Haloacetic Acids in Drinking Water

Adoption of Public Health Goals for Five Haloacetic Acids

On December 30, 2022, the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) has adopted and published Public Health Goals (PHGs) for the five regulated haloacetic acids (HAAs) found in drinking water as a result of disinfection methods: monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), monobromoacetic acid (MBA), and dibromoacetic acid (DBA).  

A PHG is the level of a drinking water contaminant at which adverse health effects are not expected to occur from a lifetime of exposure.  The California Safe Drinking Water Act of 1996^[1] requires OEHHA to develop PHGs based exclusively on public health considerations.^[2] PHGs published by OEHHA are considered by the State Water Resources Control Board in setting drinking water standards (Maximum Contaminant Levels, or MCLs) for California.^[3]

The technical support document presents the scientific information available on the toxicity of the HAAs and the calculation of the PHGs.  The PHGs of 0.2 parts per billion (ppb) for DCA, 0.1 ppb for TCA, and 0.03 ppb for DBA are based on carcinogenicity and are set at a level of risk of one additional cancer case per one million persons exposed over a lifetime.  The PHGs of 53 ppb for MCA and 25 ppb for MBA are based on noncancer health effects. OEHHA also presents health-protective drinking water concentrations for noncancer health effects for DCA, TCA, and DBA.

A companion document contains responses to comments from the two public comment periods and the external scientific peer review conducted pursuant to California Health and Safety Code Section 57004. 

If you have questions regarding this announcement, please contact Hermelinda Jimenez at PHG.Program@oehha.ca.gov or at (916) 324-7572.

Second Public Review Draft

Notice of Availability

On August 19, 2022, the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) announced the availability of a second draft technical support document for proposed public health goals for haloacetic acids in drinking water. The full notice is available for download.

First Public Review Draft

Notice of Availability

On January 31, 2020, the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) announced the availability of a draft technical support document for proposed public health goals for haloacetic acids in drinking water. The full notice is available for download.

Extension of Public Comment Period

The January 31 notice announced a 60-day public comment period, ending on April 1, 2020.  OEHHA has received a request for an extension of the public comment period from the Chlorine Chemistry Division of the American Chemistry Council.  OEHHA hereby extends the submission period for public comments relating to the haloacetic acids until May 1, 2020.

Public Workshop

Postponement of Public Workshop

Due to the ongoing challenges posed by COVID-19, OEHHA is rescheduling the public workshop originally scheduled for March 26, 2020. With the health and safety of our stakeholders and staff in mind, OEHHA plans to reschedule the workshop for late April, with an entirely web-based format.  When a new date for the workshop is determined, OEHHA will provide notice on its website and via listserv.

New Public Workshop Date

The public workshop for the proposed Public Health Goals (PHGs) for haloacetic acids in drinking water has been rescheduled to Tuesday, April 28, 2020, from 1:00 to 3:00 pm Pacific time, or until business in concluded, whichever occurs first.  Due to the COVID-19 emergency, the workshop will be held in an entirely virtual format.  Register for the workshop as it is public and free to attend (view system requirements).  The full Public Workshop notice is available for download.