Plan to Poison Pike in Lake Davis

* Re “Protest Fails to Derail Plan to Poison Fish,” April 30: It’s hard for me to conceive how introduction of rotenone, trichloroethylene (TCE) and other chemicals into Lake Davis will not have “long-term health effects,” as state officials contend. Although it will likely kill off the aggressive pike population as intended, what comes to my mind concerns the introduction of these chemicals into ground water beneath the lake and their potential to migrate toward water wells in the vicinity in the coming decades.

From my perspective as a hydrologist, it is ironic to see this possibility arise, especially since state and federal regulations exist to control concentrations of hazardous chemicals in ground water through mandated cleanup procedures and limits on surface discharges. On a current project, millions of dollars are being spent annually to remove what amounts to a few barrels of TCE in ground water, inadvertently and sporadically discharged over 40 years ago. The cleanup operation could take 20 years or more to reduce TCE levels in ground water to an incredibly small concentration of five parts per billion.

State officials have probably analyzed the issue, planned some precautionary measures and are otherwise convinced that a similar problem will not occur beneath Lake Davis. I certainly hope so. Nevertheless, something still seems a bit fishy to me.

ANDREW F.B. TOMPSON

San Ramon, Calif.