olympia | 40 | Thurston County |
| Olympia Oyster Co | WA5363475 | NTNCWS | Port Orchard | 46 | Mason County |
| Olympic Corrections Center | WA5313560 | CWS | Forks | 390 | Clallam County, Jefferson County |
| Olympic Mall | WA5363479 | CWS | Tacoma | 2,681 | Pierce County |
| Olympic Marine View Water Assoc | WA5363480 | CWS | Arlington | 89 | Island County |
| Olympic Park Trailer Court | 105300086 | CWS | Olympia | 169 | Grays Harbor County |
| Olympic Sunset West | WA5363494 | CWS | Gig Harbor | 410 | Pierce County |
| Olympic Trails Water Supply | WA5363448 | CWS | Port Orchard | 44 | Mason County |
| Olympic View | WA5305151 | CWS | Sequim | 33 | Clallam County |
| Olympic View | WA5363500 | CWS | Port Orchard | 73 | Clallam County, Thurston County |
| Olympic View Community Llc | WA5363497 | CWS | Port Orchard | 175 | Kitsap County, Pierce County |
| Olympic View Estates | WA5342421 | CWS | Stanwood | 33 | Island County |
| Olympic View Mobile Park | WA5319110 | CWS | Sequim | 34 | Clallam County |
| Olympic View Water Assoc | WA5363650 | CWS | Silverdale | 41 | Kitsap County |
| Olympic Vista Club Community Water | WA5363655 | CWS | Shelton | 41 | Mason County |
| Olympic Water & Sewer Inc | WA5368700 | CWS | Port Ludlow | 3,086 | Jefferson County |
| Olympic Water System | WA5391460 | CWS | University Place | 75 | Pierce County |
| Olympus Beach Tracts | WA5363700 | CWS | Sequim | 143 | Jefferson County |
| Omak Hud | 105300008 | CWS | Nespelem | 380 | Okanogan County |
| Omicron Investment Company | WA5305244 | NTNCWS | Lacey | 25 | Thurston County |
| Onamac Water System | WA5363907 | CWS | Camano Island | 177 | Island County |
| One Point Fosdick Water Company | WA5335357 | CWS | Port Orchard | 165 | Pierce County |
| Onion Creek School District | WA5305582 | NTNCWS | Colville | 55 | Stevens County |
| Opr H2A | WA53AE120 | CWS | Yakima | 100 | Yakima County |
| Orcas Island Golf Estates | WA5328460 | CWS | Eastsound | 57 | San Juan County |
| Orcas Landing Inc | WA5363990 | NTNCWS | Eastsound | 1,007 | San Juan County |
| Orchard Beach Community | WA5364031 | CWS | Union | 64 | Mason County |
| Orchard Grove | WA5364070 | CWS | Port Orchard | 86 | King County |
| Orchard Homes Water System | WA5364080 | CWS | Moses Lake | 31 | Grant County |
| Orchard Water Assoc | WA5364150 | CWS | Ferndale | 165 | Whatcom County |
| Orient Water Company | WA5364300 | CWS | Republic | 167 | Ferry County |
| Orondo School | WA5304907 | NTNCWS | Wenatchee | 260 | Douglas County |
| Oroville City Of | WA5364400 | CWS | Oroville | 3,256 | Okanogan County |
| Orting 15 | WA5304778 | CWS | Port Orchard | 117 | Pierce County |
| Ostrom Mushroom Farms | WA5364810 | NTNCWS | Port Orchard | 100 | Thurston County |
| Othello Country Club Water Assn | WA5364830 | CWS | Othello | 208 | Adams County, Grant County |
| Othello Manor Llc | WA5364845 | CWS | Port Orchard | 400 | Adams County |
| Ottercrest Estates Water System | WA5355205 | CWS | Port Orchard | 42 | Snohomish County |
| Outlaw Camp | WA53AC008 | CWS | Cle Elum | 193 | Grant County, Kittitas County |
| Outlook Community Water | WA5364937 | CWS | Yakima | 282 | Yakima County |
| Outlook Elementary School | WA5364940 | NTNCWS | Yakima | 600 | Yakima County |
| Owl Creek | WA5303943 | CWS | Woodland | 102 | Cowlitz County |
| Owners Assoc Of Beach Club Condos | WA5329746 | CWS | Lummi Island | 31 | Whatcom County |
| Oysterville Water | WA5329240 | CWS | Oysterville | 72 | Pacific County |
| P And G Orchards Camp 2 | WA5307870 | CWS | Brewster | 489 | Okanogan County |
| Pace International | 105327112 | NTNCWS | Wapato | 48 | Yakima County |
| Pace International | WA5327112 | NTNCWS | Wapato | 48 | Yakima County |
| Pacific Beach/Moclips | WA5300333 | CWS | Montesano | 2,372 | Grays Harbor County |
| Pacific Rim Institute | WA5308450 | NTNCWS | Coupeville | 26 | Island County |
| Pacific Rim Tonewoods Water System | WA53AD528 | NTNCWS | Mt Vernon | 32 | Skagit County |
| Pacific Ventures | WA5329921 | CWS | Tacoma | 69 | Kitsap County |
| Packaging Corporation Of America | WA5307597 | NTNCWS | Wallula | 700 | Walla Walla County |
| Painted Hills Water Association | WA5365640 | CWS | Ephrata | 70 | Grant County |
| Palermo 691 | WA5305277 | CWS | Lacey | 150 | Thurston County |
| Palisades Assn | WA5365700 | CWS | Stanwood | 53 | Island County |
| Palisades School | WA5365720 | NTNCWS | Wenatchee | 40 | Douglas County |
| Palmer Lake | WA5365745 | CWS | Tacoma | 1,924 | Pierce County |
| Palo Verde | WA5302315 | CWS | Sequim | 30 | Clallam County |
| Palomino Fields | WA53AD362 | CWS | Cle Elum | 156 | Kittitas County |
| Palouse Water Dept City Of | WA5365800 | CWS | Palouse | 1,298 | Whitman County |
| Panorama Mobile Home Park | WA5302328 | CWS | Colville | 150 | Stevens County |
| Panorama Place Water Assn | WA5365919 | CWS | Yakima | 220 | Yakima County |
| Panorama Vista | WA5306947 | CWS | Sequim | 75 | Clallam County |
| Panoramic Heights | WA5302890 | CWS | Carlsborg | 40 | Clallam County |
| Panther Lake Community Water System | WA5356806 | CWS | Arlington | 47 | Snohomish County |
| Paradise Cove Resort & Rv Park | WA5313533 | CWS | Castle Rock | 59 | Cowlitz County, Lewis County |
| Paradise Estates | WA5366125 | CWS | Port Orchard | 403 | Mason County |
| Paradise Estates Water Dept Inc | WA5366090 | CWS | Ashford | 309 | Lewis County |
| Paradise Park Water System | WA5366116 | CWS | Ferndale | 200 | Whatcom County |
| Paradise Water Assoc | WA5313960 | CWS | Copalis Beach | 74 | Grays Harbor County |
| Park Orchard Tract 40 | WA5366139 | CWS | Moses Lake | 25 | Grant County |
| Parker | 105338102 | CWS | Toppenish | 300 | Yakima County |
| Parker Spring Acres Water Assoc | WA5322881 | CWS | Moses Lake | 255 | Grant County |
| Parklane Water Association | WA5366204 | CWS | Stanwood | 127 | Island County, Pierce County |
| Parkshore Estates | WA5366146 | CWS | Tacoma | 183 | Mason County |
| Parkside Airpark Owners | WA5326879 | CWS | Battle Ground | 66 | Clark County |
| Parkview Rocky Bay | WA5373626 | NTNCWS | Port Orchard | 40 | Pierce County |
| Parkwood | WA5323191 | CWS | Sun Valley | 65 | Island County |
| Parkwood Apartments | WA5318160 | CWS | Shelton | 60 | Thurston County |
| Parkwood Manor Mhp | WA5366218 | CWS | Coupeville | 301 | Island County |
| Parkwood Mfd Housing Community | WA5302699 | CWS | Sequim | 378 | Clallam County |
| Parkwood Mobile Home Estates | WA5366219 | CWS | Chehalis | 105 | Lewis County |
| Pasados Safe Haven Water System | WA53AC800 | NTNCWS | Sultan | 30 | Snohomish County |
| Paschal Sherman Indian School | 105300009 | CWS | Omak | 220 | |
| Pasco Heights Domestic Water Assn | WA5366350 | CWS | Kennewick | 135 | Franklin County |
| Pasco Port Of 210 | WA5368825 | NTNCWS | Pasco | 500 | Franklin County |
| Pateros Water Department | WA5366450 | CWS | Pateros | 1,149 | Okanogan County |
| Paterson Elementary School | WA5366475 | NTNCWS | West Richland | 142 | Benton County |
| Paterson Heights Water Assn | WA5366479 | CWS | West Richland | 85 | Benton County |
| Patterson Addition | WA5366565 | CWS | Spokane | 22 | Spokane County |
| Patterson Lake Water | WA5366573 | CWS | Napavine | 79 | Thurston County |
| Pattons Retreat Water Assn | WA5366588 | CWS | Oak Harbor | 90 | Island County |
| Pe Ell Town Of | WA5366750 | CWS | Pe Ell | 859 | Lewis County |
| Pebble Beach | WA5366700 | CWS | Shelton | 64 | Mason County |
| Pebble Ridge | WA5347240 | CWS | Port Orchard | 106 | Kitsap County |
| Pederson Harold Well | WA5366727 | NTNCWS | Tacoma | 244 | Pierce County |
| Pederson Place 604 | WA5366734 | CWS | Lacey | 90 | Thurston County |
| Pelican Point By Cascadia Llc | WA5366800 | CWS | Yakima | 1,357 | Grant County |
| Pend Oreille Mine | WA5308269 | NTNCWS | Metaline Falls | 25 | Pend Oreille County |
| Peninsula Mobile Park | WA5366914 | CWS | Allyn | 92 | Pierce County |
| Peninsula Moose Lodge | WA53AD783 | NTNCWS | Ocean Park | 67 | Pacific County |
| Peninsula Pines Park | WA5306794 | CWS | Port Orchard | 60 | Mason County |
| Penn Cove Water And Sewer District | WA5366950 | CWS | Oak Harbor | 460 | Island County |
| Peoples Creek Water System | WA5301916 | CWS | Monroe | 76 | Snohomish County |
| Percie Road Water Association | WA5367020 | CWS | Lynden | 250 | Whatcom County |
| Perry | WA5367045 | NTNCWS | Napavine | 277 | Lewis County |
| Peshastin Domestic Water Assn | WA5367100 | CWS | Cashmere | 177 | Chelan County |
| Peterson | WA5301799 | CWS | Sequim | 26 | Clallam County |
| Peterson Farms | WA5301484 | CWS | Woodland | 290 | Cowlitz County |
| Petrogas Ferndale Terminal | WA5306122 | NTNCWS | Ferndale | 43 | Whatcom County |
| Pheasant Farm Acres | WA5367187 | CWS | Coupeville | 95 | Island County |
| Phelps Road | WA5363210 | CWS | Tacoma | 58 | Kitsap County |
| Phillips 66 Company | WA5355450 | NTNCWS | Ferndale | 288 | Whatcom County |
| Pierce County Fire District 5 | WA5304867 | NTNCWS | Gig Harbor | 76 | Pierce County |
| Pilchuck 26 Tracts | WA5367375 | CWS | Arlington | 66 | Snohomish County |
| Pilchuck Riviera #1 | WA5367380 | CWS | Arlington | 90 | Snohomish County |
| Pilchuck Riviera #2 | WA5367382 | CWS | Snohomish | 107 | Snohomish County |
| Pine Acres Mobile Home Park | WA5367615 | CWS | Spokane | 100 | Spokane County |
| Pine Canyon Growers | WA5305676 | NTNCWS | East Wentachee | 81 | Douglas County |
| Pine Forest Water System | WA5367393 | CWS | Tonasket | 90 | Okanogan County |
| Pine Lake Mobile Home Est 1 3 | WA5367397 | CWS | Tacoma | 207 | Kitsap County |
| Pine Road Estates | WA5337286 | CWS | Gig Harbor | 55 | Kitsap County |
| Pine Terrace Water Association | WA5367600 | CWS | Coupeville | 181 | Island County |
| Pinecrest Subdivison Owners | WA5313909 | CWS | Tonasket | 63 | Okanogan County |
| Pinecroft Mobile Home Park | WA5367623 | CWS | Port Orchard | 248 | Spokane County |
| Pineloch Sun Beach Club | WA5367640 | CWS | Ronald | 190 | Kittitas County |
| Pinewood Community Club Inc | WA5367704 | CWS | Freeland | 47 | Island County |
| Pinewood Glen Mutual Water Assn | WA5367705 | CWS | Spanaway | 70 | Pierce County |
| Pioneer | WA5304387 | CWS | Olympia | 84 | Thurston County |
| Pioneer Hill West | WA5367715 | CWS | Poulsbo | 73 | Kitsap County |
| Pioneer Park Water System | WA5367717 | CWS | Port Orchard | 91 | Island County |
| Pioneer School District | WA5367723 | NTNCWS | Shelton | 903 | Mason County |
