GWA eyes contract to expand aquifer monitoring By Anumita Kaur View Comments The Guam Waterworks Authority may approve a construction contract this week to expand the Northern Guam Lens Aquifer's monitoring system. It's part of a larger effort to rehabilitate and increase the monitoring capacity of the northern aquifer, which supplies the vast majority of the island's drinking water. Waterworks, funded by about $3 million from a Department of Defense grant, aims to have 13 existing monitoring wells at the Northern Guam Lens Aquifer rehabilitated by the end of the year. A construction contract for the existing wells' renovation was awarded to a joint venture between Hawaiian Dredging Construction Company and Core Tech International. Three to four wells are fully refurbished so far, according to GWA General Manager Miguel Bordallo.