2 NARRATIVE ACCOMPLISHMENTS OverviewThis report is a summary final report of the research undertaken at the University of Idaho (UI) over the past four years under DOE EMSP award DE-FG07-02ER63500. This work was performed collaboratively with investigators at the Idaho National Laboratory (INL) and Northwind Inc., who will provide separate summaries of their portions of the interdisciplinary project. The research centered on studies of the subsurface environment of the Snake River Plain Aquifer (SRPA) of the Test Area North (TAN) site at the INL in southeastern Idaho. Through this interdisciplinary effort, UI, INL, and Northwind, Inc. investigated coupled biogeochemical processes implicit in conceptual and mathematical models that describe trichloroethylene (TCE) co-metabolism in complex subsurface strata. Our team accomplished the following:• Investigated the microbial ecology of the SRPA related to known TCE cometabolizers.• Obtained evidence of biogenic methane in the SRPA that can sustain methanotrophic cometabolism of TCE.• Developed conceptual and mathematical models for natural attenuation at TAN and other DOE sites.• Used specific enzyme activities to detect TCE co-metabolic potential in SRPA microbes.• Acquired stable carbon isotope fractionation data for contaminants that demonstrate enhanced bioremediation of TCE.• Gained extensive field experience in subsurface microbiology, bioremediation, and design and operation of in situ bioreactors.• Two students received graduate degrees through their participation on the project.• One postdoctoral scientist received training through participation on the project.The following publications and presentations co-authored by members of the University of Idaho group were partially or completely made possible through the funding provided under award DE-FG07-02ER63500. Graduate Students TrainedTwo graduate students were trained during the project: J. L. Sebat, PhD and D. P. Erwin, MS. Postdoctoral Scientists TrainedOne postdoctoral scientist received experience during the project: Dr. Janice L. Strap SPECIFIC ACCOMPLISHMENTS Specific Accomplishment 1: find molecular markers of the methane monooxygenase (MMO) particulate form (pMMO) within the Test Area North (TAN) site of the Eastern Snake River Plain Aquifer (ESRPA) in IdahoIn this study we used primers specific for conserved regions of the pmoA gene of methane monooxygenase (MMO) particulate form (pMMO), the mmoX gene of MMO soluble form (sMMO), and the amoA gene of ammonia monooxygenase (AMO). We used the polymerase chain reaction (PCR) to amplify a variety of genes from whole community (metagenomic) DNA obtained directly from the aquifer. Based on these functional gene analyses, bacteria related to the type II methanotroph Methylocystis dominated both free-living and attached ESRPA communities. Type I sequences that grouped nearest to Methylobacter and Methylomonas were only obtained from the freeliving community. Sequences similar to the amoA gene associated with ammoniaoxidizing bacteria (AOB) most closely ma...