Patches of sticky silt--dubbed “goop” by environmental experts--have nearly tripled in size since their discovery three years ago south of outfall pipes at the San Onofre Nuclear Power Plant and are smothering sea life along the ocean floor, a panel of scientists reported Wednesday.
“It kills whatever is below it,” said William W. Murdoch, a UC Santa Barbara biology professor who heads a three-member scientific panel charged by the California Coastal Commission with monitoring environmental changes around the plant.
But Murdoch, in an oral report to commissioners meeting here Wednesday, stopped short of blaming the power plant for the spreading material, adding that the scientific panel is divided on what causes the silt to form and smother a large kelp bed south of the outfalls.
The silt, which extends a little more than a third of a mile offshore, has not been tested for radioactivity, but Murdoch said he does not believe it is radioactive.
Although Murdoch said he personally believes that the evidence points to San Onofre’s water cooling system as the origin of the silt, the panel will not release its conclusions on the matter until it issues a final study in June detailing the environmental impacts of the seaside power plant.
That final study will culminate more than 14 years and $40 million in scientific research to chronicle the environmental changes around the intake and outfall pipes leading to the three reactors in California’s largest nuclear power plant.
The plant takes in two million gallons of ocean water every minute to help cool its nuclear reactors before discharging it back into the Pacific at temperatures averaging 19 to 22 degrees hotter than the surrounding water, where the temperature ranges from 57 to 68 degrees, Fahrenheit.
Opponents of the plant have long predicted that the hot water discharged by the cooling system would cause havoc in the ocean, wiping out the vital supply of plankton and creating a “desert” along an area of ocean floor that once thrived with marine life.
Those concerns, plus a lack of hard data, prompted the Coastal Commission to form the three-member panel in 1974, when it granted a request by Southern California Edison Co. to expand the power plant from one to three reactors. Since then, the scientific panel has been studying the data and debating its significance.
Murdoch’s report on Wednesday served as a sort of prelude to the final scientific report expected in June. Although incomplete, Wednesday’s update indicated that years of studies have shown that the power plant has produced some environmental surprises:
- Despite the dire predictions of environmentalists, the water discharges from San Onofre have not wiped out the nearby plankton population. Composed of phytoplankton, tiny plants, and zooplankton, small animals drifting in the sea, the organisms form the basis of the marine food chain.
Murdoch reported that studies show that the amount of zooplankton has remained unchanged around San Onofre, although the underwater intake pipes suck in nearly 1,000 tons of the tiny animals each year. The amount of phytoplankton has actually increased around the underwater outfall pipes, Murdoch reported.
One of the scientists on the panel, however, took issue with the conclusions about plankton. Rimmon Fay, who represents environmentalists on the panel, said after the meeting that he disputes the way the panel tested for plankton, taking samples from areas of the ocean not directly affected by the San Onofre cooling water plume.
Thus, he claims the results are misleading and that the plankton population has probably declined more than his colleagues realize.
- While the plankton are thriving, the scientists found that the power plant had a “major negative effect” on the population of midwater fish.
As far out as three kilometers from the plant, the number of queenfish and white croaker were found to decrease by 50% or more over the period of time that the three reactors were fired up.
Part of the decrease can be traced to the number of fish that are sucked into the San Onofre cooling pipes and are killed, according to Murdoch’s interim report. Murdoch stressed, however, that these numbers were not enough to account for the drop in midwater fish population, a phenomenon the panel will continue to study.
- The population of bottom-dwelling fish--which includes older queenfish and white croaker--actually increased in an area more than one kilometer around the power plant. Total weight of the fishes increased from 60% to 100% during the 14 years of the study. The increase in bottom-dwelling fish was not a surprise, however, and had been predicted before the San Onofre expansion.
The keystone of Murdoch’s report, however, was the update on the “goop,” which he said is settling on a kelp bed just south of the outfalls. The bed, which measures one square kilometer, is of prime concern to the scientists and will be examined before the final report is released.