The following timeline for Illinois River protection events is from the Tulsa World, June 11, 2018
An Illinois River Timeline
1970: Oklahoma designates the Illinois River a scenic waterway (among others) as part of the 1970 Oklahoma Scenic Rivers Act.
1988: Environmental Protection Agency permits Fayetteville, Arkansas, to dump treated wastewater into a tributary of the Illinois River; Oklahoma sues.
1992: U.S. Supreme Court rules Arkansas may dump treated sewage into the Illinois River watershed, but that it must meet Oklahoma water quality standards.
1993: Oklahoma begins gathering data on phosphorous and other pollutants in the Illinois River.
1996: State of Oklahoma issues report detailing high levels of contaminants in Lake Tenkiller.
2003: Arkansas and Oklahoma agree to work together to reduce pollution in the Illinois River watershed.
September 2004: Poultry companies submit plan to reduce chicken litter application in Oklahoma river watersheds. Oklahoma Attorney General Drew Edmondson calls the plan "lacking."
June 2005: Edmondson files a federal lawsuit against 14 poultry companies, accusing them of polluting the Illinois River watershed with chicken litter and seeking damages.
November 2007: Citing data obtained through water and soil samples, the state seeks preliminary injunction banning the use of poultry litter in the Illinois River watershed.
September 2008: Judge rejects state's request for a preliminary injunction to prevent the land application of poultry waste.
October 2008: Poultry industry seeks to have case dismissed because Cherokee Nation has water rights in the watershed.
July 2009: Judge rules that state can't seek millions in damages because it failed to properly include the Cherokee Nation, which claims water rights in the watershed.
Sept. 24, 2009: Federal trial begins in Judge Gregory Frizzell's courtroom.
Feb. 18, 2010: Final arguments in chicken poultry case. After more than eight years, no decision has been rendered.
Feb. 20, 2013: Oklahoma and Arkansas announce joint three-year study of water quality in the Illinois River watershed as a continuance of the 2003 agreement as a “Second Statement of Joint Principals and Actions.” The Scenic Rivers Joint Study Committee, with three members each from Arkansas and Oklahoma, is established.
Oct. 1, 2015: U.S. Environmental Protection Agency makes available for comment a proposed Illinois River Watershed Modeling Program.
Dec. 19, 2016: The Joint Principals agreement yields the Oklahoma-Arkansas Scenic Rivers Joint Phosphorus Study, which is adopted by the Scenic River Joint Study, affirming a scientific basis for standards sought by Oklahoma since 2003.
April 16, 2018: The EPA approves working models for the Illinois River watershed based on the Oklahoma-Arkansas Scenic Rivers Joint Phosphorus Study. State agencies begin meeting to discuss how to implement the models.-0-Additional information supplied by STIR
1984, Save the Illinois River chartered