United Water System, LA
Lead detected, under the action levels
Latest 90th-percentile lead: 2 ppb (monitoring period 2024-2026). 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.
Who runs the water here
United Water System serves about 4,446 people through 1,494 service connections, which makes it a medium-sized system under EPA's size classes. It is privately owned and draws groundwater, in St. Martin Parish County, Louisiana. EPA system ID: LA1099009; phone on file: 337-654-1551. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2023 (2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for United Water System is 4 ppb across 13 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 2 ppb |
| 2023 | 2 ppb |
| 2022 | 1 ppb |
| 2021 | 1 ppb |
| 2021 | 1 ppb |
| 2020 | 2 ppb |
| 2019 | 3 ppb |
| 2018 | 3 ppb |
| 2018 | 4 ppb |
| 2017 | 1 ppb |
| 2017 | 2 ppb |
| 2016 | 2 ppb |
| 2016 | 1 ppb |
Where this result ranks
Of the 802 Louisiana systems with a lead result, the median latest reading is 0.72 ppb; 4 are over 15 ppb right now and 30 have gone over at some point. United Water System's 2 ppb sits at the 80th percentile in Louisiana and the 72nd nationally (higher means more lead).
Neighbouring systems
13 other systems share St. Martin Parish County; 5 of them have a higher latest lead result than United Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Village Of Parks Water System | 12,801 | 0 (not detected) |
| Cecilia Water Corporation | 12,420 | 3 ppb |
| Bayou Teche Water Works | 10,137 | 3 ppb |
| City Of Breaux Bridge Water System | 10,098 | 0 (not detected) |
| City Of St. Martinville Water System | 7,263 | 7 ppb |
| Henderson Nina Water System Inc | 6,010 | 4.6 ppb |
| Town Of Arnaudville Water System | 3,957 | 0 (not detected) |
| St Martin Water Works District 3 - Cade | 3,249 | 0 (not detected) |
| St Martin Water District 4 - Catahoula | 3,000 | 1 ppb |
| St Martin Water And Sewer Commission 1 | 2,262 | 1 ppb |
Next steps for Arnaudville, LA
Test your own tap with a certified lab first-draw sample; Arnaudville, LA 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 United Water System whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 2000 ppb (copper action level 1,300 ppb).
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.