Groundwater flooding can occur when the water table rises due to (a) recharge to (or decreased abstraction from) aquifers with low storativity or (b) propagation of the rising river stages into permeable, river‐connected alluvial aquifers. The latter type was significant in 2013 in Alberta. A survey of 189 homes along the Elbow River in Calgary examined the basement flooding water characteristics and the initial route of floodwater entry. In homes where the initial route of entry was known, 88% were initially flooded by groundwater, and 12% reported exclusively groundwater flooding. Basement floor elevation was correlated with the severity of flooding (R2 = .61). Of the 19 surveyed homes located outside of the 100‐year overland flood zone, 47% were flooded by groundwater, indicating that groundwater flooding reaches beyond overland water‐flooded areas. Hydrogeological modelling demonstrated that propagation of increased river stage into the aquifer could reasonably have caused the observed groundwater flooding. Groundwater flood resilience strategies could include (a) monitoring groundwater levels in flood‐prone areas to differentiate sewer backup from groundwater flooding via wastewater collection systems and to provide groundwater flooding warnings, (b) specifying minimum home basement elevation with respect to river stages for specified flood return intervals, and (c) appropriate home construction.

Methane emission quantification from gas migration (GM) and surface casing vent flow (SCVF) is needed to support strategic methane reduction targets and mitigate explosion and groundwater quality risks. This paper assessed which of 451 990 Alberta oil and gas wells should have been (or will be) tested for SCVF and/or GM according to regulations, and compared the results with the provincial GM testing database. As of 2017, GM testing was required on 3.5%, and reported for 0.75%, of Alberta's energy wells. Similarly, SCVF testing was required on 58.2%, and reported for 6.2%, of all wells. An estimated 14.5% of all wells were legally abandoned before GM and SCVF testing regulations existed. All of the remaining wells will require SCVF testing prior to legal abandonment, and an estimated 32.9% to 75.5% of the total will not require GM testing before abandonment based on current regulations. The cumulative number of 'serious' GM reports that have remained open since submission has continuously been increasing each year, which contradicts the requirement for repair within 90 days, suggesting regulations are not enforced. The GM testing procedure is inadequate for quantitative testing. We conclude that fugitive methane emissions, and in particular gas migration, are not well constrained in Alberta.

Pseudomonas aeruginosa is capable of long-term survival in water, which may serve as a reservoir for infection. Although viable cell counts of PAO1 incubated in water remain stable throughout 8 weeks, LIVE/DEAD staining indicated a high proportion of cells stained with propidium iodide (PI). The proportion of PI-stained cells increased by 4 weeks, then decreased again by 8 weeks, suggesting an adaptive response. This was also evident in an observed shift in cell morphology from a rod to a coccoid shape after 8 weeks. Fluorescence-activated cell sorting (FACS) was used to recover PI-stained cells, which were plated and shown to be viable, indicating that PI-stained cells were membrane-compromised but still cultivable. PAO1 mid-log cells in water were labeled with the dsDNA-binding dye PicoGreen to monitor viability as well as DNA integrity, which demonstrated that the population remains viable and transitions towards increased dsDNA staining. Metabolic activity was found to decrease significantly in water by 4 weeks. The PAO1 outer membrane became less permeable and more resistant to polymyxin B damage in water, and the profile of total membrane lipids changed over time. Among the ~1400 transcriptional lux fusions, gene expression in water revealed that the majority of genes were repressed, but subsets of genes were induced at particular time points. In summary, these results indicate that P. aeruginosa is dormant in water and this adaptation involves a complex pattern of gene regulation and changes to the cell to promote long-term survival and antibiotic tolerance. The approach of P. aeruginosa incubated in water may be useful to study antibiotic tolerance and the mechanisms of dormancy and survival in nutrient limiting conditions.

Pseudomonas aeruginosa is capable of long-term survival in water, which may serve as a reservoir for infection. Although viable cell counts of PAO1 incubated in water remain stable throughout 8 weeks, LIVE/DEAD® staining indicated a high proportion of cells stained with propidium iodide (PI). The proportion of PI-stained cells increased by 4 weeks, then decreased again by 8 weeks, suggesting an adaptive response. This was also evident in an observed shift in cell morphology from a rod to a coccoid shape after 8 weeks. Fluorescence-activated cell sorting (FACS) was used to recover PI-stained cells, which were plated and shown to be viable, indicating that PI-stained cells were membrane-compromised but still cultivable. PAO1 mid-log cells in water were labeled with the dsDNA-binding dye PicoGreen® to monitor viability as well as DNA integrity, which demonstrated that the population remains viable and transitions towards increased dsDNA staining. Metabolic activity was found to decrease significantly in water by 4 weeks. The PAO1 outer membrane became less permeable and more resistant to polymyxin B damage in water, and the profile of total membrane lipids changed over time. None of the individual mutants within a library of ~2500 mapped, mini-Tn5-lux transposon mutants were found to have decreased survival in water. Among the ~1400 transcriptional lux fusions, gene expression in water revealed that the majority of genes were repressed, but subsets of genes were induced at particular time points. In summary, these results indicate that P. aeruginosa is dormant in water and this adaptation involves a complex pattern of gene regulation and changes to the cell to promote long-term survival and antibiotic tolerance. The approach of P. aeruginosa incubated in water may be useful to study antibiotic tolerance and the mechanisms of dormancy and survival in nutrient limiting conditions.