Tucker, Young, Jackson, Tull, Inc. (TYJT) was a key subconsultant with major participation in the design and construction of the 30 million gallon basin at Conner Creek. The basin provides screening, settling, skimming, and disinfection of combined sewer overflows which were discharged untreated from three overflow locations to Conner Creek. Conner Creek extends approximately 4,000 ft. from Freud Street to the Detroit River on the east side of the City of Detroit.

The Conner Creek CSO Control facility is located partially within the creek and consists of four parallel compartments each 60-ft. wide, 550-ft. long and 40 to 45 ft. below grade. The construction cost of the facility at completion is estimated to be about $180 million. The facility is currently in the final stages of construction.

TYJT was responsible for the design of civil, structural, and electrical areas of the work. This work contributed more than 45% of the construction cost of the project. TYJT’s services during construction included providing a full time field inspector, and full range of engineering services such as shop drawing reviews, change orders, RFI’s, periodic site visits, as-built drawings, and start-up and testing.

Project Highlights:

Structural Design: The facility's location within the creek led the facility to be supported by a foundation of approximately 6,900 uplift piles. The facility being 40 to 45 feet below grade and the lateral pressure due to the soil and ground water led to the design of heavy-duty walls with thicknesses in the range of 4'-6” to 5'-6”. Approximately 100,000 cubic yards of reinforced concrete was cast for construction of this facility. Pre-cast units including precast girders and double tee units were used to cover over 130,000 SF of the roof area. Structural systems were designed to install flushing reservoirs, launder weirs, baffle walls, training walls, sump wells, control gates, platforms, stairway systems, ladders, secondary containments, and other miscellaneous support structures. Critical sequencing of construction was required to of maintain the ability to pass a flow of over 10,000 cubic feet per second from the existing Outfalls to the Detroit River via construction site. Extensive evaluation of existing structures affected by the operation of the new CSO facility resulted in providing structural modifications to the existing structures such as raising surge and discharge weirs of the Conner and Freud storm water pumping stations, replacement of existing timber backwater gates with roller gates to increase in-system storage, modifications of the existing conveyance conduits to prevent uplift when dewatered and construction of weirs and dams in the system to divert the dry weather flow. Superstructure buildings covering over a 36,000 sq. ft. area were designed to provide process and administrative services.

Civil Design: The civil design included rehabilitation of approximately 5,000 lineal feet of existing 48” to 63” diameter brick sewer and installation of approximately 1,000 lineal of 48” diameter new sewer connecting the new facility to the existing Detroit River Interceptor (DRI) for dewatering purposes. A thorough evaluation of all utilities was required for the new facility and coordination was needed with utility companies to ensure that conflicts with other utilities would not occur during construction. A detention pond was designed to restrict storm water discharge to the existing DRI. The project also included the design of access roadways, paving, grading, fencing, and other general civil site work for the entire facility.

Electrical Design: The electrical design involved a thorough evaluation of the electrical power demand required by all process, mechanical, lighting and other auxiliary loads and design of duck banks, conduit routing and MCC's to provide power to the various equipment. Design of lighting plans for the entire facility was provided. Design of the Grounding System, Security System, Fire Alarm System, Gas Detection System, and Communication System was also provided.

Status of Project:
The Project is substantially complete and is under commissioning.