Prosper would pay a Utah company $90,000 to put sensors in sewer manholes and measure where unwanted water is getting into the town's wastewater system, under a purchase on the Town Council's consent agenda Tuesday.
The inflow and infiltration study from RH Borden and Company of Lehi, Utah, was requested by the Public Works wastewater division during budget planning and is a budgeted contracted service this fiscal year, according to a staff memo.
Crews would first capture key dimensions of selected manholes with lidar scans. Level sensors would then record how wastewater moves through the pipes to establish what normal flow looks like. When the readings show excess water, the study would estimate how much and compare sensor sites to find the areas with the worst problems.
The vendor's quote also calls for matching water levels against wet-weather records.
Staff would use the results to decide where to look more closely, including where smoke testing could help locate defects, the memo says.
The March 5 quote breaks the cost into $24,000 for a year of flow monitoring at eight basin sites, $54,400 for a targeted assessment that places up to seven level sensors per mile of a chosen basin, $8,400 for crew mobilization and $3,200 to install the sensors. The company's analysis would rank basins and sensor locations by how much excess flow each one adds.
The memo ties the study to the town's Capacity, Management, Operation and Maintenance program under the EPA, which requires Prosper to find and correct weaknesses that could lead to sanitary sewer overflows or unauthorized discharges. Staff wrote that the data should help the town fix problems before they turn into backups or overflows.
