Williams, CA Water Safety: 82/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Within Williams, safety indicators for tap water remain above the CA median — documented violations are infrequent and the city's compliance record sits in the upper tier.
How Williams Compares
Data: EPA SDWIS Last verified: 2026-06-03
Williams Water: The Quick Version
- Homes built before 1986: 44% — older plumbing may contain lead solder.
- Estimated remediation: $1,800 per household.
- CDC health risk index: 12.53 — above typical levels.
Water Systems Serving Williams
Water supply in Williams, CA follows a divided structure: 3 utilities account for the largest share of residential service out of 3 total systems, each managing its own distribution network and EPA reporting. Because these systems operate independently, rate decisions and compliance outcomes are determined separately.
Overview
We track water quality and home safety data for 1 ZIP code in Williams, California (population ~6,489), covering 3 community water systems serving approximately 12,040 people region-wide.
No EPA violations recorded across any ZIP codes in Williams — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Williams: B (82/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Williams water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Williams
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 95987 | B | City of Williams | 5,538 |
All ZIP Codes in Williams
- 95987 [B]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
CDC Health Data for Williams
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
How Old Is Williams's Housing Stock?
With 44% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Williams's residential inventory spans multiple construction eras, with the median build year of 1997 landing in a zone where pre- and post-1986 homes are both well represented. That split matters because homes built before 1986 may contain lead-soldered copper joints — a plumbing practice banned that year — while those built before 1970 face the additional possibility of lead pipes in the service line. Whether a specific household sits on the older or newer end of this distribution is the primary variable shaping its individual exposure risk.
Most homes in Williams were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Williams: Remediation Cost in Perspective
Remediation costs in Williams are small relative to typical property values — the cost-to-value ratio here is favorable.
Remediation costs in Williams are relatively low compared to home values. The $1,200–$2,500 estimated range is a small fraction of median property value. Home values are 50% below the California average.
Protecting Children from Lead in Williams
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Households with kids in the home — for whom CDC guidance places particular weight on minimizing exposure — face a specific local picture in Williams. 44% of homes here come from the pre-rule era, and aggregate utility samples either approach or cross 0.015 mg/L. A baseline draw-test kit and certified lead-removal filtration are available via retailer networks for households confirming conditions at a specific tap.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Williams
A moderate NFIP record for Williams — 16 insurance claims paired with 100% of ZIP codes in FEMA flood zones — points to a flood history where water-quality pathways have likely been periodically relevant.
Williams has a moderate flood history with 16 FEMA claims averaging $27,401 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,800</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Williams, CA