North Collin Sud, TX
Lead detected, under the action levels
Latest 90th-percentile lead: 1.93 ppb (monitoring period 2023-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
About North Collin Sud
North Collin Sud serves about 10,716 people through 3,572 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Collin County, Texas. EPA system ID: TX0430055; phone on file: 972-837-2331. They can tell you what your service line is made of and whether they pay to replace it.
North Collin Sud's lead record
That is up 1.93 ppb from 0 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for North Collin Sud is 1.93 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.93 ppb |
| 2022 | 0 (not detected) |
| 2021 | 1.1 ppb |
| 2020 | 0 (not detected) |
| 2019 | 1.3 ppb |
| 2018 | 1.5 ppb |
| 2017 | 1.5 ppb |
| 2016 | 1.3 ppb |
How North Collin Sud compares
Of the 4,447 Texas systems with a lead result, the median latest reading is 0.28 ppb; 15 are over 15 ppb right now and 202 have gone over at some point. North Collin Sud's 1.93 ppb sits at the 81st percentile in Texas and the 69th nationally (higher means more lead).
Other water systems in Collin County
34 other systems share Collin County; 5 of them have a higher latest lead result than North Collin Sud. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Plano | 292,059 | 1.68 ppb |
| City Of Frisco | 231,910 | 1.4 ppb |
| City Of Mckinney | 224,043 | 1.65 ppb |
| City Of Allen | 113,746 | 1.7 ppb |
| City Of Celina | 52,701 | 1.98 ppb |
| City Of Wylie | 48,393 | 1.03 ppb |
| Town Of Prosper | 42,598 | 1.98 ppb |
| City Of Princeton | 37,019 | 1.76 ppb |
| City Of Melissa | 26,234 | 1.43 ppb |
| Culleoka Wsc | 24,615 | 0 (not detected) |
Next steps for Melissa, TX
Test your own tap with a certified lab first-draw sample; Melissa, TX may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask North Collin Sud whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.