| Pioneer Water Company | WA5324885 | CWS | Spokane | 443 | Spokane County |
| Pirates Cove Country Club | WA5367740 | CWS | Shelton | 168 | Mason County |
| Pirnie Road | WA5374656 | CWS | Puyallup | 60 | Pierce County |
| Pit Water Co 328 | WA5305956 | CWS | Lacey | 48 | Grays Harbor County |
| Place Eighteen Hoa | WA5316964 | CWS | Port Orchard | 34 | Kitsap County |
| Plain Flats Water System | WA5339592 | CWS | Leavenworth | 29 | Chelan County |
| Playland Park | WA5330530 | CWS | Yakima | 65 | Yakima County |
| Pleasant Cove | WA5367800 | CWS | Port Orchard | 55 | Mason County |
| Pleasant Forest Camping Club | WA5305303 | CWS | Napavine | 327 | Thurston County |
| Pleasant Harbor Marina | WA5347629 | NTNCWS | Brinnon | 50 | Jefferson County |
| Pleasant Hill Terrace Subdivision | WA5367865 | CWS | Woodland | 30 | Cowlitz County |
| Pleasant Tides Water Co Op | WA5303313 | CWS | Port Angeles | 131 | Jefferson County |
| Pleasant Valley 307 | WA5338081 | CWS | Lacey | 50 | Pierce County |
| Pleasant Valley Water System | WA5367900 | CWS | Ferndale | 73 | Whatcom County |
| Pleasant View Water Company | WA5367950 | CWS | Stanwood | 57 | Island County |
| Plymouth Water District | WA5368045 | CWS | West Richland | 288 | Benton County |
| Pnnl Sequim Campus | WA5310351 | NTNCWS | Richland | 91 | Clallam County |
| Point Allen Water Association | WA5368060 | CWS | Mt Vernon | 102 | Island County |
| Point Fosdick | WA5343040 | CWS | Gig Harbor | 209 | Pierce County |
| Point Lowell/Parkside | WA5368180 | CWS | Arlington | 46 | Island County |
| Point Richmond Hoa | WA5372260 | CWS | Port Orchard | 38 | Pierce County |
| Point Roberts Water District No 4 | WA5395750 | CWS | Point Roberts | 1,440 | Whatcom County |
| Pole Road Water Association | WA5368350 | CWS | Lynden | 1,960 | Whatcom County |
| Polnell Heights Water Association | WA5368370 | CWS | Coupeville | 65 | Island County |
| Polnell Landing Water Assoc. | WA5355476 | CWS | Coupeville | 41 | Island County |
| Polnell Shores Comm Org Inc | WA5368373 | CWS | Coupeville | 200 | Island County |
| Pomeroy City Of | WA5368400 | CWS | Pomeroy | 1,395 | Garfield County |
| Pomona Artesian Irrigation Company | WA5365815 | CWS | Yakima | 150 | Yakima County |
| Pomona View Mobile Park | WA5365820 | CWS | Yakima | 470 | Yakima County |
| Ponderay Newsprint Co - Potable | WA5306970 | NTNCWS | Usk | 70 | Pend Oreille County |
| Ponderosa Community Club Inc | WA5368417 | CWS | Leavenworth | 1,170 | Chelan County |
| Ponderosa Mobile Home Park | WA5368420 | CWS | Ellensburg | 105 | Grant County |
| Ponderosa Mobile Park | WA5368421 | CWS | Port Orchard | 37 | Pierce County |
| Ponderosa Park Water System | WA5315571 | CWS | Goldendale | 381 | Klickitat County |
| Pondilla Estates Community Assoc | WA5368430 | CWS | Coupeville | 52 | Island County |
| Pondoray Shores Water & Sewer | WA5363950 | CWS | Spokane | 63 | Pend Oreille County |
| Port Gamble | WA5300323 | CWS | Poulsbo | 303 | Kitsap County |
| Port Gamble Sklallam | 105300015 | CWS | Kingston | 1,509 | Kitsap County |
| Port Madison Water Company | WA5368750 | CWS | Port Orchard | 233 | Kitsap County |
| Port Of Allyn | WA5368790 | CWS | Shelton | 397 | Mason County |
| Port Of Mattawa - Ind Parks 2 & 4 | WA53AD049 | NTNCWS | Mattawa | 110 | Grant County |
| Port Of Port Townsend Quilcene | WA5325931 | NTNCWS | Port Townsend | 55 | Jefferson County |
| Port Of Royal Slope | WA5300020 | NTNCWS | Royal City | 447 | Grant County |
| Port Of Shelton Johns Prairie | WA5300620 | NTNCWS | Shelton | 328 | Mason County |
| Port Of Shelton Sanderson Field | WA5368835 | NTNCWS | Shelton | 283 | Mason County |
| Port Of Vancouver | WA5368850 | NTNCWS | Vancouver | 317 | Clark County |
| Port Susan Camp Club #1 | 105300090 | CWS | Stanwood | 1,500 | Snohomish County |
| Port Susan Camp Club #2 | 105300091 | CWS | Stanwood | 1,000 | Snohomish County |
| Port Susan Camp Club #3 | 105300092 | CWS | Stanwood | 1,000 | Snohomish County |
| Port Susan Terrace Water | WA5368950 | CWS | Camano Island | 48 | Island County |
| Portland Fair Estates | WA5369008 | CWS | Friday Harbor | 130 | San Juan County |
| Possession Shores Inc | WA5369020 | CWS | Coupeville | 150 | Island County |
| Potlatch Beach Mutual | WA5369050 | CWS | Hoodsport | 109 | Mason County |
| Poulsbo Heights | WA5369152 | CWS | Poulsbo | 80 | Kitsap County |
| Poulsbo Service Center Pse | WA5307074 | NTNCWS | Port Orchard | 55 | Kitsap County |
| Prairie Acres Water System | WA5369157 | CWS | Maple Falls | 90 | Skagit County |
| Prairie Estates Water System | WA5330984 | CWS | Maple Falls | 39 | Skagit County |
| Prairie Point Division 3 | WA53AB569 | CWS | Port Orchard | 42 | Thurston County |
| Prairie Ridge 605 | WA5302356 | CWS | Lacey | 250 | Thurston County |
| Prairie View Estates 759 | WA5304793 | CWS | Lacey | 107 | Pierce County |
| Prairie Villa 230 | WA5369166 | CWS | Lacey | 40 | Thurston County |
| Prairie Village Llc | WA53AB072 | CWS | Napavine | 55 | Thurston County |
| Prairie Village Mobile Home Court | WA5369167 | CWS | Yelm | 40 | Pierce County |
| Prairie Vista | WA5305316 | CWS | Rochester | 63 | Thurston County |
| Precept Wine | WA53AB964 | NTNCWS | Yakima | 63 | Walla Walla County |
| Predator Ridge | WA53AD193 | CWS | Pasco | 66 | Franklin County |
| Prescott Town Of | WA5369250 | CWS | Walla Walla | 522 | Walla Walla County |
| Pressentin Creek Wilderness | WA5369273 | CWS | Concrete | 81 | Skagit County |
| Preston Industrial Park Water Assn | WA5318879 | CWS | Port Orchard | 930 | King County |
| Price Cold Storage 2 | WA53AE119 | NTNCWS | Yakima | 120 | Yakima County |
| Priddy Vista | WA5369350 | CWS | Poulsbo | 210 | Kitsap County |
| Priest Point Beach Water Inc | WA5369450 | CWS | Arlington | 624 | Snohomish County |
| Priest Rapids | WA5329076 | NTNCWS | Beverly | 114 | Grant County |
| Prine Drive Apartments | WA5326774 | CWS | Shelton | 40 | Thurston County |
| Progressive Flat Water Assn | WA5369650 | CWS | Tonasket | 335 | Okanogan County |
| Project Cougar | WA53AE369 | NTNCWS | Port Orchard | 283 | Whitman County |
| Prospect Heights Comm Water Assn | WA5369700 | CWS | Walla Walla | 40 | Walla Walla County |
| Prospect Point Beach Club | WA5369720 | CWS | Port Orchard | 85 | King County, Kitsap County |
| Prospect Water Assn Inc | WA5301842 | CWS | Yakima | 92 | Klickitat County |
| Providence Shmc | WA53AD002 | NTNCWS | Spokane | 3,199 | Spokane County |
| Pse Whitehorn | WA53AE047 | NTNCWS | Lynden | 25 | Whatcom County |
| Pse Wild Horse Maintenance Bldg | WA53AB721 | NTNCWS | Ellensburg | 26 | Kittitas County |
| Puddingstone | WA5319246 | CWS | Port Orchard | 77 | Kitsap County |
| Puget Island | WA5369760 | CWS | Cathlamet | 920 | Wahkiakum County |
| Pump 8 Domestic Water Assn | WA5369900 | CWS | Yakima | 30 | Yakima County |
| Purdy Acres East | WA5370000 | CWS | Tacoma | 85 | Pierce County |
| Purdy Campus System | WA5366927 | NTNCWS | Gig Harbor | 2,000 | Pierce County |
| Puyallup River Rv Park | WA5357264 | CWS | Puyallup | 31 | Pierce County |
| Quail Run | WA5311278 | CWS | Lacey | 66 | Thurston County |
| Quail Run 667 | WA5370185 | CWS | Lacey | 493 | Pierce County |
| Quail Run Mobile Home Park | WA5339424 | CWS | Ellensburg | 165 | Grant County |
| Quartermaster Heights Water Assn | WA5370250 | CWS | Vashon | 70 | King County |
| Queen Anne Water Works Llc | WA5304212 | CWS | Shelton | 28 | Mason County |
| Queets | 105300017 | CWS | Taholah | 200 | Jefferson County |
| Queets Clearwater School | WA5319891 | NTNCWS | Chehalis | 75 | Jefferson County |
| Qui Nai Elt Village | 105300133 | CWS | Taholah | 207 | Grays Harbor County |
| Quilcene | WA53AB292 | CWS | Port Townsend | 119 | Jefferson County |
| Quilcene School District 48 | WA5319176 | NTNCWS | Quilcane | 350 | Jefferson County |
| Quileute Water System | 105300016 | CWS | La Push | 885 | Clallam County |
| Raccoon Point Water System | WA5370670 | CWS | Eastsound | 81 | San Juan County |
| Race Lagoon Heights Association | WA5370650 | CWS | Arlington | 141 | Island County |
| Race Lagoon Water Association | WA5303741 | CWS | Coupeville | 141 | Island County |
| Radar Community Llc | WA5370690 | CWS | Port Orchard | 200 | Adams County |
| Radar Hill Water System | WA5311901 | CWS | Othello | 128 | Franklin County |
| Radar Water Association | WA5370700 | CWS | Othello | 34 | Adams County, Franklin County |
| Rae Lake | WA5370755 | CWS | Shelton | 73 | Mason County |
| Raft Island | WA5370760 | CWS | Tacoma | 575 | Pierce County |
| Rainbow Court | WA5370770 | CWS | Prosser | 120 | Benton County |
| Rainbow Lake | WA5370791 | CWS | Shelton | 168 | Mason County |
| Rainier Christian School | WA5351295 | NTNCWS | Renton | 150 | King County |
| Rainier Pure Beef Co | WA5332737 | NTNCWS | Woodland | 251 | Cowlitz County |
| Rainier School | WA5370850 | CWS | Buckley | 556 | Pierce County |
| Rainier Terrace | WA5303901 | CWS | Port Orchard | 125 | Thurston County |
| Rainier Tracts Water Assn | WA5370910 | CWS | Moses Lake | 61 | Adams County |
| Rainier View | WA5326649 | CWS | Belfair | 37 | Mason County |
| Rainier View Park Addition | WA5370950 | CWS | Port Orchard | 53 | Thurston County |
| Rainier Villa | WA5370970 | CWS | Puyallup | 51 | Pierce County |
| Rainier Water Department | WA5370980 | CWS | Rainier | 3,103 | Thurston County |
| Rainwood | WA5314730 | CWS | Tacoma | 48 | Thurston County |
| Rakwanna Park Water Sys Inc | WA5325586 | CWS | Woodinville | 90 | King County, Snohomish County |
| Ranch | WA5335354 | CWS | Tacoma | 183 | Pierce County |
| Ranch Acre | WA5328551 | CWS | Tacoma | 109 | Thurston County |
| Rangeview | WA53AD017 | CWS | Pasco | 122 | Franklin County |
| Raspberry Ridge Water Association | WA5327631 | CWS | Lynden | 276 | Whatcom County |
| Rathbone Park Water Assoc | WA5371290 | CWS | Ferndale | 240 | Whatcom County |
| Ravens Reach | WA5301031 | CWS | Port Orchard | 47 | Kitsap County |
| Ravensdale Mobile Home Park | WA5371397 | CWS | Ravensdale | 34 | King County |
| Ravensdale Water Supply | WA5371400 | CWS | Renton | 389 | King County |
| Ravenwing Ranch | WA53AB782 | CWS | Seattle | 250 | Chelan County |
| Reardan Town Of | WA5371550 | CWS | Waverly | 1,418 | Lincoln County |
| Red Cedar Estates | WA5371610 | CWS | Tacoma | 34 | Thurston County |
| Red Gate Mobile Home Park | WA5371614 | CWS | Port Orchard | 25 | Pierce County |
