This chapter shall be known as the “Loudoun County Erosion and Sediment Control Ordinance.” The following law sections are an edited text version of the Virginia Erosion and Sediment Control Law (Title 62. 1, Chapter 3, Article 2.4 of the Code of Virginia, as amended.
The following regulatory sections of the Virginia Erosion and Sediment Control Regulations (9VAC25-840) as amended by the State Water Control Board through 1995, effective March 22, 1995 are incorporated herein.
This chapter also incorporates the Virginia Erosion and Sediment Control Handbook, Third Edition, 1992, or as amended, as a technical guide which contains certain guidelines, standards, criteria, techniques and methods for the control of erosion and sediment resulting from land-disturbing activities, with modifications (a)(1),(a)(2) and (a)(3), as follow, in the effort to meet the requirements dictated by the Virginia Erosion and Sediment Control Law (VESCL) and the Virginia Erosion and Sediment Control Regulations (VESCR). In addition, the “Handbook Minimum Standards”, as set forth in 9VAC25-840, as amended, shall be adopted and enforced to establish minimum design and implementation standards for control measures in the effort to control erosion and sedimentation from land-disturbing activities in Loudoun County.
(a) State Standards & Specifications.
(1) Standard & Specification #1.05 Straw Bale Barrier and #1.07 Brush Barrier. These practices are not to be used without specific authorization from the Director of the Department of Building and Development, with the exception that brush barriers may be used as an interim control prior to the installation of the first phase of the perimeter erosion and sediment controls.
(2) Standard & Specification #1.40 Level Spreader. This practice is not to be used without specific authorization from the Director of the Department of Building and Development.
(3) Standard & Specification #3.13 Temporary Sediment Trap. A pipe outlet sediment trap shall be required for drainage areas of one to three acres. Storage volume calculations shall be based on 134 cubic yards per acre.
(b) State Minimum Standards (MS) 9VAC25-840.
(1) MS-1 - Permanent or temporary soil stabilization shall be applied to denuded areas within seven days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade but will remain dormant for longer than 14 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year.
(2) MS-2 - During construction of the project, soil stock piles and borrow areas shall be stabilized or protected with sediment trapping measures. The applicant is responsible for the temporary protection and permanent stabilization of all soil stock piles on site as well as borrow areas and soil intentionally transported from the project site.
(3) MS-3 - A permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent stabilization shall not be considered established until a ground cover is achieved that is uniform, mature enough to survive and will inhibit erosion.
(4) MS-4 - Sediment Basins and Traps, perimeter dikes, sediment barriers and other measures intended to trap sediment shall be constructed as a first step in any land disturbing activity and shall be made functional before upslope land disturbance takes place.
(5) MS-5 - Stabilization measures shall be applied to earthen structures such as dams, dikes and diversions immediately after installation.
(6) MS-6 - Sediment traps and sediment basins shall be designed and constructed based upon the total drainage area to be served by the trap or basin.
A. The minimum storage capacity of a sediment trap shall be 134 cubic yards per acre of drainage area and the trap shall only control drainage areas less than three acres.
B. Surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to three acres shall be controlled by a sediment basin. The minimum storage capacity of a sediment basin shall be 134 cubic yards per acre of the drainage area. The outfall system shall, at a minimum, maintain the structural integrity of basin during the 25 year storm of 24 hour duration. Runoff coefficients used in runoff calculations shall correspond to a bare earth condition or those conditions expected to exist while the sediment basin is utilized.
(7) MS-7 - cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. Slopes that are found to be eroding excessively within one year of permanent stabilization shall be provided with additional slope stabilizing measures until the problem is corrected.
(8) MS-8 - Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume or slope drain structure.
(9) MS-9 - Whenever water seeps from a slope face, adequate drainage or other protection shall be provided.
(10) MS-10 - All storm sewer inlets that are made operable during construction shall be protected so that sediment laden water cannot enter the conveyance system without first being filtered or otherwise treated to remove sediment.
(11) MS-11 - Before newly constructed stormwater conveyance channels or pipes are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and the receiving channel.
(12) MS-12 - When work in a live watercourse is performed, precautions shall be taken to minimize encroachment, control sediment transport and stabilize the work area to the greatest extent possible during construction. Nonerodible material shall be used for the construction of causeways and cofferdams. Earthen fill may be used for these structures if armored by nonerodible cover materials.
(13) MS-13 - When a live watercourse must be crossed by construction vehicles more than twice in any six month period, a temporary vehicular stream crossing constructed of nonerodible material shall be provided.
(14) MS-14 - All applicable federal, state and local requirements pertaining to working in or crossing live watercourses shall be met.
(15) MS-15 - The bed and banks of a watercourse shall be stabilized immediately after work in the water course is completed.
(16) MS-16 - Underground utility lines shall be installed in accordance with the following standards in addition to other applicable criteria:
A. No more than 500 linear feet of trench may be opened at one time.
B. Excavated material shall be placed on the uphill side of trenches.
C. Effluent from dewatering operations shall be filtered or passed through an approved sediment trapping device, or both and discharged in a manner that does not adversely affect flowing streams or off-site property.
D. Material used for backfilling trenches shall be properly compacted in order to minimize erosion and promote stabilization.
E. Restabilization shall be accomplished in accordance with this chapter.
F. Applicable safety requirements shall be compiled with.
(17) MS-17 - Where construction vehicle access routes intersect paved or public roads, provisions shall be made to minimize the transport of sediment by vehicular tracking onto the paved surface. Where sediment is transported onto a paved or public road surface, the road surfaces shall be cleaned thoroughly at the end of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner. This provision shall apply to individual development lots as well as to larger land disturbing activities.
(18) MS-18 - All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed unless otherwise authorized by the VESCP authority. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.
(Ord. 95-08. Passed 9-20-95; Ord. 05-01. Passed 1-11-05; Ord. 17-12. Passed 12-13-17.)