Test hole NC-8 was drilled in the municipality of Vega Alta as part of a study of the aquifers in the Northern Coastal Province of Puerto Rico. Test hole NC-8 was drilled to a depth of 1,736 feet below land surface. Geologic and hydrologic data collected during drilling included continuous core, water- quality samples, water-level measurements, and estimates of aquifer yields from the water-bearing zones. Test hole NC-8 penetrated five geologic formations of middle Tertiary age: the Aymamon Limestone, the Los Puertos Formation, the Cibao Formation, the Lares Limestone, and the San Sebastian Formation. Test hole NC-8 penetrated a water-table aquifer and seven artesian aquifers.