September 20, 2002
Introduction
Under the 1987 Protocol to the Great Lakes Water Quality Agreement (Agreement), Remedial Action Plans for designated Areas of Concern are to be developed and implemented by the Parties (Canadian and U.S. Governments) in cooperation with State and Provincial Governments. The Areas of Concern are geographic areas that fail to meet the general or specific objectives of the Agreement, where such failure has caused or is likely to cause impairment of the beneficial use or of the area’s ability to support aquatic life. Further, the Agreement states Remedial Action Plans will be submitted to the International Joint Commission (Commission) for review and comment at three stages:
The Stage 3 Remedial Action Plan for the Severn Sound Area of Concern has been reviewed by the Commission. The criteria for this evaluation were based on the relevant portions of the 1987 Protocol to the Agreement. As defined in Sections 4(d)(iii) and 4(a)(vii-viii) of Annex 2 of the Agreement, respectively, Stage 3 RAPs are to be submitted to the Commission for review and comment when monitoring indicates that identified beneficial uses have been restored. They are to include a process for evaluating remedial measure implementation and effectiveness and a description of surveillance and monitoring processes to track the effectiveness of remedial measures and the eventual confirmation of the restoration of beneficial uses.
General Comments
Does the Stage 3 Remedial Action Plan contain a process for evaluation of remedial measure implementation and effectiveness?
Based on best available information, delisting objectives related to use impairments were developed and reported in the Stage 2 Remedial Action Plan. In order to track the progress of remedial actions towards specific environmental improvements, indicators for the delisting objectives were identified. Technical summaries of selected indicators used to assess delisting objectives were prepared for each use impairment.
In order to evaluate the adequacy and effectiveness of remedial measure implementation, the Stage 3 Remedial Action Plan:
Does the Stage 3 Remedial Action Plan contain a description of surveillance and monitoring processes to track the effectiveness of remedial measures and the eventual confirmation of the restoration of uses?
A monitoring and surveillance plan is outlined in the Stage 3 Remedial Action Plan. The stated purposes of the plan include:
The monitoring and surveillance plan provides a specific, reproducible, and defensible means to verify that restoration has occurred or is occurring. Utilizing appropriate indicators, an evaluation was completed for the following beneficial use impairments:
A summary of the documentation regarding the status of each impaired use and the Commission’s comments concerning progress toward restoration of beneficial uses are provided below.
Restrictions on Fish and Wildlife Consumption
The Stage 3 Remedial Action Plan describes five indicators used to support the determination that no restrictions on the consumption of fish and wildlife from Severn Sound are attributable to local contaminant sources. The Stage 3 Remedial Action Plan confirms that fish consumption advisories for Severn Sound are the same or less restrictive than other areas of Georgian Bay. The document also outlines improvements in the operations of the various municipal sewage treatment plants and notes that the concentration of mercury in sewage treatment plant sludge has generally declined since the early 1990s. The Commission finds that the weight of evidence approach, used in the Stage 3 Remedial Action Plan, is a reasonable method of evaluating remedial measure implementation and effectiveness. Based on the documentation provided in the Remedial Action Plan, the Commission concurs with the determination that restrictions on the consumption of fish and wildlife in the Severn Sound Area of Concern are not attributable to local sources.
Degradation of Fish and Wildlife Populations
The Remedial Action Plan Team developed eight specific objectives to guide fish and wildlife population restoration efforts. A suite of indicators was then utilized to evaluate the status of remedial measure implementation and the effectiveness toward the restoration and protection of the beneficial use. After conducting this evaluation, the Remedial Action Plan Team concluded that, with the exception of two objectives, restoration of the beneficial use has been achieved. These two, unmet objectives are:
In tracking potential effects of remedial activities towards the restoration of these two objectives, indicators confirmed changes in the nearshore fish community which are not reflective of the improvements in water quality parameters achieved under the Remedial Action Plan. The unmet objectives seem to be affected by factors beyond the scope of the Severn Sound Remedial Action Plan.
The Severn Sound Remedial Action Plan stated that the resident fish population should be composed of at least 10 per cent walleye. As of 2001, the Remedial Action Plan noted that, based on an Early Summer Trapnet Survey, walleye composed less than 5 per cent of total catch. Fourteen variables that influence the habitat suitability index for the walleye (http://www.nwrc.gov/wdb/pub/hsi/hsi-056.pdf ) were examined by the Commission. Two variables, average transparency (Secchi depth) during summer and trophic state, were enhanced by remedial actions and the remainder were not influenced. Even though, habitat suitability for the walleye should have increased as a result of Remedial Action Plan implementation, the walleye population has not responded as predicted. Mean age of walleye is decreasing and mortality is increasing. Possible causes, noted in the Stage 3 Remedial Action Plan, include unsustainable harvest levels, introduction of nuisance aquatic species, increases in the double-crested cormorant population, and continuing, record low water levels.
