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National Assessment of Pulp and Paper Environmental Effects Monitoring Data

2.0 Introduction

In 1992, the Pulp and Paper Effluent Regulations (PPER) under the Fisheries Act were replaced a 1971 pulp and paper regulation. The PPER set discharge limits for total suspended solids (TSS) and biochemical oxygen demand (BOD). As well, they set a requirement that all discharged effluents should be non-acutely lethal to rainbow trout in 100% effluent. Compliance with the PPER entailed major changes in the way effluents were treated by mills, resulting in most cases in the installation of secondary (biological) treatment. With these amendments, mills were required to install secondary treatment systems as part of their effluent treatment processes. Although it was acknowledged that more stringent discharge limits would improve environmental protection, it was also recognized that these measures alone might not ensure adequate protection of the aquatic environment at every site. Consequently, the 1992 Regulations included a requirement for an environmental effects monitoring (EEM) program.

The National EEM Program requires Canada’s pulp and paper mills to conduct studies on their receiving environments in order to assess and monitor effects potentially caused by their effluent. EEM’s site-specific nature calls for iterative evaluations of the potential effects of effluent on fish, fish habitat, and the use of fisheries resources. The program is structured in a three-year sequence of monitoring and interpretation phases known as “cycles.” At the beginning of each cycle, each mill is expected to develop a site-specific monitoring program in collaboration with regional Environment Canada officials; at the end of each cycle, mills must submit interpretive reports summarizing their field work and interpreting the results. The structure of the EEM program ensures a certain level of national consistency in the way in which mills monitor the effects of their effluent on the environment.

The EEM program provides a long-term evaluation of effluent impacts on the aquatic environment, requiring a minimum of several cycles (15–20 years) to allow an assessment of the condition of the receiving environment and a true understanding of the significance of any impacts. Moreover, EEM provides quantitative and qualitative answers to clear, well-defined questions by measuring responses of organisms and populations to the presence of effluents in exposure and reference areas (Hodson et al., 1996). The program uses a tiered approach to monitoring, with initial studies carried out to characterize and assess the condition of the receiving environment followed by targeted studies once effects are found or reduced monitoring where effects are not occurring. This structure minimizes costs but allows the program to remain scientifically defensible and flexible.

An EEM study includes the following components:

  • a fish population survey to assess the health of fish;
  • a benthic invertebrate community survey to assess fish habitat;
  • a study of dioxins and furans in edible fish tissue and a tainting study as assessments of the usability of fisheries resources;
  • sublethal toxicity testing to assess effluent quality; and
  • supporting water and sediment quality variables to aid in the interpretation of biological data.

The benthic invertebrate community and fish population surveys utilize a select group of “effects” endpoints, which primarily drive future monitoring but also contribute to an understanding of the real nature of impacts (at the site level) from pulp and paper effluent discharges. In EEM, an “effect” is a statistically significant response in at least one of the select endpoints in comparisons between biological samples taken near a mill (exposure area) and samples taken from a reference area. The reference area is a sampling area as similar as possible in all aspects to the exposure area (e.g., same habitat, water quality features, hydrological features, etc.), but without the presence of mill effluent. Unlike the field data, the supporting variables and sublethal toxicity data are not used to determine whether or not environmental “effects” are occurring at mill sites. Rather, they are meant to provide further information on parameters that may or may not have an influence on any observed effects.

The EEM effects endpoints used in the benthic invertebrate community and fish population surveys are as follows:

Benthic invertebrate community survey endpoints:
Total abundance
Taxon richness
Bray-Curtis index of dissimilarity
Simpson’s diversity (or evenness)

Fish population survey endpoints:
Gonad weight
Condition factor
Liver weight
Weight at age

The purpose of this report is to provide a summary of the key outcomes of a more detailed technical report entitled National Assessment of Pulp and Paper Environmental Effects Monitoring Data (Lowell et al., 2003). The national EEM data assessment was primarily designed to assess the type and magnitude of effects occurring on fish populations and benthic invertebrate communities as a result of exposure to pulp and paper effluents across Canada. A series of core questions or priority areas of focus identified by Environment Canada scientists guided the assessment. The questions were fundamental to evaluate the effectiveness of EEM monitoring in assessing the impacts of pulp and paper mill effluents on aquatic environments and to provide the necessary information to understand the ecological importance of these impacts.

In addition to the priority areas identified, the analysis of sublethal toxicity data was carried out to assess overall changes in effluent toxicity before and after the implementation of secondary treatment at most mills. Other components of the National EEM Program (i.e., dioxins and furans in edible fish tissue and tainting) were not the subject of analysis, due to the small number of mills that were required to complete such analyses.

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