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Fecal coliform
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<h2 id="fecal-bacteria-as-indicator-of-water-quality">Fecal bacteria as indicator of water quality</h2> <h3>Background</h3> <p>In general, increased levels of fecal coliforms provide a warning of failure in <a href="/facts/Water_treatment/nIstBCdG">water treatment</a>, a break in the integrity of the <a href="/facts/Water_supply_network/IXMHuvYQ">distribution system</a>, possible <a href="/facts/Contamination/RC0L7KRy">contamination</a> with pathogens. When levels are high there may be an elevated risk of waterborne <a href="/facts/Gastroenteritis/b2aRA6MD">gastroenteritis</a>. Tests for the bacteria are cheap, reliable and rapid (1-day incubation). </p> <h3>Potential sources of bacteria in water</h3> <p>The presence of fecal coliform in <a href="/facts/Freshwater_ecosystem/G5xqs19j">aquatic environments</a> may indicate that the water has been contaminated with the fecal material of humans or other animals. Fecal coliform bacteria can enter <a href="/facts/River/GxdjEX21">rivers</a> through direct discharge of waste from mammals and birds, from <a href="/facts/Agricultural/TGztqzJs">agricultural</a> and <a href="/facts/Urban_runoff/GEvrwc1f">storm runoff</a>, and from human <a href="/facts/Sewage/aC5N1kls">sewage</a>. However, their presence may also be the result of plant material, and <a href="/facts/Pulp_(paper)/wIlq5nWm">pulp</a> or <a href="/facts/Paper_mill/n8ht8GtE">paper mill</a> <a href="/facts/Effluent/HPS1Akbo">effluent</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> </p> <h4>Human sewage</h4> <p>Failing home <a href="/facts/Septic_system/55CQ0Kb7">septic systems</a> can allow coliforms in the effluent to flow into the <a href="/facts/Water_table/2j0VD0lF">water table</a>, <a href="/facts/Aquifer/UwG6ksdG">aquifers</a>, <a href="/facts/Drainage/thEd3nfB">drainage</a> ditches and nearby <a href="/facts/Surface_water/KQCY5RcY">surface waters</a>. Sewage connections that are connected to <a href="/facts/Storm_drain/a7DSuple">storm drain</a> pipes can also allow human sewage into surface waters. Some older industrial cities, particularly in the Northeast and Midwest of the <a href="/facts/United_States/P0sCdLe5">United States</a>, use a <a href="/facts/Combined_sewer/UUxl1lwB">combined sewer</a> system to handle waste. A combined sewer carries both domestic sewage and stormwater. During high rainfall periods, a combined sewer can become overloaded and overflow to a nearby stream or river, bypassing <a href="/facts/Sewage_treatment/bqLgnLnJ">treatment</a>. </p> <h4>Agriculture</h4> <p>Agricultural practices such as allowing <a href="/facts/Livestock/Quhv6GvP">livestock</a> to graze near water bodies, spreading <a href="/facts/Manure/1C2z9u3l">manure</a> as <a href="/facts/Fertilizer/ysh3r6NJ">fertilizer</a> on fields during wet periods, using sewage sludge <a href="/facts/Biosolids/KJnIs9yM">biosolids</a> and allowing livestock watering in streams can all contribute to fecal coliform contamination. </p> <h3>Problems resulting from fecal contamination of water</h3> <h4>Human health hazards</h4> <p>Large quantities of fecal coliform bacteria in water are not harmful according to some authorities, but may indicate a higher risk of <a href="/facts/Pathogens/axMXtV1M">pathogens</a> being present in the water.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> Some waterborne pathogenic diseases that may coincide with fecal coliform contamination include ear infections, <a href="/facts/Dysentery/l0yfLtg3">dysentery</a>, <a href="/facts/Typhoid_fever/bKPTIYLl">typhoid fever</a>, viral and bacterial gastroenteritis, and <a href="/facts/Hepatitis_A/k0kw8Gq1">hepatitis A</a>. </p> <h4>Effects on the environment</h4> <p>Untreated <a href="/facts/Organic_matter/t17tVCvk">organic matter</a> that contains fecal coliform can be harmful to the environment. <a href="/facts/Aerobic_decomposition/6Bve4pgl">Aerobic decomposition</a> of this material can reduce <a href="/facts/Dissolved_oxygen/UVhwuc26">dissolved oxygen</a> levels if discharged into rivers or waterways. This may reduce the oxygen level enough to kill <a href="/facts/Fish/fln4gH9V">fish</a> and other aquatic life. Reduction of fecal coliform in <a href="/facts/Wastewater/g6Bn8xvT">wastewater</a> may require the use of <a href="/facts/Chlorine/y27UwYBM">chlorine</a> and other <a href="/facts/Disinfectant/33fF2QzG">disinfectant</a> chemicals, or UV disinfection treatment. Such materials may kill the fecal coliform and disease bacteria. They also kill bacteria essential to the proper balance of the aquatic environment, endangering the survival of species dependent on those bacteria. So higher levels of fecal coliform require higher levels of chlorine, threatening those aquatic organisms. </p> <h2 id="removal-and-treatment">Removal and treatment</h2> <p>Fecal coliform, like other