California · population 52,292
Lead pipes in Diamond Bar, CA
No lead lines reported
Most of Diamond Bar (population 52,292) gets its water from Walnut Valley Water District, which reported 27,655 service lines and no lead, galvanized or unknown lines.
0% of Walnut Valley Water District's service lines are lead or galvanized requiring replacement, lower than the California average (0.1%) and lower than the national average (3.1%).
- Lead 0%
- Galvanized (replace) 0%
- Unknown 0%
- Non-lead 100%
Latest lead test for Walnut Valley Water District (Jan 2022–Dec 2024): not detected at the 90th percentile, against a 15 ppb federal action level. Full test history.
Compliance record: EPA lists no Lead and Copper Rule violations since 2015 for Walnut Valley Water District.
Water systems serving Diamond Bar
| Water system | Lead | Galv. | Unknown | % lead |
|---|---|---|---|---|
| Walnut Valley Water DistrictMain system | 0 | 0 | 0 | 0% |
| City of Chino HillsServes nearby areas | 0 | 0 | 0 | 0% |
Matched from EPA water system service area boundaries and the cities each system reports serving. Edges of the city may be served by a neighboring system; your water bill names your utility.
Check your address in Diamond Bar
The counts above cover the whole water system. To see whether your line is lead, look up your address on Walnut Valley Water District's official inventory. Utilities had to make these public by October 16, 2024.
No map yet? Do the 2-minute scratch and magnet test.
Protect your drinking water
If your line is lead, galvanized or unknown, use a filter certified to NSF/ANSI 53 for lead for drinking, cooking and baby formula, and use only cold water.
Choosing a lead-certified filter · Testing your water · Replacement cost
Nearby cities
- Walnutno lead reported
- Pomonano lead reported
- Breano lead reported
- West Covinano lead reported
- Chino Hillsno lead reported
- Covinano lead reported
- San Dimasno lead reported
- La Puenteno lead reported
Check another water system
Questions
Does Diamond Bar, CA have lead pipes?
Walnut Valley Water District, which serves Diamond Bar, reported no lead, galvanized or unknown service lines.
Who supplies water to Diamond Bar?
EPA's service area maps place most of Diamond Bar in Walnut Valley Water District's service area (PWSID CA1910234). City of Chino Hills also serves parts of the city or nearby areas.
How do I check whether my Diamond Bar home has a lead service line?
Search your address on Walnut Valley Water District's service line inventory map. You can also scratch the pipe where water enters your home: lead is soft, dull gray, scratches to shiny silver and doesn't attract a magnet.
When will lead pipes in Diamond Bar be replaced?
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask Walnut Valley Water District whether your street is scheduled and whether it covers the private side.