Lahaina residents from Puamana to Kapalua are asked to reduce their water use and flows into the sewer system because of a problem at the Lahaina Wastewater Treatment Plant, the county departments of Water Supply and Environmental Management said Tuesday.

A clarifier unit at the treatment plant needs repair, which is substantially reducing the ability of the plant to process sewage, said water department spokeswoman Jacky Takakura.

The advisory runs through Tuesday. The water conservation does not apply to irrigation or other water use that does not flow into the treatment facility.

Customers with questions may contact engineer Juan Rivera at the Department of Environmental Management during normal business hours at 270-7268.