The retired Mission Bay landfill poses little environmental or health threat, but should still be monitored and treated with caution, according to the results of a four-year-long study released late last year.
The study began in August 2002 when District 6 Councilwoman Donna Frye and San Diego’s Environmental Services Department started a new investigation into the current conditions of the former landfill. The goal of the investigation was to determine the environmental and public health issues surrounding the site.
“We asked what were the approximate limits of the landfill and we asked whether or not it was any kind of a significant health risk, particularly to the public, and the answer came back, ‘no,'” Frye said. “In its current state, it is not currently a health risk. Could that change? Absolutely, and that is what we want to really keep our eye on.”
The site of the Mission Bay landfill covers approximately 120 acres in the area of the southern shore between SeaWorld and Interstate 5 near Fiesta Island. The City of San Diego ran the landfill from 1953 to 1959, burying municipal and industrial wastes. Once the landfill was closed, a cap was placed over the area from material left over from the dredging of Mission Bay.
To help evaluate and advise the city during the investigation, Frye created the Mission Bay Technical Advisory Committee (TAC) as an oversight committee made up of technical experts and community members.
The TAC hired SCS Engineers to complete the assessment report.
While many, including Frye, are happy with the results and recommendations of the report, others question the recommendations for future action.
“I agree with the report, but I disagree with the conclusions,” said David Kennedy, a retired dentist who sat on the TAC.
Despite the finding that there is no significant discharge of contaminants from the Mission Bay landfill into Mission Bay, Kennedy explained that the report discovered there is a gradient of water running from the San Diego River, through the landfill and into Mission Bay.
“This report is based upon ‘dilution is the solution to pollution,'” Kennedy said. “Because if you look at the [monitoring] wells, they come up with some nice hot spots [of contaminants], but when it washes into the bay, it all gets diluted with the tides ” oh, that’s great, not for the fish, but hey, who cares?”
Kennedy believes that the best solution for the site is to dig out the pollutants and move them to more arid land. The new site should be lined with plastic and covered to keep water out, which is not present at the Mission Bay site.
However, others believe this solution would cause more harm than good.
“That is not a good idea,” said David Huntley, a ground-water expert from San Diego State University and member of the TAC. “The major risk would be exposure to the workers.”
He explained that currently the landfill doesn’t pose any substantial risk to users of Mission Bay or users of the park.
“To me, it is very dangerous “¦ to take a situation, which is under control, and then go and expose large numbers of workers, residents that surround the area and things like that, by going in and excavating that landfill. I think it’s ludicrous to propose that,” Huntley said.
Frye agreed.
“I am confident in [the report’s] findings. There were some people who wanted us to get a probe and to puncture the landfill right through the middle of it ” that is not advisable,” she said. “There are others who say, ‘Well, you know there’s trash down there, you need to go in and dig it all up.’ Why would we want to do that? And expose the public to an even greater health risk by digging the whole thing out?”
The report concluded that there was little evidence of persistent pollution from industrial waste and that no landfill gases were detected at the surface. Arsenic was detected at levels above public health standards, which, according to the report, could be the result of naturally elevated levels of arsenic in dirt. That finding raised concerns for Kennedy.
“If there’s high arsenic in that cap, is there high arsenic in other areas of Mission Bay?” he asked. “We should examine that.”
The report also found that portions of the eastern part of the landfill are very thin, which increases the chances of future discharge of landfill gases to the surface. The report proposed dumping soil from other areas over the thin spots of the cap, limiting the scope of future construction projects at the site to curtail excavation, and taking a closer look at turning the site into a park, with grass, trees and a playground.
Huntley assures that if the site does become a park, parents and residents should not be concerned with health risks to the public.
“You would be importing soil that would have no arsenic. [The soil] would have none of the contaminants that the existing landfill cover has, so you would be reducing the exposure to dust and to contact, so there wouldn’t be any risk under those conditions,” he said.
According to Frye, the next step, before any action can be planned, is to send the report to all the regulatory agencies for their input.
It is unknown when agency input will be acquired. For information about the TAC study, visit www.sandiego.gov/citycouncil/cd6/crtk/mblandfill.shtml.