Comanche County, Oklahoma: drinking water report. Comanche County in southwestern Oklahoma has about 121,000 residents, with Lawton as the county seat.
Comanche County in southwestern Oklahoma has about 121,000 residents, with Lawton as the county seat. Fort Sill – one of the Army's most important training installations – dominates the northern portion of the county. Water comes from Lake Lawtonka and Lake Ellsworth, managed by the City of Lawton. The semiarid climate and military presence shape the county's water quality profile.
Fort Sill has confirmed PFAS contamination from AFFF firefighting foam used at multiple fire training sites across the installation. According to the Army's 2024 environmental investigation, monitoring wells near the base's primary fire training area show PFOS at 75 ppt – well above the federal MCL. The contamination has been detected in off-base monitoring wells in the area between the base and Lawton.
Lawton's lake-sourced water supply is separate from the groundwater contamination, but the EPA's UCMR5 data detected low-level PFAS in the municipal system. A 2024 Oklahoma DEQ water quality report found elevated manganese in Lake Lawtonka during summer stratification events, requiring enhanced treatment during those periods.
Comanche County residents near Fort Sill on private wells face the highest PFAS exposure risk. The Army has been conducting residential well testing – if you live within two miles of the base and have not been tested, contact the Fort Sill environmental office.
Check your water for current data. For PFAS, reverse osmosis provides the most effective household removal. Our water filter guide covers systems with certified PFAS performance. Pull your detailed report for trends, and visit our Oklahoma page for statewide context.