San Diego Pushes Ambitious System to Reclaim Water

Here’s a quiz: By the year 2010, where does San Diego County plan to locate an extra 180 million gallons of critically needed water every day?

A. In Northern California reservoirs.

B. In the Colorado River.

C. In the toilets, washing machines, dishwashers and sinks of county homes and businesses.

If you picked C, swim to the head of the class.

A thirsty San Diego’s share of Northern California reservoirs and the Colorado River will remain the same during the next 20 years as the population continues to grow. So water districts throughout San Diego County are poised for an unprecedented drive to build one of the nation’s most ambitious water-reclamation systems to save much of the waste water that now pours into the ocean.

Many Involved

Backed by an unusual spectrum of interest groups ranging from environmentalists to the building industry, local officials are planning reclamation projects that in 20 years will convert sewage into 13% of the county water supply.

“It’s implicit that we’re not going to get more water,” said John Foley, chairman of the Regional Water Quality Control Board. “We’ve got to look at conservation and reuse, or we’ve got to look at one hell of a change in our life styles.”

The Metropolitan Sewerage System, which includes the city of San Diego, will generate about 70% of the county’s reclaimed water. The sewerage system, which plans to reclaim as much as 120 million gallons each day, serves 1.5 million users below North County and utilizes the Point Loma sewage-treatment plant.

A key ordinance requiring the use of reclaimed water wherever it is available and “economically feasible” will begin its journey through the San Diego City Council on June 7. The so-called “mandatory-use ordinance” requires developers to begin laying the system of dual piping needed to carry reclaimed water to golf courses, parks, freeway medians and greenbelts, where it will be used without mixing with fresh water.

Technical plans for how and where to build nearly $500 million in water-reclamation projects, which will be part of the city’s planned $2.5-billion secondary sewage treatment system, will come before the council later this summer.

Other districts are planning similar systems, and some are ahead of San Diego. In Carlsbad, the soon-to-be-built Aviara development along Batiquitos Lagoon is already having plumbing installed for reclaimed water.

In Santee, where 1 million gallons of sewage is already reclaimed daily at one of the oldest successful treatment plants in the nation, plans are being made to expand to 4 million gallons per day.

In all, 15 separate projects--six of them components of the gigantic Metropolitan Sewerage System’s clean water program--are in planning or construction stages throughout the county. By 2010, they are expected to reclaim as much as 180 million gallons of waste water daily--100,000 acre-feet each year--for irrigation. That saving is enough to free potable water for the yearly needs of 500,000 people.

Badly under-utilized in San Diego--water districts in the county are reclaiming just 7 million to 8 million gallons of sewage each day, much of it at Camp Pendleton--water reclamation is a long-accepted practice elsewhere, from Orange County to the parched Middle East nations of Saudi Arabia and Israel.

The Los Angeles County Sanitation District’s five treatment plants are today reclaiming 60 million gallons of sewage a day. Orange County’s Irvine Ranch development uses reclaimed water on its golf courses and greenbelts, and the Moulton Niguel system uses reclaimed water for various needs, including decorative fountains.

“We should have been doing this for the last several years,” said San Diego City Councilman Ron Roberts, widely credited as the driving force behind the city’s water-reclamation project. “We’re coming to this very, very late. Many cities in the country are ahead of us.”

Doubters like San Diego City Councilman Bruce Henderson argue that a vigorous statewide conservation program focused on agriculture would be cheaper than local water-reclamation efforts and would save huge supplies of fresh water. Agriculture uses about 80% of the state’s water supply.

Environmentalists, who enthusiastically support water reclamation but see water availability as a natural inhibitor of population growth, are watching carefully to make sure that the new systems do not spur growth by producing an overabundance of water.

“We don’t want to see (reclamation) plants sized beyond a reasonable projection for growth increases,” said John Reaves, chairman of the local Sierra Club’s water-resources subcommittee. “We don’t want to have a capacity which is so much larger than needed that it would encourage growth.”

