Henry County, Georgia 7 Manhole Structural Rehabilitation
Project Name: Indian Creek Structural Manhole Rehabilitation
Client: Henry County Water Authority
Location: McDonough, GA
Time Project Took to Complete: 15 days
Technologies Utilized: Euclid V-100 and SprayWall
A community in Georgia was interested in either replacing or structurally rehabilitating seven sanitary sewer manholes of which five were located on a sewer easement while the other 2 were at their operations facility. Due to the high flow and volume of Hydrogen Sulfide (H2S) gas, the structural integrity of the structures was being addressed via the Special Projects budget of the utility.
Upon inspection of these manholes, the depth of the structures varied from 10 feet to 25 feet with all of them being 4 feet in diameter. It was determined that the structures were seeing approximately 75% deterioration of the walls, chimney, and bench areas with severe corrosion to the precast walls due to the incredibly high levels of H2S as well as groundwater infiltration on the deeper structures.
Engineered Spray Solutions partnered with the utility to create a plan and schedule for repairing the structures. This included working together to bypass several of the structures. A chemical grout injection method was used in all areas of infiltration within the structures to completely seal the manholes from groundwater infiltration. After a 5,000-psi water pressure cleaning, proper surface preparation of the concrete surface followed for all areas that were to be structurally lined with SprayWall. Once the surface was completed inspected, the engineered tapered SprayWall system was applied in thicknesses ranging from 735 mils in the base sections with a taper up to 250 mils at the top sections. This varied as each manhole had its own customized design given its unique conditions.
By utilizing SprayWall with a custom thickness design for each structure, a monolithic leak free structural liner was achieved. The community engineering and utilities staff approved Engineered Spray Solutions application; the project was completed in 3 weeks’ worth of construction with a price of $131,000.00. This quick movement and effective design saved the community 339,000 dollars or 72% of the original plan’s estimated cost and at least 6 months’ worth of disruption to the utility’s system thus impacting the residents.