Sandy City, Utah, experienced a fluoride overfeed at one of its drinking water wells in February 2019. HAL investigated the cause, developed a forensic hydraulic model, and prepared the final report.
Summit County Health Department retained HAL to evaluate the Henefer Valley, Coalville/Hoystville/Wanship Valley, and Kamas Valley aquifer systems to determine appropriate septic system densities to prevent excessive groundwater quality degradation. HAL developed a risk-based approach to the mass balance and further supported the justified septic system density limitations through additional research.
HAL prepared a Septic System Density Study for the Pole Canyon drainage area, which is the recharge area for Spanish Fork City’s Cold Springs. HAL researched historic water quality data and performed water quality sampling for comparison to determine the impact of existing septic systems in Pole Canyon on the springs. A detailed hydrogeologic evaluation coupled with the water quality data provided a basis for determining septic system density limits that would protect the City’s drinking water source from excessive water quality degradation.
HAL helped Herriman City develop a management program for septic systems within the Arnold Hollow drainage southwest of the City. Development within Arnold Hollow is a concern to the City because it is the recharge area for the City’s drinking water springs and there are no sewer collection facilities in the area. The program included research and evaluation of existing water quality, characterization of groundwater flow conditions, establishment of maximum septic system densities, and development of a program for approval of selected alternative septic systems that reduce nitrate concentrations in septic system effluent.
HAL assisted Magna Water District with Phase 1 of a Groundwater Management Program to better manage the Barton and Haynes well fields. The study included research and evaluation of historical water quality trends and established prioritized pumping to minimize impact from perchlorate and other water quality challenges. The study also established safe withdrawal rates from the aquifer. Three-dimensional groundwater modeling was used to characterize groundwater flow patterns and predict impacts from pumping alternatives.
HAL assisted the Utah Division of Wildlife Resources with design review and construction support for a new fish screen at Red Fleet Reservoir near Vernal, Utah. The screen keeps non-native game fish from entering the Colorado River system where they would otherwise compete with endangered species.