Source: UNIVERSITY OF VERMONT submitted to
ESCHERICHIA COLI AND CRYPTOSPORIDIUM OCCURRENCE, TRANSPORT, FATE AND REDUCTION FROM DAIRY FARM POINT AND NON POINT POLLUTION SOURCES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
NRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
0214414
Grant No.
2008-35102-19222
Cumulative Award Amt.
$96,494.00
Proposal No.
2008-01733
Multistate No.
(N/A)
Project Start Date
Sep 1, 2008
Project End Date
Aug 31, 2010
Grant Year
2008
Program Code
[26.0]- Water and Watersheds
Recipient Organization
UNIVERSITY OF VERMONT
(N/A)
BURLINGTON,VT 05405
Performing Department
PLANT & SOIL SCIENCES
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.
Animal Health Component
35%
Research Effort Categories
Basic
30%
Applied
35%
Developmental
35%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1120210202040%
1330399200030%
4030320110030%
Knowledge Area
403 - Waste Disposal, Recycling, and Reuse; 133 - Pollution Prevention and Mitigation; 112 - Watershed Protection and Management;

Subject Of Investigation
0320 - Watersheds; 0210 - Water resources; 0399 - Watersheds and river basins, general;

Field Of Science
2020 - Engineering; 1100 - Bacteriology; 2000 - Chemistry;
Goals / Objectives
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.
Project Methods
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.

Progress 09/01/08 to 08/31/10

Outputs
OUTPUTS: The main purpose of this project was to investigate E coli and Cryptosporidium occurrence, transport, fate, and reduction from the University of Vermont dairy farm point and non-point pollution sources. Farm wastewater samples were collected monthly at eight sampling points (barnyard settling pit, barnyard manure tank, dairy tank, feed bunk runoff, steel slag filters, constructed wetland effluent, a splitter tank/flume and Potash Brook). Samples of feed bunk runoff generated during storm and snowmelt events were also collected from four sites. All samples contained E. coli, but with counts varying significantly by season. The highest E.coli concentrations were observed in a dairy tank followed by feed bunks runoff and a splitter tank flume. These results provided further evidence that feed bunks runoff can represent a significant source of E.coli contamination. The results from this study also suggest that E.coli is strongly affected by temperature fluctuations as well as farm practices that vary seasonally, such as quantity of germicidal chemicals used during winter and summer. Parasitic coccidians were not detected in any of the wastewater samples. Another facet of this study was the inclusion of laboratory column experiments to investigate the ability of steel slag filtration in reducing E.coli levels from agricultural effluents. Columns filled with slag were used to investigate the effect of different hydraulic residence times on E. coli reduction performance. Remarkable E. coli reduction efficiency was achieved, averaging 92 percent over 450 days. Column experiments confirmed that hydraulic residence time affects the efficiency of E. coli reduction via steel slag filters, with increasing time leading to increased efficiency. Investigations on the ability of steel slag to reduce Cryptosporidium from wastewater using Nosema microspordia showed a decrease in the number of parasites. The investigators emphasize the importance of this finding, as it represents the first demonstration of the ability of steel slag to reduce Cryptosporidium species from wastewater. This work, therefore, confirmed the efficacy of steel slag filters for reduction of E.coli, and, importantly, shows that steel slag can also be efficient in Cryptosporidium reduction. A collateral finding was the discovery of numerous Coleps protozoa on the surfaces of steel slag samples taken from the filter that had been treating dairy effluent. Because these organisms feed on bacteria and other microorganisms, the authors suggest that they may play an important role in regulating E. coli concentrations in steel slag filters. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The major findings and benefits of this project are: 1) feedbunk runoff can represent a significant source of E.coli contamination on farms; 2) E.coli is strongly affected by temperature fluctuations as well as farm practices that vary seasonally, such as quantity of germicidal chemicals used during winter and summer; 3) parasitic coccidians were not detected in any of the wastewater samples; 4) steel slag filtration is very efficient in reducing both E.coli and Cryptosporidium from agricultural wastewater; 5) numerous Coleps protozoa were found on the surfaces of steel slag samples taken from the filter that had been treating dairy effluent for over 500 days. Because these organisms feed on bacteria and other microorganisms, the authors suggest that they may play an important role in regulating E. coli concentrations in steel slag filters; 6) results indicate that livestock farmers could greatly benefit from the use of steel slag filtration to treat silage leachate (feed bunk runoff). With increasingly strict regulations imposed on dairy farmers and agricultural producers and with water quality continually threatened by pollutant loading (from nutrients and pathogens), the potential benefits of adapting steel slag filter technology for silage leachate treatment are extensive.

Publications

  • Bowman, D. and Carleen, E. (2010). Pathogens in Rural and Agricultural Water and Watersheds 2010. State of Knowledge and Future Directions.


