28. (1) For the purposes of this section, a volume of effluent for a non-event process effluent stream for a day is the volume that flowed past the sampling point established under Part II on the stream during the 24-hour period preceding the pick up of the first sample picked up from the stream for the day. (2) For the purposes of this section, a volume of effluent for a building effluent stream for a day is the volume that flowed past the sampling point established under Part II on the stream during a 24-hour period beginning at any time between 9 a.m. and noon on that day. (3) For the purposes of this section, a 24-hour volume of effluent for an event process effluent stream for a 24-hour period ending at noon is the volume that flowed past the sampling point established under Part II on the stream during the 24-hour period. (4) Each discharger shall determine in cubic metres a daily volume of effluent for each non-event process effluent stream at the discharger’s plant for each day on which a sample is collected under this Regulation from the stream, by integration of continuous flowrate measurements. (5) Despite subsection (4), where a non-event process effluent stream discharges on an intermittent basis, the daily volumes for the stream may be determined either by integration of continuous flowrate measurements or by the summation of individual batch volume measurements. (6) Each discharger shall use flow measurement methods that allow the daily volumes for non-event process effluent streams to be determined to an accuracy of within plus or minus 15 per cent. (7) Each discharger shall determine in cubic metres a 24-hour volume of effluent for each event process effluent stream at the discharger’s plant for each 24-hour period ending at noon in which a sample is collected under this Regulation from the stream or from a tank that discharges into the stream. (8) For the purposes of subsection (7), a discharger need not use continuous flowrate measurements. (9) Each discharger shall use flow measurement methods that allow the daily volumes for event process effluent streams to be determined to an accuracy of within plus or minus 15 per cent. (10) Each discharger shall determine in cubic metres a daily volume of effluent for each building effluent monitoring stream at the discharger’s plant for each day. (11) Subject to subsection (12), each discharger shall use flow measurement methods that allow the daily volumes for building effluent streams determined under subsection (10) to be determined to an accuracy of within plus or minus 20 per cent. (12) For the purposes of subsection (10), in relation to a building effluent stream that originates in the power house at the plant, a discharger for the Lakeview Thermal Generating Station, Lambton Thermal Generating Station, Lennox Thermal Generating Station or Nanticoke Thermal Generating Station may determine the daily volume for the stream for a day as the volume of low pressure service water that served the boiler unit for the stream during a 24-hour period beginning at any time between 9 a.m. and noon on that day. (13) Each discharger shall use methods that allow the daily volumes of low pressure service water determined under subsection (12) to be determined to an accuracy of within plus or minus 20 per cent. (14) Each discharger shall, no later than the day that this section comes into force, determine by calibration or confirm by means of a certified report of a registered professional engineer of the Province of Ontario that, (a) each flow measurement method used under subsections (4) and (5) meets the accuracy requirements of subsection (6); (b) each flow measurement method used under subsections (7) and (8) meets the accuracy requirements of subsection (9); (c) each flow measurement method used under subsection (10) meets the accuracy requirements of subsection (11); and (d) each flow measurement method used under subsection (12) meets the accuracy requirements of subsection (13). (15) Where a discharger uses a new flow measurement method or alters an existing flow measurement method, the discharger shall determine by calibration or confirm by means of a certified report of a registered professional engineer of the Province of Ontario that each new or altered flow measurement method meets the accuracy requirements of subsection (6), (9), (11) or (13), as the case may be, within two weeks after the day on which the new or altered method or system is used. (16) Each discharger shall develop and implement a maintenance schedule and a calibration schedule for each flow measurement system installed at the discharger’s plant and shall maintain each flow measurement system according to good operating practices. (17) Each discharger shall use reasonable efforts to set up each flow measurement system used for the purposes of this section in a way that permits inspection by a provincial officer.  O. Reg. 215/95, s. 28. Calculation of Stream and Plant Volumes

29. (1) Each discharger shall calculate, in cubic metres, a daily non-event process effluent plant volume for each day. (2) For the purposes of subsection (1), a non-event process effluent plant volume for a day is the sum of the daily non-event process effluent volumes for each non-event process effluent monitoring stream determined under section 28 for the day. (3) Each discharger shall calculate, in cubic metres, a monthly average non-event process effluent plant volume for each month by taking the arithmetic mean of the daily non-event process effluent plant volumes for each non-event process effluent monitoring stream calculated under subsection (1) for the month. (4) Each discharger shall calculate, in cubic metres, a monthly average volume for each non-event process effluent stream at the discharger’s plant for each month, by taking the arithmetic mean of the daily volumes determined under section 28 for the stream for the month. (5) Each discharger shall calculate, in cubic metres, a monthly average volume for each event process effluent stream of the type described in paragraph 2 of subsection 1 (3) at the discharger’s plant for each month by taking the arithmetic mean of the 24-hour volumes determined under section 28 for each 24-hour period ending at noon during which a sample is collected from the stream, or from a tank that discharges into the stream, in the month. (6) Each discharger shall calculate, in cubic metres, a monthly average volume for each building effluent stream at the discharger’s plant for each month, by taking the arithmetic mean of the daily volumes determined under section 28 for the stream for the month.  O. Reg. 215/95, s. 29. PART VII   STORM WATER CONTROL STUDY Storm Water Control Study