Hundreds of thousands of Wisconsin residents are at risk of illness from waterborne pathogens in private and public drinking water supplies.
The State of Wisconsin in the USA is known as America’s Dairy State as it is one of the largest producers of dairy products for the entire country. In Kewaunee County alone, large dairy farms contribute the bulk of the more than 555 million gallons of slurry (liquid manure) that are spread on the county’s fields each year.
Due to the extensive dairying activity and the resultant need for the disposal of huge quantities of slurry, many private water wells and some municipal water reservoirs are now contaminated with pathogens, nitrates and other contaminants almost all the result of intensive dairy farming.
The facts are frightening and should be a warning signal (canary in the coalmine!) to Ireland and particularly the Golden Vale where many farmers are expanding their dairy herds to increase milk production.
Between 2007 and 2010, an estimated 18 percent of 3,868 private wells in Wisconsin tested positive for coliform bacteria (an indicator of disease-causing bacteria, viruses or parasites) by researchers with the state Department of Health Services. That translates into as many as 169,200 of the 940,000 Wisconsin households served by private wells exposed to disease-causing pathogens. However, in a more recent study and testing carried out by the University of Wisconsin at Oshkosh showed the serious extent of the problem in Kewaunee County alone. More than one-third of the 320 wells tested were found to be unsafe to use. Those 110 wells had unsafe levels of coliform, E. coli or nitrate as a result of the intensive dairy farming in this county.
The water contamination problem also plagues municipal water systems where coliform bacteria accounts for most of the violations of health standards recorded each year. The 2014 Department of Natural Resources drinking water report on the state’s public water systems found 3.7%, or 420 of the 11,420 systems, had detectable levels of coliform. The report said those 420 systems serve about 92,290 people. Most of the violations, 351,were in small public water systems serving motels, restaurants, churches and campgrounds throughout the State. Any amount of coliform is considered unsafe. Of the wells found to be unsafe by the DNR testing, 27 percent had coliform and five wells, or 2 percent, were contaminated by E. coli, which can come from human or animal waste.
Water contamination by pathogens is of special concern because unlike contamination by heavy metals or chemicals, pathogens can sicken people after just a single exposure. The gastrointestinal illnesses that result can be life-threatening for people with weakened immune systems such as the sick, elderly and infants. Pathogens such as bacteria, viruses and parasites are the most frequent causes of illnesses in private water systems, according to the U.S.Centers for Disease Control and Prevention.
Cow manure slurry is a veritable stew of more than 150 pathogens that can make people sick, according to a report from the National Association of Local Boards of Health and the U.S. Centers for Disease Control and Prevention.
These pathogens include E. coli, Salmonella, Giardia and Cryptosporidium. All can cause severe diarrhea and can be deadly for those with weakened immune systems. Infants and young children, pregnant women, the elderly, people who are HIV-positive and those who have undergone chemotherapy – about 20 percent of the U.S. population – are most at risk.
In many cases, households using water from private wells may be ingesting pathogens unknowingly because, according to the state health department, only about 16 percent of owners statewide have them tested.