Lining system helps repair leaking lift stations

Problem: Three lift stations needed rehabilitation for a variety of reasons in Albert Lea, Minnesota. Water was penetrating through the mortar joints and concrete blocks causing their coatings to delaminate, allowing inflow and infiltration. The lift stations also had groundwater seepage into the structures, which was contaminating electrical equipment. 

Solution: These dry side access hatchway lift stations built of concrete blocks required a system that would plug the leaks, as well as reseal and protect the surface from future damage. Floorcoat Midwest, one of CLADLINER’s sales representatives recommended CLADSTOP 3 to plug the leaks and CLADLINER for sealing and resurfacing. Contractor Fieldstone Services began surface preparation to remove all debris and foreign material. CLADSTOP 3 was then mixed in small amounts and applied to the actively leaking areas. The remaining surfaces were sprayed with water from a small, hand-held pump sprayer to provide a surface-saturated dry substrate. Lastly, CLADLINER was mixed and hand-troweled at 1/4 inch.

Result: Two weeks after the application, a follow-up inspection confirmed the success of CLADSTOP 3 in plugging the leaks and ultimately stopping the I&I. The city’s proactive rehabilitation measures will ultimately improve the efficiency of the lift stations and will prevent any further cracking or deterioration from taking place. 877-708-2523; www.cladliner.com.

Epoxy allows company to construct full manholes in-house

Problem: In 2017, the city of Edmonton, Alberta, had several projects to install new manholes and replace old nonrepairable manholes.

Solution: The projects were awarded to concrete manufacturer LafargeHolcim. Instead of the labor-intensive process of installing manholes and lining them in the field, they lined manhole rings with one-step 3-gallon kits of Neopoxy International NPR-5305 Epoxy at their manufacturing facility. After installation, gaps between rings were filled with the same product.

Result: 

The company installed 80 manholes using concrete manhole rings lined with NPR-5305 epoxy resin. This approach resulted in less traffic disruption and improved lining quality, and it made the process faster and more efficient, thus reducing construction cost and time. 510-782-1290; www.neopoxy.us.

Headworks influent channels rehabilitated with liner

Problem: Recently, Jacksonville Electric Authority completed a major upgrade to its Mandarin Water Reclamation Facility. Part of the scope of the project was to rehabilitate the headworks concrete influent channels. As is typical with treatment plant headworks structures, hydrogen sulfide concentrations are some of the highest in the entire waste collections system, and JEA was concerned about concrete deterioration. 

Solution: Considering this and the length of time the structures had been in service, they decided to include all the concrete channel surfaces for rehabilitation — roughly 11,000 square feet. Concrete Conservation, a SpectraShield Liner Systems applicator since 1993, was awarded a subcontract for installing the lining system in the concrete channels. As with any large-scale sewer construction project, time is always of concern, particularly in this case with the length of time and cost to bypass 7.5 mgd.

Result: Using the SpectraShield Liner Systems process, a multilayered liner system that has ease of installation and fast curing times, they were able to mobilize in and out of the work site based on the contractor’s scheduling needs and completed the 11,000 square feet of lining in January and February of 2017. 800-284-2030; www.spectrashield.com.

Lining system used to rehabilitate force main

Problem: A 2-mile 27-inch force main that carries sanitary flow from a major pump station in Towson, Maryland, was incredibly deteriorated. The pump station hammer pressure produces extreme air and water pressures at the head of the flow that had led to the complete structural failure of several brick structure outfall manholes and ultimately caused the surrounding earth to enter these structures producing major sinkholes in the area. 

Solution: The solution required trenchless rehabilitation technologies that address two priorities — providing a verified structural design for lining thickness based on third-party verified physical strengths, as well as the ASTM F1216 standard, and the capability for immediate reinstatement of the sanitary flow to the structure. Bypass of this force main flow was not feasible and only a two-hour shutdown was allowed at the pump station. Infrastructure rehabilitation contractor Abel Recon used the SprayWall polyurethane lining system from Sprayroq since the contractor and product were able to meet and exceed the requirements for this project.

Result: The contractor was successful in meeting the tough demands of the project while providing a long-term, verifiable, structural solution in an extremely short time window. The manholes are expected to service this densely populated area for many decades. 800-634-0504; www.sprayroq.com.

Riser system keeps manhole castings and lids in place

Problem: Twenty-nine manhole riser installations were placed in the roadways of Cumming, Georgia. Due to the installations degrading quickly during normal everyday traffic, the manhole casting/lids were moving and getting displaced, which not only compromised ride quality, but also resulted in debris falling into the sewer collection system.

Solution: James Waite Inc. was called in to assess the situation, and the decision was made to remove the grade rings from the 29 manholes and replace them using the Whirlygig Manhole Riser System. Once in place, the riser/collar forms were trimmed to finished height, during which the slope of the roadway is automatically reconciled. After pouring the concrete collar, the result is a monolithic structure impervious to corrosive elements.

Result: Traffic flow across a planar surface was safely restored in short order, and a smooth ride was ensured over the lifetime of the installation. 800-307-4263; www.wgig.us.