33 CFR 159.309 - Limitations on discharge of treated sewage or graywater.
(1) The cruise vessel is underway and proceeding at a speed of not less than six knots;
(b) Until such time as the Administrator promulgates regulations addressing effluent quality standards for cruise vessels operating in the applicable waters of Alaska, treated sewage and graywater may be discharged from vessels in circumstances otherwise prohibited under paragraph (a)(1) and (2) of this section provided that:
(3) The geometric mean of the samples from the discharge during any 30-day period does not exceed 20 fecal coliform/100 milliliters (ml) and not more than 10 percent of the samples exceed 40 fecal coliform/100 ml;
(4) Concentrations of total residual chlorine do not exceed 10.0 micrograms per liter (µgm/l);
(5) Prior to any such discharge occurring, the owner, operator or master, or other person in charge of a cruise vessel, can demonstrate to the COTP that test results from at least five samples taken from the vessel representative of the effluent to be discharged, on different days over a 30-day period, conducted in accordance with the guidelines promulgated by the Administrator in 40 CFR part 136, which confirm that the water quality of the effluents proposed for discharge is in compliance with paragraphs (b)(2), (3) and (4) of this section; and
(6) To the extent not otherwise being done by the owner, operator, master or other person in charge of a cruise vessel, pursuant to § 159.317 of this subpart, the owner, operator, master or other person in charge of a cruise vessel shall demonstrate continued compliance through sampling and testing for conventional pollutants and residual chlorine of all treated sewage and graywater effluents periodically as determined by the COTP.