A problem that has become more and more troublesome to stormwater professionals and contractors is the use of traditional rock trackout control measures in non-traditional conditions.
Such a situation presented itself at the Argo substation in the heart of Denver, CO. Substations take the electricity from power plants and transmission lines, transform it from high voltage to lower voltage, and distribute it to consumers. Substations are unique because of the confined work area, the nature of the components, and the need to pack a lot of apparatuses in a small area. The Argo substation presented these very problems. The subcontractor working in the area with extremely large drilling equipment and heavy machinery approached Evergreen Caissons, based in Commerce City, CO, which ultimately was responsible for keeping the streets free of rocks and sediment. Evergreen Caissons is a contractor specializing in electrical transmission line construction.
At first, the traditional method of using rocks to prevent trackout was used. “The rocks kept migrating into the streets and required constant sweeping and maintenance,” says Jeff Mata, project supervisor for Evergreen Caissons. “We searched for replacements to rock.”
He described the problem as maddening. “After trying popular alternatives to rock—paper mats, steel rumble plates, and rumble strips—we were still faced with constant sweeping and maintenance. After seeing a large rubber blocked mat on a CDOT [Colorado Department of Transportation] project, and with a little searching, we were able to contact the manufacture, Tracking Pads LLC, who happened to be in our backyard and was happy to help.”
What Mata had seen alongside the highway was a test CDOT was conducting to determine if a new APL or “approved product list” category should be added to a list of erosion control products. The state’s APL includes several categories—for example, under the erosion control category you might find the subcategory for slope stabilization. There are also technical diagrams showing the appropriate BMPs within the subcategory, and a list of APL vendors who carry the products. However, CDOT and other agencies have no category for anything except rock trackout pads. Project engineers, however, can request to use a product that is not on the list, such as Tracking Pads, which have been requested many times.
CDOT set out to create a subcategory to standard rock trackout control titled “pre-manufactured entrances.” The subcategory must still be approved by several entities, including EPA. In the interim, Tracking Pads are considered an approved product.
Tracking Pads LLC, the manufacturer of the flexible, heavy-duty rubber mat, was pleased to assist Evergreen Caissons solve its problem. Tracking Pads supplied a construction entrance mat for the duration of the project. Because the mat is flexible and extremely durable, tracked machinery and large drill rigs can turn on the mat and not disturb the soil. And the yellow marking clearly defines the entrance to a most hazardous environment.
The mat has been tested with a 78,000-pound steel-tracked excavator spinning on top of it with scarcely noticeable damage. (See the video at www.trackingpads.com.) Each 12-foot-square section weighs 2,400 pounds and can be folded or rolled up, making the mat easy to transport from site to site. Most entrances routinely use a minimum of two 12-foot square sections and clip-on flares for large turning radiuses onto the roadway. The large voids in the mat trap material and substantially reduce sediment and larger material leaving the site and potentially damaging vehicles, putting workers at risk.
Jerry Bouchard, manufacture and owner of Tracking Pads LLC, says, “Local, state, and federal agencies are beginning to understand the need for and to implement procedures to specify pre-manufactured entrances. Up to now, the options for alternatives to rock have been nearly nonexistent.”
There has been much interest from other state, federal, and city governments who see the need for a change from rocks to a more appropriate and environmentally friendly product. Tracking Pads understood that eight years ago and set out to design a trackout device that takes the environmental footprint of hauling rock from the pit to the site into consideration, that uses a recyclable material, and that clearly marks the entrance to a project, creating fewer construction and road liabilities. The product reduces the amount of sediment and all but eliminates fractured stone from migrating offsite.
