The aquifers and waterways around the Lake Calumet area of south Chicago, IL, USA have been affected by a century of intensive industrial waste dumping. Steel slag in particular was used as infilling to claim most of the Calumet Wetlands for industrial and residential development. Since the prohibition and cessation of these disposal activities, a growing body of research has recorded the environmental and health effects of the infill, particularly where interactions between slag minerals and rainwater produces extremely alkaline groundwater (pH ≥13). Atmospheric carbon dioxide interacting with these calcium hydroxide-rich slag fluids produces massive precipitation of a loose, white calcite flocculent, filling some ponds and waterways to the point that they are easily recognizable from aerial photographs. One such site on the bank of the Indian Creek canal, which drains Wolf Lake into the Grand Calumet River, hosts a peculiar microbiome in the oxygenated layers of the calcite sediment. One bacterium, representing up to 85% of the waterline microbiome, belongs to the genus Serpentinomonas, recently described from a natural hyperalkaline system: a serpentinizing spring at the Cedars, CA, USA. The extreme alkalinity and dearth of carbon sources other than the calcite flocculent makes this anthropogenic pollution site strikingly similar to sites of natural serpentinization, close enough that the hyperalkaliphilic Serpentinomonas can thrive. Efforts have been made to culture the Serpentinomonas bacterium found at Indian Creek, but the particular growth conditions make culturing experiments slow and unpredictable. Culture-independent, sequence-based methods have yielded a 90% complete draft genome for the Indian Creek Serpentinomonas, and combined application of bioinformatics and selective culturing should yield new insights into bacterial adaptations to highly alkaline freshwater environments.