ESTCP has recently funded Naval Facilities Engineering Command Southwest (NAVFAC SW) to demonstrate the ice pigging technology at Naval Air Station Lemoore, California. This technology is expected to reduce water consumption needed to maintain and improve water distribution systems.
Hydrant flushing is typically used to remove excess biofilm, sediment, and build-up of disinfectant byproducts in DoD and commercial water distribution systems. Failure to flush these systems frequently can lead to potential Safe Drinking Water Act (SDWA) violations. Water pressure required by firefighting units is of particular concern as well, so systems are flushed to avoid diminished performance. Though this method is effective and widely used due to the low cost, it is extremely water intensive. In a time of increasing water scarcity, especially in California and the southwestern United States in general, there is a disconnect between the performance and safety concerns and the need for water conservation.
Ice pigging uses significantly less water than traditional flushing methods, and the goal of the ESTCP demonstration is to reduce water consumption by 25%, which is the current target for mandatory water restrictions recently issued by the state of California. The technology utilizes an ice slurry that is pushed through the water distribution system by the system’s own pressure. An ice plug forms a compact mass that conforms to the shape of the pipe and uses friction from the ice to clear the pipe. The technology has been tested and is safe to run through different size pipes, valves, bends, or other fittings, unlike traditional pipeline cleaning pigs. In addition to the primary objective to reduce water consumption, the ice pigging technology has the potential to reduce the need for chemical disinfectants such as chlorine, due to a reduction in biofilms and other organic build up.
Originally developed in the United Kingdom by the University of Bristol, the technology has had limited demonstrations to date in the United States. The project is anticipated to conclude in 2017, and will provide a case study with measureable economic and performance results to support broader deployment across DoD.