Mt Vernon, WA · Whatcom County

DIABLO WTR SYS-SEATTLE CITY LIGHT 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): WA5319200
System type: Community Water System
Population served: 53
Service connections: 41
Ownership: local government
Water source: groundwater (wells)

Violation history

Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2024 – June 22, 2025
Resolved
Monitoring, Regular
—
Nitrate
January 1, 2022 – December 31, 2022
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2021 – November 29, 2021
Resolved
Monitoring and Reporting (DBP)
—
TTHM
January 1, 2021 – December 31, 2023
Resolved
Monitoring and Reporting (DBP)
—
Total Haloacetic Acids (HAA5)
January 1, 2021 – December 31, 2023
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2013 – October 16, 2013
Resolved
Consumer Confidence Report Complete Failure to Report
—
Consumer Confidence Rule
July 1, 2011 – October 31, 2011
Resolved
Follow-up Or Routine LCR Tap M/R
—
Lead and Copper Rule
January 1, 2006 – December 31, 2006
Resolved
Monitoring, Regular
—
Nitrate
January 1, 2004 – December 31, 2004
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
November 1, 1992 – November 30, 1992
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
Monitoring, Regular
—
Fluoride
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Mercury
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Nitrate
October 1, 1979 – October 31, 1979
Archived
Monitoring, Regular
—
Selenium
October 1, 1979 – October 31, 1979
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
July 1, 2024 – June 22, 2025	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
January 1, 2022 – December 31, 2022	Monitoring, Regular	Nitrate	—	Resolved
July 1, 2021 – November 29, 2021	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
January 1, 2021 – December 31, 2023	Monitoring and Reporting (DBP)	TTHM	—	Resolved
January 1, 2021 – December 31, 2023	Monitoring and Reporting (DBP)	Total Haloacetic Acids (HAA5)	—	Resolved
July 1, 2013 – October 16, 2013	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
July 1, 2011 – October 31, 2011	Consumer Confidence Report Complete Failure to Report	Consumer Confidence Rule	—	Resolved
January 1, 2006 – December 31, 2006	Follow-up Or Routine LCR Tap M/R	Lead and Copper Rule	—	Resolved
January 1, 2004 – December 31, 2004	Monitoring, Regular	Nitrate	—	Resolved
November 1, 1992 – November 30, 1992	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	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
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	Nitrate	—	Archived
October 1, 1979 – October 31, 1979	Monitoring, Regular	Selenium	—	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 6, 2026State Compliance achieved1 linked violation
June 22, 2025State Compliance achieved1 linked violation
September 19, 2024State Compliance achieved1 linked violation
September 19, 2024State Compliance achieved1 linked violation
July 18, 2023State Compliance achieved1 linked violation
November 29, 2021State Compliance achieved1 linked violation
October 16, 2013State Compliance achieved1 linked violation
October 31, 2011State Compliance achieved1 linked violation

Contact

DIABLO WTR SYS-SEATTLE CITY LIGHT

Phone not on record

Mt Vernon, WA 98273