Arroyo Seco Mdwca, NM
Lead detected, under the action levels
Latest 90th-percentile lead: 2 ppb (monitoring period 2026-2026). 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.
About Arroyo Seco Mdwca
Arroyo Seco Mdwca serves about 444 people through 182 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Taos County, New Mexico. EPA system ID: NM3505529; phone on file: 575-770-6722. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Arroyo Seco Mdwca's lead record
Against the period ending 2022 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Arroyo Seco Mdwca is 2 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 2 ppb |
| 2022 | 1 ppb |
| 2019 | 2 ppb |
| 2018 | 2 ppb |
Where this result ranks
Of the 504 New Mexico systems with a lead result, the median latest reading is 1.4 ppb; 14 are over 15 ppb right now and 46 have gone over at some point. Arroyo Seco Mdwca's 2 ppb sits at the 62nd percentile in New Mexico and the 71st nationally (higher means more lead).
Neighbouring systems
41 other systems share Taos County; 20 of them have a higher latest lead result than Arroyo Seco Mdwca. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Taos Municipal Water System | 5,528 | 5 ppb |
| Questa Water System | 2,337 | 3.3 ppb |
| El Prado Water & Sanitation District | 1,076 | 7 ppb |
| Village Of Taos Ski Valley | 1,025 | 2.6 ppb |
| Llano Quemado Mdwca | 800 | 2 ppb |
| Ranchos De Taos Mdwca | 750 | 2.7 ppb |
| Talpa Mdwca | 700 | 2.2 ppb |
| Red River Water System | 679 | - |
| Chamisal Mdwca | 550 | 1.7 ppb |
| Penasco Mdwca | 549 | 5.3 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Arroyo Seco, NM 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 Arroyo Seco Mdwca 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.