Water Factory 21 is a water reuse project of the Orange County Water District. Municipal wastewater is purified then injected into the water table. The process is called the Orange County Groundwater Replenishment System.
- Water Factory 21
- Groundwater Replenishment System website
- "Creating Water Quality Confidence" on the website of the WateReuse Foundation
- "From Sewage, Added Water for Drinking" article by Randal C. Archibold in The New York Times November 27, 2007
- "A Tall, Cool Drink of ... Sewage?" article by Elizabeth Royte in The New York Times Magazine August 8, 2008