Michigan City Sanitary District retained DLZ for planning, design, bidding, and construction phase services for Sheridan Beach storm sewer systems. Other services included updating an existing Preliminary Engineering Report (PER) and completing a State Revolving Fund (SRF) Application for SRF funding.
DLZ performed a preliminary survey, site visits, and analysis to develop alternative locations for proposed storm sewer and underground stormwater infiltration systems. DLZ discussed alternatives with both, MCSD and contractors, to assess feasibility and constructability as part of the PER update process. A primary goal was to maximize the reduction of inflow into the sanitary (combined) sewer system. DLZ developed a combination of several storm sewer networks to intercept the maximum number of existing inlets in the area. This was done to allow for the future separation of other identified inflow locations (driveway/basement drains, downspouts, sump pumps, etc.)
The final design and construction for the Sheridan Beach sewer installation included
- Over 2,600 feet of 12-inch to 48-inch storm sewer
- 1,900 feet of 8-inch to 18-inch sanitary sewer
- Three (3) underground stormwater infiltration systems providing a total of approximately 15,000 cubic feet of storage volume
Portions of the 30-inch storm sewer were over 20-feet deep in beach-type sands with a moderate to high water table. DLZ coordinated with multiple contractors to develop a trenchless sewer installation specification that allowed the contractor flexibility to use one of several different methods to install the sewer. Pilot tube microtunneling operations constructed the deep sewer.