High water bill? How to find a leak and when to call a plumber
Updated · KeystoneProGuide editorial team
Does a high water bill mean you have a leak?
Not always, but it is the first thing to rule out. The EPA's WaterSense program says the average household's leaks can waste more than 9,300 gallons a year, that nine percent of homes have leaks wasting 50 gallons or more a day, and that fixing the easy ones can cut a water bill by about 10 percent.
How do you check your usage?
Compare it with a benchmark. The EPA suggests looking at a winter month, January or February, when outdoor use is low: if a family of four uses more than 12,000 gallons in a month, there could be serious leaks. The Philadelphia Water Department gives its own yardstick, an average city household using about 154 gallons a day, and says at least a third of that, about $12 on every bill, can be saved by fixing leaks and changing wasteful habits.
How do you test for a leak?
With the meter. The EPA's method:
- Pick a two-hour stretch when no water will be used in the house.
- Read the meter at the start.
- Read it again at the end. If it has changed at all, you probably have a leak.
Then narrow it down. For toilets, put a few drops of food coloring in each tank; color in the bowl after 10 minutes means that toilet leaks, and you should flush straight after so the tank does not stain. For faucets and exposed pipes, look for water on the outside of gaskets and fittings.
Where are household leaks usually found?
Mostly in a few familiar places, by the EPA's account.
| Leak | Water it can waste (EPA) |
|---|---|
| Faucet dripping once a second | More than 3,000 gallons a year |
| Showerhead leaking 10 drips a minute | More than 500 gallons a year |
| Irrigation leak the thickness of a dime | About 6,300 gallons a month |
| Worn toilet flapper | Thousands of gallons a year, silently |
Toilets deserve the first look. The EPA says they are the main source of indoor water use, nearly 30 percent of it, and that most toilet leaks come from old or worn flappers, which it suggests checking periodically and replacing at least every five years. Outdoors, the EPA suggests checking an in-ground irrigation system each spring for frost damage before turning it on, and checking the garden hose where it meets the spigot; a leak there usually needs only a new washer and a tight connection. On a septic system, the EPA adds, a single leaky or running toilet can add as much as 200 gallons a day to the load on the tank.
Which leaks can you fix, and which need a plumber?
The EPA's list of easy fixes covers worn flappers, dripping faucets with worn washers or gaskets, a showerhead that needs a tight connection and pipe tape, and a garden hose that needs a new washer. It sends harder cases elsewhere: for a shower valve that drips when it is off, it suggests an experienced handyperson or a licensed plumber, and when simple fixes fail, it suggests replacing the fixture with a WaterSense labeled model and consulting a plumbing professional for the installation.
If the meter still moves after every fixture checks out, the leak is out of sight, and finding it is a job for a plumber.
What does fixing a leak cost?
Angi's national ranges for 2026 run from $175 to $550 for leaking pipes, $100 to $300 for toilet repair, and $150 to $600 to replace a faucet or fixture. The hidden kinds cost more: $600 to $4,500 for a leak on the main water line, $500 to $4,000 for slab leak work, and $1,000 to $4,000 for a burst pipe.
Who pays for a leak outside the house?
In Philadelphia, usually the owner. The city says owners are responsible for the pipes that bring water from the main into the home, including those under the sidewalk or roadway, that a leaking exterior pipe usually has to be fixed right away, and that the water may be shut off until it is. The Water Department's zero-interest Homeowner Emergency Loan Program covers that repair for eligible owners who have received a defect notice.
Is there help with the bill itself?
In Philadelphia, several programs exist. The Water Department lists payment agreements, assistance programs for households with low income, seniors and those facing a special hardship, and a Conservation Assistance Program in which customers enrolled in its Tiered Assistance Program get an assessment, after which a technician fixes leaks and inefficient fixtures. Elsewhere, ask your water utility what it offers.
What about leak detection devices?
The EPA's WaterSense program has published a guide to leak detection and flow monitoring devices, which it says can identify leaks or alert you to irregular water use and reduce damage.
What you can fix yourself gives step-by-step limits for the small repairs, repair or replace a toilet covers the biggest indoor water user, and plumbers are listed on the plumbers directory page.
Sources
- Fix a Leak Week, U.S. Environmental Protection Agency (WaterSense)
- Residential Toilets, U.S. Environmental Protection Agency (WaterSense)
- Financial Assistance, Philadelphia Water Department
- How Much Does Plumbing Repair Cost? [2026 Data], Angi
- Follow these tips to get ready for pipe repairs, City of Philadelphia, Department of Revenue
- How to Care for Your Septic System, U.S. Environmental Protection Agency
- Basic Information about Lead in Drinking Water, U.S. Environmental Protection Agency