Mar 02, 2001

Proposed Groundwater Replenishment System Project Will Use 50% Less Energy Than Importing Water

Purifying Local Wastewater Requires Less Energy Than Importing Water

The Groundwater Replenishment System, a water purification project proposed by Orange County Water District (OCWD) and Orange County Sanitation District (OCSD), could save 140 million kilowatt hours (kWh) of electricity each year when compared to importing water from Northern California.

If constructed, the energy savings for just Phase I of the project -- which will produce 78,000 acre-feet of new water -- is enough energy to supply 21,300 Orange County homes for one year.

It takes twice as much energy to transport water to Orange County from Northern California than it does to purify local wastewater. Every gallon of water produced by the GWR System is one less gallon of water that must be pumped here from Northern California's Bay-Delta.

The GWR System is a water reclamation project that will initially purify approximately 70 million gallons per day of highly treated wastewater through membrane technology, resulting in near-distilled quality water. Some of the water will be injected underground to form a seawater intrusion barrier along the coast.

The remaining water will be transported to Anaheim and percolated into Orange County's large underground water basin to help lower the mineral content of our groundwater. In addition to providing a new, drought-proof supply of water, the GWR System will also improve the overall quality of Orange County's groundwater basin.

Highly treated wastewater looks like clear mountain stream water, but contains viruses and bacteria and has a higher than desirable mineral content. The GWR System's treatment plant located at OCWD will remove all viruses, bacteria and salts, creating near-distilled quality water.