[11] The nine-member Environmental Protection Commission oversees water, land and air quality issues.

[11] Of the nine commissioners at least 5 members have been identified in 2014 based on public records, to have a conflict of interest, when it comes to stricter environmental protections, particularly the enforcement of the Clean Water Act.

[16]: 8  One in five of the wells contained microorganisms, most frequently pepper mild mottle virus (PMMV), GII norovirus, both human and bovine polyomavirus, and Campylobacter.

[19] The division assists in wildlife population surveys, provides conservation information to the public, and conducts hunter, boater, ATV and snowmobile safety programs.

[citation needed] The 'Parks Bureau' operates and maintains 84 parks and recreation areas with trails and cabins for camping, picnicking, swimming, boating and fishing.

[20] It is responsible for more than 90 state preserves set aside for their natural or cultural significance and supervises programs in recreation planning and resource protection.

[11] In 2011, three environmental groups sued the US EPA to bring DNR's Concentrated Animal Feeding Operations (CAFO) program into compliance with the Clean Water Act.

[23] In September 2021, the Iowa Chapter of the Sierra Club and Trout Unlimited filed a lawsuit against the DNR, alleging the agency improperly approved the manure management plan of a feedlot in northeastern Iowa, and that the plan had incorrect calculations of how much manure could be safely applied to fields nearby the operation.