| Red Mountain Water Association | WA5306091 | CWS | Pasco | 200 | Benton County |
| Redmon Mobile Home Park | WA5371643 | CWS | Napavine | 105 | Lewis County |
| Redtail Hawk 616 | WA53AA776 | CWS | Lacey | 75 | Thurston County |
| Reed Ranch Road Water | WA5311985 | CWS | Maple Valley | 36 | King County |
| Reflection Water Association | WA5371700 | CWS | Elk | 150 | Spokane County |
| Regency Park | WA5371727 | CWS | Tacoma | 123 | Kitsap County |
| Remolif Addition | WA5371745 | CWS | 76 | King County | |
| Republic City Of | WA5371900 | CWS | Republic | 1,673 | Ferry County |
| Reser Creek Water System | WA5304761 | CWS | Walla Walla | 26 | Walla Walla County |
| Reservation Road | 105300058 | CWS | Wellpinit | 110 | Stevens County |
| Reservoir Hill Maintenance Assn | WA5308401 | CWS | Cle Elum | 34 | Kittitas County |
| Resort And Marina | WA5336421 | CWS | Port Townsend | 409 | Clallam County |
| Rhodena Beach Water District | WA5372150 | CWS | Coupeville | 152 | Island County |
| Rhododendron Heights Water Co | WA5372200 | CWS | Bremerton | 78 | Kitsap County |
| Rhododendron Place | WA5301213 | CWS | Union | 70 | Mason County |
| Rich Acres Water Corp | WA5372227 | CWS | Bridgeport | 30 | Douglas County |
| Richardson Water Company | WA5308371 | CWS | Yakima | 188 | Yakima County |
| Richmond Totten | WA5372267 | CWS | Yelm | 42 | Thurston County |
| Richview | WA53AE302 | CWS | Washtucna | 120 | Franklin County |
| Ridge Water Association | WA5303456 | CWS | Spokane | 615 | Spokane County |
| Ridgeview Estates Community Assn. | WA5326791 | CWS | Freeland | 75 | Island County |
| Ridgeview Estates Water Association | WA5303912 | CWS | Moses Lake | 240 | Grant County |
| Ridgeview Park Estates | WA5304828 | CWS | Spokane | 30 | Spokane County |
| Ridgewood 609 | WA5372414 | CWS | Lacey | 191 | Thurston County |
| Rimrock Water Association | WA5372472 | CWS | Goldendale | 88 | Klickitat County |
| Ringold Domestic Water Corp | WA5372500 | CWS | Othello | 340 | Franklin County |
| Ripplewood Tracts | WA5372620 | CWS | Shelton | 45 | Mason County |
| Ritzville Water Department | WA5372700 | CWS | Ritzville | 1,725 | Adams County |
| Rivendell Water Association | WA5313679 | CWS | Port Orchard | 28 | Mason County |
| River Bend Hoa | WA5372750 | CWS | Snoqualmie | 1,603 | King County |
| River Bend Mobile Park Llc | WA5372809 | CWS | Yakima | 75 | Chelan County |
| River Bend Park Water System | WA5372720 | CWS | Wenatchee | 40 | Chelan County |
| River Bend Water System | WA5372752 | CWS | Newport | 140 | Pend Oreille County |
| River Bluff Water System | WA53AB843 | CWS | Spokane | 330 | Spokane County |
| River Haven | WA5372811 | CWS | Satsop | 113 | Mason County |
| River Lane Community Club | WA5372773 | CWS | Maple Falls | 72 | Skagit County |
| River Oaks Rv Park & Campground | WA5313644 | CWS | Napavine | 50 | Lewis County |
| River Park | WA5372776 | CWS | Tacoma | 277 | Thurston County |
| River Rd Water Association | WA5372800 | CWS | Maple Falls | 30 | Whatcom County |
| River Ridge Estates | WA5338792 | CWS | Pasco | 77 | Franklin County |
| River Ridge Farmworker Housing | WA53AD621 | CWS | Yakima | 98 | Benton County |
| River Road Mobile Home Park | WA5317631 | CWS | Tonasket | 150 | Okanogan County |
| River Rock Tobacco And Fuel | 105338114 | NTNCWS | Arlington | 2,117 | Snohomish County |
| River View Shores Water System | WA5372807 | CWS | Newport | 58 | Pend Oreille County |
| Riverbend Mobile Home Park | WA5372808 | CWS | Port Orchard | 343 | King County |
| Riverhill Homeowners Assn | WA5372810 | CWS | Belfair | 215 | Mason County |
| Riverlea 692 | WA5372817 | CWS | Lacey | 100 | Thurston County |
| Riverside Sd Central Site Schools | WA5372831 | NTNCWS | Chattaroy | 1,320 | Spokane County |
| Riverside Sd Chattaroy Elementary | WA5372828 | NTNCWS | Chattaroy | 306 | Spokane County |
| Riverside Town Of | WA5372850 | CWS | Riverside | 429 | Okanogan County |
| Riverside Villa | WA5372842 | CWS | Port Orchard | 120 | Pierce County |
| Riverside Water Dist #1 | WA5372844 | CWS | Everett | 48 | Snohomish County |
| Rivervale Water Assn | WA5372965 | CWS | Spokane | 48 | Spokane County |
| Riverview | WA5372975 | CWS | Tacoma | 95 | Pierce County |
| Riverwood Park Community Club | WA5373030 | CWS | Port Orchard | 109 | King County |
| Riverwood Water System | WA5373032 | CWS | Tonasket | 43 | Ferry County, Stevens County |
| Rls 1 | WA5312751 | CWS | Mccleary | 38 | Grays Harbor County |
| Roche Harbor Water System Inc | WA5373230 | CWS | Friday Harbor | 2,091 | San Juan County |
| Rochester | WA5373300 | CWS | Rochester | 1,762 | Thurston County |
| Rochester High School | WA5357864 | NTNCWS | Rochester | 1,275 | Thurston County |
| Rochester Mennonite Church | WA53AA775 | NTNCWS | Napavine | 220 | Thurston County |
| Rock Island Dam Power House 2 | WA5373380 | NTNCWS | Wenatchee | 88 | Chelan County |
| Rock Island Dam Powerhouse I | WA5373400 | NTNCWS | Wenatchee | 88 | Douglas County |
| Rock Island Water Dept City Of | WA5373401 | CWS | Rock Island | 3,226 | Douglas County |
| Rockaway Beach Community Assn | WA5306014 | CWS | Coupeville | 40 | Island County |
| Rockaway Beach Water | WA5373450 | CWS | Bainbridge Island | 175 | Kitsap County |
| Rockford Town Of | WA5373550 | CWS | Rockford | 570 | Spokane County |
| Rocky Acres Water System | WA5316234 | CWS | Port Orchard | 61 | King County |
| Rocky Bay | WA5373620 | CWS | Tacoma | 34 | Pierce County |
| Rocky Point Community Club | WA5304629 | CWS | Coupeville | 320 | Island County |
| Rocky Point Water District 12 | WA5302052 | CWS | Bremerton | 1,831 | Kitsap County |
| Rocky River Road Community Site | 105300047 | CWS | Nespelem | 260 | Okanogan County |
| Roederland Water Association | WA5373750 | CWS | Lynden | 150 | Whatcom County |
| Rolf Bruun | WA5308915 | CWS | Mt Vernon | 36 | Skagit County |
| Rolling Firs Evergreen Terrace | WA5373975 | CWS | Tacoma | 514 | Thurston County |
| Rolling Hills-Glencairn | WA5374000 | CWS | Oak Harbor | 872 | Island County |
| Rom 626 | WA5371930 | CWS | Lacey | 74 | Lewis County |
| Rondelay Meadows | WA5374130 | CWS | Tacoma | 90 | Jefferson County |
| Roosevelt Lake Ranch | WA5347283 | CWS | Wilbur | 487 | Lincoln County |
| Roosevelt Regional Landfill | WA5304301 | NTNCWS | Yakima | 75 | Klickitat County |
| Roosevelt Water Association | WA5374150 | CWS | Snohomish | 3,530 | Snohomish County |
| Roosevelt Water System | WA5374160 | CWS | Goldendale | 219 | Klickitat County |
| Rosalia Town Of | WA5374250 | CWS | Rosalia | 831 | Whitman County |
| Rosario | WA5374270 | CWS | Eastsound | 1,426 | San Juan County |
| Rose Avenue Water Association | WA5366932 | CWS | Port Orchard | 53 | Kitsap County |
| Rose Valley Friends Church | WA5301096 | NTNCWS | Woodland | 212 | Cowlitz County |
| Rose Valley School | WA5300370 | NTNCWS | Kelso | 211 | Cowlitz County |
| Rosedale Community Club | WA5374364 | CWS | Tacoma | 96 | Pierce County |
| Rosedale East | WA5309490 | CWS | Tacoma | 798 | Pierce County |
| Rosedale Heights Trailer Park | WA5374371 | CWS | Tacoma | 444 | Pierce County |
| Roseland Community Club Association | WA5374372 | CWS | Arlington | 210 | Snohomish County |
| Rosemount | WA5374375 | CWS | Gig Harbor | 320 | Pierce County |
| Roslyn City Of | WA5374400 | CWS | Roslyn | 2,099 | Kittitas County |
| Rougk Well #2 | WA5307866 | CWS | Yakima | 36 | Yakima County |
| Roy 325Th 668 | WA5324721 | CWS | Lacey | 185 | Pierce County |
| Roy City Of | WA5345027 | CWS | Roy | 1,214 | Pierce County |
| Royal City Water | WA5374700 | CWS | Royal City | 3,389 | Grant County |
| Royal Coachman Mobil Est | WA5374705 | CWS | Ferndale | 37 | Whatcom County |
| Royal Water District | WA5300543 | CWS | Othello | 430 | Grant County |
| Royal Watermaster - Qcbid | WA5374750 | NTNCWS | Quincy | 37 | Grant County |
| Royalwood | WA5374743 | CWS | Tacoma | 111 | Kitsap County |
| Roza Heights Water Assn | WA5374800 | CWS | Prosser | 110 | Benton County |
| Rubicon Property 1 Llc | WA53AD513 | NTNCWS | Ferndale | 25 | Whatcom County |
| Rumbolz Sunset Water System | WA5314446 | CWS | Snoqualmie | 106 | King County |
| Rustemeyer Mobile Home Park | WA5375028 | CWS | Port Orchard | 44 | Grays Harbor County |
| Rustic Ridge | WA5372935 | CWS | Othello | 221 | Spokane County |
| Rustlewood | WA5375027 | CWS | Shelton | 322 | Mason County |
| Rutsatz Road | 105300088 | CWS | Deming | 150 | Whatcom County |
| Ryanwood | WA5319601 | CWS | Tacoma | 64 | Pierce County |
| Ryanwood Improvement Assn | WA5375070 | CWS | Port Orchard | 108 | Pierce County |
| Ryderwood Improvement & Service As | WA5375100 | CWS | Kelso | 434 | Cowlitz County |
| S & I | WA5375154 | CWS | Tacoma | 482 | Pierce County |
| S&P Properties | WA5300530 | NTNCWS | Port Orchard | 27 | Mason County |
| Sackman | 105300031 | CWS | Suquamish | 500 | Kitsap County |
| Saddle Mountain Water Assoc. | WA5375200 | CWS | Moses Lake | 219 | Adams County, Grant County |
| Saddle Ridge Water Users | WA5375205 | CWS | Yakima | 60 | Yakima County |
| Sage Hills Estates 1 | WA5301371 | CWS | Warden | 38 | Grant County |
| Sage Hills Second Water System | WA5304398 | CWS | Warden | 34 | Franklin County, Grant County |
| Salish Sea Water System | WA53AC941 | CWS | Lopez Island | 26 | San Juan County |
| Salkum Water Supply | WA5375550 | CWS | Salkum | 103 | Lewis County |
| Salt Aire Mobile Terrace | WA5375616 | CWS | Olympia | 23 | Thurston County |
| Sam Lake Improvement Association | WA5375636 | CWS | Marysville | 128 | Snohomish County |
| Samish Farms Water Assn | WA5375645 | CWS | Bow | 1,017 | Skagit County |
| Samish Grade School | WA5375648 | NTNCWS | Mt Vernon | 250 | Skagit County |
| Samish River Park, Inc. | WA5375670 | CWS | Burlington | 227 | Skagit County |
| San Juan County Pw - Beaverton | WA53AD538 | NTNCWS | Friday Harbor | 61 | San Juan County |
| San Juan Estates Water Association | WA5318605 | CWS | Oak Harbor | 36 | Island County |
| San Juan Fairways Owners Assn | WA5375765 | CWS | Friday Harbor | 40 | San Juan County |
| San Juan Ranchos | WA5375795 | CWS | Friday Harbor | 35 | San Juan County |
| San Juan Vista | WA5375800 | CWS | Sekiu | 94 | Clallam County |
| San Poil | 105338123 | NTNCWS | Nespelem | 86 | |
| Sand Hill Elementary | WA5360381 | NTNCWS | Port Orchard | 650 | Mason County |
| Sandberg Water Assn | WA5322691 | CWS | Freeland | 37 | Island County |
