Quick Answer:
If you see sand, dirt, or dark particles after your water service was turned off or back on at the curb, it is usually loose material from the street-side pipe or from internal pipe corrosion that was disturbed when the curb stop was operated. Stop using affected fixtures, check with your water utility about when the curb stop was operated, and follow a careful flushing routine before assuming there is a larger contamination issue.
Why This Happens
When a curb stop is closed or reopened, the change in flow can dislodge small deposits that have collected in the service line, in the water main near the connection, or inside older household pipes. If the utility performed maintenance, they may have introduced a surge or debris into the line. Common sources are mineral scale, rust flakes, or grit carried in from an outdoor connection. You might notice grit at outdoor taps or dark flakes in indoor fixtures.
If you want to read more about similar appearances, see Grit from outdoor spigot for outdoor tap cases and Black particles in sink water for dark particles that show up indoors.
Step-by-Step What to Do
Step 1 — Pause and check with the utility
- Call your water utility or check their outage/maintenance notice. Confirm the exact timing of any curb stop operation in your area. The utility can tell you whether they did work that might have caused the sediment.
- Ask if they performed any planned flushing or had an unplanned event that could introduce debris.
Step 2 — Avoid immediate use of hot fixtures
- Use only cold water from a tap until you flush lines. Hot water heaters can draw sediments into the tank and make removal harder.
Step 3 — Flush your lines systematically
- Open an outside faucet or the lowest cold-water tap in the house for several minutes to clear the service line into an appropriate drain or outdoors.
- Then open an upstairs cold tap to allow fresh water to flow through your home piping. Do this one tap at a time for a few minutes each until the water runs clear.
Step 4 — Check individual fixtures
- Inspect aerators and showerheads for trapped particles and clean them if needed.
- If a single fixture still shows sediment after flushing, remove and check the fixture parts for debris or corrosion.
Step 5 — Document and report persistent problems
- If sediment doesn’t clear, take photos, note the time you first noticed it, and report back to the utility. They may collect samples or schedule further investigation.
What Not to Do
- Do not operate curb stop yourself to clear sediment. That valve is not intended for homeowner use and can damage the service or cause pressure problems.
- Do not run chemical cleaners into the water system to try to remove particles.
- Do not ignore discolored or gritty water if it persists for more than a short flushing period; it could indicate plumbing damage or an ongoing source of contamination.
When to Call a Professional
- Call the water utility immediately if you suspect the problem is coming from the street main or if multiple homes are affected.
- Contact a licensed plumber if sediment continues after thorough flushing, if fixtures are clogged or damaged, or if you discover corrosion inside household piping.
- If water has a strong odor, color that does not clear, or you notice staining on clothing or fixtures, get professional help before using water for drinking or cooking.
Safety Notes
- Avoid drinking or cooking with water that is visibly contaminated until it clears and the utility or a plumber confirms it is safe.
- If you collect a water sample for the utility, use a clean container and label it with the date and location tapped.
- Wear gloves when handling rusty or gritty debris to avoid skin irritation and wash hands afterward.
Common Homeowner Questions
- Will the sediment harm my plumbing? Usually small particles do not cause immediate damage, but persistent sediment can abrade fixtures and fill aerators or screens over time.
- How long should flushing take? Typically a few minutes per tap; larger or older systems may need longer—up to 15–20 minutes at some outlets.
- Who is responsible for cleanup? The water utility is responsible for the public main and curb stop area; household plumbing beyond the shutoff is the homeowner’s responsibility unless the utility caused damage during work.
For more related articles, see the Black Specks, Sediment, or Grit in Water hub.