MR-3: Earthwork Balance

Post by TarekE Aug 13th, 2010
at 12:40 pm

Soil stabilization may have benefits much more than earthworks balance. The most important of which is reduced quarrying. Reduced quarrying may be a credit by itself. Aggregates used in base courses and asphalt layers are produced by quarrying. Quarrying has significant adverse impacts on the environment. Some of the environmental disturbance created by quarrying is caused directly by engineering activities during aggregate extraction and processing. The most obvious engineering impact of quarrying is a change in geomorphology and conversion of lands use, with the associated change in visual scene. This major impact may be accompanied by loss of habitat, noise, dust, vibrations, chemical spills, erosion, sedimentation, and dereliction of the mined site.
As material reuse and recycling were addressed extensively in the manual, the new credit will focus on enhancing the properties of the virgin soil under the carriageway mainly the CBR through the use of chemical stabilization thus reducing/ eliminating completely the need for quarrying. Soil stabilizers beyond the three addressed in the manual (Portland cement, lime and asphalt emulsions) and that are environmentally friendly are available however needs additional extensive testing for use in road bed properties improvement for achieving the goal of reducing quarrying.

Post by JeraleeA Aug 11th, 2010
at 8:59 pm

Thank you for your comments BobH (JanB - BH), but we believe you may be misinterpreting the purpose of this voluntary credit. Importantly, there are no penalties in Greenroads. While you are correct that there is no credit given for the absence of earthwork activities if they are out of scope of the project, it seems that you are suggesting a restorative activity is considered a penalty. It is not. Instead, restorative activities would be considered under Credit EW-6 Habitat Restoration. Landscaping activities are addressed in EW-5 Site Vegetation. Note also that EW-6 carries a higher value (3 points) than this credit, and EW-5 is an additional 3 points. It may be the case that revegetation activities are not considered in as great a detail as perhaps they should be, and we recognize that. We need more information about how to do this if it is not immediately clear how the intent of EW-5 and EW-6 could be met using the activities you suggest. Your comments on these two EW credits would be very valuable and highly appreciated.

Post by JanB Aug 11th, 2010
at 3:29 pm

MR-3 The scoring does not give credit to projects on existing roads that intentionally do not have any cut and fill activity.
The scoring penalizes a project that removes pavement from a roadway and replaces it with restored landscape.
NPS-BH