Projects

Excessive dissolved inorganic nitrogen (DIN) concentrations promote algal growth, and reduce water quality, thereby impacting the structure and function of reef habitats. In response, regulators use water quality monitoring programs that focus on water quality thresholds that usually exclude contributions from groundwater discharge or dilution effects, masking the true human impacts on water quality in coral reefs. To address this need, we developed an island-wide dissolved inorganic nitrogen loading model for Tutuila, to improve understanding of nutrient loads and its impacts on nearshore reef environments. This model is the first of its kind and integrates streamflow data, water budget modeling, and nutrient sampling data from 26 watersheds around Tutuila. Results highlight the effects of groundwater discharge and on-site wastewater disposal systems as a major source of anthropogenic nitrogen to nearshore environments. These results are relevant to managers and regulators in pinpointing specific villages and sources of nitrogen pollution, thereby helping to prioritize efforts to protect reefs and public health in American Samoa.

In the islands of American Samoa, the primary water resources issues, aquifer salinization, excessive drawdowns, etc., are compounded by high losses in the form of non-revenue water caused by a deteriorating and leaky transmission system. To address the need to locate pipes and leaks, a survey team consisting of utility staff and Shuler Hydrologic team members performed a test survey utilizing Ground Penetrating Radar (GPR) to locate and assess water pipe infrastructure on Tutuila, American Samoa. As a geophysical method, GPR uses electromagnetic (radio-spectrum) pulses that are directed into the ground from an antenna. Reflections of these pulses from subsurface features are produced where there is a contrast between the electrical properties of subsurface objects, such as utilities, and the surrounding soil. Potential for use of GPR to detect leaks was also assessed, though the electrical properties of Tutuila's soils did not provide the clarity needed to resolve small leaks.

The American Samoa Water-Use Workplan was developed to assess the current state of water-use information in the territory of American Samoa. This includes territory-wide water-use data such as withdrawals from surface and groundwater sources, water delivery information organized by category of use, return flows back to the environment, and ancillary information including water source, salinity, or populations served. The workplan not only presents information about data availability in American Samoa, but also how data are stored, how data are communicated, and the feasibility of sharing data in their current formats.

Specific objectives for the workplan include:

• Determining which agencies in American Samoa collect water use data
• Developing a list of relevant water user groups in American Samoa
• Cataloging water-use datasets, collecting examples of each, and summarizing data
• Estimating water use from activities for which data is not currently available
• Improving the accuracy, completeness and relevance of water use data
• Increasing water use data storage and accessibility
• Developing organizational strategies to keep and maintain data in a secure, accessible, and easily queried format for communication to outside agencies.

The methodology for data collection included interviews and site visits to territorial agencies involved with water management, distribution, or consumptive use. Where in-person or phone interviews were not possible, inquiries and a standardized interview template were sent via email. Information was collected from the American Samoa Power Authority (ASPA), the American Samoa Environmental Protection Agency (AS-EPA), the American Samoa Department of Commerce (AS-DOC), the American Samoa Department of Agriculture (AS-DOA), The American Samoa branch of the U.S. Department of Agriculture (AS-USDA), The American Samoa Community College (ASCC) Land Grant, and the United States Geological Survey (USGS) Pacific Islands Water Science Center.

American Samoa is currently a world leader in implementation of renewable energy resources on a widespread municipal scale. Goals outlined by the American Samoa Renewable Energy Committee are to power Tutuila with 50% renewable energy by the year 2025, and 100% by the year 2040. However, the feasibility of PV systems is heavily reliant on numerous factors including solar resource availability. This study provided an assessment of solar resource availability at sites throughout Tutuila with a focus on areas of high economic interest such as Aasu Village and Afono Pass.

Contributed to an assessment of the most cost-effective means for providing treated surface water to the Ifitoto community in the upper portion of Faga’alu Village, as well as providing a source of emergency back-up water for the LBJ Tropical Medical Center in Faga’alu.