Chromium-6 (Hexavalent Chromium) in Drinking Water —...
Valley of the Moon Water District · Boyes Hot Springs, CA · 23,107 people served
Data: EPA SDWIS, ECHO, 2016 Consumer Confidence Report
Chromium-6 (Hexavalent Chromium) Detected in Valley of the Moon Water District
Chromium-6 (Hexavalent Chromium) was detected at 280 ppb in the Valley of the Moon Water District water system serving Boyes Hot Springs, El Verano (CA), exceeding the EPA limit of 100 ppb (total chromium MCL; no federal Cr-6 MCL).
This system serves approximately 23,107 people across 2 ZIP codes.
Data source: 2016 Consumer Confidence Report (CCR) and EPA SDWIS/ECHO.
Detected Levels
| Contaminant | Level Detected | EPA Limit | Status |
|---|---|---|---|
| Hexavalent Chromium | 280 ppb | 10 ppb | Violation |
Health Effects of Chromium-6 (Hexavalent Chromium)
Hexavalent chromium (chromium-6) is classified by the EPA as "likely to be carcinogenic to humans" when ingested. It is associated with increased risk of stomach and gastrointestinal cancers. Made famous by the Erin Brockovich case, chromium-6 was found contaminating drinking water in Hinkley, California. There is currently no federal MCL specific to chromium-6 — only a total chromium MCL of 100 ppb. California previously set a chromium-6 MCL of 10 ppb (withdrawn in 2017), and scientists have recommended levels as low as 0.02 ppb for safety.
Source: ATSDR — Chromium Toxicological Profile; EPA.
EPA Standard
The EPA maximum contaminant level (MCL) for chromium-6 is 100 ppb (total chromium MCL; no federal Cr-6 MCL), governed by the National Primary Drinking Water Regulations (total chromium). Water systems that exceed this limit must notify consumers and take corrective action.
What You Can Do
- Install a reverse osmosis system — the most effective household method for chromium-6 removal
- Strong-base anion exchange resins can also reduce chromium-6 levels
- Standard carbon filters do NOT remove chromium-6
- Have your water tested specifically for hexavalent chromium (Cr-6), not just total chromium
- Check the EWG Tap Water Database for chromium-6 data in your area
- If levels exceed California's former 10 ppb guideline, consider treatment even if below the federal MCL
Recommended Water Filters
The most effective treatment for chromium-6 removal is Reverse Osmosis or Strong-Base Anion Exchange.
| Filter Type | Effectiveness | NSF Standard | Notes |
|---|---|---|---|
| Reverse Osmosis (RO) | 95-99% | NSF 58 | Most effective household treatment for Cr-6 |
| Strong-Base Anion Exchange | 85-95% | NSF 53 | Effective but requires regular media replacement |
| Activated Alumina | 70-90% | NSF 53 | pH-dependent; works best at lower pH |
ZIP Codes Served by This System
Check water quality for your specific ZIP code:
Related Resources
- Valley of the Moon Water District — Full Water System Profile
- Chromium-6 (Hexavalent Chromium) in Drinking Water — Overview
- EPA: Chromium-6 (Hexavalent Chromium)
Detected Levels
| Contaminant | Level Detected | EPA Limit | Status |
|---|---|---|---|
| Hexavalent Chromium | 280 ppb | 10 ppb | Violation |
Recommended Water Filters
The most effective treatment for chromium-6 removal is Reverse Osmosis or Strong-Base Anion Exchange.
| Filter Type | Effectiveness | NSF Standard | Notes |
|---|---|---|---|
| Reverse Osmosis (RO) | 95-99% | NSF 58 | Most effective household treatment for Cr-6 |
| Strong-Base Anion Exchange | 85-95% | NSF 53 | Effective but requires regular media replacement |
| Activated Alumina | 70-90% | NSF 53 | pH-dependent; works best at lower pH |