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Keeping SLAC's Water Clean

Water, water everywhere, but did you ever stop to think about where it goes and how we ensure that it is clean? Water flows from SLAC in three ways; rain or storm water is routed offsite through drainages and pipes, industrial and domestic wastewater is directed to a treatment plant through the sanitary sewer system, and groundwater slowly creeps through bedrock below SLAC.

San Francisquito Creek, running south of SLAC, is home to many native species, including shorebirds from all over the South Bay and fish like the steelhead trout. All stormwater runoff from SLAC flows, untreated, to San Francisquito Creek. A mission of the Environmental Protection Group is to ensure SLAC runoff contributes to the healthy flow of stormwater into the creek and down to the San Francisco Bay.

"An important aspect of our work is to help SLAC minimize impacts to the creek from our operations so it remains a healthy environment for the flora and fauna," says Susan Witebsky, environmental protection group leader in the Environmental, Safety and Health (ES&H) Division.

SLAC has a Storm Water Pollution Prevention Plan that requires monitoring of runoff as well as operations, and SLAC reports the results annually to the California Regional Water Quality Control Board. Best Management Practices are applied to specific operations to minimize the potential for impact.

Witebsky says that SLAC is not allowed to put anything other than rain water into the storm drain system. "Not even drinking water, because the chemicals in it may be fine for us, but not for the fish," she says. In fact, the environmental protection group's motto is "Nothing but rain in the drain."

ES&H also monitors the level of metals in SLAC's sanitary sewer discharge. For instance metals, such as copper, enter the sewer system when workers flush pipes to clean them. ES&H requires SLAC employees to collect this cleaning water in tanks, whenever feasible, and take them to the Metals Finishing Pre-treatment Facility, which is associated with the plating shop. The final destination of sanitary sewer water is a treatment plant in Redwood City. The treatment plant provides treatment of water for metals before the water is discharged to the Bay.

Finally, ES&H monitors ground water. There are more than 100 monitoring wells for ground water at SLAC, most of which are sampled twice a year and reported to the Regional Water Quality Control Board.

More information about water treatment can be found at the ES&H website.

María José Viñas, SLAC Today, July 10, 2007