When water trouble shows up in a St. Louis home, the first question is often who needs to act. A leak near the street, a drop in pressure, or a frozen line can each have a different owner. Before you plan a water treatment project, it helps to sort out which pipes belong to the water provider and which belong to you. Your local rules and your provider's policies decide the exact boundary, so treat what follows as a checklist for finding the answer for your address, not as a final answer on its own.
Start at the meter
The water meter is the usual reference point. In many homes it sits in a box near the street, in a basement, or in a utility room near the front wall. The line from the street up to the meter is the service line, and on many systems the provider maintains that section up to the meter. Plumbing that runs from the meter into the house is commonly the homeowner's responsibility. Confirm this with your provider, because some systems place the boundary at a different point, and older properties may have arrangements that differ from newer ones.
Find both shutoff points
Most homes have two shutoffs that matter. The curb valve, sometimes called a curb stop, sits in the ground near the property line, and it is normally handled by the provider. The main shutoff inside the house is the valve you control, usually near where the water line enters the home, in a basement, crawlspace, or utility area. Knowing both helps you isolate a leak or stop water to the house without guessing. Do not operate the curb valve yourself unless your provider has told you it is safe for you to do so.
Write down what you find
- Locate the meter and take a photo showing its position relative to the front wall or driveway.
- Find the main shutoff inside the house and mark it with a tag.
- Note the location of any cleanouts, the water heater shutoff, and the point where the line feeds your kitchen.
- Ask your provider for a service line map or written confirmation of the ownership boundary.
- Keep these notes with your home papers so the next person in the house can find them.
Why the boundary matters for treatment projects
If you plan to add an under-sink reverse osmosis unit, its feed line usually comes off the cold water supply inside the house, which means it sits on your side of the boundary. That gives you control over the connection, but it also makes you responsible for the plumbing work and the materials. Before any cutting or new fittings, confirm where the main shutoff is and that it closes fully. If you cannot shut the house off with confidence, stop and get help first. Your local building department can also tell you whether a permit applies to the work.
When to call the provider and when to call a plumber
- Call your water provider for problems at the meter, the curb valve, or the service line up to the meter.
- Call a licensed plumber for leaks, freezing, or repairs on pipes after the meter.
- If you see water pooling near an electrical panel or cannot find a valve, shut off what you can reach and call for help right away.
Questions to ask when you call
When you call, ask where your provider's responsibility ends, whether you are allowed to operate the curb valve, and whether any of your lines run through a crawlspace or basement that gets cold during St. Louis winters. Ask whether a repair near the property line is handled by the provider or billed separately. Write down the name of the person you spoke with and the date, since those notes will be useful if the problem returns.
A simple yearly habit
Check your shutoffs once a year, ideally before the coldest weeks of the season. Operate the main valve gently to confirm it moves, then return it to the open position. If it is stiff, leaks at the stem, or will not close, plan a replacement with a plumber rather than forcing it. Keep the meter area clear of debris and snow so it can be read and reached when you need it.