Background

Missisquoi Bay has one of the highest phosphorus concentrations of any part of Lake Champlain. The IJC, in a 2005 report, identified the water quality status in Missisquoi Bay as an urgent matter of binational concern and recommended that the two federal governments take the necessary steps, individually and jointly, to assist in reducing phosphorus levels. According to the report, phosphorus loads (the amount of phosphorus being introduced into the bay) and ambient levels greatly exceed the target levels established by the provincial and state governments. Phosphorus contributes significantly to blooms of blue-green algae during the summer months. As local residents and visitors know, these blooms are often so dense that recreational use is not possible for many weeks at a time.

The Governments of Canada and the United States, in a formal request (known as a Reference) dated August 1, 2008, asked the International Joint Commission (IJC) to coordinate initiatives in both countries to reduce phosphorus loading to Missisquoi Bay on Lake Champlain. The IJC established the International Missisquoi Bay Study Board to help it carry out this responsibility. As one of its first actions under the Reference, the IJC conducted hearings with its Study Board on each side of the international border in the Missisquoi Basin on December 15 and 16, 2008. Members of the public shared their perspectives, concerns and knowledge of local circumstances pertinent to this work.

The Reference recognizes recent scientific advances made by the Province of Quebec in identifying critical sources of phosphorus within its areas of jurisdiction, and specifically asks the IJC to coordinate a number of corresponding tasks on the U.S. side of the border in partnership with the Lake Champlain Basin Program. Among these tasks are:

• identifying critical source areas in the watershed that contribute disproportionately to phosphorus levels in the Missisquoi Bay;
• acquiring and compiling necessary data and imagery; and
• monitoring water quality in small tributaries in the basin over a two-year period.

The outcomes of this work will be compiled and analyzed with other data to provide an integrated picture of the watershed on both sides of the border. Two appropriations from the U.S. Congress totaling $800,000 will support this work. The IJC's final report on the work carried out under the Reference is to be completed by December 2011.

More information is available online at the site of the International Missisquoi Bay Study Board, including the letters of reference from the governments of Canada and the United States to the IJC, the directive from the IJC to its Study Board and transcripts from the public hearings.

LCBP Workshops

The Lake Champlain Basin Program convened four public workshops and meetings to help guide the critical source area identification project. The objectives of the workshops included:

• exploring optimal spatial scale and extent, modeling methods, and parameters for the definition, identification and delineation of critical source areas
• discussing available existing data and gaps in data that would need to be filled
• structuring and designing the short-term monitoring program and discussing long term monitoring needs
• discussing optimal means to compile and analyze information to provide a transboundary understanding of pollutant loads
• examining the role of spring runoff and flooding on nutrient loads
• evaluating the recent information compiled by the USDA NRCS Missisquoi Areawide Plan

The LCBP held the following workshops (please see workshop summaries for more details):

• Tributary Monitoring in the Missisquoi Bay Basin - December 15, 2008 <summary>
• Defining Critical Source Areas and Management Needs - January 22, 2009 <summary>
• Approaches to Identifying Critical Source Areas in the Missisquoi Bay Basin - March 12-13, 2009 <summary>
• Data Availability and Data Needs - April 28, 2009 <summary>

Identifying Critical Source Areas of Phosphorus Pollution

The Lake Champlain Basin Program is seeking proposals, not to exceed $300,000, for technical services to identify predominant types of critical source areas of phosphorus loads, as well as their physical locations. Modeling of these areas is to be performed for the Vermont Sector of the Missisquoi Bay Basin. The goal of this work is to provide resource agencies with a better understanding of the types and locations of areas they should target for better land stewardship in order to significantly reduce the phosphorus loads to Lake Champlain’s Missisquoi Bay. Funding for this project was secured through the International Joint Commission. Due March 5, 2010.

• Request for Proposals

A summary of available geospatial data for this project, as well as links to relevant research projects within the Lake Champlain Basin, can be found below:

GIS Datasets held by the LCBP for use in Identification of Critical
Source Areas of Phosphorus Pollution in the Missisquoi Bay Basin of Vermont [1/10]

The Missisquoi Areawide Plan [1/08]

Lake Champlain Phosphorus Concentrations and Loading Rates, 1990-2008 [12/09]

Phosphorus Loading to Missisquoi Bay from Sub-Basins in Vermont and Québec, 2002-2005 [11/08]

An Environmental Accounting System to Track Nonpoint Source Phosphorus Pollution in the Lake Champlain Basin [First year report: 12/08 | Year 2 Project Workplan: 12/08]

Links between geomorphic condition, water quality, and phosphorus loading in Hungerford Brook, Vermont [10/07]

Updating the Lake Champlain Basin Land Use Data to Improve Prediction of Phosphorus Loading [5/07]

Phosphorus availability from the soils along two streams of the Lake Champlain Basin: Mapping, characterization and seasonal mobility [3/08]

Soil phosphorus landscape variability and soil mapping in a stream corridor of the Northern Lake Champlain watershed [3/09]

Estimating Soil Phosphorus Concentrations along Erodible Stream Corridors in Chittenden County, Vermont [abstract: 1/10]

Bank Stability and Toe Erosion Modeling (BSTEM) of the Missisquoi Watershed [objectives: 8/09]

Quantifying Sediment Loading due to Stream Bank Erosion in Impaired and Attainment Watersheds in Chittenden County, VT Using Advanced GIS and Remote Sensing Technologies [Project Summary: 1/10]

Missisquoi Bay Phosphorus Reduction Agreement [8/02] English | Francais