US EPA Establishes Regulatory Limits for PFAS in Drinking Water

On April 10, 2024, the USEPA announced national drinking water standards for PFAS that go into effect in 2027. For more information on the USEPA’s actions regarding PFAS, please visit  

Safety of LADWP’s Drinking Water

The Los Angeles Department of Water and Power (LADWP) assures customers that our drinking water is of the highest quality, and regularly tested. Based on testing to date, LADWP has not detected the six regulated PFAS compounds in the water we serve. LADWP’s ongoing monitoring program and commitment to water quality and safety ensure that our water meets or exceeds all regulatory standards.

What are PFAS?

Poly and Per-fluoroalkyl Substances (PFAS) are a group of thousands of different synthetic chemicals developed in the 1940s for use in a wide range of consumer products and industrial applications. These include carpeting, packaging (including food packaging), non-stick cookware, paints, personal care products, and fire-retardant materials. PFAS are used because of their ability to resist water, oil, stains, and heat. They have been given the nickname “forever chemicals” due to their persistence in the environment and difficulty to break down. 

Of the thousands of PFAS compounds, six have been regulated on the federal and state level: perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and hexafluoropropylene oxide (HFPO) aka GenX.


The Health Effects of PFAS

Individuals can be exposed to PFAS through contaminated food and beverages, consumer products with non-stick, stain-repellant, or water-repellant properties, and in areas where drinking water has been contaminated, often due to industrial or firefighting foam use. To ensure public health, the USEPA has established regulatory limits for PFAS in drinking water:

Chemical MCL (enforceable levels)
PFOA 4.0 ppt
PFOS 4.0 ppt
PFHxS 10 ppt
PFNA 10 ppt
HFPO-DA (GenX) 10 ppt
Mixtures with two or more of PFHxS, PFNA, HFPO-DA (GenX), and PFBS 1.0    (unitless) 
Hazard Index

The California State Water Resources Control Board’s Division of Drinking Water (DDW) has also implemented state advisory levels:

Chemical Notification Level Response Level
PFOA 5.1 ppt 10 ppt
PFOS 6.5 ppt 40 ppt
PFBS 500 ppt 5,000 ppt
PFHxS 3 ppt 20 ppt

Protecting our Customers

In alignment with the finalized PFAS Maximum Contaminant Levels (MCLs) by USEPA, LADWP reaffirms our dedication to providing the safest drinking water. Our proactive approach includes:

Adaptability to New Standards: PFAS has only been detected in one operational well field and at such low levels it is not detectable after blending with treated surface water. In addition, LADWP has increased monitoring at this location to ensure that water served remains at non-detectable levels.

Vigilant Testing: Recognizing the widespread use of PFAS in commercial products, LADWP commits to rigorous testing of our groundwater sources. LADWP has developed a robust Groundwater Monitoring Network System for our groundwater sources to ensure our water quality remains uncompromised. Additionally, LADWP has been monitoring and testing for PFAS in its water sources and distribution system in accordance with federal and state guidance and industry standards. Our testing program reflects our commitment to maintaining the highest standards of water quality and safety for our customers. As we do with other potential contaminants, LADWP will test for and monitor PFAS while working with regulatory agencies to safeguard water quality.

Proactive Measures: While LADWP has not contributed to PFAS pollution, we are dedicated to preventing PFAS from entering our drinking water through source protection and, if necessary, treatment. This includes exploring and pilot testing effective treatment technologies and collaborating with local agencies including the Regional Water Quality Control Board (RWQCB) and the Department of Toxic Substances Control (DTSC).  This will help identify potential PFAS sources and enforce regulations that mandate monitoring and controlling these sources through appropriate treatment measures. 

LADWP also encourages customers to learn about potential PFAS exposures by consulting the resources and links provided at the bottom of this factsheet. 

Addressing PFAS Together

LADWP stands at the forefront of tackling PFAS contamination, not only by adhering to current and forthcoming regulatory standards but by actively contributing to the development of innovative solutions and supporting research into PFAS treatment. Through our efforts, we are committed to protecting public health and ensuring that our water remains safe, clean, and reliable for all our customers.

Additional Resources