Public Works Corporation Yard Remediation
L A Wood, October 4, 1993
More than five years have elapsed since the City of Berkeley closed its fueling station and confirmed the presence of a leaky, underground, gasoline storage tank. Last month, City Council approved the spending of a quarter of a million dollars for the remediation of the tank site. The cleanup was scheduled to begin this September. However, before work could begin, a decision was made to postpone the removal of the nearly 1000 Cu. yards of contaminated soils. This will allow time for a second review of the work plan by the City of Berkeley's Engineering Department and by an outside consultant, Earth Technology, Inc.
The City's Engineering Department is evaluating an alternative remediation process called bio venting. The bio venting technology is not new to Berkeley. It has been utilized at several privately owned sites. This alternative strategy should prove less costly in the short run. The bio venting remediation process would be less disruptive to the City's maintenance operations and the surrounding neighborhoods. Unfortunately, bio venting will probably be less effective at remediating the old gas station. And that may necessitate repeating the process.
Earth Technology, Inc. has been engaged to perform a treatability study to assess the effectiveness of bio venting on the site. A projected timetable will be established for this treatment in addition to a soil study. Site soils will be measured to determine their permeability and nutrient load. These factors are critical for a more complete cleanup and in reducing the duration of the remediation.
In April of 1992, the Phase I Remediation Report for the maintenance yard was completed. The preliminary evaluation of the site included results on a soil study. It describes the sandy clay as "tight", meaning it has low permeability. This study further explains that "it was considered likely that the contaminated soils would have to be excavated due to their low permeability". It should be noted that soil density has slowed the radiating gasoline plume.
The Toxics Management Department is Berkeley's regulatory force for underground tanks and site closures. With over 150 sites under its jurisdiction, the Toxics Department reports directly to the Regional Water Quality Control Board (RWQCB). RWQCB suggested over a year ago that bio venting might be a possible alternative at the City site. The Phase 1 study also reveals that the City was offered half a dozen alternative remediation plans, including that of no action.
There continues to be an uncertainty surrounding Berkeley's remediation of the Corporation Yard site. Generally, when the routine procedure is followed, the tank(s) is removed and the cleanup commences. However, many contaminated sites, though similar, require an individual work plan. The city-owned maintenance yard is different because the City of Berkeley also is the site regulator. This has contributed to an extremely slow characterization of the contamination, and no cleanup to date.
Aqua Resources, the consultant for Phase 1, concluded that the groundwater has been impacted and appears to have been contaminated by the leaky tank. Furthermore, no remediation of the groundwater is to be considered. There were several reasons given to justify this conclusion. The most notable is the statement that there is no known use for (surface) groundwater in Berkeley.
Today, most of us know little about groundwater and its present state of contamination. We need to begin to recognize the direct links between groundwater, our creeks, and the San Francisco Bay. It has not been that long ago that our City relied on local sources of groundwater for drinking and irrigation. Backyard wells are still commonplace throughout Berkeley, although most are capped.
Over time our municipal reliance on local groundwater has lessened and the level of contamination has risen. One can begin to understand to what extent the environment has been polluted by reading the sign at Berkeley's Marina Pier, It reads: Don't eat the fish!
Berkeley's policies on groundwater have paralleled those of other urban communities. Our municipal shortsightedness to our future city water needs is also having a devastating effect on wildlife and the Bay. A lower drinking water standard has helped limit cleanup costs, but is being paid for with lower water quality. Consider also that this water standard is being used to rationalize an even lower level of environmental cleanup. We limit cleanup costs, slim down work plans, and postpone a critical cleanup for some future generation.
Currently, there is a movement to restore the creek systems in the East Bay. Because creeks are directly linked to surface groundwater and its contamination, any restoration must undergo a rethink. If our present groundwater objectives go unchanged, they will force the covering up of all exposed creeks for public health reasons. West Berkeley's Strawberry Creek Park is only a short distance from the Corporation yard site. A warning of contaminated water posted near the creek is an ever present reminder of this growing crisis.
