Alabama
Alabama Construction Entrance Pad Detail (CEP)
The history of Alabama involves many historic events which have shaped the American story. From Rosa Parks’ protest against Montgomery’s segregation laws to the march at Selma for universal suffrage, the state was the battleground for the Civil Rights Movement. Alabama also led the the country’s space exploration building the first American satellite in Huntsville. This success in turn led to the establishment of NASA’s Marshall Space Flight Center which was tasked with building rockets for the Saturn V during the historic Apollo missions. The progress and achievements that began here were celebrated across the country.
Today, Alabama is enjoying a manufacturing renaissance with automobile manufacturers such as Toyota, Mercedes, Honda, and Hyundai building state-of-the-art manufacturing facilities. These companies are on the forefront of best environmental practices and work to protect the timeless natural features including the beautiful Noccalula Falls, DeSoto Caverns and Gulf Shores Public Beach. The water resources of the state are carefully managed through the stormwater permit program to preserve the inland and coastal regions.
Alabama NPDES Stormwater Permits
In the state of Alabama, the Department of Environmental Management (ADEM) administers the National Pollution Discharge Elimination System (NPDES) established in the Clean Water Act. This department is tasked with reviewing Construction Best Management Practices Plans (CBMPP), issuing permits and ensuring that operators are following best practices to maintain water quality during construction, industrial and other activities. NPDES Permit coverage is required for construction, industrial and municipal operations. The department has created an electronic system, called the Alabama Environmental Permitting and Compliance System (AEPACS), which allows operators to apply for permits and submit a Notice Of Intent (NOI), application, supporting documents, or reports through the online portal.
ALR100000 NPDES Construction Permit Requirements: CBMPP Plan & NOI
Contractors who are conducting land disturbing activities that are one acre or greater must obtain permit coverage before beginning operations. For many construction projects, operators can obtain permit coverage through the General NPDES Permit No. ALR100000. The operators must submit a Notice of Intent (NOI) as well as a Construction Best Management Practices Plan (CBMPP) which identifies sources of sedimentation and pollution which will exist on the project. In addition, the CBMPP includes a list of techniques and Best Management Practices (BMPs) which will be implemented to contain or mitigate any potential damages from the construction activities. Individual permits are issued when coverage under the General NPDES Permit No. ALR100000 is not possible.
ADEM creates resources including a Field Guide of Best Management Practices (BMPs) for contractors who are operating the site, CAD Drawings for engineers as they plan their erosion control strategy, and an app for inspectors who will be visiting the projects on a regular basis to ensure compliance with the permit requirements.
ALDOT Stabilized Construction Entrance
Gravel Construction Exit CEP-1 example. Common dimensions are 50’ x 20’ with a minimum of 6” in depth.
The ADEM Handbook includes Site Preparation BMPs which are implemented at the start of a project. The Handbook includes a description of a Construction Exit Pad or CEP-1 Gravel Construction Exit which is used to capture sediment and debris from construction vehicle tires to prevent deposition onto roadways where it can be washed down a storm drain. The ADEM Handbook description of a Construction Exit Pad (CEP) which is composed of a stone base pad or manufactured product which will provide a buffer area to remove mud and caked soil from the tires of construction vehicles before they exit onto public roads. If stone is used, the aggregate should be ALDOT coarse aggregate gradation No. 1. The Construction Exit Pad is designed to be installed at points of ingress and egress onto active public roadways.
The handbook provides guidelines on entrance dimensions which may need to be increased or decreased depending on soil conditions and traffic volume. Standard dimensions are 50’ in length, 20’ in width and a minimum of 6” in depth. If the soil conditions become unstable when saturated with water, a non-woven geotextile fabric should be installed below the entrance to support the weight of exiting vehicles. In addition, runoff from the Stabilized Construction Entrance must flow back towards the job site or diverted to a basin or sediment trap.
If sediment is deposited or tracked onto the street, contractors must clean the road by sweeping daily. After rain events or continued use, entrances will require maintenance to ensure they continue to contain sediment. Rock entrance are maintained by adding more crushed aggregate to the pad and by mixing the rock to increase roughness and restore effectiveness.
