15. (1) Each discharger shall calculate, in milligrams per litre, a monthly average concentration for each limited parameter in each process effluent monitoring stream of the discharger for each month. (2) For the purposes of subsection (1), a monthly average concentration for a parameter for a month is the arithmetic mean of the analytical results obtained for the parameter from the samples collected under section 22 or 23, as the case may be, from the stream for the month.  O. Reg. 560/94, s. 15. Calculation of Concentrations — Cooling Water Effluent

16. (1) Each discharger shall calculate, in milligrams per litre, a monthly average concentration for each Schedule 2 assessment parameter in each cooling water effluent monitoring stream of the discharger for each month. (2) For the purposes of subsection (1), a monthly average concentration for a parameter for a month is the arithmetic mean of the analytical results obtained for the parameter from the samples collected under section 29 from the stream for the month.  O. Reg. 560/94, s. 16. Calculation of Concentrations — Overflow Effluent

17. (1) Each discharger shall calculate, in milligrams per litre, a daily concentration for each Schedule 3 assessment parameter in each overflow effluent monitoring stream of the discharger for each day on which a sample is collected under this Regulation from the stream for analysis for the parameter. (2) For the purposes of subsection (1), a daily concentration for a parameter for a stream for a day is the arithmetic mean of the analytical results obtained for the parameter from the samples collected under section 30 from the stream for the day. (3) Where there is only one analytical result obtained for a parameter from the stream for a day, the daily concentration for the parameter for the stream for the day for the purposes of subsection (1) is the single analytical result obtained for the parameter.  O. Reg. 560/94, s. 17. PART IV   PARAMETER AND LETHALITY LIMITS Parameter Limits

18. (1) Each discharger shall ensure that each analytical result obtained for each limited parameter from each sample collected from a process effluent monitoring stream at the discharger’s plant does not exceed the daily concentration limit specified for the parameter in Column 3 of Schedule 1. (2) Each discharger shall ensure that each monthly average concentration calculated for a limited parameter under section 15 in connection with the discharger’s plant does not exceed the monthly average concentration limit specified for the parameter in Column 4 of Schedule 1. (3) Subject to subsection (4), each discharger shall control the quality of each process effluent monitoring stream at the discharger’s plant to ensure that the pH value of any sample collected at a process effluent sampling point at the plant is within the range of 6.0 to 9.5. (4) Throughout any day on which a discharger has used an alternate sampling point on a process effluent monitoring stream for sampling required by section 25, as permitted by subsections 25 (7) and (8), the discharger, (a) shall control the quality of the stream to ensure that the pH value of any sample collected at the alternate sampling point on the stream is within the range of 6.0 to 9.5; and (b) need not comply with subsection (3) with respect to the stream.  O. Reg. 560/94, s. 18. Lethality Limits

19. Each discharger shall control the quality of each process effluent monitoring stream and each cooling water effluent monitoring stream at the discharger’s plant to ensure that each rainbow trout acute lethality test and each Daphnia magna acute lethality test performed on any grab sample collected at a process effluent sampling point or cooling water effluent sampling point at the plant results in mortality for no more than 50 per cent of the test organisms in 100 per cent effluent.  O. Reg. 560/94, s. 19. PART V   MONITORING Monitoring — General

20. (1) Despite sections 22 to 30, a discharger need not collect samples from any stream at the discharger’s plant on a day on which process effluent is not being discharged from the plant.  O. Reg. 560/94, s. 20 (1). (2) Despite sections 22, 24 and 30, a discharger need not collect or analyze samples for total cyanide if cyanide is not used at the discharger’s plant. (3) Despite sections 22 and 24, a discharger need not collect or analyze samples for total cyanide from a minewater effluent monitoring stream.  O. Reg. 169/96, s. 4. (4) Where a discharger is required by this Regulation to pick up a set of samples and analyze it for certain parameters, the discharger shall pick up a set of samples sufficient to allow all the analyses to be performed. (5) A discharger shall use all reasonable efforts to ensure that all analyses required by this Regulation are completed as soon as reasonably possible and that the results of those analyses are made available to the discharger as soon as reasonably possible. (6) Subject to subsection (7), each discharger shall pick up all samples required to be picked up at the discharger’s plant under sections 22, 23 and 29 between the hours of 7 a.m. and 10 a.m. (7) If the Director is satisfied, on the basis of written submissions from a discharger, that the circumstances at the discharger’s plant are such that it would be impractical to pick up samples from each process effluent and cooling water effluent sampling point established at the plant under this Regulation within the time period specified in subsection (6), the Director may give the discharger a written notice in respect of the plant, varying the time period specified in subsection (6). (8) Subject to subsections (9) and (10), where a discharger is required by section 22, 23 or 29 to pick up samples, the discharger shall pick up samples collected over the 24-hour period immediately preceding the pick-up. (9) The 24-hour period referred to in subsection (8) may be shortened or enlarged by up to three hours to permit a discharger to take advantage of the three-hour range specified in subsection (6) or of a different three-hour period specified in a notice under subsection (7). (10) Where a notice has been given under subsection (7) in respect of a plant specifying a time period longer than three hours, the 24-hour period referred to in subsection (8) may be shortened or enlarged by up to that longer amount of time to permit the discharger to take advantage of the time period specified in the notice. (11) If the circumstances at a plant change so that the Director is satisfied that the circumstances described in subsection (7) no longer apply at the plant, the Director may revoke a notice given in respect of a plant under subsection (7) by giving a notice of revocation in writing to a discharger for the plant.  O. Reg. 560/94, s. 20 (4-11). Alternate Sampling Procedures