N.H. Admin. Code § Env-Wt 307.10

Current through Register No. 45, November 7, 2024
Section Env-Wt 307.10 - Dredging Activity Conditions

In addition to all other applicable conditions in this part, the following conditions shall apply to all dredging activities:

(a) No dredging shall occur that would create violations of any set-backs specified in:
(1) RSA 485-A or RSA 483-B relative to protecting water quality; or
(2) Env-Wq 1000 relative to septic systems;
(b) Work shall be done during low flow or in the dry unless:
(1) A dredge dewatering, diversion, or cofferdam plan has been approved as part of the project;
(2) The project has specific approval based on water depth to operate from a barge; or
(3) The work will be conducted in a lake or pond and turbidity containment can be achieved using turbidity controls;
(c) Turbidity controls shall:
(1) Be installed prior to construction and maintained during construction such that no turbidity escapes the immediate dredge area; and
(2) Remain in place until suspended particles have settled and water at the work site has returned to normal clarity;
(d) Dredged materials shall be disposed of out of jurisdictional areas, unless other disposition is specifically permitted pursuant to (e), below;
(e) If an applicant wishes to use dredged materials as part of the proposed project or dispose of dredged materials in a jurisdictional area, the applicant shall specifically request authorization to do so as part of the application filed pursuant to Env-Wt 311;
(f) Dredged materials to be stockpiled in uplands shall be dewatered in sedimentation basins that are:
(1) Contained within turbidity controls that prevent turbid water from leaving the basins; and
(2) Located outside of any jurisdictional area;
(g) Subject to (h), below, in non-tidal waters, no dredging shall occur:
(1) Between October 1 and March 31 for any documented occurrence of a cold water fishery or threatened or endangered fishery; or
(2) In March or April for any area that is habitat for rainbow smelt;
(h) For logging projects, work shall be done to protect water quality in accordance with the Forestry BMPs, available as noted in Appendix B;
(i) In addition to the limitations on tidal dredging in Env-Wt 600, no dredging shall occur in tidal waters during a fish migration or larval setting stage of fish and shellfish, which is between March 15 and November 15;
(j) In addition to the limitations on tidal dredging in Env-Wt 600, dredging projects in tidal waters shall be designed and implemented to ensure that there is no disruption of tidal flushing. Tidal flushing means the influx or outflow of water that is associated with the normal ebb and flow of the tide;
(k) Dredging shall not impede fish migrations or interfere with spawning areas for fish;
(l) Dredging shall not disturb contaminated sediment unless dredging of such sediment is specifically identified in the application, authorized in the issued permit, and implemented with such protective conditions as are necessary to ensure that the contaminated sediment is properly managed;
(m) Dredging operations that are not related to the operation of a public water supply (PWS) shall be no closer than 250 feet from an active intake for the PWS; and
(n) The permittee shall send prior notification of dredging activities to the PWS owner/operator by registered mail at least 30 days prior to dredging when done in a waterbody or other jurisdictional area within 500 feet of a public water supply intake.

N.H. Admin. Code § Env-Wt 307.10

Derived from Volume XXXIX Number 28, Filed July 11, 2019, Proposed by #12803, Effective 12/15/2019, Expires 12/15/2029 (See Revision Notes #1, #2, and #3 at chapter heading for Env-Wt 300).
Amended by Volume XL Number 46, Filed November 12, 2020, Proposed by #13124, Effective 10/23/2020, Expires 10/23/2030.
Amended by Number 45, Filed November 9, 2023, Proposed by #13777, Effective 10/13/2023, Expires 10/13/2033.