Nitrogen and pesticides are found in drinking water:
In the spring of 2016, the Pollution Control Agency issued a press release and said in part:
“(n)itrate is one of the most common contaminants in Minnesota’s groundwater and comes from sources like agricultural fertilizer and animal manure. Up to 60 percent of the groundwater samples from monitoring wells in central Minnesota are contaminated with nitrate well beyond the safe drinking water standard.”
The Department of Agriculture’s own Minnesota data shows that where there is nitrogen in groundwater, there likely will be pesticides. And, if there is a lot of nitrogen, then it is likely that there will be a lot of pesticides. Unfortunately nitrogen is not a perfect indicator of pesticides. The Department of Agriculture’s data show that there can be pesticides even when there is no nitrogen present.
Even if a private well is then tested for a wide range of pesticides and all are found to be below the health risk limit, it would be wrong to let the well owner assume that the water was safe. The Minnesota Department of Health may be able to tell well owners what might be a safe level of one pesticide, but where there are multiple pesticides, current science can’t tell us about the cumulative or compounding effect of pesticides even when individually some or all may be at very low level.
It is unfair that well owners are put in the position of needing to clean up water that they did not contaminate or to otherwise find an alternative source. Rep. Rick Hansen has a bill to provide help. Providing help, especially to families with children, should be a top Minnesota priority.
Minnesota’s Department of Health is not on top of agricultural contaminates
In its groundwater water-testing program The Minnesota Department of Agriculture looks for more than 130 pesticides and associated break-down products. Even though Minnesota is an agriculture state, MDH typically only tests for a limited number of pesticides–20 is the number given to House Research–in municipal drinking water wells.
MDH does not test for any of the ubiquitous systemic pesticides including neonicotinoids. They are water soluble, persistent and toxic to water creatures. They are also found in some foods so accounting for cumulative impacts is a necessity.
With the exception of one break-down product test required by EPA, MDH does not test for the multiple break-down products of pesticides like Atrazine that are commonly found in our waters. It is generally understood that break-down products can be as toxic as the parent, perhaps more so. Further, break-down products and their parent may have a cumulative effect so they should not be ignored.
For example, MDH’s health based standard for Atrazine is 3 parts per billion, a standard set by the Federal government in 1992 and reevaluated in 2003. Since then studies link Atrazine to endocrine disruption, not just in animals, but in humans.
In 2000, Minnesota changed its health based standards law. The 2000 law, Minnesota Statutes 144.0751, requires MDH to revise standards to “include a reasonable margin of safety to adequately protect the health of infants, children…taking into consideration risks to…reproductive development and function…development of the brain and nervous system, endocrine (hormonal) function….”
Science has changed. It is far more sophisticated. The basis of our health standard changed. Yet, the standard for Atrazine has not changed. The MDH still does not test for–or add in–Atrazine’s break down products.
Source water monitoring of contaminates is very limited
The pesticides tests that MDH is doing are on “finished” water. Its testing of source water has been very limited. Source water should be tested in order to understand what needs to be checked in finished water. Further, if source water is not tested, then it seems that prevention is not a goal that is being pursued.
The lack of taking measures to prevent drinking water pollution is also evident in the limited follow through on source water protection plans and the increasing pollution in drinking water systems. The MDH has determined that over 1.2 million acres of land should be in municipal wellhead protection areas. Of that, over 350,000 acres are at particular risk because of geology. The Department reports that only a very small percentage have been permanently protected.
This Mississippi River is the drinking water source for over a million Minnesotans who reside in St. Cloud, Minneapolis, St. Paul and many suburbs. MDH has not produced a source water plan protecting the Mississippi similar to the plans designed to protect municipal wells.
Clearly, our source water protection plans need to be reevaluated and reformed. They are not protecting source water. I have introduced a bill, that starts that process.