Public Water System

WOODLAND PARK MUTUAL WATER CO

PWSID CA4000506 · California · 538 people served

Failing

WOODLAND PARK MUTUAL WATER CO is an EPA-regulated public water system in California (PWSID CA4000506). It serves an estimated 538 residents — a rural community of customers — across 1 community across 1 ZIP code.

Over the past five years, WOODLAND PARK MUTUAL WATER CO has recorded 11 EPA health-based violations. The grade of F summarizes this compliance pattern. Specific contaminants, dates, and rule citations are listed in the violation history below.

Service Area

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Centered on the averaged ZIP-code centroid of 1 ZIP served.

Population

538

Cities

ZIPs

Violations

EPA Health-Based Violations

Health-based Maximum Contaminant Level (MCL) violations on file for WOODLAND PARK MUTUAL WATER CO over the past five years of EPA SDWIS reporting.

Nitratechemical

EPA Code 1040 · Maximum Contaminant Level Exceedance

violations

EPA Limit

10 mg/L

Last Reading

12 MG/L

First Reported

Apr 2023

Most Recent

Oct 2025

What this violation means

Nitrate contamination is most acute in agricultural regions where fertilizer and animal waste leach into groundwater. The immediate risk is to formula-fed infants under 6 months — high nitrate levels prevent their blood from carrying oxygen, causing 'blue baby syndrome.' Pregnant women should also avoid high-nitrate water.

Recommended precautions

→Never give untreated high-nitrate water to infants — use bottled water for formula.
→Boiling does NOT remove nitrate. Boiling concentrates it.
→Reverse osmosis, ion exchange, or distillation are the only effective home treatments.
→Private well owners in farming areas should test annually for nitrate.

Read the complete guide to Nitrate

Source: EPA Safe Drinking Water Information System (SDWIS). Health-based violations only. Older violations may have been resolved; check your utility's most recent Consumer Confidence Report for current status.

Cities Served by WOODLAND PARK MUTUAL WATER CO

ARROYO GRANDE

ZIP Codes Served

93420

About this system

EPA records this system as PWSID CA4000506. Data reflects the most recent EPA SDWIS publication as of 2026-05-18. Public Water System Identifiers (PWSIDs) are assigned by the EPA's Safe Drinking Water Act program to track every regulated water utility in the United States. The first two letters typically indicate the state primacy agency. For real-time water quality information, contact WOODLAND PARK MUTUAL WATER CO directly or review their annual Consumer Confidence Report (CCR).