For Quad Knopf, Inc., and County of Merced Planning Department
Merced County, California

 Questa recently completed a detailed hydrologic and water quality investigation and CEQA analysis of the proposed Gomes Diary in northwest Merced County. The startup dairy would milk over 1,200 animals in a central milking barn. Facility wastes would be removed by a pressure wash system to a central treatment plant for primary and secondary treatment. Wastewater disposal would be via pasture basin flood irrigation to the 1500-acre farm, with wastewater effluent metered in with irrigation make-up water drawn from onsite wells. The onsite hydrogeology is complicated, as groundwater occurs in a shallow zone that may communicate with surface drainages, a deep, unconfined zone, and a very deep, confined aquifer. Further complicating the situation is the fact that many of the wells apparently draw water from several zones.

 Water quality issues, including salt and nitrate loading to groundwater and runoff impacts to the nearby Chowchilla River, were major issues addressed in the EIR. Questa's work scope included completing a field water quality sampling and well monitoring inventory, a hydrogeologic study, and a detailed water balance-based model of the movement of salts and nitrates through the shallow and confined aquifer. Mitigation measures were then recommended to reduce the impacts of salts and nitrate buildup on the shallow groundwater table and to better control surface runoff impacts.