| Agricultural Operations Permits | 1928-2002 |
| Agricultural Operations Permits, Pictures | 1975-1999 |
| Air Facility Stack Test | 1996-1997 |
| Air Quality Facility Files | 1971-1994 |
| Construction Grant Needs Survey | 1996-2008 |
| Construction Grant Programs | 1976-1997 |
| Construction Permits | 1979-1997 |
| Construction Project Files, Contracts | 1970-1993 |
| Contaminated Sites (Confidential) | Undated |
| County Conservation Board Land Acquisitions | 1930-1988 |
| Departmental Policies and Procedures | 1972-1986 |
| Emergency Response | 1998 |
| Executive Correspondence | 1970-2007 |
| Facility Plans | 2000-2006 |
| Federal/State Programs and Projects | 1985-2008 |
| Flood Plain Permits | 1957-2001 |
| Geological Research, Gold Mines in Iowa | 1880-1962 |
| Groundwater Hazardous Statements | 1999-2000 |
| Groundwater Protection Plan Strategy | 1968-1992 |
| Hazardous Substance Incidents (Spill Files) | 1976-1996, 2001-2003 |
| Hazardous Waste Facility Site Licenses | 1987-1991 |
| Hazardous Waste Management | 1971-2001 |
| History of State Parks and Fish & Game Data, Pictures, Newspaper Articles and Civil Conservation CorpProjects | 1900s |
| Information and Education Programs | 1973-1986 |
| Land and Water Conservation Fund Federal Grants | 1967-1997 |
| Landfills | 1985-1997 |
| Leaking Underground Storage Tanks | 1974-2006 |
| Leaking Underground Storage Tanks, Pictures | 1986-2003 |
| Legislative Liaison | 1973-1988, 2009 |
| Mill Dams | Undated |
| Minutes - Department of Environmental Quality, Transition Team | |
| Minutes - Energy Fund Disbursement Council | 1990-1992 |
| Minutes - Energy Fund Distribution Council | 1990-1992 |
| Minutes - Environmental Protection Commission | 1986-1999 |
| Minutes - Monthly Contested Case Reports, Monthly Attorney General Reports | |
| Minutes - Natural Resources Commission | 1973-1993 |
| Minutes - Natural Resources Commission (Closed Sessions) | 1977-1985 |
| Minutes - Natural Resources Commission Hearings | 1961-1977 |
| Minutes - Natural Resources Council | 1996-1998 |
| Minutes - State Preserves Advisory Board | 1965-1994 |
| Minutes - Statewide Policy Advisory Committee | 1980-1982 |
| Natural Resources Land Inventory | 1985 |
| Photographs, Directors | 1935-1983 |
| Plan Use Planning | 1966-1979 |
| Press Releases | |
| Program Planning and Project Development | 1972-2001 |
| Project Files, State-Owned Lands and Water | 1904-1991 |
| River Basin Duties | 1980-1986, Undated |
| Solid Waste Comprehensive Planning | 1982-1998 |
| Solid Waste Permitted Facility Files | 1972-1995 |
| Solid Waste, Photographs | 1970-1992 |
| Sovereign Land Jurisdiction | 1964-2004 |
| Sovereign Land Jurisdiction, Photographs | 1994-1999 |
| Spill and Groundwater Remediation Projects | 1992-1999 |
| State Land Acquisition Records | 1900-1998 |
| State Park Management | 1915-1997 |
| State Park Management, Photographs of Parks and Preserves | 1907-1979 |
| State Water Plan | 1977-1980 |
| Stormwater, Facilities | 1991-2001 |
| Sulfur Oxide, Modeling Study | 1974-1980 |
| Super Fund Site Files | 1976-2004 |
| Toxic Clean-Up Days | 1990-1994 |
| Treatment Agreements | 1996-2000 |
| Uncontrolled Sites | 1928-2001 |
| Uncontrolled Sites, Photographs | 1951-1997 |
| Underground Storage Tanks, Photographs | 1992-2008 |
| Waster Facility Files, Photographs | 1974-2009 |
| Wastewater Facility Files | 1951-2005 |
| Wastewater Facility Specifications | 1976-2008, Undated |
| Water Quality Planning | 1979-1993 |
| Water Resources Regulation, Construction Permits | 1964-1992 |
| Water Supply Facility Files | 1967-2002 |
| Water Supply Plans and Preliminary Reports | 1996-2009 |
| Water Supply Specifications | 1996-2001 |
| Waterways and Lakes, Saylorville Study | 1968-1987 |