Plan Would Mean Steady Flow for Santa Margarita : Agency Proposal to Pour Highly Treated Waste Water Into River Is Getting a Generally Good Reception

In this land of drought and sun, most rivers have a hard time behaving like rivers.

So it is with the Santa Margarita, which cuts a serpentine path across North County. Though it roars wide and frothy when winter rains hit, the river is a mere trickle during dry months.

All that could change, however, in the next few years. A Riverside County water agency has plans that would make the Santa Margarita run with water year-round by tapping an unlikely source: sewage.

The Eastern Municipal Water District, which serves about 300,000 people in the sprawling Inland Empire, is investigating the concept of dumping excess sewage from the Rancho California area into the Santa Margarita--after it has been highly treated and cleansed of impurities.

A Ready Outlet for Sewage

In effect, the agency would be taking over where Mother Nature left off, providing a daily source of water for the often-parched river. In return, the water district will have a ready outlet for the burgeoning flow of sewage it handles in Rancho California, a booming area that is expected to grow eightfold in the coming decades from its current population of 25,000.

So far, the idea--known as live-stream discharge--has received a cordial reception from regulatory agencies and some downstream users, among them the Camp Pendleton Marine Corps base. Even environmentalists who don’t shy away from a fight have taken a wait-and-see approach to the concept.

Under the plan, sewage from Rancho California would be treated at a plant near Murietta Creek, which flows into the Santa Margarita. Aside from the normal processing to remove solids and pathogens, the waste water would receive tertiary treatment, which uses chlorine to purify the effluent.

“It’s an extremely high level of treatment,” said Bill Plummer, assistant chief engineer at Eastern Municipal. “Basically, it would allow you to swim in it, spray it on edible plants, do everything but drink it.”

During summer months, most of the treated effluent would be reclaimed and used to quench the thirst of everything from golf courses and vineyards to sod farms and cemeteries. But during winter months, when the demand for reclaimed water drops dramatically, the plant would flush treated effluent into the creek and, hence, the Santa Margarita River.

Although the yield to the river would drop in dry months, Plummer said a steady flow would always be maintained to ensure that environmental habitats created by the new flow are not left high and dry.

This would not, however, be a raging river. In the summer, Plummer predicts, the additional water would cause the Santa Margarita to seem much like a babbling mountain stream, perhaps only six inches deep. In the winter, the effluent would likely represent a small fraction of the river’s total water volume, he said.

A Higher Water Flow

“Some people think we’d be creating a lush garden with waterfalls,” Plummer said. “It won’t do that, but it will maintain a little higher water flow, which enhances the environment out there.”

Currently, the agency gets rid of its treated effluent by pumping it into about 50 acres of holding ponds, where it percolates down into the ground water table. The Rancho California plant, one of half a dozen operated by the agency, processes about 2.3 million gallons of sewage a day. That total is expected to soar to 30 million gallons daily during the next 50 years.

Live-stream discharge is already in use on scores of rivers throughout the country, most notably the Mississippi. In Southern California, sewage agencies have steered more toward dumping effluent in the ocean, but several inland agencies already dump treated waste water into the Santa Ana River.

Hopes for 1992

Eastern Municipal hopes to have its plans for the Santa Margarita approved and in place by 1992, but will turn elsewhere if necessary.

Plummer said the agency is also eyeing Lake Elsinore in Riverside County and the San Luis Rey River in North County as potential repositories for the effluent. To reach either site, however, the agency would have to construct a pipeline along existing roadway.

With such costs in mind, agency officials favor the Santa Margarita because virtually no piping would be necessary, other than a short stub from the Rancho California sewage plant to the creek that feeds the river.

While the proposal still faces numerous regulatory hurdles, including hearings before the state and regional water quality control boards and the federal Environmental Protection Agency, neighbors along the Santa Margarita seem to be embracing the idea.

At Camp Pendleton, in particular, officials suggest that the infusion of treated effluent into the river could help the water quality situation on base, where more than 35,000 people depend on underground aquifers recharged by the Santa Margarita.

In particular, the Marines are excited about the concept because the treated effluent is expected to be of far better quality than the water that currently courses down the river.

Runoff From Dairies, Farms

During dry months, the river flows with a troubling brew that consists almost entirely of pollution-laden runoff from dairies, farms and horse ranches. The introduction of effluent from Rancho California would help dilute the existing flows, upgrading the water that percolates into Camp Pendleton’s underground basins, authorities predict.

“In general, I have a kind of warm and fuzzy feeling about it,” said Larry Carlson, acting natural resources director for the base. “The jury is still out, but I think I’m more positive about it than negative. There’s some down sides, but there are some real positive things that live-stream discharge will do for us.”

While base officials appear bullish on the project, Fallbrook water officials are eager to ensure that the treated waste water is diverted south of their community if they elect to build a dam on the Santa Margarita.

So far, the dam has been an on-again, off-again project, and some officials outside Fallbrook remain skeptical that it will ever be built. If the structure does become a reality, however, Plummer said that it might dash live-stream discharge in the Santa Margarita because of the high cost of laying a pipe through the rugged region to pump the effluent around a dam.

Environmentalists, meanwhile, are biding their time while a review of the potential ecological impacts is conducted.

Concern for Bird Habitats

Evelyn Ashton, a leader of Friends of the Santa Margarita River, said the proposal has yet to generate much of a hubbub within environmental circles. She has heard some concern, however, about the potential impact on bird habitats from the increased flow of water in the river.

In particular, the nesting grounds of the light-footed clapper rail, a bird on the U.S. endangered species list, could be affected, she said. In North County, the birds nest in Camp Pendleton on a salt marsh estuary near the mouth of the Santa Margarita.

Other environmentalists have expressed concern that the additional water could alter the types of plants or animals that live along the stream banks.

Plummer, however, said his agency does not believe the volume will be great enough to cause such a metamorphosis. Moreover, he said the water would be clean enough that it would not prove a health hazard for animals that drink from the stream.

Will Remove Nutrients

Plummer noted that the treatment process will help to remove nutrients from the waste water that are key building blocks for plant growth. Otherwise, the effluent could stimulate an eruption of plant life and algae along the river, creating odors and providing a prime breeding ground for mosquitoes.

Michael McCann, a senior engineer with the Regional Water Quality Control Board, suggested that the project could be a boon for the lands straddling the Santa Margarita.

“It appears to be a real good project, something that could be helpful for that area,” McCann said. “Usually, people don’t think of waste water being discharged into a stream as a good situation . . . but, if this flies, it could mean real benefits downstream.”