Department of Public Works (DPW)

Why is my tap water brown or rust colored?
If you live in the country or have your own private well, the answer to this age-old question is simple… your groundwater has a high iron or mineral content.
If you live in the city that has a municipal water system, the answer to why your water may be less than crystal clear at times is more complicated as there is more than one reason for discoloration. These reasons include one or more of the following…

• Your plumbing, including the underground supply line through your yard, may be made of galvanized iron pipe. Iron pipe degrades over time and rust particles build up in your plumbing. The rusty water can show up occasionally especially when you are using a lot, or just a minimum amount of water. Rust particles can also break loose if your plumbing system is being repaired or a supply line is hit or bumped.
• Water heaters also degrade over time and rust deposits in the bottom of the tank build up and can be flushed through and into your plumbing system when there is higher-than-normal use.
• Water main lines owned by the city can also deteriorate and rust deposits can build up in the lines. These rust deposits can come loose when a main line breaks, a fire hydrant is opened, or there is a large demand for water in your area. City crews will annually, or more often, flush lines to remove rust deposits. This can help in the long run but is not 100% effective in removing discolored water from the distribution system.