Thursday, January 28, 2010

Excuse me, but I have to take another leak check

By Jason Dailey, Director, Public Works

In 2008, Cranberry bought 897 million gallons of water from the West View Water Authority. That same year, we sold 757 million gallons to Cranberry’s water customers. So what happened to the 140 million gallon difference between them? That’s what we’re trying to figure out.

Part of it is legitimate: flushing out the water lines, fighting fires, and system maintenance for example. Altogether, they represent maybe 8 or 10 million gallons.

Another part, we know, is from malfunctioning meters, particularly the large commercial kind that handle tens of thousands of gallons a day. If they’re out of calibration – which can happen over time – it can mean a lot of water isn’t being accounted for. So we have a program to test a third of the commercial meters every year and replace them if they need it. We’ve been doing that for some time now, and it’s saved the Township a lot of money.

But perhaps the most significant, and most easily remedied sources of water loss are leaks from underground pipes in the distribution system. A hole just 1/8 inch in diameter can result in 3,288 gallons of water lost every day – or about 1.2 million gallons a year. That’s over $6,500 at current rates – money that all the other ratepayers are having to make up for in their water bills. So we’re working hard to hold down those loses, which we estimate to represent about nine percent of all the water we buy. That sounds like a lot, and it is, although it’s only about half the average for water suppliers and way less than some of our older communities around Pittsburgh which lose as much as half their water through leaky pipes.

So here’s what we’re doing about it: for some time now, we’ve had a contractor come in and use a sophisticated listening device to pinpoint leaks all along the 170 miles of pipeline in our system. And every year he’s discovered leaks that amount to hundreds of thousands of dollars in lost water. As a result, we’ve decided to have him come in and do his inspection twice a year. That means a leak which develops won’t have to wait another whole year before it’s discovered and repaired.

We think that second inspection will pay for itself many times over, saving our water customers a lot of unnecessary expense.