Placer County, California: drinking water report. Placer County stretches from the Sacramento suburbs through the Sierra foothills to Lake Tahoe, home to…
Placer County stretches from the Sacramento suburbs through the Sierra foothills to Lake Tahoe, home to about 420,000 residents. Water sources are as varied as the geography – Placer County Water Agency draws from the American River and its tributaries, while communities in the foothills and mountains rely on smaller systems fed by snowmelt-driven creeks and springs. The western part of the county has experienced rapid suburban growth, driven by proximity to Sacramento.
Sierra Nevada source water is among the cleanest in California. Placer County's mountain-fed supplies require minimal treatment compared to Central Valley or Southern California water. UCMR5 data shows low-level PFAS detections in some county systems, primarily in the more developed western areas near Sacramento. According to the California State Water Resources Control Board, two public water systems in the county reported PFAS above state notification levels.
Water quality in the Lake Tahoe basin is monitored under particularly strict standards due to the lake's exceptional clarity and ecological value. Tahoe-area water systems must meet both state drinking water standards and basin-specific environmental protections.
Most Placer County residents enjoy high-quality mountain source water. Western county communities near Sacramento face more typical suburban water quality challenges.
Check your water for data specific to your provider and area. For low-level PFAS concerns, an activated carbon filter is usually sufficient. Our water filter guide covers options. Pull your detailed report, and see our California page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Placer County, CA.
The EPA places Placer County, CA in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
29% of homes in Placer County, CA were built before 1980, and 5% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Placer County, CA averages 7.7 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
Across 58 public water systems serving Placer County, CA with EPA lead testing on record, 2 (3.4%) reported a 90th-percentile lead result above the EPA's 15 ppb action level, and the median is 3 ppb. 18 water systems serving Placer County, CA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Surface Water Treatment Rule | 7 |
| Lead and Copper Rule Revisions | 6 |
| Total Coliform Rule | 3 |
| 1,2,3-Trichloropropane | 1 |
| Total Trihalomethanes (TTHM) | 1 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.