DWP Calls Reclamation Plan Safe but Sees Traffic Snarls : Drought: Project would deliver up to 50 million gallons per day of treated waste water to industrial and irrigation customers and to spreading basins.

An ambitious plan to stretch city water supplies by using reclaimed water from the Tillman sewage treatment plant in Sepulveda Basin would have no long-term adverse effects, according to a draft environmental report.

But “significant traffic disruption” would occur on three major streets during construction of a 13-mile-long pipeline that is the project’s centerpiece, according to the report by the Los Angeles Department of Water and Power.

The study concerns the East Valley Reclamation Project, which would deliver up to 50 million gallons per day of treated waste water to industrial and irrigation customers and to Pacoima and Sun Valley water spreading basins, where the water would percolate into the ground.

The project would substitute undrinkable but treated waste water for drinking water in such uses as irrigating parks and cooling industrial equipment. By adding to the underground water supply--purified by its passage through the earth--it also would boost the amount of water that could be tapped by city wells in North Hollywood and near Griffith Park.

The DWP now operates one relatively small reclaimed-water project and is developing two other small ones. But the East Valley project would dwarf the others, and would be the city’s first use of reclaimed water to replenish drinking-water supplies. Daily use of all 50 million gallons of reclaimed water in effect would boost Los Angeles’ water supply by about 7% to 8%.

DWP officials said they will take written comments through April 13 on the project, expected to cost $29 million to $38 million. They have also scheduled two public meetings, the first to be held at 7 p.m. today at DWP headquarters at 111 N. Hope St., downtown. The second is scheduled for April 2 at 7 p.m. at Francis Polytechnic High School, 12431 Roscoe Blvd., in Sun Valley.

The project would take advantage of the expansion of the Donald C. Tillman Water Reclamation Plant, after its treatment capacity is doubled to 80 million gallons per day. Tillman’s discharge now makes up most of the Los Angeles River and winds up in the sea.

The East Valley project would divert 50 million gallons from Tillman to a four-foot-diameter pipeline that would run northeast from the Tillman plant. Most of the way, the pipeline would follow an existing DWP power-transmission corridor and the Tujunga Wash.

However, part of the pipeline would be installed under city streets. And during construction, from 1993 to 1995, major traffic snarls could occur on parts of Victory Boulevard, Sherman Way and Glenoaks Boulevard for an unspecified length of time.

From the Tillman plant, the pipeline would go east beneath Victory Boulevard, turn north on Haskell Avenue, then go east under Sherman Way to the Tujunga Wash.

The route continues north along the wash to the DWP’s Rinaldi-Toluca transmission line. From there, a branch of the pipeline would run northwest along the transmission right of way to the Pacoima Spreading Grounds, a series of sand and gravel basins where storm water is diverted to sink into the ground.

The other branch of the pipeline would continue northeast along Tujunga Wash past the Hansen Spreading Grounds, where water would also be diverted. Other water would be pumped to the DWP’s nearby Valley power station for use in cooling.

Beyond the spreading grounds, the route goes to Glenoaks Boulevard and runs northwest along that street. One stub would turn northeast along Osborne Street to the Hansen Dam Recreation Area for possible irrigation and recreational uses. The other would continue along Glenoaks Boulevard to Terra Bella Street, and then to a 2-million-gallon tank on the grounds of Whiteman Airport. The tank would store water for industrial or irrigation customers.

At a public meeting on the proposal last fall, concern was expressed about the project’s promoting development and population growth. The draft environmental report contends that the project won’t “stimulate any new urban growth,” but will help cope with growth that’s already occurring.

The major health concern involves the blending of reclaimed water with ground water that is used for drinking. Here, the DWP is banking on effective treatment at the Tillman plant, dilution of reclaimed water with other supplies and the natural cleansing action of the sand and gravel through which ground water seeps.

A proposed state health regulation requires that reclaimed water make up no more than 20% of potable water drawn from the ground. Water officials say they plan to put enough storm and surface water into the spreading basins to assure that standard is met. They said ground water in the area moves at about 200 to 500 feet per year, and takes at least several years to seep from the spreading grounds to the closest wells.