Arsenic concentration in groundwater

Boyle, D.R., Turner, R.J.W. and Hall, G.E.M. (1998) Anomalous arsenic concentrations in groundwaters of an island community, Bowen Island, British Columbia. Environmental Geochemistry and Health, 20(4), 199-212. 

Many investigations of groundwater quality have identified variable and often extremely high arsenic concentrations. NicoUi et al. (1989) found arsenic concentrations in groundwaters from Cordoba in the range 6-11,500 p,gL (median 255 p,gL ). Smedley et al. (2002) found... 

Table 2. Frequency distribution of arsenic concentrations in groundwater from Quatemaiy alluvial/deltaic aquifers in three study areas of Bangladesh (well depths respectively <50 m Chapai Nawabganj <100 m Faridpur <150 m Lakshmipur data source BGS and DPHE, 2001)...

Table 9. Frequency distribution of arsenic concentrations in groundwater samples from northern Punjab (from Iqbal, 2001)...

There is much speculation about the reasons for the high arsenic concentrations in groundwaters in Bangladesh and elsewhere. It is useful in these discussions to consider three aspects of the problem the source of the arsenic, its mobilization and the extent of its present and past transport or movement in the groundwater flow. 

Despite this, a substantial proportion of U.S. groundwaters [42% in the Frey and Edwards (31) study] have arsenic concentrations below 0.5 [tg/L. In addition, the variability of arsenic concentrations in groundwaters suggests that arsenic is differentially mobilized from various source materials under different environmental conditions. Thus the speciation of arsenic in the solid phase and its susceptibility to leaching by contacting porewater as well as mechanisms for the sequestration of arsenic from the aqueous to solid phases must be considered. 

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