It appears that environmental perturbations outside of the scope of the Severn Sound Remedial Action Plan are responsible for the current condition of the walleye population. Thus, while the beneficial use remains impaired, it is beyond the influence of the Remedial Action Plan and it should not constrain the removal of the Area of Concern designation. The Stage 3 Remedial Action Plan notes that a long-term fish monitoring program is needed. The Commission encourages the responsible agencies to manage the fisheries based on the results of a long-term monitoring program. To assist other Areas of Concern in their efforts to restore fishery populations, the Commission encourages the dissemination of monitoring results as they are obtained from the Severn Sound Area of Concern.
The Commission recognizes that significant environmental concerns outside the scope of the Severn Sound Remedial Action Plan initiative threaten the fishery resources of the Severn Sound Area of Concern as well as the fishery resources of Georgian Bay. Important environmental stressors potentially impacting fisheries include unrestricted development and loss or degradation of habitat, the lack of restrictions on fishing pressure, the introduction or spread of aquatic invasive species, and low water levels. While solutions to these issues are beyond the scope of the Remedial Action Plan, governments need a regional initiative to address these Georgian Bay issues if fish population targets within the Area of Concern are to be achieved.
Degradation of Benthos
Three objectives were established for restoration of a healthy benthos. Indicators to assess progress toward achieving these objectives included examination of the distribution of pollution-intolerant organisms such as Hexagenia spp. and pollution-tolerant species such as Limnodrillus and Tubifex. Sampling, to evaluate the effectiveness of remedial measures such as sewage treatment plant upgrades and elimination of combined sewer overflows, was reported for 1994 and 1998. Twenty-five stations were sampled including open-water as well as near-shore locations. In 1994, the most highly stressed stations were located in shallow conditions near the Main Street Sewage Treatment Plant outfall in Penetang Bay. Conditions at these stations were not representative of the more favourable environment found at open water stations. In 1998, Hexagenia were found at virtually all locations with suitable habitat and tubificid worms were below the maximum target density at 22 of the 25 locations sampled. In the1998 sampling, Penetang Bay showed considerable improvement with Hexagenia nymphs found at 4 sampling sites where they were not detected in 1994. Modelling suggests that the benthic community classified as stressed at Penetang Bay near-shore stations in 1994 was much improved by 1998. Table 1 of the Stage 3 Remedial Action Plan notes that restoration of the beneficial use has been achieved.
Based on the recovery of the benthic community achieved during the sampling period, the Commission concludes that the objective for benthic community structure detailed in the Stage 3 Remedial Action Plan has been achieved and the beneficial use has been restored.
Restrictions on Dredging Activities
The beneficial use impairment, restrictions on dredging activities, provides a means to track additional dredging expenditures by the commercial navigation industry as a result of the handling and disposing of contaminated sediment. No dredging for commercial shipping is required within the Severn Sound Area of Concern. As such, no process for evaluation of remedial measure implementation and effectiveness is required. However, the Stage 3 Remedial Action Plan does contain an evaluation of sediment quality. In general, contaminant levels in Severn Sound sediment are near or below the Lowest Effect Level of the Provincial Sediment Quality Guidelines. Table 1 of the Stage 3 Remedial Action Plan states that the beneficial use is not impaired.
The Commission notes that while there is local maintenance dredging at certain recreational marinas, dredging for commercial navigation is not required and contaminant levels in Severn Sound sediment, in general, meet the Provincial Sediment Quality Guidelines. Accordingly, the Commission agrees with the conclusion that the beneficial use is not impaired within the Area of Concern.
Eutrophication or Undesirable Algae
The Remedial Action Plan Team devised open water and tributary sampling programs in order to determine the effectiveness of remedial measure implementation. Clearly defined open-water objectives were established and goals for reductions of urban storm-water discharges and watershed inputs were outlined. These sampling programs provided the opportunity to evaluate the effectiveness of non-point source pollution control efforts as well as point source control efforts. Sizable reductions in phosphorus loading from sewage treatment plants were achieved through the Remedial Action Plan efforts and further reductions are anticipated through the planned upgrading of the Coldwater sewage treatment plant. Based on the reductions in open water phosphorus and chlorophyll-a concentrations and progress toward a mesotrophic status from the euthrophic status of the 1980's, the Remedial Action Plan Team concluded that this beneficial use impairment has been eliminated.
The Commission is pleased with the progress in reducing phosphorus loading to Severn Sound and encourages the continued cooperation of all levels of government with the local jurisdictions in efforts to ensure the protection of mesotrophic conditions in Severn Sound. The Commission notes that based on Figures 3.8.1, 3.8.2 and 3.8.3 in the Stage 3 Remedial Action Plan, goals for open water trophic indicators are being met and accordingly, the beneficial use has been restored.
