7 Del. Admin. Code § 5101-4.0

Current through Reigster Vol. 28, No. 6, December 1, 2024

Section 5101-4.0 - Performance Criteria for Construction Site Stormwater Management

4.1 All construction site stormwater management practices shall be consistent with the current version of the Delaware Erosion and Sediment Control (ESC) Handbook. A proposal to use temporary control measures that are not included in the current version of the Delaware ESC Handbook shall be submitted to the Department for approval. The proposal shall be accompanied by supporting documentation as necessary to determine appropriateness of the proposed temporary control measure for the proposed use.

4.2 A sequence of construction shall be provided on plans describing the relationship between the implementation and maintenance of erosion and sediment controls, including permanent and temporary stabilization and the various stages or phases of earth disturbance and construction.

4.3 Best available technology (BAT) shall be employed to manage turbid discharges in accordance with requirements of 7 Del.C. Ch. 60, and the current Delaware Construction General Permit (CGP).

4.4 Limits on Land Disturbance

4.4.1 Unless an exception is approved on a case by case basis for a specific type of activity by the appropriate plan approval agency, not more than 20 acres may be disturbed at any one time. This will necessitate the phasing of construction on sites in excess of 20 acres to minimize areas exposed of ground cover and reduce erosion rates. Disturbance of a second 20 acre section may not proceed until temporary or permanent stabilization of the first 20 acre section is accomplished.

4.4.2 If approved by the Department or Delegated Agency sites may disturb greater than 20 acres . Sites having disturbed areas greater than 20 acres shall comply with the following:

4.4.2.1 Construction site stormwater management BMPs shall be designed for disturbed drainage areas greater than 20 acres and shall have supporting design computations, including but not limited to storage, conveyance, stability, and treatment capabilities based on the 2-year storm event with bare earth conditions.

4.4.2.1.1 Conveyance measures shall be designed to have adequate capacity for conveyance of flow in a non-erosive manner.

4.4.2.1.2 Storage practices shall be designed to adequately contain the volume of the design storm event.

4.4.2.2 Reasonable precautions shall be taken to control dust at all times. Dust shall be controlled by applying adequate amounts of water, chemical stabilizer, or other effective dust suppressant.

4.4.3 All plans shall include a limit of disturbance line (L.O.D.) establishing the maximum necessary extent of land disturbance required to implement and accomplish the permitted site construction for land disturbing activities subject to these Regulations.

4.5 Stabilization

4.5.1 Following soil disturbance or re-disturbance, Permanent or Temporary Stabilization shall be completed for perimeter sediment controls, topsoil stockpiles, and all other disturbed or graded areas on the project site within 14 calendar days unless more restrictive Federal requirements apply.

4.5.2 Documentation of soil testing and materials used for temporary or permanent stabilization including but not limited to soil test results, seed tags, soil amendment tags, etc. shall be provided to the Department or Delegated Agency to verify that the permanent or temporary stabilization has been completed in accordance with the approved plan.

4.5.3 The Department or Delegated Agency may require additional soil testing and reapplication of permanent or temporary stabilization in accordance with the specifications in the Delaware Erosion and Sediment Control Handbook, or alternative measures that provide functional equivalency.

4.5.4 Release of either a financial guarantee or issuance of Notice of Completion or both shall not occur until final stabilization of exposed areas is achieved.

7 Del. Admin. Code § 5101-4.0

18 DE Reg. 396 (11/1/2014)
22 DE Reg. 680 (2/1/2019) (Final)