On a warm and sunny day in May, the 2018-2019 cohort took to the field!  Along with Centre County Pennsylvania Senior Environmental Corp member Genie Robine, a retired biology teacher, the students returned to the abandoned well in State Game Lands #103.  Working in three teams, the students performed nettings to collect macroinvertebrates from the riffles in Grindstone Gap, in Wallace Run below Grindstone Gap, and in two tributaries draining from a beaver dam and the well into Grindstone Gap.  Macroinvertebrates indicate stream quality as many of these organisms prefer to live in cold, fast moving waters with high levels of dissolved oxygen.  Although the students collected sensitive organisms such as mayfly and stonefly nymphs from most of the waters, the overall water quality scores ranked poor for the two muddy bottom tributaries and fair for the rocky bottom Grindstone Gap and Wallace Run streams.  To compare with surveys collected in October 2018 (much farther downstream on Wallace Run), the richness in diversity of sensitive and tolerant organisms increases downstream.