What is a TMDL?
Every 2 years the Clean Water Act requires each state to submit a report on the quality of the state’s waters to Congress (Illinois Water Quality Report). Waters that are found to not be meeting the state’s water quality standards for one or more pollutants are put on the state’s list of impaired waters (Illinois 303(d) list). The lakes and streams on this list are then in line for a cleanup plan for the problems that have been identified.
For a copy of Illinois’ Impaired Waters list, see http://www.epa.state.il.us/water/tmdl/303d-list.html
What does TMDL mean?
In layman’s terms, a TMDL is a cleanup plan. It is short for Total Maximum Daily Load. It is an analysis that reports the maximum amount of pollutant which a water body can receive without water quality standards being violated or the use of the water body for activities like swimming, fish consumption, aquatic life support, and public water supply being inhibited.
The TMDL sets pollution reduction goals needed to improve the quality of the impaired waters so that water quality standards are no longer violated and all uses which are designated for the water body are possible.
In Illinois a TMDL is released with a Watershed Implementation Plan that spells out how the pollution reduction goals will be achieved. This plan set limits on pollutants from point source discharges (coming out of pipes from factories and sewage treatment plants) and recommends best management practices (BMPs) for nonpoint source discharges (runoff from streets, lawns and fields). In the case of the West Branch of the DuPage River, the Watershed Implementation Plan is included in the TMDL Plan.
For more general information about TMDLs, see http://www.epa.state.il.us/water/tmdl/
The Problems of the East Branch and West Branch of the DuPage River and Salt Creek
The TMDLs for the East Branch and West Branch of the DuPage River and Salt Creek list problems with the following parameters:
East Branch of the DuPage River Impairments
conductivity, chloride, and dissolved oxygen (DO)
Find the East Branch TMDL at
http://www.epa.state.il.us/public-notices/2003/dupage-river-tmdl/tmdl-draft-report.pdf
Salt Creek Impairments
copper, conductivity, chloride, phosphorus, and dissolved oxygen (DO)
Find the Salt Creek TMDL at
http://www.epa.state.il.us/public-notices/2003/salt-creek-tmdl/draft-tmdl-report.pdf
West Branch of the DuPage River Impairments
chloride and copper
Find the West Branch TMDL (includes Watershed Implementation Plan) at: http://www.epa.state.il.us/water/tmdl/report/dupage/west-branch-draft-tmdl.pdf
In all cases except dissolved oxygen, the parameter is a pollutant which was found in the stream at levels higher than Illinois water quality standards. In the case of dissolved oxygen, aquatic life depends on oxygen in the water. A stream is impaired for DO if the levels measured in the stream fall below Illinois minimum standards.
Illinois EPA’s Suggested Actions to Restore the East Branch and West Branch of the DuPage River and Salt Creek
The Watershed Implementation Plan for the East Branch of the DuPage River recommends these actions:
Conductivity/chloride pollution is addressed by recommendations for BMPs for road deicing activities. A 21 percent reduction in overall chloride application to the East Branch will be needed.
Low dissolved oxygen levels are addressed by:
1) Requiring sewage treatment plants that discharge wastewater to the river to limit pollutants that require oxygen consumption as they are broken down in the stream. Lower limits are set for ammonia and CBOD (chemical biological oxygen demand which is a measure of the amount of oxygen consumed as the organic waste is broken down.) Currently the plants are all discharging at levels below the proposed new limits so no immediate changes in practices are actually proposed.
2) Artificial reaeration of Churchill Woods Lake just upstream of Crescent Blvd.
3) Reducing organic matter getting into the river with stormwater runoff.
Find the East Branch WIP at
http://www.epa.state.il.us/public-notices/2003/dupage-river-tmdl/watershed-implementation-plan.pdf
The Watershed Implementation Plan for Salt Creek recommends these actions:
Copper pollution likely came from the Bensenville South MWWTP. As the limited data is over 8 years old, it is recommended that Illinois EPA take more measurements of copper in Addison Creek and then work with Bensenville to reduce its copper loads if warranted.
