You could have downloaded AHGW 3.1 from our software library for free. The actual developer of the software is scientificsoftwaregroup. The most popular versions of the program 3.1, 3.0 and 2.4. The program lies within Photo & Graphics Tools, more precisely 3D Design.
From the developer:
Tools in the Groundwater Analyst will help you import data into your AHGW datamodel, manage key attributes, and visualize your data. With Groundwater Analyst you will be able to import a variety of datasets (wells, time series, cross sections, volumes) into your geodatabase, manage symbology of layers in ArcMap and ArcScene, map and plot time series, and create common products such as water level, water quality, and flow direction maps.
You may want to check out more software, such as FRED Optical Engineering Software or General Cadd Pro - FULL, which might be related to AHGW.