Near the heart of St. Cloud, MN, sits the newly constructed Encore on the Park Apartments, a 154-unit complex close to a 75-acre park.

As with most construction projects, issues occurred that weren’t foreseen. The Encore Apartments’ challenge was a stormwater management system.

Design Tree Engineering of Rogers, MN and Miller Architects and Builders of St. Cloud, MN, were vital in the design and development of a stormwater system that not only met federal stormwater regulations but addressed the problems of limited space and poor soil.

The stormwater system Design Tree and Miller Architects developed was an underground infiltration system that used a sustainable material called tire-derived aggregate (TDA). TDA is made from processed shredded tires, and its properties are ideal for stormwater management systems, roads, retaining wall support, and many other civil engineering projects.

One of the advantages of this manufactured sustainable aggregate is that when compacted in place the void space available to retain and detain water is 50%. This is substantially better compared to other aggregates. TDA’s void volume is three times that of three-inch rock, six to eight times more than expanded shale aggregate and five times that of sand. It is also lightweight, excellent for eliminating frost upheave, and costs a third to half less than other traditional aggregates.

Developing a stormwater management system begins with digging a trench and lining it with geotextile fabric. TDA’s eco-friendly tire shreds are placed in the trench and compacted with heavy equipment, then covered with the geotextile fabric. The system collects and slows down the flow of stormwater from the building and adjacent parking lot.

Residents of Encore on the Park now have an efficient stormwater management system. Plus, they have an environmental bonus with the equivalent of more than 45,000 scrap tires on the job instead of in a landfill. The final phase included four feet of soil on top of the geotextile. The system collects and slows down the flow of stormwater from the building and adjacent parking lot.

Residents of the Encore on the Park now have an efficient stormwater management system. Plus, they have an environmental bonus with the equivalent of more than 45,000 scrap tires on the job instead of in a landfill.