Kansas Construction Entrance And Wheel Wash BMP

Kansas Department of Health and Environment (KDHE) Stormwater Permits

The federal Clean Water Act of 1972 was established to improve the quality of the nation's surface waters. The Act established the National Pollution Discharge Elimination System (NPDES) permit program, which regulates water discharges from construction, industrial, and municipal activities. Construction projects that disturb an area of land equal to or greater than one acre (or are part of a larger common plan that disturbs one acre or more)must obtain stormwater permit coverage.

In Kansas, the Department of Health and Environment (KDHE) administers the NPDES permit program by reviewing permit applications, issuing permits to site operators, and enforcing the permit requirements. Permit authorizations allow operators to discharge water in accordance with the permit requirements. Many construction operations can obtain permit coverage under the KDHE's Construction Stormwater General Permit S-MCST-2208-1 (Federal Permit No. KSR100000). To obtain permit coverage, operators will submit a Notice of Intent through KEIMS and develop and implement a Stormwater Pollution Prevention Plan (SWPPP), referred to by KDHE as an "SWP2 Plan," to guide BMP implementation and the mitigation practices used throughout the project.

The SWPPP includes an outline of all potential sources of pollution on the site. In addition, the plan will describe the techniques and processes that will be used to mitigate or contain these pollutants on the job site. The methods are referred to as Best Management Practices (BMPs) and can include structures, practices, and procedures.

FODS Trackout Control Mat Reusable Construction Entrance David Booth Memorial Stadium Lawrence Kansas .jpeg

Construction Entrance BMPs

The most common type of water pollutant is sediment, which can raise water temperatures and reduce oxygen levels. During construction activities, disturbed soils are at risk of rapid erosion, which can lead to significant sedimentation in water sources. Sediment and erosion control BMPs are implemented to contain sediment within the job site and stabilize disturbed areas to reduce erosion.

The Construction Entrance BMP is one of the first structures to be installed at a job site and must be constructed before grading, clearing, and excavation can begin. The purpose of a Construction Entrance is to reduce off-site sediment tracking from construction vehicles onto public roadways, where deposited sediment can enter storm drains. In addition to removing sediment from vehicle tires, the entrance area should include a ridge or be graded to provide drainage back to the site, preventing sediment-laden runoff from entering the roadway. Various techniques are available and can be combined to increase effectiveness.

For this BMP to effectively contain sediment from construction vehicles, Construction Entrances should be installed consistently at every egress point on the job site. In addition, street sweeping or vacuuming should be promptly conducted to capture any sediment and debris deposited on public roadways. In addition, regular inspections and maintenance should be undertaken to ensure the entrance is in good condition.

The General Permit states that "off-site sediment tracking should be minimized by using wheel washing facilities or an appropriately designed washing facility, designed construction entrance and exit"; however, further guidance is often provided by the local permit issuing authority. For example, in the Kansas City metro, some local jurisdictions reference KC-APWA / regional erosion control standard details for BMP design.

Aggregate Construction Entrance

An aggregate construction entrance is a traditional design that uses a pad of coarse rock to stabilize the site exit. The KC-AWPA specifications include a design for an aggregate construction entrance that uses 2" -3" coarse aggregate installed over a Non-Woven Geotextile filter fabric. The filter fabric prevents sediment from seeping from the underlying substrate into the aggregate layer. In this design, the dimensions of the pad are recommended at 50' minimum length and 20' minimum width with a wide turn radius where the aggregate meets the roadway.

During construction, the aggregate pad will become compacted and saturated with sediment, reducing its effectiveness. Once the entrance no longer contains the majority of the sediment on the job site, maintenance will be needed to restore it. An aggregate construction exit is maintained by mixing the stone or top dressing with additional rock. In addition to a regular inspection schedule, entrances should be inspected after rain events, as they can quickly become saturated with sediment.

If the aggregate construction entrance is not sufficient to mitigate sediment tracking, additional or alternative BMPs should be used.

FODS Trackout Control Mat Reusable Construction Entrance David Booth Memorial Stadium Lawrence Kansas

Steel Rumble Plates

The KC-AWPA aggregate construction entrance standards include an optional rumble plate or shaker plate. The system is typically constructed of a steel structure with raised ridges. Some shaker plate styles are raised to create a void below the plates. The ridges are designed to agitate and shake vehicle tires as they exit over the pad. Rumble plates are commonly used in conjunction with an aggregate pad and are placed in the center of the aggregate to supplement the cleaning process.

When sediment fills the voids between the ridges, the plates can be cleaned to restore performance. In raised systems, the plates must be removed to excavate the void below.

Wheel Wash Construction Entrance BMP

Wheel Wash systems use pressurized water to spray mud and sediment from vehicles' tires. A wheel wash station consists of a wash rack and a pressurized water system. A shaker plate or concrete slab can be used as a wash rack. Wheel wash sprayers can be manually operated or automated. When installing a wheel wash station, all wash water must be diverted to a sediment basin or sediment trap to prevent sediment-laden water from entering the roadway.

FODS Trackout Control System

The FODS Trackout Control System is a modern construction entrance BMP designed to remove sediment from vehicle tires and minimize off-site tracking effectively. The system is durable and reusable, allowing contractors to reduce costs. The system consists of modular 12' x 7' HDPE mats, which are formed into pyramids on the surface. The pyramids dislodge sediment and debris by flexing vehicle tires, opening the tread lugs. Compared to traditional aggregate-style entrances, FODS has been shown to reduce street sweeping by 59% at high-traffic-volume sites.

The FODS system can be installed on a variety of substrates, including dirt, concrete, or asphalt. The mats are designed to be used as a standalone system without aggregate, which can eliminate the risk of loose rock entering the roadway or becoming lodged in dual-tire vehicles.

The system can hold 2.5" of sediment between the pyramids before maintenance is required. Maintenance is commonly conducted with a skid steer equipped with a broom attachment or a street sweeper equipped with an adjustable brush. In many cases, entrance maintenance can be performed as part of the regular street sweeping schedule.