Changes

The longitudes and latitudes were stored as numeric, rather than real, but this doesn't seem to the source of the problem as it has suitable precision[https://www.postgresql.org/docs/current/datatype-numeric.html]. Instead the problem seems to be in the loading and unloading of tables through the \COPY command.  Regardless, we have decimal degrees to six decimal places from Google Maps, which is equivalent to a staggering 11cm of accuracy at the equator. See http://wiki.gis.com/wiki/index.php/Decimal_degrees.