N.H. Code Admin. R. Env-Wq 1507.02

Current through Register No. 25, June 20, 2024

Section Env-Wq 1507.02 - Criteria for Permanent Methods for Protecting Water Quality

(a) Permanent methods for protecting water quality, including all stormwater management practices, shall be designed to:

(1) Minimize the discharge of pollutants in accordance with Env-Wq 1507.03;

(2) Recharge groundwater in accordance with Env-Wq 1507.04;

(3) Protect channels in accordance with Env-Wq 1507.05;

(4) Control peak runoff rates in accordance with Env-Wq 1507.06; and

(5) Implement long term maintenance practices in accordance with Env-Wq 1507.07.

(b) No component of a stormwater management system shall be:

(1) Constructed below the elevation of the 10 year floodplain for any project within the 100-year floodplain; or

(2) Located in an area of RSA 482-A jurisdiction, unless a permit that specifically allows the proposed impacts has been issued pursuant to RSA 482-A and Env-Wt 100 et seq.

(c) Subject to any practice-specific requirement or exception, no infiltration practice, filtering practice, groundwater recharge practice, treatment swale, pretreatment swale, or sediment forebay shall be located in any of the following areas:

(1) Areas where the stormwater comes from:

a. A high-load area, including but not limited to groundwater protection areas where the stormwater comes from one or more areas where petroleum products are dispensed or otherwise transferred for commercial or industrial purposes; or

b. Areas that have contaminants in soil above site-specific soil standards developed pursuant to Env-Or 600;

(2) Areas that have contaminants:

a. In groundwater above the ambient groundwater quality standards established in Env-Or 603.03; or

b. In soil above site-specific soil standards developed pursuant to Env-Or 600; and

(3) Areas with slopes greater than 15%, unless calculations are provided demonstrating that resulting seepage forces do not cause slope instability.

(d) An overflow structure associated with a stormwater management system shall be designed to convey, in a controlled manner, any flows that exceed the system's capacity.

N.H. Code Admin. R. Env-Wq 1507.02

(See Revision Note #1 at chapter heading for Env-Wq 1500) #9343, eff 1-1-09

Amended by Volume XXXVII Number 32, Filed August 10, 2017, Proposed by #12342, Effective 8/15/2017, Expires 8/15/2027.