Alabama Construction Entrance Pad Detail (CEP)

Alabama's history has significantly shaped America, particularly through its role in the Civil Rights Movement and Huntsville's achievements in space exploration. These milestones provide a foundation for innovation in today’s construction and environmental management practices across the state.

Today, Alabama is experiencing a manufacturing renaissance, with automakers such as Toyota, Mercedes-Benz, Honda, and Hyundai operating large production facilities across the state. These companies emphasize environmental stewardship and work to protect Alabama’s natural features, including Noccalula Falls, DeSoto Caverns, and the Gulf Coast shoreline at Gulf Shores. The state's water resources are managed through state and federal stormwater permit programs to protect inland waterways and coastal regions.

Alabama NPDES Stormwater Permits

In the state of Alabama, the Alabama Department of Environmental Management (ADEM) administers the National Pollutant Discharge Elimination System (NPDES) under authority delegated by the U.S. Environmental Protection Agency pursuant to the Clean Water Act. ADEM oversees stormwater permitting for construction, industrial, and municipal activities and is responsible for reviewing Construction Best Management Practices Plans (CBMPPs), issuing permits, and enforcing compliance to protect water quality.

NPDES permit coverage is required for construction, industrial, and municipal operations that discharge stormwater. ADEM manages permitting through the Alabama Environmental Permitting and Compliance System (AEPACS), which allows operators to submit Notices of Intent (NOIs), applications, supporting documentation, and reports electronically.

ALR100000 NPDES Construction Permit Requirements: CBMPP Plan and NOI

Contractors conducting land-disturbing activities of one acre or more must obtain NPDES permit coverage before beginning construction. Many projects are eligible for coverage under the General NPDES Construction Permit No. ALR100000. To obtain coverage, operators must submit a Notice of Intent (NOI) along with a Construction Best Management Practices Plan (CBMPP).

The CBMPP identifies anticipated sources of sedimentation and pollution and outlines Best Management Practices (BMPs) to minimize impacts on receiving waters. Individual permits may be required when coverage under the General Permit is not applicable.

ADEM provides supporting resources for compliance, including a Field Guide of Best Management Practices for contractors, standard CAD drawings for engineers developing erosion and sediment control plans, and inspection tools used by ADEM staff to verify permit compliance during construction.

Construction Exit Pad (CEP-1) Gravel Construction Exit

The ADEM Handbook includes Site Preparation BMPs implemented at the start of construction. One of these BMPs is the Construction Exit Pad (CEP-1 Gravel Construction Exit), which is designed to remove sediment and debris from construction vehicle tires before vehicles exit onto public roadways. Preventing sediment from reaching paved roads reduces the risk of sediment entering storm drains and surface waters.

ADEM defines a Construction Exit Pad as a stone base pad or manufactured product that provides a buffer area to remove mud and caked soil from vehicle tires at ingress and egress points connecting to public roads. When aggregate is used, the handbook specifies ALDOT coarse aggregate gradation No. 1. Construction Exit Pads must be installed at all locations where construction traffic exits onto active public roadways.

The handbook provides recommended entrance dimensions that may be adjusted based on site conditions and traffic volume. Typical dimensions are approximately 50 feet in length, 20 feet in width, and a minimum depth of 6 inches. Where soils are weak or become unstable when saturated, a nonwoven geotextile fabric is recommended beneath the entrance to support vehicle loads. Runoff from the stabilized entrance must be directed back onto the site or conveyed to a sediment basin or trap.

If sediment is deposited on adjacent roadways, contractors are required to remove it by sweeping or scraping, typically daily. Following rainfall or extended use, entrances require ongoing maintenance. Aggregate entrances are maintained by adding clean stone and reworking the surface to restore roughness and effectiveness.

FODS Trackout Control Mats

The FODS Trackout Control Mat system, also known as the 1100TCM system, is designed to clean construction vehicle tires as they exit the jobsite onto public roadways. The system consists of modular HDPE mats formed into pyramid-shaped surfaces that promote tire deformation and dislodge mud and sediment from tire treads. Dislodged material collects between the pyramids, away from contact with subsequent vehicles.

The mats can retain approximately 2.5 inches of sediment before maintenance is required and can be cleaned quickly to restore performance. FODS systems have demonstrated reductions in street sweeping requirements and can be reused for 10 years or more, thereby reducing long-term construction entrance costs.

FODS Trackout Control Mats have been added to the Alabama Department of Transportation Approved Products List as an acceptable alternative to traditional rock-stabilized construction entrances. Their portability and reusability make them particularly well-suited for phased highway projects, where entrances may need to be relocated multiple times. Because the system does not introduce aggregate, it reduces the risk of loose rock entering active traffic lanes.

ALDOT I-59/20 (5920) Bridge Project

The I-59/20 (commonly referred to as the “5920 Project”) in Birmingham is one of the largest highway reconstruction projects undertaken in Alabama. The project included adding travel lanes, widening shoulders, and improving interchange access to enhance safety and reduce congestion along a corridor carrying tens of thousands of vehicles daily.

Phased highway and bridge projects benefit from the FODS system's portability. Construction entrances can be relocated as work progresses and reinstalled in as little as 30 minutes, supporting efficient site operations while maintaining stormwater compliance.