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In the Valley
SUPPLY-SIDE SELENIUM
A plan to separate selenium-tainted drainage water from wetland refuge supplies has been creeping ahead since last spring, but if all six water districts in the Grasslands area don't participate, it won't work, says the Central Valley Regional Board's Joe Karkoski. The plan would redirect the drain water away from channels serving refuges and then down Mud Slough and the San Luis Drain, whose potential reopening, however environmentally beneficial, remains a political red herring due to the drain's starring role in the Kesterson duck Armageddon. Despite Congressional caution, however, negotiations continue between the Regional Board, environmental groups, farmers and water districts. Currently, the talks are revolving around three issues: how to get all the drainers to sign on (several remain reluctant); how to address contaminated sediments in the drain bottom, whose 20-30 ppm of selenium could be remobilized by reintroducing flows to the now idle drain (sending more selenium downstream to the Delta); and at what level should selenium load reduction milestones, which regulators would like to set for the next five years, be pegged?
If these issues can't be resolved, Karkoski says the Regional Board may have to adopt and enforce a selenium standard for waterways carrying Grasslands drainage. To protect the San Joaquin River, into which these waterways drain, Karkoski's been laying the technical groundwork for a Board Basin Plan amendment that would set a selenium TMDL (total maximum daily allowable load) for the river. His amendment will be reviewed by the Board as early as this March. In the meantime, Karkoski says he's working on the "trickier" part, a "justifiable" TMDL implementation plan. This may include a tradable discharge permit system developed by the Environmental Defense Fund. For implementation fodder, Karkoski is also reviewing the recommendations of the San Joaquin Valley Drainage Program - a late 1980s consensus- and information-building response to the Kesterson tragedy. In addition, he's evaluating how effective the Board's existing Basin Plan approach on selenium - voluntary source reduction - has been.
Whatever the implementation plan approach, any kind of comprehensive selenium reductions could be costly. "We're at a turning point," says Karkoski. "When it comes right down to it, it's a matter of how much protection can we afford?" Contact: Joe Karkoski (916)255-3097
VACU-BOOM BOMBS
Though a mobile cleaning unit hosed down, sucked up and vacuumed out runoff from three Sacramento gas stations ten times last winter, a two-year before and after study indicated that this high-tech BMP did not reduce pollution. The study, funded in part by the S.F. Estuary Project, compared pre-BMP 1992-1993 wet season runoff with post-BMP 1993-1994 runoff. In addition to the $600-a- pop visits from the mobile clean-up unit, study and station managers invested in litter control, storm drain stenciling, spill clean-up materials, public notices and employee training.
According to a newly released study report (see Now in Print), the one BMP with the most significant chance to affect runoff quality was the mobile high-pressure water cleanings. But although field crew observations confirmed that the cleanings - in which runoff was collected with a boom and then vacuumed and pumped into an on-site sewer cleanout - removed a significant amount of pollutants, results showed no statistical difference in the pre- and post-BMP concentrations (except for oil and grease whose levels measured higher after the BMPs).
Researchers speculate that the cleanings may have made more pollutants "available" for wash off by the next storm or clean up. Contributing factors may have included rough surface texture, incomplete wash off after cleaning or heavy pollutant buildup. The study showed that build up occurs during dry periods, and runoff concentrations reflect the length of the buildup period.
Study manager Jon Goetz of Sacramento County Public Works thinks the fact that it rained more during the 1993-1994 season may have muddied the results. "A wet year does a better job of cleaning," says Goetz, who recommends limiting any further studies to one rain year in which three gas stations serve as reference sites and three others try BMPs. Goetz also thinks the results hint that regional solutions, such as off-site stormwater detention basins, may be more effective and less costly than on-site high-pressure hose-downs. "If we force gas stations to do one BMP, such as mobile cleaning, it sets an expensive precedent for every other station, road and parking lot in the county," says Goetz. Contact: Jon Goetz (916)552-8913 10/93
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