- Company: HRP Construction Inc.
- Industry: Water/Wastewater
- Location: Nappanee, Indiana
- Expected Completion Date: February 2018
Access to clean water and adequate sanitation is not readily available throughout the world. In America, we are fortunate to enjoy these facilities, but this has not always been the case, and we still have work to do. In times past, wastewater treatment as we know it did not exist. Wastewater was commonly discharged into ditches, streams, and rivers. Along with the growth urban centers over the last two couple of centuries in America, so too has grown the volume of wastewater being discharged. Throughout much of the twentieth century, wastewater plants were constructed to treat our sanitary wastewater. However; the way many of our sanitary sewer systems were constructed allows, even to this day, for combined storm water and wastewater to overflow into our ditches, streams, and rivers. Over the last two to three decades, focus in the wastewater industry has turned to reducing or treating these combined sewer overflows through the design and construction of Long Term Control Plans. We have been contracted by the City of Nappanee, Indiana to build a Combined Sewer Overflow sewer over 5,800 lineal feet of transport sewer ranging from 48 inch to 66 inch diameter pipe at an average depth of 20 feet in not the best of soil and groundwater conditions. The collected combined sewage flow is being transported to a new storage facility at the Nappanee WWTP to allow for treatment of this wastewater. The work includes ten crossings of the local Berlin Ditch with new Combined Sewer Overflow structures placed on the opposite side of the ditch from the transport sewer. As part of the project there is 1700 feet of new 15 inch sanitary sewer. Work includes relocated water main, restoration of a park, asphalt and landscaping. The work will greatly reduce the volume of combined sewer overflows to the local waterway.
What impact does this project have on America?
This project has a huge impact on residents of the CIty of Nappanee, surrounding communities, America and the natural wildlife by preventing as much combined sewer overflow as possible from entering the local Berlin Ditch. The transport sewer is designed to store flow from the City of Nappanee’s collection sewers and then, by way of our project, transport that sewer flow to the storage tank at the WWTP for treatment. The residents in America should care because the sewer is being treated before entering America’s waterways. This prevents disease and contamination of the waterway.
What interesting obstacles or unusual circumstances did you overcome to complete the project?
This project has presented many challenges to HRP Construction. The soil conditions are a huge challenge to our project team. The soils vary from clay, silts and sands that are trapping ground water at various depths. We have had to hire Dewind Dewatering to assist with the removal of ground water. We have used deep wells, well points, localized sumping and even installing a sock pipe at depths of 25 feet to collect ground water before entering our trench. The ditch crossings require the project team to build temporary bridges with large diameter pipe to maintain flow of the Berlin Ditch. The size of the structures are as large as 144 inches in diameter. That is a 12 feet in diameter concrete structure being installed at depths of 20 feet plus.
What dangers and risks did you encounter, and describe any extraordinary methods used to keep workers safe?
Being extremely deep installing the 66″ through 48″ sanitary sewer we have to stack boxes in order to provide a safe working environment for the workers. The boxes are 10 feet by 28 feet and 10 feet by 24 feet in size. We utilize steel sheets that are 10 feet by 20 feet in size to provide extra protection. Utilizing the stacked boxes and sheets we are able to keep bad soils from entering the excavation. Working in wet and poor soil conditions require extra time and care in order to provide the safe work environment. The work area is tight in nature and we have several trucks being loaded with bad soils and unloaded with good, clean soils for placing back in the excavation.
How did you leverage new technologies to work faster and reduce waste?
HRP Construction utilizes the large excavators, loaders, trench boxes and shields, pipe lasers, joint testers and modern dewatering technology to create a safe, efficient and productive worksite. With multiple members on the crew we are able to keep excavation and backfill (placement of soils back into the excavation) localized with minimum impact to the surrounding areas. Keeping the work area efficient increases our odds of wasting material used to place back in the excavation. We utilize laborers to prepare the pipe and manholes ahead of time to reduce lost time and waste. There is a whole team of people from various subcontractors, suppliers and at our office working on this project for the City of Nappanee. GPS control will be used to restore the site to original conditions quickly and efficiently. Less staking equals less labor and higher production in the field.