Connecticut
Connecticut Construction Entrance Detail
Connecticut is named after the Connecticut River which accounts for 70% of the fresh water introduced to the Long Island Sound. The Connecticut River is deeply linked to the early history of the state and presently is the focal point of Connecticut’s major cities. The state’s population is concentrated in the Connecticut River Valley therefore the health and purity of these waters is key in maintaining a clean environment for the residents of Connecticut. The river is the longest in the region with 406 miles of shoreline it collects the stormwater from 11,260 square miles. This vast watershed area makes the river vulnerable to the pollution introduced in the storm water. For the first half of the 20th century industrial and construction pollutants have negatively affected the purity of the river and consequently the health of ecology connected to its waters. The Connecticut River is home to wide variety of freshwater wildlife including rainbow trout, pike, and eels. Eight of the twelve mussel species present in the river are on the endangered list.
The Water Quality Act of 1965 has had a great beneficial impact on the purity of the Connecticut River raising the quality rating and making the river safe for fishing and swimming in most sections. The possibility for improvement is still available and continuing the path of protecting this resource is vital for the health of the residents, economy, and the growth of the state. In order to reduce the pollution introduced to the stormwater of Connecticut the state has implemented the use of NPDES permits to supervise and control the impact of construction sites on the health of the surface waters.
Connecticut DEPT. of Energy and Environmental Protection
The EPA has established the National Pollutant Discharge Elimination System (NPDES) in order to prevent construction and industrial activities from negatively affecting the stormwater system. In Connecticut the NPDES program is administered by the Department of Energy and Environmental Protection (DEEP). The General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities ("Construction Stormwater General Permit") is meant to cover the common cases for construction activities. Contractors seeking coverage under this General Permit are required to create and implement a Stormwater Pollution Control Plan (SWPCP).
The SWPCP document outlines and specifies each potential source of pollution and the techniques which will be used to mitigate and contain the contaminants. The techniques called Best Management Practices or BMPs. On sites without proper BMPs in place, contaminants may leave sites through dust, runoff, heavy erosion areas, and on vehicles exiting construction site. This requirements of the SWPCP are explored in detail on the DEEP’s General Permit for the Discharge of Stormwater Guide section 5(b).
An effective SWPCP plan includes measures to minimize pollutants leaving the construction site and entering the public stormwater system. The goal of a successful Stormwater Pollution Prevention Plan is to create a closed stormwater system within the effected construction zone. These pollutant sources can be contained through proper planning and implementing of proven practices and products such as dust watering and anti-erosion fabrics. The Connecticut DEEP publishes 2002 Connecticut Guidelines for Soil Erosion and Sediment Control to assist contractors and engineers as they plan operations.
Tire Tracked SoilS - Construction Entrance Detail
The most common source of water pollution from construction sites is soil and debris which is tracked onto public roadways. Rain events will carry sediment laden storm water into storm drains which flow directly to waterways. To address this pollution source, the Construction Entrance (CE) BMP is installed on a job site. The Construction Entrance is placed at the entrance and exit points to the job site to mitigate sedimentation and erosion caused by construction vehicles. A variety of options are available to the operator and Plan designer to address this potential pollution source. The 2002 Connecticut Guidelines for Soil Erosion and Sediment Control contains information about common techniques and dimensions of Anti Tracking Pads. Section 5-12 of the 2002 Guide defines a typical construction entrance as a stabilized pad consisting of stone or mud rack located at the ingress egress points of the construction area to mitigate the soil tracked onto public roadways by vehicles exiting the site.
A construction entrance is usually one of the first practices implemented by an operator prior to other construction activities in order to safely bring heavy machinery onto the construction zone. The CE serves both to remove sediment from construction vehicles and to provide a stable surface for the heavily trafficked ingress/egress points. The construction entrance location should be carefully considered when planning the SWCPC in order to allow vehicles to effectively access the entire site during construction and to accommodate the required dimensions for soil tacking prevention. There are several options when designing a stabilized anti-tracking pad and each has its own benefits and maintenance routine.
