Developing an Ecological Risk Ranking System for Phosphorus for the Lake Champlain Basin

Developing an Ecological Risk Ranking System for Phosphorus for the Lake Champlain Basin

Alison Foster, Scott Ritter, and Alex Arntsen

Problem Statement:

Phosphorus from non-point and point sources contributes nutrient loading in Lake Champlain and its tributaries, which can lead to eutrophication.

Goal/ Purpose Statement:

To categorize risks of sources of phosphorus to the health of Lake Champlain Basin by examining the volume discharged and its effect on aquatic organisms and their habitats. This information can be used to identify appropriate allocation of funds and resources to decreasing decrease phosphorus inputs to the lake.

Justification:

Increased phosphorus loading form from non-point and point sources into tributaries of Lake Champlain has caused increased levels of the nutrient within the lake. The primary issue related to increased phosphorus is the eutrophication within Lake Champlain, which has caused significant algal blooms in some bays. As a result of these blooms, beaches become unsafe and unattractive for recreation as the water develops slime from toxic varieties of cyanobateria. When the algae dies and begins to decay it results in a reduction of available oxygen forcing fish to utilize other habitats. There is also some evidence of accumulation of toxins in fish species that feed on the algae. Should these effects of increased phosphorus load not be dealt with, tourism, fisheries, and safe recreation will be severely impacted.

A wealth of benefits are stood to be gained should phosphorus levels diminish ecologically, economically, and culturally. Lake Champlain is an icon of both Vermont and New York, and is an established and popular tourist destination. Reducing algal blooms and creating a healthy ecosystems for fish will be advantageous to recreational and sport fishing communities, along with supporting diversity and abundance of aquatic organisms. The shores of the lake are also frequently used for recreation as well, and allow for the use of Lake Champlain’s beaches. Ensuring that waters are swimmable is important to the economic income of the region as beaches are a very large source of summer tourism and recreation for the state.

Literature Review:

GIS map of current stormwater permits in Vermont.

Will be used to identify areas of high stormwater runoff and the amount of runoff that should be coming from these areas.

Map of current stormwater permits in New York.

Same function as above.

List of Vermont stormwater impaired areas.

Lists watersheds that have been listed as “impaired” as a result of by stormwater and fail to meet Vermont Water Quality Standards, including a list of the permitted discharges. This information will be used in conjunction with the map above to further identify the major sources of stormwater runoff.

Lake Champlain Phosphorus Total Maximum Daily Load (TMDL)

Although the current TMDL was rejected, it still contains valuable information about the sources of phosphorus in the lake and research regarding what areas and sources in the lake need the most attention.

Ecosystem Indicators and an Environmental Score Card for the Lake Champlain Basin Program

This source describes several indicators relevant to a pressure-state-model representation of phosphorus loading in Lake Champlain. Sources of phosphorous are explained, as are the impacts of phosphorous within the lake.

Effectiveness of a participatory modeling effort to identify and advance community water resource goals in St. Albans, Vermont

Considers stakeholder ideas to reduce phosphorous loading and uses models to determine the impacts on reduction in phosphorus discharge and the costs of the suggested methods. This article will help provide us with a framework to consider stakeholder opinions and provides solid data about the potential effects of different management approaches.

SWAT-predicted influence of different landscape and cropping system alterations on phosphorus mobility

within the Pike River watershed of south-western Québec

This article will provide some about the sources and magnitudes of P loading due to different agricultural land uses. Additional it looks at the effects of agricultural BMP's on total P export.

The Effects of Geology and Land Use on the Export of Phosohorus from Watersheds

This article looks at the effect that geology has on phosphorus loading normalizing for land use. This will be used to adjust our risk values for watersheds with a higher or lower percent of each bedrock type.

Role of Wetlands Surface Water in Champlain Basin in Reducing Phosphorus Loading to Eight Watersheds in the Lake

Study of the impact of natural wetlands on phosophorus loading for eight watersheds in the Lake Champlain Basin. It shows that the total area of wetlands and their proximity to streams had and effect on reducing the total amount of P discharge by the watershed. This will inform our evaluation of the risk within each watershed as it shows that natural wetlands act as phosphorus sinks

Lake Champlain Basin Nonpoint Source Phosphorus Assessment

This article looks at the relative contribution of various land uses on the loading of phosphorus into the lake. This was the source of the phosphorus loading information based on land use found in Opportunities for Action.

The State of the Lake Report, LCBP

This source is a report on the current state of the lake and provides data that will contribute to establishing our ranking criteria. It quantifies phosphorus content in loading within our risk regions for each or our examined sources.

Proposed Effort:

The advantage to examining phosphorus loading into Lake Champlain is that it is a relatively well-understood and studied process. Full lake monitoring for phosphorus and related indicators is well established. At our disposal, we have the most recent data on phosphorus density in different lake segments (State of the Lake, LCBP) as well as determined point and non-point source loading values subjected to these areas. From our research, we have determined the main sources of phosphorus as a stressor to be agricultural and livestock areas, wastewater treatment facilities, and urbanized/developed land cover.

Analyzing how these sources contribute to the examined stressor in the different risk regions is important. Wastewater treatment facilities are most easily quantified. Ranking criteria will establish assigning a score as a function of number of facilities and total discharge. Uncertainties will exist in how positioning of a facility in an area will impact indicators. Agricultural and livestock land along with urban and developed land is more difficult to analyze as a source because they are "non-point" classified. Data does not exist on a small enough scale to standardize the discharge of each farm or the runoff from each neighborhood. Instead, non-point loading of phosphorus is an aggregated figure for each risk region. However, we can use the State of the Lake report estimated loading percentages for agricultural and developed land use types combined with total non-point loading totals to get values of input from both categories. For example, the LCBP concludes that non-point loading in the Main Lake is 139.9 metric tons/year. Developed land accounts for 75% of that load and therefore 104.95 metric tons/year. Ranking criteria can then be assigned based on these calculated values.

The ill-effects of phosphorus include the fact that it acts as a nutrient and promotes too much plant and algae growth creating oxygen deficiencies for other species, affecting the overall functioning of the ecosystem as well as human utilization and enjoyment of the lake. Assessment of endpoints must incorporate the two degrees of impacts: ecological and social. We want the lake to be a healthy system, and we also want people to be able to use and enjoy it. Assessment endpoints for this stressor should include both an examination of phosphorus content in the lake as well as blue green algae blooms. Several lake habitats are affected by phosphorus directly and indirectly. This stressor affects water quality as well as beaches as locations of recreation. In moving forward, we need to determine specific effects of phosphorus on habitats and the receptors within the habitats.

Effort Assignment:

Scott plans to investigate the phosphorus contributions of different types of agriculture, forest cover, and development. Included in this are the beneficial effects of certain cover types, such as wetlands, as a phosphorus sink. This will allow us to assign risk values that are much more representative of the relative contributions of each risk region and non-point source. An additional component of this will be an analysis of the risk that phosphorus loading presents to the habitat within the streams and ponds that drain into the lake.

Alison plans to research current stormwater and wastewater permits to determine how much phosphorus is entering the lake from point sources and to identify areas where input into the lake could be reduced. She also will look into the TMDL to help determine acceptable levels of phosphorus within the lake as a means of developing indicators for our assessment endpoints.

Alex plans to look at the affects of phosphorus on both the ecology of Lake Champlain and community use of the Lake and its waters. Analysis of impacts and effects will strive to cover biological and ecological concerns as well as all stakeholder concerns. We want to know all ways in which the sources of stressors, and the stressor itself are affecting the quality of the Lake Champlain and its tributaries.