On mobilization of lead and arsenic in groundwater in response to CO2 leakage from deep geological storage
If carbon dioxide stored in deep saline aquifers were to leak into an overlying aquifer containing potable groundwater, the intruding CO{sub 2} would change the geochemical conditions and cause secondary effects mainly induced by changes in pH In particular, hazardous trace elements such as lead and arsenic, which are present in the aquifer host rock, could be mobilized. In an effort to evaluate the potential risks to potable water quality, reactive transport simulations were conducted to evaluate to what extent and mechanisms through which lead and arsenic might be mobilized by intrusion of CO{sub 2}. An earlier geochemical evaluation of more than 38,000 groundwater quality analyses from aquifers throughout the United States and an associated literature review provided the basis for setting up a reactive transport model and examining its sensitivity to model variation. The evaluation included identification of potential mineral hosts containing hazardous trace elements, characterization of the modal bulk mineralogy for an arenaceous aquifer, and augmentation of the required thermodynamic data. The reactive transport simulations suggest that CO{sub 2} ingress into a shallow aquifer can mobilize significant lead and arsenic, contaminating the groundwater near the location of intrusion and further downstream. Although substantial increases in aqueous concentrations are predicted compared to the background values, the maximum permitted concentration for arsenic in drinking water was exceeded in only a few cases, whereas that for lead was never exceeded.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Earth Sciences Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 974271
- Report Number(s):
- LBNL-2722E; CHGEAD; TRN: US201007%%367
- Journal Information:
- Chemical Geology, Related Information: Journal Publication Date: 2009; ISSN 0009-2541
- Country of Publication:
- United States
- Language:
- English
Similar Records
Developing a robust geochemical and reactive transport model to evaluate possible sources of arsenic at the CO[subscript 2] sequestration natural analog site in Chimayo, New Mexico
Biogeochemical and reactive transport modeling of arsenic in groundwaters from the Mississippi River delta plain: An analog for the As-affected aquifers of South and Southeast Asia