HINKLEY Officials from the Lahontan Regional Water Quality Board revealed new data Wednesday night that shows the plume of contaminated water has shrunk slightly along the western boundary and has grown slightly in the northern part of the plume.
The public meeting was held by the water board Wednesday night and Thursday night to inform the public about test results from October and November, as well as discuss the health effects of chromium 6.
Lisa Dernbach, a representative for the water board, said an area along the western boundary showed a reduction in chromium 6 levels below the 3.1 parts per billion of chromium 6 considered to be the maximum background level for the area. An area north and south of Alcudia Road showed the chromium 6 concentrations had increased in that area, as well as an area near the intersection of Summerset Road and Santa Fe Avenue. The rest of the plume showed no significant change, said Dernbach.
An investigation into the contamination of the lower aquifer was delayed because of the storms in December, but Dernbach said that it appears the lower and upper aquifer merge into one body of water underneath the surface at the point where a monitoring well drilled into the lower aquifer tested at 20.5 parts per billion of chromium 6 in the October/November testing.
Robert Howd, a scientist who works on setting the public health goals for the Office of Environmental Health Hazard Assessment part of the California Environmental Protection Agency said Wednesday night that he believed the drinking water standard that would be set for California could be somewhere in the range of 5 to 10 parts per billion of chromium 6.
The proposed public health goal from OEHHA is .02 parts per billion, but Howd said it was unlikely the drinking water standard would be set to that level, because of an analysis of over 7,000 California drinking water sources that shows about 33 percent of the sources have above 1 part per billion of chromium 6 in them. In order for the California Department of Public Health to set the drinking water standard, the level has to be both technically and economically feasible.
Members of the water board as well as Howd answered questions from Hinkley residents, many of whom were concerned about the potential health effects of chromium 6.
Howd said the health effects of low levels of chromium 6 such as those found in drinking water in Hinkley are not known, but the body converts chromium 6 into chromium 3. Chromium 3 is an essential nutrient needed to break down glucose in the body. Howd said people should be safe drinking water at the levels found in drinking water wells in Hinkley and that he feels comfortable drinking water at low levels of chromium 6. Howd said he lives in San Jose, which has similar levels of chromium 6 to Hinkley.
Residents brought up several items at the meeting that had been discussed at recent meetings with Erin Brockovich, including the delay in receiving test results from their wells. Dernbach said residents should receive their test results within the next week and a half. The results normally take about four weeks and it has been about five weeks since the wells were tested, Dernbach said.
Jeff Smith, a spokesman for PG&E, said Thursday that the company had received 156 requests for wells to be tested after the December meeting. A total of thirty wells were outside the project area which includes the plume and the surrounding area, as well as a half mile buffer zone and were not eligible for testing. A total of 104 wells have been tested, because some wells were not operational or could not be tested.
Hinkley resident and activist Roberta Walker said Wednesday that she hoped all the wells in Hinkley could be tested for chromium 6.
"If (PG&E) has nothing to hide, why can't they sample (all wells)?" asked Walker.
Smith also addressed other resident concerns on Thursday about the number of property appraisals that have been completed, and said that 25 people have requested property appraisals out of 126 letters that were sent out. A total of eight people have received their appraisals and additional appraisers will be added to speed up the process. Smith also said that all but 10 of the 62 residents who requested bottled water are now receiving it. People who are considered to be outside the project boundary are not qualified to receive the bottled water.
The chromium 6 contamination in Hinkley began when PG&E used chromium 6 to cool tower water for its compression towers in the 1950s and 1960s. The water was dumped into unlined ponds at the site, where it slowly seeped into the groundwater. The plume of contaminated water is now about 2 miles long and nearly a mile wide. PG&E has been ordered by the water board to stop the spread of the plume and clean it up.
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