Mountlake Terrace, WA · Snohomish County
MOUNTLAKE TERRACE CITY OF Water System
Consumer Confidence Report status
MOUNTLAKE TERRACE CITY OF must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.
As of August 1, 2026, EPA's federal records show no open violations for MOUNTLAKE TERRACE CITY OF.
Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 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)
- WA5357250
- System type
- Community Water System
- Population served
- 26,402
- Service connections
- 9,290
- Ownership
- local government
- Water source
- surface water (rivers, lakes, or reservoirs)
MOUNTLAKE TERRACE CITY OF is one of 111 community water systems in Washington in the 10,001 to 100,000 people size category, serving 26,402 people from surface water.
As of August 1, 2026, its federal record holds 10 entries between 2011 and 2024, all of which EPA lists as closed.
Of the 10, 3 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves the Consumer Confidence Rule and the Stage 2 Disinfectants and Disinfection Byproducts Rule.
Violation history
Consumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2024 – February 20, 2025
ResolvedMonitoring and Reporting (DBP)
—Total Haloacetic Acids (HAA5)
January 1, 2020 – March 31, 2020
ResolvedMonitoring and Reporting (DBP)
—TTHM
January 1, 2020 – March 31, 2020
ResolvedMonitoring and Reporting (DBP)
—TTHM
January 1, 2019 – March 31, 2019
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2017 – January 31, 2018
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2015 – September 15, 2015
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2014 – October 8, 2014
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2013 – September 13, 2013
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2012 – September 28, 2012
ResolvedConsumer Confidence Report Complete Failure to Report
—Consumer Confidence Rule
July 1, 2011 – August 23, 2011
Resolved
Resolved addressed and confirmed by the state
| Period | Violation | Contaminant / rule | Health-based | Status |
|---|---|---|---|---|
| July 1, 2024 – February 20, 2025 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| January 1, 2020 – March 31, 2020 | Monitoring and Reporting (DBP) | Total Haloacetic Acids (HAA5) | — | Resolved |
| January 1, 2020 – March 31, 2020 | Monitoring and Reporting (DBP) | TTHM | — | Resolved |
| January 1, 2019 – March 31, 2019 | Monitoring and Reporting (DBP) | TTHM | — | Resolved |
| July 1, 2017 – January 31, 2018 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| July 1, 2015 – September 15, 2015 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| July 1, 2014 – October 8, 2014 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| July 1, 2013 – September 13, 2013 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| July 1, 2012 – September 28, 2012 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
| July 1, 2011 – August 23, 2011 | Consumer Confidence Report Complete Failure to Report | Consumer Confidence Rule | — | Resolved |
Resolved addressed and confirmed by the state
Enforcement actions
- February 20, 2025State Compliance achieved1 linked violation
- June 23, 2020State Compliance achieved1 linked violation
- June 23, 2020State Compliance achieved1 linked violation
- June 11, 2019State Compliance achieved1 linked violation
- January 31, 2018State Compliance achieved1 linked violation
- October 19, 2016State Compliance achieved1 linked violation
- September 15, 2015State Compliance achieved1 linked violation
- October 8, 2014State Compliance achieved1 linked violation
- September 13, 2013State Compliance achieved1 linked violation
- September 28, 2012State Compliance achieved1 linked violation
- August 23, 2011State Compliance achieved1 linked violation
- September 30, 1992State Violation/Reminder Notice1 linked violation
Common questions
Is MOUNTLAKE TERRACE CITY OF required to publish a Consumer Confidence Report?
- Yes. MOUNTLAKE TERRACE CITY OF is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is MOUNTLAKE TERRACE CITY OF’s next Consumer Confidence Report due?
- MOUNTLAKE TERRACE CITY OF’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does MOUNTLAKE TERRACE CITY OF have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for MOUNTLAKE TERRACE CITY OF.
What is a Consumer Confidence Report?
- A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.
Contact
MOUNTLAKE TERRACE CITY OF
Phone not on record
Mountlake Terrace, WA 98043