Introduction Efforts Made Positive Impact Change in Iowa Change Nationally "Deposits" Iowa's Rivers Regulation And Finally Did you know? Findings of a study of water quality in the Raccoon River Watershed were released in Jaunary 2007 by Jerry Hatfield, director of the National Soil Tilth Laboratory in Ames. Hatfield wrote that some have been critical of livestock farmers for the Raccoon River’s elevated nitrate levels. Wrote Hatfield: “To answer that question, we obtained all livestock production numbers for beef and swine since 1949 and computed the amount of manure that would be produced from those livestock populations. What we found was that the amount of manure applied to the Raccoon River watershed is 25 percent less than it was in the early 1970s. This eliminated increases in animal production as the cause for the nitrate concentrations.”