Durkees Run Interceptor & Earl Ave. Reconstruction Project
The goals of the Durkees Run Interceptor & Earl Ave. Reconstruction project are to divert stormwater from the Waste Water Treatment Plant, improve area wide drainage conditions to reduce street flooding in the Earl Avenue area and east of 18th Street near Lafayette Jefferson High School, and to improve roadway corridors in the area.
Near the high school on 18th Street and along Earl Avenue between State Street and South Street the City has separated existing combined stormwater and sanitary sewer lines. The sewer separation will alleviate capacity problems in existing sanitary sewer further downstream and reduce raw sewage overflows into Durkees Run.
When the overall project is completed, over 100 million gallons of storm water annually will be diverted from the Lafayette wastewater treatment plant while preventing untreated sewage from flowing into the Wabash River.
The project will reduce flooding and satisfy the requirements of the U.S. Environmental Protection Agency and the Indiana Department of Environmental Management.
The project is being completed under the Indiana Guaranteed Savings Contract statute which allows for energy, wastewater, and capital savings, all of which will be realized with this project. Using a Guaranteed Savings Contract allows the City to take advantage of a collaborative process between the City, the City’s Engineer Butler, Fairman and Seufert and the project’s Provider Bowen Engineering Corporation. This process reduces the risk for the City, decreases time to completion, and allows for construction savings to be returned to the City.
Durkees Run Interceptor & Earl Ave. Reconstruction Phase 1
Phase 1 of the Durkees Run Interceptor & Earl Ave. Reconstruction project was constructed between Earl Avenue and Sagamore Parkway on South Street. This phase of the project had to be completed quickly due failure of an existing sewer along South Street that crossed under the railroad tracks to the east of Earl Avenue. Phase 1 was completed during the summer of 2012 while traffic associated with the Purdue population was reduced. The project was completed on schedule and under budget. The sewers under the railroad were repaired and stormwater and sanitary sewers in the area were separated via new sewer installation and sliplining of existing sewers to allow proper discharge to the future project phases.
Durkees Run Interceptor & Earl Ave. Reconstruction Phase 2A
Phase 2A is the second phase of the overall project that consisted of separating the lines running from State Street, through Jefferson High School property, under 18th Street, and ended with two stormwater detention ponds behind Durgan School that outlet to Durkees Run.
The area behind the Durgan Elementary School was purchased in order to construct stormwater detention and water quality treatment ponds. Upon final project completion, stormwater runoff from approximately 1,000 acres of the City will be directed to the ponds for storage, treatment and release to the Durkees Run channel. Existing conditions prior to the implementation of the project allowed for this runoff to be combined with sewage from the City’s sanitary sewer system. During large events this combined sewage would be released directly to Durkees Run.
Additionally, an easement area was purchased east of 18th Street on Lafayette School Corporation grounds just south of the old Pythian Home site. This easement now contains a constructed Stormwater Park to improve the storm water quality and provide an educational opportunity for Lafayette students to learn about ecosystems, environment and the importance of cleaning up our streams for future generations. Large diameter storm sewers will be constructed from the Stormwater Park east to State Street.
Durkees Run Interceptor & Earl Ave. Reconstruction Phase 2B
In order to separate storm water from sewage in the almost 1,000-acre drainage area that contributes to the stormwater detention ponds being constructed as a part of Phase 2A, new sewers were extended north along Earl Avenue. Phase 2B included all work associated with the separation of sewers from Main Street to Kossuth, including water main relocations and corresponding roadway reconstruction and trail improvements.
This phase of the project included the construction of 84-inch diameter storm sewers from the intersection of Main Street and Earl Avenue to the intersection of Kossuth Street and Earl Avenue to replace the existing 60-inch diameter combined sewer along Earl Avenue. Drainage modeling and televising showed that the existing 54-inch and 60-inch combined sewer from the intersection of Kossuth Street and Earl Avenue to the intersection of South Street and Earl Avenue could be salvaged and converted to be part of the dedicated storm sewer line providing the City with a cost savings. A sanitary sewer already existed along the route, allowing sanitary connections to be rerouted from the existing combined sewer. Providing for a dedicated storm sewer in the area eliminated cross connections and allows for only stormwater to be transported to the ponds that were constructed in Phase 2A once the overall project is completed. Phase 2B also included new signals, pavement markings, signage, lighting, and road reconstruction.
Durkees Run Interceptor & Earl Ave. Reconstruction Phase 2C – Projected Completion 2015
When Phase 2C of the project is completed it will connect Phase 2A at State Street to Phase 2B at the intersection of Main Street and Earl Avenue with large diameter storm sewers. The completion of Phase 2C will allow for only stormwater to be discharged to the stormwater detention ponds west of 18th Street and ultimately Durkees Run. Phase 2C will also include trail, new signals, pavement markings, signage, lighting, and road reconstruction.
Durkees Run Interceptor & Earl Ave. Reconstruction Phase 3 – Projected 2015
The City’s original Long Term Control Plan (LTCP), only identified 100 acres for sewer separation and included plans for a project to install a new interceptor sewer along the length of the Durkees Run stream. The required route for this new interceptor sewer would require tree removal, stream crossings, road crossings and installation through residential areas and the Lafayette Country Club Golf Course. Based upon additional engineering and evaluation performed after the LTCP was completed, the City was able to increase the original 100-acre separation area to a 1,000-acres area, which eliminated the need for a second interceptor. However, the existing Durkees Run Interceptor sewer is nearing the end of its useful life and in dire need of rehabilitation. The rehabilitation project will include lining the existing sewer and manhole rehabilitation. The rehabilitation work is significantly less invasive than that of installing a new line and reduces the disturbed area, tree removal, and environmental issues associated with a new sewer installation. The project will be very similar to the Elliott Ditch Sewer Rehabilitation project that was completed in 2008.