Binational Plans Call for 40 Percent Reduction to Algal-Fueling Nutrients

The Canadian and US governments have each issued domestic action plans to combat Lake Erie’s algal bloom problem and reduce the flow of nutrients into the lake.

The governments hope to reduce the amount of nutrients – notably total phosphorus and soluble reactive phosphorus (a type mixed into water and readily usable by plants) – entering Lake Erie by 40 percent compared to 2008 levels by 2025. It’s an effort to reduce the size and intensity of algal blooms (including toxic cyanobacterial blooms) in the western basin and of hypoxic – or low-oxygen – zones in central Lake Erie.

To aid in this, each country has come up with a plan to reach that goal. The Canadian government developed and issued a singular joint plan with the province of Ontario, finalized and published in February following a public comment period in 2017. A United States plan summarizing federal and state actions was published in March, and is based in part on draft plans by Michigan, Ohio, Pennsylvania, and Indiana.

The plans identify actions each government can undertake to support phosphorus reduction efforts, along with areas where new legislation could strengthen efforts. They also commit Canada and the US to research phosphorus loading into Lake Erie’s eastern basin, and find out reductions the nations should target in the future to deal with excess Cladophora algae growth. A Triennial Assessment of Progress report issued by the IJC in November included several recommendations to governments on the nutrient issue. It noted that blooms have worsened in recent years despite voluntary agricultural programs to reduce phosphorus loads. Both domestic action plans rely on voluntary programs and initiatives to reduce loads, with few mandatory measures.

The IJC previously recommended load targets in 2014 under a Lake Erie Ecosystem Priority (LEEP) report: the IJC finds that current knowledge is sufficient to justify immediate additional effort to reduce external loading of nutrients to Lake Erie.  In particular, the IJC highlights dissolved reactive phosphorus (DRP) as a primary concern and focuses on the Maumee River watershed as the highest priority for remedial action, recommending a 37 percent reduction for the spring period (March-June) compared to the 2007-2012 average.

The Canada-Ontario plan commits the province and federal government to improve watershed planning with stronger ties to municipalities, conservation authorities and indigenous communities to identify phosphorus sources and the best ways to reduce the amount reaching the water, and to restore wetlands and other natural barriers that can hold phosphorus back from the open waters of Lake Erie. The plan includes specific proposals to promote changes to wastewater management and infrastructure in urban areas, and for agricultural land practices.

The US plan echoes the Canadian plan in many respects, seeking out areas where new regulations will be needed, identifying where governments could beef up voluntary programs, and restoring streams and wetlands where possible. The plan notes there are new technologies that could help reduce phosphorus loads entering the water, and that more data needs to be collected on the more bioavailable forms of phosphorus – which could help identify potential sources. Some states have more work to do than others; while Michigan, Ohio and Indiana are working on reductions to the western and central basins of Lake Erie, Pennsylvania is contributing very little to the central basin’s nutrient pollution, and the US plan indicates the state expects its targets to be met without much trouble. New York has agricultural and municipal sources of phosphorus that can enter Lake Erie, but the action plan says not enough is entering the lake from the state to be impairing water quality; it nevertheless plans on reducing phosphorus loads.

On the urban side of things, most single-point sources for pollutants – such as water treatment plants or industrial sites – have already seen drastic reductions in phosphorus since the 1970s, leaving what’s known as “nonpoint sources.”  These may be pollutants from sewer overflows, or waste washed into the water system during a storm.

Ontario is aiming to establish a legal effluent discharge limit of 0.5 milligrams per liter of total phosphorus from municipal wastewater treatment plants that push through 3.78 million liters of water each day by 2020. Ontario also will work with municipalities to upgrade those water treatment plants, reduce the number of combined sewer overflows through infrastructure improvements, and promote green infrastructure that can help reduce runoff. The communities of London and Leamington have specific goals to upgrade wastewater collection facilities, and for the former, separate the wastewater and storm sewer systems.

The US is aiming for upgrades and inexpensive optimization methods of water treatment plants to reduce phosphorus releases, alongside encouraging green infrastructure investments to reduce runoff from stormwater.

The United States also wants to identify and correct failing home sewage treatment systems, which can leak phosphorus into surface and groundwater, incorporate watershed considerations into land use development planning, establish buffer zones to intercept runoff, and phase out residential phosphorus fertilizer applications.

Due to changes in agriculture in Ontario, the Canadian action plan says less hay and wheat is being grown on farmland. These cover crops can help keep soil and nutrients from running off into the water system during the spring melt.

As part of its action plan, Canada wants to encourage farmers to plant cover crops to help hold the soil in place. The government also plans on expanding its promotion of voluntary best management practices to get farms to use several at once, where applicable.

Ontario will work with communities to restore native wetlands and riparian habitats, focusing on areas where phosphorus loads are high and natural cover is low.

The US plan targets cover crops and crop rotation to reduce soil erosion, and promotes reductions in nutrient applications on frozen ground, saturated soils and prior to major rainfall – which Ontario is considering doing legislatively. Much of what’s in the US plan involves voluntary best management practices (albeit with continued evaluation of effectiveness), and no new regulations are being called for on the federal level.

The plan notes that an estimated 99 percent of farms in the western Lake Erie basin are already using at least one conservation practice, and will need to implement multiple ones to make progress.

On the legislative side, Canada is working on changes to its Feeds Regulations that would remove minimum nutrient levels for livestock feed – in turn giving the industry more flexibility to decrease levels of phosphorus in animal feed where it makes sense.

On a federal level, the US has been working on a variety of research and modeling programs, as well as financial and planning assistance for conservation practices through the US Farm Bill and the Great Lakes Restoration Initiative.

These can help local stakeholders and state governments as they work to achieve their respective phosphorus reduction goals. Even with nutrient reduction efforts, government agencies will still be contending with climate change, which could bring changes to the frequency and severity of rainfall events that can wash more nutrients into the water system, new sources of phosphorus, and the amount of nutrients already in the lake.

To contend with those factors, both nations follow “adaptive management” principles for their domestic action plans. What this means is that as knowledge of the ecosystem improves and as efforts get underway to bring down phosphorus loads, Ontario, the states, and the federal governments will regularly review the domestic action plans and adjust them accordingly. The governments put the plans together under the Great Lakes Water Quality Agreement’s Annex 4, which discusses nutrients and algal blooms.

An IJC Fertilizer Application report released in February found gaps in information gathering, policy and management that should be addressed to get a better handle on the nutrient issue. These could include changes to tilling and crop management and tile drainage in agricultural areas, and adjusting future phosphorus targets as the climate changes and potentially becomes wetter.

The IJC’s Triennial Assessment of Progress report also repeated a 2014 recommendation that Ohio declare the western basin of Lake Erie impaired under the US Clean Water Act, which would trigger a federally mandated maximum daily nutrient load for Michigan, Ohio and Indiana. Michigan declared its portion impaired in 2016. Ohio followed in March 2018.

Should the reduced levels of phosphorus called for in the domestic actions be achieved, the governments hope to minimize hypoxic dead zones, drastically reduce bloom conditions similar or smaller to those seen in 2004 and 2012, and keep the biomass of cyanobacteria low enough that it won’t pose a threat to human or ecosystem health.