Report Number: 144
Year: 2013

The Northern Guam Lens Aquifer database

The Northern Guam Lens Aquifer supplies 80% of the island’s drinking water. Anticipated growth in demand, including a possible surge to support expansion of military activities during the coming decade has elicited interest and support from both the federal and local governments for acquiring tools to support timely development and sustainable management of the aquifer.

This report describes the content and organization of the Northern Guam Lens Aquifer Database, a comprehensive centralized database containing information on custodianship, function, operational status, and the geographical, hydrological, engineering, and geological attributes of each well installed in northern Guam for which records could be found. The database is integrated with current ArcGIS geospatial information visualization tools.

Developed in support of the 2010-2013 Guam Groundwater Availability Study led by the USGS’s Pacific Islands Water Science Center, with funding by the US Marine Corps, and in conjunction with the 2010 NAVFACPAC Exploratory Drilling Program on northern Guam, its integration into WERI’s Guam Hydrologic Survey Program will keep it up to date and make it permanently and readily accessible to professional and scientific users.

The database is also the foundational component for WERI’s topographic map of the basement rock beneath the aquifer. In preparing the database, over 4000 pages of documents were digitally saved and organized into individual electronic folders for each of the 525 wells documented so far.

These include 20 exploratory wells, 1 observation/monitoring wells, 212 drinking water wells, 39 agricultural/industrial wells, and 104 stormwater management wells. Each well folder is electronically linked to its corresponding record in a Microsoft Excel spreadsheet, which contains key engineering and hydrogeological data.

To organize, classify, and relate the enormous amount of disparate data required development of a specialized taxonomic system for the database. This report is thus designed as a user’s manual for the database, providing a detailed description of the indexing system, along with definitions and conventions adopted or devised; data complexities, nuances, and limitations; and assumptions and choices made in interpreting and classifying data.

Finally, recommendations are offered on database maintenance and updating; improvements, refinements, and expansion; supporting operational and administrative procedures; and desirable future studies.

Vivianna Martinez Bendixson