USGS Sponsored Research


Research Priorities

Guam's Critical Fresh Water Resources Research and Training Needs
Identified at Previous Advisory meetings
Updated at September 30, 2011 Meeting, Guam

I. Ground, Surface, and Coastal Water Quality

Impact Issues

Definition: Research that leads to a better understanding of or the possible solution to problems caused by the impact of mans activities or natural processes on Guam´s fresh water quality.

  1. Impact of the projected expansion of military infrastructure on the , aquifer, water supply and waste water disposal systems of the island.
  2. Impact of storm water runoff and ponding basins on groundwater quality.
  3. Impact of conventional septic tanks on the chemistry and biology of groundwater in northern Guam.
  4. Impact of Chamorro Land Trust and other non-regulated activities on land development over the Northern Guam Aquifer.
  5. Impact of sewer outfalls on the quality of streams and the nearshore environment.
  6. Impact of past use of banned pesticides and organic substances on surface and groundwater.
  7. Impact of agricultural activities (including water usage) on ground and surface water resources of Guam.
  8. Impact of existing and proposed future pumping rates on chloride levels in the aquifer, sub-basin by sub-basin, well by well.
  9. Beneficial ecological impact of primary vs. secondary wastewater discharges in remote coastal locations.
  10. Evaluate mitigation techniques for reducing the impact of Guam’s sewage treatment plants on the nutrient loading of receiving rivers, streams and coastal waters.
  11. Potential impact of quarrying activities on the northern Guam’s aquifer.
  12. Assess impacts of El Nino and other decadal and longer-scale drought/storm cycles on aquifer and/or surface catchment recharge, groundwater salinity, and/or other water quality/quantity parameters.

Baseline Issues:

Definition: Research that leads to a better understanding of existing levels of contaminants to serve as a basis to judge the effects of mans future activities on the quality of Guam’s fresh water resource.

  1. Baseline studies to determine if Guam’s drinking water wells fall under the U.S. EPA ter Under the Direct Influence of Surface Water (GWUDI) (GWUDI) rule.
  2. Baseline studies to establish background values of PCBs, pesticides, and heavy metals in estuaries and fresh waters island wide.
  3. Baseline studies to determine continuous salinity/temperature profiles versus rainfall in Guam’s groundwater monitoring wells.
  4. Baseline studies on ground and surface water quality and wetland ecology in watersheds and coastal zones surrounding the proposed new landfill sites.
  5. Baseline bromide/chloride ratios in groundwater to determine suitability of alternative disinfection techniques (specifically ozonation) for GWUDI declared wells.

Modeling Issues:

Definition: Research aimed at developing means of predicting the fate and transport of containments in Guam’s freshwater systems.

  1. Model best management practices for treatment of GWUDI declared drinking water production wells.
  2. Application of existing soil erosion predicting models to various southern Guam watersheds to determine areas of reforestation.
  3. Assist GWA with application of the MWH SOFT/WATER model to various hydraulic and water quality issues.
  4. Modeling surface water contamination from non-point pollution sources, e.g., soil erosion in relation to surface runoff and rainfall.
  5. Identify and quantify natural purification mechanisms at work in the Northern Guam Aquifer system.
  6. Development of a three dimensional groundwater flow model for the Yigo-Tumon trough aquifer for use in water quality studies.
  7. Identification and mapping the sources, locations, movement, and fate of petroleum and other groundwater contaminants under northern Guam.
  8. Spatial and temporal modeling of changes in wetlands and badlands in South Guam Watersheds .
  9. Develop a 3-D groundwater flow model for the area around the proposed new landfill site at Dan Dan.
  10. Identify spatial and temporal concentration changes and trends in contaminants of concern in Guam’s groundwater (dieldrin, chlordane, TCE, PCE, nitrate, chloride, microbiological components). Study to make use of GWA archived water quality data for regulated and non regulated contaminants currently monitored in accordance with the USEPA ‘Standardized Monitoring Framework’ under the Safe Drinking Water Act.

Regulatory Issues:

Definition: Research to investigate the need for new regulations and the effectiveness of existing regulations that deal with Guam’s fresh water quality issues.

  1. Impact of new U.S. EPA Ground Water Regulations on the operation of the GWA groundwater system, with emphasis on the development of Guam specific regulations that best match the requirements in U.S. EPA’s GWUDI rules.
  2. Examine the effectiveness and appropriateness of existing erosion control regulations for the reduction of soil erosion and determine whether these regulations being followed and develop new regulations as appropriate.

New Technologies:

Definition: Studies to investigate the development of, or application of new technologies to improve water quality.

  1. Research to examine the effectiveness of various local soils and substrate mixtures in reducing groundwater contamination of nitrate from septic tanks.
  2. Research engineering and design options for below ground storage technologies for rainwater harvesting and surface water retention.

II. Water Quantity Issues

Definition: Research aimed at gaining a better understanding of the availability, deliverability and sustainability of Guam's surface water, groundwater and rainwater resources.