Conductivity/chloride pollution is addressed by recommendations for BMPs for the road deicing activities. An 8 percent reduction in overall chloride application to Salt Creek and a 41 percent reduction in Addison Creek will be needed.
Phosphorus pollution in Busse Lake shows a decline from 1994-2000. Delisting of this impairment is recommended. Monitoring should continue to ensure this is a long-term trend.
Low dissolved oxygen levels are addressed by 2 scenarios:
Scenario 1
1) Requiring sewage treatment plants that discharge wastewater to the river to limit pollutants that require oxygen consumption as they are broken down in the stream. Lower limits are set for ammonia and CBOD (chemical biological oxygen demand which is a measure of the amount of oxygen consumed as the organic waste is broken down.)
2) Manage stormwater and combined sewer overflows to reduce pollution.
Scenario 2
1) Remove the dam at river mile 11.6
2) Manage stormwater and combined sewer overflows to reduce pollution.
Find the Salt Creek WIP at
http://www.epa.state.il.us/public-notices/2003/salt-creek-tmdl/watershed-implementation-plan.pdf
The Watershed Implementation Plan for the West Branch of the DuPage River recommends these actions:
Copper pollution Delisting of this impairment is recommended since the only copper exceedance found was considered a data outlier.
Conductivity/chloride pollution is addressed by recommendations for BMPs for the road deicing activities. A 35% percent reduction in overall chloride application in the West Branch watershed will be needed.
The West Branch WIP is found within the TMDL at
http://www.epa.state.il.us/water/tmdl/report/dupage/west-branch-draft-tmdl.pdf
Sierra Club’s Recommendations for Improving the TMDLs and WIPs for the East Branch, West Branch and Salt Creek
1) The contribution which nutrient pollution makes in feeding algae which then depress oxygen levels at night should not be ignored as it has. Both Sierra Club and Illinois EPA monitoring of the East Branch and Salt Creek shows elevated levels of nutrients (phosphates and nitrates).
2) Local watershed implementation councils need to be set up to select the BMPs to be implemented from the recommendations made in the plans. These should involve interested citizens. Sierra Club supports the recommendations aimed at reducing road salt pollution of area streams.
3) Sierra Club supports the proposals for tighter limits on ammonia and biological oxygen demand (BOD) as part of the effort to improve dissolved oxygen levels in the East Branch and Salt Creek. The breakdown of ammonia and BOD in the streams can contribute to oxygen depletion just as nutrient-fertilized algae do. Ammonia is also toxic to fish and other aquatic life.
Important Next Steps
Dealing with the pollution found in stormwater runoff is a part of the recommended actions to solve the road salt pollution problem in the East Branch and West Branch of the DuPage River and Salt Creek. The WIP for Salt Creek also envisions improving dissolved oxygen levels in the creek by reducing the pollution in stormwater runoff. Selecting which BMPs to implement will be a community decision made at the local level. Therefore, it is important that citizens participate in local implementation councils set up to follow the recommendations of the TMDLs and WIPs for all three streams.
Citizens can help encourage communities in the DuPage River watershed to undertake activities that will reduce road salt runoff into area streams. These include:
Storage:
Salt storage piles need to be completely covered (i.e., use of salt domes)
Storage and handling operations should be performed on impervious surfaces
Stormwater runoff from areas where salt is stored should be contained in a suitable area
Application:
Use of calibrated spreaders; trucks can be equipped with ground speed sensors that can accurately control the rate of spreading
Training programs for drivers and handlers should be implemented to improve the efficiency of application and to reduce losses
Snow plow operators need to avoid piling snow on or near frozen ponds, lakes, streams, or wetlands
Other:
Identify ecosystems that are sensitive to salts
Use of alternatives such as calcium chloride and calcium magnesium acetate may be less environmentally harmful to sensitive ecosystems; these alternatives are more expensive than regular salt, but they are less corrosive to bridges and overpasses
In some instances, sand may be used in place of salt to improve traction, but the use of sand may not be appropriate where sedimentation presents adverse environmental impacts