[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-565699-105":59,"doc-detail-565699-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","groundwater-bacteria-indicators-fact-sheet-regulatory-water-quality-levels","Groundwater Bacteria Indicators Fact Sheet - Regulatory Water Quality Levels","","Groundwater bacteria indicators explain how total coliforms, fecal coliforms, and Escherichia coli function as evidence of microbial contamination in public drinking water. The summary links indicator detection to health risks from water-borne illness and describes regulatory frameworks including the Total Coliform Rule and Ground Water Rule. It also details regulatory concentration thresholds, testing requirements, approved analytical methods, detection limits, limitations, and natural occurrence sources.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/groundwater-bacteria-indicators-fact-sheet-regulatory-water-quality-levels/565699/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/groundwater-bacteria-indicators-fact-sheet-regulatory-water-quality-levels/565699.png","ImageObject",300,407,{"name":92,"@type":93},"Stanford","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-15","2026-10-13",true,{"@type":102,"interactionType":103,"userInteractionCount":8},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why are total coliforms, fecal coliforms, and E. coli used as bacteria indicators?","Question",{"text":112,"@type":113},"They are generally harmless groups by themselves, but their presence indicates that harmful microorganisms may also be present. Fecal coliforms and E. coli are specifically linked to animal or human waste contamination.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What do the regulatory MCL and MCLG limits require for public drinking water?",{"text":117,"@type":113},"Federal MCL thresholds specify monthly sampling conditions for total coliform positivity and require repeat samples when positives occur. The federal MCLG sets a goal of no coliforms in drinking water.",{"name":119,"@type":110,"acceptedAnswer":120},"What analytical methods and limitations affect bacteria testing results?",{"text":121,"@type":113},"Approved EPA approaches include multiple tube fermentation, membrane filtration, and enzyme substrate tests. Results can be affected by interference from background bacteria and by high total dissolved solids, which may cause false positives.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},565699,1792078655,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":8,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":24,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":144},2336477552062,"https://ap-avatar.wpscdn.com/davatar_994ba38a5ba835b3df7d355c54d3ed8d","Groundwater Fact Sheet Bacteria Indicators  \nConstituent of Concern  \nTotal coliforms, fecal coliforms, and Escherichia coli  \nSynonym  \nE. coli, Bacilius coli, Bacterium coli  \nChemical Formula-  \nCAS Number  \nM0015 (Total coliforms) M0012 (Fecal Coliforms) M0011 or 68583-22-2 (E. coli)  \nStoret Number  \n31501-31505 (Total coliforms) 31616 (Fecal coliforms)  \n99906 or 31648 (E. coli)  \nSummary  \nColiforms, a group of common bacteria, are generally harmless to humans. However, the presence of coliforms at any concentration is an indication that some harmful microorganisms may be present. Fecal coliforms such as Escherichia coli, and other types of harmful bacteria are found in animal and human wastes, and when detected they are indicators of water supply contamination. Ingestion of water containing coliform bacteria increases the risk of contracting a water-borne illness.  \nIn 1989, (revised in 2013), the US Environmental Protection Agency ( EPA) established the Total Coliform Rule (TCR) to help reduce pathogens in public drinking water. The TCR established a maximum contaminant level (MCL) based on the presence or absence of total coliforms in public water systems and required public water systems to conduct sanitary surveys. The EPA published the Ground Water Rule (GWR) in 2006, which required groundwater systems that are at risk of fecal contamination to take corrective action to reduce cases of illness and deaths due to microbial pathogens exposure.  \n\n| REGULATORY WATER QUALITY LEVELS1\u003Cbr>BACTERIA INDICATORS |  |  |  |\n| --- | --- | --- | --- |\n| Type | Agency | Concentration |  |\n| Federal MCL3 | EPA2 | 5.0% of all samples taken in a month is total coliform positive (TC+) |  |\n| State MCL | SWRCB4 | > 40 samples per month | 5% of samples are TC+ |\n|  |  | \u003C 40 samples per month | 1 sample is TC+ |\n|  |  | all systems | any repeat sample is fecal coliform positive (FC+) or E. coli positive (EC+), or when any repeat sample following a FC+ or EC+ routine sample is TC+ |\n| Federal MCLG5 | EPA2 | No coliforms in drinking water |  |\n\n1 These levels are related to public water supplies and do not address domestic wells as they are not under EPA regulation.  \n2 EPA – United States Environmental Protection Agency  \n3 The number of samples collected per month is based on the population served. If a sample is TC+, a set of repeat samples must be collected within 24 hours. If a repeat sample is TC+, the sample will also be analyzed for fecal coliforms or E. coli. The following FC+ or EC+ result is an acute MCL violation, which requires rapid public notification.  \n4 SWRCB-State Water Resources Control Board  \n5 MCLG-Maximum Contaminant Level Goal  \n\n| ANALYTICAL INFORMATION |  |  |\n| --- | --- | --- |\n| Approved EPA methods | 1604 | 600-R-00-013 |\n| Detection Limit | Total coliform and E. coli tests are usually presence/absence only. Most Probable Numbers (MPN) methods may provide a robust estimate based upon statistical derivation. |  |\n| Notes | The EPA has approved several methods to test for the presence of total coliform bacteria. These methods include Multiple Tube Fermentation (MTF), membrane filtration (MF), and enzyme substrate tests. Testing methods for E. coli verification follow these same basic methodologies. Additional tests (not listed below) are available for bacteria (e.g., Enterococci) that are not part of the coliform group and for potentially harmful proterozoa such as Cryptosporidium and Giardia. |  |\n| Known Limitations to Analytical Methods | Interference from heterotrophic (harmless background) bacteria may occur. High total dissolved solids (TDS) may interfere and result in false positives. |  |\n| Public Drinking Water Testing Requirements | Tests for E. coli may be conducted in lieu of fecal coliforms, when allowed. The presence/absence of coliform bacteria is used as a bacteriological indicator for the presence of additional harmful microorganisms. Repeat analyses that test for the presence of fecal colifo","cbCait8wgc0Z9RrN","https://ap.wps.com/l/cbCait8wgc0Z9RrN","pdf",180930,"English","# Constituents of Concern\n## Total coliforms, fecal coliforms, and E. coli\n# Regulatory Water Quality Levels\n## Federal and state MCL, MCLG, and repeat-sampling rules\n# Analytical Information\n## Approved methods, detection limits, and testing requirements\n# Occurrence and History\n## Natural sources and notable outbreak impacts\n# Contaminant Transport Characteristics","[{\"question\":\"Why are total coliforms, fecal coliforms, and E. coli used as bacteria indicators?\",\"answer\":\"They are generally harmless groups by themselves, but their presence indicates that harmful microorganisms may also be present. Fecal coliforms and E. coli are specifically linked to animal or human waste contamination.\"},{\"question\":\"What do the regulatory MCL and MCLG limits require for public drinking water?\",\"answer\":\"Federal MCL thresholds specify monthly sampling conditions for total coliform positivity and require repeat samples when positives occur. The federal MCLG sets a goal of no coliforms in drinking water.\"},{\"question\":\"What analytical methods and limitations affect bacteria testing results?\",\"answer\":\"Approved EPA approaches include multiple tube fermentation, membrane filtration, and enzyme substrate tests. Results can be affected by interference from background bacteria and by high total dissolved solids, which may cause false positives.\"}]","Groundwater Bacteria Indicators Fact Sheet - Regulatory Water Quality Levels | PDF",1791857304,13]