DESCRIPTIONS FOR FAIRFAX COUNTY PRIORITY RATING FORM FOR E&S CONTROL

Evaluator - The evaluator is the individual who completes the form.

Denuded Area - Projects that propose denuding more than ten acres will automatically be designated as high priority. Projects that propose up to ten acres of land disturbing activities shall be rated based on the percentage of the overall site that would be disturbed, as well as the factors described below.

Watercourse Crossing - Sites that have a proposed or existing temporary watercourse crossing shall automatically be designated as high priority.

Distance of a Denuded Area to an Adjacent Downstream Property - Sites with the highest probability of causing damage to an adjacent property due to the proximity of proposed land disturbing activities shall receive the highest rating.

Distance of a Denuded Area to a Natural Watercourse - Sites with proposed denuded areas that are less than 50-feet from a natural watercourse shall be given the highest rating. Natural watercourses and their associated floodplains are considered environmentally sensitive land areas in accordance with the Chesapeake Bay Preservation Ordinance, Chapter 118 of the Code of the County of Fairfax, Virginia.

Vegetative Buffer - A vegetative buffer is defined as an area of natural vegetation to remain undisturbed throughout the construction process. The quantity and quality of the natural vegetation determines the effectiveness of the buffer as a filter between a pollutant source and an adjacent property, watercourse or other natural resource. Land areas designated as Resource Protection Areas on Fairfax County tax maps shall not be considered a part of the vegetative buffer when determining the rating in Paragraph E in an effort to maintain the integrity of these sensitive land areas. Existing vegetative buffers that are 50 feet or greater are considered a benefit at reducing potential damage to downstream properties and waterways, by supplementing the required perimeter E&S controls. Vegetative buffers that are 50 feet or greater are assigned a credit in the form of negative rating values in order to recognize their beneficial effects of controlling sedimentation.

Distance Between the Site Outfall(s) and Any Downstream Wetland, Pond, Parkland or Other Land Deemed Environmentally Sensitive by the Director - Sites where stormwater will outfall less than 2,500-feet from a wet pond, wetland, parkland or other land deemed environmentally sensitive by the Director shall be given the highest rating.

Critical Slope(s) Within 50-Feet of an Adjacent Property - If an on-site slope within 50-feet of an adjacent property meets any of the listed criteria, the project shall be given the highest rating.

Soil Erodibility (Based on K Factor) - The soils with K Factors of 0.37 and greater are given the highest rating. The K Factors for all soils groups can be found in Appendix C of the Virginia E&S Control Handbook or the table titled, "Selected Properties for Soils in Fairfax County". The "K" shall be used if the table titled, "Selected Properties for Soils in Fairfax County" is used the K Factor shall be "Crit. K".