Based on the results of the final screening assessment, the Minister of the Environment and the Minister of Health (the ministers) have concluded that selenium and its compounds meet the environmental and human health criteria for a toxic substance, as set out under paragraphs 64(a) and 64(c) of CEPA, respectively, and have therefore recommended the addition of selenium and its compounds to Schedule 1of CEPA. 

Details at: http://gazette.gc.ca/rp-pr/p1/2018/2018-02-17/html/reg2-eng.html

Wastewater facilities are identified as a source of selenium in the environment. According to the screening assessment report secondary treatment (now required by the Wastewater Systems Effluent Regulation), is quite successful in removing selenium.  At this time the government is not proposing any additional compliance requirements, since selenium is well managed within existing industrial regulatory frameworks (ie: WSER and Mining Effluents Regulation). The addition of selenium and its compounds to Schedule 1 of CEPA would not result in any direct impacts (benefits or costs) on our members at this time.