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An accidental spill of 630 gallons of water contaminated with chrome 6 that was being pumped out of the skate bowls at Harrison Field last Sunday has flowed into the Bay. 

Environmental experts said the spill resulted in a relatively small amount of chromium 6 reaching the Bay and it is likely that there would be no significant ecological impact. 

Secor International, an environmental engineering company, was in the process of pumping contaminated water out of partially constructed skate bowls when an improperly installed sump pump failed to shut off after a 20,000 gallon, above-ground tank had become filled.  

The water, spilling over at a rate of approximately seven gallons per minute, flowed into a storm drain on Harrison Street and into the Bay near the end of Gilman Street. 

According to Nabil Al-Hadithy, the city’s hazardous materials supervisor the water originally contained approximately .1 to .15 milligrams per liter of chromium 6, a carcinogen that is dangerous to humans if ingested or inhaled. Al-Hadithy said the chromium was diluted when it entered a storm drain that contained several hundred gallons of water. 

“Tests were done at the point the water flowed into the Bay and the ratio was .004 milligrams of chromium 6 per liter of water,” Al-Hadithy said. 

He said there was no exposure to humans, and tests are being conducted to determine if there are any ecological consequences to the Bay. 

Dr. Khalil Abu-Saba, environmental specialist with the San Francisco Regional Water Quality Control Board, said there would probably be little ecological effect.  

“The limits on chrome 6 in water is 11 parts per billion for fresh water and 50 parts per billion for sea water,” Abu-Saba said. “If .004 per liter is accurate then the spill is below what would be considered safe for fresh water.” 

Dr. Angus McGarth, principle geochemist with Secor, said they have taken precautions to ensure against any more accidental spills. “I pride myself on cleaning up contamination, not contributing to it,” he said. 

Hesaid the cost of the spill in additional time and testing was about $2,500, for which Secor is taking responsibility. 

The Toxics Management Division discovered the contaminated water in November when groundwater poured into two pits that were being excavated for skate bowls at Fourth and Harrison streets. The contaminated water had been drawn into the bowls from a nearby chrome 6 plume that the city had known about since 1990. 

The city stopped construction of the park when the contaminated water was discovered. 

The plume was the result of a leaky storage tank located at Color Tech two blocks away.  

So far the city has paid approximately $150,000 in costs related to the clean up of the contaminated groundwater. 

The Parks and Waterfront Department plans to continue the construction of the skate park and recently began to accept bids for a new design that will raise the skate bowls above groundwater depth with is about 9 feet below the surface.