Maintaining Infrastructure: The Story of a Water Leak
Yesterday (September 15), you may have seen Harrington’s Public Works’ crew working on the shoulder of DuPont Highway in front of Liberty Plaza. They were there to fix a water leak, and it took all day. We are going to use this real world example to better understand both the importance of infrastructure maintenance and the upcoming referendum on water projects.
Repairing the Leak
Public Works employees use a vac truck to remove water from around a pipe in order to repair a line break.
On his way to work, one of the Public Works’ employees noticed a big puddle with running water on the side of DuPont Highway. Alan Moore, Public Works Supervisor, mobilized his workers to fix the problem. First, the leak had to be located with a leak detector. The work area was coned off and one worker assigned to flagging duty as per State of Delaware regulations for state maintained roadways. The crew then chipped away 6” of blacktop, jackhammered through 8” of concrete, and dug out almost 4’ of dirt to expose the troublesome pipe. Multiple holes were found in the uncovered pipe, the biggest of which was about ½” wide. After the valve supplying water to the pipe was turned off, the line was cleaned, and 4 clamps were used to contain the water of the many openings (see the explanation below under Aging Infrastructure as to why the whole visible section of pipe was not replaced). It was then time to backfill the pit with dirt and stone and place a cold patch over the disturbed section of asphalt. Once the materials in the hole have settled, our Public Works staff will return to do a blacktop repair that meets the specifications for State of Delaware roadways.
Costs Add Up
A City worker uses clamps to seal multiple holes in a water line.
The biggest expense was the cost of 5 laborers working on just this project from 7:30 am to 4 pm. In addition to the wear and tear on the equipment used, materials for the repair were approximately $800.
There were 2 businesses (one of which relies on water for its normal operations) and 3 houses that were without water for the day. The Public Works Department also had to suspend its scheduled work for the day to fix the leak.
It is estimated that 30 to 40 gallons of water were lost per minute at our example leak. That is water that has been pumped from the ground and treated to make it drinking water and is now running back into the ground.
This is not the first leak that has occurred in this particular line; there have been 6 incidents of this pipe leaking this year alone. It would make sense to replace the entire length of exposed pipe except that experience has taught the Public Works crew that this leads to return visits to fix even more leaks. This line is old; it was probably placed in the early 1940s, which makes it about 75 years old. It is showing its age. The vibrations from cutting the pipe to replace a section end up causing leaks in other parts of it, so clamps must be used instead.
Proposed Water Projects
The City Council has scheduled a special election to vote on proposed borrowing for water system improvements. One of the projects is upgrading the water line on Liberty Street and connecting the users that are served by our example pipe to the new Liberty Street line. Our 75 year old pipe will finally be retired.
For more information on the proposed water projects, funding, and the special election see the following articles:
Water System Improvements Referendum
Why You Should Vote “FOR THE PROPOSED BORROWING” for the Water System Improvements Referendum
FAQs: Water System Improvements Referendum
If you have any questions, please call City Hall at 398-3530.