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Applying Science To Solve Watershed Problems

The Water Survey is active in the watershed science area with several ongoing projects and other exciting projects on the horizon. The main activities encompass hydrologic and water quality monitoring, watershed model application and development, watershed assessment, and stream restoration.

These research activities assist resource planners and managers who have come to realize that "Integrated Watershed Management" is the only way to solve many complicated and linked water and land resource problems such as non-point source pollution; sedimentation in rivers, lakes, and wetlands; water quality in streams and lakes; flooding restoration of wet-lands and aquatic habitats, etc. To be effective and successful, integrated watershed management must be based on good watershed science, which the Water Survey can provide based on long-term data sets and modeling capabilities.

Watershed Monitoring

Active watershed monitoring projects involve Lake Decatur, the Cache River, and Lake Pittsfield. Monitoring the hydrology and nitrate concentration at eight gaging stations within the Lake Decatur watershed continued for the sixth consecutive year. These data are providing reliable nitrate loading information under varying climatic and land-use conditions. This long-term data set can be used to establish a reliable baseline for evaluation of impacts of land-use changes and projects. More intensive data being collected during storm events will improve nitrate load computational methodology and calibration and verification of a dynamic watershed model.

Data collection continues for the Lower Cache and its tributaries and Heron Pond in the Upper Cache River. Some of the hydrologic and sediment data for selected stations are being processed with funding from the Department of Natural Resources (DNR).

The Lake Pittsfield Project is monitoring the effectiveness of water and sediment control basins (WASCOBs) to reduce sediment delivery to the Pittsfield drinking water reservoir. Approximately 25 percent of the reservoir’s water storage capacity has been lost to sedimentation. The city will pay $1 million to dredge some of the lake in 1998. To reduce future dredging costs, the city entered a watershed conservation program with the Non-point Pollution program of the Illinois Environmental Protection Agency (IEPA), the Pike Soil and Water Conservation District, and the Natural Resources Conservation Service. The 36-acre WASCOB at the upper end of Lake Pittsfield has been successful with over 95 percent sediment trapping in 1998. Smaller WASCOBs in the upper watershed have not yet shown sediment reductions at stream sampling stations.

Stream erosion downstream of the WASCOBs is partially responsible for the masking of sediment trapping efficiency in the basins. The Illinois Department of Agriculture and the IEPA funded a series of low stone grade controls where bank erosion was massive. The incising stream channel was transformed into a series of stone riffles and deep pools during the 1998 spring floods. Sediment deposition below massive erosion sites was flushed without further bank erosion. Re-vegetation of the banks with dogwoods and grasses was completed by July 1998.

Watershed Modeling

The Water Survey has been involved in modeling watersheds using existing models, and evaluating land-use management in reducing flood and agricultural pollutants in streams and lakes. We also are developing new model codes to overcome weaknesses of existing models.

Currently we are developing a Dynamic Watershed Simulation Model (DWSM) using physically based governing equations to simulate propagation of flood waves and entrainment and transport of sediment and all commonly used chemicals for agricultural and rural water-sheds. This effort is partially funded by the Illinois Groundwater Consortium.

The model has three major components: hydrology, sediment, and pollutants. The hydro-logic component simulates propagation of flood waves and has been tested on the watershed of Lake Decatur in the Upper Sangamon River basin. We have collected flow, sediment, and water quality data (specifically nitrate-nitrogen, phosphate-phosphorous, and atrazine concentrations) during severe storms at the Big Ditch station, which drains a 38-square-mile sub-watershed of the Lake Decatur watershed. These data will be used to test all three DWSM components on the Big Ditch sub-watershed. Similar data will be collected from several established stations around the Lake Decatur watershed to test the three DWSM components on the larger watershed.

Researchers Susan Shaw and Maitreyee Bera obtain a depth-integrated sediment sample at Big Ditch after a severe storm.

Watershed Assessment

In a continuing effort to provide scientific data and analysis to support the planning efforts of the watershed-based Ecosystem Partnerships, the Water Survey has prepared assessment reports on water resources issues for selected partnerships. Six assessment reports have been prepared for the following areas: the Illinois River Bluffs, the Spoon River, the Driftless Area in northwestern Illinois, the Lower Rock River, the Sinkhole Plain region in southwestern Illinois, and the Sugar River in northern Illinois. The reports use existing data and information from the Water Survey and other agencies to characterize the climate; air quality; land-use practices; erosion and sedimentation; stream, lake, and wetland hydrology; and surface and ground-water availability for each area.

