Pollution Reduction Plan Altered to Lessen Danger : Environment: A Redondo Beach utility changes the way it will store a highly toxic chemical. The ammonia solution will be used to cut nitrogen-oxide emissions.

By GEORGE HATCH

June 21, 1992 12 AM PT

TIMES STAFF WRITER

Until last week, it had seemed a classic case of government regulators creating one environmental problem while trying to solve another.

In the interests of cleaner air, the South Coast Air Quality Management District passed a rule in 1989 requiring power plants to sharply reduce the nitrogen-oxide pollutants they send skyward by the year 2000.

But the pollution-control method the agency had in mind involved large-scale storage and use of anhydrous ammonia, a highly toxic chemical that can form a lethal, ground-hugging cloud if it is spilled.

That stirred concern--particularly in Redondo Beach, where in 1990 Southern California Edison began moving forward with a plan to install two 12,000-gallon anhydrous-ammonia tanks at its seaside power station. City leaders resisted, and Edison and the AQMD agreed to study the matter.

Redondo’s resistance paid off. Last week, Edison and AQMD officials said the utility had changed its plan so it can store the ammonia in its aqueous form--an ammonia-and-water solution that is far less dangerous.

Redondo Beach officials welcomed the news. Said City Councilwoman Barbara J. Doerr: “This is wonderful. It makes the situation much safer for Redondo Beach residents.”

The change affects Edison’s power stations in Redondo Beach and El Segundo. Two other electric plants, the Los Angeles Department of Water and Power’s Playa del Rey and Harbor stations, must also install nitrogen-oxide removal systems. But the DWP has long planned on storing the ammonia for them in its aqueous form, city and AQMD officials say.

Prompting the use of ammonia is a move by power producers to meet an AQMD rule requiring an 87% reduction in their nitrogen-oxide emissions by the year 2000. Nitrogen oxides react with hydrocarbon pollution and sunlight to produce low-level ozone, a main ingredient in summertime smog.

Ammonia is a key ingredient in the pollution-control system--called selective catalytic reduction--that power plants plan to use to remove nitrogen oxides from their flues.

Despite the air-quality gains, Redondo Beach officials balked in late 1990 when Edison began preparing to build twin 12,000-gallon anhydrous-ammonia tanks as part of its effort to install such a system. Their concern grew when Edison submitted a state-mandated risk analysis as part of the project in February, 1991.

The study said that a worst-case, uncontrolled spill of 10,200 gallons of anhydrous ammonia at the Redondo plant could send deadly concentrations of ammonia vapors more than a half-mile inland within 15 minutes.

“Anhydrous ammonia is actually a liquefied gas, so if there were a spill it would turn very quickly into a gas. And gases, of course, travel downwind,” said Joel Coster, a hazardous-materials specialist with the Redondo Beach Fire Department. “When you have an ammonia solution, you don’t get as much gas released in the air.”

Last year, AQMD and Edison officials argued that anhydrous ammonia could be stored and handled safely, pointing out that it is used widely in many commercial-refrigeration systems.

But last week, they said that after re-examining the issue, they concluded it would be safer to store the ammonia in its aqueous form, only removing the water from it as it is being injected into the catalytic system.

“It’s a substantially lower risk,” acknowledged Lyle Nelson, an air-quality regulations expert with Edison.

The AQMD, in fact, has decided to require the use of aqueous ammonia on all future selective catalytic systems, said Marty Kay, an energy expert with the agency.

“We did some modeling of the concentrations of ammonia that could occur in a spill and found that they could get bad if there’s an accident,” Kay said. “After doing the modeling, both Edison and (the AQMD) had a change of heart.”