Tests Rule Out Dredge Spoil Use at Aquatic Park

By Riya Bhattacharjee
Thursday October 22, 2009 - 09:17:00 AM

After nearly two years, the mounds of dredge spoils dotting Berkeley Aquatic Park’s western shoreline might finally be removed, if a report by the Berkeley Public Works Department is anything to go by. 

Initial test results have ruled out their reuse inside the park. 

In Nov. 2007, Public Works illegally dredged the Aquatic Park lagoon and dumped 30 truckloads of spoils on a popular birdwatching and bird-foraging site, angering environmentalists—including the Sierra Club—and park regulars who were concerned about toxicity levels. 

Since then, passengers taking I-80 may have noticed the tarpaulin-covered eyesores and dismissed them as construction rubble or garbage. 

Public Works officials submitted a revised dredging plan to the City Council in February 2008. They said they would ask the regional water board and related agencies for the correct permits to dredge the lagoon to clean the five tidal tubes that connect the lagoon to the bay, to improve water flow, but first they would have to figure out whether the spoils could be reused in the park. 

Public Works staff subsequently told the City Council that they were recommending that the spoils not be used on the site but instead be taken to a dumping site. 

In June 2008, the Berkeley City Council asked city staff to conduct additional tests to see if the spoils could be reused in the fill areas designated in the Aquatic Park Improvement Plan. 

An Oct. 13, 2009, report to the City Council by city Public Works Director Claudette Ford said the spoils have to meet the standards for wetland reuse—which are considerably higher than those for other purposes—as mandated by the Regional Water Quality Control Board, before they can be reused at Aquatic Park. 

The water board recommended a three-tier testing approach to determine the soil’s environmental risk assessment, which Ford described as “quite rigorous and extremely costly.” 

At least four of the first batch of test results for chemical concentration were above the maximum acceptable San Francisco Bay ambient levels, according to Ford’s report, eliminating the need for the next two steps. 

Public Works Supervising Civil Engineer Lorin Jensen told the Planet that specifics of the test results have not been released to the public yet. 

Ford’s report said that “the material is unsuitable for reuse at the park,” and it is unlikely that the water board will determine otherwise. 

Ford contended that, because the test results were above the accepted San Francisco Bay ambient levels, it would be too expensive to do the other tests, since the water board has the final say and it uses ambient levels as the main criterion for determining suitability. 

Water Resources Control Engineer Brian Wines, who handles dredging permits at the regional level, said the test results had not been submitted to the water board yet. 

Wines said that, although the agency placed a lot of importance on ambient levels, “it reviewed each level of exceedance” before passing a verdict. 

Public Works officials are in the process of performing additional tests to determine the appropriate disposal classification and location for off-site disposal. 

Ford said that the cost of hauling and disposing of the spoils could vary greatly and would depend on the results of the tests. 

She added that the cost of disposal would probably be higher than the cost of reuse. Earlier estimates put that cost at $210,000. The report said that the city would try to finish disposing of the spoils before the start of the wet weather season.