TDA Stormwater Management System Installed At High School
Designing and implementing a safe stormwater infiltration system can be a challenge in limited spaces. That’s what contractors working on the expansion of the parking area at Paynesville Secondary School, in West-Central Minnesota faced.
“The biggest factor was space,” Jeremy Mathiasen from Stantec Engineering said. Mathiasen designed an underground stormwater infiltration gallery to be installed beneath a sidewalk passing through the school’s two parking lots. His design eliminated the need for open storm water ponds, which would have reduced the parking area and created a year-round safety hazard.
Under the path is a unique stormwater management system designed with tire-derived aggregate (TDA). Mathiasen said TDA was the right choice for several reasons.
“Being underground, we were able to maintain more parking area and keep the system centrally located on the project. TDA helped us maintain green space and meet parking requirements,” Mathiasen said. A 330-foot long concrete sidewalk placed over the stormwater management system provides a safe and attractive route through the parking lot, he said.
Cost savings are realized. Alternative water management plans would have been more expensive. The low cost, permanent solution significantly reduced impact to the school’s budget.
TDA performs well. Mathiasen says there is a high void space with lots of room for water. The material is lightweight. It compacts well. It serves multiple purposes and meets multiple civil engineering needs. Maintenance is minimal. There is a clean out system that allows sediment to be flushed out if it builds up, but that isn’t expected to be an issue, he said.
During construction of the parking lot, the existing path was dug down six feet, lined with a geotextile fabric and filled with TDA. Approximately 60,000 tires were used to manufacture the TDA, which was placed over 1,000 cubic yards in the stormwater system.
Voss Plumbing and Heating, Paynesville, installed the TDA in one day, using heavy equipment to compact the material. Once compacted the TDA received a top cover consisting of a combination of geotextile fabric and geogrid. Workers new to the material commented it was like driving on marshmallows, and was much easier to work with than expected.
Water running off of the building and parking lot will collect in the TDA. From there, water will slowly infiltrate into the soil. Should there be a large storm, there is an overflow into an existing storm sewer system.
National studies on TDA show environmental benefits, Mathiasen explained.
“Testing has indicated that the tire shreds and the steel in the shreds help treat nutrients in the water,” he said.
Past and present scientific studies show that TDA is removing chemicals like phosphorus, nitrates, fertilizers, and pesticides from the stormwater, according to TDA Manufacturing, Isanti, MN, manufacturer and supplier of the material.
The company’s CEO Monte Niemi patented the product decades ago and has been a champion of educating the construction and environmental industries on the benefits of using TDA. With more than 350 projects completed, Niemi sees a bright future.
“TDA is an invisible workhorse in civil engineering applications,” Niemi said. Across the country, it’s getting recognition for solving problems in the most cost-effective, environmentally friendly and technically sound ways.”
© Scrap Tire News, December 2020