Oil and grease may be present in a separate phase in ground water. Iron concentrations should be measured to determine the potential for precipitation upon aeration. Alkalinity should also be measured when analyzing for major anions and cations. In addition to chemical parameters, geologic and hydrologic information is usually needed to plan and monitor a ground water remediation. The average r ate of ground water flow can be estimated from the hydraulic conductivity, hydraulic gradient, and effective porosity.
Hydraulic gradient is calculated from ground water elevations measured in monitor wells.
Effective porosity is usually assumed based on ranges of values cited in scientific literature or estimated from pumping tests. Hydraulic conductivity is usually estimated from slug tests or pumping tests. If an active ground water extraction system is being planned, safe aquifer yields and boundary conditions must be established. These parameters require that pumping tests be conducted.