| Sandflat Water Association | WA5309064 | CWS | Tonasket | 260 | Okanogan County |
| Sandra Avenue 627 | WA5354591 | CWS | Lacey | 30 | Lewis County |
| Sandwood Heights Subdivision | WA5375893 | CWS | Woodland | 126 | Cowlitz County |
| Sandy Hook Park Community Club | WA5375950 | CWS | Port Orchard | 593 | Kitsap County |
| Sandy Hook Yacht Club Estates | WA5376050 | CWS | Freeland | 540 | Island County |
| Sandy Point Improvement Co | WA5376105 | CWS | Lynden | 2,098 | Whatcom County |
| Sandy Shore & Sunnyside Meadows | WA5376145 | CWS | Newport | 83 | Pend Oreille County |
| Santiago Water Association | 105300081 | CWS | Taholah | 95 | Grays Harbor County |
| Saratoga Beach Owners Assn | WA5376240 | CWS | Freeland | 425 | Island County |
| Saratoga Shores Community Club | WA5376250 | CWS | Mt Vernon | 35 | Island County |
| Saratoga Terrace Water | WA5310516 | CWS | Camano Island | 30 | Island County |
| Saratoga Water District | WA5376300 | CWS | Coupeville | 477 | Island County |
| Satsop Business Park | WA5318777 | NTNCWS | Aberdeen | 544 | Grays Harbor County |
| Satsop School District 104 | WA5313901 | NTNCWS | Satsop | 70 | Grays Harbor County |
| Sauk Mountain Estates | WA5317049 | CWS | Rockport | 45 | Skagit County |
| Sauk-Suiattle | 105311106 | CWS | Darrington | 80 | Skagit County |
| Sawyerwood Estates Water System | WA5376460 | CWS | Port Orchard | 46 | King County |
| Sawyerwood Water System | WA5376462 | CWS | Black Diamond | 32 | King County |
| Scandialand Mobile Home Park | WA5376467 | CWS | Port Orchard | 48 | Kitsap County |
| Scatchet Head Water District | WA5376470 | CWS | Coupeville | 900 | Island County |
| Scatter Creek Ranch 760 | WA53AA916 | CWS | Lacey | 268 | Thurston County |
| Scenic Beach Water Company | WA5376500 | CWS | Camano Island | 122 | Island County |
| Scenic Heights W A Inc | WA5376520 | CWS | Oak Harbor | 78 | Island County |
| Scenic Shores Water Company | WA5376530 | CWS | Port Orchard | 761 | Thurston County |
| Schenk Water System | WA5334934 | NTNCWS | Port Orchard | 90 | Pierce County |
| Schluter Water Association | WA5376650 | CWS | Arlington | 224 | Snohomish County |
| Schmid | WA5376658 | CWS | Tacoma | 37 | Kitsap County |
| Schoonover Hutterian Brethren | WA53AB043 | CWS | Odessa | 73 | Adams County |
| Scootenay Water Assn Inc | WA5376750 | CWS | Connell | 120 | Franklin County |
| Scott Lake | WA5376787 | CWS | Port Orchard | 1,604 | Thurston County |
| Sea View | WA5307314 | CWS | Montesano | 170 | Grays Harbor County |
| Sea View | WA5376920 | CWS | Gig Harbor | 111 | Grays Harbor County, Kitsap County |
| Sea View Water Llc | WA5377148 | CWS | Freeland | 496 | Island County |
| Seabold Heights | WA5376973 | CWS | Port Orchard | 36 | Kitsap County |
| Seabold United Methodist Church | WA53AC591 | NTNCWS | Port Orchard | 90 | Kitsap County |
| Seamount Estates Community | WA5376986 | CWS | Port Orchard | 92 | Jefferson County |
| Seashore Villa | WA5376998 | CWS | Port Orchard | 225 | Thurston County |
| Seatons Grove | 105300115 | CWS | Nespelem | 115 | |
| Seattle City Light-Boundary Dam | WA5312521 | NTNCWS | Metaline Falls | 110 | Pend Oreille County |
| Seavue Assoc | WA5376925 | CWS | Port Orchard | 65 | Kitsap County, Mason County |
| Seawest Water System | WA5337544 | CWS | Mt Vernon | 38 | Island County |
| Sect 11 Div 1 Ridgeview Water Assn | WA5372410 | CWS | Moses Lake | 79 | Adams County |
| Sehmel Road | WA5320481 | CWS | Tacoma | 42 | Pierce County |
| Selah Hills Homeowners Cooperative | WA5379280 | CWS | Yakima | 300 | Yakima County |
| Selah United Methodist Church | WA5377398 | NTNCWS | Yakima | 38 | Yakima County |
| Selandia Manor Water Assn | WA5377410 | CWS | Yakima | 130 | Yakima County |
| Selkirk School District #70 | WA5377448 | NTNCWS | Ione | 121 | Pend Oreille County |
| Sentinel Gap Water Assn | WA5376620 | CWS | Mattawa | 226 | Grant County |
| Settle Water | WA5302211 | CWS | Poulsbo | 26 | Kitsap County |
| Seven Bays Estates Unlimited | WA5377651 | CWS | Spokane | 431 | Lincoln County |
| Seventh Day Adventist School | WA5377671 | NTNCWS | Port Orchard | 33 | Kitsap County, Mason County |
| Seventh Heaven Country Club | WA5377675 | CWS | Monroe | 48 | Snohomish County |
| Sexton | WA5377670 | CWS | Olympia | 35 | Thurston County |
| Shadowood | WA5313584 | CWS | Shelton | 154 | Mason County |
| Shady Pines Trailer Court | WA5377777 | CWS | Spokane | 70 | Spokane County |
| Shangri La Community Club | WA5377846 | CWS | Sedro Woolley | 41 | Skagit County |
| Shangri-La Shores Inc | WA5377850 | CWS | Coupeville | 56 | Island County |
| Shawnee Hill Condominium Ws | WA5319901 | CWS | Vashon | 44 | King County |
| Shawnee Hills Water System | WA5377957 | CWS | Gig Harbor | 83 | Pierce County |
| Shaws Cove | WA5377960 | CWS | Tacoma | 217 | Pierce County |
| Shelton Valley Child Development | WA5304434 | NTNCWS | Port Orchard | 221 | Mason County |
| Sherman Hill | WA5332980 | CWS | Belfair | 37 | Kitsap County, Mason County |
| Shiloh Water System | WA5325897 | CWS | Port Orchard | 40 | Stevens County |
| Shipp Construction | WA53AB078 | NTNCWS | Ethel | 32 | Lewis County |
| Shirona Water System | WA5378373 | CWS | Coupeville | 243 | Island County |
| Shoal Bay & Swift Bay Water Assn. | WA5378398 | CWS | Lopez Island | 35 | San Juan County |
| Shore Acres Water Company | WA5378455 | CWS | Gig Harbor | 540 | Pierce County |
| Shore Hill | WA5378650 | CWS | Shelton | 101 | Mason County |
| Shorebrook Community Club | WA5378600 | CWS | Port Orchard | 148 | Mason County |
| Shorecrest | WA5378618 | CWS | Tacoma | 289 | Pierce County |
| Shorecrest Estates Water Co | WA5378620 | CWS | Shelton | 1,321 | Mason County |
| Shorewood | WA5343530 | CWS | Port Orchard | 54 | Thurston County |
| Shyne School Water System | WA5305016 | NTNCWS | Port Orchard | 79 | King County |
| Sierra Country Club | WA5378975 | CWS | Coupeville | 400 | Island County |
| Sierra Vista Water Association | WA5378970 | CWS | Camano Island | 197 | Island County |
| Sierra Water System | WA5304643 | CWS | Puyallup | 355 | Pierce County |
| Silvana Water Association | WA5379050 | CWS | Mt Vernon | 153 | Snohomish County |
| Silver Fox 693 | WA5359953 | CWS | Lacey | 50 | Thurston County |
| Silver Hawk | WA53AC166 | CWS | Port Orchard | 499 | Thurston County |
| Silver Lake Rd Acreage Tracts | WA5310587 | CWS | Coupeville | 73 | Island County |
| Silver Lake Water | WA5379245 | CWS | Freeland | 425 | Island County |
| Silver Sands Condo Water | WA5302345 | CWS | Moses Lake | 37 | Grant County |
| Silver Springs Estates | WA5379275 | CWS | Tacoma | 80 | Kitsap County |
| Silver Springs Estates Comm Assn | WA5379276 | CWS | Coupeville | 61 | Snohomish County |
| Silverbrook Mh & Rv | WA5379190 | CWS | Napavine | 42 | Lewis County |
| Simplot Feeders Ltd | WA5300552 | NTNCWS | Kennewick | 40 | Walla Walla County |
| Single Tree Acres | WA5312366 | CWS | Vancouver | 90 | Clark County |
| Single Tree Estates | WA5379423 | CWS | Port Orchard | 146 | Thurston County |
| Sivo Acres | WA5323911 | CWS | Tacoma | 66 | Kitsap County |
| Skagit Co Pud - Alger | WA5301400 | CWS | Mount Vernon | 446 | Skagit County |
| Skagit Co Pud - Cedargrove | WA5311917 | CWS | Mount Vernon | 400 | Skagit County |
| Skagit Co Pud - Marblemount | WA53AA642 | CWS | Mount Vernon | 238 | Skagit County |
| Skagit Co Pud - Potlatch Beach | WA5369034 | CWS | Mount Vernon | 75 | Skagit County |
| Skagit Co Pud Rockport | WA5373600 | CWS | Mount Vernon | 175 | Skagit County |
| Skagit Co Water District #1 | WA5300392 | CWS | Mt Vernon | 1,974 | Skagit County |
| Skagit View Village Water System | WA5396879 | CWS | Mount Vernon | 232 | Skagit County |
| Skamania Elementary School | WA5379540 | NTNCWS | Port Orchard | 91 | Skamania County |
| Skamania Landing Owners Assn | WA5309251 | CWS | Port Orchard | 132 | Skamania County |
| Skamokawa Water System | WA5305198 | CWS | Cathlamet | 267 | Wahkiakum County |
| Skate Creek Terrace Association | WA5379650 | CWS | Napavine | 39 | Lewis County |
| Ski Hill Domestic Water Association | WA5302413 | CWS | Cashmere | 102 | Chelan County |
| Ski View Estates | WA5302182 | CWS | Issaquah | 50 | Thurston County |
| Skokomish | 105300020 | CWS | Skokomish Nation | 1,150 | Mason County |
| Skookum Chuck Water Association | WA5379800 | CWS | Lynden | 415 | Whatcom County |
| Skookum Ranch | WA5308586 | CWS | Tacoma | 60 | Kitsap County |
| Skookumchuck 612 | WA5379860 | CWS | Lacey | 130 | Thurston County |
| Skookumchuck Mobile Manor | WA5379835 | CWS | Napavine | 90 | Thurston County |
| Sky Meadows Community Assoc. | WA5342705 | CWS | Coupeville | 58 | Island County |
| Sky Meadows Ranch Country Club Wtr | WA5380005 | CWS | Cle Elum | 98 | Kittitas County |
| Skykomish Water Dept | WA5380100 | CWS | Skykomish | 324 | Chelan County, King County |
| Skyland Park Water Association | WA5380130 | CWS | Port Orchard | 47 | King County |
| Skyline Acres Inc | WA5380200 | CWS | Moses Lake | 151 | Grant County |
| Skyline East Orchard | WA53AB958 | CWS | Wenatchee | 93 | Grant County |
| Skyline Mobile Home Park | WA5380205 | CWS | Yakima | 340 | Yakima County |
| Skyline Ridge | WA53AE053 | CWS | Port Orchard | 20 | Kittitas County |
| Skyline Water System Inc | WA5380210 | CWS | Moses Lake | 293 | Grant County |
| Skyline West Community Club | WA5380212 | CWS | Coupeville | 109 | Island County |
| Skyview | WA5331141 | CWS | Port Orchard | 110 | Snohomish County |
| Sleeper Acres Comm. Assoc. Inc. | WA5329901 | CWS | Coupeville | 56 | Island County |
| Sleepy Hollow Apts | WA5380345 | CWS | Spokane | 35 | Spokane County, Whitman County |
| Smith Cove | WA5313651 | CWS | Port Orchard | 30 | Mason County |
| Smith Gardens Water System | WA5304287 | NTNCWS | Arlington | 90 | Snohomish County |
| Smith Prairie 251 | WA5357851 | CWS | Lacey | 42 | Thurston County |
| Smith Road Water Association | WA5380550 | CWS | Bellingham | 77 | Whatcom County |
| Smithville | WA53AA101 | CWS | Forks | 28 | Clallam County |
| Smugglers Cove Water System | WA5301666 | CWS | Friday Harbor | 27 | San Juan County |
| Smwe - Canoe Ridge Winery | WA5302380 | NTNCWS | Yakima | 45 | Benton County |
| Smwe - Columbia Crest Winery | WA5317641 | NTNCWS | Yakima | 218 | Benton County |
| Smwe - Vineyard 8 | WA5304424 | NTNCWS | Yakima | 41 | Benton County |
| Snee-Oosh Land Co | WA5380800 | CWS | Mt Vernon | 123 | Skagit County |
