A framework for assessing risk reduction due to DNAPL mass removal from low-permeability soils

被引:59
作者
Freeze, RA [1 ]
McWhorter, DB [1 ]
机构
[1] COLORADO STATE UNIV, DEPT CHEM & BIORESOURCE ENGN, FT COLLINS, CO USA
关键词
D O I
10.1111/j.1745-6584.1997.tb00066.x
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Many emerging remediation technologies are designed to remove contaminant mass from source zones at DNAPL sites in response to regulatory requirements, There is often concern in the regulated community as to whether mass removal actually reduces risk, or whether the small risk reductions achieved warrant the large costs incurred. This paper sets out a proposed framework for quantifying the degree to which risk is reduced as mass is removed from DNAPL source areas in shallow, saturated, low-permeability media. Risk is defined in terms of meeting an alternate concentration limit (ACL) at a compliance well in an aquifer underlying the source zone, The ACL is back-calculated from a carcinogenic health-risk characterization at a downgradient water-supply well, Source-zone mass-removal efficiencies are heavily dependent on the distribution of mass between media (fractures, matrix) and phase (aqueous, sorbed, NAPL). Due to the uncertainties in currently available technology performance data, the scope of the paper is limited to developing a framework for generic technologies rather than making specific risk-reduction calculations for individual technologies. Despite the qualitative nature of the exercise, results imply that very high total mass-removal efficiencies are required to achieve significant long-term risk reduction with technology applications of finite duration. This paper is not an argument for no action at contaminated sites, Rather, it provides support for the conclusions of Cherry et al. (1992) that the primary goal of current remediation should be short-term risk reduction through containment, with the aim to pass on to future generations site conditions that are well-suited to the future applications of emerging technologies with improved mass-removal capabilities.
引用
收藏
页码:111 / 123
页数:13
相关论文
共 21 条
[1]   DISSOLUTION OF DENSE CHLORINATED SOLVENTS INTO GROUND-WATER .1. DISSOLUTION FROM A WELL-DEFINED RESIDUAL SOURCE [J].
ANDERSON, MR ;
JOHNSON, RL ;
PANKOW, JF .
GROUND WATER, 1992, 30 (02) :250-256
[2]  
[Anonymous], 1989, RISK ASSESSMENT GUID, VI
[3]  
Byl NN, 1993, ISOKINET EXERC SCI, V3, P139
[4]  
CHERRY JA, 1992, 3 INT C GROUND WAT Q
[5]  
CLAFF RE, 1993, HOUST HYDR C
[6]  
Cohen R. M, 1993, DNAPL site evaluation: SK Smoley
[7]   GROUND-WATER MODELING FOR RISK ASSESSMENT PURPOSES - USE OF A GUASSIAN-DISTRIBUTED TRANSPORT MODEL AND A BATCH FLUSH MODEL [J].
CUSHMAN, DJ ;
BALL, SD .
GROUND WATER MONITORING AND REMEDIATION, 1993, 13 (04) :162-172
[8]   HYDROGEOLOGICAL DECISION-ANALYSIS .1. A FRAMEWORK [J].
FREEZE, RA ;
MASSMANN, J ;
SMITH, L ;
SPERLING, T ;
JAMES, B .
GROUND WATER, 1990, 28 (05) :738-766
[9]  
FREEZE RA, 1992, HYDROGEOLOGICAL DECI
[10]  
HALLENBACK WH, 1986, QUANTITATIVE RISK AS