Water, Water

Los Angeles has two major water problems. The first is too little water. The second is too much water.

California’s imminent water shortage by now is well known. Because the state is facing its fourth consecutive year of drought, residents are bracing for some strict water-saving measures--bans on using water to hose down driveways or sprinkle lawns and gardens, moratoriums on new connections and household rationing.

Then how can Los Angeles have too much water? Each year the city and county produce billions of gallons of sewage waste-water, most of which is partially treated then dumped into the Pacific. This effluent is a major source of coastal water pollution. Equally important, it is lost forever as a valuable source of recycled water.

The real problem, then, is finding a way to resolve this hydrologic paradox. Can the billions of gallons of sewage dumped into Southern California coastal waters be redirected to profitable use? And if this water is so polluted, is it safe to do so?

To answer these questions, some background is needed on water use in the region and methods of waste-water reclamation.

The serious water shortages facing Southern California should come as no surprise. After all, America’s second-largest city sits in the middle of what is essentially a desert. What is surprising is that the problem has been postponed for so long.

For many years Southern Californians have been spoiled by ample water deliveries, despite rapid population growth and sparse local supplies. In 1952 the Metropolitan Water District issued the Laguna Declaration, which promised to supply Southern California with sufficient water to spur postwar economic growth. And it did so with a vengeance--water from the Colorado River, the Mono Lake basin, the High Sierra and the Owens Valley bathed Los Angeles despite steady population growth over the past half-century.

But now, many of Southern California’s traditional outside water sources are drying up. Because of a court decision a quarter-century ago, California’s share of the Colorado River is being reduced. Other litigation has cut water supplies from Mono Lake and the Owens Valley. Combined with four years of below-average precipitation, the region now faces a severe shortage.

More important, the steady stream of low-priced water has given Southern Californians little incentive to use it efficiently. Americans in general treat water as a virtually unlimited resource, using almost 50% more water per capita than the nearest runner-up nation, and almost five times as much as some industrialized countries. But Southern California, because the area is hotter and drier than other regions, uses about twice as much water per person than is the case in New York or other Eastern states. And California is almost entirely dependent on irrigation to grow more than 200 crops.

Part of the solution to this problem lies in more efficient use of water. While conservation--such as installing toilets that use only 1.5 gallons per flush, as Los Angeles has mandated, and water-saving showerheads and faucets--can and should make a big difference, an equally valid aspect is why water rationing is imminent when billions of gallons of water are being dumped into the Pacific each year. Sixteen sewage-treatment plants from Santa Barbara to San Diego dump 1.3 billion gallons of waste-water every day into Southern California coastal waters.

Why can’t this water be reused to help meet the region’s fresh-water needs? One reason is that this sewage--much of which receives only advanced primary treatment--carries with it massive amounts of pollution.

Many of these pollutants can be removed with better treatment. While not clean enough to drink or use for other human-contact uses, adequately treated sewage water can be reused as irrigation water for crops, forests and parks and to recharge ground-water deposits. In some cases, pollutants that interfere with water reuse--especially metals and other toxics--come from industries that discharge their wastes into public sewage-treatment plants. These industries are legally required to “pretreat” their wastes before they reach sewage plants; better pre-treatment and enforcement of existing standards would allow cleaner, reusable sewage effluent.

Some of the chemicals--such as nitrogen and phosphorus--seen as “contaminants” in sewage effluent are actually beneficial nutrients in irrigation water. Sewage reuse can improve agriculture, because nutrients are released slowly, rather than in a single large dose, as is the case with chemical fertilizers.

Waste-water reuse is not a new idea. There are more than 1,000 waste-water reuse projects in the United States in which water is reused for irrigation, industrial cooling and processing and ground-water recharge. In the Los Angeles area, about 30% of the sewage water produced by the county--160 million gallons per day out of 530 million gallons--is treated in levels clean enough for reuse--irrigation of parks, aquifer recharge and industrial uses. These are noteworthy efforts. But less than half of this highly treated water (70 million out of 160 million gallons per day) is reused, with the remaining 90 million gallons discharged daily into the ocean.

The city of Los Angeles and other Southern California communities are even further behind in water-reuse programs, but there is some progress. San Diego, for example, is building a 1-million-gallon-per-day reclamation facility, scheduled to open in 1991, to sell reclaimed water to area growers, local industries and Caltrans. Los Angeles has reclaimed water available in Griffith Park and the Sepulveda Basin.

Nationwide only about a fifth of 1% of water use in the United States is met by reclaimed water. By comparison, reclaimed water met 4% of Israel’s total water needs in 1980, and is expected to reach 16% by the year 2000. Surely we can do much better, both in the Los Angeles region and in the nation as a whole.

The Metropolitan Water District, which supplies 500 billion gallons each year to the area’s 13 million residents, is predicting a 12% shortfall this year--a deficit of about 60 billion gallons, or 164 million gallons per day. The 90 million gallons of reusable water that Los Angeles County alone dumps into the Pacific each day could meet more than half the area’s impending water shortage.

Distribution cost and the lack of adequate conveyance systems are the primary reasons why less than half of this waste water is reused. It is ironic that water transported hundreds of miles across the state, from Mono Lake and the Colorado River, has an economic advantage over water reclaimed in the county because of conveyance costs.

Recycled water should probably not be used for drinking water or other home consumption. But only a small fraction of total water use is in the home--in California, for example, nine out of every 10 gallons of fresh water are used for crop irrigation. Potable-quality water currently going to crop irrigation could be sent to Los Angeles for urban use, in return for nutrient-rich reclaimed sewage water for crop irrigation. Much work needs to be done to determine the best ways to increase waste-water reuse in Southern California. What is abundantly clear, however, is that the region will no longer be able to turn to water from other areas to meet current water needs--much less any additional growth. At the same time, Los Angeles and environs can no longer afford to commit the dual sin of polluting Southern California’s valuable coastline with poorly treated sewage while throwing away billions of gallons of a scarce resource.