N.H. Code Admin. R. Env-Wq 1014.06

Current through Register No. 25, June 20, 2024
Section Env-Wq 1014.06 - Delineation of Wetlands; Hydric Soils Determinations
(a) Wetlands shall be delineated in accordance with RSA 482-A and Env-Wt 100 et seq.
(b) For sites in an undisturbed natural state, the presence or absence of hydric soils shall be determined by evaluating shovel or auger holes to a depth of 2 feet. A sufficient number of holes shall be dug to establish the hydric soil boundary to within 5 feet.
(c) The suitability of a site as a receiving layer shall be determined in accordance with (d), below, if any of the following apply:
(1) No fill has been placed on the site, but the natural vegetation and soil have been disturbed to the extent that it is not possible to determine the presence or absence of hydric soils based on a visual examination of the soil horizons revealed by shovel or auger holes; or
(2) Fill has been placed on the site prior to 1967 for tidal areas, or prior to 1969 for freshwater areas, or pursuant to authorization of the New Hampshire water resources board prior to 1979, or pursuant to a valid permit from the New Hampshire wetlands board issued prior to August 9, 1996, or issued by the department pursuant to RSA 482-A, and either:
a. Visual examination of a test pit establishes that the original soil was hydric, or
b. It cannot be determined by a visual examination of a test pit whether the original soil was a hydric soil or not.
(d) If any of the conditions set forth in (c) above apply, the presence of a suitable receiving layer shall be determined based on the hydrology of the site as shown by data obtained from piezometric monitoring wells in accordance with the following:
(1) One monitoring well shall be placed in the proposed leaching area and one monitoring well shall be placed at a point between 65 and 75 feet downgradient of the proposed leaching area;
(2) Additional monitoring wells shall be installed as needed to establish the 20,000 square foot area required for subdivision applications;
(3) Water level readings shall be taken every 2 weeks;
(4) Water level readings may be taken more often at the option of the property owner;
(5) All readings taken shall be submitted quarterly, in writing, to the department;
(6) Water levels shall be monitored for a period of 2 years;
(7) Based on the recorded data, the applicant shall estimate the seasonal high water table, taking into account weather conditions such as the amount of precipitation over the period, major storm events, frosts and thaws;
(8) The applicant shall submit the estimate together with supporting data to the department; and
(9) The receiving layer shall be deemed suitable if the estimated seasonal high water table is no closer than 15 inches to the existing ground surface.

N.H. Code Admin. R. Env-Wq 1014.06

(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08

Amended by Volume XXXVI Number 41, Filed October 13, 2016, Proposed by #11184, Effective 10/1/2016, Expires 10/1/2026.