Photo Gallery: Regional San Echowater

July 28, 2023

After one decade and $1.7 billion across more than 20 projects, the EchoWater project for Regional San is complete, making it the second largest plant of its kind in the U.S.

Regional San spans a 3,200 acre space between Sacramento, California and Elk Grove, California. Of that space, 1,100 acres are process areas with 2,100 acres of buffer land. It treats 135 million gallons per day for a population of 1.6 million people.

Christoph Dobson, Regional San general manager, said the buffer land was purchased years ago with the recognition that the community would expand and eventually encroach on the treatment plant. Keeping that buffer land allows it to ensure noise, odor and dust are not issues for its neighbors.

The decade-long EchoWater project was initiated following communications from the Central Valley Regional Water Quality Control Board in 2010 when it issued new treatment requirements for Regional San’s wastewater discharge permit. Read more about Regional San in the July/August edition of Wastewater Digest and watch the video with Dobson about the facility on our video page.


Christoph Dobson Regional San July August Plant Profile Biological Nurient Removal Tertiary Treatment Final
Plant Profile

Video Profile: Regional San EchoWater

July 28, 2023
Regional San's EchoWater project removes ammonia with biological nutrient removal as the largest California State Revolving Fund project in history at $1.7 billion.
Echo Water Resource Recovery Facility
Plant Profile

Plant Profile: Regional San EchoWater

July 25, 2023
The largest CWSRF project in California completes construction under budget while meeting permitting requirements for ammonia removal.
Photo courtesy Regional San.
The treatment facility's Biological Nutrient Removal project is responsible for removing 99% of ammonia and 89% of nitrogen, addressing concerns about possible impacts downstream.
Wastewater Treatment

Regional San completes $1.7B treatment facility expansion

May 17, 2023
The EchoWater project has helped Regional San’s expanded tertiary treatment facility to remove 99% of ammonia and 89% of nitrogen from wastewater.