Watershed Restoration and Rehabilitation

The Waukegan River project has stabilized eroding banks in the city’s parks and has restored fish habitat to the river. The measures provided structural bank support below the water surface with wooden fish shelters (lunkers) and interlocking concrete jacks (a-jacks).

The U.S. Environmental Protection Agency National Watershed Monitoring Program has tracked the stream fisheries response to the implemented practices. There were increased fish numbers at the stabilized bank sites but no increased numbers of fish species. The series of low rock weirs installed in 1995 to increase pool depth and rocky riffle habitat in the stream stabilized reaches and helped increase the number of fish and the number of fish species. In 1997, the Index of Biological Integrity remained high at one site but dropped to degraded levels at another as fish kills decreased fish numbers and species. Large numbers of dead fish were observed on two occasions, but no toxicant was found at the time. Automatic water sampling stations were installed to obtain data from selected flood events in 1998. Bioassays and water chemistry analysis found no evidence of toxicity on the two floods sampled this year.

Illinois Nutrient and Sediment Assessment

With other offices in DNR, IEPA, and the Illinois Department of Agriculture, the Water Survey is continuing to lead the preparation of a report on nitrogen, phosphorous, and sediments in Illinois surface and ground waters. The report will address the sources, transformations, and fates of these pollutants, and identify variations in their concentrations and loads over time.

Upcoming New Initiatives

Sediment and Nutrient Monitoring Network

The Water Survey, in cooperation with the U.S. Geological Survey, is developing a sediment and nutrient monitoring network in the Illinois River basin to monitor the effectiveness of the Conservation Reserve Enhancement Program (CREP). The Illinois River program is a result of an assessment between the state and the U.S. Department of Agriculture to implement conservation practices in the Illinois River watershed over a 15-year period to improve water quality and habitat for wildlife.

Two program goals are to reduce sediment and nutrient (phosphorus and nitrogen) loadings to the Illinois River by 20 and 10 percent, respectively. Field monitoring will assess the effectiveness of CREP. The Water Survey has completed preliminary discussions with the Watershed Management Section of DNR on the type of monitoring needed. A sediment and nutrient monitoring network is expected to be in place for 1999.

Kankakee River Basin

The Water Survey will be initiating a hydrologic and geomorphic analysis for the Kankakee River basin in support of the Kankakee River Basin Partnership. The plan includes compilation of hydrologic data, a sand bar survey, and a channel geometry survey. The Water Survey has conducted several hydrologic, hydraulic, and sediment transport studies on the Kankakee River in the past in relation to sand-bar movement along the river and impacts of

Stream stabilization using artificial riffles to improve habitat quality on the Lake Pittsfield watershed.

channel modifications in Indiana. The Kankakee River Basin Partnership has requested that the Water Survey conduct some detailed data collection and analysis to assist them in developing programs to manage the river better so it can continue to serve as a source of drinking water and for recreational purposes.

Pilot Watershed Program

The Water Survey has been participating in the development of the state’s Pilot Watershed Program initiative. This interagency program is being developed through the Watershed Management Committee of the Natural Resources Coordinating Council to coordinate and evaluate watershed management activities. Using state and federal agency funding priori-ties, the Pilot Watershed Focus Group found that the interests of four agencies occurred in portions of four major watersheds (Spoon, Cache, Embarras, and Kaskaskia) so all agencies could work cooperatively.

The Pilot Watershed Program assists with coordinating ongoing activities and programs among participating agencies. The goal of the program is to provide a forum for local producers and landowners to improve their watershed; streamline landowner access to funding; explore an opportunity to evaluate the effectiveness of watershed management practices, with the potential to improve practices and reduce implementation costs; and provide outreach activities. The Water Survey is a member of the Pilot Watershed Focus Group and will lead the hydrologic and water quality data collection efforts in the four pilot watersheds. The Water Survey will install and maintain streamgaging stations and collect sediment and water quality data beginning in the fall of 1998.

