Q-2, r. 34.1 - Regulation respecting municipal wastewater treatment works

Full text
(s. 7)
(1) The effluent from a treatment plant must undergo an acute toxicity test performed on rainbow trout (Oncorhynchus mykiss) and another performed on daphnia Daphnia magna in accordance with the most recent version of one of the following methods:
(1) for rainbow trout (Oncorhynchus mykiss): biological test method EPS1/RM/13 “Biological Test Method: Reference Method for Determining Acute Lethality of Effluents to Rainbow Trout”, published by Environment Canada, carried out according to the single-concentration or multi-concentration procedure, as the case may be;
(2) for daphnia Daphnia magna: MA 500 – D.mag. 1.1 lethal toxicity method “Détermination de la toxicité létale CL50 48h Daphnia magna”, published by the Centre d’expertise en analyse environnementale du Québec of the Ministère du Développement durable, de l’Environnement, de la Faune et des Parcs.
(2) Acute toxicity tests are performed at the following frequencies, according to the class of treatment plant concerned, unless different frequencies are provided in the depollution attestation issued under section 31.33 of the Environment Quality Act (chapter Q-2) for the municipal wastewater treatment works concerned:
Requirements of acute toxicity tests

Class of treatment plant Acute toxicity tests Frequency of acute
toxicity tests

Medium - Rainbow trout Quarterly1
- Daphnia magna

Large - Rainbow trout Quarterly1
- Daphnia magna

Very large - Rainbow trout Monthly2
- Daphnia magna

1. Quarterly tests must be at intervals of at least 2 months.
2. Monthly tests must be at intervals of at least 3 weeks.
(3) If a positive result is obtained for an acute toxicity test, the operator must, within 7 days, have a second test performed on the same species. If the result of the second test is negative, the operator must have a third test performed on the same species, within 7 days, to determine the final result of the test.
For rainbow trout (Oncorhynchus mykiss), the second and third tests must be performed according to the multi-concentration procedure of the method provided for in paragraph 1 of section 1.
O.C. 1305-2013, Sch. II.