Extraction Rate Problems Lead to Increased Costs at Pump‐and‐Treat Facilities: A Call to Improve Reporting of Rates

Abstract

AbstractExperiences at five pump‐and‐treatment (P&T) facilities provide three important lessons:1. To reduce future costs, it is important to use the best hydraulic information possible for designing P&T systems, and to incorporate flexibility to compensate for uncertainties in hydraulic conditions. A phased approach to P&T system construction and hydraulic testing has been successful.2. In practice, downtimes and maintenance problems result in significant reductions in the average ground water extraction rates. This indicates that operation and maintenance were more difficult than expected and warrant more attention. Furthermore, P&T systems are generally designed to attain the model optimized extraction rates only when the system is in full operation. Designers must recognize that P&T systems have downtimes, and, therefore, the uptime pumping must be sufficient to maintain capture. Generally, P&T systems should achieve model‐optimized extraction rates on an average basis rather than only when the system is in full operation.3. During operation of P&T systems, the average extraction rates should be routinely correlated to capture zone evaluations and included in monitoring reports. The average extraction rates should be compared to the model‐derived extraction rates to assess whether the design objectives are being met and should be included in routine monitoring reports to confirm maintenance of pumping rates under which capture has been demonstrated.