Illinois River Decision Support System

The Water Survey has initiated the development of the Illinois River Decision Support System (DSS) in response to the Integrated Management Plan for the Illinois River water-shed. Within the context of this plan for the Illinois River watershed, it is apparent that there is a need for an integrated DSS that can answer systemic questions related to surface and ground-water issues.

There is currently no integrated tool to assess, evaluate, and predict hydrologic and water quality responses to natural and/or human-induced changes in the physical environment of the Illinois River basin. There are, however, several databases and different surface and ground-water models for segments of the river basin that are not interconnected and compatible.

There are no systematic evaluation processes or tools that can enable us to evaluate the interaction of surface and ground-water re-sources in the watershed and their impact on the movement of water, sediment, and pollutants throughout the watershed. Development of an integrated DSS will enable decision makers to answer "what-if" questions on the hydrologic and water quality response of the Illinois River system to climate shifts and fluctuations, land-use changes, changes in regulations and water management practices, and other scenarios that may evolve over time.

The Illinois River DSS will integrate databases and models needed to address surface and ground-water issues raised in the integrated management of the Illinois River basin. Once the DSS is developed, a variety of scenarios of future changes will be developed and evaluated to model the physical environment and society that could affect the river. Modeling outcomes will include estimates of population change, ground-water and surface water use and management, ground-water recharge, runoff, water law, land-use practices, and climate shifts and fluctuations. Using various combinations of these variables as input, the DSS will generate information on the most likely outcome in terms of water quantity and quality for different time and spatial scales with the Illinois River basin.

 


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Managing and Understanding the Illinois and Mississippi Rivers

Some of the nation’s major rivers—the Illinois River, the Mississippi River, and the Ohio River—border or transect the State of Illinois, which contains more than 13,000 miles of rivers and streams. Essentially all of the more than 300 miles of the Illinois River flow through Illinois, which is bordered on the west by 580 miles of the Mississippi River and on the south by 133 miles of the Ohio River. Because these important waterways play a major role in the socioeconomic and environmental health of our state, understanding these large rivers is essential in developing and implementing the best management methodology for them. Water Survey scientists and engineers are at the forefront of research and data collection efforts for two of these rivers, the Illinois and the Mississippi.

River Bank Erosion of the Illinois and Upper Mississippi Rivers

For the first time in the history of the Illinois and Mississippi Rivers, Water Survey scientists and engineers have completed an inventory of all bank erosion sites on both rivers. They were assisted in this effort by personnel from four District Offices of the U.S. Army Corps of Engineers (USACOE), the University of Iowa, and a private consultant hired by the USACOE.

Approximately 2,200 river bank miles of the Upper Mississippi River (from Cairo, Illinois, to St. Paul, Minnesota) and 600 river bank miles of the Illinois River (from Grafton to Joliet) were surveyed. Colored maps were made for an evaluation of selected bank erosion sites to ascertain the causes of erosion and to classify erosion processes. The document resulting from the study will be an invaluable tool for managers, engineers, government officials, and the general public as a historic reference point and to help formulate future management alternatives. The USACOE will use results from this research in their Upper Mississippi River -Illinois Waterway System Navigation study.

Physical Changes Associated with River Traffic on the Illinois and Upper Mississippi Rivers

Barges on the Illinois and Mississippi Rivers transport tremendous amounts of commodities, an extremely important contribution toward the economic vitality of the state. A fully loaded barge convoy can move up to 11 miles per hour and occupy about 9 to 10 percent of the water area on the Illinois River (a volume of 105 feet by 1,100 feet to a depth of 9 feet).

Bank erosion on the Illinois River.

Early in the 1980s, Water Survey scientists and engineers began pioneering research to determine the hydraulic and hydrodynamic changes associated with this type of river traffic. Although the research was interrupted for about a decade, the project has been completed with support from various entities.

Research results show that in some instances, and depending upon the size of the river, river traffic can alter flow velocity, increase suspended sediment concentrations and turbidity, and generate waves and drawdown. Some of these disturbances could last for a while. The USACOE is using the results in their Upper Mississippi River - Illinois Waterway System Navigation study.