Street sweeping is required during construction activities for any sediment that escapes onto the roadways. When a construction entrance is installed and properly maintained, the need for street sweeping can be significantly reduced.
Stone Stabilized Pad Construction Entrance
Stone Stabilized Construction Entrance From 2002 Connecticut Guidelines for Soil Erosion and Sediment Control.
A gravel stabilized pad is a traditional construction entrance BMP and consists of pad of stone. The guide recommends using #2 or #3 angular stone at a minimum of 6 inches deep. The stone removes pollutants clinging to a vehicle’s wheels by working between the treads of the tires. The length of a stone stabilized construction entrance is between 50 and 100 feet, while the minimum width is 12 feet with a wide turning radius as needed. Where the construction entrance meets the public roadway, the entrance should be flared in order to accommodate the turning radius of the vehicles. A geotextile fabric must also be laid before the stone to separate the native soil from any pollutants removed by the stone.
The stone stabilized pad will require regular maintenance to mitigate trackout. When aggregate becomes compacted with sediment, the operator must top dress the pad with additional aggregate. When the site is completed, the stone must be excavated and removed before final stabilization.
If the stone construction entrance is not sufficient to prevent the majority of the sediment from being tracked onto the street, operators can add a mud rack or wheel wash to increase effectiveness.
Mud Rack
A mud rack, also called shaker plate or shaker rack, consists of a frame make from angled steel or other reinforced material which shakes and agitates tires to dislodge soil which collects under the frame. The rack is maintained by removing the frame to clean away debris. Similar to the stone stabilized pad, the entrance can be extended as need to prevent debris from tracking out of the construction site.
Wheel Wash Detail
When the stone construction entrance or mud rack does not sufficiently remove sediment from vehicle tires, the entrances can be combined with a wheel wash. The wheel wash station removes sediment from vehicles through a pressure washer. The sediment laden water is intercepted and diverted into a sediment trap or basin where it can settle on-site. This system is highly effective, but requires access to a supply of both water and power.
FODS Trackout Control Mats
FODS Construction Entrance Stormwater BMP Installed at egress point. The FODS Trackout Control Mats provide effective sediment control and last for 10+ years of repeated use.
An modern technique for construction site trackout is the FODS Trackout Control Mat System which provides contractors with an effective and reusable solution for construction trackout. The FODS Trackout System is composed of a set of HDPE mats which are formed into pyramids on the surface. The pyramids deform vehicle tires and allow trapped debris and break loose, in addition, the mats also capture debris at the base of the pyramids where it will not contact vehicle tires. Each mat is 12’ wide and 7’ in the direction of travel and works as a modular system allowing contractors to build to fit the needs of each project.
FODS are both effective and reusable which can lead to significant cost savings over the life of the product. FODS Trackout Control System has been shown to reduce required street sweeping by 59% compared to stone stabilized pads. The portable mats enables contractors to lower costs by reusing the system on multiple entrances on a linear project as well as on multiple projects over the 10+ year product service life.
Installation of a standard 1x4 entrance can be completed in as little as 30 minutes without the use of heavy equipment. Mats can be installed on challenging environments such as steep grades, ungraded soil, and existing concrete and asphalt. Compared to traditional techniques, FODS enables better containment of sediment and while enabling responsive project planning.
FODS are easily maintained by removing sediment when it builds between the pyramids. The mats can be cleaned in a variety of ways. Most commonly contractors use a skid steer with a broom attachment to brush away sediment that builds between the pyramids, but a FODS shovel can also be used to remove debris manually.
When the work is complete the mats can be easily loaded onto a trailer and since there is no gravel to excavate, the remediation required for final stabilization is minimal.
Additional Resources:
DEEP 2002 Connecticut Guidelines for Soil Erosion and Sediment Control
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.