NWIS Aquifers

[dblodgett-usgs]

We have some legacy aquifer codes that become problematic because of cross-state re-use of aquifers.

There is a file that tracks some significant unification.

We have to append state codes to some for them to be unique and have logic to figure that out.
Avoid anything that starts with 1. Names ending in "system" "erathum" or "rocks" should be excluded.

Should also add national aquifer reference associations.

Note that there are some deprecated codes that could be sameased -- think about avoiding those for now.