Exceeds EPA Limit Nitrate EXCEEDS EPA LIMIT

Nitrate in San Ramon, CA Drinking Water

Nitrate data for San Ramon, California · 86,600 residents · 2 ZIP codes

Across the water systems that serve San Ramon, California, Nitrate has appeared in EPA compliance samples — standard municipal treatment targets this contaminant, though detections in the compliance record indicate it has reached household taps at measurable levels.

10 mg/L (as nitrogen)
EPA MCL
18
EPA Violations
High
Health Risk
Reverse Osmosis or Ion Exchange
Best Filter Method

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-04-05

Nitrate in San Ramon Tap Water

San Ramon, California has 18 EPA violations related to nitrate in drinking water.

This analysis covers 86,600 residents across 2 ZIP codes in San Ramon.

San Ramon's overall water quality grade is D (52/100).

Is Nitrate in San Ramon Water Safe?

Nitrate levels in parts of San Ramon exceed the EPA MCL of 10 mg/L (as nitrogen). The EPA requires water systems to take corrective action when this limit is exceeded.

If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 53 / NSF 58 and testing your water independently.

EPA Violations for Nitrate in San Ramon

Date Violation Type Status ZIP Code
2025-04-01 Nitrate-Nitrite (Known) Known 94582
2025-04-01 Nitrate-Nitrite (Known) Known 94583
2025-01-01 Nitrate-Nitrite (Known) Known 94582
2025-01-01 Nitrate-Nitrite (Known) Known 94583
2024-10-01 Nitrate-Nitrite (Known) Known 94582
2024-10-01 Nitrate-Nitrite (Known) Known 94583
2024-04-01 Nitrate-Nitrite (Known) Known 94582
2024-04-01 Nitrate-Nitrite (Known) Known 94583
2024-01-01 Nitrate-Nitrite (Known) Known 94582
2024-01-01 Nitrate-Nitrite (Known) Known 94583
2023-10-01 Nitrate-Nitrite (Known) Known 94582
2023-10-01 Nitrate-Nitrite (Known) Known 94583
2023-07-01 Nitrate-Nitrite (Known) Known 94582
2023-07-01 Nitrate-Nitrite (Known) Known 94583
2023-04-01 Nitrate-Nitrite (Known) Known 94582
2023-04-01 Nitrate-Nitrite (Known) Known 94583
2023-01-01 Nitrate-Nitrite (Known) Known 94582
2023-01-01 Nitrate-Nitrite (Known) Known 94583

Health Effects of Nitrate

  • Methemoglobinemia ("blue baby syndrome") in infants under 6 months
  • Increased risk of colorectal and bladder cancer (long-term)
  • Thyroid disease from chronic exposure
  • Possible reproductive effects

Health risk severity: High. Governed by the National Primary Drinking Water Regulations.

How Nitrate Gets Into Drinking Water

  • Agricultural fertilizer runoff
  • Animal feedlot operations and manure
  • Septic system leachate
  • Urban stormwater and wastewater discharge

What to Do About Nitrate in San Ramon Water

  1. Reverse osmosis is the most effective method for nitrate removal
  2. Ion exchange systems designed for nitrate can also work
  3. Standard carbon filters do NOT remove nitrate
  4. Boiling water increases nitrate concentration — never boil for nitrate

Look for filters certified under NSF 53 / NSF 58 for nitrate removal.

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