The federal Clean Water Act requires DEQ to assess Montana’s water quality and prepare a report every two years. The Montana Water Quality Report and List of Impaired Waters (known as the Integrated Report) combines reporting information for the Clean Water Act Section 305(b) assessment of water bodies and the Section 303(d) list of water bodies that do not meet water quality standards. Water bodies not meeting standards need pollution reduction studies, called Total Maximum Daily Loads (TMDLs). TMDLs also include plans to improve water quality to eventually meet standards.
DEQ has issued the Water Quality Call for Data for the 2020 update to the 303(d) and 305(b) listings
Final Integrated Reports
These documents and supporting files constitute the State of Montana's FINAL water quality Integrated Report submission to the U.S. EPA for the given reporting cycle. This includes both the Section 303(d) List and Section 305(b) Report as required under the federal Clean Water Act.