Brown water is flowing from some Montgomery and Prince George's taps, but authorities said it is still safe to drink.
The color comes from a little extra manganese, which the Washington Suburban Sanitary Commission said naturally occurs in the water, but they are not removing as much as they normal do. They are trying to combat an increase in "naturally-occurring organic material" in water.
That increase in organic material may have been caused by recent severe weather, WSSC said in a statement.
"Manganese is another naturally occurring mineral present in the Potomac River and is not a health hazard at the level found in our drinking water," the utility said.
They said the public health reasons to combat the organic material outweighs what it called the "aesthetic issue" of the brown water, but the brown water may last for several weeks.
Only people whose water comes from the Potomac Water Filtration Plant are affected. Other customers, served by the Patuxent River, will not see the discoloration.
Anyone who sees the brown water should call WSSC at 301-206-4002 or email firstname.lastname@example.org, because they want to track the discolored water.
For more information on discolored water, click here.
CORRECTION: (August 12, 2017, 12:35 p.m. ET): An early version said the WSSC added maganese to the water. They said maganese naturally occurs in water, but they are not removing as much as they normally do, increasing the amount that shows up in homes.