N.H. Admin. Code § Env-Wt 904.10

Current through Register No. 50, December 12, 2024

Section Env-Wt 904.10 - Alternative Designs

(a) If the applicant can demonstrate that installing the structure specified in the applicable rule is not practicable, as that term is defined in Env-Wt 103, the applicant may propose an alternative design in accordance with this section.

(b) To request approval of an alternative design, the applicant shall submit a written request to the department, accompanied by a technical report that:

(1) Clearly explains how the proposed alternative meets the criteria for approval specified in (c) or (d), below, as applicable; and

(2) Has been prepared by:

a. An environmental scientist or professional engineer for a tier 1 stream crossing; or

b. A professional engineer for a tier 2, tier 3, or tier 4 stream crossing.

(c) The department shall approve an alternative design for a tier 3 or tier 4 stream crossing if:

(1) The report submitted pursuant to (b), above, demonstrates that adhering to the stated requirements is not practicable, by providing:

a. A detailed financial comparison of the costs of a structure that complies with all applicable design requirements, the proposed structure, and a structure that requires fewer waivers than the proposed structure, with a range of costs estimates for each;

b. A detailed description of the physical limitations of the site; and

c. A hydraulic analysis to show that the proposed stream crossing can accommodate the applicable design storm or that the crossing, together with the associated roadway and roadway embankment, can safely accommodate overtopping flows; and

(2) The proposed alternative meets:

a. The general design criteria established in Env-Wt 904.01; and

b. The applicable design criteria established in Env-Wt 904.07 to the maximum extent practicable.

(d) The department shall approve an alternative design for a new tier 1 or tier 2 crossing if:

(1) The report submitted pursuant to (b), above, demonstrates that adhering to the rules is not practicable;

(2) The proposed alternative design meets:

a. The general design criteria established in Env-Wt 904.01; and

b. The applicable design criteria, established in Env-Wt 904.03(b) for tier 1 stream crossings and in Env-Wt 904.07 for tier 2 stream crossings, to the maximum extent practicable; and

(3) A hydraulic analysis shows that the proposed stream crossing can accommodate the applicable design storm or that the crossing, together with the associated roadway and roadway embankment, can safely accommodate overtopping flows.

(e) The department shall notify the applicant in writing of its decision on the request. If the request is denied, the notice shall specify the reason(s) for the denial. If the request is approved, the permit issued shall include such conditions as are needed to ensure that the project's impacts are minimized.

N.H. Admin. Code § Env-Wt 904.10

Derived from Volume XXXIX Number 28, Filed July 11, 2019, Proposed by #12809, Effective 12/15/2019, Expires 12/15/2029.