From December 15, 2005
Studies
Find 1 in 5 Wells in Dakota County Contaminated
(Beyond
Pesticides, December 15, 2005) One
in five wells in Dakota County, Minnesota has tested positive for unsafe
levels of pesticides and other harmful chemicals. Researchers found
levels of nitrates and pesticides that exceeded state safety standards
for drinking water in 14 of the 68 wells tested. 42 of the wells tested
showed lower levels of the chemicals, while only 12 wells showed no
contamination at all.
The wells tested are part of a voluntary multiyear study to track underground water quality in the area. Researchers found similar test results earlier this year, and have issued information to the well owners about bottled water, filters and other options.
Nitrates, one of the major pollutants found in the well water, can cause “blue baby syndrome”, a condition where babies cannot process oxygen properly. The presence of nitrates also indicates possible bacteria, such as coliform, which can come from, among other things, fertilizers used on farms and residential lawns.
Several pesticides were also found in the water including alachlor, atrazine, metolachlor and cyanazine. Alachlor is a probable carcinogen as well as a reproductive and developmental toxin. Atrazine, a pesticide used on a variety of crops including corn, sugarcane and Christmas trees, has been linked with cancer, birth defects, and neurotoxicity. Atrazine is also a suspected endocrine disruptor. Metolachlor, an herbicide used on everything from cotton to tomatoes for processing, is also a possible carcinogen and a suspected endocrine disruptor. The final pesticide identified in the water, cyanazine, is not only a possible carcinogen and suspected endocrine disruptor but is no longer allowed to be sold in the United States, however it is still used by corn growers.
Dakota County Commissioner Joe Harris commented that enough wells contained chemicals that it would be necessary to inform all households in the county with private wells - about 8,000 total - that their drinking water may be risky to consume. Harris said the county will recommend that these residents drink bottled water, or install a reverse osmosis filtering system.
The county environmental management supervisor, David Swenson, acknowledged that the county had found high cyanazine levels in one in five municipal wells in the city of Hastings. Wells were shut down in the city in September as a result.
Source: Star Tribune