The Groundwater Replenishment (GWR) System in Orange County, California is an indirect potable
reuse project that will produce 70 million gallons per day (mgd) of water initially with an
ultimate capacity of 130 mgd for groundwater recharge and groundwater basin protection from
seawater intrusion. Sponsored by the Orange County Water District (OCWD) and the Orange
County Sanitation District, the GWR System will be comprised of three major components:
the Advanced Water Purification Facility (AWPF) and pumping stations; a major pipeline
connecting the treatment facilities to existing recharge basins; and, an extension of the existing
seawater intrusion barrier. The AWPF will treat clarified secondary effluent, currently
discharged into the ocean, using microfiltration (MF), reverse osmosis (RO), and advanced
oxidation (ultraviolet light treatment with hydrogen peroxide). The product water will be
pumped to injection wells and recharge basins, where the water will naturally pass through the
ground and blend with Orange County's other sources of groundwater. Besides providing a new,
local source of water, the project will eliminate the need for an additional outfall to the ocean,
and will improve the water quality of the Orange County groundwater basin.
To maintain the seawater intrusion barrier during AWPF construction, OCWD has constructed a
new MF system, installed new RO membranes, and constructed a new ultraviolet (UV) light
treatment system to produce 5 mgd of injection water until AWPF construction is complete,
which is estimated to be in August 2007. This project, known as GWR System Phase 1, consists
of a submersible MF system, the use of polyamide RO membranes, and a low-pressure high-output
(LPHO) UV light with hydrogen peroxide advanced oxidation system.
Once the GWR System Phase 1 construction and startup was complete, a series of water quality
tests was performed on the system. The GWR System Phase 1 successfully completed a 30-day
acceptance test and met the water quality requirements set forth in the California Regional Water
Quality Control Board Producer/User Water Recycling permit. Since June 21, 2004, approximately 5 mgd of GWR System Phase 1 product water has been used to supplement
sources to protect OCWD's groundwater basin against seawater intrusion. Although pilot testing
was performed on the MF and RO membranes prior to constructing the GWR System Phase 1,
this is the first opportunity to operate the system for an extended period of time prior to
implementation of the 70 mgd membrane plant.
This paper presents current MF and RO effluent quality and performance
data as compared to permit requirements, the 30-day acceptance test data and criteria, and past
cellulose acetate RO membrane data from the Water Factory 21 facility.
Includes 8 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 540 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 03/01/2005 |
