24. (1) Where a discharger is required by this section to perform a rainbow trout acute lethality test, the discharger shall perform the test according to the procedures described in the Environment Canada publication entitled “Biological Test Method: Reference Method for Determining Acute Lethality of Effluents to Rainbow Trout”, as amended from time to time.  O. Reg. 240/07, s. 4. (2) Each rainbow trout acute lethality test required by this section shall be carried out as a single concentration test using 100 per cent effluent.  O. Reg. 215/95, s. 24 (2). (3) On one day in each month, on a day on which samples are picked up at the plant under subsection 20 (1), each discharger shall collect and immediately pick up a grab sample at each non-event process effluent sampling point at the discharger’s plant and shall perform a rainbow trout acute lethality test on each sample.  O. Reg. 215/95, s. 24 (3). (4) There shall be an interval of at least 15 days between successive pick up days at the plant under subsection (3).  O. Reg. 215/95, s. 24 (4). (5) All samples picked up under subsection (3) in a month shall be picked up on the same day in the month.  O. Reg. 215/95, s. 24 (5). (6) Where a discharger has performed tests under subsection (3) for 12 consecutive months on samples collected from the same sampling point and the mortality of the rainbow trout in each test did not exceed 50 per cent, the discharger is relieved of the obligations under subsection (3) relating to the sampling point and shall instead collect and immediately pick up a grab sample at the sampling point on one day in each quarter and perform a rainbow trout acute lethality test on each sample.  O. Reg. 215/95, s. 24 (6). (7) Samples picked up at a plant under subsection (6) shall be picked up on a day on which samples are picked up at the plant under subsection (3).  O. Reg. 215/95, s. 24 (7). (8) If no samples are being picked up at a plant under subsection (3) during a quarter, samples picked up at the plant during the quarter under subsection (6) shall be picked up on a day on which samples are picked up at the plant under subsection 20 (1).  O. Reg. 215/95, s. 24 (8). (9) There shall be an interval of at least 45 days between successive pick up days at the plant under subsection (6).  O. Reg. 215/95, s. 24 (9). (10) All samples picked up under subsection (6) in a quarter shall be picked up on the same day in the quarter.  O. Reg. 215/95, s. 24 (10). (11) If a rainbow trout acute lethality test performed under subsection (6) on any sample from a sampling point results in mortality of more than 50 per cent of the test rainbow trout, subsections (6) to (10) cease to apply in respect to samples from that sampling point, and a discharger shall instead comply with the requirements of subsection (3) relating to the sampling point, until the tests performed under subsection (3) on all samples collected from the sampling point for a further 12 consecutive months result in mortality for no more than 50 per cent of the rainbow trout for each test.  O. Reg. 215/95, s. 24 (11). (12) A discharger shall notify the Director in writing of any change in the frequency of acute lethality testing under this Regulation at the discharger’s plant, within 30 days after the day on which the change begins.  O. Reg. 215/95, s. 24 (12). (13), (14) Revoked:  O. Reg. 215/95, s. 24 (15). (15) Spent: O. Reg. 215/95, s. 24 (15). (16) Subsections (2) to (15) apply with necessary modifications to each event process effluent sampling point, other than a sampling point on an event process effluent stream of the type described in paragraph 2 of subsection 1 (3), and, for the purpose, (a) the reference in subsection (3) to each non-event process effluent sampling point shall be deemed to be a reference to each event process effluent sampling point, other than a sampling point on an event process effluent stream of the type described in paragraph 2 of subsection 1 (3); and (b) the reference in subsections (3) and (8) to subsection 20 (1) shall be deemed to be a reference to subsection 21 (1).  O. Reg. 215/95, s. 24 (16). (17) Subsections (2) to (15) apply with necessary modifications to the sampling point on the event process effluent stream of the type described in paragraph 2 of subsection 1 (3) and, for the purpose, (a) the reference in subsection (3) to each non-event process effluent sampling point shall be deemed to be a reference to the sampling point on the event process effluent stream of the type described in paragraph 2 of subsection 1 (3); and (b) the reference in subsection (3) to subsection 20 (1) shall be deemed to be a reference to subsection 21 (6).  O. Reg. 215/95, s. 24 (17). (18) Instead of collecting a grab sample from the sampling point on the stream as required by subsection (17), a discharger may collect a grab sample from a radioactive liquid waste management system tank at the plant immediately before a discharge into the stream.  O. Reg. 215/95, s. 24 (18). (19) For the purposes of this section, a discharger at the Bruce Heavy Water Plant may, instead of using a sampling point on a non-event process effluent monitoring stream of the type described in paragraph 7 of subsection 1 (2) or on an event process effluent monitoring stream of the type described in paragraph 5 of subsection 1 (3), use an alternate sampling point located downstream of the sampling point but before the point of discharge of the stream to surface water.  O. Reg. 215/95, s. 24 (19). (20) On one day in each quarter, each discharger shall collect and immediately pick up a grab sample at each building effluent sampling point at the discharger’s plant and shall perform a rainbow trout acute lethality test on each sample.  O. Reg. 215/95, s. 24 (20). (21) Each sample collected under subsection (20) from a sampling point shall be collected on a day on which a sample is collected from that sampling point under subsection 27 (1).  O. Reg. 215/95, s. 24 (21). (22) Subsections (2), (13), (14) and (15) apply with necessary modifications to monitoring under subsection (20) and, for the purpose, the reference in subsections (13) and (14) to subsection (3) shall be deemed to be a reference to subsection (20).  O. Reg. 215/95, s. 24 (22). Monitoring — Acute Lethality Testing — Daphnia magna

25. (1) Where a discharger is required by this section to perform a Daphnia magna acute lethality test, the discharger shall perform the test according to the procedures described in the Environment Canada publication entitled “Biological Test Method: Reference Method for Determining Acute Lethality of Effluents to Daphnia magna”, as amended from time to time.  O. Reg. 240/07, s. 5. (2) Subsections 24 (2) to (22) apply with necessary modifications to Daphnia magna
acute lethality tests and, for the purpose, a reference to rainbow trout shall be deemed to be a reference to Daphnia magna.  O. Reg. 215/95, s. 25 (2). (3) Each discharger shall pick up each set of samples required to be collected from a sampling point at the discharger’s plant under this section on a day on which the discharger collects a sample from the sampling point under section 24, to the extent possible having regard to the frequency of monitoring required at the sampling point under this section and section 24.  O. Reg. 215/95, s. 25 (3). Monitoring — Chronic Toxicity Testing — Fathead Minnow and Ceriodaphnia dubia