Road commission catches up on catch basin repair
Problem / Genesee County Road Commission maintains 2,000 miles of paved and unpaved primary and local roads and 799 lane miles of state highway in Michigan. Keeping on top of the several thousand catch basins in the 17 townships within the road commission’s jurisdiction is a major challenge. Many are made of brick and date back to the 1920s and 1930s. As they age, catch basin failures have caused collapse and roadway sinkage — and major problems for Genesee County motorists.
Solution / To prevent these major failures and keep traffic flowing, the road commission has committed to repairing catch basins proactively, before they collapse and sink. They’ve worked with a GIS expert and the Genesee County Drain Commission to identify and prioritize catch basins in need of rehabilitation, and most important, the road commission selected an innovative catch basin repair solution, utilizing a centrifugally cast manhole renewal system pioneered by AP/M Permaform.
Result / Using this system, a two-man crew is able to complete a basin rehabilitation in just two or three hours. Under ideal conditions, they can do as many as eight in one day. The system enables contractors and municipalities to complete quality work in short time frames, demonstrating a major return on investment compared to conventional methods. Perhaps more important, by proactively rehabilitating catch basins before failure, the road commission is avoiding the expenses and hazards of emergency repairs. 800-662-6465; www.permaform.net.
Manhole encapsulation system helps eliminate combined sewer overflows
Problem / In the rural area of Honesdale Borough, Pennsylvania, locals like to spend their time enjoying activities such as fishing, rafting and biking. As bicyclists pedaled around town, it became harder for them to overlook the increased cracking of the pavement above their manhole structures. The problem was several combined sewer overflows. The structures were receiving excessive inflow and infiltration, resulting in hydraulic overload conditions that needed to be addressed.
Solution / The Central Wayne Regional Authority enlisted the assistance of Entech Engineering, which recommended the use of WrapidSeal Manhole Encapsulation System from CCI Pipeline Systems. “Entech has been using WrapidSeal on projects for over 12 years simply because it works,” says Bryon Killian, P.E., LO. “Starting in this industry 16 years ago, I personally conducted thousands of manhole inspections and found the manhole riser rings and joint sections were almost always the primary cause of infiltration. In addition to helping prevent I&I, we also use WrapidSeal to ensure pavement life by preventing fines being washed away with infiltration, causing pavement cracking around manhole structures.”
Result / Once these structures were repaired and protected with WrapidSeal, the amount of I&I causing the hydraulic overload conditions during wet weather was significantly reduced, accounting for the elimination of 13 CSOs over the last decade. 800-867-2772; www.ccipipe.com.
City decides to be proactive on manhole protection
Problem / The city of Fairmont, Minnesota’s wastewater collection system utilizes 75 miles of sewer lines with 30 lift stations. During routine inspection, one of the sanitary sewer force main manholes was identified as turbulent. The city decided to take the proactive measure of lining this 2-year-old precast manhole — which has a 6-foot diameter at the base and tapers to 4 feet by 13 feet deep — to protect the asset from any future corrosion and deterioration that would require costly measures to correct.
Solution / “We want to protect our assets. We have seen similar structures deteriorated. This force main sanitary sewer is only 2 years old, but we decided to be proactive and selected CLADLINER to seal and protect,” says Doug Rainforth, the city’s water and wastewater superintendent. The rehabilitation of this manhole was completed from start to finish in several hours. After the surface preparation, involving high-pressure waterblasting, a mortar pump was used to spray on CLADLINER. Once the product was firmly set, it was smoothed over with a chip brush, hand trowel and damp sponge.
Result / Rainforth says the decision to take a proactive approach to addressing their city’s sanitary sewer collection system will pay off for years to come. 877-708-2523; www.cladliner.com.
Grout system stops high-volume manhole leak
Problem / During a routine sewer line inspection on Tupper Street in the town of Milton, Ontario, cameras found a manhole leaking a substantial amount of groundwater into the sanitary system. After identifying the leak, Peter Knight-Chevalier, president of Rain Drain Restoration, was called to evaluate the manhole and propose a solution for the infiltration issues.
Solution / PARSON SEAL-TITE, part of the manhole rehabilitation product line from Parson Environmental Products, was chosen because of its ability to stop leaks up to 50 gpm. The moisture-insensitive, two-component, fast-reacting hydrophobic polyurethane grout is designed to stop high-volume active leaks in manholes, pump stations, and other wastewater structures. It is packaged in a dual cartridge with a static mixer and is injected at or near the source of the leak, using a manual dual-component caulk gun. The product cures to a dense, rigid mass in approximately 30 seconds and contains no solvents, CFCs or HFCs.
Result / The grout was able to stop the high-volume leak in less than four minutes, resulting in a significant reduction of groundwater in the town’s sanitary sewer system. 800-356-9023; www.parsonenvironmental.com.
Chimney seals prevent I&I in new manholes
Problem / During the construction of a new subdivision near Louisville, Kentucky, the specification on new manholes stated that all had to be vacuum tested after construction. Upon passing the vacuum test, an internal mechanical chimney seal had to be installed to prevent future I&I into the sewer system, thus preventing costly treatment of unnecessary water.
Solution / The project was awarded to Tru Test and included the installation of more than 50 internal manhole seals. Dave Conrad of Tru Test had used Trelleborg Pipe Seals’ DrainFlexRib Manhole Chimney Seals for several years. The solution consists of an EPDM seal, which has a rib design that allows vertical and lateral movement, while still ensuring a watertight seal. The waveband technology creates a more effective seal by concentrating the compressive force of the expansion band, effectively capturing the rubber between the band and the concrete. The chimney seals were installed before the contractor had finished the final asphalt road surfacing. After completion of the road grading, Tru Test went back to check the installation. This was less than two weeks after the manholes had passed the initial vacuum test.
Result / The top retaining band of the Trelleborg DrainFlexRib seal was already performing. It held back water that had leaked through the failed mastic and concrete grouting that the manhole contractor had used to help pass the vacuum test. Without the installation of the chimney seals, the newly installed manholes would already be leaking two weeks after construction. Instead, an immediate impact on I&I was achieved. 800-626-2180; www.trelleborg.com/pipe-seals.
