The National Pollutant Discharge Elimination System (NPDES) is an EPA initiative to keep our waters clean, by controlling contaminants at their source. To prevent pollution and debris from flowing into our rivers, lakes and oceans, NPDES regulations require municipalities, factories and construction sites “to prevent stormwater runoff from washing harmful pollutants into local surface waters.”
Adhering to this regulation is particularly tricky on construction sites, which tend to get muddy. If trucks leave the site with their tires covered in mud–which may contain chemicals and other pollutants from construction processes–and track that mud all over the surrounding roads, they have violated the regulations, and can have their NPDES permit yanked.
This is why you often see construction site entrances paved with gravel or even sheets of plywood; they serve as “doormats” for the muddy truck tires, cleaning them off before they take to the roads. But the gravel and plywood are single-use, single-site solutions; they cannot easily be rinsed off and taken to the next jobsite. Thus using them is wasteful.
To solve this, a Colorado-based company called FODS (Foreign Object Debris System) has designed their Trackout Control Mats, “the only durable, cost-saving, and environmentally friendly reusable construction entrance mat solution available,” they write. “Our proprietary mat design works effectively to remove mud and sediment from your vehicle tires without damaging the tire or the ground’s surface.”
The mats are 7’ x 12’ sheets of HDPE with pyramids molded into the top.
“These alternating rows of pyramids are specifically engineered to open a tire’s lugs as vehicles pass over, causing the mud to loosen and fall out into the base of each mat. The mud collects at the base of the mat preventing it from reaching the street. It will not come in contact with the tires of subsequent vehicles, preventing mud, debris, and other pollutants from leaving a worksite and entering roadways or stormwater systems.”
Once transported to site, the mats are arranged into a roadway and bolted together with steel hardware.
After the job’s done, the mats can be cleaned off with a streetsweeper, a broom attachment on a skid steer or even a pressure washer.
The ultra-durable mats–which weigh 430 pounds each and can support 250,000 pounds on a single sheet–can be used over and over again.
At the end of their life, the HDPE mats are fully recyclable.
I just wish someone made a doormat for shoes that’s this effective. It’s muddy season here on the farm, and I’ve yet to find a doormat that can keep us from tracking mud into the house.
https://www.core77.com/posts/105693/Smart-Design-Sustainable-Doormats-for-Construction-Truck-Tires-to-Comply-with-Environmental-Regulations