This project predicts the safety and quality of groundwater in selected neighborhoods around Lowry Landfill in Aurora, Colorado, a Superfund site since 1984. A plume of liquid waste has, in recent years, been slowly spreading underground northwest from the landfill, posing a risk to both waterways and groundwater. The latter is of particular concern since Lowry Landfill sits atop the Denver Aquifer, which provides the metro area with the bulk of its fresh water.
I used GIS to map existing and prospective neighborhoods downstream of the plume. First I overlaid them on both a map of Arapahoe County and a map of the Denver Aquifer. For a measure of vulnerability of groundwater, I used soil data overlaid on neighborhood maps and measured using the DRASTIC system: groundwater Depth, Recharge, Aquifee, Soil, Topography, Impact of vadose, and hydraulic Conductivity). For locating upcoming housing developments, I overlaid with a “Master Plans” dataset from the City of Aurora.
I have found that overall, the soil of the land around the plume site and my selected housing developments was a loam with silty, clay, or less often sandy elements, and a maximum slope of 5 percent. These two factors help keep the DRASTIC score low– silt and clay are smaller particles than sand, and therefore provide soil some protection from liquid waste seepage, and slopes smaller than 6 percent limit runoff. These factors make groundwater risk less than expected, but they do not eliminate it, especially with movement of the Lowry underground plume already occurring, and climate change expected to override these built-in protections.
Any disruption of the bedrock in this area will result in immediate contamination of the Denver Aquifer. Construction must include limits on building footprint and basement depth, and fracking must be prohibited.