40 CFR 420.29: Point of compliance monitoring.

(a) Sintering direct dischargers. Pursuant to 40 CFR 122.44(i) and 122.45(h), a direct discharger must demonstrate compliance with the effluent limitations and standards for 2,3,7,8-TCDF at the point after treatment of sinter plant wastewater separately or in combination with blast furnace wastewater, but prior to mixing with process wastewaters from processes other than sintering and ironmaking, non-process wastewaters or non-contact cooling water, if such water(s) are in an amount greater than 5 percent by volume of the sintering process wastewaters.

(b) Sintering indirect dischargers. An indirect discharger must demonstrate compliance with the pretreatment standards for 2,3,7,8-TCDF by monitoring at the point after treatment of sinter plant wastewater separately or in combination with blast furnace wastewater, but prior to mixing with process wastewaters from processes other than sintering and ironmaking, non-process wastewaters and non-contact cooling water in an amount greater than 5 percent by volume of the sintering process wastewaters.