EPA: St. Joe River pollutes Lake Michigan
By MOLLY McVOY
St. Mary's Editor
A study by the Environmental Protection Agency will report that the St. Joseph River is contributing pollutants to Lake Michigan later this year, officials from the EPA said this week.
The study Lake Michigan Mass Balance, founded in 1994, discovered two toxins that are particularly prevalent in the river. High levels of atrazine and trans-nonachlor compounds were found in the water.
"St. Joe is one of the two major contributors of atrazine," said Glenn Warren, the technical lead for the project.
Atrazine is the most common herbicide used in the United States for corn and sorghum production. It is known to disrupt the endocrine system in humans and is currently being looked into as a cancer-causing agent. In one of the samplings of the river, atrazine was found at chronic toxicity levels. At these levels, prolonged exposure to water from the river would effect human health.
"[Atrazine] is such a widely used herbicide," said Christopher Dunlap, an analytical chemistry professor at Saint Mary's. "The fact that it is showing up in our rivers is scary."
Trans-nonachlor compounds were used primarily as insecticides in the middle part of this century, but have since been eliminated from commercial use. Chlordane compounds, as trans-nonachlor compounds are also known, can disrupt the functioning of the endocrine system and cause vision and digestive problems. The study found that the St. Joseph River and the Grand River were the two biggest contributors of trans-nonachlor compounds.
In addition to the above compounds, the study also looked into mercury deposits and PCBs, components of rubber and plastic products, in an effort to determine where they were entering the lake. The data that is collected and analyzed will be used to better understand how to reduce these toxins.
"If we want to reduce the toxic contaminants entering the lake, we need to know where the main sources are," Warren said. "We need to know if they're coming from the air or if the rivers are the main source. We also need to know what rivers are the main source."
The study found low levels of both Mercury and PCBs in the St. Joseph River. The reasons for higher levels of the atrazine and chlordane compounds are not completely understood. It is likely that the popularity of corn farming in the area contributes the levels of atrazine. The type of soil in the area may also be a factor.
"The concentrations may have to do with the geology of the soil in the area," Dunlap said. "The St. Joe River runs through a lot of dunes. These sandy soils may contribute to a lot of run-off."
Six years after the beginning of the study, data collection is nearing completion. The end purpose of the study is to produce models that will allow scientists to predict how effective their attempts are at reducing pollutants. The modeling will take an additional year to complete, according to Warren. When the modeling is complete, there will be a better understanding of where these toxins are coming from, how they are interacting with their environment, and what steps can be taken to reduce or eliminate them.
"The goal is to allow environmental managers to ask questions about how effective their methods will be," Warren said. "It's a way of prioritizing our efforts."
All News Stories for Wednesday, September 6, 2000
