PROBLEM: NEIGHBOURHOOD LEAD (Pb) HOT SPOT
On-going water quality checks by a major UK water utility identified what is commonly referred to as a "lead hot spot" in a residential estate. The hot spot involved 17 homes running along 2 streets. Water supply to these properties initially ran through a conventional 75mm (3") cast iron main that connected to a shared service lead pipe and lead communication pipes. The lead pipes varied in diameter from about 15mm to 50 mm (½"-2" ID). The shared service line and the communication pipes were 100% lead.
Earlier random daytime testing (RDT) for lead at the customers tap averaged above the 10 µg/l regulatory limit, triggering the requirement to deliver a solution quickly.
The replacement of the approximate 162 metres (530 ft) of the shared service lead trunk line, 17 lead communication pipes and other utility side lead contributors by conventional open cut excavation methods would have resulted in the interruption of parking and access to private properties and closing the street for significant durations, including the intersection with the main feeder road (a bus route). Customer water supply interruptions and the provision for temporary water supplies were also a main consideration. Due to the location and close proximity of other underground services and ground conditions, moling was not a viable option, corroborated by an earlier failed attempt some months prior to replace a single communication pipe using this method.
DECISION: ePIPE® IN-PLACE LINING, DWI/WRAS APPROVED - 2 HOUR CURE TIME AND RETURN TO SERVICE
The Water Company, having successfully worked with Pipe Restoration Services (PRS) on several other lead/leakage remediation projects, decided that the best solution to bring these properties into compliance with new lead regulations was to use the minimally invasive, in-place remediation of the lead pipes using PRS and the ePIPE technology.
Knowing that each lead component in the water supply system contributes to the total count of lead when measured at the kitchen tap (point of compliance), the programme to reduce inline lead contributors included lining the shared lead trunk line, the lead communication pipes and replacement of the boundary boxes with new lead free components. Customer side assets were not a part of this remediation program.
OUTCOMES: ePIPE - LEAD (Pb) HOT SPOT ELIMINATED
Prior to the ePIPE process, lead measured at the customer tap on average exceeded the 10 µg/l cut off limit.
Post ePIPE, RDT testing at the customers tap showed an average 5.11 µg/ of lead, well below the 10 µg/l cut off.
Post ePIPE RDT testing at the boundary box, the limit of lining for this project, showed full compliance with an average result of less than 3µg/l.
Traffic disruption was minimized, there were no road closures and only minimal excavations for access were required.
All customers' water supplies were returned to full service within the notified and scheduled cut off period and there were no restrictions applied in accessing roads, parking or properties during the completion of the works.
Pipe Restoration Services, is an award winning joint venture between UK's Morrison Utility Services and USA's, Pipe Restoration Technologies, LLC. Morrison Utility Services is one of the UK's leading utility service providers. Pipe Restoration Technologies, LLC., (PRT), www.epipeinfo.com focuses on development of product, equipment and process methods used in the business of in-place epoxy pipe lining. PRT services are provided in Europe, US, Canada, and Latin America. PRT holds multiple process patents with an ongoing portfolio of patents pending.
UK ePIPE provider, Pipe Restoration Services (PRS) can be contacted at www.piperestorationservices.co.uk