Landfill 1A was the first Commission landfill to be closed in a modern way, using technologies they devised which are now commonplace, such as digging a deep channel around the entire base of the landfill to isolate it from surrounding groundwater, and pumping the collected leachate out through a series of wells, sending it by pipeline to the local sewage treatment plant. Other innovations at this landfill include building a pond on top of it. The pond has since collapsed, as the landfill has settled considerably over the past thirty years. The Commission worked with an artist, Nancy Holt, to turn the landfill into a sculpture and celestial observatory called Sky Mound, although only a few of her ideas were implemented.