| Sno Pud 1 - May Creek | WA5352105 | CWS | Everett | 1,374 | Snohomish County |
| Sno Pud 1 - Skylite Tracts | WA5380220 | CWS | Everett | 415 | Snohomish County |
| Sno Pud 1 - Storm Lake Ridge | WA5344431 | CWS | Everett | 786 | Snohomish County |
| Sno Pud 1 - Sunday Lake | WA5385205 | CWS | Everett | 561 | Snohomish County |
| Sno Pud 1 - Warm Beach | WA5393000 | CWS | Everett | 2,977 | Snohomish County |
| Sno Pud 1- Creswell | WA5306325 | CWS | Everett | 100 | Snohomish County |
| Snoqualmie Casino | 105300151 | NTNCWS | Snoqualmie | 3,000 | |
| Snoqualmie Valley Land Company Inc | WA5381073 | NTNCWS | North Bend | 80 | King County |
| Snow Creek | WA5301220 | CWS | Port Townsend | 156 | Jefferson County |
| Snow Creek Water System | WA5381100 | CWS | Chelan | 41 | Chelan County |
| Snowblaze | WA5381120 | CWS | Mead | 121 | Spokane County |
| Snug Harbor Mhc | WA5381150 | CWS | Arlington | 71 | Snohomish County |
| Snug Harbor Owners Club | WA5381146 | CWS | Port Orchard | 39 | Thurston County |
| Soap Lake Water Dept | WA5381300 | CWS | Quincy | 2,399 | Grant County |
| Solar Pines Water Assn | WA5339268 | CWS | Loon Lake | 36 | Stevens County |
| Solmar Water | WA5381315 | CWS | Sequim | 895 | Clallam County |
| South Auburn Water Association | WA5381400 | CWS | Black Diamond | 212 | King County |
| South Bainbridge | WA5381451 | CWS | Poulsbo | 4,414 | Kitsap County |
| South Bay | WA53AB160 | NTNCWS | Port Orchard | 114 | Thurston County |
| South Bay Elementary School | WA5381465 | NTNCWS | Port Orchard | 615 | Thurston County |
| South Bay Terraces Water Company | WA5381475 | CWS | Port Orchard | 61 | Thurston County |
| South Bend Water Department | WA5381500 | CWS | South Bend | 2,930 | Pacific County |
| South Cle Elum Water Dept | WA5381600 | CWS | South Cle Elum | 541 | Kittitas County |
| South Fox Island Water System | WA5315532 | CWS | Gig Harbor | 493 | Pierce County |
| South Hills Water Users Assn Inc | WA5381851 | CWS | Yakima | 135 | Yakima County |
| South Othello Water Users | WA5382200 | CWS | Othello | 35 | Adams County |
| South Prairie Town Of | WA5382300 | CWS | South Prairie | 489 | Pierce County |
| South Shady Acres Water | WA5313253 | CWS | Port Orchard | 85 | Pierce County |
| South Whidbey Assembly Of God | WA5364921 | NTNCWS | Freeland | 184 | Island County |
| Southcreek #1 | WA5325707 | CWS | Tacoma | 69 | Pierce County |
| Southgate Water Company | WA5356344 | CWS | Pasco | 175 | Benton County |
| Southside Elementary School | WA5303270 | NTNCWS | Shelton | 260 | Mason County |
| Southworth Elementary | WA5301252 | NTNCWS | Port Orchard | 550 | Thurston County |
| Spanaway 192Nd 669 | WA5315531 | CWS | Lacey | 183 | Pierce County |
| Spanaway Village Water System | WA5322916 | CWS | Lacey | 125 | Pierce County |
| Spangle Town Of | WA5382870 | CWS | Spangle | 270 | Spokane County |
| Spencer Glen | WA5382963 | CWS | Port Orchard | 55 | Mason County |
| Spo Co Water Dist 3 Sys 5 | WA5393355 | CWS | Spokane | 485 | Spokane County |
| Spo Co Water Dist 3 Sys 6 | WA5393356 | CWS | Spokane | 358 | Spokane County |
| Spo Co Water Dist 3 Sys 8 | WA5393358 | CWS | Spokane | 375 | Spokane County |
| Spo Co Water Dist 3 Sys 9 | WA5393359 | CWS | Spokane | 105 | Spokane County |
| Spokane Christian Center | WA5328377 | NTNCWS | Spokane | 250 | Spokane County |
| Spokane Hutterian Brethren | WA5318375 | CWS | Reardan | 140 | Spokane County |
| Sportsman Trailer Park | WA5383116 | CWS | Ellensburg | 151 | Adams County |
| Sprague City Of | WA5383150 | CWS | Sprague | 570 | Lincoln County |
| Spring Glen Association | WA5383295 | CWS | Fall City | 273 | King County |
| Spring Glen Mobile Home Park | WA5383290 | CWS | Mercer Island | 96 | King County |
| Spring Point Homeowners Association | WA5383335 | CWS | Deer Harbor | 85 | San Juan County |
| Springdale Town Of | WA5383400 | CWS | Springdale | 315 | Stevens County |
| Springwood | WA5383408 | CWS | Union | 90 | Mason County |
| Spruce Road | WA5383424 | CWS | Tacoma | 80 | Kitsap County |
| Squaxin Consolidated | 105300146 | CWS | Shelton | 1,500 | Mason County |
| St John Town Of | WA5375300 | CWS | St John | 800 | Whitman County |
| Stahl Hutterian Brethren | WA5307764 | CWS | Ritzville | 122 | Adams County |
| Star Lake Community Club | WA5383680 | CWS | Port Orchard | 201 | Mason County |
| Starbuck City Of | WA5383750 | CWS | Starbuck | 147 | Columbia County |
| Starks Mobile Home Court | WA5383825 | CWS | Yakima | 60 | Yakima County |
| Stars Early Learning Center | 105304455 | NTNCWS | Yakima | 50 | Yakima County |
| Stars Early Learning Center | WA5304455 | NTNCWS | Yakima | 50 | Yakima County |
| Startup Water District | WA5383850 | CWS | Startup | 643 | Snohomish County |
| Stavis 1 | WA5363216 | CWS | Port Orchard | 32 | Kitsap County |
| Stavis Creek | WA5383884 | CWS | Poulsbo | 63 | Kitsap County |
| Stavis View Estates | WA5300837 | CWS | Seabeck | 30 | Kitsap County |
| Steamboat Island Fuel | WA5304727 | NTNCWS | Port Orchard | 126 | Thurston County |
| Steamboat Island Inc | WA5383900 | CWS | Port Orchard | 73 | Thurston County |
| Steamboat Square | WA5300519 | NTNCWS | Port Orchard | 310 | Thurston County |
| Steptoe Water/Sewer District | WA5324881 | CWS | Colfax | 210 | Whitman County |
| Stevens Co Pud - Addy | WA5300367 | CWS | Loon Lake | 253 | Stevens County |
| Stevens Co Pud - Clayton | WA5313450 | CWS | Loon Lake | 725 | Stevens County |
| Stevens Co Pud - Deer Lake | WA5393380 | CWS | Loon Lake | 2,884 | Stevens County |
| Stevens Co Pud - Denison | WA53AB833 | CWS | Loon Lake | 60 | Spokane County |
| Stevens Co Pud - Dolomite | WA5329808 | CWS | Loon Lake | 60 | Stevens County |
| Stevens Co Pud - Echo Estates | WA5302590 | CWS | Loon Lake | 75 | Stevens County |
| Stevens Co Pud - Halfmoon Ranchos | WA5330420 | CWS | Loon Lake | 216 | Spokane County |
| Stevens Co Pud - Jump Off Joe | WA5337165 | CWS | Loon Lake | 204 | Stevens County |
| Stevens Co Pud - Loon Lake | WA5348250 | CWS | Loon Lake | 2,487 | Stevens County |
| Stevens Co Pud - Mission Ridge | WA5330434 | CWS | Loon Lake | 120 | Stevens County |
| Stevens Co Pud - River Park Estates | WA5307813 | CWS | Loon Lake | 66 | Spokane County |
| Stevens Co Pud - Riverside | WA5318290 | CWS | Loon Lake | 365 | Spokane County |
| Stevens Co Pud - Spokane Lake Park | WA5383034 | CWS | Loon Lake | 532 | Spokane County |
| Stevens Co Pud - Waitts Lake | WA5391130 | CWS | Loon Lake | 1,216 | Stevens County |
| Stevens Co Pud - West Shore | WA5395450 | CWS | Loon Lake | 505 | Spokane County |
| Stevenson Water Dept | WA5384250 | CWS | Stevenson | 4,702 | Skamania County |
| Stillaguamish Natural Resources | 105338116 | NTNCWS | Arlington | 31 | |
| Stillaguamish Village | 105338118 | NTNCWS | Mount Vernon | 210 | |
| Stilliridge | WA5318707 | CWS | Port Orchard | 83 | Snohomish County |
| Stone Creek Estates Water Assn. | WA5384530 | CWS | Kent | 62 | King County |
| Stonewater Ranch | WA5301824 | NTNCWS | Leavenworth | 154 | Chelan County |
| Stratford Road Estates | WA5307542 | CWS | Moses Lake | 312 | Grant County |
| Strathview Water District 16 | WA5384620 | CWS | Medical Lake | 351 | Spokane County |
| Strattonwood | WA5384618 | CWS | Tacoma | 220 | Kitsap County |
| Strawberry Hill | WA5384625 | CWS | Poulsbo | 235 | Kitsap County |
| Stretch Island Fruit | WA5305742 | NTNCWS | Allyn | 70 | Mason County |
| Strohs | WA5384670 | CWS | Tacoma | 3,192 | Pierce County |
| Suburban Hills Community Assoc | WA5337911 | CWS | Oak Harbor | 46 | Island County |
| Suburban Mobile Park | WA5384730 | CWS | Coupeville | 60 | Island County |
| Suddenview | WA5312451 | CWS | Port Orchard | 60 | Snohomish County |
| Sugarloaf Water System | WA5346316 | CWS | Kent | 468 | King County |
| Sultan Estates Water System | WA5384760 | CWS | Lake Forest Park | 340 | Snohomish County |
| Sulwhanon | 105300141 | CWS | Deming | 150 | Whatcom County |
| Sumas Rural Water Association | WA5384850 | CWS | Sumas | 612 | Whatcom County |
| Sumas Water Dept | WA5384870 | CWS | Sumas | 2,157 | Whatcom County |
| Summerhill | WA5384898 | CWS | Tacoma | 42 | Thurston County |
| Summerland | WA5384903 | CWS | Coupeville | 85 | Island County |
| Summers Circle Water Llc | WA5307937 | CWS | Walla Walla | 82 | Walla Walla County |
| Summerset Meridian | WA5384907 | CWS | Port Orchard | 96 | Thurston County |
| Summerset West Water Association | WA5385080 | CWS | Othello | 240 | Adams County |
| Summit Valley School District #2 | WA53AA199 | NTNCWS | Addy | 90 | Stevens County |
| Summit View Water System | WA5303303 | CWS | Kennewick | 1,869 | Benton County |
| Sun Acres Road & Water Assn | WA5385121 | CWS | Yakima | 47 | Yakima County |
| Sun Country Estates 1-2-3 | WA5385123 | CWS | Wenatchee | 277 | Kittitas County |
| Sun Cove Public Water System | WA5385124 | CWS | Cashmere | 716 | Chelan County, Douglas County |
| Sun Desert Inc | WA5319936 | CWS | Moses Lake | 27 | Grant County |
| Sun Harbor Water District #3 | WA5385129 | CWS | Burbank | 187 | Walla Walla County |
| Sun Island Maintenance Assn | WA5385128 | CWS | Cle Elum | 97 | Kittitas County |
| Sun Meadows | WA5304511 | CWS | Sequim | 295 | Clallam County |
| Sun Mountain Resort | WA5385135 | NTNCWS | Twisp | 376 | Okanogan County |
| Sun Tides Community Llc | WA5386280 | CWS | Port Orchard | 63 | Yakima County |
| Sun Tides Vista Homeowners Assn | WA5386284 | CWS | Yakima | 350 | Yakima County |
| Sun Valley Orchard Farmworker | WA53AD198 | CWS | Wenatchee | 52 | Grant County |
| Sun-Tides Rv Park | WA5385138 | CWS | Yakima | 100 | Yakima County |
| Sunburst Estates Water Assn | WA5385201 | CWS | Moses Lake | 100 | Adams County |
| Suncadia Resort | WA53AA317 | CWS | Cle Elum | 2,640 | Kittitas County |
| Suncrest Plat Water System | WA5385207 | CWS | Tonasket | 260 | Okanogan County |
| Sundance Improvement Association | WA5385209 | CWS | Kennewick | 100 | Benton County |
| Sundown M Ranch | WA5331314 | NTNCWS | Yakima | 126 | Yakima County |
| Sundquist | WA5302272 | NTNCWS | Port Orchard | 25 | Kitsap County |
| Sundquist Sunnyslope Domestic | WA53AD011 | CWS | Yakima | 196 | Yakima County |
| Sundquist Twh-Terrace Heights | WA53AD423 | CWS | Yakima | 192 | Yakima County |
| Sunland Estates Homeowners Assn | WA5385240 | CWS | Quincy | 1,480 | Grant County |
| Sunland Shores | WA5385257 | CWS | Sun Valley | 143 | Clallam County |
| Sunland Water District | WA5385260 | CWS | Sequim | 2,235 | Clallam County |
