Quick Answer:
If a leak started immediately after city crews worked on the main, it’s often caused by a loose connection or a valve disturbed during the repair. First close the house shutoff and do a few quick checks: wipe fittings to see where water is coming from, determine whether the leak is at a compression nut or a union, and if the issue is a loose compression nut, try tightening it about a quarter turn. If you see damage, continuing leak after simple tightening, or you’re unsure, call a plumber.
Why This Happens
City crews may briefly shut water off, open or close the meter, or move the meter chain. That can allow fittings that were already marginal to shift, seals to unseat, or a compression nut to loosen. Work on the main can also change the pressure and flow when water is turned back on, which can reveal slow leaks you didn’t notice before.
For related problems that start right after the meter is turned back on, see Water meter leaking after turn-on, and if you noticed weak flow or odd pressure behavior after the work, see City work caused low pressure inside home.
Step-by-Step What to Do
1. Stop the water and make the area safe
- Close the main shutoff inside your home. If that won’t fully stop flow, the meter shutoff might be needed; if you don’t control that, contact the city.
- Turn off electricity to any pumps or water heaters if the leak is pooling near electrical equipment.
2. Dry fittings so you can find the leak
- Use a clean rag or paper towels to dry the meter area, valve body, nuts and unions. Watch closely to see the first point where water reappears — that tells you which part is leaking.
3. Identify compression vs union leak
- Compression fitting leak: you’ll see a nut at the pipe entrance and a small steady drip at or just below that nut. The nut is usually hex-shaped.
- Union leak: unions have a collar that joins two pipe sections and typically rotate; a leak will appear at that collar or the face behind it.
- Knowing which it is tells you whether a nut tightening or reseating the union is the right fix.
4. Try a careful tightening — quarter turn for compression nuts
- If the leak is at a compression nut, use a wrench to tighten the nut about a quarter turn beyond finger-tight. Do this slowly and recheck — over-tightening can damage the ferrule or pipe.
- If the leak is at a union, hand-tighten the union collar, then use a wrench for a light snug — unions usually seal with proper engagement, not heavy force.
- If the leak is from a valve stem (minor drip), a small turn of the packing nut or replacing a worn packing may stop it; if you’re not confident, stop and call a pro.
5. Verify and monitor
- Open water slowly and watch the dried areas. If the leak stops, check again after a few hours. If it persists, do not keep tightening — call a plumber.
What Not to Do
- Do not assume the city will automatically fix any interior leaks you find. Their responsibility usually ends at the meter or property line.
- Do not overtighten nuts or unions; that can crack fittings or distort seals and make the problem worse.
- Do not use quick epoxy or tape as a long-term repair on a pressurized meter connection — these are temporary at best and can hide larger issues.
When to Call a Professional
- Water keeps leaking after you’ve dried and tightened fittings.
- You see damaged threads, a cracked fitting, or the leak is at the meter body itself.
- The leak is large, the main shutoff won’t stop the flow, or water is near electrical panels or appliances.
- You’re not sure whether the problem is on the city side or your side — a plumber can confirm and document the location for you and the city if needed.
Safety Notes
- Always shut off water before loosening any fittings. Work on pressurized pipes can spray water and cause injury or property damage.
- Stand clear of pooled water if electrical equipment is nearby; turn off power if necessary.
- If the area smells of gas for any reason, evacuate and call emergency services — do not work near a potential gas leak.
Common Homeowner Questions
- Why did this start right after the city finished work? — Disturbing the meter or pressure changes when water is turned back on can reveal or loosen weak connections.
- Can I just tighten it myself? — For small compression or union leaks, a careful quarter-turn tightening often helps; stop if it doesn’t work or if you see damage.
- Will the city fix it for me? — Usually they fix up to the meter or property line; interior repairs are normally the homeowner’s responsibility.