250 R.I. Code R. 250-RICR-150-05-2.11

Current through November 7, 2024

Section 250-RICR-150-05-2.11 - Dewatering of Dredged Material

A. Applications that propose dewatering must include the following information:

1. Site plan(s) and engineering plans, including all applicable requirements as identified in § 2.16 of this Part, Appendix A;

2. The selection and design of settling basins shall be consistent with the USACE publication entitled Engineering and Design, Confined Disposal of Dredged Material, Engineer Manual No. 1110-2-5027. Characterization of the dredged material, engineering computations for the system, and analysis of receiving water mixing to demonstrate the discharge will not violate water quality standards must be included. If the dewatering facility processes dredged material from multiple dredging operations, a Rhode Island Pollutant Discharge Elimination System (RIPDES) permit may also be required;

3. A determination that the proposed dewatering location(s) is not within any area prohibited in § 2.5(D) of this Part;

4. Groundwater and surface water classification(s) for the proposed dewatering location(s);

5. The dimensional area and volume of the proposed dewatering, settling and storage basins and staging areas and an estimate of the volume of material capable of being handled at any one time. The proposed basins must be shown on scale drawn site plans with cross sectional views of the berms;

6. Identification of the proposed material handling methods (i.e. hydraulic or mechanical) and an estimate of the proposed volume of runoff water expected from the material;

7. A detailed estimate of the time frame required for each aspect of the dewatering process, which includes receiving, handling, dewatering and transferring dredged material to the final disposal location(s). Where dredged material is proposed for land disposal or beneficial use, sampling for chloride concentration may be required after dewatering;

8. A complete Sediment and Erosion Control Plan describing all aspects of the material transfer; and,

9. A discussion of the proposed methods to be used to reduce material losses when offloading the dredge scows. The proposed method of collecting stormwater runoff from any storage areas and directing it to the settling basins for treatment.

B. All dewatering activities must comply with the standards and criteria for disposal or beneficial use in accordance with § 2.9 of this Part.

250 R.I. Code R. 250-RICR-150-05-2.11