Public Health Goals (PHGs)

What Is a Public Health Goal?
A PHG is the level of a chemical contaminant in drinking water that does not pose a significant risk to health. PHGs are not regulatory standards. However, state law requires SWRCB to set drinking water standards for chemical contaminants as close to the corresponding PHG as is economically and technologically feasible. In some cases, it may not be feasible for SWRCB to set the drinking water standard for a contaminant at the same level as the PHG. The technology to treat the chemicals may not be available, or the cost of treatment may be very high. SWRCB must consider these factors when developing a drinking water standard.

How Does OEHHA Establish a Public Health Goal?
The process for establishing a PHG for a chemical contaminant in drinking water is very rigorous. OEHHA scientists first compile all relevant scientific information available, which includes studies of the chemical's effects on laboratory animals and studies of humans who have been exposed to the chemical. The scientists use data from these studies to perform a health risk assessment, in which they determine the levels of the contaminant in drinking water that could be associated with various adverse health effects. When calculating a PHG, OEHHA uses all the information it has compiled to identify the level of the chemical in drinking water that would not cause significant adverse health effects in people who drink that water every day for 70 years. OEHHA must also consider any evidence of immediate and severe health effects when setting the PHG.

For cancer‐causing chemicals, OEHHA typically establishes the PHG at the “one‐in‐one million” risk level. At that level, not more than one person in a population of one million people drinking the water daily for 70 years would be expected to develop cancer as a result of exposure to that chemical.

Public Health Goals

Chemical Name Public Health Goal (mg/L) Last Updated
n-Nitrosodimethylamine 0.000003 Dec 22, 2006
Oxamyl 0.026 Apr 24, 2009
Pentachlorophenol 0.0003 Apr 24, 2009
Perchlorate 0.001 Feb 1, 2015
Picloram 0.166 Sep 23, 2016
Polychlorinated Biphenyls 0.00009 Oct 5, 2007
Radium-226 0.05 pCi/L Mar 3, 2006
Radium-228 0.019 pCi/L Mar 3, 2006
Selenium 0.03 Dec 10, 2010
Silvex 0.003 Apr 24, 2014
Simazine 0.004 Sep 20, 2001
Strontium-90 0.35 pCi/L Mar 3, 2006
Styrene 0.0005 Dec 28, 2010
2,3,7,8-Tetrachlorodibenzo-p-dioxin and related compounds (TCDDs) 0.05 picograms/L (pg/L)
1,1,2,2-Tetrachloroethane 0.0001 Sep 26, 2003
Tetrachloroethylene 0.00006 Aug 1, 2001
Thallium 0.0001 Nov 16, 2004
Thiobencarb 0.042 Sep 23, 2016
Toluene 0.15 Feb 16, 1999
Toxaphene 0.00003 Sep 26, 2003