[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-510718-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-510718-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","guidance-for-responding-to-water-main-breaks-or-pressure-loss-events","Guidance for Responding to Water Main Breaks or Pressure Loss Events","","Guidance outlines how public water systems should respond to water main breaks and pressure loss events, classifying risks from minimal to highest based on pressure maintenance, localized depressurization, and widespread pressure loss. It specifies actions for pit water control, isolation, documentation of contamination intrusion, disinfection procedures, flushing methods, and when bacteriological sampling and advisories are required. It also addresses chlorine residual monitoring, cross-connection risk in multi-story buildings, planned shutdown notifications, and sample handling with certified lab analysis.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/guidance-for-responding-to-water-main-breaks-or-pressure-loss-events/510718/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/guidance-for-responding-to-water-main-breaks-or-pressure-loss-events/510718.png","ImageObject",300,407,{"name":42,"@type":43},"Franzy","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-22","2026-10-05",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",5,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"How are main break and pressure loss events categorized, and why does it matter?","Question",{"text":63,"@type":64},"Events are grouped from Type 1 (minimal risk) to Type 4 (highest risk) based on whether positive pressure is maintained and the extent of depressurization. The category determines the required sampling, disinfection, flushing, and whether advisories are issued.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"What disinfection and flushing steps are recommended during repairs?",{"text":68,"@type":64},"Guidance includes disinfecting repair parts and exposed pipe, then performing either low velocity flush or scour velocity flush (3 to 7 ft/sec) depending on the event type. It also calls for checking chlorine residual and using shock chlorination or boosting when higher risk applies.",{"name":70,"@type":61,"acceptedAnswer":71},"When are drinking water advisories (BWA, DND, DNU) required?",{"text":72,"@type":64},"A Do Not Drink (DND) public notification and 24-hour bacteriological testing are required for pressure loss events affecting multi-story buildings due to cross-connection susceptibility. For other types, bacteriological sampling and advisories depend on contamination intrusion risk and depressurization extent.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},510718,1791512320,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,100,105,109,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":97,"show_sort_weight":98,"slug":99},"Comic",60,"comic",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},6,"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":107,"slug":108},7,40,"healthcare",{"id":110,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},8,"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":55,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":106,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":26,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":55,"preview_page_count":4},2336478945519,"https://ap-avatar.wpscdn.com/davatar_085a072bc5b1113ac321206ff7593b45","Guidance for Responding to Water Main Breaks or Pressure Loss Events  \nFO R CO MM U N ITY P U B L IC WAT E R SYST E MS  \nTable 1. Event Categories  \n\n| Type 1 | Type 2 | Type 3 | Type 4 |\n| --- | --- | --- | --- |\n| Positive pressure\u003Cbr>maintained during break.\u003Cbr>Positive pressure\u003Cbr>maintained during repair. | Positive pressure maintained during break. Localized depressurization has occurred. | Loss of pressure at break site.\u003Cbr>Localized depressurization has occurred. | Large-scale event. Widespread loss of pressure has occurred. |\n| Maintain pit water below break.\u003Cbr>Repair under pressure. | Controlled shutdown. Notify/provide instructions to affected customers in advance of repair.\u003Cbr>Maintain pit water below break. | Isolate affected area. Document contamination intrusion in the excavation Notify/provide instructions to affected customers. | Isolate affected area. Document contamination intrusion in the excavation Monitor for possible crossconnections and backflow. |\n| No signs of contamination intrusion.\u003Cbr>Disinfect repair parts and exposed pipe.