Donala Water and Sanitation District, which spans between Gleneagle and southern Monument, informed its customers Friday about exposure to high levels of combined radium in their water supply.

In a notice, the district informed 27,000 residents that it “violated” the Colorado Department of Public Health and Environment’s drinking water requirements.

The limit of combined radium is 5 pCi per liter, but the district averaged 6.7 pCi per liter over the past year, according to the notice.

Combined radium is a substance that can cause chronic health risks such as increased risk of lymphoma, leukemia and bone cancer, among other diseases, the Environmental Protection Agency noted.

The notice informed residents the situation was “not an emergency,” but added that they “may want to use an alternative drinking water supply” and to consult their doctor with health concerns.

Donala Water cited increased water demand from the construction of wells around the Front Range as the cause of the increased level of contaminates.

The water district expects to have the issue resolved by Aug. 31, 2023. The district also said it reduced run times at its water plant and introduced water from Colorado Spring Utilities to reduce the amount of combined radium in the water.