AWWA SOURCES55722

The Monterey Peninsula has been experiencing a severe water shortage for at least the last 20 years. Recent rulings by the State of California regarding the revised limited water rights of California American Water Company (Cal-Am) to pump groundwater from the Carmel River Groundwater Basin has made the situation more critical than ever. In September 1994, a water recycling project, known as the Carmel/Pebble Beach Water Reclamation Project, was put on line to irrigate the seven golf courses in Pebble Beach, California. The project was in the development stage for over ten years. During that time, water conservation measures were implemented in the Cal-Am service area, including replacement of toilets with low-flush type units upon change of property ownership. The result to the Water Reclamation Project was that less raw wastewater was ultimately available for processing and recycling on a daily basis than was originally projected. And, the water quality constituents of concern for turf irrigation, namely sodium, chloride, SAR and TDS were all considerably higher than originally anticipated owing to less per capita daily water usage. Water consumption per connection throughout the Cal-Am entire service area, dropped by approximately 40 percent from the middle 1980's to the period from 1994 (project start-up) to 2000. After project operation for the first year, turf deterioration on several greens was observed. The interim solution has been to use potable water for make-up and to "flush" the salt through the root zone of the greens. Gypsum was also added to the recycled water. Owing to local pressures to eliminate use of potable water (an original goal of the initial project) along with the proposed development of another golf course, the need to expand the project became evident. Hence, Phase II of the Reclamation Project has been planned. The Phase II Project consists of rehabilitation and conversion of an abandoned potable water, earthen reservoir for seasonal storage of up to 400 acre-feet of reclaimed water; an algae removal treatment system, should algae growth and other stray contaminants become a problem; and, a salt reduction system consisting of micro-filtration and reverse osmosis. This paper discusses the water quality aspects of the project and the detailed water quality/quantity computer model that was developed to balance total daily irrigation demands with seasonal storage capacity while meeting revised water quality objectives for sodium, SAR and TDS. Numerous operating senarios were evaluated and results of the model are presented along with six years of operating data for irrigation demand. Three types of salt reduction systems were evaluated and results are also presented. Estimated capital and operating costs for the Phase II System are presented.

Product Details

Edition:

Vol. - No.

Published:

01/01/2002

Number of Pages:

34

File Size:

1 file , 610 KB