Progress 09/01/08 to 08/31/09

Outputs
OUTPUTS: Activities: Farm wastewater samples were collected at the University of Vermont (UVM) dairy farm once per month at four sampling points, in 3 replicates each (barnyard settling pit, barnyard manure tank, dairy settling tank, splitter tank/flume) in order to assess occurrence and transport of Escherichia coli and Cryptosporidium in different sources on the farm. In addition, samples of feed bunk runoff generated during storm and snowmelt events were collected from four sites, including impacted Potash Brook tributary. Samples were split and immediately transported to the UVM Entomology Research Laboratory for E. coli and C. parvum quantitative determination and to the UVM Constructed Wetlands Research Laboratory at department of Plant and Soil Science. At the Entomology laboratory, selective medium (consisting of peptone, lactose, ox-bile dried, brilliant green and agar) was used for detection and enumeration of E. coli. In addition, small scale laboratory column experiments were conducted to investigate adsorption ability of steel slag for microsporidia. After being treated with solution containing sporadious material, steel slag samples were examined under light microscope. Escherichia coli reduction from mixed barnyard and milk parlor effluent via steel slag filtration was monitored at the UVM Constructed Wetlands Research Center demonstration site for additional 350 days, resulting in 500 days of performance monitoring in total. Training: An MSc graduate student from Wageningen University, the Netherlands, was trained for 4 months by the PI, Dr Drizo and senior research technician Mr Eamon Twohig for 4 months at UVM. During his traning, he conducted a small scale experiment consisting of 4 separate columns (volume 1 L each) filled with steel slag material to investigate the effect of different hydraulic residence times (HRT) on Escherichia coli reduction performance. In addition, two undergraduate students were engaged to investigate the effects of pH on E.coli reduction in steel slag filters. Products: As result of the investigations at the UVM dairy farm, a new steel slag filter was developed to test the efficiency of the system to reduce E.coli and phosphorus from subsurface agricultural tile drainage. We are currently working with the Vermont Agency of Natural Resources to install these systems on 2 different farms in St Albans Bay watershed, VT. Dissemination: Results from the project to date were presented on several national and international meetings during 2008-2009 and spurred great interest in steel slag filter systems as potential technology for E.coli reduction. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
All samples collected at the UVM Dairy Farm and analyzed at the UVM Entomology Research Laboratory contained E. coli ranging from 3 x 10e3 to as high as 5.9 x 10e7 per 1ml. Bacteria content revealed significant seasonal variation, suggesting that E.coli is strongly affected by temperature fluctuations as well as farm practices (e.g. differences in the quantities of germicidal chemicals used during winter and summer months). Parasitic coccidian species were not detected in any of the farm wastewater samples, and therefore we concluded that animals at the UVM Paul Miller Dairy Farm are free from coccidian infection. Investigations on the ability of steel slag to reduce Cryptosporidium species from wastewater using Nosema genus microspordia showed that small columns (0.2 and 0.3 m height, containing 0.5 and 0.75 kg steel slag) decreased number of parasites 154 and 818 times, respectively. This finding is extremely important as it represents first investigations on the ability of steel slag to reduce Cryptosporidium species from wastewater. Another important finding was discovery of numerous protozoa from genus Coleps (Ciliatea, Gymnostomatida, Colepidae) on the surfaces of steel slag samples taken from the filter that had been treating dairy effluent for over 800 days. As these protozoa species are known to feed of bacteria and other microorganisms, they may play an important role in regulating number of E. coli in steel slag filters. Two steel slag filters connecting in series, volume of 4 m3 and operating at the hydraulic residence time (HRT) of 6 days each, achieved remarkable E.coli reduction efficiency averaging 92% over a 325 days period. When the efficiency reduced to 40% on day 350, filters were drained and left to rest for a period of 5 weeks. Similarly to phenomena of P rejuvenation observed to occur in slag filters, after 5 weeks of resting, filters regained their full capacity to reduce E.coli, and operated at the average efficiency of 73% for another 100 days. Colum experiment confirmed that efficiency in E.coli reduction via steel slag filters is affected by the HRT. Comparison of slag filters performance at 4, 6, 8 and 12 hours HRT over a period of 60 days showed that E.coli efficiency increased from an average 49 (at 4 h HRT) to 92% (at 12 h HRT). The experiments to date enabled us to confirm steel slag filters efficiency and gain new understanding of the potential reduction mechanisms of E.coli reduction via steel slag filter technology. Perhaps the 3 most important findings in terms of expanding the current knowledge are: 1) the first results demonstrating that steel slag could be efficient in Cryptosporidium species reduction; 2) the discovery of the protozoa species (Coleps) on steel slag surfaces, as future research will be directed towards further understanding of their role in E.coli reduction and 3) the investigation of the impacts of various filter operating HRTs on E.coli reduction performances, which allowed us to further develop steel slag filters for treatment of pollution from diffuse sources.

Publications

  • No publications reported this period