Today (Tuesday) a new UC Davis nitrate study was released (click here or image below) blaming nitrate contamination of ground water on agriculture.
What a surprise!….This is just one day before the Central Coast Regional Water Quality Control Board is to vote on controversial new rules on agricultural pollutants, including nitrates, pesticides and sediment, from aquifers and surface waters.
Of course, the press (click here) is spinning the draft study as showing an alarming problem. Nitrate in ground water is indeed a problem in agricultural areas…and the study is detailed and contains a lot of useful information. The article suggests that astronomical concentrations of nitrate have been found in public drinking water systems which will cause all sorts of bad health effects. Private wells have been effected, public water system wells not very much…..but read the study, not the press. For example:
“From 2000 to 2011, the median nitrate concentration in the Tulare Lake Basin and Salinas Valley public water supply well samples was 23 mg/L and 21 mg/L (as nitrate), respectively, and in all reported nonpublic well samples, 23 mg/L and 20 mg/L, respectively. In public supply wells, about one in ten raw water samples exceeds the nitrate maximum contaminant level (MCL). Nitrate concentrations in wells vary widely with location and well depth. More domestic wells and unregulated small system wells have high nitrate concentrations due to their shallow depth. The highest nitrate concentrations are found in wells of the alluvial fans in the eastern Tulare Lake Basin and in wells of unconfined to semi‐confined aquifers in the northern, eastern, and central Salinas Valley. In the Kings, Kaweah, and Tule River groundwater subbasins of Fresno and Kings County, and in the Eastside and Forebay subbasins of Monterey County, one‐third of domestic or irrigation wells exceed the nitrate MCL. Consistent with these findings, the maximum nitrate level, measured in any given land section (1 square mile) for which nitrate data exist between 2000 and 2009, exceeds the MCL across wide portions of these areas. Low nitrate concentrations tend to occur in the deeper, confined aquifer in the western and central Tulare Lake Basin.”
Judging from its content, this was a very expensive study that has alot of useful information in it. This type of study could be used to justify new regulations, or used to argue against new regulations, depending on ones point of view. Whether regulations set by the Central Coast Regional Water Quality Control Board will have any impact at all on solving such a problem is certainly open to vigorous debate.