Back in the middle of the summer we took over a job that was in the middle of the review process. iRoy Sport and Fitness is a gym located in East Norriton Township owned by Yori Adegunwa. Taking over a job from another engineer is always a challenge, and on top of that, the new site for iRoy has provided us with some interesting engineering challenges.
The proposed gym will be located along Germantown Pike in Lower Providence Township. Existing conditions at the proposed site include a rundown bridal shop, a few deteriorating buildings, a ton of overgrown vegetation, and some dying trees. It’s quite an eye sore.
The new location is a little over 4 acres and has a grade change of about 32 feet across the site. Finished floor elevations, retaining wall heights, stormwater drainage patterns, and driveway slopes, are all factors that we need to consider during the design phase to balance cuts and fills. Two retaining walls and a steep hill in the front of the building had to be incorporated into the design to make the layout work.
Shallow weathered rock and bedrock were encountered throughout the site during geotechnical investigations. Infiltration was almost nonexistent during testing. How are you supposed to satisfy Township and County Conservation District infiltration requirements if your soils won’t let you? Thanks to the newly released managed release concept (MRC) (https://www.dlhowell.com/blog/pa-dep-releases-guidance-for-managed-release-concept/) you can now achieve the requirement without actually infiltrating. This may seem like an easy fix, but you will most likely need a waiver from the Township to do this and need to do extensive infiltration testing to prove there are no other options.
For this project, we had to design an MRC system, which is more complicated than it might seem. Although there is no “infiltration volume,” there is a volume that needs to pass through water quality features and a volume that needs to pass through the small “slow-release” orifice. Discharge rates must be below a certain value, but you also need to make sure the system will fully dewater within a certain time period. It’s a balancing act to make sure the discharge rate is slow enough, but also fast enough.
Despite some struggling with the new MRC design and the large grade change across the site, the iRoy Sport and Fitness job has been an interesting project to work on. We here at DL Howell are always ready to take on a challenge!