FY 23–FY 24 Miscellaneous Sewer Repair
This project includes miscellaneous pipe repairs, manhole repairs, water line installations, force main repairs, pavement removal and replacement, backfilling and other miscellaneous related work throughout UCSD’s service area. The work is assigned on an as-needed basis throughout the year and billed as a time and materials contract. The project was awarded to SNC Construction at the August 2022 Board Meeting. Recent work under this contract included replacing several panels of concrete pavement in the Northeast Plant’s entrance driveway.
Crystal Lake Park Interceptor Crossing
The bridge crossing Crystal Lake, at the north end of the park has contained 2 sanitary sewers within its deck since the 1950s. The bridge was rehabilitated in the 1980s, including a liner to help reduce the rate of corrosion from sewer gases. After a recent inspection it was determined that the bridge again needed extensive repair or replacement.
The project consists of that replacement, which entails installation of a new, prefabricated pedestrian bridge on pile supported concrete abutments, gravity sanitary sewer piping, fiberglass manholes, and landscaping. The existing interceptor crossing including the vault structures will be demolished and removed after new interceptor crossing is operational. The new pedestrian bridge will be a prefabricated weathered steel design with an 8-foot wide concrete shared-use path across it for pedestrians and bicyclists. The new bridge will support two 18-inch diameter Hobas interceptor sewer pipes hanging underneath it. Bypass pumping will be required during the connection of the new interceptor crossing to the existing sewer pipes.
The Board authorized awarding the CLP Interceptor Crossing to Stark Construction at its September 2022 meeting for $1,230,500. Construction of the new bridge abutments are anticipated to start in July 2023 and run thru the middle of August 2023. The new bridge structure is anticipated to arrive in late August with the expected completion being before the end of September 2023.
Rebecca Drive Interceptor Sewer Protection
The UCSD V-C interceptor runs under an unnamed tributary near Ivanhoe Estates, Urbana, Illinois. Both the tributary and interceptor begin north of I-74, cross under the interstate and flow south through a park on the east side of Ivanhoe Estates. The interceptor parallels and crosses the tributary several times. The interceptor pipe is currently exposed at two crossing locations and along the bank of the tributary. The UCSD V-G interceptor feeding into the V-C interceptor is also exposed downstream of the footbridge in the park along the same unnamed tributary.
This project will protect the sanitary interceptor pipes against future erosion and scour so that the infrastructure will remain intact. In-stream structures to direct streamflow away from the pipe and armoring material to protect the pipe will be utilized to provide enduring protection.
The Board authorized awarding the Rebecca Drive Interceptor Sewer Protection to SNC Construction at its July 2023 meeting for $408,000.
Boneyard Creek Interceptor Sewer Protection
UCSD 1923’s interceptor sewer is located along the north bank of the Boneyard Creek just east of the Race Street Bridge. The creek bank in Segment #3 of the Boneyard Creek between Race Street and Broadway Avenue has eroded away exposing the District’s 1923 Interceptor sewer pipe just upstream of the aerial crossing structure. UCSD was concerned that additional bank erosion would undermine the sewer pipe potentially leading to it collapsing into the creek.
UCSD learned that the City of Urbana was planning a Bank Stabilization Project in the Summer of 2023 for Segment #3 of the Boneyard Creek. The City’s project includes installing rip-rap armoring, boulders, rock, and j-hooks to restore and stabilize the creek bank protecting it against future erosion. City Engineering Staff offered to include bank stabilization for the area around the 1923 interceptor sewer as part of their project. UCSD and the City of Urbana executed an Intergovernmental Agreement for a joint stream bank protection project at the May 2023 Board Meeting. The City of Urbana is leading the project and awarded the project to SNC Construction for $258,204.68. UCSD’s share of the project cost is $90,518.26.
FY 24 Pump Station Cathodic Protection Systems
UCSD operates and maintains fourteen steel construction pump stations as part of the sanitary sewer collection system. Five of the pump stations have impressed current cathodic protection systems. Eight of the pump stations have galvanic (sacrificial) cathodic protection systems. Testing revealed that the galvanic cathodic protection systems were not functioning properly at six of the eight pump stations. The galvanic cathodic protection systems were installed between 2010 and 2013 and have reached the end of their service life. One of the pump stations does not have a cathodic protection system.
The impressed current systems are slightly more expensive than the passive systems and require more operation and maintenance activity. However, the impressed current systems will produce enough potential difference to fully meet the National Association of Corrosion Engineers recommended criteria for full cathodic protection.
UCSD prepared a Request for Proposals (RFP) for replacement and installation of impressed current cathodic protection systems for the nine District owned pump stations (8 galvanic and 1 missing system stations). The Board is expected to authorize awarding the FY 24 Pump Station Cathodic Protection Systems project to Johnson Creek at its July 2023 meeting for $259,200.