Thunderbird Wsd, CO
Lead detected, under the action levels
Latest 90th-percentile lead: 5 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.
Thunderbird Wsd at a glance
Thunderbird Wsd serves about 490 people through 176 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 Douglas County, Colorado. EPA system ID: CO0118078; phone on file: 303-688-5962. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Thunderbird Wsd's lead record
That is up 3.5 ppb from 1.5 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Thunderbird Wsd is 5 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 5 ppb |
| 2021 | 1.5 ppb |
| 2020 | 2 ppb |
| 2019 | 0 (not detected) |
| 2018 | 1 ppb |
| 2017 | 2 ppb |
Where this result ranks
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. Thunderbird Wsd's 5 ppb sits at the 92nd percentile in Colorado and the 91st nationally (higher means more lead).
Neighbouring systems
29 other systems share Douglas County; 1 of them has a higher latest lead result than Thunderbird Wsd. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Castle Rock Town Of | 110,298 | 2 ppb |
| Highlands Ranch Wsd | 103,444 | 3 ppb |
| Parker Wsd | 75,949 | 2.6 ppb |
| Meridian Md | 23,415 | 0 (not detected) |
| Stonegate Md | 15,295 | 2 ppb |
| Roxborough Wsd | 13,765 | 5 ppb |
| Pinery Wwd | 12,901 | 0 (not detected) |
| Castle Pines North Md | 12,800 | 0 (not detected) |
| Sterling Ranch Cab | 11,501 | 0 (not detected) |
| Cottonwood Wsd | 10,867 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Sedalia, 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 Thunderbird 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. The action level is dropping - the 10 ppb rule from 2027.