Contaminant guide

Haloacetic acids (HAA5)

HAA5 are another group of disinfection byproducts formed when chlorine reacts with organic matter.

Health context

Long-term exposure above the MCL is linked to increased cancer risk.

EPA standard notes

EPA MCL for HAA5 is 0.060 mg/L (60 µg/L) as a locational running annual average.

Standards and rules change—confirm on epa.gov/sdwa.

What you can do

Review CCR disinfectant byproduct sections.
Certified carbon filtration may help at the tap for some HAAs.

FAQ

Is a filter required?

Not automatically. Many systems meet standards without point-of-use filters. Filters can be useful for taste, specific contaminants, or home plumbing issues—match certifications to the problem.

Where should I verify numbers?

Your utility’s Consumer Confidence Report, public notices, TCEQ resources, and EPA ECHO/SDWIS records.