Reading the Water Meter to Catch a Hidden Leak: Two-Hour Test and Toilet Dye Test

Gwinnett County's water department says leaks account for more than 10,000 gallons of wasted water in an average home every year. Its test rests on one fact: nothing on the meter moves while nobody uses water inside or outside the house.

That makes the meter useful before any stain shows up. A moving dial with a dry ceiling still tells you something is open.

The county asks everyone at home to stay off the sinks, showers and toilets for the length of the test. Irrigation and hoses count too, since the test covers use outside the house.

Leave the washer, dishwasher and ice maker connected, with their supply valves open. They only need to sit idle. The county makes one exception: an appliance that runs without stopping, as some ice makers do, can be closed off at its own supply.

In the county's description, the meter sits in the front yard under a metal cover. Take the cover off to see the dial.

Note the numbers on the readout, or photograph them. Then look at the small leak detection wheel and the needle on the face. Both stay still when no water is in use.

Read the meter again once two hours have gone by with no water used. The readout matches your first number.

A changed number, or any wheel or needle movement during the wait, means a probable leak in the county's words, somewhere in the plumbing past the meter.

Toilets come first, since some leak silently. The county suggests one teaspoon of food coloring in the tank, no flushing, and a 30-minute wait. Color in the bowl confirms it, and a worn rubber flapper is the usual cause. The county also provides dye-tablet kits for this test.

Next, look for dripping faucets and showerheads, then check the pipes under sinks, in the basement and by the water heater. Walk the yard, too. Soggy patches can point to a leak in underground pipes.

If a pipe is gushing, shut it off at the meter. The county describes turning the curb stop clockwise with pliers until the holes match.

Every step above comes from Gwinnett County's pages, so it fits addresses on the county's system. Tucker is a DeKalb County city, and none of the DeKalb pages opened for this site lay out a meter test.

For DeKalb addresses, main breaks and sewage system emergencies go to Watershed Management on 770-270-6243. Check with the utility on your water bill about how its meter works before leaning on this test.