OEHHA performs major risk assessment and hazard evaluation activities relating to chemical contaminants in drinking water. These activities include developing health advisories, Public Health Goals for chemical substances in drinking water, Notification Levels, and providing toxicological assistance for chemical monitoring activities for the drinking water supply. The program also provides education to the public and other governmental agencies on drinking water contamination and drinking water regulatory standards development.

Public Health Goals

Level of a chemical contaminant in drinking water that does not pose a significant risk to health


Legal notices for Public Health Goals and Notification Levels

Notification Levels

Health-based advisory levels for chemicals in drinking water


Reports focusing on water

Human Right to Water

OEHHA’s assessment framework and data tool related to drinking water quality, accessibility, and affordability

Reports, Notices, Documents

May 29, 2020: Announcement of Availability of a Second Public Review Draft Technical Support Document for Proposed Updated Public Health Goal for 1,2-Dibromo-3-Chloropropane in Drinking Water
The draft technical support document presents the scientific information available on the toxicity of 1,2-dibromo-3-chloropropane (DBCP) and the calculation of the updated Public Health Goal (PHG).  The proposed updated PHG of 0.003 parts per billion (ppb) is based on carcinogenicity and is set at a level of risk of one additional cancer case per one million persons exposed over a 70-year lifetime.
Apr 9, 2020: Haloacetic Acids in Drinking Water
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.  
Feb 7, 2020: Announcement of Publication of Public Health Goals and Technical Support Document for Trihalomethanes In Drinking Water
The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency is announcing the publication of Public Health Goals (PHGs) for four trihalomethanes (THMs) found in drinking water as a result of disinfection methods: chloroform, bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform.  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.