The federal government introduced the Pulp and Paper Effluent Regulations in 1992 to protect fish, fish habitat, and human health by governing the deposit of harmful substances from pulp and paper mill effluents. Mills were required to conduct environmental effects monitoring (EEM) every three years to identify effects on fish and fish habitat.
“After three cycles of EEM, a national assessment found smaller gonads and larger livers in fish downstream from pulp mills, indicating endocrine disruption. While the effects on fish reproduction were well documented, little progress was made on the causes and potential solutions,” says FPInnovations Researcher Pierre Martel. In Cycle 4 of the EEM, the government allowed select mills to partner with researchers from FPInnovations, Environment Canada, and Canadian universities in an effort to find a solution. The multi-agency study aimed to find out how to achieve minimal or no impact on fish reproduction.
A short-term (12 days vs 28 days previously) laboratory test developed at FPInnovations examined the egg production of adult fathead minnows and was shown to be predictive of environmental endocrine disruption. This streamlined version of the test allowed for the quick and efficient testing of more than 80 effluents from 20 mills across Canada. Using the 5-day biochemical oxygen demand (BOD5) test, researchers were in a position to link the effects on fish reproduction to high levels of organic loading in wastewater. For kraft and mechanical pulp mills, effluents containing less than 20 mg/L BOD5 were shown to have the greatest potential for no effects on fish egg production.
“The good news is that existing biotreatment systems are operating with high efficiencies and many consistently reduce BOD5 to levels below 20 mg/L,” says Martel. “Engineers can now make significant improvements in effluent quality and the environment by controlling organic loading to the biotreatment system, with little need to install or invest in new equipment. The study’s findings provide a critical understanding of the problem, offering a big step towards remediation.”
For more information on this project, please contact Pierre Martel.
This article was originally published in the 2016-2017 IMPACT magazine.