The Construction Industry Federation, whose legislative committee has formally endorsed water reclamation, is also wary that builders will be forced to bear a disproportionate amount of the cost of the system. Before dual piping is ordered, argues John Seymour, legislative analyst for the federation, builders want specifics on treatment-plant sizes and locations, distribution pipelines, pump stations, cost estimates and financing mechanisms.

“They’d better have those things definitively identified before they start mandating dual piping systems,” Seymour said.

County planners face the daunting logistical and technological task of building the local system nearly from the ground up. Because the county is nearly devoid of underground aquifers for natural water storage, most of the systems will be made up of “on-demand” projects that send water out to users daily.

The metropolitan system alone is tentatively planning six water-reclamation plants, 330 miles of water mains and 2,200 miles of pipeline, which will cost at least $436 million. Storage tanks for 96 million gallons must be built to allow the reclaimed sewage, which flows most heavily during daylight hours, to be gathered before it is dispensed to irrigation systems for nighttime use.

In summer months, the full 120 million gallons will be used each day, but in wet winter months, when demand may plummet to zero, the reclaimed water, which will exceed even secondary-treatment standards, will be poured into the ocean. Average daily use year-round will be about 64 million gallons.

Metropolitan system planners have identified more than 300 top markets for the water, thirsty parcels of ground larger than five acres. The 39 county golf courses now using potable water, and 18 others on the drawing board, are prime candidates for reclaimed water. An 18-hole golf course drinks 1 million gallons of water daily during peak summer heat.

The water will undergo three separate cleaning processes, plus chlorination, to meet state Department of Health Services standards governing human contact with the water, allowing its use on golf courses, ball fields and greenbelts of future condominium complexes. Plans also call for the reclaimed water to be poured into stream beds and pumped into commercial high-rises for use in flushing toilets. A small amount of industrial use is planned.

“You could swim in it or run through the sprinklers,” Harold Bailey, the city’s water-reclamation coordinator told an audience at a recent water-reclamation seminar. “We don’t advocate drinking it.”

The water must be cleansed of much of the salts that could make it useless for irrigation and relieved of some of the nitrates and other nutrients that might cause changes in habitats farther downstream. To prevent even higher salinity, the city of San Diego and other jurisdictions are reserving the right to regulate water softeners, which dump salts into the sewage.

The Regional Water Quality Control Board will be asked to amend several “basin plans” to allow the reclaimed water to be poured into, for example, the San Diego River. Before that can be allowed, Foley said, engineers will have to prove they will control nutrients, mosquitoes and changes that could affect birds and marine animals farther downstream.

Advocates argue that all of the water will be sorely needed. In 1987-88, the county used 580,000 acre-feet of water--319,800 (55%) from the Colorado River, 204,400 (35%) from Oroville Reservoir near Sacramento and 55,800 (10%) from local sources. (An acre-foot is the amount of water needed to cover an acre to a depth of one foot. It is equivalent to 326,000 gallons, and is about enough to serve the needs of an average family for a year.)

As San Diego continues to grow over the next two decades, demand will soar to 800,000 acre-feet, but the Colorado River and State Water Project will deliver no additional water in 2010--just the current 524,200 acre-feet. Local sources will provide less, just 60,000 acre-feet.

That leaves a deficit of more than 200,000 acre-feet yearly. Reclamation is intended to fill about half of the gap, 100,000 acre-feet. Water conservation programs must provide 80,000 acre-feet, and desalination of ocean and brackish water is forecast at 35,800 acre-feet.

Though the total cost of reclaiming water is estimated at $731 an acre-foot--far more than the current $280 per acre-foot price of today’s imported water--metropolitan system planners believe that it will be cheaper than the cost of developing, transporting and treating some new sources of potable water. And with the cost of desalination estimated at $1,450, reclamation is clearly a better buy.

More important, reclamation, like conservation and desalination, gives San Diego a greater degree of independence from imported water. Located literally at the end of the state’s aqueduct system, the county is highly vulnerable to supply cutbacks during a drought.