a guy i know built his spring house to collect water, insulating it with fiberglass somehow (i wasn't there and don't understand how it was all built exactly). there was still a heap of fiberglass trash in the muck that is maybe part of the overgrown pond or between it. i can't say i met any fish in that pond, but it was very overgrown. anyways, yeah. how bad is it? what to do besides pulling the trash out and waiting...?