Cebolla Mdwca, NM
Exceeded the action level in the past
Latest 90th-percentile lead: 3.6 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. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
About Cebolla Mdwca
Cebolla Mdwca serves about 350 people through 116 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 Rio Arriba County, New Mexico. EPA system ID: NM3500921; phone on file: 575-491-7585. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is up 3 ppb from 0.6 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Cebolla Mdwca is 110 ppb across 8 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 3.6 ppb |
| 2025 | 0.6 ppb |
| 2025 | 14 ppb over 10 |
| 2024 | 110 ppb over 15 |
| 2024 | 3.9 ppb |
| 2021 | 2.5 ppb |
| 2019 | 0.8 ppb |
| 2017 | 1.7 ppb |
Against other New Mexico systems
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. Cebolla Mdwca's 3.6 ppb sits at the 80th percentile in New Mexico and the 86th nationally (higher means more lead).
Neighbouring systems
40 other systems share Rio Arriba County; 11 of them have a higher latest lead result than Cebolla Mdwca. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Espanola Water System | 12,012 | 0 (not detected) |
| Chama Water System | 1,573 | 9.1 ppb |
| Agua Sana Wua | 1,514 | 0 (not detected) |
| El Rito Regional Water & Waste Water Asn | 1,200 | 4.1 ppb |
| Greater Chimayo Mdwca | 1,050 | 2.3 ppb |
| Alcalde Mdwca | 927 | 0.56 ppb |
| Chamita Mdwca | 902 | 0 (not detected) |
| Truchas Mdwca | 629 | 3.1 ppb |
| Velarde Mdwca | 543 | 4.1 ppb |
| Dixon Mdwca | 500 | 1.5 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Cebolla, 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 Cebolla 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. Why sampled homes are the worst-case ones is in the guide to reading the number. Why an old exceedance still matters: over the limit before, under it now.