Escherichia coli Contamination of the Dry Creek Watershed

1. Escherichia coli Contamination of the Dry Creek Watershed Geoffrey W. Gearner, Kristen Platt and April D. Haight Morehead State University • Introduction • Fecal contamination (human and animal waste) comes from native wildlife, domesticated animals, and humans. • Sources include straight pipes, inadequate and/or failed household septic systems, and farmland run off of animal waste. • The amount of bacteria that are associated with the feces of mammals, birds, and humans were measured from water samples collected from Dry Creek. • We tested for the presences of Escherichia coli (E. coli bacteria, which is associated with the feces of animals and birds. • Results • Water samples for E. coli analysis were collected periodically from March 2008 through February 2009 at six sites in the Dry Creek watershed. During the spring and summer seasons, five samples were collected over a 30-day period. • For each of the 30-day sampling periods, the geometric means of the five E. coli counts for each site were calculated. Figures 3 and 4 show the geometric means of E. coli counts for selected sites in the Dry Creek Watershed for spring and summer 2008. • No sites exhibit geometric means that exceeded KDOW limits during the Spring 2008 sampling period. However, one site, DC-4.52, had 40% of samples that exceeded the KDOW limit of 240 E. coli/100 mL during that sampling period. Three sites (DC 2.84, DC 1.89, and DC 0.28) exceeded the limit of 130 E. coli/100 mL during the Summer 2008 recreation season, and thus are impaired Discussion The monitoring of fecal-associated bacteria in the Triplett Creek Watershed, including the Dry Creek basin, has been an ongoing project at Morehead State University for the past several years. The data presented in this study shows the continued chronic contamination of the Dry Creek Watershed by E. coli bacteria. MSU researchers are currently working on a project to identify the host sources of E. coli contamination in the Dry Creek Watershed. The Commonwealth of Kentucky has designated Dry Creek as an impaired stream, having been placed on the Second Priority 303b list. Continued bacterial monitoring will assist with the identification of possible sources of fecal contamination. The development of a watershed-based plan will address contamination issues and gauge the effectiveness of remediation efforts. The overall goal of the watershed-based plan is the removal of Dry Creek from the impaired streams list. Figure 1. An example of E. coli bacteria (red colonies) collected from water and grown in the lab on mTEC culture medium. Dry Creek Study Sites Recent Escherichia coli counts in Dry Creek sites, 2008 Figure 2. Map of the bacterial sampling sites in the Dry Creek watershed. Figure 3. Geometric means of E. coli counts in the Dry Creek Watershed, August-September 2008. The red bar indicates the KDOW limit of 130 E. coli/100 mL. Figure 4. Geometric means of E. coli counts in the Dry Creek Watershed, March-April 2008. The red bar indicates the KDOW limit of 130 E. coli/100 mL. This project is funded in part by a grant from the U.S. EnvironmentalProtection Agency under 319(h) of the Clean Water Act through the KentuckyDivision of Water to the Kentucky Waterways Alliance (Grant # C9994861-04) and Morehead State University’s Undergraduate Research Fellowship Program Contacts Tessa Edelen, Watershed Program Director April Haight Kentucky Waterways Alliance MSU’s Center for Environmental Education 222 Bakery Square LC 101A, IRAPP Louisville, KY 40206 Morehead, KY 40351 (502) 589-8008 (606) 783-2455