Restoration of Large River Ecosystems and Importance of Hydraulic and Hydrologic Analyses: La Grange Pool on the Illinois River

Several factors affect the ecosystem of any river, including water regimes, floods, soils, and biodata. Formulating restoration techniques for river ecosystems requires a clear understanding of floods of lesser magnitude than the 1993 Flood and their impact on river ecosystems. Working together with environmental scientists and economists, Water Survey scientists and engineers are analyzing these interconnections to determine effective use of hydraulic and hydrologic inputs to manage large river systems such as the Illinois waterway.

A one-dimensional unsteady flow model, UNET, was used to determine not only the flood stages along the La Grange Pool on the Illinois River but also to estimate the extent of stage reduction if all levees were removed. An increase or decrease in floodplain vegetation can alter flood stages, which, along with flood durations, play a major role in river ecosystems. This research may prove useful in managing large rivers.

Illinois River Flood Mitigation by Conversion of Selected At-Risk Levee Districts to Managed Storage Areas

Water Survey scientists and engineers have been evaluating the possibility of converting areas behind at-risk levees on the Illinois River into temporary flood storage, thereby not only decreasing the flood stages of lesser magnitude floods, but also enhancing aquatic habitats within these areas. Use of unsteady flow models indicates that a lateral controlled levee opening approximately 1,000 feet wide by 4 or 6 feet deep could prove viable for flood management.

Converting six levee districts into managed flood storage areas could reduce peak stages. This concept assumes that floodwaters will gradually return to the main waterway after the main flood passes the temporary storage area. This option could be a viable alternative in the future management of floods along the Illinois River, especially in the Peoria to Grafton reach.

Barge traffic on the Illinois River.


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Developing Effective Methods for Improving the Quality
of Illinois Lakes

Many government regulations and programs have been implemented to help establish water quality guidelines for our lakes, and the Water Survey has long been active in lake studies that include monitoring, diagnostic and feasibility studies, and water quality evaluations.

In 1972, the U.S. Congress amended Section 314 of the Federal Water Pollution Control Act to regulate the nation's pollution sources and to restore its freshwater lakes. In 1977, the Clean Lakes Program (CLP) was established pursuant to Section 314 of the Federal Clean Water Act. Under the CLP, managers of publicly owned lakes can apply for and receive financial assistance from the U.S. Environmental Protection Agency (USEPA) to conduct studies on the lakes.

The Illinois Environmental Protection Agency (IEPA) is the coordinator of these projects in Illinois. The Illinois studies include:

To date in Illinois, more than 600 lakes have been assessed under the State Lake Classification Survey, and more than 30 lakes have been the subject of Phase 1, 2, or 3 studies. Studies either have been completed or are in progress for more than 20 lakes (Phase 1) and 10 lakes (Phase 2). Two Phase 3 studies also have been completed.

The Water Survey has assisted the IEPA in conducting more than 120 State Lake Classification Surveys, eight Phase 1 studies (Fox Chain of Lakes, Lake Catherine, Rend Lake, Dawson Lake, Johnson Sauk Trail Lake, Lake George, Wolf Lake, and Vienna Correctional Center Lake), one Phase 2 study (Lake Pittsfield), and two Phase 3 studies (Frank Holten State Park Lake and Lake Le-Aqua-Na).

The Illinois CLP is modeled after the federal program and offers a similar grant program for studies of Illinois lakes. Federal CLP funds were not available in the early 1990s. But in 1996, the IEPA began receiving state funds pursuant to the passage of "Conservation 2000", a long-term comprehensive natural resources protection bill.

Otter Lake

Riprap protects the Otter Lake shoreline.

One of the 1996 Illinois CLP awards was granted to the Auburn, Divernon, Girard, Pawnee, Thayer, and Virden Water Commission to conduct a diagnostic/feasibility study on Otter Lake in Macoupin County. Based on the results of the 19-month diagnostic study, the major problems of Otter Lake have been identified:

The primary objectives of the lake management program proposed for Otter Lake are to improve the lake water quality and minimize the influx of sediments and nutrients from the watershed. Specific objectives include:

Big Marsh in the Lake Calumet watershed is one of the remaining significant wetlands in the Chicago area.

