City water officials said Wednesday that the green tinted water in an east Carson City neighborhood was likely the result of too much chlorine inside the local water system.
"Our speculation (is) that tint of color came from the higher concentrations of chlorine in the well to counteract hydrogen sulfide," said Curtis Horton, the public works deputy chief. "That is likely what caused our discolored water."
Hydrogen sulfide, which often occurs in well water, produces a rotten egg odor.
Lab results also showed "slightly higher" levels of naturally occurring iron and manganese in one of the two wells that feed the neighborhood on Darla Way, which may have reacted with the chlorine to create the green color, Horton said.
"That's common in most neighborhoods, if you have ever cut into your own water line, you'll notice that brown film in the pipe, that's iron and manganese," Horton said.
He said the chlorine may have reacted with the copper lining inside water pipes, which also could discolor the water.
Two homeowners on Darla Way noticed the greenish water last week. The city took water samples Monday. The lab results came back yesterday.
Horton said the city will flush the well and adjust chlorine levels. He said the discoloration is harmless.
"We will continue to monitor the situation and talk with the residents that were unhappy," Horton said. "We will resolve their issue whatever it takes."