CONCENTRATION AND SOURCES OF FECAL AND ORGANIC POLLUTION IN AN AGRICULTURAL WATERSHED¹

Abstract

Fecal contamination and organic pollution of an agricultural drainage in northeast Indiana was high. Bacterial counts (total coliform, TC; fecal coliform, FC; and fecal streptococcus, FS) and biochemical oxygen demand (BOD) were used to assess waste concentrations. Coliform counts indicated that sections of the drainage receiving septic effluent had waste concentrations far in excess of public health standards (mean FC = 550,000/100 ml). Areas of drainage remote from septic tank pollution were found to occasionally meet federal public health standards for whole body contact recreation but generally these areas had twice the allowable limit of 200 FC/lOO ml. Bacterial contamination was highest during runoff events when the median values for TC, FC, and FS were 5,3, and 17 times greater, respectively, than the median values during low stream discharge. Surface flows carried contaminants from unconfined livestock operations and fecally contiminated sediment was transported by high waters. During one runoff event a BOD loading of 36.7 kg/km2 was recorded and the peak BOD concentration observed was 16 mg/l. A discharge of liquid manure from a confined livestock operation caused a major fish kill. Pollution from septic tanks and unconfined livestock is greatest at high stream discharge when dilution reduces the impact on aquatic life. (KEY TERMS: bacterial pollution; BOD; agricultural runoff; coliform bacteria; fish kill; water pollution sources.)

Bacterial Transport from Agricultural Lands Fertilized with Animal Manure

“…An increase in yield was also observed for all the treatments except CO. Although not significant, this increase in EC concentration and yield is consistent with observations made in previous studies (Dudley and Karr 1979;Kunkle 1970; Robbins et al 1971). The presence of bacteria in the runoff from the CO treatment is again attributed to the cross-contamination from other treatments.…”

“…The increase in FC concentration and runoff volume resulted in increased FC yields from the dairy manure treatments. The increase in concentration coupled with increased runoff volume and peak runoff rate have been observed in previous studies (Dudley and Karr 1979;Kunkle 1970;Robbins et al 1971). These results are particularly significant as they show that the release of bacteria from dairy manure is gradual, and that the bacterial contamination from animal manure treatments can extend over a period of time, unlike nutrient contamination where significant losses of nutrients were observed during the first simulated rainfall event (Mishra et al 2006).…”

Biological Integrity: A Long‐Neglected Aspect of Water Resource Management

“…Even more complex community-based indexes like the Hilsenhoff index for benthic macroinvertebrates (Hilsenhoff 1982(Hilsenhoff , 1987 are primarily sensitive to domestic effluents. Coliform counts can identify inputs of untreated sewage, although contamination from wildlife and livestock may also affect bacterial counts (Dudley and Karr 1979). Finally, many existing biological indexes may only apply to a narrow geographical area (e.g., lake trout stocks in Laurentian Great Lakes).…”

Land Application of Sugar Beet By‐products: Effects on Runoff and Percolating Water Quality

“…High levels of BOD in streams deplete dissolved oxygen in the water. If the dissolved oxygen drops below a critical level of 0.75 to 2 mg L −1 (depending on the water temperature), fish, zooplankton, and other aquatic life die (Dudley and Karr, 1979; McCahon et al, 1991; Hall and Schreier, 1996).…”