ADMINISTRATIVE REPORT

Date: November 20, 1997

Dept. File No.: 1.40.97.10

CC File No. 5801

TO: Vancouver City Council

FROM: General Manager of Engineering Services

SUBJECT: Water Conservation: Leak Detection Program

RECOMMENDATIONS

A. THAT the proactive leak detection and repair program be adjusted to maintain a proactive hydrant maintenance program, but that City-wide leak detection for mains and services be conducted on a five year cycle, rather than every year, at an annual cost of $40,000.

B. THAT fire hydrant operational training be provided at a cost of $5,000, for all applicable city employees and that current practices that include hydrant inspection be given higher priority. Funding will be provided from the 1998 Leak Detection budget.

COUNCIL POLICY

The City water system operates as a utility, with costs recovered through its water rates. In 1996 Council approved an annual budget of $180,000 for a two year pilot proactive leak detection program. This program assigned a crew and equipment full time, to cover the City to find and repair previously undetected leaks. It was agreed that Engineering Services would report back on the cost versus benefits of this program after completing the pilot.

PURPOSE

This report is an update on the effectiveness of the leak detection program. It gives an overview of the findings of the program and its cost versus benefits.

BACKGROUND

A significant proportion of the water supplied into any municipal distribution system is lost through leakage. According to the National Research Council of Canada, the national average for lost water is 25%. The City of Vancouver does not meter its residential services and so it is not possible to carry out an audit to establish water losses through leakage. A leak detection unit began covering the city in May 1996 to detect and repair leaks and to establish the cost effectiveness of such a program.

DISCUSSION

The proactive leak detection began in May 1996 and had covered the city by February 1997. The program found 4 main leaks, 36 service leaks, 30 valve leaks, and 315 leaking hydrants. We estimate that the savings to the city in this first year were in the region of $300,000, however over 70% of this savings was attributed to leaking fire hydrants. In the seven months worked in 1997 (allowing for work stoppage) our estimated savings were $27,000, again over 70% from leaking hydrants. It was anticipated that there would be a reduction in leaks found in the second year, as most of the existing leaks would have been found in the first year. The results seem to bear this out and the cost effectiveness of a continued annual program is in question. However, new leaks will continue to develop so it is recommended that the program continue at a reduced rate.

The City’s hydrants are being used by a variety of parties, such as the movie industry, contractors, and city crews. When the hydrant is used legally, a permit is issued and a check is carried out, by the City, to make sure the hydrant has been properly closed off after use. However, many people use hydrants illegally and they are often left leaking. Shutting off a hydrant does require some knowledge of its workings; it requires the valve to be shut off completely as it will continue to drain into the ground even though the water from the hydrant outlet has ceased to flow. Although it is very difficult to control illegal use of hydrants, we feel it is appropriate to educate our own staff on the proper techniques of hydrant use. We propose a hydrant operators course for all those involved in hydrant use, at an estimated cost of $5000, funded from the 1998 leak detection budget.

The leak detection project found the vast majority of leaks on hydrants, and this was important information. We intend to use existing programs - the valve inspection and the hydrant maintenance program - to focus on hydrant inspection. This, combined with our proposed five year program, and follow-up inspections from hydrant use permits, will ensure that all hydrants are inspected roughly twice a year.

CONCLUSION

Our leak detection program has been very effective in its first year and the savings in water have been substantial. In the second year, leaks found were seen to decrease noticeably, presumably, due to the fact that most leaks were found in the first year. Leak detection should be carried out, certainly from a water conservation point of view, but its effectiveness on an annual basis is questionable for Vancouver’s system. We recommend a proactive leak detection program be carried out, that will cover the City every five years.

The water loss from fire hydrants is substantial, accounting for over 70% of water lost. Hydrants are being used on a regular basis and will continue to be a leakage problem. We recommend continuing hydrant inspection, by using existing programs and continued proactive leak detection. Training for staff on hydrant operation will also have an impact on hydrant leaks.

Although it is not possible to find all leaks with current detection methods, these results suggest that Vancouver’s water system is in better condition than the NRC’s national average, and that our leakage rate is probably less than 10%.

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(c) 1997 City of Vancouver