Lake Simcoe Phosphorus Reduction Strategy: Is it Enough?
After the Great Lakes, Lake Simcoe is the largest lake in southern Ontario. Its watershed provides a home for numerous wildlife species, including 32 species at risk, as well as widespread agricultural operations, a thriving recreational community and 23 municipalities that represent an expanding urban presence in the region. However, all this development and agricultural activity has caused a steep decline in the water quality of Lake Simcoe and its watershed. This decline is primarily due to phosphorus loadings, which have more than doubled since pre-European settlement rates. In the 1800s, the phosphorus loadings entering the lake were approximately 32 tonnes per year (t/yr), which has been adopted as the baseline level. Currently, the loadings average approximately 72 t/yr.
Significant amounts of this nutrient enter the lake by atmospheric deposition or water run-off from anthropogenic sources, such as the use of fertilizers and detergents, human and animal waste, and industrial processes. The added phosphorus nurtures greater rates of plant and algal growth, which leads to the depletion of the dissolved oxygen concentration in the cold, deeper layer of the lake, which is required habitat for natural populations of cold-water fish, such as lake trout (Salvelinus namaycush).
In June 2010, the Ministry of the Environment (MOE) finalized the Lake Simcoe Phosphorus Reduction Strategy (the “Strategy”). Developed under the Lake Simcoe Protection Act, 2008 and the Lake Simcoe Protection Plan (LSPP), the Strategy is a multi-partner, 35-year phased approach for identifying and reducing major sources of phosphorus entering Lake Simcoe and its watershed. The Strategy builds upon the scientific research, initiatives and planning conducted by the government and various partner groups over the past several decades. The Strategy shares the $20 million provincial investment for Lake Simcoe initiatives.
The Strategy sets out the goal of restoring the dissolved oxygen concentration in Lake Simcoe to 7 milligrams/ litre, which is the concentration needed to support self-sustaining cold-water fish species in the lake. This translates into a reduction of total phosphorus loadings from all major sources from 72 t/yr to 44 t/yr by 2045. Without any action to reduce phosphorus in the watershed, phosphorus loadings are predicted to increase to 94 t/yr by 2045.
The Strategy sets out a reduction target for major sources of phosphorus, as set out in Table 4.3.1.
| Table 4.3.1 Phosphorus Reduction Strategy Summary | |||
|---|---|---|---|
| Source of Phosphorus | % of Total Loadings | Current Loadings (tonnes/year) | Reduction Target set by Strategy |
| Urban runoff and stormwater | 31% | 23 | Moving to no net increase in phosphorus loading from new development. |
| Atmospheric deposition | 27% | 19 | A reduction of 7 tonnes/year (t/yr) by 2045 (3 t/yr in atmospheric deposition in addition to voluntary agricultural stewardship reductions). |
| Rural and agricultural runoff | 25% | 17 | No target set, but reductions are expected from stewardship activities. |
| Sewage treatment plants (STPs) | 7% | 5 | An aggregate baseline load of 7.2 t/yr will be applied to all STPs by 2015 or at their next expansion. Post-2015, the target is an aggregate loading of 3.2 t/yr by 2045. |
| Private septic systems within 100 m of Lake Simcoe | 6% | 4 | No target set. |
| Holland Marsh and smaller polders | 4% | 3 | Reduce total phosphorus load from polders by an estimated 1 t/yr. |
ECO Comment
The ECO commends the Ontario government for creating a watershed-scale Phosphorus Reduction Strategy and acknowledges that this Strategy sets the foundation for the work to come. However, the ECO has some concerns with the Strategy’s proposed approach.
Of greatest concern is the apparent contradiction between the province’s efforts to reduce phosphorus and its Growth Plan for the Greater Golden Horseshoe, which will increase development, and consequently phosphorus, in the Lake Simcoe watershed. Although the Strategy anticipates that urban growth will contribute to increasing phosphorus loadings, it fails to undertake an aggressive approach to ensure these loadings will not overwhelm the lake. Stewardship activities and technology alone will not reduce additional phosphorus loadings from projected future development.
The Strategy lacks sufficient detail and accountability to ensure that phosphorus reduction efforts in the Lake Simcoe watershed will be successful. As seen with other provincial watershed-based initiatives, such as the remediation of Areas of Concern around the Great Lakes (see Part 2.1 of this Annual Report), these projects are expensive, take decades to achieve desired results, involve multiple partners, and require extensive monitoring, public participation and co-ordinated information sharing. However, these key elements are not well defined in this Strategy. The province should not only build upon past phosphorus reduction results but also apply the lessons learned from other remediation efforts.
Furthermore, the Strategy does not outline detailed actions, timelines and, in some cases, targets for the largest sources of phosphorus: urban and agricultural run-off and atmospheric deposition. Although the LSPP required that sub-watershed targets be incorporated into the Strategy, these and other source targets were not included. MOE could have used decades’ worth of past phosphorus reduction activities to assign short-term and long-term reduction targets. Targets and deadlines foster greater accountability for the many Strategy partners and will help the province, stakeholders and the public assess the effectiveness of the Strategy at its scheduled five-year review.
Although the ECO supports stewardship activities, the ECO is concerned by the Strategy’s heavy reliance on voluntary measures for reducing phosphorus loadings from the largest sources. Moreover, the Strategy relies on pre-existing environmental and planning legislation and regulations for compliance, even though they have not been effective in protecting Lake Simcoe. The ministry should couple stewardship programs with effective tools, such as regulations, enforcement activities and financial incentives, to ensure that concrete actions are taken to reduce phosphorus.
Similarly, the Strategy relies on the results of future research activities and technological innovation as key mechanisms to reduce large sources of phosphorus. However, the ECO notes that in some cases, technological advancements may not materialize or may be too costly to implement. Furthermore, the ECO believes that MOE already has access to a strong knowledge base that would allow effective, proactive initiatives to be implemented now.
The province should build strong, proactive phosphorus reductions targets for all the major sources into its Strategy for Lake Simcoe and then use all the enforcement and incentive powers at its disposal to ensure those targets are realized. If pursued diligently and supported with adequate financial and technical resources, this kind of watershed management approach could be adopted province-wide to prevent the deterioration of water quality in other stressed watersheds.
For a more detailed review of this decision, please refer to Section 4.5 of the Supplement to this Annual Report. For ministry comments, please see Appendix C.
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| This is an article from the 2010/11 Annual Report to the Legislature from the Environmental Commissioner of Ontario. |
Citing This Article:
Environmental Commissioner of Ontario. 2011. "Lake Simcoe Phosphorus Reduction Strategy: Is it Enough?." Engaging Solutions, ECO Annual Report, 2010/11. Toronto: The Queen's Printer for Ontario. 64-66.catory:Water Quality
