Collin County Water Quality
Collin County, Texas
Water Grade
A
Water Score
70.8
Violations
8
State Rank
#16
of 254 (1 = best)
EPA SDWIS Compliance
Drinking Water Quality
Water Quality Grade
A
Based on EPA compliance history and violation data
Water Score
70.8/100
Higher = better quality
Health Violations
8
Health-based violations
Violation Rate
0.6%
Systems with violations
Water Advisory: Collin County
Water Verdict
Collin County receives a good water quality assessment with a grade of A and a score of 70.8 out of 100. While the water supply is generally safe, occasional monitoring gaps or minor contaminant detections may occur.
Violation Context
Collin County has recorded 8 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 0.6 violations per 1,000 residents, this rate is relatively low compared to many U.S. counties.
Consumer Guidance
Tap water in Collin County is generally safe to drink based on available data. Residents should still review their utility's annual Consumer Confidence Report for transparency on detected contaminants. With 8 recorded health violations, staying informed about utility communications and boil-water notices is especially important. For long-term peace of mind, request your utility's latest Consumer Confidence Report and consider independent water testing if you have specific health concerns.
Regional Context
Collin County has better water quality than the average county in Texas. Its water score is 40.4 points higher than the state average, indicating stronger water system performance relative to neighboring counties.
Past 5 years
Water Quality Monitoring
Monitoring Sites
93
Active in the past 5 years
Measurements Recorded
62K
62,414 total readings
Most Measured
- Physical
- Inorganics, Major, Non-metals
- Nutrient
Categories measured most frequently
Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).
Live USGS Streamgage
River & Stream Conditions
Current Discharge
416cfs
May 14, 7:00 PM UTC
vs Long-Term Average
128%
Above typicalPrimary Streamgage
E Fk Trinity Rv nr Lavon, TX
- USGS site
- 08061000
- Drainage area
- 773 sq mi
- Long-term mean
- 325 cfs
One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges — this view summarizes the primary one. The long-term mean is the full-record annual average; "% of typical" compares the latest reading against that average.
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Frequently Asked Questions
What is the water quality in Collin County, Texas?
Are there any water violations in Collin County?
How much water-quality monitoring happens in Collin County?
What's happening with rivers in Collin County right now?
How does Collin County water compare to the Texas average?
Is tap water safe to drink in Collin County?
Why does Collin County have so many water violations?
How does Collin County rank for water quality in Texas?
Counties with Similar Water Quality
Data Sources
Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.
Water-quality monitoring counts from the EPA Water Quality Portal (WQP) — federated USGS, EPA, and state agency sampling records over a rolling 5-year window.
Live streamflow from the USGS National Water Information System (NWIS) — continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.
Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.