An official website of the United States government.
The long term goals of this project are to identify and quantify dairy farm pathogens (Escherichia coli and Cryptosporidium parvum) in barnyard and milking operations wastewater, feed bunks and farm ditch runoff generated during summer and winter precipitation, and to assess a novel steel slag filter technology for reducing these organisms from dairy farm effluents in cold northern climates. We aim to i) identify Escherichia coli (E. coli) and Cryptosporidium parvum (C. parvum) occurrence in point and non-point pollution sources at the University of Vermont (UVM) dairy farm; ii) to evaluate the effectiveness of the electric arc furnace (EAF) steel slag filter technology in reducing these pathogens from point (barnyard and milk house operations effluent) and non-point (Cross Winds dairy farm ditch, Grand Isles, VT) pollution sources; iii) to determine the fate of E. coli and C. parvum in EAF steel slag filters; iv) to assess the impact of water quality parameters, in particular phosphorus (P), total suspended solids (TSS), and organic matter (BOD5) concentrations, on E. coli and C. parvum occurrence, transport and survival rates in dairy farm effluents and runoff.
NON-TECHNICAL SUMMARY: Dairy farm point and non-point pollution sources can contain water borne pathogens (fecal bacteria and zoonotic pathogens) and therefore represent a growing public health risk. The purpose of this research is to quantify dairy farm pathogens Escherichia coli (E. coli) and Cryptosporidium parvum (C. parvum) in barnyard and milking operations wastewater and in feed bunk and farm ditch runoff generated during precipitation events, and to assess a novel steel slag filter technology for reducing these organisms from point and non-point dairy farm effluents in a cold northern climate. In addition, the effects of water quality parameters, such as phosphorus, suspended solids, and organic matter concentrations, on E. coli and C. parvum occurrence, transport and survival rates in dairy farm effluents and runoff will be evaluated. The objectives will be achieved by long-term monitoring (24 months) of E. coli and C. parvum occurrence in pollution sources and pathways, and after steel slag filter treatment, on two dairy farms in Vermont. Knowledge of the E.coli and C. parvum occurrence and transport, and in particular, the effects of water quality parameters on their fate and quantity in dairy farm point and non-point pollution sources, will significantly contribute to efforts aimed at controlling and eliminating these pathogens. The project will also test the efficacy of EAF steel slag filters as a practical and cost effective technology for pathogen reduction with potential for implementation in water quality policy practices.<P>
APPROACH: 1. Escherichia coli and Cryptosporidium occurrence, transport, reduction and fate in point and non-point pollution sources Water samples will be collected once per week. In addition, samples of freed bunk runoff generated during storm and snowmelt events will be collected from three sites (in 6 replicates). Based on Vermont climate records, we anticipate 25 storm events per year that will generate runoff, with each storm generating 18 samples (east side up and down, and Potash brook). E.coli bacteria will be determined by membrane filtration and on agar as outlined in EPA method 1604 [51]. C. parvum parasites will be determined by fluorescence microscopic analysis after filtering and centrifuging, according to the EPA Method 1623 [52]. Organic matter (BOD5), total suspended solids, Dissolved Reactive Phosphorus (DRP), total Phosphorus (TP) and pH will be determined according to standard methods for the examination of water and wastewater [53]. Statistical analyses employing a repeated measures test [54] will be carried throughout 24 month period of investigation in order to determine: i) differences in the quantities of E.coli and C. parvum in each water sample over time; ii) differences in BOD5, TSS, DRP, TP concentrations and pH values of the various waste streams; iii) the effects of water quality parameters on the E.coli and C. parvum quantities found in each waste stream; iv) the effects of seasonal variations in the occurrence and distribution of E.coli and C. parvum. 2. The effectiveness of the EAF steel slag filter technology in Escherichia coli and Cryptosporidium reduction from point and non-point pollution sources. 2.1. Filter influent and effluent samples will be collected once per week E.coli and C. parvum identification and quantitative analyses and BOD5, TSS, DRP, TP and pH will be determined as described in the previous section. The effectiveness of the EAF steel slag filters will be calculated as a percentage reduction in the quantities of E.coli and C. parvum found in the influent and effluent samples. In addition, the performance and longevity of the EAF steel slag filters in terms of the effects of biofilm development and clogging on the E.coli and C. parvum reduction, will be also investigated. 2.2. Non point source pollution monitoring at the Cross Winds Dairy: Grab samples will be collected from 2 points once a week, for E.coli and C. parvum quantitative analyses and water quality parameters determination, including TSS, DRP, TP and pH. In addition, water samples will be collected during rain events of 0.05 inches and above upstream and downstream from the steel slag filter, in 6 replicates. For each storm event we will measure runoff volume, enumerate the pathogen loads, and record a site-specific conditions (precipitation, channel water depth, water quality parameters), creating a data set for statistical modeling of the retention efficiency of EAF steel slag filters for waterborne pathogens E.coli and C. parvum.