Groundwater ecosystems are globally widespread yet still poorly understood. We therefore investigated contextual and environmental data characterizing 138 groundwater samples from Canadian groundwater ecosystems. The chemical, physical, gas, isotopic, and microbiological measurements were taken from aquifers in the Canadian Prairie between 2015 and 2020. The study area comprised 14 major aquifers and a geographic area of ~210.000 km2. The goal of the study was to understand the links between the biogeochemistry and microbial ecology of groundwater ecosystems in diverse geological settings on a broad spatial scale. Details concerning methods, results and conclusions can be found in the associated publication by Ruff et al. 2023.