The purpose of this chapter is to provide for the attainment and protection of the surface water quality standards (WQS) established in Chapter 3745-1 of the Administrative Code. This chapter sets forth rules for developing water quality based effluent limitations for point sources and total maximum daily loads (TMDLs) for discharges of any pollutant requiring control, including toxic, carcinogenic, and organoleptic pollutants. This chapter specifies how to determine when a wasteload allocation is necessary, how to calculate a wasteload allocation, how to determine the reasonable potential of a pollutant to cause or contribute to an excursion of the WQS, and how to develop a TMDL for a pollutant. Except as provided in paragraph (M) of rule 3745-2-12 of the Administrative Code, the methods in this chapter do not apply to establishing controls on the discharge of any pollutant by a wet weather point source. Wasteload allocations and TMDLs for wet weather point sources are determined using stream or basin specific models.