bacteria, can usually be inhibited in growth by boiling water, treating with chlorine, or UV disinfection. Washing thoroughly with soap after contact with contaminated water can also help prevent infections. Gloves should always be worn when testing for fecal coliform. Municipalities that maintain a public water supply will typically monitor and treat for fecal coliforms. It can also be removed by iodine. </p> <h2 id="testing">Testing</h2> <h3>Public health risk monitoring</h3> <p>In waters of the U.S., <a href="/facts/Canada/cWWFM8oc">Canada</a> and other countries, <a href="/facts/Water_quality/PcEERmpX">water quality</a> is monitored to protect the health of the general public. Bacteria contamination is one monitored pollutant. In the U.S., fecal coliform testing is one of the nine tests of water quality that form the overall water-quality rating in a process used by U.S. EPA. The fecal coliform assay should only be used to assess the presence of fecal matter in situations where fecal coliforms of non-fecal origin are not commonly encountered.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> EPA has approved a number of different methods to analyze samples for bacteria.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p> <h3>Analysis</h3> <p class="note">Main article: <a href="/facts/Bacteriological_water_analysis/Kk70eIsk">Bacteriological water analysis</a></p> <p>Bacteria reproduce rapidly if conditions are right for growth. Most bacteria grow best in dark, warm, moist environments with food. When grown on solid media, some bacteria form <a href="/facts/Colony_(biology)/b5QfltwY">colonies</a> as they multiply, and they may grow large enough to be seen. By growing and counting colonies of fecal coliform bacteria from a sample of water, the amount of bacteria originally present can be determined. </p><p><a href="/facts/Membrane_filtration/H82dQc58">Membrane filtration</a> is the method of choice for the analysis of fecal coliforms in water. Samples to be tested are passed through a filter of a particular pore size (generally 0.45 <a href="/facts/Micrometre/7eDFxD2L">micrometre</a>). The microorganisms present in the water remain on the filter surface. The filter is placed in a sterile <a href="/facts/Petri_dish/NmTlB7Ed">Petri dish</a> with a selective <a href="/facts/Growth_medium/97IMkpFP">medium</a>; growth of the desired organisms is encouraged, while other non-target organisms are suppressed. Each cell develops into a separate colony, which can be counted directly, and the initial inoculum size can be determined. Typically, sample volumes of 100 ml will be used for water testing and filtered to achieve a final desirable colony density range of 20 to 60 colonies per filter. Contaminated sources may require dilution to achieve a "countable" membrane. The filter is placed on a Petri dish containing M-FC <a href="/facts/Agar/YancWqMm">agar</a> and incubated for 24 hours at 44.5 °C (112.1 degrees F). This elevated temperature heat shocks non-fecal bacteria and suppresses their growth. As the fecal coliform colonies grow, they produce an acid (through fermenting lactose) that reacts with the aniline dye in the agar, thus giving the colonies their blue color. </p><p>Newer methods for coliform detection are based on specific enzyme substrates as indicators of coliforms. These assays use a sugar linked to a dye which, when acted on by the enzyme <a href="/facts/Beta-galactosidase/fgP6xr9n">beta-galactosidase</a>, produces a characteristic color. The enzyme beta-galactosidase is a marker for coliforms generally and may be assayed by hydrolysis of enzyme-specific glycosides such as o-nitrophenyl-beta-D-galactose. Assays typically include a second sugar linked to a different dye, which produces a fluorescent product when acted on by the enzyme beta-glucuronidase. Because <i>E. coli</i> produces both beta-galactosidase and <a href="/facts/Beta-glucuronidase/ctR23pbs">beta-glucuronidase</a>, combining two dyes makes it possible to differentiate and quantify coliforms and E. coli in the same pot. </p><p>More recently, the chemistry behind enzymatic detection compounds has been updated so that the indicating component is redox active, as opposed to the more usual chromogenic format, allowing fecal indicator bacteria such as <i>E. coli</i> and <i>E. faecalis</i> to be detected electrochemically without any sample pre-treatment. Since the colour of the detection compound is of no consequence, this allows detection in deeply coloured matrices.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> </p> <h3>US EPA testing requirements</h3> <p>In 1989, the <a href="/facts/U.S._Environmental_Protection_Agency/ghI985SI">U.S. Environmental Protection Agency</a> (EPA) published its <i>Total Coliform Rule</i> (TCR), which imposed major monitoring changes for <a href="/facts/Public_water_system/abeW9A8b">public water systems</a> nationwide.