Construction Site Access BMP Guide
Understanding Erosion & Sediment Control Site Access BMPs
Rock Construction Entrance
A rock construction entrance should be installed wherever it is anticipated that construction traffic will exit the project site onto any roadway, public or private. Access to the site should be limited to the stabilized construction entrance(s).
A geotextile underlayment should be placed over the existing ground prior to placing the stone. At a minimum, rock construction entrances should be constructed to the dimensions shown on Standard Construction Detail #3-1. Where site conditions warrant, it may be necessary to extend the length or width of the rock to ensure the effectiveness of the entrance. Wherever access to the site is across a roadside ditch, stream channel, natural drainage course, etc., a suitable means of conveying the flow past the entrance (e.g. a properly sized culvert pipe) should be provided. For such installations, a mountable berm is recommended to prevent crushing the pipe.
Rock Construction Entrance with Wash Rack
Rock construction entrances with wash racks should be considered wherever soil and/or traffic conditions require washing the construction vehicle wheels prior to exiting the site to avoid excessive tracking of mud onto a highway. Access to the site should be limited to the stabilized entrances(s).
NOTE: Wash racks in construction entrances are for washing of tires only. Where it is necessary to wash an entire vehicle prior to leaving the site, this should be done at a site designed to prevent untreated nutrient-enriched wastewater or hazardous wastes from being discharged to surface or ground waters.
At a minimum, rock construction entrances with wash racks should be constructed to the length, width, and thickness dimensions shown on Standard Construction Detail #3-2. A metal wash rack is an acceptable alternative to the reinforced concrete one shown in the standard detail.
Approaches to the wash rack should be lined with AASHTO #1 at a minimum of 25′ on both sides.
The wash rack should discharge to a sediment removal facility, such as a vegetated filter strip or into a channel leading to a sediment removal device (e.g. a sediment trap or sediment basin).
Rock construction entrances with wash racks should be maintained to the specified dimensions by adding rock when necessary at the end of each workday. A stopckpile of rock material should be maintained on site for this purpose.
Sediment Removal Efficiency: HIGH. This device is an ABACT for HQ and EV watersheds.