Recycled Water

Innovative Approach. Reliable Source.

Water is too valuable to be used just once. IRWD meets roughly 25 percent of our service area’s water demands with recycled water. The use of recycled water extends our drinking water supplies, reduces the need for additional potable water facilities, reduces the amount of treated wastewater discharged into the ocean, reduces our reliance on costly imported water supplies, and increases our water supply reliability. In fact, the use of recycled water is a key component of IRWD's conservation and water use efficiency programs as every gallon of recycled water used results in a gallon of drinking water that can be saved for potable uses.

RW-pipeslar Energy & Other Energy Saving Projects

Our Recycled Water Program

IRWD is a national leader in recycled water. Our long history of recycled water achievements began in 1963 when our forward-thinking Board of Directors implemented their vision to integrate water recycling into the overall design of our community. The goal was, and continues to be, to enhance our water supply reliability through a comprehensive recycled water program. As a result, IRWD’s scope of services was expanded to include wastewater collection and treatment services for the purpose of producing recycled water. The district began delivering recycled water to its agricultural customers within four years of its initial commitment. Today, IRWD’s nationally recognized recycled water program encompasses a wide variety of uses such as landscape irrigation, industrial processes, and toilet flushing in commercial buildings.


Recycled water production uses natural biological treatment to duplicate nature’s own cleaning processes. Wastewater from the community is collected and treated to tertiary standards at the Michelson Water Recycling Plant located in Irvine and the Los Alisos Water Recycling Plant located in Lake Forest. Tertiary treatment is a high level of treatment that results in excellent quality recycled water that can be reused in the community for state-approved non-drinking water purposes such as irrigation and toilet flushing.

It takes about 16 to 18 hours to produce recycled water – from the time the wastewater enters the plant until the finished product is disinfected and ready for distribution.Once treated, recycled water is delivered throughout the IRWD service area through our extensive recycled water distribution system. Our dual distribution system, which keeps recycled water completely separate from drinking water, uses internationally recognized purple pipe infrastructure to easily identify recycled water systems. IRWD pioneered the use of purple piping which has become the international symbol for recycled water. All recycled water produced at IRWD facilities meets or exceeds state and federal mandates. Currently, we deliver more than 23.5 million gallons of recycled water per day to more than 4,000 customers.

The Distribution System 

The cornerstone of IRWD’s extensive recycled water program is the development of a dual distribution system – one set of pipes for potable water and another set for recycled water. IRWD’s recycled water distribution system reaches most of our service area and continues to grow with the community. Beneath many streets in our service area lie three pipelines – one for drinking water delivery, one for wastewater collection, and the third – also known as the purple pipe – for distribution of recycled water. In fact, IRWD pioneered the use of purple piping which has become the international symbol for recycled water.  

The Result 

IRWD’s recycled water consistently meets or exceeds the California Department of Public Health’s stringent water quality criteria for water reuse. As a result, IRWD has been a leader in all aspects of recycled water including research and design as well as policies and regulation. The high-quality, polished recycled water that leaves the Michelson Water Recycling Plant in Irvine can be used for almost every purpose except drinking.


Recycled water is used primarily for landscape and agricultural irrigation. Landscape irrigation uses include parks, school grounds, golf courses, freeway landscaping and irrigation of common areas managed by many homeowner associations. In addition, recycled water is used for front and backyard irrigation in eligible residential lots, industrial processes, toilet flushing in some office buildings, and in cooling towers.

Have Questions? Please click to read the Recycled Water FAQ

Recycled Water Contact Information

Alex Harris
Recycled Water Supervisor

Recycled Water Links

California Department of Public Health-Drinking Water Guidelines (Purple Book)  
California Department of Public Health – Recycled Water Regulations & Guidance 

California Department of Water Resources
California Water Resources Control Board

Engineering & Planning Document Library
(Check out the library for current copies of IRWD’s Rules and Regulations,Procedural Guidelines - section 5, Recycled Water Checklist, Sign Specifications)

San Diego Regional Water Quality Control Board
Santa Ana Regional Water Quality Control Board

Orange County Health Care Agency 
WateReuse Association (National)

California WateReuse Association
Orange County Chapter-California WateReuse Assoc.  

Liquid News

Student Art Show Arrives at Irvine Ranch Water District The 2014 Metropolitan Water District of Southern California Student Art Exhibit has arrived in the lobby of the Irvine Ranch Water District headquarters office at 15600 Sand Canyon Avenue in Irvine and features the winning art work of Grace Jung,...
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