The history of  wastewater recycling in Southern California

Recycled water first appeared in Southern California in the 1960’s when Irvine Ranch Water District (IRWD) began providing its water consumers with 2 million gallons a day (mgd) of tertiary treated water for agricultural uses. The 1969 Porter-Cologne Water Quality Control Act became the framework for the standards that led to the regulations for recycled water, commonly referred to as ‘Title 22’ water. In the 1980’s, IRWD and the American Water Works Association (AWWA) worked together to come up with the standardized purple color, known as “Irvine Purple,” to easily identify the recycled water systems that we see today.

Over the next several decades, water reclamation facilities began to appear more and more throughout Southern California. During this time, recycled water use was being expanded for more than agricultural purposes. Orange County Water District began injecting recycled water into their aquifers to combat saltwater intrusion occurring in its groundwater basin. San Diego County began using the recycled wastewater to fill man-made lakes for recreational activities. Communities began seeing recycled water as an economically feasible solution for supplementing local water supplies with the added benefit of treating sewage at the same time.

In 2004, San Diego began making revisions to its Water Reuse Master Plan which led to the development of the Water Reuse Study 2005. This study evaluated reuse options, including advanced water treatment, to see what San Diego could do to become more self-reliant on its water supply. In June 2011, the Pure Water Demonstration Facility went online and began conducting research on the feasibility, safety and cost-effectiveness of using the advanced water purification process to augment our local water supply. In early April 2018, the environmental impact report for the Pure Water San Diego Program was unanimously approved by the city council and given the green light on the first of several phases that will provide one-third of San Diego’s local water supply once the project is completed in 2035.