Texas
Collin County drinking water quality
35 active public water systems serve 1,269,941 people in Collin County. 18 are compliant, 17 had at least one EPA violation in the past three years, 0 are designated serious violators, and 1 carries a health flag.
Needs attention
Community water systems
35 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
City of Plano |
292,059 | 0 | 0 | |
|
City of Frisco |
231,910 | 0 | 0 | |
|
City of McKinney |
224,043 | 0 | 0 | |
|
City of Allen |
113,746 | 0 | 0 | |
|
City of Celina |
52,701 | 0 | 0 | |
|
City of Wylie |
48,393 | 0 | 0 | |
|
Town of Prosper |
42,598 | 0 | 0 | |
|
City of Princeton |
37,019 | 1 | 0 | |
|
City of Melissa |
26,234 | 0 | 0 | |
|
Culleoka WSC |
24,615 | 3 | 0 | |
|
City of Anna |
23,960 | 4 | 0 | |
|
City of Murphy |
21,082 | 0 | 0 | |
|
East Fork SUD |
17,589 | 0 | 0 | |
|
Bear Creek SUD |
15,822 | 0 | 0 | |
|
Wylie Northeast SUD |
11,430 | 1 | 1 | |
|
Town of Fairview |
11,100 | 0 | 0 | |
|
North Collin SUD |
10,716 | 3 | 2 | |
|
City of Josephine |
9,800 | 1 | 0 | |
|
Copeville SUD |
8,438 | 0 | 0 | |
|
City of Lucas |
8,378 | 0 | 0 | |
|
City of Parker |
6,486 | 0 | 0 | |
|
City of Farmersville |
5,312 | 3 | 1 | |
|
Nevada SUD |
4,218 | 0 | 0 | |
|
Verona SUD |
3,672 | 2 | 1 | |
|
Milligan WSC |
3,364 | 0 | 0 | |
|
North Custer Road Plant |
2,754 | 1 | 0 | |
|
Frognot SUD |
2,643 | 1 | 0 | |
|
Westminster SUD |
2,424 | 1 | 0 | |
|
Desert WSC |
2,091 | 1 | 0 | |
|
Seis Lagos Utility District |
2,037 | 6 | 4 | |
|
City of Blue Ridge |
1,189 | 2 | 1 | |
|
Weston WSC |
1,185 | 5 | 2 | |
|
North Farmersville WSC |
747 | 5 | 1 | |
|
Air Park Estates |
96 | 1 | 1 | |
|
North Texas Mwd Wylie Wtp |
90 | 0 | 0 |
Inactive systems (17, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Texas records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.