Sierra Bonita Estates, CO
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 14 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. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
Sierra Bonita Estates at a glance
Sierra Bonita Estates serves about 122 people through 48 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws surface water, in Arapahoe County, Colorado. EPA system ID: CO0103710; phone on file: 720-234-3734. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is up 14 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Sierra Bonita Estates is 14 ppb across 3 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 14 ppb over 10 |
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
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. Sierra Bonita Estates's 14 ppb sits at the 100th percentile in Colorado and the 99th nationally (higher means more lead).
Nearby utilities
28 other systems share Arapahoe County; 0 of them have a higher latest lead result than Sierra Bonita Estates. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Aurora City Of | 533,407 | 4.7 ppb |
| East Cherry Creek Valley Wsd | 66,130 | 0 (not detected) |
| Englewood City Of | 59,904 | 5 ppb |
| Southgate Wsd | 55,000 | - |
| Southwest Metropolitan Wsd | 48,648 | - |
| Arapahoe Cnty Wwwa | 31,000 | 0 (not detected) |
| Platte Canyon Wsd | 19,485 | - |
| Willows Wd | 19,000 | - |
| Cherry Creek Village Wd | 9,215 | - |
| Inverness Wsd | 8,140 | 4 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Lakewood, 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 Sierra Bonita Estates 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. This system is in the band the 2027 10 ppb rule changes.