Outline for Sewage Overhaul Calls for Three Major Plants
The engineers designing the upgrading of San Diego’s massive sewage treatment system recommended a $2.6- to $2.8-billion construction project Friday that would add treatment plants near the Golden Triangle and in the Tijuana River Valley, along with four satellite water reclamation plants.
The plan is a basic outline of the controversial project done for the City Council, which will choose late this year from four detailed alternatives offered by the engineers, after extensive review by the public and a host of other regional governmental agencies.
The outline calls for three major sewage treatment plants: a North City plant on the Eastgate Mall just east of Interstate 805 in University City, an expanded Point Loma treatment plant and a South Bay plant off Dairy Mart Road capable of handling south San Diego effluent and the millions of gallons of Mexican sewage that spills down onto American soil each day. A total of six other options in all three areas are offered if those locations are found unacceptable.
The treatment plants would be sized to handle the 341 million gallons of sewage generated in those areas by the estimated 2.9 million people who will live within the boundaries of the Metropolitan Sewerage System, which stretches from the Mexican border to Del Mar and east to Santee, by the year 2050.
“What we’ve really narrowed down to is a design option that allows us to treat sewage where sewage is generated,” said Roger Frauenfelder, the deputy city manager who oversees the city’s Water Utilities Department.
City’s Twin Goal
The city’s twin goal of cleansing and reusing as much as 120 million gallons of sewage daily would be accomplished by construction of six water reclamation plants and a network of 2,200 miles of pipeline that would carry the water to golf courses, parks and other sites around the county where it would be used for irrigation.
The plants would be in North City, where the treatment plant would double as a water reclamation facility, cleansing all sewage received for reuse; Poway, where construction is already under way; Santee, where planning is already under way; Mission Valley; the Otay River Valley, and the lower Tijuana River Valley, where the plant would sit side-by-side with the sewage treatment facility. That facility would include an ocean outfall for dumping of treated sewage and excess reclaimed water in winter, when it is not needed.
Release of the outline represents a planning milestone for James M. Montgomery Consulting Engineers, the firm that holds a three-year, $9.1-million contract to design the sewage system upgrading mandated by the federal Clean Water Act. The Environmental Protection Agency sued the city a year ago for failing to meet the legislation’s July 1, 1988, deadline for construction of a new treatment system.
But the plan’s debut comes at a time of increasing skepticism among council members that the upgrading to “secondary treatment,” which would remove 85% to 90% of suspended solids from the effluent, is environmentally necessary, especially at a cost that planners said Friday could exceed $2 billion. The remainder of the project’s cost is for water reclamation technology and other facilities.
Buoyed by the testimony of Scripps Institution of Oceanography scientists, who claim that the city’s existing sewage flow is not harming the ocean environment where it is dumped off Point Loma, Councilman Bruce Henderson, the project’s chief critic, has been able to attract increasing support among colleagues reticent to raise residential sewer fees to pay to upgrade sewage treatment.
The council is scheduled to vote Monday on a 47% increase in sewer rates that would raise monthly residential bills from $13.52 to $19.87, effective last July 1. The Water Utilities Department also wants another increase, to $29.22, effective July 1, 1990.
Some council members, however, are considering a smaller increase that would eliminate funds not needed to build water reclamation facilities.
Henderson’s opponents note that the city must comply with the Clean Water Act unless it can win an exemption from Congress, which is considered highly unlikely. Cutting funds for secondary treatment also might jeopardize negotiations toward settling the EPA lawsuit. City lawyers are attempting to show U. S. Justice Department attorneys that the council is making a good-faith effort to build the treatment system.
Because of the legal negotiations, which primarily involve a timetable for construction of the treatment system, planners refused to predict Friday when the new system will open. But the plan they released calls for a two-stage construction timetable that would require most of the spending to occur before 2010.
Under those estimates, $2.25 billion to $2.49 billion would be spent to build treatment plants capable of handling sewage flows of 248 million gallons each day through 2010, depending on the option chosen by the council. Later, another $343 million to $374 million would be required to expand the facilities for use through 2050, when sewage flows would reach 341 million gallons daily.
The engineers estimated that, by 2050, the North City plant would be receiving 45 million gallons daily; the expanded Pont Loma plant would handle 100 or 150 million gallons daily, depending on the configuration chosen by the council, and the South Bay plant would dispose of 75 or 125 million gallons each day.
Of that total, as much as 120 million gallons would be reclaimed daily for irrigation by 2010.
Tons of thick sludge left over by the treatment process would be composted in the San Pasqual Valley, where it could be used on agricultural land or sold as a soil conditioner, the report recommends.