New Regulations Send Sludge to New Heights

Day in and day out, 660,000 gallons worth is piped 7 1/2 miles underground until it spews into designated ponds on Fiesta Island.

Recycling then begins on San Diego’s liquid waste ooze, better known as sludge. It sits and separates. Solids eventually settle and the liquid is piped back to the Point Loma Waste Water Treatment Plant.

Over a period of months, the sludge is left to dry. It is then bulldozed into hills, where it will be harvested for fertilizer, fuel and lining for future waste water ponds.

The process has occurred for decades, but recently the city has had to extract more solids from the sludge. The result, officials say, are cleaner California waters and a 45,000-ton sludge pile, which stands more than 70 feet high and is visible from nearby Sea World.

Officials say they have not received complaints about the apparent eyesore, but if they do, “we’ll knock down the pile,” said Robert E.L. McCampbell, Point Loma waste water plant supervisor.

McCampbell said that city officials have “never built a ski slope in the past,” but new state sewage treatment guidelines, which took effect in July, have forced workers to find space on the Mission Bay island. The pile’s vertical nature makes it easier for heavy-equipment operators to drive around the mound, he said.

Before the new regulations, the Point Loma plant extracted 60% of suspended particles from about 161.5 million gallons of domestic and industrial waste water that arrived daily at the plant. Today, the plant must remove 75% of the solids, McCampbell said.

“We have been required to increase the efficiency of this facility,” he said, adding that the move has “created quite an increase in our solid disposal rates.”

McCampbell said that in order to meet the state-ordered demands, chemicals are now being used, at a cost of $6,000 a day, to separate the grit, sand and other particles from the waste water more effectively.

McCampbell said the new process should cost the city an extra $600,000 a year.

Meanwhile, the city is taking bids to remove the sludge pile and it should be shipped off the island no later than next spring, McCampbell said.

Until then, McCampbell says that even though the mound is growing, San Diegans can take comfort in the fact that the pile is a sign that county waste water destined for the ocean is that much cleaner.