Hexavalent Chromium (Chromium-6) Testing in Orange County: Where Can I Get It – And Why It’s Important 

Hexavalent chromium (chromium-6) is a form of the metallic element chromium. It can occur naturally when chromium-bearing rock and soil erode, and it is also produced by industrial processes such as stainless steel welding, chrome plating and the manufacture of dyes and pigments.

Chromium-6 is odorless and tasteless in water, so you can’t tell by looking or tasting whether it is present. Here is how it is regulated in California, what your utility reports, and how to get your own water tested.

There is no federal drinking water limit specifically for chromium-6. The EPA regulates total chromium at 100 parts per billion (ppb).

California regulates chromium-6 on its own. The State Water Resources Control Board adopted an enforceable limit (MCL) of 10 ppb, which took effect October 1, 2024, with compliance phased in over several years depending on the size of the water system. California’s Public Health Goal for chromium-6, set by the Office of Environmental Health Hazard Assessment (OEHHA), is 0.02 ppb. A Public Health Goal is not an enforceable limit; it is a target used when the state sets and reviews regulations.

This is California’s second chromium-6 limit. The state first adopted a 10 ppb MCL in 2014, but a Sacramento County Superior Court invalidated it in 2017 after a challenge by the California Manufacturers and Technology Association, finding the state had not adequately evaluated economic feasibility. The current limit was adopted in 2024.

Public water systems in Orange County publish an annual Consumer Confidence Report (CCR) that lists detected contaminants, including chromium-6 where it is monitored. The State Water Board also publishes chromium-6 sampling data for California water systems on its chromium-6 page. Your utility’s report reflects water leaving its system; a test of your own tap is how you find out what is reaching your fixtures.

Private wells are not covered by public water system rules, so well owners are responsible for their own testing.

Measuring chromium-6 at the low levels California regulates requires a laboratory analysis by a state-certified lab. Ask the lab for a hexavalent chromium analysis specifically, since a “total chromium” result doesn’t tell you how much is in the hexavalent form.

Culligan’s free in-home water test is a good starting point for understanding your water overall. It measures hardness, chlorine and total dissolved solids (TDS); it does not measure chromium-6. If you want a chromium-6 result, ask us about arranging a certified lab test.

Under-sink reverse osmosis (RO) systems are one of the most common ways to reduce chromium-6 in drinking water at the tap. RO uses a semipermeable membrane to reduce a broad range of dissolved solids. Not every RO system is certified for chromium-6, so check a system’s performance data sheet for what it is certified to reduce, and look for certification to NSF/ANSI Standard 58.

If you have questions about health, talk to your doctor or your county health department.

Water quality can change over time as utilities change sources or as groundwater conditions shift, so periodic testing is worthwhile — especially if you have a private well. If you use an RO system, replacing filters and membranes on schedule keeps it performing as rated. When you have a Culligan RO system, your local Culligan dealer can handle that maintenance for you.