Pollution control and restoration measures proposed for Otter Lake primarily involve watershed management and the use of best management practices for farming and erosion control. In-lake treatment and control measures will involve lake destratification and relocation of the raw water intake. The alternatives for pollution control and restoration measures include:

Managing watershed soil erosion and controlling Non-point pollution sources are ongoing projects at Otter Lake, subject to the availability of funding. Recommendations include replacing the existing 2-horsepower destratifier motor with one 5-horsepower motor ($3,500), installing an additional Aspir-Air destratification system at the south basin ($60,000), and relocating the water intake ($35,700). Approximately 18,400 linear feet of materials (mainly riprap) have been installed at Otter Lake to stabilize the shoreline. A significant amount of eroded shoreline still is in need of stabilization and continues to add sediment and nutrients to the lake. Shoreline stabilization with riprap is recommended on all eroded areas totaling approximately 160,000 linear feet. Riprap would be placed along the shoreline 2 to 4 feet below and 2 feet above the normal pool (spill-way elevation). When possible, grading the shoreline to a 2 (horizontal) to 1 (vertical) slope is recommended prior to riprap installation. The estimated cost of riprap stabilization using crushed stone is approximately $30 per linear foot. For the moderate and severely eroded areas, a 2-foot height of gabions would be placed at the bottom of the bluff. The estimated costs are presented above. The total cost for shoreline stabilization is estimated at $5,954,000. If this work is performed by personnel from the Department of Corrections, the cost would be much reduced. Once implemented, the proposed lake restoration program will impart a wide range of water quality and aesthetic improvements to Otter Lake. Stabilizing 160,000 feet of shoreline will reduce sediment loading and prevent further degradation and loss of valuable shoreline. After riprap and gabion installation, the aesthetic appearance of the lake will be improved. The ongoing watershed management and Non-point pollution source control are effective measures for reducing sediment and nutrient loading, and turbidity entering the lake. These activities will improve water quality of the upper end of the lake and will reduce atrazine input to the lake. Upgrading the existing destratifier in the north basin and the installation of a new destratifier in the south basin will eliminate the anoxic conditions in the hypolimnion, especially during the summer months. Subsequently, it will increase fish habitat and reduce regeneration of phosphorus, nitrogen, manganese, iron, and hydrogen sulfide from the lake bottom, thereby improving raw water quality entering the water works and reducing water treatment costs. If the water treatment intake is moved to the south basin, benefits expected include improved raw water quality, lower atrazine concentrations, and reduced cost of water treatment.

According to Water Survey measurements made in 1998, untreated shoreline areas are categorized as:

Shoreline erosion

Not defined (dam face)

Minimal (<3 feet)

Moderate (3 to 8 feet)

Severe (>8 feet)

Length (feet)

5,260

121,600

33,300

5,140

Total cost

Estimated cost

NA

$3,648,000

$1,998,000

$ 308,000

$5,954,000


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Applying Science for Better Management and Protection
of Our Ground-Water Resources

Ground water is important to the health of our state’s population, economy, and ecosystems. The quantity and quality of the state’s ground-water resources have played an important role at the Water Survey since its inception in 1895 when typhoid and diphtheria were common contaminants of drinking water sources. Fortunately, with modern engineering, those diseases are no longer the threat they once were to our water supplies. The search for plentiful quantities of good quality water continues, and ground-water scientists at the Water Survey continue to search for new sources of ground water, provide yield estimates on known sup-plies, and conduct research on contaminants that could affect the quality of these resources. Protecting ground-water resources from contamination, as opposed to remediation after contamination occurs, is the economical way to maintain the quality of ground-water resources. New and improved methods for field data collection and subsequent manipulation and presentation of that data have greatly enhanced our scientists’ ability to examine, understand, and interpret the data that have been collected. We now can convey technical matter in a manner easily understood by the public and local officials so they, in turn, can make informed decisions about how best to manage their resources. Turning technical data into useful information for the citizens of Illinois is a key to the success of the Water Survey’s ground-water programs. A summary of three selected projects illustrates a portion of the activities in which the Water Survey helps to better manage and protect our ground-water resources. In each of these studies, innovative approaches to regional and site-specific investigations were based on the historic information archived at the Water Survey and the Geological Survey. Ground-water well construction reports were the foundation for hydrogeologic assessment in each of these areas. This information is collected, managed, disseminated, and archived at each Survey as a basic resource for scientists and the general public. This basic information is a key component in ground-water assessment activities which, when used with innovative approaches, foster better management and protection of one of Illinois’ vital resources.

