Allenspark Wsd, CO
Lead detected, under the action levels
Latest 90th-percentile lead: 1 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 Allenspark Wsd
Allenspark Wsd serves about 340 people through 122 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 surface water, in Boulder County, Colorado. EPA system ID: CO0107115; phone on file: 303-747-0317. They can tell you what your service line is made of and whether they pay to replace it.
Allenspark Wsd's lead record
That is down 3 ppb from 4 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Allenspark Wsd is 15 ppb across 20 monitoring periods, none of them over 15 ppb (2 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1 ppb |
| 2025 | 4 ppb |
| 2025 | 10 ppb |
| 2024 | 6 ppb |
| 2024 | 12 ppb over 10 |
| 2023 | 5 ppb |
| 2023 | 6 ppb |
| 2022 | 4 ppb |
| 2022 | 15 ppb over 10 |
| 2021 | 4 ppb |
| 2021 | 6 ppb |
| 2020 | 7 ppb |
| 2020 | 5.7 ppb |
| 2019 | 2 ppb |
| 2018 | 8 ppb |
| 2018 | 0.5 ppb |
| 2017 | 0.5 ppb |
| 2017 | 2.5 ppb |
| 2016 | 4.2 ppb |
| 2016 | 1.7 ppb |
How Allenspark Wsd compares
Of the 1,025 Colorado systems with a lead result, the median latest reading is 1 ppb; 2 are over 15 ppb right now and 71 have gone over at some point. Allenspark Wsd's 1 ppb sits at the 51st percentile in Colorado and the 53rd nationally (higher means more lead).
Other water systems in Boulder County
39 other systems share Boulder County; 13 of them have a higher latest lead result than Allenspark Wsd. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Boulder City Of | 166,080 | 2 ppb |
| Longmont City Of | 104,178 | 1.6 ppb |
| Erie Town Of | 47,444 | 2.6 ppb |
| Lafayette City Of | 28,700 | 2 ppb |
| Louisville City Of | 20,975 | 0 (not detected) |
| Left Hand Wd | 20,280 | 1 ppb |
| Superior Md No 1 | 17,900 | 0 (not detected) |
| Longs Peak Wd | 3,200 | 2 ppb |
| Lyons Town Of | 2,990 | 0 (not detected) |
| Nederland Town Of | 2,406 | 1 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Allenspark, CO 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 Allenspark Wsd 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. Size matters more than most people expect: small vs large water systems.