Proposed provision:

If the background pollutant concentration in a waterbody exceeds an applicable human health criterion for a carcinogen, the Department may authorize a discharge concentration that exceeds that background concentration if:

a.  The mass of the pollutant in the discharge does not exceed the mass that is attributable to the following sources:

i.  The pollutant in the facility's intake water;

ii.  The pollutant in stormwater or other water that flows onto the facility from another property if that property is not controlled by the facility operator or an affiliated entity;

iii.  The pollutant naturally present in the facility’s soils; and

iv.  The pollutant deposited onto the facility from air emission sources that are outside the facility and that are not controlled by the facility operator or an affiliated entity.

b.  The pollutant's concentration after mixing with the waterbody does not exceed the human health criterion at a risk level of 10^-4.

c.  The discharge of the pollutant complies with all applicable technology-based effluent limits, other applicable water quality standards, and the provisions of any applicable total maximum daily load; and

d.  No other technologically and economically feasible means that would not have significant adverse environmental consequences are available to reduce the pollutant concentration in the discharge to the applicable water quality criterion.