---
title: "What are the secondary maximum contaminant levels for chloride and color in drinking water under 40 CFR 143.3? Answer in under 100 words."
canonical: https://www.m-i-n-d.ai/minds/water-wastewater/secondary-mcl-chloride-color-40-cfr-143-3
jurisdiction: "US Federal · Safe Drinking Water Act"
last_verified: 2026-08-26
license: CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/
attribution: "Source: MIND (m-i-n-d.ai)"
---

# What are the secondary maximum contaminant levels for chloride and color in drinking water under 40 CFR 143.3? Answer in under 100 words.

Under 40 CFR 143.3, the secondary maximum contaminant level for chloride in drinking water is 250 mg/l, and for color it is 15 color units.

## Sources

- [1] U.S. National Archives, Electronic Code of Federal Regulations — 40 CFR 143.3 — Secondary maximum contaminant levels · https://www.ecfr.gov/current/title-40/section-143.3 · as of 2026-08-26