There's trouble in Paradise. Or to be more precise, trouble in Paradise Pond in the South Bay.
In that marshy area between Chula Vista and National City, toxic wastes have been found in the soil where a $100-million freeway and the Sweetwater River flood channel are being built.
Soils taken from an area about the size of a city block have been found to contain lead concentrations of up to 24 times the federal Environmental Protection Agency standard, Jim Larson, California Department of Transportation spokesman for the San Diego area, confirmed last week.
Larson stressed, however, that the lead concentrations pose no hazard to workers who are building an eight-lane freeway, Route 54, on both sides of the Sweetwater River.
David Merk, hazardous materials specialist with the county Health Department, also said that there are no wells or other human water sources in the area around the contaminated sector, which is subjected periodically to flooding from the river and salt water inundation from San Diego Bay.
According to a 1980 report by the Council on Environmental Quality, lead is one of the most toxic of substances. The effects of exposure to lead are cumulative, the report says, and chronic exposure can cause fatigue, headaches and ultimately damage to the central nervous system, blood-forming system and the kidneys.
Depending on the results of Caltrans tests now being conducted to determine the extent of the lead contamination, Larson said, Caltrans will develop a program for disposing of an estimated 5,000 to 10,000 cubic yards of contaminated soil according to county and state health codes. The soil will be used as fill in building the freeway or will be disposed of in toxic waste dumps, Caltrans officials said. In the meantime, Larson said, the 300-foot-square site will be fenced off and left undisturbed until later in the construction project.
County officials speculate that the area may have been the site of a private dump that operated from the mid-1920s until 1950. The lead in the soil is believed to be from materials high in lead, such as batteries or paint, deposited there.
Dr. Donald Ramras, county health services director, said Caltrans officials contacted his office about the lead deposits six months ago to determine what steps would be required to meet local toxic waste reporting standards.
Bob Roland, a Caltrans environmental engineer, is conducting test borings in the contaminated area. He said that the soil samples analyzed contain average lead concentrations of 1,500 to 1,700 parts per million. The maximum lead level considered safe by EPA standards is 1,000 parts per million. One soil sample contains a lead concentration of 24,000 parts per million, he said.
Pete Michaels, state Regional Water Quality Control Board hazardous waste officer, said that the lead deposits will pose no danger to wildlife or vegetation because Caltrans plans to remove the contaminated soil, "not leave it lying around where some clapper rail can stumble into it."
Rumor Called Unfounded
A persistent rumor among Caltrans workers held that the lead contamination was caused by the Navy's dumping of paint chips in the swampy area. But Larson said there is no evidence of any recent dumping of toxic materials and no evidence of the source of the toxic waste.
Roland said he first learned that there might be a problem in the Paradise Pond area in June, when he scanned the fine print of a 1973 U.S. Army Corps of Engineers environmental impact statement on the flood-control channel for the Sweetwater River.
One of the 20 test borings made in that check produced a sample that contained higher concentrations of both lead and zinc than EPA standards allow. The other samples showed levels below EPA standards, he said. Recent samples also contained traces of zinc, Roland said, but in concentrations well within EPA's safety standards.
San Diego Caltrans officials admitted that the discovery of hazardous waste in the Sweetwater River area is "a very sensitive matter" because of the recent adverse publicity and high costs of cleaning up a 14.5-acre dump containing toxic materials in the path of the Century Freeway in Lynwood in the Los Angeles area.
Residents near that site charged that Caltrans workers had secretly tried to remove some of the chromium, lead, zinc and mercury wastes there illegally, and that they planned to leave much of the hazardous material on the site without proper protection. The state Transportation Commission has allotted $5 million to remove and dispose of about 100,000 cubic yards of contaminated material from that area, the former Willco dump.
San Diego Site Smaller
Larson said that the San Diego site is very small compared to the Willco one. "Here, the lead is bonded in the soil and poses no problem," he said. "No materials removal would be required except that this material is in a drainage area which will be excavated as part of the freeway construction-flood control channel project."
Larson stressed that Caltrans is taking no shortcuts in dealing with the Paradise Pond toxic waste problem. A certified laboratory has been hired to analyze the soil samples, and proper state and county authorities have been notified and kept informed of the testing, he said.
The $100-million project will not be delayed by the discovery of the toxic material, Larson said. The first phase of construction, now under way, includes an Interstate 5 detour. That road allows for construction of an interchange for I-5 with the new Highway 54, which will run along the boundary of National City and Chula Vista.
Both the freeway and flood control channel will extend east to Interstate 805.
Caltrans officials said the project has been in the planning stages for about 22 years.