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> The testing requirements under the 1989 TCR were more thorough than the previous requirements. The number of routine coliform tests was increased, especially for smaller water utilities. The regulation also required automatic repeat testing from all sources that show a total coliform positive (known as triggered source water monitoring). In 2013, EPA revised the TCR,<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> with minor corrections in 2014.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Coliform_bacteria/droKqWrj">Coliform bacteria</a></li> <li><a href="/facts/Coliform_index/gKJ2BpC1">Coliform index</a></li> <li><a href="/facts/Colony-forming_unit/dvywsBBj">Colony-forming unit</a></li> <li><a href="/facts/Indicator_bacteria/5BMUSeCN">Indicator bacteria</a></li></ul> <h2 id="additional-resources">Additional resources</h2> <ul><li>EPA. <a href="http://www.epa.gov/volunteer/stream/vms511.html">"Monitoring and Assessing Water Quality: Fecal Bacteria."</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Doyle, M. P., and M. C. Erickson. 2006. "Closing the door on the fecal coliform assay." Microbe 1:162–163. ISSN 1558-7460. <a href="http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1" target="_blank">http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Water Quality Monitoring – A Practical Guide to the Design and Implementation of Freshwater Quality Studies and Monitoring Programmes Edited by Jamie Bartram and Richard Ballance Published on behalf of United Nations Environment Programme and the World Health Organization. 1996 UNEP/WHO ISBN 0 419 22320 7 (Hbk) 0 419 21730 4 (Pbk) <a href="https://www.who.int/water_sanitation_health/resourcesquality/wqmchap10.pdf" target="_blank">https://www.who.int/water_sanitation_health/resourcesquality/wqmchap10.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Doyle, M. P., and M. C. Erickson. 2006. "Closing the door on the fecal coliform assay." Microbe 1:162–163. ISSN 1558-7460. <a href="http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1" target="_blank">http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Doyle, M. P., and M. C. Erickson. 2006. "Closing the door on the fecal coliform assay." Microbe 1:162–163. ISSN 1558-7460. <a href="http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1" target="_blank">http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Fresno County Department of Public Health. Fresno, CA (2009)."E. coli or Fecal Coliform Bacteria Contamination in Your Water Supply." Archived 2011-07-18 at the Wayback Machine Notice distributed to private well owners. <a href="http://www.co.fresno.ca.us/uploadedFiles/Departments/Public_Health/Divisions/EH/content/Water_Surveillance/content/Fecal_Coliform_Notice_-_Private_Wells.pdf" target="_blank">http://www.co.fresno.ca.us/uploadedFiles/Departments/Public_Health/Divisions/EH/content/Water_Surveillance/content/Fecal_Coliform_Notice_-_Private_Wells.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Doyle, M. P., and M. C. Erickson. 2006. "Closing the door on the fecal coliform assay." Microbe 1:162–163. ISSN 1558-7460. <a href="http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1" target="_blank">http://www.asmscience.org/content/journal/microbe/10.1128/microbe.1.162.1</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>U.S. Environmental Protection Agency (EPA). Washington, DC (2008). "Analytical Methods Approved for Drinking Water Compliance Monitoring under the Total Coliform Rule." June 2008. <a href="http://www.epa.gov/safewater/methods/pdfs/methods/methods_tcr.pdf" target="_blank">http://www.epa.gov/safewater/methods/pdfs/methods/methods_tcr.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Hinks, Jamie; et al. (2016). "Naphthoquinone glycosides for bioelectroanalytical enumeration of the faecal indicator Escherichia coli". Microbial Biotechnology. 9 (6): 746–757. doi:10.1111/1751-7915.12373. PMC 5072191. PMID 27364994. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5072191" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5072191</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>EPA (1989-06-29). "Drinking Water; National Primary Drinking Water Regulations; Total Coliforms (Including Fecal Coliforms and E. Coli)." Final rule. Federal Register, 54 FR 27544 <a href="/wiki/Federal_Register" target="_blank">/wiki/Federal_Register</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>EPA (2013-02-13). "National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule." 78 FR 10269 <a href="/wiki/Federal_Register" target="_blank">/wiki/Federal_Register</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>EPA (2014-02-26). "National Primary Drinking Water Regulations: Minor Corrections to the Revisions to the Total Coliform Rule." 79 FR 10665 <a href="/wiki/Federal_Register" target="_blank">/wiki/Federal_Register</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> </ol>