Our original plans called for the elevator to stop at the cellar floor, This meant that the elevator pit would have to be excavated a minimum of 6 feet deeper than the finished cellar floor elevation. Our geotechnical surveys and borings reported that the water table might be encountered at approximately 14 feet below the first floor slab elevation.
In these photos, Pepe encountered the water table even higher than expected, at approximately 12 feet below finished first floor elevation, We called the elevator company, Thyssen, and they confirmed our concern that placing the elevator pit in the water table was not recommended.
Based on the geography of the site, and its proximity to sea level and the East River, any pumping scenario would likely require large redundant pumps that would be constantly pumping. Essentially we would be trying to pump out the East River.
We decided to redesign to eliminate the elevator stop to the cellar due to safety and maintenance issues. There would now be nothing in the cellar but mechanical functions, with no tenant-accessible spaces in the cellar anymore.
The water table is evident in these photos, indicated by the white sand mixed with the water.