How is drinking water quality regulated?

Federal: The Safe Drinking Water Act established the authority of the US Environmental Protection Agency (EPA) to set regulations for drinking water quality. These standards cover microorganisms, disinfectants, disinfection by-products, inorganic chemicals, and radionuclides. The EPA sets the maximum containment levels (MCL) for regulated contaminants that a utility must meet. Water utilities and the EPA are constantly scanning water for newly identified compounds to determine if additional regulations are necessary. SMWD participates in this effort by analyzing for these unregulated compounds. The last revision made to the Safe Drinking Water Act was a revision to the Total Coliform Rule in 2013 and has indicated that regulations related to PFAS are being worked on currently. 

State: The State of California can also establish and enforce regulations because the EPA has approved California to administer regulations in a concept known as primacy. California’s regulations are established by the State Water Resources Control Board (SWRCB) and must be at least as stringent as those established by the EPA. The SWRCB produced this 2018 report which details both the Federal and State standards. The SWRCB is responsible for setting the MCL “as close as feasible” to the corresponding public health goal (PHG) with primary emphasis on the protection of public health but also considering technological and economic feasibility. Additionally, each primary drinking water standard must be reviewed at least every five years to determine if technology or treatment techniques have changed. The State has produced this website which details the review process.

Show All Answers

1. What is SMWD doing to ensure that your water is safe?
2. What is a Public Health Goal (PHG)?
3. How is drinking water quality regulated?
4. What are trihalomethanes (THM) and haloacetic acids (HAA)?
5. How can I perform my own water testing?
6. Is SMWD water hard or soft?
7. What is the white residue that builds up on silverware, glasses and even my shower door?
8. Why does my tap water sometimes look cloudy?
9. What is the odor that I sometimes smell from my tap or sink faucet?