Beach Closings
The Stage 3 Remedial Action Plan details a precise objective for the beach closings beneficial use impairment. Provincial objectives for water clarity, pH and indicator bacteria are components of the Remedial Action Plan objective. Comparison of these objectives to water quality conditions at swimming areas provides a means to evaluate the effectiveness of any remedial measure. The Remedial Action Plan Team has concluded that the quality of the swimming areas is generally satisfactory with the exception of sheltered swimming areas receiving occasional discharges of urban storm water, or areas influenced by stream discharges that may have elevated levels of fecal contamination.
One of the specific water use goals for Severn Sound is that the water should be swimmable virtually everywhere. Since swimming occurs wherever there is access to water, this use goal represents an ongoing challenge. Continued efforts will be necessary to achieve and maintain satisfactory conditions in these more marginal swimming areas. The Stage 3 Remedial Action Plan identifies management actions needed to protect public health and to reduce the number of beach closures. These actions and ongoing vigilance will be needed to protect human health in the swimming areas of Severn Sound.
The Commission concludes that the beneficial use in regard to swimming and other body contact is considered restored.
Degradation of Aesthetics
The Stage 3 document provides a definitive objective of algae density such that chlorophyll-a concentrations are less than 5 micrograms per liter. Reductions in phosphorus loadings to Severn Sound have eliminated the incidence of season-long algae blooms especially in Penetang Bay. This objective provides an efficient means for the evaluation of remedial measure implementation. The Stage 3 Report acknowledged that zebra mussels can cause aesthetic problems which are beyond the scope of this Remedial Action Plan.
Based on information provided in the Stage 3 Remedial Action Plan, the Commission concurs that season-long algal blooms no longer occur and the beneficial use is restored.
Degradation of Phytoplankton and Zooplankton Populations
The established objective for restoration of this beneficial use is to ensure phytoplankton species and biovolume are representative of mesotrophic conditions and that the zooplankton population is balanced. The Stage 3 Remedial Action Plan details a process for evaluation of remedial measure implementation. The populations at identified stations were sampled in order to monitor their response to environmental changes. Specifically, sampling of the phytoplankton biovolume was used to assess the response to reductions in phosphorus loading. Although no unimpacted control sites were used as a basis of comparison, from the late 1980s, a 6-fold reduction in phytoplankton biovolume has been noted. Modeling provided estimates of phytoplankton reductions apart from the reductions resulting from zebra mussel populations. Since the early 1990s, zooplankton species richness has increased and biomass has reached a more desirable level. The Remedial Action Plan Team considers the beneficial use to be restored. Periodic monitoring will determine if mesotrophic conditions are maintained with an appropriate relationship between phytoplankton and zooplankton populations.
Based on population data provided in the Stage 3 Remedial Action Plan, the Commission concludes that phytoplankton species and biovolume are representative of mesotrophic conditions and a more balanced zooplankton community is present. The phytoplankton and zooplankton populations are no longer degraded and the Commission considers the beneficial use restored.
Loss of Fish and Wildlife Habitat
Fish habitat suitability was classified for 70 per cent of the Severn Sound shoreline. This inventory identified areas representing critical habitat as well as those areas considered degraded and suitable for restoration. This information has provided a baseline from which development and restoration projects can be reasonably evaluated. Habitat Framework Guidelines which provide an array of measures have been utilized to evaluate upland, riparian and wetland habitat. These Guidelines can be used to guide specific habitat restoration efforts. A large scale habitat protection and improvement project has been undertaken at Matchedash Bay. Specific habitat goals for this project were incorporated into the Remedial Action Plan objectives. The Remedial Action Plan Team reports, based on a qualitative assessment, that restoration targets are met. Ongoing implementation will be required to restore additional degraded habitat and to pursue a no net loss policy toward fish habitat.
The Commission concurs that this use impairment no longer exists but it recognizes that continued vigilance to protect habitat from the strong development pressures is needed if a goal of no net loss is to be achieved.
CONCLUSION
The Commission concurs that to the extent the Remedial Action Plan can have influence over local conditions, beneficial uses in the Severn Sound Area of Concern have been restored. Considerable efforts have been devoted to this goal and the commitment to this achievement has been remarkable. In particular, efforts to reduce phosphorus loads to Severn Sound have resulted in significant environmental improvements within the Area of Concern. The exceptional level of cooperation between the numerous municipalities involved is of particular note to the Commission. Their efforts as well as those of the other members of the Severn Sound Environmental Association are commendable and serve as a model to other Areas of Concern.
The Commission calls for governments to ensure there is regional action that addresses the environmental stressors currently affecting this and other locations on Georgian Bay. In particular, a regional initiative that addresses unrestricted development, the degradation and loss of fish and wildlife habitat, the lack of restrictions on fishing pressure, and the introduction or spread of aquatic invasive species should be considered. The decline of the walleye population and the continued existence of a beneficial use impairment despite remedial actions undertaken by the Remedial Action Plan’s partners highlight the necessity of decisive regional action. Only through such a comprehensive regional effort can the degraded fish population of Severn Sound be fully restored. Such a regional initiative also would provide an opportunity to adequately protect previously restored beneficial uses in locations such as Collingwood Harbour from existing and future threats.