Grantee Research Project Results

2013 Progress Report: Diagnostic Monitoring of Biogeochemical Interactions of a Shallow Aquifer in Response to a CO2 Leak

EPA Grant Number: R834503
Title: Diagnostic Monitoring of Biogeochemical Interactions of a Shallow Aquifer in Response to a CO2 Leak
Investigators: Goldberg, David S. , Matter, Juerg M. , O'Mullan, Gregory , Stute, Martin , Takahashi, Taro
Institution: Columbia University in the City of New York
EPA Project Officer: Aja, Hayley
Project Period: December 1, 2009 through November 30, 2012 (Extended to November 30, 2014)
Project Period Covered by this Report: December 1, 2012 through November 30,2013
Project Amount: $899,997
RFA: Integrated Design, Modeling, and Monitoring of Geologic Sequestration of Anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water (2009) RFA Text |  Recipients Lists
Research Category: Drinking Water , Water

Objective:

The question addressed in this study is:  how does an elevated-level CO₂ concentration caused by a hypothetical leakage of CO₂ from deep injection reservoirs affect the chemical and microbiological conditions in a shallow aquifer?

Understanding the fundamental scientific processes resulting from CO₂ enrichment of aquifer water is the primary advance of the proposed work. In particular, we focus on determining the mobility of health-hazard chemical elements and the biogeochemical responses due to the CO₂ enrichment in target lithologies. The methodologies developed in this work will also be directly transferable to other sites affected by increased CO₂ levels induced from CO₂ sequestration in subterranean rock formations. 

The project investigates a shallow potable water aquifer system in sand/clay sequences of the Newark Basin group using laboratory and in situ experimental methods. Methods will involve extracting rock and water samples from a shallow aquifer and then conducting a series of geochemical and microbiological laboratory experiments using these samples. In situ injection and recovery experiments and groundwater logging tests will be conducted.  

Progress Summary:

The following activities were completed during the current project period, and major findings are briefly described, below:

1. Preliminary comparison and interpretation of geochemical data from 2011 and 2012 injection experiments using pumped-back fluids, including major ions, trace elements, pH, Eh, O₂ saturation, pCO₂, and total CO₂ in Well TW-3 samples. CO₂-enhanced aquifer water was injected into a fractured sedimentary rock aquifer and mineral dissolution and tracer element release were enhanced with increased acidity.

2. Complete analysis of geochemical collected during laboratory incubation experiments under controlled pH/pCO₂ and H₂ conditions, abiotic and biotic conditions, and chemical analysis of drill cuttings and fluid samples from TW-3 using ICP-MS, IC and GC, as described in the QAPP.

3. Aquifer chemistry was altered after CO₂ injection, evidenced by similar patterns observed in both 2011 and 2012 injections:

   1. Elemental release rates were dependent on pCO₂ (pH) and affected by redox condition.
   2. Minor deterioration of groundwater quality was observed under a hypothetical CO₂ leakage scenario.

4. Complete bio-informatic analysis of the 16S rRNA gene sequence libraries from both 2011 and 2012 injection experiments to characterize microbial community composition before and after injections, including: total microscopic cell counts, enrichment culture Most Probable Number (MPN) enumeration, and preliminary 454 sequencing of DNA for 16S rRNA gene characterization for bacteria and archaea, yielding approximately 140,000 sequences for characterization of the microbial community.

5. Aquifer bacterial concentrations increased upon CO₂ introduction, then return to low concentrations in tandem with metals release, as evidenced by cell and DNA concentrations in both injection experiments.

6. Aquifer microbial community structure altered after CO₂ injection, as evidenced by similar patterns observed in both injections:

   1. Background aquifer samples were dominated by Proteobacteria, but after CO₂ injection Verrucomicrobia, Chrenarchaeota and Bacteroidetes have increased representation in the sequence library.
   2. Bacterial and archaeal communities shift significantly post-injection, revealing a successional response to CO₂ presence and subsequent metals release:
      1. Hydrogenophaga and Sphingobium, dominant in background samples, decrease in representation in the sequence library significantly post-injection.
      2. Dechloromonas, Verrucomicrobia, Thermosphaera and Sulfophobococcus become dominant in sequence library post-injection.
      3. Metal-reducing bacteria including Geothrix, Geobacter, Syntrophobacterales and Desulfovibrionales respond to CO₂ injection by sharp initial increases in library representation, then gradual return to background levels.
      4. Iron and sulfur oxidizers such as Ferroplasma, Acidothiobacillus and Ferrimicrobium, including acid tolerant genera, increase in representation in sequence library immediately post-injection, whereas Leptospirillium do not.
      5. Methanogens including Methanomicrobia and Methanobacteria increase in library representation post-injection.

7. Compilation of laboratory and field-test results for scientific publications (see Publications/Presentations).

8. Compilation of laboratory and field test results for the project review meeting at EPA Headquarters in Washington DC, January 2013 (see Publications/Presentations).

9. Preparation of Project Web Access site (see Web Access). 

Future Activities:

We anticipate the following activities to be accomplished during the upcoming period (Year 5):

1. Acquire groundwater logging and hydrogeologic testing data in TW-4 and compare results to adjacent well TW-3.
2. Complete analysis and research papers on geochemical and microbiological data collected during laboratory incubation experiments under controlled pH/pCO₂ and H₂ conditions.
3. Complete analysis and research papers on geochemical and microbiological data comparisons of 2011 and 2012 injection experiments.
4. Present results in special conference session(s) focused on geochemical and microbiological monitoring and assessment of subsurface carbon sequestration injections.
5. Complete distribution of data and results via project web site.
6. Post scientific publications of results on project web site.

Journal Articles:

No journal articles submitted with this report: View all 18 publications for this project

Supplemental Keywords:

Sequestration, pollution prevention, metals, microbiology, groundwater

Progress and Final Reports:

Original Abstract

2010 Progress Report

2011 Progress Report

2012 Progress Report

Final Report