  1. Develop water budgets for Guam’s surface and groundwater watersheds.
  2. Explore the feasibility of developing a separate surface water supply system for agricultural use in South Guam.
  3. Determine maximum pumping rates for each of Guam’s drinking water production wells, and impact of overall production at adjacent wells, adjacent groundwater sub-basins and the northern Guam lens in general.
  4. Re-evaluation of the North Guam Aquifer sustainable development estimates.
  5. Evaluate the impacts of land development on stream flow, runoff and erosion potential in central and southern Guam.
  6. Quantification and spatial distribution of surface water supplies in Southern Guam.
  7. Field measurements of evapo-transpiration rates in order to better understand and evaluate groundwater recharge on Guam.
  8. Research legal and environmental issues of stream flow depletion resulting from impoundments and surface water diversions.
  9. Develop a three dimensional groundwater flow model for the Yigo-Tumon trough aquifer for use in water quantity studies.
  10. Develop a hydraulic model and a GIS based utility resource management system for GWA’s water supply and wastewater systems.
  11. Expand and updating the rainfall database for Guam with emphasis on:
    • Monthly and annual rainfall distribution maps for the island.
    • Return periods of events calculation (recurrence interval estimates) of extreme rainfall events from 1 minute to 24 h.
    • Rainfall depth-duration-intensity-frequency relationships along with the aerial distribution of rainfall.
    • Long term rain fall variability.
  12. Impact of very large rainfall events on Guam e.g., flooding, erosion, etc.
  13. Continue studies to determine the response of the Northern Guam Lens to various rainfall events.
  14. Conduct feasibility studies for identifying potential sites for small-scale hydropower plant development in southern Guam.

III. Watershed Baseline And Management Issues

Definition: Watershed based research to determine best management practices for reduction in contamination in surface runoff and to provide information on Guam’s surface water sources and the required legislative framework required to protect these resources.

  1. Develop erosion control and rehabilitation plans for South Guam watersheds using risk assessment methods.
  2. Develop appropriate management strategies to protect and improve the quality of water supplied to the Ugum water treatment facility.
  3. Investigations to determine the adequacy of Guam’s existing laws dealing with water rights regarding the provision of economical and expeditious development of Guam’s water supply.
  4. Evaluate the accuracy and enforceability of Guam’s existing flood plain maps.
  5. Continue studies to provide more reliable information on sediment sources under varying watershed conditions.
  6. Undertake dye-trace, flow path mapping, and water chemistry studies related to runoff from Marine Drive, the International Airport, Tiyan, and the Harmon Industrial Park.
  7. Development of a watershed atlas for south Guam Watersheds.
  8. Explore sources of sedimentation problems in Fena Reservoir .
  9. Determine the impact of sedimentation processes on the biota of streams and the near shore marine environment.
  10. Dye trace study to determine where waters exiting from the middle reaches of the Togcha River (interrupted river) reappear in the adjacent coastal belt.
  11. Develop practical low-cost methods for reducing beach erosion in southern Guam.
  12. Develop a synthesis of badland restoration practices, providing a comparative analysis of cost effectiveness and suitability for southern Guam watersheds.
  13. Map and determine sediment loads impacting the Sigua River as a result of ‘off-roading’ activities within the watershed.
  14. Determine the impact on soil erosion of ‘off-road’ recreational vehicle use in Guam’s watersheds. How will this be affected by the projected military build-up and what should we do about it? .
  15. LIDAR based drainage delineations of all southern Guam watersheds.

IV. Education And Professional Training

Definition: Projects that lead to the public’s better understanding of water resources issues to include water resources training courses and workshops for k-12 students and teachers, the general public and island water resource managers and decision makers.

  1. Executive training on water resources issues for Legislators and Gov Guam senior management officials, including CCU.
  2. Develop community water resources awareness and education projects.
  3. Develop K-12 education projects on island water resources and pollution prevention similar to that developed by WERI for school teachers in FSM.
  4. Develop sediment mitigation workshops for badlands as well as construction sites.
  5. Promote water related intern programs for environmental science students in Gov Guam agencies. In particular, there is a need for an internship with GWA for water system modeling and geographic information systems.
  6. Develop advanced courses in hydrology, hydraulics and water system modeling for engineers at GWA and Guam EPA.
  7. Develop various water resources oriented GIS applications that would be useful to agency officials and others that could be made available to the general public.
  8. Develop public education programs on the costs of water quality.
  9. Develop water and waste water system operator’s certification training.
  10. Develop programs to provide general education of the public on how to provide safe drinking water in their homes.
  11. Develop training modules and templates for the development of community based watershed management programs.
  12. Develop teacher training courses in water resources related subjects.
  13. Develop general public training in water resources issues especially in getting technical matters into a language the general public can understand.
  14. Outreach programs to educate citizens without access to the World Wide Web.
  15. Develop educational training and outreach programs within the community about the importance of protecting and preserving our water resources. Educational outreach programs should begin with elementary schools in order to instill the importance of these issues at a young age.
  16. Design research data driven training courses for Guam Waterworks Authority to facilitate improved management practices of the island’s water resource.
  17. Develop and conduct a wastewater system hydraulic modeling course that parallels the current water system modeling course designed by WERI.

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