Quick Answer:
If you see rust-colored water immediately after nearby crews worked on the street, it’s usually sediment stirred up in the public main or a temporary pressure change from hydrant flushing. First call the local water utility to confirm whether they were flushing or doing repairs, then compare the color of the first water you draw from a faucet with the water after running the same faucet for five minutes. That comparison tells you whether the issue is in the public line or inside your home piping.
Why This Happens
City crews opening hydrants, replacing mains, or changing flow patterns can disturb iron and other minerals that normally sit on the inside of pipes. When disturbed, that sediment travels with the water and shows up as brown, red, or orange coloring. Older iron pipes, service lines, and water heaters can also release rust when flow or pressure changes. Usually the problem is temporary, but you need to verify whether the utility work caused it or whether something at the house needs attention.
Step-by-Step What to Do
1. Call the water utility to confirm flushing activity
- Use the utility customer service number and tell them when you noticed the discoloration. Ask whether crews were flushing, repairing mains, or working on hydrants in your area and how long the activity is expected to continue.
- Ask if there are any advisories for your neighborhood and whether they recommend waiting before running taps or installing equipment.
2. Collect the first-draw sample
- Pick a cold-water faucet that hasn’t been used for several hours (overnight is best). Turn it on and note the color immediately—the “first draw.” Take a photo or hold the sample in a clear glass for comparison.
3. Run the same faucet for five minutes and compare
- Keep the same cold-water tap running at a steady flow for five minutes, then observe the water again. If the water clears after five minutes, the sediment was likely in the main or service line and is being flushed out.
- If the water remains cloudy or rusty after five minutes, the issue may be inside your home or with your private service connection.
4. Flush other faucets in a planned order
- Open cold taps starting at the lowest point in the house (basement or ground floor) and work upward. This helps push sediment out of the system without sending it to higher fixtures first.
- Don’t run hot water during this initial cold-water flush; using hot water can draw rust into the water heater.
5. Check hot water and water heater
- If only hot water is brown, the issue may be the water heater’s sediment. See Brown water only when hot water used and Brown water after water heater drain for steps on diagnosing and addressing heater-related rust (do not attempt a heater flush if you are unsure—call a professional).
6. Document and follow up
- Take photos of discolored water, note times, and keep records of your call with the utility. If the utility confirms they finished flushing but discoloration persists, contact them again and consider contacting a licensed plumber.
What Not to Do
- Do not install filters until the utility confirms their line flushing is finished.
- Do not run hot water or start the dishwasher or washing machine while water is visibly discolored—hot water can set stains and draw sediment into the heater.
- Do not assume the discoloration means the water is unsafe without checking; however, avoid drinking if it looks heavy or tastes metallic and contact the utility for guidance.
- Do not attempt invasive repairs (cutting into service lines, altering municipal connections) yourself—leave those to the utility or a licensed plumber.
When to Call a Professional
- Call a licensed plumber if discoloration persists after the utility confirms flushing is complete, or if only your house is affected and steps above don’t clear the water.
- Contact a plumber sooner if you have ongoing low water pressure, visible corrosion at fixtures, or appliances showing signs of rust damage.
- If the water has an unusual taste or odor, or if household members experience health symptoms, follow the utility’s guidance and consider professional testing.
Safety Notes
- Rusty water is usually an aesthetic and staining problem rather than an immediate health hazard, but avoid drinking water that tastes strongly metallic or looks heavily discolored until cleared.
- Avoid using hot water for bathing, cooking, or laundry while water is rusty to prevent staining and to keep sediment out of the water heater.
- If you suspect contamination beyond rust (cloudiness, unusual smell, visible particles other than rust), stop using the water for drinking and cooking and call the utility for guidance.
Common Homeowner Questions
- Will boiling the water remove rust?
Boiling will not remove rust; it may concentrate minerals. Contact the utility if you need a confirmed safe source of drinking water. - Is it safe to drink after the water clears?
If the utility confirms flushing and the water runs clear and odorless, it is typically safe to use for drinking and cooking. - How long should the discoloration last?
Most cases clear within a few hours to a day after flushing stops; if it lasts longer, follow up with the utility or a plumber.
For more related articles, see the Brown or Rust-Colored Water Events hub.