|Lerch, Robert - Bob|
Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 2/3/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Urbanization and agricultural activities pose potential water quality threats to the Devil's Icebox cave and its ecosystem. Water quality samples were collected in the cave (located in Rock Bridge Memorial State Park, south of Columbia, MO) on January 17, 1998 at several locations along the main cave stream and at all major tributaries. The primary objective of the water quality sampling was to characterize the current water quality status of the cave with an emphasis on contaminant transport of nutrients, herbicides, and bacteria. Herbicide contamination was restricted to the main cave stream with levels consistently near 0.3 ppb (ug L-1) for atrazine, 0.2 ppb for DEA, and 0.06 ppb for metolachlor. Although the herbicide levels were well below drinking water standards, these levels are significant given that winter time concentrations of these compounds in surface streams of the region are often considerably lower. Nutrient levels were generally low, but the mean nitrate-N (NO3-N) concentration of 2.1 ppm (mg/L) suggested an impact of human activities. Coliform bacteria (total coliforms, including free-living and fecal coliforms) were found at significant densities in every water sample tested. At the 2210L site, total coliform concentrations were four times greater than the highest level observed in an earlier study conducted from 1982-84. Based on the seasonal fluctuations observed in the previous study, we predict current peak spring/summer levels at perhaps 80 to 300 times those seen 16 years ago. The observed contaminant levels indicate that human activities are significantly impacting the water quality within the Devil's Icebox drainage basin.