Black Diamond, WA · King County
MARIANI WATER SYSTEM INC Water System
Consumer Confidence Report status
MARIANI WATER SYSTEM INC 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 MARIANI WATER SYSTEM INC.
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)
- WA5351675
- System type
- Community Water System
- Population served
- 138
- Service connections
- 49
- Ownership
- privately owned
- Water source
- groundwater (wells)
MARIANI WATER SYSTEM INC is one of 3,227 community water systems in Washington in the 500 or fewer people size category, serving 138 people from groundwater.
As of August 1, 2026, its federal record holds 2 entries between 1993 and 2022, all of which EPA lists as closed. Nothing has been added since 2022.
All 2 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 inorganic chemicals and the Total Coliform Rules.
Violation history
Monitoring, Regular
—Nitrate
January 1, 2022 – December 31, 2022
ResolvedMonitoring, Routine Major (TCR)
—Coliform (TCR)
February 1, 1993 – February 28, 1993
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, 2022 – December 31, 2022 | Monitoring, Regular | Nitrate | — | Resolved |
| February 1, 1993 – February 28, 1993 | Monitoring, Routine Major (TCR) | Coliform (TCR) | — | Archived |
Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)
Enforcement actions
- July 8, 2024State Compliance achieved1 linked violation
Common questions
Is MARIANI WATER SYSTEM INC required to publish a Consumer Confidence Report?
- Yes. MARIANI WATER SYSTEM INC 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 MARIANI WATER SYSTEM INC’s next Consumer Confidence Report due?
- MARIANI WATER SYSTEM INC’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does MARIANI WATER SYSTEM INC have any open drinking water violations on record?
- As of August 1, 2026, EPA's federal records show no open violations for MARIANI WATER SYSTEM INC.
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
MARIANI WATER SYSTEM INC
Phone not on record
Black Diamond, WA 98010