Good News: Cleaner Water

A recent article in Environment & Climate News caught my attention. It was titled, "Pesticide, Herbicide Concentrations Decline in Corn-Belt Waterways." James M. Taylor, a prolific writer at the Heartland Institute, wrote a short piece and quoted from the U.S. Geological Survey (USGS) National Water-Quality Assessment Program studying U.S. streams, which claimed "…nine of eleven pesticides and herbicides are declining, one is remaining steady and one is increasing."

Because EPA, through the National Cotton Council decision (www.nasda.org/File.aspx?id=23370) is attempting to gain control over our spraying and possibly strangle Midwestern crop production, I thought this was good news for a change. (Disclosure: On occasion I write articles for Environment & Climate News.)

The purpose of the USGS report was to assess trends in concentrations of commonly occurring pesticides in certain streams in the Corn Belt. The report claims our agricultural region accounts for a substantial portion of national pesticide use. USGS wanted to evaluate the performance and application of its statistical trend assessment methods because it wants to apply these methods to other regions.

The study reviewed data from 31 sites from various drainage areas throughout the Midwest. The sites were distributed among 5 major drainage systems. USGS claims that our corn belt is one of the most intensively farmed regions in the country and included drainage systems that included Iowa, Illinois, parts of Indiana, Minnesota, South Dakota, Nebraska, Kansas, Missouri and Ohio. The study reviewed two time periods from 1996-2002 and from 2000-2006. The study used two statistical methods during these two time periods to study atrazine, acetochlor, metolachlor, alachlor, cyanazine, EPTC, simazine, metribuzin, prometon, chlorpyrifos, and diazanon.

The report concluded "Analysis of flow-adjusted trends showed that most of the pesticides assessed were dominated by concentration downtrends in one or both analysis periods. Atrazine, metolachlor, alachlor, cyanazine, EPTC, and metribusin – all major corn herbicides – showed more prevalent concentration downtrends during 1996-2002 compared to 2000-2006."

This report prepared by USGS is extremely detailed and data driven, but its clear conclusion is that pesticide and herbicide residues in water are "predominately downward during 2000-2006." The report claims the downtrend in concentrations and water correspond to less use and new product forces "…that reduce their use in the Corn Belt during all or part of the study period." 

USGS indicated that other factors may be causing less pesticides and herbicides concentrations in water such as conservation tillage and the use of buffer strips.

USGS might think about obtaining information from USDA, or work with Dr. Jay Lehr, who is quoted in the February issue of Environment & Climate News. Dr. Lehr summed up the massive USGS data and report and provided probably the best answer for the decline of pesticides and herbicides in our streams when he said, "Much of this improvement is a result of the increase in the practice of reduced tillage farming, which allows previous crop residue remaining on the land to capture both water and pesticides that previously ran off acreage into nearby water courses."

And, Dr. Lehr is not even a farmer!