Clearing Up Rusty Water

Q: Every spring when I open up our cabin and turn the water on for the summer season, there is an iron or rust color that only comes out of the cold water faucets. It takes a very long time for the water to clear up. What can I do to alleviate this problem? The cabin is 38 years old and there are a few copper pipes, but most of the pipes are cast iron. I pour regular antifreeze in toilet and sink traps, I blow the lines out for winter and I drain the hot water heater. I sincerely hope you can help me with this problem. Thank you kindly for your help! — Ray Pataconi, Green Bay, Wis.

A: Plumbers have differing ideas on what the problem is. One plumber will suggest the rust-colored water is from your well. If you have a private well, not city water, minerals like iron and manganese – common minerals in water – are highly concentrated from sitting half the year, enough to discolor the water drawn. (Shallow wells have an even higher concentration of these minerals.)

Another plumber will say the rust-colored water is likely from small amounts of water that have been sitting in the low spots of your pipes – the water that doesn’t get blown out when you close up the cabin for winter. Since many of your pipes are cast iron, the little water left over would be iron-saturated.

That said, there are a few possibilities for why this discoloration is only coming from the cold water faucets: (1) water softener systems; (2) corroding pipes and (3) settling. If you have a water softener system hooked up solely to your hot water heater, it will filter out most minerals so you might get rust-colored water from the cold, not hot, faucet. Corroding pipes also discolor water. Are the pipes for your cold water faucets a different type than the hot water ones? Another likelihood of the cold water rust problem is this: minerals in the hot water heater will have time to settle to the bottom, making the hot water run virtually clear. When you drain the hot water heater before winter, you flush all of those accumulated deposits out.

If you’re concerned about the quality of your water, you can have your water tested. However, if the water eventually runs clear, and you don’t have this problem during the summer, it’s not something to worry about. It’s hard to pinpoint the exact problem without assessing the entire situation, so if you’re still apprehensive, call a plumber.

One more thing: When you pour antifreeze in the sink traps and toilet bowls, you’ll want to consider using RV antifreeze; it’s less toxic.