Brown water coming out of the faucet

What people usually report

Yellow, orange, reddish, or brown water, sometimes with grit. It may show up after the street has been dug up or a hydrant has been opened, first thing in the morning, at a faucet nobody uses much, or only from the hot tap. Some people notice stains on laundry or fixtures first.

What official sources say the causes can include

• Disturbed water mains. Use of a fire hydrant or a main valve nearby can change the direction or rate of flow, stirring up internal pipe rust and sediment (Seattle Public Utilities).
• Galvanized iron pipe in the building. When the neighbors’ water is clear and yours is not, Seattle says the cause is most likely galvanized iron plumbing, often noticed in the morning, after low use, or at seldom-used faucets. It adds that this does not on its own mean the plumbing needs replacing unless water pressure has also dropped (Seattle Public Utilities).
• Sediment in the water heater. If only the hot water is discolored, flushing the tank may help (Seattle Public Utilities). Cambridge’s water department says iron, magnesium, and calcium sediment can build up in the bottom of a water heater and cause discoloration or rust at hot taps (Cambridge (MA) Water Department).
• Iron or manganese in the water. EPA links rusty color, sediment, and reddish or orange staining to iron above 0.3 mg/L, and black to brown color and black staining to manganese above 0.05 mg/L. These are secondary standards, which EPA does not enforce (U.S. EPA).

What the utility says to do

1. Run the cold water for a few minutes to see whether it clears.
2. If not, let the water sit for 1 to 2 hours, then run cold water in the tub or shower for a few minutes.
3. If it is still discolored, call your water utility.
4. Avoid running hot water while the cold is discolored, so the water heater does not fill with it.
5. If the washing machine is mid-cycle, stop it while it is full and finish once the water is clear, which lowers the chance of permanent stains.

Steps from Seattle Public Utilities. Your utility’s own instructions come first if they differ.

How to find out

Ask a neighbor whether their water is discolored too. Theirs clear and yours brown points inside your home; both brown points to the main. Then:

• On public water: read your utility’s Consumer Confidence Report. EPA requires community water systems to send one to customers every year by July 1, and you can look yours up with EPA’s CCR search tool or call the utility (U.S. EPA).
• For a lab test: EPA links each state’s drinking water laboratory certification program, which lists certified labs you can pay to test a sample (U.S. EPA).
• On a private well: EPA and CDC both say to test at least once a year for total coliform bacteria, nitrates, total dissolved solids, and pH, and to test again after any change in taste, odor, or color (U.S. EPA; CDC). EPA does not regulate private wells; your state or local health department can help.

If only the hot water is brown, the City of Thornton’s water heater flushing steps show what the job involves. If pressure has also dropped, see low water pressure and what a repipe costs.