AWWA EDC52040

In the early 1900s, sand-cast iron pipe was used almost exclusively for waterdistribution piping in the City of Edmonton, Alberta, Canada. During a period ofrapid growth following World War II, a significant amount of cast iron pipe wasinstalled, most of which was the spun-cast type. An increasing break frequencyled to the decision to discontinue the use of cast iron pipe in 1965. The breakfrequency continued to increase throughout the 1970s and early 1980s and limitedreplacement of the most problematic sections of cast iron pipe was performed. In1985, a peak of 1,600 water main breaks were recorded on 758 miles of piperesulting in significant inconvenience to many customers. In response to theproblem, a surcharge was introduced to the water bills of all customers in theCity of Edmonton to specifically fund a cast iron water main replacement program.By the end of 1997, the capital program funded through the surcharge had expendedover $70 million which resulted in a decrease in the length of cast iron watermain to approximately 544 miles and a corresponding decrease in the annual numberof breaks to 489. Aqualta, Edmonton's privatized water utility, is now shiftingfrom a reactive to a proactive approach to managing the remaining cast iron pipenetwork. Alternative technologies such as cathodic protection are now beingapplied to some problematic pipe to reduce the rate of deterioration. The utilityis also looking to the use of non-destructive testing for evaluation of pipecondition and artificial intelligence computer models for prediction of failurelikelihood. This paper discusses Aqualta's cast iron water main replacementprogram. Includes reference, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/1999

Number of Pages:

12

File Size:

1 file , 1.2 MB