Demonstration of Somatic and F+ Coliphage, E.coli and Enterococci as Indicators of Fecal Contamination in Small Public Water Supplies in Southwestern Montana
Final Report to the Environmental Protection Agency --
March 2006
By Kathleen (Kate) J. Miller and Joseph Meek, both of the Montana Department of
Environmental Quality
Abstract
The principal objective of this research was to demonstrate the appropriateness and effectiveness of using somatic and F+ coliphage, E.coli ,total coliform and enterococci as indicators of fecal contamination of ground water used by small public water supplies in southwestern Montana. A secondary objective was to test for correlations among microbial indicators and ground water contaminants derived from septic leachate, particularly personal care products and commonly prescribed pharmaceuticals.
The Helena Valley, Montana is experiencing marked population growth with attendant proliferation of onsite wastewater disposal (septic tanks and drainfields) systems. Thirty-eight public and private domestic water supplies deriving ground water from the Quaternary/Tertiary valley fill aquifer and various bedrock formations were sampled in the summer and fall of 2005 for pharmaceutically-active compounds, personal care products, and endocrine disrupting compounds (PPCP as used here). The wells were also sampled for microbial indicators of fecal contamination and for inorganic constituents.
The two most frequently detected PPCPs are sulfamethoxazole (SMX) and the herbicide atrazine, with detection frequencies of 80% and 40%, respectively. Atrazine demonstrates a strong correlation with chloride and total dissolved solids (TDS). Because chloride and TDS are commonly used inorganic indicators of water-quality degradation from domestic wastewater discharge, the correlation suggests that atrazine could be occurring in domestic wastewater. This hypothesis should be verified in subsequent investigations.
There is a poor correlation between the microbial indicators of fecal contamination and PPCP occurrence, with zero detections of either E.coli or the somatic or male specific coliphage. Total coliform was detected at only 8 sites. Therefore, the investigators conclude that the potential alternative microbial indicators of sewage pollution do not represent feasible parameters to assess contamination risk to small public water supplies. |
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This is a follow-on investigation of tools previously developed and delivered by the Water Center, to determine the strengths, weaknesses and uses of the interactive, distance-learning approach for the training of small-system operators. The purpose of this survey is to enhance current and future training tools so that water professionals are able to competently operate small public water systems.
Market Research Findings Report -- Communications Audit, E-learning Review, VIP Interview Results, Descriptive Study [7.7MB PDF]
Supplemental Findings Report -- Small Systems Managers and Operators [3.7MB PDF]
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