Potential Ground-Water Resources for Springfield

Assistant hydrologist Joe Karny collects a ground water
sample from a monitoring well while the Geological Survey’s
Geoprobe retrieves a soil core for pesticide analysis.

To help meet Springfield’s water demands during drought conditions and provide additional water for the city’s growing population, City Water Light and Power is analyzing the feasibility of developing additional water supplies to supplement Lake Springfield. Water Survey scientists assisted by examining three ground-water resource alternatives for the potential to provide 12 million gallons per day (mgd). These alternatives included development of ground water from sand-and-gravel deposits along the Sangamon River, from similar deposits along the Illinois River west of Jacksonville, and from the large sand aquifer underlying the Havana lowlands of Mason County. Based on a year-long review and compilation of material in the historical files of the Water Survey’s extensive records, only two alternative sources are considered feasible using a reasonable number of high-capacity wells: the Illinois River bottoms west of Jacksonville and the Havana lowlands of southern Mason County.

Potential Ground-Water Supply for Bloomington-Normal and McLean and Tazewell Counties

In 1993, with funding from the Long Range Water Plan Steering Committee, a group of officials from Normal, Bloomington, and McLean and Tazewell Counties, and ground-water scientists from the Water Survey and Geological Survey began a study of the sand-and-gravel aquifers in southwestern McLean and southeastern Tazewell Counties. The study had two goals: 1) to determine the potential for the Sankoty-Mahomet Sand aquifer to supply 10 to 15 mgd, and 2) to determine the possible effects on ground-water levels and existing wells that might occur from such a water supply development. To complete this study, a three-dimensional ground-water computer model was created to simulate ground-water movement across an 1,100 square-mile area. Model input was based on extensive file data maintained by the two Surveys and supplemented by an extensive field exploration program. Model results show that more than 15 mgd can be sustained by the Sankoty-Mahomet Sand aquifer with varying impacts on existing wells, depending on the location of the proposed well field. By placing a well field where the aquifer is thickest, where it is connected to shallower aquifers or the Mackinaw River, and where it is away from aquifer edges, maximum well yields can be obtained while minimizing effects on existing wells. This project relied on inter-Survey mapping coordination and used state-of-the-art computer graphics and modeling technology to solve a traditional aquifer yield problem.

Chemist Tom Holm
and geochemist Walt Kelly collect ground-water
samples from monitoring wells as an
impoundment is flooded for waterfowl
at Lake Depue Wildlife Management Area.

Pesticide Occurrence in Large-Diameter Wells

The Water Survey and the Geological Survey have shown that the occurrence of agricultural chemicals in shallow, large-diameter dug or bored wells is much greater than for drilled wells of similar depth. It has been surmised that the construction of these types of wells may be at fault because the wells often are not properly sealed against surface leakage. At present, the source of agricultural chemicals found in these wells is not known. The objective of this project was to conduct a field study to determine whether the source of agricultural chemicals found in large-diameter wells is related to current and past on-field applications of agricultural chemicals. Principal investigations were con-ducted on a farmstead in Edgar County. At this farm, 13 monitoring wells were nested at six locations around the farmyard. Atrazine was routinely detected in one monitoring well (0.15 - 15.1 micrograms per liter ormg/L) and in the large-diameter farm well (n.d. - 0.69 mg/L) but not in other monitoring wells situated closer to surrounding fields. The same monitoring well also contained the atrazine degradates desethylatrazine and desisopropylatrazine. Nitrate concentrations in the large-diameter farm well were always 10 - 15 milligrams of nitrogen per liter. Another monitoring well, installed near the edge of a neighboring field, contained similar nitrate concentrations. But other monitoring wells also located near field edges contained much less, sometimes non-detectable nitrate concentrations. Sampling of wells for other parameters as well as geophysical testing of two underlying sand bodies also was conducted. This investigation suggests that movement of pesticide over several hundred feet may have occurred at this site. An old herbicide spill is a suspected source of the contaminants; however, it is also apparent that, even in what may be considered a low-risk hydrogeologic setting such as this, contamination of underlying sands and movement in interconnected sand bodies toward large-diameter wells is possible.

 

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