One certain fact is that the leaching of petroleum hydrocarbons continues its transfer into the groundwater eight to ten feet below the site grade. The contamination has been left unremediated for so long that a critical impact has undoubtedly occurred. Berkeley now should reconsider the practicality of any cleanup at this time.
The sources of contamination at the yard extend far beyond the old fueling station. In the future, a full characterization of the site will be required. The old fueling station is but one of a number of areas at the City facility which will be targeted. The Hydraulic Lift area, Storage area with abandoned sump, and upgradiant contamination have all been identified, but will not be considered for cleanup at this time. A more extensive remediation should most certainly take place sometime later.
A "no action" remediation option was only retained for comparison with the other alternative work plans that Berkeley reviewed in the initial stage of the study. Perhaps it is time to give serious consideration to this option. A "no action" remediation involves a well monitoring program at the site. Public Works has already placed well heads at the site in conjunction with the Phase 1 study. Several additional wells would be required under this plan, but no treatment of soil. The cost is only about 1/5 of the excavation and soil removal work plan.
Remediate to the fullest extent feasible. This should be the call. Disturbing the site seems senseless at this point and perhaps would extend the residual pollution. It is time to take the more pragmatic approach. The "no action" alternative has become the more feasible choice. It is better suited to the present dynamics of the site, and "no action" certainly is an approach better suited to Berkeley's real groundwater policies than is indicated by the name Eco-City".
Corpyard cleanup may wait for advanced technology
Shannon Morgan, Berkeley Voice, September 9,1993
Plans to excavate 1,000 cubic yards of contaminated soil at the city's corporation yard this month have been scrapped in favor of removing toxins through new technology.
The city had decided more than three years ago to go ahead with remediation of the soil around underground gasoline storage tank areas in order to comply with Bay Area Regional Water Quality requirements.
But with a cost of $250,000, potential health threats from fumes and disruption to the surrounding residential neighborhood, the Public Works Department and Toxic Management Program are now recommending that the city use a bioventing method to remove the toxins without excavating the soil.
"It's not the least bit disruptive and there's no safety hazards about it. It seems like a much more reasonable approach," said project manager, Jeff Egeberg, manager of engineering.
Under the method, an underground well would placed in the middle of the contaminated soil and would be connected to a pump and blower apparatus the size of an office desk that would sit above ground. The pump would release oxygen into the soil which would then migrate through the soil and activate microorganisms to decompose contaminates into harmless materials.
At a cost of $10 per cubic yard, rather than $250 per cubic yard for excavation, city staff say the method is not only more efficient but would save the city $240,000 if the city council approves the plan later this month.
Egeberg said city staff began to reexamine the issue in light of disruption from 250 truck loads of soil out of the west Berkeley neighborhood, possible health threats to city employees and neighbors from toxic fumes and the requirement to move the city's fleet of maintenance vehicles in order to complete the job.
Area residents, who have been actively pushing for the removal of toxins from their neighborhood for the last two years, have said they would welcome the change of plans, according to community organizer L A Wood.
"The community was concerned about the disruption that would be caused by excavation. We don't want the city to spend $250,000 if they don't have to and it fits into the scheme of what Toxics Management and the Regional Water Quality Board require," Wood said. Wood is one who has worked hard to ensure the removal of contaminates, but also wants to make sure that doing so doesn't cause more harm than good.
"They said there was going to be this odor from excavation with a lot of chemicals floating around in the air, because they were going to pile the soil up and let it the contaminates evaporate before moving it offsite," he said.
While the new method would eliminate air pollution, Wood said he is waiting for a report from the city on its impact. "I wanted to know more about it. The fact that Berkeley has other such systems operating right now is encouraging," he said.
Egeberg confirmed that private industries are using the method as a cheap and effective alternative to moving tons of dirt.
"Alternative methods of treating soil in place have come a long way. We've met with an expert in environmental programs who advised that this is a good candidate of bio-venting," he said.