Sanitary Sewer Smoke Testing
City of Valdosta, GA
As part of the City of Valdosta’s Five Year Action Plan, Constantine provided smoke testing services for the evaluation of the City’s sanitary sewer collection system consisting of approximately 300 miles of gravity sewer.
The evaluation activities include the investigation of all manholes and collection system lines via smoke testing to be followed by closed circuit television (CCTV) inspection of sewer lines in high priority areas. The purpose of these investigations was to identify sources of infiltration and inflow (I/I) and to prioritize and schedule collection system repairs.
The gravity sewer system consists of approximately 300 miles of sewer line ranging from 6-inches to 36-inches in diameter. The sewer system was divided into five (5) geographic areas referred to as sub-listings which each contain approximately 316,000 linear feet of gravity sewer. Over the course of five years, Constantine performed smoke testing tasks in one sub-listings per year.
To test the collection system, field crews placed a smoke blower on manholes and used an industry-standard liquid smoke product to generate smoke. Smoke blower manhole setups were conducted such that up to approximately 1,000 linear feet of gravity sewer was tested per setup. Field crews used flow-through plugs to isolate the gravity sewer subject to the testing in order to increase system pressure to better allow smoke to exit defects and travel to the ground surface.
For each line segment tested, information was recorded on a field smoke form which included a sketch of the area with defect locations identified. The field form also included information regarding the defect’s address, ground cover, source, and infiltration and inflow ranking. Additionally, for each defect, field crews collected a mapping-grade GPS position and captured two photographs