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Black Diamond, WA Tap Water Quality 2026

Water quality report for Black Diamond, WA — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Black Diamond's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Black Diamond Water Dept PWSID: WA5307220 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 1.50 ppb, 10% of the action level and no violations are open. PFAS has never been sampled at this system.

B

Black Diamond earns a B for water quality

Graded on violations and lead, with state inspection findings. PFAS not tested.

Lead: 1.50 ppb — 10% of the federal action level
PFAS never sampled at this system
2 violations since 2015, 0 health-based
No violations currently open
Black Diamond's lead level vs. all Washington community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 1.50 ppb — 10% of the federal action level
✓ Lower lead than 75% of Washington utilities
Population Served
3010
~2368 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
2 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
10% of EPA action level
1.50 ppb
Action level: 15 ppb
Copper (Cu)
90th percentile of tap samples. SDWIS reports a copper figure only when a system exceeds the action level, so any value here is an exceedance.
130.8% of EPA action level
1,700 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 1.50 ppb, 10% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home. Copper reached the action level here; a copper figure appears in SDWIS only when a system triggers it.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Consumer Confidence Rule OTHER — — 2017 Resolved
Consumer Confidence Rule OTHER — — 2016 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

2 violations are on record since 2015, of which 0 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Black Diamond Water Dept
PWSID WA5307220
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 3,010
Service connections 2,368
Systems serving this area 3
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Black Diamond tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 1.50 ppb, 10% of the action level.
Does Black Diamond water have PFAS? ▼
This system has never been sampled for PFAS. EPA's national monitoring covered systems serving 3,300 people or more, so no results exist — which is not evidence that none is present.
Who supplies water to Black Diamond? ▼
Black Diamond Water Dept (PWSID WA5307220), one of 3 systems serving this area. Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2023-01-04. No significant deficiencies were recorded.

What Should Black Diamond Residents Do?

1
Read your annual water report
Your supplier publishes a Consumer Confidence Report each July covering the prior year.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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