DTE, in collaboration with the City of Lapeer, broke ground in spring of 2016 on 45 megawatts (MW) of new solar generating capacity at two project sites: DeMille Road and Turrill Road. Completed in 2017 by Barton Malow, the project’s construction manager, the array generates enough clean solar energy to power more than 9,000 homes. The DeMille Road project is the largest operating utility-owned photovoltaic solar array east of the Mississippi and the third largest in the country.

SME to provided pavement engineering services that included subgrade stabilization and design recommendations for the construction of the access roadway for the site. The access road was located within an undeveloped agricultural field and spans two miles long. SME identified the existing conditions of subgrade soils at the site, as well as recommendations for soil stabilization to provide a subgrade that will support the proposed pavement system. The proposed roadway was designed to include approximately four inches of aggregate base over a chemically stabilized subgrade.

The local Fire Marshal requested that Barton Malow secure engineering testing and calculations to show the resulting support conditions of the proposed pavement system. SME performed the preliminary evaluation and a subgrade evaluation, and recommended a proposed stabilization mix design along with American Association of State Highway and Transportation Officials (AASHTO) calculations relating to pavement cross section design.

On the Turrill site, construction was well underway; however, the site topography had been rolling with significant overall elevation changes. SME provided stormwater and soil erosion control design services. SME conducted a topographic survey of the 193-acre property, hand collected shallow subsurface borings for evaluation, prepared engineering documents of our recommended design, and provided field verification and materials testing.