\u003Cbr>Check chlorine residual in distribution system. | No signs of contamination intrusion.\u003Cbr>Disinfect repair parts and exposed pipe.\u003Cbr>Conduct low velocity flush. Check chlorine residual in distribution system. | Disinfect repair parts and exposed pipe.\u003Cbr>Conduct scour velocity flush (3 to 7 ft/sec) .\u003Cbr>Shock chlorinate or boost chlorine residual in distribution system. Instruct customers to flush plumbing upon return to service. | Disinfect repair parts and exposed pipe.\u003Cbr>Conduct scour velocity flush (3 to 7 ft/sec) .\u003Cbr>Shock chlorinate or boost chlorine residual in distribution system. Instruct customers to flush plumbing upon return to service. |\n| No BWA or DND required. No bacteriological samples required. | No BWA or DND required. No bacteriological samples required. | Bacteriological sampling required.\u003Cbr>Based on a thorough field assessment, the affected area may be returned to service and a drinking water advisory may be waived while results are pending.\u003Cbr>Consider depressurization extent and risk of contamination. | Call Duty Officer\u003Cbr>Issue DWA: BWA or DND. Bacteriological sampling required. |\n\nRisk of contamination and intrusion increase with the type of main break or pressure event. Events range from Type 1 (minimal risk) to Type 4 (highest risk) . For systems that continuously chlorinate, they should closely monitor residuals and consider boosting feed rates after higher risk events. For systems that do not normally chlorinate, they may initiate shock or temporary chlorination after consultation with their Minnesota Department of Health (MDH) district engineer.  \nWhen a main break is severe and requires installation of new watermain, all work must follow 2015 Revised AWWA C651-14: “Disinfecting Water Mains.”  \nPressure loss events affecting multi-story buildings are more susceptible to cross-connections, and require a Do Not Drink public notification and 24-hour bacteriological testing of the affected area.  \nFor a planned shutdown of a portion of the distribution system for maintenance or repairs, notify the impacted consumers several days before the event. Instruct consumers to flush service lines and fixtures for five to ten minutes after the event is complete. Collect representative bacteriological samples in the area and have them analyzed at a certified lab. Here is a useful water quality notice for systems to use:  \nImportant Information about Your Drinking Water ([https://www.health.state.mn.us/communiti](https://www.health.state.mn.us/communiti)[es/environment/water/docs/com/templatepn.docx](es/environment/water/docs/com/templatepn.docx))  \nIssuance of a drinking water advisory may be waived if a depressurization event is short term and in an area that has a low risk of contamination. Low risk areas include housing developments, manufactured home parks, or low rise apartment buildings that have no high hazard connections. Instruct consumers to f","cbCaidtwhLT1Y1uD","https://ap.wps.com/l/cbCaidtwhLT1Y1uD","pdf",123845,"English","# Table 1. Event Categories\n## Type 1-4 risk scenarios\n## Recommended response actions\n# Risk considerations and chlorination guidance\n# Regulatory and procedural requirements (AWWA standard, notification)\n# Types of Drinking Water Advisory (DWA)\n## BWA, DND, DNU\n# Definitions and program contact information","[{\"question\":\"How are main break and pressure loss events categorized, and why does it matter?\",\"answer\":\"Events are grouped from Type 1 (minimal risk) to Type 4 (highest risk) based on whether positive pressure is maintained and the extent of depressurization. The category determines the required sampling, disinfection, flushing, and whether advisories are issued.\"},{\"question\":\"What disinfection and flushing steps are recommended during repairs?\",\"answer\":\"Guidance includes disinfecting repair parts and exposed pipe, then performing either low velocity flush or scour velocity flush (3 to 7 ft/sec) depending on the event type. It also calls for checking chlorine residual and using shock chlorination or boosting when higher risk applies.\"},{\"question\":\"When are drinking water advisories (BWA, DND, DNU) required?\",\"answer\":\"A Do Not Drink (DND) public notification and 24-hour bacteriological testing are required for pressure loss events affecting multi-story buildings due to cross-connection susceptibility. For other types, bacteriological sampling and advisories depend on contamination intrusion risk and depressurization extent.\"}]","Guidance for Responding to Water Main Breaks or Pressure Loss Events | PDF",1791244353]