Mattawa, WA · Grant County

SENTINEL GAP WATER ASSN 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): WA5376620
System type: Community Water System
Population served: 226
Service connections: 68
Ownership: privately owned
Water source: groundwater (wells)

Violation history

Monitoring, Routine (RTCR)
—
Revised Total Coliform Rule
November 1, 2023 – November 30, 2023
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2023 – September 20, 2023
Resolved
Monitoring, Routine (RTCR)
—
Revised Total Coliform Rule
September 1, 2022 – September 30, 2022
Resolved
Monitoring, Routine (RTCR)
—
Revised Total Coliform Rule
August 1, 2017 – August 31, 2017
Resolved
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
September 1, 2015 – September 30, 2015
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2014 – August 22, 2014
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2012 – October 1, 2012
Resolved
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
June 1, 2006 – June 30, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
May 1, 2006 – May 31, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
April 1, 2006 – April 30, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
March 1, 2006 – March 31, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
February 1, 2006 – February 28, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
January 1, 2006 – January 31, 2006
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
October 1, 2005 – October 31, 2005
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
September 1, 2005 – September 30, 2005
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
August 1, 2005 – August 31, 2005
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
July 1, 2005 – July 31, 2005
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
June 1, 2005 – June 30, 2005
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
May 1, 2005 – May 31, 2005
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
March 1, 2005 – March 31, 2005
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
September 1, 2004 – September 30, 2004
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
May 1, 2004 – May 31, 2004
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
September 1, 2003 – September 30, 2003
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
September 1, 2000 – September 30, 2000
Archived
Monitoring, Routine Major (TCR)
—
Coliform (TCR)
October 1, 1999 – October 31, 1999
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
April 1, 1999 – April 30, 1999
Archived
Monitoring, Repeat Major (TCR)
—
Coliform (TCR)
March 1, 1999 – March 31, 1999
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
February 1, 1999 – February 28, 1999
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
October 1, 1998 – October 31, 1998
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
June 1, 1998 – June 30, 1998
Archived
Monitoring, Regular
—
Fluoride
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Mercury
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Gross Alpha, Excl. Radon and U
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Selenium
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Nitrate
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Arsenic
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Barium
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Cadmium
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Chromium
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
November 1, 2023 – November 30, 2023	Monitoring, Routine (RTCR)	Revised Total Coliform Rule	—	Resolved
July 1, 2023 – September 20, 2023	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
September 1, 2022 – September 30, 2022	Monitoring, Routine (RTCR)	Revised Total Coliform Rule	—	Resolved
August 1, 2017 – August 31, 2017	Monitoring, Routine (RTCR)	Revised Total Coliform Rule	—	Resolved
September 1, 2015 – September 30, 2015	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Resolved
July 1, 2014 – August 22, 2014	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
July 1, 2012 – October 1, 2012	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
June 1, 2006 – June 30, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
May 1, 2006 – May 31, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
April 1, 2006 – April 30, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
March 1, 2006 – March 31, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
February 1, 2006 – February 28, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
January 1, 2006 – January 31, 2006	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
October 1, 2005 – October 31, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
September 1, 2005 – September 30, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
August 1, 2005 – August 31, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
July 1, 2005 – July 31, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
June 1, 2005 – June 30, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
May 1, 2005 – May 31, 2005	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
March 1, 2005 – March 31, 2005	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
September 1, 2004 – September 30, 2004	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
May 1, 2004 – May 31, 2004	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
September 1, 2003 – September 30, 2003	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
September 1, 2000 – September 30, 2000	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
October 1, 1999 – October 31, 1999	Monitoring, Routine Major (TCR)	Coliform (TCR)	—	Archived
April 1, 1999 – April 30, 1999	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
March 1, 1999 – March 31, 1999	Monitoring, Repeat Major (TCR)	Coliform (TCR)	—	Archived
February 1, 1999 – February 28, 1999	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
October 1, 1998 – October 31, 1998	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
June 1, 1998 – June 30, 1998	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Fluoride	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Mercury	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Gross Alpha, Excl. Radon and U	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Selenium	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Nitrate	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Arsenic	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Barium	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Cadmium	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Chromium	—	Archived

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

Enforcement actions

December 12, 2023State Compliance achieved1 linked violation
September 20, 2023State Compliance achieved1 linked violation
October 25, 2022State Compliance achieved1 linked violation
September 11, 2017State Compliance achieved1 linked violation
October 31, 2015State Compliance achieved1 linked violation
August 22, 2014State Compliance achieved1 linked violation
October 1, 2012State Compliance achieved1 linked violation
April 30, 1999State Public Notification received6 linked violations

Contact

SENTINEL GAP WATER ASSN

Phone not on record

Mattawa, WA 99349