| Sunlight Shores Country Club | WA5333039 | CWS | Coupeville | 150 | Island County |
| Sunny Shores Community Club | WA5385330 | CWS | Arlington | 60 | Snohomish County |
| Sunnybank Water System | WA5301266 | CWS | Cashmere | 58 | Chelan County |
| Sunnyhills | WA5323391 | CWS | Sun Valley | 61 | Lincoln County |
| Sunnyslope | WA5385550 | CWS | Shelton | 2,112 | Kitsap County |
| Sunnyslope Mutual Water System | WA5352550 | CWS | Vashion Island | 85 | King County |
| Sunnyview Terrace Association Inc | WA5385605 | CWS | Gig Harbor | 45 | Pierce County |
| Sunrise Beach Association | WA5385641 | CWS | Lopez Island | 27 | San Juan County |
| Sunrise Estates Water System | WA5313451 | CWS | Moses Lake | 33 | Franklin County |
| Sunrise Hills Community W S | WA5385818 | CWS | Oak Harbor | 186 | Island County |
| Sunrise Terrace Community Llc | WA5385925 | CWS | Port Orchard | 152 | Pierce County |
| Sunrise Water Association | WA5316177 | CWS | Moses Lake | 250 | Grant County |
| Sunserra At Crescent Bar | WA53AA745 | CWS | Quincy | 1,000 | Douglas County, Grant County |
| Sunset Acres Water Assn | WA5385940 | CWS | Moses Lake | 61 | Grant County |
| Sunset Acres Water Association | WA5385950 | CWS | Moses Lake | 40 | Adams County |
| Sunset Beach | WA5386040 | CWS | Port Orchard | 228 | Mason County |
| Sunset Development Comm Club | WA5386075 | CWS | Coupeville | 92 | Island County |
| Sunset Domestic Water Assn | WA5386100 | CWS | Pasco | 60 | Franklin County |
| Sunset Farm | WA5386115 | CWS | Port Orchard | 45 | Kitsap County |
| Sunset Mobile Court | WA5386130 | CWS | Albion | 51 | Whitman County |
| Sunset Park Water Co | WA5386140 | CWS | Port Orchard | 21 | King County |
| Sunset Ranch Owners Assoc | WA5386150 | CWS | Eastsound | 76 | San Juan County |
| Sunset Ridge Community Assn | WA5386158 | CWS | Anacortes | 140 | Island County |
| Sunset Water & Maintenance Assoc | WA5306514 | CWS | Lummi Island | 35 | Whatcom County |
| Sunset Water Association | WA5386200 | CWS | Bellingham | 174 | Whatcom County |
| Sunset Water Distribution Assoc | WA5386202 | CWS | Stanwood | 159 | Island County |
| Sunset West | WA5361761 | CWS | Coupeville | 75 | Island County |
| Sunset West Water Association | WA5386205 | CWS | Mt Vernon | 62 | Skagit County |
| Sunsetvue | WA5363921 | CWS | Rochester | 42 | Lewis County |
| Sunshine Acres | WA5386250 | CWS | Tacoma | 1,074 | Clallam County |
| Sunshine Early Learning Center | WA53AA282 | NTNCWS | Springdale | 35 | Spokane County |
| Sunvale Acres 4Th Add Water System | WA5386294 | CWS | Newport | 56 | Pend Oreille County |
| Sunvista Sunlight Beach Hoa | WA5385160 | CWS | Coupeville | 500 | Island County |
| Sunwood Graham | WA5362034 | CWS | Port Orchard | 315 | Pierce County |
| Sunwood Lakes Homeowners Assoc Inc | WA5386304 | CWS | Port Orchard | 925 | Thurston County |
| Suquamish Regional Public Water System | 105338117 | NTNCWS | Suquamish | 1,874 | |
| Surfrest Park Water Company | WA5386450 | CWS | Poulsbo | 123 | Kitsap County |
| Surfside Homeowners | WA5386470 | CWS | Ocean Park | 2,687 | Pacific County |
| Swanrun Water System | WA5307663 | CWS | Freeland | 60 | Island County |
| Swantown Water District | WA5396042 | CWS | Freeland | 318 | Island County |
| Sward 278 | WA5306046 | CWS | Lacey | 25 | Lewis County |
| Swiftwater Trailer Park | WA5386633 | CWS | Cle Elum | 27 | Kittitas County |
| Swinomish | 105300032 | CWS | La Conner | 1,212 | Skagit County |
| Sydney Heights Water Assn | WA5386647 | CWS | Walla Walla | 130 | Walla Walla County |
| Sylvan Terrace Condominiums | WA5303010 | CWS | Shelton | 64 | Thurston County |
| Syringa Heights Mobile Home Park | WA5307741 | CWS | Chattaroy | 52 | Spokane County |
| T & T Farmworker Housing | WA53AD593 | NTNCWS | Quincy | 67 | Grant County |
| T-11 Farmworker Housing | WA53AC293 | CWS | Wenatchee | 99 | Grant County |
| Tacoma Narrows Airport | WA5386789 | NTNCWS | University Place | 202 | Pierce County |
| Taggares Fruit Co | WA5380798 | NTNCWS | Burbank | 152 | Walla Walla County |
| Tahja Ii | WA5303052 | CWS | Port Orchard | 51 | Mason County |
| Taholah | 105300018 | CWS | Taholah | 1,600 | Grays Harbor County |
| Tahoma Meadows 694 | WA5307215 | CWS | Lacey | 80 | Thurston County |
| Tahoma Valley Country Club | WA5303388 | CWS | East Olympia | 50 | Thurston County |
| Tahuya River Valley Water District | WA5387115 | CWS | Shelton | 367 | Mason County |
| Tahuyeh Lake Community Club | WA5387116 | CWS | Port Orchard | 560 | Kitsap County |
| Tala Point | WA5360203 | CWS | Port Orchard | 45 | Jefferson County |
| Talcott Ridge 695 | WA53AA139 | CWS | Lacey | 102 | Thurston County |
| Tall Cedars Estates Water Assoc. | WA5387120 | CWS | Ferndale | 100 | Whatcom County |
| Tall Firs Mobile Home Park | WA5387122 | CWS | Port Orchard | 177 | Thurston County |
| Tamoshan | WA5387140 | CWS | Olympia | 260 | Thurston County |
| Tampico Drive Well Owners Assn | WA5387144 | CWS | Yakima | 42 | Yakima County |
| Tapps Island Water System | WA5387181 | CWS | Lake Tapps | 1,501 | Pierce County |
| Tatoosh Water Company | WA5387189 | CWS | Mt Vernon | 387 | Snohomish County |
| Taylor Bay Beach Club Inc | WA5387175 | CWS | Elma | 175 | Pierce County |
| Taylor Road Water System | WA5387195 | CWS | Coupeville | 50 | Island County |
| Taylor United | WA5345864 | NTNCWS | Port Orchard | 187 | Mason County |
| Teddy Bear Corner Llc | WA5304157 | NTNCWS | Yakima | 60 | Yakima County |
| Teen Challenge | WA5301819 | CWS | Spokane | 61 | Spokane County |
| Tekoa City Of | WA5387300 | CWS | Tekoa | 1,076 | Whitman County |
| Tel Company 3 | WA5393945 | CWS | Freeland | 75 | Island County |
| Tel Company 4 | WA5376976 | CWS | Freeland | 69 | Island County |
| Tel Company#1 | WA5303099 | CWS | Freeland | 210 | Island County |
| Tempo Lake Water Co | WA5387375 | CWS | Port Orchard | 246 | Thurston County |
| Ten Four | WA5387385 | NTNCWS | Union | 26 | Mason County |
| Teronda West Country Club Assn. | WA5387520 | CWS | Coupeville | 127 | Island County |
| Terrace Park Water Association | WA5387600 | CWS | Yakima | 50 | Yakima County |
| Terry Lane 354 | WA5387622 | CWS | Lacey | 308 | Pierce County |
| The Buttes | WA5308253 | CWS | Puyallup | 973 | Pierce County |
| The Meadows Water System Llc | WA5360095 | CWS | Kirkland | 127 | King County |
| The Village At Colockum Ridge | WA5301639 | CWS | Quincy | 144 | Grant County |
| Thornton Water Association | WA5388050 | CWS | Ferndale | 55 | Whatcom County |
| Three Fingers | WA5361129 | CWS | Port Orchard | 118 | Mason County |
| Three Lakes Water Association | WA5388150 | CWS | Snohomish | 2,198 | Snohomish County |
| Three Lakes Water District | WA5388140 | CWS | Malaga | 650 | Chelan County |
| Three Ponds Mobile Park & Apts. | WA5301125 | CWS | Puyallup | 113 | Pierce County |
| Thunder Ridge Water System | WA5388200 | CWS | Coupeville | 145 | Island County |
| Thunderbird Terrace Water System | WA5305067 | CWS | Monroe | 75 | Snohomish County |
| Thurston County Eoc | WA53AC512 | NTNCWS | Olympia | 30 | Lewis County, Thurston County |
| Tierra | WA5312987 | NTNCWS | Leavenworth | 57 | Chelan County |
| Tieton Hills Water Co | WA5388298 | CWS | Yakima | 75 | Yakima County |
| Tieton Water Dept City Of | WA5388300 | CWS | Yakima | 1,475 | Yakima County |
| Tiger Lake Terrace Tracts | WA5304237 | CWS | Union | 70 | Mason County |
| Tiger Mtn Tracts | WA5388315 | CWS | Issaquah | 30 | King County |
| Tiger Tracts | WA5329801 | CWS | Loon Lake | 90 | Stevens County |
| Tilley Maintenance Facility | WA5300909 | NTNCWS | Port Orchard | 200 | Thurston County |
| Tilton River Mobile Home Park | WA5356700 | CWS | Chehalis | 40 | Lewis County |
| Timaru Community Water Association | WA5398215 | CWS | Oak Harbor | 27 | Island County |
| Timberlake Community Club Inc | WA5388370 | CWS | Shelton | 2,337 | Mason County |
| Timberlane Mobile Estates | WA5388383 | CWS | Napavine | 120 | Thurston County |
| Timberlane Mobile Home Park | WA5388381 | CWS | Napavine | 63 | Lewis County |
| Timberlane Village Water | WA5388385 | CWS | Baring | 51 | King County |
| Timberline Mobile Home Park | WA5388386 | CWS | Port Orchard | 240 | Spokane County |
| Timberline Travelers Park | WA5388398 | CWS | Concrete | 51 | Skagit County |
| Timberline Village 628 | WA5388388 | CWS | Lacey | 378 | Lewis County |
| Toad Holler | WA53AB876 | NTNCWS | Port Orchard | 27 | Kitsap County |
| Tokul Creek Community | WA5388625 | CWS | Snoqualmie | 34 | King County |
| Toledo Municipal | WA5388660 | CWS | Toledo | 1,944 | Lewis County |
| Tolmie Cove | WA5388665 | CWS | Port Orchard | 125 | Thurston County |
| Tolmie Park 239 | WA5388667 | CWS | Lacey | 195 | Thurston County |
| Tonasket Water System | WA5388700 | CWS | Tonasket | 2,398 | Okanogan County |
| Toop Water Assn Inc | WA5388785 | CWS | Yakima | 80 | Yakima County |
| Torboy Industrial Park | WA53AC257 | NTNCWS | Republic | 66 | Ferry County |
| Touchet School | WA5388890 | NTNCWS | Walla Walla | 303 | Walla Walla County |
| Toutle Community Regional Water | WA5388905 | CWS | Kelso | 3,215 | Cowlitz County |
| Toutle River View | WA5388920 | CWS | Kelso | 45 | Cowlitz County |
| Towns Mobile Home Park | WA5388945 | CWS | Cashmere | 37 | Chelan County |
| Township 29 Water Association | WA5300484 | CWS | Mt Vernon | 42 | Island County |
| Township Place | WA5301379 | CWS | Napavine | 56 | Thurston County |
| Trails End | WA5389050 | CWS | Port Orchard | 117 | King County |
| Trails End Water District | WA5389055 | CWS | Shelton | 211 | Mason County |
| Trails West Subdivision | WA5389080 | CWS | 27 | Stevens County | |
| Tranquilcene Trailer Park | WA53AB025 | CWS | Quilcene | 20 | Jefferson County |
| Transalta Centralia Generation | WA5365484 | NTNCWS | Centralia | 200 | Lewis County, Thurston County |
| Travis Jack 264 | WA5333924 | CWS | Lacey | 150 | Pierce County |
| Treasure Island Country Club | WA5389150 | CWS | Port Orchard | 321 | Mason County |
| Treveri | WA53AB942 | NTNCWS | Yakima | 141 | Yakima County |
| Tri-City Water District #45 | WA5389400 | CWS | Kennewick | 300 | Benton County |
| Tribal Complex | 105300025 | CWS | Toppenish | 907 | Yakima County |
| Triton Cove | WA5389447 | CWS | Port Townsend | 204 | Jefferson County |
| Triton Head Assn | WA5389450 | CWS | Port Orchard | 176 | Mason County |
| Trophy Lake Golf Course | WA53AA761 | NTNCWS | Port Orchard | 163 | Kitsap County |
