The Navy went public with the spill last month after discovering that an underground plume of petroleum had unexpectedly migrated north toward the base's border with the La Playa residential community.
The Navy will address concerns and answer questions at the Portuguese SES Hall, 2818 Avenida De Portugal, beginning at 7 p.m.
The submarine base is part of the nation's Strategic Petroleum Reserve network, as well the only west coast Defense Fuel Support Point (DFSP) south of Washington state. Fifty tanks "“ positioned above and below ground "“ store roughly 42 million gallons of fuel on site for the Navy, Army, Marine Corps and Air Force.
In 1999, fuel began dripping from the bottom of one of the aboveground tanks. The following year, sensors alerted officials to the leak and the Navy took that tank offline. Two more leaks were subsequently discovered in 2002 and 2003.
Currently, the amount of escaped fuel is known to be at least 500,000 gallons, while computer estimates suggest as much as 1.5 million gallons. This number cannot be accurately assessed because the fuel is located 50-feet underground.
The plume is six-feet-deep in places and covers a large expanse of property. Because of Point Loma's dry and rocky geology, the leaked fuel initially buried deep under the tanks. It was not until the fuel reached the underground water table, or water saturated ground that it began to spread laterally at a slow rate.
The plume is currently stuck between the fuel depot and the bay as a result of Navy efforts. However, two months ago routine monitoring showed that the fuel was inching toward private property to the north, prompting the Navy to go public on Feb. 7.
District 2 Councilman Kevin Faulconer and Congresswoman Susan Davis (D-San Diego), among other elected officials, were notified of the plume a few days before the general public. Both have taken steps to ensure that the community remains informed, as the initial press conference received little publicity and was attended by only eight civilians.
"It's right up against our district so we are going to be very involved," Faulconer said.
Together the two politicians have organized the upcoming forum for discussion to allow direct communication with the base's commanding officer, Capt. Mark Patton. Faulconer hopes to hold regular meetings to track progress, while Davis has suggested forming an advisory board.
"We will support anything that Councilman Faulconer desires from the Navy in order to keep the public informed," Patton said. He insists that the Navy has never been secretive about the plume, notifying all requisite local and state agencies of its presence.
The San Diego Regional Water Quality Control Board, the state agency charged with enforcing California water codes, has overseen the Navy's progress since 2000. Board engineer Laurie Walsh requested that her agency take over lead regulatory status from the county environmental health department when the leaks were reported because she and the board were already working with the Navy to monitor other, much older releases of hazardous materials into the ground.
"The Navy goes to one regulatory agency instead of two," Walsh said.
As the project manager for the fuel leaks, Walsh reviews the actions taken by the Navy and their contractors, providing guidance and ensuring that the cleanup and abatement are in compliance with law.
"It's very proactive, very timely," she said of the Navy's progress. "Things are being accomplished quite rapidly."
The Navy has successfully managed and reduced the size of the plume since 2001, preventing it from traveling 340 yards downhill and into the San Diego Bay. To date, the Navy has spent $53 million on recovery and remediation.
In addition to pumping out the fuel and water mixture from the ground, Patton said the Navy is monitoring the plume's activity from dozens of wells. And last year, $125 million was approved to replace the entire tank farm with 10 state-of-the-art mega-tanks.
The Navy blames the 70-year-old tanks' aging infrastructure for the three leaks. The thick steel and riveted bottoms are outdated and will be replaced in 2008. The project was proposed in 2000, the same year the first leak was discovered, and approved in 2002. The construction is expected to take four years, by which time Patton hopes to have removed much of the fuel from the ground. When asked why the efforts could not be expedited, Patton said that the environmental assessment alone will take one year.
"There really is no way to accelerate the program," he said. "We are already going as fast as we can, and have been for a couple of years now."
Each week, the Navy removes 45,000 gallons of liquid from the affected area. Roughly 128,000 gallons of actual fuel have been pumped out of the plume, along with a much greater amount of water, which is extracted from the mixture and sent into the sewer system.
The process is tedious and slow. Water is first removed from the soil in key locations to create underground depressions where the plume collects. This technique thwarts the plume's movement and allows for easier extraction, and has been successful so far in stopping the downhill motion of the fuel.
Patton said all the recovered fuel is later resold and reused.
"The plume has not [moved] to the east for over four years now, ever since we started these actions to depress the water table and recover product," he said.
It could be years before the plume is completely eliminated, although that remains Patton's intention. The Navy plans to cautiously employ new technology as it becomes available.
For the moment, the plume has not created health or environmental risks, although it threatens to do both should the Navy lose control of it. Monitoring wells 10-inches-wide and 50-feet-deep allow officials to define the location of the plume and detect shifts in its direction or size. With that information, the Navy maps the plume on a quarterly basis.
Simultaneous monitoring and extraction is rare in situations like this because the latter can lead to false readings. The Navy does both to speed up the process.
"If you are recovering oil, you are affecting the dynamics of the plume and it is very difficult to understand where the plume is at," Patton said. "We are doing both at the same time and we are getting very high marks from the Regional Water Quality Control Board for doing that."
The northern sections of the plume were discovered while monitoring last January. The Navy has since taken the two tanks closest to the area offline and installed hydrocarbon monitoring probes to detect escaping vapors.
"[We] are doing full visual inspections because you can do leak tightness tests, you can do volume checks, you can put probes on it, but until you actually empty the tank, you go in there and you look at the bottom, you cannot absolutely verify that that tank does not leak," Patton said.
The recent discovery has been attributed to the original plume's migration, not new leaks. While Patton understands that nearby La Playa neighbors are nervous that it could take up residence under their homes, he is confident that the Navy can stop further movement.
"Frankly, this is my plume and my problem," Patton said. "The public has my personal assurance as the commanding officer that we will do everything we can."