Save the Illinois River, Inc.
24369 E 757 Rd.
Tahlequah, OK 74464-1949
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EPA TMDL Models Released

Save the Illinois River | Environment | April 16, 2018

Statement by Save the Illinois River President DeniseDeason-Toyne of Tahlequah on EPA TMDL model release announcement on April 16, 2018.



Now the states and other entities can begin finding agreement on how to achieve Oklahoma Scenic River water quality standards. We are anxious to see the modeling for phosphorous, the primary nutrient that is over fertilizing our scenic rivers and Tenkiller Lake.

Sedimentation is also a big problem  which must be addressed.

Perhaps now that TMDL modeling is complete, Oklahoma and Arkansas will require sewage treatment plants to remove greater amounts of pollution and poultry farms will do more to manage their waste.  The TMDLs developed for the Illinois River and Tenkiller Lake will serve as a pollution diet for the watershed.   We should be able to determine what farms and cities must do to have cleaner, safer water.



EPA completesIllinois River Watershed Models


Mediacontacts: Jennah Durant or Joe Hubbard, or 214 665-2200


DALLAS– (April 16, 2018) The U.S. Environmental Protection Agency (EPA) has completedthe Illinois River Watershed Basin and Lake Tenkiller models and released themto the partnering agencies for use. The EPA partnered with Arkansas, Oklahomaand the Cherokee Nation to develop science-based water quality models. Partneragencies can now use the models to evaluate options as they continue to reducephosphorus loadings from sources in northeast Oklahoma and northwest Arkansas.


“Thesetools are great examples of how cooperative federalism works by helpingpartnering agencies achieve their long-term goals,” said EPA Regional AdministratorAnne Idsal. “Over the years we have made great progress by working with states,tribes and local agencies in improving conditions throughout the watershed andwe look forward to continuing this effort.”


Themodels simulate conditions within the Illinois River Watershed and in LakeTenkiller. These models can be used to evaluate options and their ability toimprove water quality. EPA completed calibration as well as a sensitivityand uncertainty evaluation for the watershed and lake models. Within a fewweeks, the EPA will convene the partnering agencies to share information aboutboth models and discuss next steps.


Bothstates have committed to sharing the models and information with stakeholderswithin the impacted areas and will encourage feedback and involvement withintheir jurisdictions. Partner agencies will continue to collaborate during thecoming months.


Since2003, Arkansas and Oklahoma have been working cooperatively to protect andimprove water quality in the designated scenic rivers and to avoid costly,protracted litigation and administrative proceedings. In February 2013,Arkansas and Oklahoma extended and augmented the original Statement of JointPrinciples and Action to make additional commitments to further scientificunderstanding and continue to improve water quality through 2016. Today’srelease of the two models is expected to help partnering agencies continue thisprogress.


Nutrientpollution is one of America’s most widespread, costly and challengingenvironmental problems, and is caused by excess nitrogen and phosphorus in theair and water. Phosphorus levels in the Illinois River can be caused by varioustypes of city and industrial discharges as well as nonpoint source run-off. Thedownstream impacts to Lake Tenkiller may include ‘algal blooms’ and lowdissolved oxygen concentrations in the lake.


Tolearn more about Illinois River Watershed Modeling Program, please visit:


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