F0/100
Black Diamond Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 2,420 residents · Washington
What's In Black Diamond's Tap Water?
2
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.70 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2017.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
BLACK DIAMOND WATER DEPT
Population Served
2,420
Water Source
Groundwater
System ID
WA5307220
Frequently Asked Questions About Black Diamond Water
Is Black Diamond tap water safe to drink?
Black Diamond, Washington tap water receives a grade of F (0/100), which is considered failing. 1 contaminant(s) exceed EPA maximum contaminant levels and 164 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Black Diamond's water?
Of the 2 contaminants tested in Black Diamond's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Black Diamond have any water quality violations?
Yes, Black Diamond has 164 EPA violation(s) on record, with the most recent in 2017. Violation types include Other, MR, MCL. 6 of these are health-based violations, which are the most serious category.
Do I need a water filter in Black Diamond?
Based on EPA data, using a water filter in Black Diamond is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Black Diamond's tap water come from?
Black Diamond's drinking water is sourced from groundwater and supplied by BLACK DIAMOND WATER DEPT. The system serves approximately 2,420 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Black Diamond's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Black Diamond's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Black Diamond's water compare to other cities in Washington?
Black Diamond's water quality score of 0/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Washington state page to see how all cities in the state compare.
What should I do if I'm concerned about Black Diamond's water quality?
If you have concerns about Black Diamond's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (BLACK DIAMOND WATER DEPT) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.