Wyoming Vehicle Tracking Controls
Home to the timeless beauty of Yellowstone, the nation’s first national park, the state of Wyoming retains a natural beauty that has been long recognized and protected. From the caldera’s wild bison, grizzly bears, and bald eagles, to the pronghorn and sage grouse spread across the plains, the expansive terrain is home to a robust ecosystem. The state’s watersheds flow into Yellowstone Lake and Jackson Lake on the north western region and various reservoirs and rivers throughout the state provide water to the Medicine Bow-Routt and Big Horn National Forests. Wyoming’s Department of Environmental Protection works to protect these water sources and ecology throughout the state.
Wyoming WYPDES Stormwater Permits
The Wyoming Department of Environmental Quality (DEQ) administers the Federal NPDES program through the Wyoming Pollution Discharge Elimination System (WYPDES). The federal ruling prohibits all point source discharges into surface waters except those covered through permit authorization. The Wyoming DEQ issues general stormwater permits to authorize the more common discharges including the Large Construction General Permit (LCGP WYR10-0000), Small Construction General Permit (SCGP), Industrial General Permit (IGP), Municipal Separate Storm Sewer Systems (MS4) Permit, and Mineral Mining and Associated Activities General Permit (SIC 14). Each permit is designed with requirements to maintain surface water quality within the federal and state quality standards.
Construction activities that disturb an area of one acre or greater, but less than five acres can use the SCGP, while construction activities that disturb an area of five acres or more will require the LCGP. Both of these permits are considered “no-application’ permits because the coverage is automatically obtained by following all provisions of the existing general permit.
WYPDES LCGP CONSTRUCTION PERMIT REQUIREMENTS: SWPPP PLAN
To obtain permit authorization under the LCGP, construction operators must submit a Notice of Intent (NOI) along with a Storm Water Pollution Prevention Plan (SWPPP), any applicable fees, and a map which displays access to the site from a public roadway. The SWPPP includes a description of each potential pollution source on the project and specifies which control measures, called Best Management Practices or BMPs, will be used to eliminate or reduce the impact of the pollutants on surface waters.
The Wyoming DEQ provides resources for operators and engineering teams including fact sheets, presentations, and other materials on Storm Water Permitting on the DEQ website.
WYOMING SAGE GROUSE MANAGEMENT REQUIREMENT
As of the 2019 Executive Order 2019-3, operators must determine if their project is within the Sage Grouse Core Area (SGCA), or other areas which are vital to the Sage Grouse habitat. If a project is within a protected area, the Wyoming Game and Fish Department reviews the planned project and issues a Letter of Consistency before stormwater permit authorization is granted. See the Wyoming Game and Fish Management Website for more details.
LGCP APPENDIX C 2.2: VEHICLE TRACKING CONTROL MEASURES
The LGCP states that vehicle tracking of sediment from the site must be minimizes by BMPs which may include aggregate surfacing or alternative measures. The permittee is also responsible to remove any sediment that is deposited onto the public roadway. Sediment removal can be completed by sweeping or scraping or other means which will not wash sediment into nearby storm drains. Operators are required to remove accumulated sediment within 24 hours or less depending.
Vehicle Tracking Control Measures, or Stabilized Construction Entrances, are often the first BMP to be established during land development. Sediment entering the roadway from construction vehicles can pose a hazard to traffic and can easily wash into storm drains which increases maintenance on the drainage system and degrades water quality.
WYDOT Field Guide: VEHICLE TRACKING CONTROL AGGREGATE PADS
The Wyoming DOT includes an example of an aggregate based construction entrance in their published Field Guide. The guide reminds readers that sweeping is a reactive step taken when damage is already done and not to be considered an adequate prevention measure.
A diagram of the example entrance is included in the field guide which shows a 50’ length aggregate tracking pad 9” in depth which is underlaid with a non-woven geotextile fabric to prevent the rocks from sinking into the subgrade. The entrance is shown to be 20’ in width or less if vehicles are confined to to exit lane. The aggregate mentioned is 6” minus rock which is provides a sufficiently rough surface which can be effective are removing sediment from tires.
All BMPs must be maintained throughout the duration of each construction project to ensure they are in functional condition. Aggregate construction entrances must be maintained when the aggregate becomes saturated with sediment or when the rock becomes compared and is no longer created a rough surface. Aggregate construction entrances are maintained by installing an additional layer of aggregate and if needed relining with geo-textile fabric. During weather events maintenance and sweeping may be required more frequently. If the construction entrance is not sufficient to contain the majority of sediment within the job site, additional control measures or alternative control measures must be implemented.
FODS Trackout Control System BMP
The FODS Trackout Control System is a control measure for construction site entrances which is effective and reusable. The system consists of 12’ x 7’ panels have pyramidal structures on the surface. The pyramids work to flex vehicle tires to dislodge sediment and debris and create a void where sediment can collect. The system is typically installed using 4 panels in series (1x4 diagram) to create one 12’ wide exit lane which exiting traffic is directed towards using signs or posts. The FODS trackout control measure can be installed on grade or over asphalt and concrete.
When the voids between the pyramids fill with sediment, the entrance requires maintenance. The system is maintained by removing the sediment using either a FODS shovel which is designed to fit between pyramids or by brushing the mats with a street sweeper or skid steer with a broom attachment. In many cases, the FODS system is proactively cleaned by directing sweepers to brush the mats as part of the routine sweeping schedule
The FODS system is a highly effective and cost efficient solution for mitigating construction site track out. The system has been shown how to reduce required street sweeping by 59% compared to traditional aggregate entrances. The system is portable and reusable which enables operators to relocate the entrance for each phase of the project. The mats are durable and can be reused on multiple projects over the course of their 10+ year service life.
Additional Resources:
Wyoming DEQ Stormwater Permits
Wyoming DEQ Stormwater Permits - Large and Small Construction General Permit