Water Well Journal

November 2016

Water Well Journal

Issue link: http://read.dmtmag.com/i/740475

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Page 22 of 90

Best Suggested Practices Must Be Followed in Areas Impacted by Flooding Due to the extreme flooding tak- ing place in areas around the nation, NGWA is offering best suggested practices for when contractors may be called upon to service household water well systems in areas impacted by flooding. NGWA's best suggested practice Residential Water Well Disinfection Following a Flood Event: Proce- dures for Water Well System Profes- sionals states disinfection procedures should be tailored to each well's dimensions, design, and conditions—but provides general requirements of emergency disinfection in response to floodwaters. Contractors should instruct well owners to immediately find alternative water sources and stay away from the well pump to avoid electric shock. To view the four-step process NGWA recommends well owners follow after flood events, visit www.ngwa.org/Media-Center/press/2016/Pages/2016- 09-29-flooding.aspx. On site, contractors need to evaluate the well system as one of two classifications: (1) wells that are not generally at risk based on their construction and maintenance, and (2) wells that are at risk due to construction deficiencies or lack of maintenance that comprises the integrity of the well. Steps involved in well disinfection, as outlined in the BSP, include: • Inspection of the flooded well for the presence of organic matter • Well flushing and/or cleaning • Proper mix, contact time, and distribution of well disinfection agents • Water testing intervals. The Well Disinfection Following a Flood BSP was devel- oped by a work group of NGWA member professionals draw- ing from extensive work experience and referenced research. It is available for free online in the NGWA Bookstore. International Webinar Series Details Management and Sustainability of Groundwater Resources A webinar focusing on groundwater issues in Chile will take place on November 9. The webinar is part of NGWA's international brown bag se- ries, designed to discuss groundwater research and education for the long-term management and sustainability of ground- water resources on a global scale. The webinars are free to NGWA members as a benefit of their membership. Groundwater issues in China, Australia, and Haiti were covered in NGWA webinars in recent months. NGWA will The LOG waterwelljournal.com 18 November 2016 WWJ Blistering speed. 70% less mess. Unique capabilities not found anywhere else. Picture a sonic drill in your future! SONIC DRILL CORPORATION Suite 190#120, 119 N. Commercial St., Bellingham, WA 98225 1-604-588-6081 www.sonic-drill.com Award-Winning Patented Technology Award-Winning Patented Technology Introduction As a service to members of the National Ground Water Association, this document provides the water well system professional (WWSP) with basic knowledge and suggested practices on this subject. Because of varying geologic conditions and other factors, it is not practical to develop a totally prescriptive guideline and this document is not a substitute for independent professional judgment by a WWSP. There are references throughout this document to public health standards in the United States; other nations may have different standards. Recommended procedures are always subject to review and revision by local or state regulation and advisories by local or state authorities. This document provides best suggested practices (BSPs) for emergency water well disinfection following inundation from a flooding event for residential wells. While disinfection procedures should be tailored to each well's dimensions, design, and conditions, the following recommenda- tions are general requirements of emergency disinfection in response to inundation from flood- waters. Such decisions are site-specific and, thus, should be based on careful analysis by the WWSP. Subsequent positive coliform test results may require thorough cleaning of the well by the WWSP with removal of the pump including brushing and airlifting of debris from the very bottom of the well. After the residential water well has experienced a flood event, the residents shall boil their water or use an alternate clean water supply until a WWSP has completed inspection and/or disinfection of their well system. All disinfection procedures shall be performed by a WWSP. • Section 1 provides general recommendations for emergency well disinfection of a drilled water well. • Section 2 provides specific steps for disinfection, dependent on well configuration. • Section 3 discusses proper disinfection follow-up procedures. 1/16/2013 Residential Water Well Disinfection Following a Flood Event: Procedures for Water Well System Professionals NGWA Best Suggested Practice Approved by NGWA Board of Directors:

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