6.1 Introduction.................................................................................................. 99
6.2 Site Background ......................................................................................... 100
6.3 Site Evaluation ............................................................................................ 101
6.4 Outcomes .................................................................................................... 102
6.4.1 Chromium....................................................................................... 102
6.4.2 Volatile Organic Compounds....................................................... 105
6.5 Conclusion .................................................................................................. 106
References............................................................................................................. 106
6
Fourteen-Year Assessment of a Permeable
Reactive Barrier for Treatment of Hexavalent
Chromium and Trichloroethylene
Richard T. Wilkin, Tony R. Lee, Mary Sue McNeil, Chunming Su,
and Cherri Adair
CONTENTS
6.1 Introduction
Interest in site-specific evaluations of permeable reactive barrier (PRB) performance is high, particularly with regard to issues relating to media longevity and hydraulic performance. As compared to a large number of full-scale
PRB applications around the world that have been constructed to remediate
groundwater contamination, few long-term data sets are available in the literature that provide PRB performance in detail. Higgins and Olson (2009)
recently conducted a life-cycle comparison of PRBs versus pump-and-treat
operations for groundwater remediation. On the basis of their analysis, it was
found that environmental impacts from PRBs are driven largely by material
production requirements and by energy usage during construction, while
for pump-and-treat systems environmental impacts are driven by operational energy demand. Higgins and Olson (2009) suggest that the minimum
longevity of granular iron PRBs required to outcompete pump-and-treat systems is 10 years. Consequently, a key aspect of life-cycle analysis and cost/
performance assessment is to have predictive tools that reasonably estimate
99
6.2 Site Background ......................................................................................... 100
6.3 Site Evaluation ............................................................................................ 101
6.4 Outcomes .................................................................................................... 102
6.4.1 Chromium....................................................................................... 102
6.4.2 Volatile Organic Compounds....................................................... 105
6.5 Conclusion .................................................................................................. 106
References............................................................................................................. 106
6
Fourteen-Year Assessment of a Permeable
Reactive Barrier for Treatment of Hexavalent
Chromium and Trichloroethylene
Richard T. Wilkin, Tony R. Lee, Mary Sue McNeil, Chunming Su,
and Cherri Adair
CONTENTS
6.1 Introduction
Interest in site-specific evaluations of permeable reactive barrier (PRB) performance is high, particularly with regard to issues relating to media longevity and hydraulic performance. As compared to a large number of full-scale
PRB applications around the world that have been constructed to remediate
groundwater contamination, few long-term data sets are available in the literature that provide PRB performance in detail. Higgins and Olson (2009)
recently conducted a life-cycle comparison of PRBs versus pump-and-treat
operations for groundwater remediation. On the basis of their analysis, it was
found that environmental impacts from PRBs are driven largely by material
production requirements and by energy usage during construction, while
for pump-and-treat systems environmental impacts are driven by operational energy demand. Higgins and Olson (2009) suggest that the minimum
longevity of granular iron PRBs required to outcompete pump-and-treat systems is 10 years. Consequently, a key aspect of life-cycle analysis and cost/
performance assessment is to have predictive tools that reasonably estimate
99