My thesis adviser Steve Mrozowski has lots of experience identifying
parasites, as does Leslie Driscoll, who is also  one of his graduate
students at UMass/Boston.  I've just begun a lab project counting and
identifying roundworms from soil samples taken from privies found during
the excavation of the Central Artery/Third Harbor Tunnel project here in
Boston.  It's not terribly difficult once you know what to look for, and
you don't need tons of expensive equipment.