Environmental Monitoring Around San Onofre

For more than 50 years, SCE has operated a comprehensive monitoring program at the San Onofre nuclear plant to ensure the safety and well-being of its workers, the public and the surrounding environment.

We share your appreciation for the beautiful location we live and work in, and take very seriously our role as a steward of the environment. The Pacific Ocean and our surrounding beaches will be protected through rigorous environmental controls and monitoring programs.

We are committed to sharing with the public timely information throughout plant dismantlement and as long as there is nuclear fuel on site.

In summary, the environmental monitoring data collected during 2018 supports a conclusion of no adverse effect on the population or the environment from SONGS. The radiation exposures to people living in the surrounding area from SONGS remain less than 1 (millirem) per year, which is a small fraction of the radiation exposures in the environment from the natural background from terrestrial and cosmic radiation.
- 2018 Annual Radiological Environmental Operating Report

Learn more about our programs:

Comprehensive Environmental Monitoring

SCE currently conducts year-round monitoring of the air, ocean water, ground water, surrounding sediment, soil, vegetation and marine species for radioisotopes. Samples are analyzed onsite as well as off-site by independent labs, as required by the Nuclear Regulatory Commission (NRC), the Environmental Protection Agency, and state programs and reported annually.

Learn more about environmental monitoring

View interactive map of marine sampling

Liquid Batch Releases

Like any industrial site, San Onofre has permits to discharge operational wastewater into the ocean. Non-radiological discharges are cleaned-up to meet stringent criteria set forth by our National Discharge Pollutant Elimination System permit. Radiological releases are governed by SCE’s license with the Nuclear Regulatory Commission.

NRC-regulated liquid batch releases comprise a set volume of water from a specific tank, as opposed to continuous wastewater releases.

These releases are processed and highly diluted before release to the ocean via discharge ports that are more than one mile offshore from San Onofre and meet all regulatory requirements. Reports submitted to the NRC can be found below.

Learn more about the releases and when they will occur

See answers to our FAQs about liquid batch releases

Radiation Monitoring

In addition to the ongoing, 24/7 radiation monitoring within and along the perimeters of the plant, SCE is installing a separate system specifically for the dry cask spent fuel storage system. We are working with independent partners who will assist with the program including the California Department of Public Health Radiologic Health Branch and California State Parks.

Learn more about radiation monitoring

See answers to our FAQs about radiation