Section Env-Wq 715.05 - Ultraviolet (UV) Irradiation Systems(a) An initial assessment of the capabilities of UV disinfection shall be made through transmittance testing to demonstrate the absence of interfering constituents.(b) UV disinfection systems shall deliver UV radiation dosages as demonstrated by plant-specific pilot testing to be effective in maintaining compliance with the bacteriological limits of the discharge permit.(c) The UV disinfection system shall consist of multiple banks of lamp modules capable of disinfecting peak hourly flows with one bank out of service.(d) Provisions shall be made for easy removal and inspection of UV lamps for maintenance or replacement without draining the UV channel.(e) Provisions shall be made for cleaning the lamp sleeves.(f) Provisions shall be made for draining and cleaning the UV channel while maintaining adequate disinfection or storing forward flow.(g) For facilities with a design average flow in excess of 100,000 gpd, UV system controls shall enable UV disinfection system output to be varied in proportion to the effluent flow, percent transmittance, or a combination of both parameters in order to disinfect over the range of water quality conditions.(h) Warning alarms and automatic shutdown shall be provided. Lamp output through the contact area shall be monitored, and a low dosage warning signal shall be furnished.(i) The UV system shall be connected to the WWTP's standby power source and shall be equipped with an uninterruptible power supply to power unit during transfers to and from the standby power source.(j) The UV system shall not produce any dangerous levels of ozone.(k) The UV system operating area shall be ventilated.(l) The UV system shall be fully enclosed in a building for year-round operation.(m) Provisions for measuring UV transmittance shall be provided.N.H. Code Admin. R. Env-Wq 715.05
(See Revision Note at chapter heading for Env-Wq 700) #8590, eff 3-25-06
Amended byVolume XXXIV Number 46, Filed November 13, 2014, Proposed by #10693, Effective 10/15/2014, Expires10/15/2024.