Sanitary sewer overflow: Difference between revisions

Revision as of 23:16, 8 May 2023

Revision as of 04:01, 8 January 2024

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===Blockages===

Decentralized failures in dry weather mainly occur from collection sewer line blockages, which can arise from a [[debris]] clog or tree root intrusion into the line itself. Approximately half of SSOs in the United States are caused by blockage.<ref name="EPA-RTC"/>{{rp|p. 4–26}} [[Brown grease|Grease]] is the blocking agent in approximately half of U.S. SSOs attributed to blockage, and solid debris is the blocking agent for another 25 percent. [[Root]]s are a contributing factor in approximately one-quarter of United States SSOs attributed to blockage. Grease deposits are caused by cooking fats liquified with hot water for discharge to sanitary sewers. These fats congeal as solid deposits in the cooler sewer. Solid debris includes soiled clothing, [[diaper]]s, and [[sanitary napkin]]s flushed down the toilet rather than being put in a waste bin.<ref name="EPA-RTC"/>{{rp|p. 4–28}}

Many U.S. municipalities require restaurants and food processing businesses to use [[grease interceptor]]s and regulate the disposal of fats, oil and grease in the sewer system.<ref>For example, the [[Washington Suburban Sanitary Commission]] (WSSC) in Maryland, U.S.: {{cite web |title=Fats, Oils, & Grease |url=https://www.wsscwater.com/fog |website=Special Wastewater Discharge Requirements |date=2023-12-29 |publisher=WSSC |___location=Laurel, MD}}</ref>

One of the main problems of a decentralized line failure is the difficulty of defining the ___location of overflow, since a typical urban system contains thousands of miles of collection pipes, and the central treatment plant has no way of communicating with all the lines, unless expensive monitoring equipment has been installed. Companies in the UK have widely deployed bulk dielectric [[transducer]]s suspended in the sewers to detect high levels and to report the events back over fixed wireless data networks. In certain locations this practice has permitted the reduction of pollution events by up to 60 percent.{{citation needed|date=June 2016}}