Xylem

With water main breaks increasing, utility customers were experiencing unpredictable service outages, costly repairs, and highly disruptive road closures. To improve its reputation and customer service, the utility wanted to be more proactive in its water infrastructure management and prioritize pipes that needed the greatest attention.

A high-quality water supply is central to the overall health of the agricultural economy, the viability of cities and rural communities, and the environmental well-being of the landscape. Zebra mussels pose a significant threat to the Great Lakes area, negatively impacting the aquatic biodiversity of the area and causing serious problems for power plants and industries that rely on the local water supply by rapidly coating water intake pipes with colonies as large as 700,000 mussels per square meter.Mussel infestations have been estimated to cost the power sector in the Great Lakes region several million dollars annually. The most common methods of managing invasions include chemical treatment, such as chlorination, and non-chemical treatment such as ultraviolet light treatment. However, these treatments are not without their own issues. There are concerns that extensive chlorine use in rivers and lakes could be harmful to non-target organisms.The oxidizing properties of chlorine can also corrode metal surfaces, damaging water cooling equipment. For a cogeneration power plant operating in the New York region, this treatment has caused a corrosive attack on the copper tubing of its heat exchanger, which utilized river water to cool oil for a turbine. The corrosive degradation resulted in the leaking of lubricating oil into their water-cooling stream which was subsequently discharged back into the local waterway.The leaking oil was having a resulting effect on the whole ecosystem, endangering native species, threatening supplies of clean drinking water, and polluting irrigation efforts. The region is known for its bountiful and diverse agricultural production, occupying over a third of the land area of the Basin, and supporting 7 percent of American and nearly 25 percent of Canadian farm production. When polluted water is used to irrigate agricultural lands there is a risk of polluting the food chain that serves so many.The plant still needed to use the river water but had to ensure it wouldn’t damage its equipment in the process. It needed a water-cooling system that could withstand the corrosive, chlorine-treated river water to guarantee continuity of service, avoid costly downtime and protect the local water supply.

In the past, Air Selangor used a variety of techniques to identify leaks and bursts. However, there was still a need for a quicker response to minimize the runtime of leaks/bursts and the disruption caused. Historically, the utility faced a long runtime of leaks before discovery, often due to the remote geographical location of its trunk main network. Furthermore, pressure transients were known to be an issue within the network, but without information on their sources or causes.Air Selangor also noticed that leaks often recurred on the same pipelines, causing concern and harming the utility’s reputation. Air Selangor actively sought innovative ideas for continuous monitoring to identify leaks and pressure surges earlier, reduce NRW and improve customer relations.

LHPWSS constructed the original Lake Huron Primary Transmission Main in 1965. The main is comprised of a prestressed concrete cylinder pipe (PCCP) that is 1200 millimeters (48 in) in diameter.The pipeline experienced failures in 1983 and 1988. Due to these failures, LHPWSS undertook a major capital project to create redundancy along the pipeline by twinning it in three high-pressure areas. Then, in 2010 and 2012, the transmission main failed again in sections that were not twinned.These failures disrupted the supply of drinking water to a significant portion of southwestern Ontario.  The failures also caused serious flooding. Soil erosion and deposition across multiple farms affected approximately 70 hectares (173 ac) of prime agricultural lands.LHPWSS decided to take an innovative, proactive approach to manage risks associated with the Lake Huron Primary Transmission Main.