21. (1) Where a discharger is, by virtue of subsection 7 (1), required by the Ministry of the Environment publication entitled “Protocol for the Sampling and Analysis of Industrial/Municipal Wastewater”, as amended from time to time, to collect a composite sample for any sample required to be picked up at a stream at the discharger’s plant under this Regulation, the discharger may collect the composite sample by collecting three equal volume grab samples from the stream at intervals of at least two hours and combining them.  O. Reg. 234/07, s. 3. (2) A discharger who is required to collect a composite sample from a process effluent monitoring stream under section 22 or 23 may instead collect a single grab sample from the stream if, (a) the process effluent monitoring stream flows from a tailings area or any other wastewater treatment facility associated with a tailings area and the retention time calculated under subsection (3) in relation to the stream is 30 days or more; or (b) the process effluent monitoring stream does not flow from a tailings area or any other wastewater treatment facility associated with a tailings area and the retention time calculated under subsection (3) in relation to the stream is five days or more.  O. Reg. 560/94, s. 21 (2). (3) Retention time in relation to a process effluent monitoring stream is the period of time in days that results from dividing the total available volume, expressed in cubic metres, of the wastewater treatment facilities on the stream by the average daily flow, expressed in cubic metres, of the stream.  O. Reg. 560/94, s. 21 (3). (4) For the purposes of subsection (3), the total available volume of the wastewater treatment facilities on the process effluent monitoring stream is the volume of the wastewater treatment facilities that may be occupied by water on any day within the 90-day period preceding the date of the calculation of the retention time, taking into account, (a) any requirements that apply in respect of the operation of those facilities in any Act or in any approval, order, direction or other instrument issued under any Act; and (b) any solid waste or sludge contained within those facilities on the day of the calculation of the total available volume of those facilities.  O. Reg. 560/94, s. 21 (4). (5) For the purposes of subsection (3), the average daily flow of the process effluent monitoring stream is the arithmetic mean of the 30 highest daily volumes calculated under section 31 in relation to the stream within the 90-day period preceding the date of the calculation of the retention time.  O. Reg. 560/94, s. 21 (5). (6) The discharger of an existing plant to which Ontario Regulation 491/89 applies may include the days of flow calculated under section 5 of that Regulation in relation to the stream between August 26, 1994 and November 23, 1994 for the purposes of calculating the average daily flow of the process effluent monitoring stream.  O. Reg. 560/94, s. 21 (6). (7) A discharger may sample at a process effluent monitoring stream in the manner described in subsection (2) for the period of time during which the retention time calculated in relation to the stream is in effect.  O. Reg. 560/94, s. 21 (7). (8) A retention time calculated under this section expires 365 days after the date on which the calculation is made or on the date that a new retention time is calculated under this section, whichever date is sooner.  O. Reg. 560/94, s. 21 (8). Monitoring — Process Effluent — Thrice Weekly

22. (1) Each discharger shall, on three days in each week, pick up a set of samples collected at each process effluent sampling point at the discharger’s plant and shall analyze each set of samples for the parameters for which the frequency of monitoring, as set out in Column 2 of Schedule 1, is thrice weekly. (2) There shall be an interval of at least 24 hours between successive pick-up days at the plant under subsection (1). (3) All samples picked up under subsection (1) in a week shall be picked up on the same three days in the week.  O. Reg. 560/94, s. 22. Monitoring — Process Effluent — Weekly

23. (1) Each discharger shall, on one day in each week, pick up a set of samples collected at each process effluent sampling point at the discharger’s plant and shall analyze each set of samples for the parameters for which the frequency of monitoring, as set out in Column 2 of Schedule 1, is weekly. (2) There shall be an interval of at least four days between successive pick-up days at the plant under subsection (1). (3) All samples picked up under subsection (1) in a week shall be picked up on the same day in the week.  O. Reg. 560/94, s. 23. Monitoring — Process Effluent — Quality Control

24. (1) On one day in each year after 1994, on a day on which samples are picked up at the plant under subsection 22 (1), each discharger shall collect and pick up a duplicate sample for each sample picked up on that day under subsection 22 (1) at one process effluent sampling point at the discharger’s plant and shall analyze each duplicate sample for the parameters for which the frequency of monitoring, as set out in Column 2 of Schedule 1, is thrice weekly.  O. Reg. 560/94, s. 24 (1). (2) On one day in each year after 1994, on a day on which samples are picked up at the plant under subsection 23 (1), each discharger shall collect and pick up a duplicate sample for each sample picked up on that day under subsection 23 (1) at one process effluent sampling point at the discharger’s plant and shall analyze each duplicate sample for the parameters for which the frequency of monitoring, as set out in Column 2 of Schedule 1, is weekly.  O. Reg. 560/94, s. 24 (2). (3) Each discharger shall ensure that the same process effluent sampling point is used at the discharger’s plant for the purposes of sampling under subsections (1) and (2) in a year.  O. Reg. 560/94, s. 24 (3). (4) Each discharger shall prepare a travelling blank and travelling spiked blank sample for each sample for which a duplicate sample is picked up at the plant under subsection (1) or (2) and shall analyze the travelling blank and travelling spiked blank samples in accordance with the directions set out in the Ministry of the Environment publication entitled “Protocol for the Sampling and Analysis of Industrial/Municipal Wastewater”, as amended from time to time.  O. Reg. 234/07, s. 4. (5) There shall be an interval of at least six months between successive pick-up days at the plant under subsections (1) and (2).  O. Reg. 560/94, s. 24 (5). Monitoring — Process Effluent — pH Measurement