Construction Exit with Wash Rack (CEP-2) dimensions. The Washing Facility is commonly installed in-series with a Gravel Construction Exit (CEP-1).
If the sediment is not sufficiently contained on site, contractors can opt to install a CEP-2 Construction Exit with Wash Rack. The washing facility is installed in-line with the Gravel Construction Exit and is installed such that the drainage is contained in a sediment basin. This technique is installed when necessary to prevent caked mud and soil from being transported to public streets. The washing facility should be constructed of a durable material which will not degrade during heavy use.
The ALDOT standards for Stabilized Construction Entrance (ESC-502) provides similar specifications to the ADEM Handbook. The ESC-502 also mentions that rock must be ALDOT Size #1 to prevent smaller rocks from tracking off the project. The nominal size specified in the standard is 15’ wide by 50’ long unless otherwise shown in the the plans. If the site is expected to have high volume of traffic exiting the site, a wider entrance may be suitable.
ALDOT also approves manufactured construction entrances for use. The manufactured entrances replace the Gravel Construction Exit and reduce the risk of rock fragments from from being tracked onto active roadways.
FODS Manufactured Construction Entrances
FODS Trackout Control Mats are an effective, reusable system to minimize mud tracking from construction vehicle tires. The system is portable and can be relocated as needed during each project phase. FODS Mats are durable and have a 10+ year service life.
FODS Trackout Control Mats/1100TCM system is designed to clean construction vehicle tires as they exit the jobsite onto public roadways. The mats consist of a single layer of HDPE material which is formed into pyramids on the surface. This unique design allows for maximum tire deformation which allows mud and sediment to fall off the tires. The construction vehicle tire treads are opened during the deformation allowing stuck debris to be dislodged. The mats are able to collect 2.5 inches of sediment at the base of the pyramids before coming into contact with vehicle tires. The mats are easily cleaned to restore to effective functionality. FODS have been demonstrated to reduce street sweeping and contractors are able to reuse the system for over 10 years enabling lower costs per job.
FODS Approved For Use By Alabama DOT
Alabama Materials, Sources and Devices with Special Acceptance Requirements Manual (Qualified Products List).
FODS have been added to the Alabama DOT Approved Products List for use as a replacement for traditional rock stabilized construction entrances. Because the FODS Trackout Control System is both portable and reusable, highway projects in particular can benefit from reductions in cost throughout each phase of the project. The system does not introduce rock to the site entrance locations resulting in less risk of aggregate entering the active lanes which can cause hazards to drivers. In addition, the FODS entrance can be installed and relocated using a single delivery vehicle which reduces construction vehicle congestion on the highway.
AlDOT 5920 Bridge Project
Overview of the renovated 59/20 Bridge Junction.
The $750 million 5920 Bridge Project is currently the largest highway construction in Alabama history. The renovations on the major Birmingham intersection included additional lanes, wider shoulders, and increased access for emergency vehicles. These changes all result in major reductions in traffic congestion to the highway which carries up to 80,000 vehicles every day.
Phased projects like highway and bridge construction benefit from the portable nature of the FODS system. The construction entrance can be relocated throughout the project as needed and reinstalled in as little as 30 minutes.
Additional Resources
ADEM Construction Stormwater Resources
ADEM Municipal Stormwater Resources
ADEM Industrial Stormwater Resources
ADEM BMP Handbook: Erosion Control, Sediment Control and Stormwater Management (Chapter 4)
ALDOT Standards (Stabilized Construction Entrance - ESC-502)
Submittal Package
Install Guide, Drawings and Specs.
MaxGen Energy Services, a nationwide service provider for clean energy infrastructure, provides preventative and corrective maintenance for solar farms, as well as immediate responses during emergencies. Learn how MaxGen Energy Services uses FODS to tackle critical solar farm service jobs and remain compliant with Storm Water Pollution Prevention Plans.