Work Set to Cut Sewage Spills Fouling Mission Bay

In a step toward improving the quality of Mission Bay waters, the city will begin work this month on a $19.3-million sewer line expected to reduce overflow problems that now taint the bay’s image.

“We think the whole project will greatly reduce the amount of spills into the bay,” Water Utilities Department spokesman Kurt Kidman said. “The only way to wipe out that reputation (of sewage problems) is to have a good long string of days when none of the bay is closed down. That’s what we’re shooting for with this project.”

On rainy days, sewage seeps into Mission Bay when effluent rises to street surfaces and runs along storm drains that lead to the bay, said Afshin Oskoui, an engineer with the city’s Water Utilities Department.

The bay’s water quality problems, particularly in the northeast corner, have led to 1,500 days of partial closures between 1980 and 1988, according to a report released in December.

The additional four-mile stretch of sewer line would reduce the number of overflows by picking up the slack for the East Mission Bay sewer line, which now operates at capacity, Oskoui said. The east line runs along Garnet Avenue and, on heavy rainfall days, it transports an estimated 45 million gallons of sewage to the Point Loma treatment plant.

The new line, scheduled for completion in December, 1993, will run south from Santa Fe Street to Morena Boulevard just short of Vega Street in Bay Park. It then veers west to Pacific Highway to just north of the San Diego River.

Installing the additional pipeline is expected to spark traffic delays in nearby neighborhoods throughout this year and the next. The city’s Water Utilities Department has sent letters to area residents apologizing for the predicted inconveniences.

In a separate project, city park planners also are looking at ways to improve the bay’s water quality as they embark on an ambitious effort to update Mission Bay’s master plan.

Suggestions so far have centered on a watershed management program for Rose Creek to catch urban runoff before it hits the bay. Expanding marshland at the foot of Rose Creek east into De Anza property has also been viewed as away to improve the bay’s water quality by acting as an additional filter.