(a) No person directly discharging into the drainage basins of Lake Champlain or Lake Memphremagog shall discharge any waste that contains a phosphorus concentration in excess of 0.80 milligrams per liter on a monthly average basis. Discharges of less than 200,000 gallons per day, permitted on or before July 1, 1991, shall not be subject to the requirements of this subsection. Discharges from a municipally owned aerated lagoon type secondary sewage treatment plant in the Lake Memphremagog drainage basin, permitted on or before July 1, 1991 shall not be subject to the requirements of this subsection unless the plant is modified to use a technology other than aerated lagoons.

(b) Notwithstanding any provision of subsection (a) of this section to the contrary, the Secretary shall establish effluent phosphorus wasteload allocations or concentration limits within any drainage basin in Vermont, as needed to achieve wasteload allocations in a total maximum daily load document approved by the U.S. Environmental Protection Agency, or as needed to attain compliance with water quality standards adopted by the Secretary pursuant to chapter 47 of this title.

(c) [Repealed.]  (Added 1977, No. 39, § 6, eff. April 19, 1977; amended 1981, No. 222 (Adj. Sess.), § 25; 1991, No. 261 (Adj. Sess.), § 2; 1997, No. 51, § 2; 2001, No. 61, § 47, eff. June 16, 2001; 2003, No. 63, § 53, eff. June 11, 2003; 2011, No. 138 (Adj. Sess.), § 27, eff. May 14, 2012; 2015, No. 64, § 47.)