URS Corporation will be conducting a Sanitary Sewer Evaluation Study (SSES) to identify problems in areas within the sewer collection system that are potentially contributing to flooding problems and other storm related issues. Inspection and testing will be conducted in Sewer Sub Basins 5, 6, 7, and 8 (see map below for locations). The work is scheduled to start the week of December 15, 2014 and estimated completion date for field work is April of 2015. There are two tasks associated with this project. Task 1 of project will consist of Sanitary Manhole Inspection. Task 2 will consist of Rainfall Simulation of Public Property (Mainline Dye Testing).
Task 1 Manhole Inspection:
URS will start the week of December 15, 2014 and completion date is estimated February 2015. Manhole inspection is another tool used to confirm sewer mapping and locate sources of I/I. URS will conduct manhole inspection for approximately 300 manholes. The inspection will consist of a topside inspection noting the condition of all manhole components. The field team will take digital photographs of all inspected manhole structures, noted manhole defects or evidence of I/I, and any previous rehabilitation work observed to have been completed within the structure. Information to be recorded during the manhole survey includes: Basic data, such as silt build-up, visible infiltration or exfiltration sources, hydrogen sulfide odors, structural damage, cracks, open or offset joints, sags, water construction materials, pipe size, depth of manhole, depth to invert, depth of flow, and flow direction.
Task 2 Mainline Dye Testing:
URS will start mid-February 2015 and completion date is estimated April 2015. Mainline testing, which includes testing storm sewers, catch basins or ditches that cross or parallel the sanitary sewer will identify public property sources. These tests include adding non-toxic dyed water to the storm structures and watching to see if dye transfers to the sanitary sewer. During this testing, sewers will be plugged to create a head of water in the storm sewer similar to what occurs during rain events. Most times water is added to catch basins to fill the plugged storm sewer. Dye transfer for a ‘positive’ test is seen in the sanitary sewer. Once identified in the sanitary manhole, a URS owned CCTV camera would be inserted into the sanitary sewer segment found to have dye in it. The CCTV camera will identify any sources from joints, cracks or laterals and quantify the severity and location of the leak. All testing locations and findings would be submitted in a report.
The dyed water testing involves the use of fluorescent dyes that are harmless to the environment, biodegradable, and inert to soils. Green and red dyes may be seen in storm sewers and ditches during the testing. These tests are performed to check for blockages in the storm sewer system, improper connections, and other extraneous water sources entering the sanitary sewer system. By simulating rainfall using dyed water, inspection teams will be able to locate rain or groundwater entry points into the sanitary sewer system.
Crews will be identified by URS badges, field work representative letters, and marked vehicles; and URS crews will not require entry into your house. If you have any questions or require additional information concerning this project, please feel free to contact: Scott Belz, URS Corporation, (216) 622-2345 or notify the field crew in the area.