Illinois Route 161 Utility Engineering

Centralia, Illinois

As part of our existing work order contract for the Illinois Department of Transportation, SAM provided a Subsurface Utility Engineering (SUE) study of 3-miles through the city of Centralia in Marion County, Illinois. This project was performed along IL 161 supported the design of future improvements. SAM coordinated with the District upon Notice to Proceed and were able to designate 46,000 lineal feet of underground utilities and map an additional 30,000 LF of storm and sanitary drainage. SAM also completed a retracement of the existing storm water network and provided field surveying to document the horizontal location of the existing facilities throughout the project corridor.

SAM utilized of industry standard geophysical designating equipment to perform these services. SAM overcame technical challenges with a gas main that posed difficulties in designating and required an extensive amount of troubleshooting for a non-locatable cast iron line. Due to the material of the target gas main, it required isolation by designating several lateral services and it was necessary to use a Pipehorn 800-HL system. This equipment operates at a very high frequency and requires skill and a solid understanding of buried utility characteristics to ensure accurate utility type confirmation due to the risk of “bleed off” which could occur. SAM was also responsible for managing a DBE sub-consultant, and we thoroughly reviewed and provided QA/QC prior to utilizing their data.

The project was successfully completed on time and on budget.

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