Monument Sanitation District is located 15 miles north of Colorado Springs, Colorado. It has been in existence since 1963. The District has a sewer system that collects the waste water from the residents and businesses of the Town of Monument west of Interstate 25 and areas outside of the town limits.

The waste water is treated at the Tri-Lakes Wastewater Treatment Facility (TLWWTF), a Publicly Owned Treatment Works (POTW), on South Mitchell Ave. Effluent is discharged from the POTW into Monument Creek, which is within the Fountain Creek Water Shed.

TLWWTF is rated at 4.2 million gallons per day. Presently TLWWTF treats 1.24 million gallons per day.

Monument Sanitation District, Palmer Lake Sanitation District and Woodmoor Water and Sanitation District jointly own the POTW. The three districts have entered into a Joint Use of Facilities Agreement, revised February 9, 2010, that addresses issues associated with the joint ownership, operation and management of the TLWWTF. Each district has a primary and an alternate director which serve as board members of the Joint Use Committee (JUC). The JUC meets once monthly to oversee the business of the TLWWTF.