Infrastructure Replacement: Cast Iron Pipes

One of our projects being undertaken this year is the replacement of cast iron pipes. These aged pipes carrying water and waste water are showing their wear and tear and breaking easily. In Moose Jaw their water main break program has shot up to $2 million per year. In a post last year I showed a picture of a cast iron saddle that our crews dug up.

Cast Iron Pipe, photo from Moose Jaw Times-Herald Lisa Goudy

There is a move to PVC pipe that is expected to reduce breaks. The Town purchases our pipe from Ipex. Bernie, our CAO, has arranged for us and our SK colleagues to have a tour of their facility while we are at FCM in Edmonton in June.

Based on materials installed in 1992-1993 here are some stats regarding the types of pipes installed in municipalities across Canada as research by the National Research Council.

• Cast iron was installed 50% of the time
• Cast iron break rate is 35.9 breaks/100km/year
• Ductile iron pipe is 24% of the system
• Ductile iron pipe break rate is 9.5 breaks/100km/year
• Asbestos-cement pipe is 12% of the network
• Asbestos-cement break rate is 5.8 breaks/100km/year
• PVC is 10 % of the network
• PVC break rate is 0.7 breaks/100km/year

 Here is what ipex has to say about their pipes.

In Canada alone, municipalities lose $650 million in water each year, through broken water mains. At the same time, taxpayers spend roughly $82 million annually to repair these breaks. As North American municipalities continue to replace aging cast iron and asbestos cement pipe with PVC, these expenditures will become largely unnecessary. One survey tracked the performance of cast ductile iron pipe versus PVC in 21 cities over a two-year period. While iron pipe experienced 9.5 breaks per 100 km, PVC had a mere 0.7 failures per 100 km. In municipalities maintaining equal amounts of PVC, cast iron, ductile iron and asbestos cement, PVC pipe accounted for only 1.3% of the repairs. No wonder most of the water distribution pipe currently being installed is PVC. When it comes to installation, PVC pipe offers substantial cost savings over traditional cast iron, ductile iron and asbestos cement piping materials too. Because it weighs less, PVC is less costly to handle. Furthermore, no heavy equipment and fewer tools are required on the construction site.