EPA appears to be using ESRI’s ArcIMS 9.2 OGC connectors to publish OGC WMS/WFS services of their WATERS data.
See below for threads
that mention the limitations and issues with working with these semi-standard
services from ESRI.
http://openlayers.org/pipermail/users/2007-May/001571.html
http://www.mail-archive.com/users@openlayers.org/msg04240.html
– Little thread that I started a while ago to check on support for pure ESRI
services.