Demonstration of Ice Pigging Technology to Remove Biofilms in Water Distribution Systems
Abstract
Excessive buildup of biofilm and sediment in Department of Defense (DoD) water distribution systems can lead to loss of residual disinfectant as well as generation of elevated levels of disinfection byproducts such as nitrite/nitrate and trihalomethanes (THMs), which could trigger SafeDrinking Water Act (SDWA) violations. Common solution is implementation of extensive hydrant flushing programs to discard water that no longer has adequate residual disinfectant, and continue flushing until adequate residual is restored. This project demonstrates removal of biofilms and sediment buildup in drinking water distribution systems at Naval Air Station Lemoore, California, using a new water main cleaning technology known as ice pigging. Effective removal of biofilms could reduce the need for water system flushing, resulting in significant water saving. Ice pigging uses an ice and water slurry that is introduced into the water mains, and gets propelled through pipes using the distribution systems own pressure to achieve cleaning and removal of loose materials on pipe walls with minimal impact on water system operation. The ice plug forms a compact durable mass to scrape pipe surfaces without the risk of permanently blocking choke points in the system. Unlike the conventional pig, the ice-water slurry is able to maneuver itself through pipes having different sizes, bends, valves, and fittings without risking system blockage or damages. The ice pigging waste is collected through downstream hydrants for disposal. Project team demonstrated the ice pigging technology at Naval Air Station Lemoore, California in May 2016. The demonstration cleaned 55,845 feet of pipes having diameters ranging from 6 to 16 inches. To evaluate the technologys performance, benefits, and costs, the project monitors hydrant flushing frequency and volumes, and system water quality, including bacterial analysis for pre- and post-pigging to validateimprovement in system operations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 27, 2019
- Accession Number
- AD1070998
Entities
People
- Alex Mathews
- Dawn Halpern
- Paul Treloar
- Steve Fann
Organizations
- Naval Facilities Engineering Systems Command