Sammamish, WA · King County

SAMMAMISH PLATEAU WATER & SEWER Water System

Current status

No open violations on record as of July 4, 2026.

This system's next federally required Consumer Confidence Report is due July 1, 2027, under the EPA's revised reporting rule.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 2026. This is a record-keeping and public-information tool — it does not replace Washington’s official records. Always confirm current status with Washington before making decisions based on this information.

System facts

System ID (PWSID): WA5340900
System type: Community Water System
Population served: 79,362
Service connections: 24,792
Ownership: local government
Water source: surface water (rivers, lakes, or reservoirs)

Violation history

Monitoring, Regular
—
Nitrate
January 1, 2009 – December 31, 2009
Resolved
Monitoring, Regular
—
Nitrate
January 1, 2009 – December 31, 2009
Resolved
Monitoring, Regular
—
Diquat
April 1, 2008 – June 30, 2008
Archived
Monitoring, Regular
—
ETHYLENE DIBROMIDE
April 1, 2008 – June 30, 2008
Archived
Monitoring, Regular
—
1,2-DIBROMO-3-CHLOROPROPANE
April 1, 2008 – June 30, 2008
Archived
Monitoring, Regular
—
Heptachlor epoxide
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Endrin
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
BHC-GAMMA
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Methoxychlor
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Toxaphene
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Di(2-ethylhexyl) adipate
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Simazine
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Di(2-ethylhexyl) phthalate
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Hexachlorocyclopentadiene
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Atrazine
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
LASSO
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Heptachlor
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
HEXACHLOROBENZENE
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Benzo(a)pyrene
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Pentachlorophenol
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Chlordane
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Dalapon
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Picloram
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Dinoseb
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
2,4,5-TP
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
Pentachlorophenol
January 1, 2008 – December 31, 2010
Archived
Monitoring, Regular
—
ETHYLENE DIBROMIDE
October 1, 2007 – December 31, 2007
Resolved
Monitoring, Regular
—
Diquat
October 1, 2007 – December 31, 2007
Resolved
Monitoring, Regular
—
1,2-DIBROMO-3-CHLOROPROPANE
October 1, 2007 – December 31, 2007
Resolved
Monitoring, Regular
—
Diquat
July 1, 2007 – September 30, 2007
Resolved
Monitoring, Regular
—
ETHYLENE DIBROMIDE
July 1, 2007 – September 30, 2007
Resolved
Monitoring, Regular
—
1,2-DIBROMO-3-CHLOROPROPANE
July 1, 2007 – September 30, 2007
Resolved
Monitoring, Regular
—
Mercury
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Nickel
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Selenium
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Antimony, Total
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Beryllium, Total
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Thallium, Total
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Fluoride
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Arsenic
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Barium
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Cadmium
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
Chromium
January 1, 2005 – December 31, 2007
Archived
Monitoring, Regular
—
CYANIDE
January 1, 2005 – December 31, 2007
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
January 1, 2004 – January 31, 2004
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
August 1, 2000 – August 31, 2000
Archived
Monitoring, Repeat Major (TCR)
—
Coliform (TCR)
June 1, 1995 – June 30, 1995
Archived
Monitoring, Routine Minor (TCR)
—
Coliform (TCR)
November 1, 1991 – November 30, 1991
Archived
Monitoring, Regular
—
Gross Alpha, Excl. Radon and U
October 1, 1979 – October 31, 1979
Archived

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Period	Violation	Contaminant / rule	Health-based	Status
January 1, 2009 – December 31, 2009	Monitoring, Regular	Nitrate	—	Resolved
January 1, 2009 – December 31, 2009	Monitoring, Regular	Nitrate	—	Resolved
April 1, 2008 – June 30, 2008	Monitoring, Regular	Diquat	—	Archived
April 1, 2008 – June 30, 2008	Monitoring, Regular	ETHYLENE DIBROMIDE	—	Archived
April 1, 2008 – June 30, 2008	Monitoring, Regular	1,2-DIBROMO-3-CHLOROPROPANE	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Heptachlor epoxide	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Endrin	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	BHC-GAMMA	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Methoxychlor	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Toxaphene	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Di(2-ethylhexyl) adipate	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Simazine	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Di(2-ethylhexyl) phthalate	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Hexachlorocyclopentadiene	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Atrazine	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	LASSO	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Heptachlor	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	HEXACHLOROBENZENE	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Benzo(a)pyrene	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Pentachlorophenol	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Chlordane	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Dalapon	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Picloram	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Dinoseb	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	2,4,5-TP	—	Archived
January 1, 2008 – December 31, 2010	Monitoring, Regular	Pentachlorophenol	—	Archived
October 1, 2007 – December 31, 2007	Monitoring, Regular	ETHYLENE DIBROMIDE	—	Resolved
October 1, 2007 – December 31, 2007	Monitoring, Regular	Diquat	—	Resolved
October 1, 2007 – December 31, 2007	Monitoring, Regular	1,2-DIBROMO-3-CHLOROPROPANE	—	Resolved
July 1, 2007 – September 30, 2007	Monitoring, Regular	Diquat	—	Resolved
July 1, 2007 – September 30, 2007	Monitoring, Regular	ETHYLENE DIBROMIDE	—	Resolved
July 1, 2007 – September 30, 2007	Monitoring, Regular	1,2-DIBROMO-3-CHLOROPROPANE	—	Resolved
January 1, 2005 – December 31, 2007	Monitoring, Regular	Mercury	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Nickel	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Selenium	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Antimony, Total	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Beryllium, Total	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Thallium, Total	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Fluoride	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Arsenic	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Barium	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Cadmium	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	Chromium	—	Archived
January 1, 2005 – December 31, 2007	Monitoring, Regular	CYANIDE	—	Archived
January 1, 2004 – January 31, 2004	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
August 1, 2000 – August 31, 2000	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
June 1, 1995 – June 30, 1995	Monitoring, Repeat Major (TCR)	Coliform (TCR)	—	Archived
November 1, 1991 – November 30, 1991	Monitoring, Routine Minor (TCR)	Coliform (TCR)	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Gross Alpha, Excl. Radon and U	—	Archived

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Enforcement actions

February 24, 2010State Compliance achieved1 linked violation
February 24, 2010State Compliance achieved1 linked violation
January 1, 2008State Compliance achieved82 linked violations
January 1, 2008State Compliance achieved179 linked violations

Contact

SAMMAMISH PLATEAU WATER & SEWER

Phone not on record

Sammamish, WA 98075