The following studies are expected to begin over the next two years. Each study requires an EPA approved sampling plan and necessary permits from the National Park Service, Washington State agencies, and area tribes. Studies, data analysis and interpretation can take several months. Further, before data analysis and interpretation are released to the public, EPA conducts a review and approval process that includes a tribal and inter-agency comment period.

Surface Water

Chemicals of interest, e.g.-- metals, mercury and organic compounds, may be present in Lake Roosevelt's water. This study will address the following types of questions:

At any location tested, are chemicals of interest below or above protective criteria and guidelines for ecological and human health?
Are chemicals of interest more concentrated in certain areas or water depths?
Do chemicals of interest pose unacceptable risks to aquatic life, wildlife or humans by migrating up the food chain?

The surface water study will take place at multiple locations from the Canadian border to Grand Coulee Dam (see map page 11), and during different times of the year.

Fish Tissue

Extensive fish tissue data was gathered in 2005 and led to an updated fish advisory (see page 6) in 2008. Another round of fish tissue collection is being done to address the following types of questions:

What are the tissue concentrations of chemicals of interest in fish species that are eaten by birds, mammals, and other fish? Can these concentrations affect the health of these species or other species that may prey on them?
What are the tissue concentrations of chemicals of interest in fish species, e.g.--kokanee, that have not been extensively tested in the past?
Does sampling that addresses recreational and tribal human health concerns result in similar findings to 2005 sampling?

Fish are expected to be collected in the September/October 2009 time frame in different locations throughout Lake Roosevelt (see map page 11). Game fish expected to be sampled include walleye, rainbow trout, lake whitefish, largescale sucker, burbot, smallmouth bass, and kokanee. Small body fish (e.g., yellow perch) are also being collected to evaluate ecological concerns.

Beach Sediment Studies

Beach sediment data was collected at 15 beaches in 2005 and led to an initial finding that exposure was safely below human health-based risk standards (see page 7).

New sampling will be expanded to include 34 beaches from the Canadian border to Grand Coulee Dam (see map page 11). This study will focus on the following types of questions:

Do metals concentrations pose unacceptable risks to human health or the environment?
What are the spatial distributions, physical properties and other characteristics of chemicals of interest? Do these distributions, properties and characteristics provide pathways for chemicals of interest to become present in other parts of the environment?

Sampling is expected to begin in the summer of 2009 for beaches unaffected by lake levels and during the spring of 2010 when lake levels are low and exposed beaches high.

chart to enlarge and/or print.

Zooplankton Tissue

Zooplankton is at the base of the aquatic food chain. They include a range of organisms that can drift in the water and individually are undetectable to the naked eye. Lake Roosevelt zooplankton such as water fleas are a critical dietary source for fish in Lake Roosevelt. This study will focus on the following types of questions:

Do chemicals of interest pose an unacceptable risk to the health of zooplankton?
Do concentrations of chemicals of interest in zooplankton create a health risk for fish that prey on zooplankton?

Resource Use and Consumption Surveys

Part of the human health risk assessment requires an understanding of how often people are being exposed to possible risks. For the general public, the resource use survey will focus on the following types of questions:

What recreational areas are typically visited, how often, and at what times of the year?
What recreational activities are taking place, e.g.--fishing or sunbathing?
For each activity taking place, what's the duration (e.g.--length of time on a beach), type of exposure (e.g.--swimming), and type of consumption pattern (e.g.--number and type of fish being caught)?

A survey for the Colville Confederated Tribes will also take place. This survey will focus on exposure and activities specific to their culture and lifestyle as year round residents.

Resource surveys will be tested during 2010, and then fully deployed.