WATER CLEANUP IS ORDERED NITRATE LEVELS RULED TOO HIGH AT SEWAGE TREATMENT PLANT.

Byline: Jim Skeen Staff Writer

PALMDALE - Palmdale's sewage treatment plant operators have been ordered to clean a contaminated groundwater plume as soon as possible and to look at longer-term options that won't use more precious aquifer supplies.

The Lahontan Regional Water Quality Control Board directed Los Angeles County Sanitation District 20 to begin ``in the shortest possible time'' treating groundwater tainted by nitrates to the state drinking water standard of less than 10 milligrams per liter.

The plume, in underground water east of Air Force Plant 42, has nitrate concentrations as high as 14 milligrams per liter. No drinking-water wells draw from that area, officials said.

The state board, which met in Lancaster on Wednesday night, also directed the sanitation district to report back within a year on cleanup options that do not rely on treating the groundwater by pumping it for use on fodder crops, which is what the short-term cleanup relies on.

The board also stated it wants the water quality to return to what it was before the contamination, under 2 milligrams per liter.

``The district is very sensitive to the overdraft issue,'' said Raymond Tremblay, supervising engineer of the sanitation district. ``We are only suggesting a limited amount of pumping to treat the groundwater.''

Sanitation officials will look for ways to replace existing uses of groundwater to ease concerns about pumping out water for treatment.

The sanitation district is favoring an option that involves the installation of five wells to pump out water with high nitrate concentrations. The water would be placed in storage ponds along 40th Street East until it is needed to water crops.

That option would remove 119 tons of nitrates and would cost about $10.6 million in construction costs and over 20 years of operations and maintenance.

Lahontan staff is concerned about the amount of groundwater that would be pumped out for that option, an estimated 24,600 acre-feet over 20 years. However, while Lahontan can set the cleanup standards, it can not dictate a cleanup method.

Lahontan board member Keith Dyas said he would have liked to see the water pumped, treated through a process called reverse osmosis, and returned to the ground. However, that process is costly: One option considered by the district that included reverse osmosis was estimated at $158 million.

While not viewing it as an ideal method, the board did not object to the district's preferred option, Dyas said.

``The overdraft is a major concern in the Antelope Valley, but I don't want to get into the business of telling people what they can pump under their own ground,'' Dyas said.

Reverse osmosis was a method also suggested by former Lahontan board member Eugene Nebeker, who spoke at the Wednesday meeting. Nebeker, who farms alfalfa using effluent from the Lancaster sanitation district, said the overuse of effluent water on fodder crops has given the practice a bad name.

Nebeker said the district's look at the economics of the cleanup options was flawed, in part because it did not consider damage to the region's groundwater supply if the nitrate plume spreads to the Litte Rock Creek, a prime water recharge area.

``The cleanup should be quicker, the cleanup should be better,'' Nebeker said.

In November 2003, the Lahontan board issued a cleanup and abatement order to the sanitation district and to Los Angeles World Airports, which owns the 2,680 acres the district uses for wastewater disposal east of Air Force Plant 42.

Nitrates are a nutrient for plants but can cause a condition known as ``blue baby'' syndrome among infants. Nitrates have leached into the underground water table from Sanitation District 20's practice of spreading treated sewage effluent on barren land to soak into the ground.

``Some things we know have to stop,'' said Lahontan board member Henry Hearns, who is also Lancaster's vice mayor. ``The land spreading (spreading effluent on open ground) has to stop.''

Nitrates in well water pulled from near the spreading grounds since 1990 have periodically tested above the state cleanup level of 10 milligrams per liter, and computer projections show that if things don't change by 2025, the level could reach 24 milligrams per liter.

Jim Skeen, [phone]

james.skeen(at)dailynews.com