Water Resources Research Act Program

Details for Project ID GU_2024_Habana4

Nitrate-N solute transport model of the Yigo-Tumon Basin, Northern Guam Lens Aquifer

Institute: Guam
Year Established: 2024 Start Date: 2024-09-01 End Date: 2025-08-31
Total Federal Funds: $10,482 Total Non-Federal Funds: Not available

Principal Investigators: Nathan C. Habana

Project Summary: Increased development atop Guam’s sole source aquifer requires proper and strategic wastewater disposal means to reduce the risk of contamination. A recent nitrate solute transport groundwater model of the Swamp Road area in Dededo elucidates the risk of development density and threat to production wells. The model ran four scenarios, with the last simulation tested a case of residential area plans of half and quarter acres as such a scenario as to use septic systems. Model results for such case revealed residentials in high density increased groundwater nitrate-N levels up to 18 mg/L. With the skill and configuration used to develop that model sample, this project applies the same conditions and expands its scope to the entire Yigo-Tumon aquifer basin, which has the most production wells abundantly yielding 20 MGD, nearly half of the total water produced in the Northern Guam Lens Aquifer. The scoped aquifer basin is also the most developed with residential, businesses, and facilities. The model aims to examine the known non-sewered residents and the status impact on water quality. This model may be extremely useful with determining strategies to continue to build and reduce wastewater contamination.