An innovative approach for increasing the performance of ground water pump and treat remedial strategies using high vacuum extraction

Innovative solutions to ground water contamination challenges are well documented in the literature. These solutions range from ex-situ pump and treat approaches to in-situ technologies such as bioremediation, vapor extraction, treatment walls and the like. Several researchers have developed optimization algorithms for ground water pump and treat remedial strategies. A common limitation to pump and treat strategies is the low flow, high drawdown and limited zone of influence that occurs when remediating low permeable (less than 5 ft/day) thin (less than 20 feet) water table aquifers. This paper focuses on the dramatic increase in efficiency in pump and treat systems that can be obtained through the use of the high vacuum (15-20 inches Hg) fluid extraction approach. Ground water flow and transport are described in terms of head and pressure. She paper discusses the flow rate and area of influence limitations on conventional pump and treat technology and the theory behind the advantages in high vacuum extraction technology. Optimal solutions for a sample ground water impact scenario are developed using three dimensional ground water flow and transport codes. The results obtained by using the high vacuum extraction method are presented and compared with results derived by using conventional pump and treat. The results show that high vacuum extraction can substantially increase the efficiency of the clean-up process.