In July 1997, the City of Morenci funded a a Hydrogelogic study. Earth Tech
, a engineering company out of Grand Rapids, MI, completed the survey and delivered a report. While we only include the conclusions of that report here, you can read the full report by visiting City Hall.
Report Title: Hydrogeologic Study and Wellhead Protection Area Delineation
The regional groundwater flow direction for the lower confined aquifer in the City of Morenci is oriented in the South to southeast direction. Groundwater at higher elevations north of the flow toward lower elevations in the Bean Creek Basin. The groundwater gradient across the study area is approximately 0.0018 ft/ft. The average hydraulic conductivity for the aquifer at the production well site based on an estimated thickness is 300 ft/day. The natural groundwater flow velocity in the lower aquifer based on the hydraulic gradient and hydraulic conductivity is 2.7 ft/day.
A groundwater model was developed using the information listed above and other hydraulic characteristic values such as transmissivity, aquifer storage, formation porosity, and aquifer thickness to define the zones of contribution for the community production wells. The delineated areas defined by the model for the 1, 5, and 10 year times of travel (Figure 7) are considered a conservative representation of the Wellhead Protection Area. The size of the 10 year zone of contribution is approximately 14,000 feet in length and 6,000 feet wide and covers an area of approximately 1925 acres.
The vast majority of the delineated wellhead protection area extends into Medina Township from the production well site. Most of the area within the delineated wellhead zone appears to be agricultural in nature with the exception of some minor residential areas. In conclusion, the lower confined aquifer which supplies water for the City of Morenci appears to be very well protected
by the natural presents of clay overlying the lower aquifer.