| Trowbridge Court Condo Assn | WA5300339 | CWS | Port Orchard | 23 | Clallam County |
| Tukes Mountain Homeowners | WA5328340 | CWS | Woodland | 60 | Clark County |
| Tula Young Hastings Farm - Wsu | WA5389520 | NTNCWS | Pullman | 40 | Whitman County |
| Tulalip Shores Water System | WA5389550 | CWS | Arlington | 74 | Snohomish County |
| Tulalip Wood Water System | WA5389620 | CWS | Arlington | 52 | Snohomish County |
| Tulare Beach Association | WA5389650 | CWS | Everett | 54 | Snohomish County |
| Tulare Estates | 105300155 | CWS | Tulalip | 38 | |
| Tulip Meadows | WA53AD861 | CWS | Woodland | 33 | Cowlitz County |
| Turf Trails Domestic | WA53AB914 | CWS | Cle Elum | 30 | Kittitas County |
| Turtlerock Homeowners Association | WA5312490 | CWS | Wenatchee | 133 | Chelan County |
| Twanoh Falls Beach Club | WA5310751 | CWS | Shelton | 481 | Mason County |
| Twanoh Heights Community Club | WA5300153 | CWS | Union | 118 | Mason County |
| Twanoh Terrace Water Co | WA5360190 | CWS | Union | 75 | Mason County |
| Twenty-Three 800 Tiger Mountain | WA5390875 | CWS | Port Orchard | 129 | King County |
| Twin Firs Mobile Estates | WA5389930 | CWS | Port Orchard | 175 | Pierce County |
| Twin Lakes Hud | 105300010 | CWS | Nespelem | 42 | Stevens County |
| Twin Pines Mobile Home Park | WA5331790 | CWS | Tonasket | 25 | Okanogan County |
| Twin Roads Water Association | WA5302408 | CWS | Arlington | 50 | Snohomish County |
| Twin View Estates Community Assoc | WA5390032 | CWS | Greenbank | 110 | Island County |
| Twisp Town Of | WA5390050 | CWS | Twisp | 1,173 | Okanogan County |
| Two Rivers Resort | 105300123 | CWS | Wellpinit | 480 | Lincoln County |
| Tyee Beach 2 Water Association | WA5335671 | CWS | Mukilteo | 98 | Island County |
| Tyee Beach Water Association | WA5390100 | CWS | Camano Island | 158 | Island County |
| Underwood | WA5390200 | CWS | Carson | 1,000 | Skamania County |
| Union | WA5351920 | CWS | Union | 700 | Mason County |
| Uniontown Water Works | WA5390400 | CWS | Uniontown | 366 | Whitman County |
| University Heights | WA5390543 | CWS | Friday Harbor | 76 | San Juan County |
| Upper Columbia Academy | WA5390685 | CWS | Spangle | 407 | Spokane County |
| Upper Preston Water Assn | WA5390700 | CWS | Falls City | 150 | King County |
| Upper Skagit | 105300048 | CWS | Sedro Woolley | 365 | Skagit County |
| Us Naval Radio Station(T)Jim Crk | WA5311496 | NTNCWS | Everett | 111 | Snohomish County |
| Usace Illia Residential Area | WA5348704 | CWS | Pomeroy | 46 | Garfield County, Whitman County |
| Usda Agricultural Research Service | WA5304776 | NTNCWS | Yakima | 100 | Yakima County |
| Useless Bay Shores | WA5333261 | CWS | Coupeville | 56 | Island County |
| Utsalady Heights Owners Assn | WA5300982 | CWS | Mt Vernon | 240 | Island County |
| Utsalady Point | WA5390850 | CWS | Mt Vernon | 54 | Island County |
| Utsalady Water | WA5390847 | CWS | Arlington | 80 | Island County |
| Vader-Enchanted Valley | WA5390900 | CWS | Chehalis | 985 | Lewis County |
| Valicoff Yvh H2A Housing | WA53AD483 | CWS | Yakima | 96 | Yakima County |
| Valle Lindo Homes | WA5392475 | CWS | Walla Walla | 787 | Walla Walla County |
| Valley High Park | WA5390976 | CWS | Coupeville | 141 | Island County |
| Valley Meadows 240 | WA5390981 | CWS | Lacey | 148 | Lewis County |
| Valley Nut & Bolt | WA53AC014 | NTNCWS | Olympia | 28 | Thurston County |
| Valley Of The Horses Water Dist #12 | WA5390979 | CWS | Cheney | 70 | Spokane County |
| Valley View Estates Water Assn | WA5390993 | CWS | Mt Vernon | 113 | Skagit County |
| Valley View Estates Water System | WA5306321 | CWS | Tonasket | 28 | Okanogan County |
| Valley View Mobile Home Park | WA5343054 | CWS | Shelton | 30 | Thurston County |
| Valley View Mobile Park Llc | WA5390998 | CWS | Port Orchard | 126 | King County |
| Valley View Water Assoc | WA5391000 | CWS | Lynden | 185 | Whatcom County |
| Valley Water System | WA5301250 | CWS | Puyallup | 2,259 | Pierce County |
| Valleybrook Village | WA5391080 | CWS | Bonney Lake | 65 | Pierce County |
| Valleyhi Community Club | WA5390975 | CWS | Cashmere | 242 | Chelan County |
| Vanridge Mobile Home Park | WA5315637 | CWS | Woodland | 71 | Clark County |
| Vantage Water System | WA5391250 | CWS | Vantage | 405 | Kittitas County |
| Vaughan Pumps | WA53AA938 | NTNCWS | Port Orchard | 85 | Grays Harbor County |
| Vaughn Elementary School | WA5324761 | NTNCWS | Gig Harbor | 450 | Pierce County |
| Vel View Water Dist 13 | WA5391445 | CWS | Spokane | 77 | Spokane County |
| Verdan Anderson Hill | WA5391470 | CWS | Tacoma | 37 | Kitsap County |
| Veterans Affair Med Ctr Dept Of | WA5390542 | CWS | Yakima | 785 | Walla Walla County |
| Victor Water Association | WA5391650 | CWS | Bellingham | 43 | Whatcom County |
| View Ranch Estates Water Assn | WA5301567 | CWS | Chehalis | 141 | Lewis County |
| View Ridge Heights | WA5391845 | CWS | Union | 271 | Mason County |
| View Royal Water System | WA5328494 | CWS | Puyallup | 2,069 | Pierce County |
| Viewcrest Beach | WA5391900 | CWS | Union | 40 | Mason County |
| Viewcrest Water System | WA5391902 | CWS | Mt Vernon | 39 | Island County |
| Viewside Community | WA5391850 | CWS | Poulsbo | 118 | Kitsap County |
| Viking Road Water System | WA5319208 | CWS | Moses Lake | 88 | Grant County |
| Viking Village Mobile Home Park | WA5391908 | CWS | Woodland | 25 | Cowlitz County, Wahkiakum County |
| Vikings West Mobile Home | WA5391910 | CWS | Aberdeen | 71 | Grays Harbor County |
| Vineyard Cove Corporation | WA5391917 | CWS | Port Orchard | 44 | Mason County |
| Vineyard The 696 | WA5305290 | CWS | Lacey | 130 | Thurston County |
| Vinson S Villa Mhp/Roy Wye Inn | WA5391925 | CWS | Gig Harbor | 40 | Pierce County |
| Vista By The Sea | WA5391930 | CWS | Port Orchard | 50 | Thurston County |
| Vista Del Rio Mobile Home Park | WA5306044 | CWS | Vancouver | 352 | Clark County |
| Vista Dunes Water Association | WA5391935 | CWS | Raymond | 45 | Pacific County |
| Vista Glen | WA5364340 | CWS | Port Orchard | 58 | Snohomish County |
| Vista Vue Water Users Assn | WA5320226 | CWS | Tonasket | 60 | Okanogan County |
| Vistaire Water System | WA5357414 | CWS | Clinton | 647 | Island County |
| Vistas Inc | WA5358144 | CWS | Sequim | 241 | Clallam County |
| Vosper Place Subdivision | 105338111 | CWS | Oakville | 68 | Lewis County |
| Vuecrest | WA5318637 | CWS | Union | 191 | Mason County |
| W&B Waterworks 1 | WA5346670 | CWS | Freeland | 1,112 | Island County |
| Wa He Lut Indian School | 105318112 | NTNCWS | Washington | 175 | |
| Wagon Wheel | WA5392070 | CWS | Coupeville | 150 | Island County |
| Wagon Wheel Estate | WA5392062 | CWS | Connell | 25 | Grant County |
| Wagon Wheel Mhp | WA5308131 | CWS | East Wenatchee | 86 | Grant County |
| Wagon Wheels Cafe | WA5392059 | NTNCWS | Winthrop | 69 | Okanogan County |
| Wahl Water Assoc | WA5392150 | CWS | Bellingham | 165 | Whatcom County |
| Waitsburg City Of | WA5392250 | CWS | Waitsburg | 1,817 | Walla Walla County |
| Walczak 620 | WA5392350 | CWS | Lacey | 256 | King County |
| Walden Water | WA5343887 | CWS | Tacoma | 34 | Kitsap County |
| Walla Walla Airport | WA5392430 | NTNCWS | Walla Walla | 280 | Walla Walla County |
| Walla Walla River Packing & Storage | WA53AA597 | NTNCWS | Walla Walla | 75 | Walla Walla County |
| Walla Walla University | WA5392470 | CWS | Walla Walla | 1,273 | Walla Walla County |
| Wallula Dodd Water System | WA53AB183 | NTNCWS | Walla Walla | 1,757 | Walla Walla County |
| Wallula Water District | WA5392600 | CWS | College Place | 200 | Walla Walla County |
| Walter Walker Water Works | WA5320276 | CWS | Tacoma | 42 | King County, Kittitas County |
| Wanapum Indian Village | WA5329075 | CWS | Beverly | 60 | Yakima County |
| Wanapum Maintenance Center | WA5329078 | NTNCWS | Beverly | 70 | Grant County |
| Wanapum Powerplant | WA5329080 | NTNCWS | Beverly | 126 | Grant County |
| Wanapum Village | WA5329082 | CWS | Selah | 305 | Grant County, Kittitas County |
| Wandering Creek Homeowners Assoc | WA5323486 | CWS | Bothell | 457 | Snohomish County |
| Wapato Headstart | 105300139 | NTNCWS | Toppenish | 95 | Yakima County |
| Warden Hutterian Brethren 1 | WA5392829 | CWS | Warden | 171 | Adams County |
| Warm Beach Conference Grounds | WA5392950 | CWS | Mt Vernon | 1,190 | Snohomish County |
| Warner Flats Domestic Water Co Inc | WA5306073 | CWS | Cashmere | 100 | Chelan County |
| Washington Beef Llc | 105393061 | NTNCWS | Toppenish | 1,025 | |
| Washington Beef Llc | WA5393061 | NTNCWS | Toppenish | 1,025 | Yakima County |
| Washington Corrections Center | WA5393063 | CWS | Shelton | 2,223 | Mason County |
| Washington Land Yacht Harbor | WA5393085 | CWS | Port Orchard | 340 | Thurston County |
| Washington Soldiers Home Colony | WA5364700 | CWS | Port Orchard | 643 | Pierce County |
| Washington State Corrections-Women | WA5369945 | CWS | Gig Harbor | 1,205 | Pierce County |
| Washtucna Water Department | WA5393450 | CWS | Washtucna | 250 | Adams County |
| Waterloo Acres Community Water Sys | WA5393580 | CWS | Oak Harbor | 125 | Island County |
| Waterville Town Of | WA5393600 | CWS | Waterville | 1,140 | Douglas County |
| Wauna Easley | WA5339740 | CWS | Gig Harbor | 66 | Kitsap County, Pierce County |
| Waverly Town Of | WA5393820 | CWS | Waverly | 120 | Spokane County |
| Waynes Ridge Water Assoc | WA5393909 | CWS | Coupeville | 108 | Island County |
| Wayside Village | WA5305704 | CWS | Chehalis | 60 | Thurston County |
| Weatherswood Vista Water District | WA5393950 | CWS | Gig Harbor | 210 | Pierce County |
| Webster Hill 610 | WA5359875 | CWS | Lacey | 55 | Pierce County |
| Wee Wun | 105338109 | CWS | Suquamish | 75 | |
| Weiler-Martin Tracts Water Assn | WA5394110 | CWS | Quincy | 1,163 | Grant County |
| Weimer Road | WA53AB859 | NTNCWS | Tonasket | 76 | Douglas County |
| Welchs | WA5316331 | NTNCWS | Kennewick | 180 | Benton County |
| Welchs Water Association | WA5394170 | CWS | Port Orchard | 69 | King County |
| Wellpinit | 105300022 | CWS | Wellpinit | 525 | Stevens County |
| Wellpinit School | 105300156 | NTNCWS | Wellpinit | 473 | |
| Wells Hydroelectric Project | WA5394220 | NTNCWS | Tonasket | 56 | Chelan County |
| Wells Water Association | WA5394200 | CWS | Auburn | 39 | King County |
| West 15 Domestic Water Assn | WA5394650 | CWS | Othello | 150 | Franklin County |
