Section Env-Wq 705.08 - Sewage Pumping Station Ventilation Requirements(a) Mechanical ventilation for personnel and equipment shall be provided for all occupied spaces within sewage pumping stations in accordance with the NFPA as incorporated by reference in the state fire code in Saf-C 6000.(b) Mechanical ventilation for below-grade dry wells shall be provided, so arranged as to independently ventilate the dry well and the wet well.(c) There shall be no interconnection between the wet well and dry well ventilation systems.(d) Switches for operation of ventilation equipment shall be marked and located conveniently.(e) Dehumidification shall be provided in below-ground dry wells.(f) Ventilation of wet wells shall provide at least 30 air changes per hour if the ventilation system is operated intermittently, or at least 12 air changes per hour if the ventilation system is operated continuously.(g) Fans installed within the wet well structure shall be suitable for a class I, division 1, group C and D environment.(h) Ventilation of submersible pump chambers or suction lift wet wells where there is no occupancy for regular maintenance purposes may be by gravity ventilation.(i) Ventilation exhaust from wet wells shall not cause an odor nuisance to the public or surrounding occupied buildings.(j) Access doors to wet wells shall have warning signs on the underside which read, "Warning - Hazardous Area, enter only with proper equipment" or "Confined Space, Entry by Permit Only", as appropriate.(k) The ventilation system of the dry well shall be capable of continuously providing at least 6 air changes per hour when the facility is occupied, and at least 3 air changes per hour when not occupied.N.H. Code Admin. R. Env-Wq 705.08
Adopted byVolume XXXIV Number 46, Filed November 13, 2014, Proposed by #10693, Effective 10/15/2014, Expires10/15/2024.