Harlem WWTP - Secondary Treatment Plant in Blaine County, Montana

Harlem WWTP is a municipal wastewater treatment facility located in Blaine County, Montana, serving a small community of 795 residents. The plant is situated in the rural plains of north-central Montana, near the town of Harlem. The facility operates with secondary treatment, which is the standard level required under the U.S. Clean Water Act for municipal plants. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 261,190 gallons per day and currently treats an average of 200,630 gallons per day, indicating it is operating below its capacity. The treated effluent is discharged into local waterways that ultimately drain into the Missouri River Basin. The plant plays a key role in protecting the region's water quality, particularly the Milk River and its tributaries, which support agricultural irrigation and aquatic habitats in the semi-arid landscape.

The plant discharges into the Milk River watershed, a tributary of the Missouri River, which flows into the Mississippi River and eventually the Gulf of Mexico. The Milk River supports diverse aquatic life and is an important water source for agriculture in the region. The plant's secondary treatment helps reduce nutrient loading and protect downstream ecosystems.