| West Beach Road Association | WA5317970 | CWS | Coupeville | 37 | Island County |
| West Cashmere Water System | WA5394475 | CWS | Cashmere | 63 | Chelan County |
| West Deer Lake #1 | WA5300615 | CWS | Langley | 24 | Island County |
| West Kitsap | WA5308367 | CWS | Poulsbo | 2,248 | Kitsap County |
| West Mesa Domestic Water Assn | WA5394830 | CWS | Othello | 316 | Franklin County |
| West Prairie Village | WA5310614 | CWS | Spokane | 375 | Spokane County |
| West Ridge Water System | WA5394942 | CWS | Coupeville | 275 | Island County |
| West Side Mobile Court | WA5394910 | CWS | Othello | 80 | Adams County |
| West Sound Academy | WA53AB639 | NTNCWS | Port Orchard | 120 | Kitsap County |
| West Sound Water Association | WA5345014 | CWS | Eastsound | 206 | San Juan County |
| West View Apartments Water System | WA5305570 | CWS | Coupeville | 54 | Island County |
| West Wynd | WA5394930 | CWS | Port Orchard | 87 | Pierce County |
| Westbourne Acres | WA5395047 | CWS | College Place | 94 | Walla Walla County |
| Westbridge Estates Water Assn | WA5394935 | CWS | Port Orchard | 98 | Pierce County |
| Western Airpark | WA5395057 | CWS | Shelton | 78 | Thurston County |
| Western Ranchettes Inc. | WA5395123 | CWS | Black Diamond | 250 | Pierce County |
| Western State Hospital | WA5395150 | CWS | Port Orchard | 2,857 | Pierce County |
| Western Stavis Water Sys Ii & Iii | WA5301668 | CWS | Poulsbo | 60 | Kitsap County |
| Western Wahkiakum | WA5395167 | CWS | Cathlamet | 791 | Pacific County, Wahkiakum County |
| Westmont Acres | WA5395240 | CWS | Soap Lake | 206 | Grant County |
| Westshore Acres Community Water | WA5304452 | NTNCWS | Moses Lake | 29 | Grant County |
| Westshore Water Company | WA5356143 | CWS | Moses Lake | 153 | Grant County |
| Westside Water Assn | WA5394950 | CWS | Vashion Island | 562 | King County |
| Westview Community Association | WA5395375 | CWS | Oak Harbor | 43 | Island County |
| Weyerhaeuser Elementary School | WA5359103 | NTNCWS | Port Orchard | 362 | Pierce County |
| Weyerhaeuser Vail Shop | WA5395610 | NTNCWS | Rainier | 86 | Thurston County |
| Whatcom County Water Dist #2 | WA5395700 | CWS | Lynden | 1,353 | Whatcom County |
| Whatcom County Water Dist #7 | WA5395900 | CWS | Bellingham | 1,410 | Whatcom County |
| Wheel Estates Park | WA5395942 | CWS | Freeland | 95 | Island County |
| Whidbey Highlands Water Assoc | WA5396050 | CWS | Coupeville | 62 | Island County |
| Whidbey Institute | WA5305235 | NTNCWS | Port Orchard | 73 | Island County |
| Whidbey Shores Water System | WA5396070 | CWS | Coupeville | 262 | Island County |
| Whidbey West Water Assoc. | WA5336314 | CWS | Coupeville | 415 | Island County |
| Whiskey Hollow 670 | WA5320692 | CWS | Lacey | 45 | Pierce County |
| Whispering Cedars | 105300120 | CWS | Deming | 25 | Whatcom County |
| Whispering Firs At Firetrail | WA53AD238 | CWS | Mt Vernon | 51 | Snohomish County |
| Whispering Pines | WA5342948 | CWS | Port Orchard | 100 | Chelan County, Yakima County |
| Whispering Pines Homeowners Coop | WA5388215 | CWS | Coupeville | 116 | Island County |
| Whispering Rock Farmworker Housing | WA53AC660 | CWS | Wenatchee | 92 | Grant County |
| Whispering Woods Home Park | WA5396095 | CWS | Napavine | 125 | Thurston County |
| White Bluff - Jpra | WA5310634 | NTNCWS | Fairchild Afb | 165 | Spokane County |
| White Bluff Water Association | WA5396100 | CWS | Kennewick | 386 | Franklin County |
| White Pass Company Inc | WA5396175 | NTNCWS | Naches | 2,094 | Lewis County |
| White Swan | 105300026 | CWS | Toppenish | 900 | Yakima County |
| Whiteman Cove Water District | WA5396527 | CWS | Gig Harbor | 53 | Pierce County |
| Whiteside Homeowners Association | WA5307581 | CWS | Mt Vernon | 90 | Snohomish County |
| Whitestone Pears | WA5307319 | NTNCWS | Wenatchee | 62 | Okanogan County |
| Whitstran Elementary School | WA5396535 | NTNCWS | Yakima | 280 | Benton County |
| Whitstran Heights Water Association | WA5396550 | CWS | Yakima | 65 | Benton County |
| Whittlesey Water System | WA53AD599 | CWS | Yakima | 31 | Yakima County |
| Whitworth University | WA5396580 | CWS | Spokane | 1,200 | Spokane County |
| Wickersham Water Association | WA5396700 | CWS | Acme | 98 | Whatcom County |
| Wicks Lake Ranches | WA5396728 | CWS | Tacoma | 615 | Kitsap County |
| Widarama Beach Water Rights Assn. | WA5396750 | CWS | Mt Vernon | 85 | Island County |
| Wilbur Town Of | WA5396800 | CWS | Spokane | 1,040 | Lincoln County |
| Wilcox Farms Inc | WA5396825 | NTNCWS | Roy | 152 | Pierce County |
| Wildaire Estates | WA5396850 | CWS | Chehalis | 146 | Thurston County |
| Wilderness Glen 263 | WA5331226 | CWS | Lacey | 75 | Pierce County |
| Wilderness Ridge Community Club | WA5396876 | CWS | Coupeville | 664 | Snohomish County |
| Wilderness Rim Association | WA5396878 | CWS | Falls City | 1,867 | King County |
| Wilderwood Hoa | WA5347451 | CWS | Port Orchard | 98 | Kitsap County |
| Wildes Grove Community Water Sys | WA5326911 | CWS | Coupeville | 33 | Island County |
| Wildlife Acres Water Association | WA5396882 | CWS | Maple Falls | 46 | Skagit County |
| Wildrose Village | WA5396891 | CWS | Colbert | 30 | Spokane County |
| Wildwood 2 And 3 | WA5396883 | CWS | Ronald | 93 | Kittitas County |
| Wilgus Housing Water System | WA53AB933 | CWS | Grandview | 121 | Benton County, Yakima County |
| Wilkeson Water Department | WA5396950 | CWS | Wilkeson | 1,071 | Pierce County |
| Wilkshire Lane Water District Inc | WA5396930 | CWS | Arlington | 460 | Snohomish County |
| Willamette Egg Farms - Moses Lake | WA5301536 | NTNCWS | Waverly | 44 | Grant County |
| Willapa Valley Water District | WA5397100 | CWS | Raymond | 2,425 | Pacific County |
| Willard | WA5315663 | CWS | Willard | 40 | Skamania County |
| Willard National Fish Hatchery | WA53FW965 | NTNCWS | Underwood | 50 | Skamania County |
| Willeys Lake Terrace Water Assn | WA5397110 | CWS | Lynden | 180 | Whatcom County |
| Williams Lake Beach Club | WA5309280 | CWS | Tekoa | 45 | Spokane County |
| Williams Lake Road Subdivision | WA5397123 | CWS | Colville | 40 | Stevens County |
| Willow Tree Park | WA5391912 | CWS | Yakima | 176 | Yakima County |
| Wilma Port Of | WA5397300 | NTNCWS | Clarkston | 108 | Whitman County |
| Wilson Creek Water Dept Town Of | WA5397400 | CWS | Quincy | 386 | Grant County |
| Wilson Point | WA5304582 | CWS | Raymond | 54 | Pacific County |
| Winchester Farmworker - Cfp | WA53AD160 | CWS | Wenatchee | 96 | Grant County |
| Winchester Heights | WA5330691 | CWS | Puyallup | 80 | Pierce County |
| Winchester Mobile Homes Water | WA5319571 | CWS | Spanaway | 350 | Pierce County |
| Winchester West Farmworker Housing | WA53AD611 | CWS | Wenatchee | 100 | Grant County |
| Wind River Admin Site | WA53FS987 | NTNCWS | Woodland | 38 | Skamania County |
| Wind River Business Park | WA53AD455 | NTNCWS | Woodland | 65 | Skamania County |
| Wind River Community | WA5320029 | CWS | Woodland | 44 | Skamania County |
| Winddrift Well | WA5301023 | CWS | Tacoma | 53 | Kitsap County |
| Windmill Heights Comm Club | WA5397440 | CWS | Freeland | 45 | Island County |
| Windolph | WA5397450 | CWS | Port Orchard | 75 | Thurston County |
| Winlock City Of | WA5397500 | CWS | Winlock | 3,502 | Lewis County |
| Winlock Fibre Llc | WA5306991 | NTNCWS | Napavine | 34 | Lewis County |
| Winlock High School | WA5356555 | NTNCWS | Winlock | 400 | Lewis County |
| Winlock Waters 2 | WA5307925 | CWS | Napavine | 25 | Lewis County |
| Winston Creek Rv Park | WA5358780 | CWS | Napavine | 50 | Lewis County |
| Winthrop Town Of | WA5397750 | CWS | Winthrop | 1,350 | Okanogan County |
| Wishram Water System | WA5397950 | CWS | Goldendale | 599 | Klickitat County |
| Withrow Water Works | WA5398000 | CWS | Tonasket | 60 | Douglas County |
| Wolf Creek Property Owners Assn | WA5311476 | CWS | Tonasket | 71 | Okanogan County |
| Wolf Point | 105300051 | CWS | Wapato | 125 | Yakima County |
| Wolfe Water Association | WA5398045 | CWS | Yakima | 70 | Yakima County |
| Wollochet Harbor Club Inc | WA5398075 | CWS | Gig Harbor | 221 | Pierce County |
| Wonderland Water Company | WA5398128 | CWS | Union | 82 | Mason County |
| Woodard Place | WA5301898 | CWS | Olympia | 94 | Thurston County |
| Woodbridge Gardens | WA5306519 | NTNCWS | Lodi | 60 | Lewis County |
| Woodglen Prd Water System | WA5306529 | CWS | Coupeville | 40 | Island County |
| Woodland Estates | WA5398183 | CWS | Coupeville | 106 | Island County |
| Woodland Heights | WA5323581 | CWS | Snohomish | 108 | Clallam County, King County |
| Woodland Heights | WA5398182 | CWS | Sequim | 105 | Clallam County |
| Woodland Manor | WA5398184 | CWS | Union | 192 | Mason County |
| Woodland Mhc Llc | WA5320469 | CWS | Port Orchard | 209 | Clark County |
| Woodland Park Mobil Court | WA5398189 | CWS | Yakima | 75 | Yakima County |
| Woodland Park Trailer Court | WA5398190 | CWS | Spokane | 38 | Spokane County |
| Woodland Park Utility Assn | WA5398187 | CWS | Grapeview | 68 | Thurston County |
| Woods Creek Water District | WA5398230 | CWS | Monroe | 25 | Snohomish County |
| Wsu Iarec - Prosser | WA5393195 | NTNCWS | Prosser | 224 | Benton County |
| Wyckoff Farms | WA5398673 | CWS | Grandview | 131 | Benton County, Yakima County |
| Wye Lake Acreages | WA5398684 | CWS | Port Orchard | 175 | Kitsap County |
| Y-Squalicum Water Assn | WA5399550 | CWS | Lynden | 260 | Whatcom County |
| Yacolt | WA5399000 | CWS | Vancouver | 3,034 | Clark County |
| Yak Co - Buena Water System | WA5334301 | CWS | Yakima | 952 | Yakima County |
| Yak Co - Crewport | WA5316242 | CWS | Yakima | 192 | Yakima County |
| Yak Co - Gala Estates Water System | WA5323280 | CWS | Yakima | 119 | Yakima County |
| Yakima Golding Farms 1 | WA5399110 | CWS | Toppenish | 90 | Yakima County |
| Yakima Training Center - Mprc | WA5307035 | NTNCWS | Yakima | 45 | Kittitas County |
| Yakima Training Center - Mtef | WA5307029 | NTNCWS | Yakima | 30 | Yakima County |
| Yakima Training Center - Pomona | WA5399104 | NTNCWS | Yakima | 280 | Yakima County |
| Yale Elementary School | WA5337101 | NTNCWS | Woodland | 50 | Cowlitz County |
| Zebras Aqueous Substance | WA5361131 | NTNCWS | Port Orchard | 526 | Thurston County |
| Zillah City Of | WA5399800 | CWS | Zillah | 3,518 | Yakima County |
| Zirkle - Paterson Ranch | WA53AC500 | NTNCWS | Yakima | 374 | Benton County |
| Zirkle-Chief Mattawa Ranch | WA53AD237 | NTNCWS | Yakima | 25 | Grant County |