Technical Memorandum Report No. 9
Progress in the Development of Deep Monitoring Stations in the Pearl Harbor Ground-Water Area, Oahu
Doak C. Cox and Chester Lao.
February 1967
INTRODUCTION
Uncertainties as to the position and behavior of the salt-fresh transition zone at the base of the important, thick Herzberg lenses of Oahu render suspect all determinations of the safe yield of these lenses involving estimates of storage change. A few deep test wells have been drilled to investigate hydrologic conditions in the lower parts of the lenses, but none of these wells has penetrated the lens and entered the salt water beneath. Hence the Water Resources Research Center was greatly interested in the availability for hydrologic monitoring of two large diameter test wells that were drilled in 1965 in the Ewa District for the Hawaii Institute of Geophysics for stratigraphic studies. Each of these wells passed through a considerable section of sediments of varying permeability and then entered the underlying Koolau basalt lava flows which constitute the main aquifer.