When construction activities have the potential to affect the quality of streams or other bodies of water, the New York State Department of Environmental Conservation and other regulatory agencies often request sampling of macroinvertebrates as a way of describing existing water quality, or as a means of monitoring impacts. The term "macroinvertebrates" refers collectively to non-microscopic organisms such as worms, immature insects, snails, and clams that inhabit the bottoms of streams, lakes, and ponds. Of these organisms, immature insects such as mayflies, stoneflies, and caddisflies are especially sensitive indicators of water quality. Trout fishermen will recognize these insects as important components of good quality trout streams.

The NYS DEC uses in its own studies a method called "Rapid Biological Assessment of Streams" to sample and analyze macroinvertebrate data. The analysis of the macroinvertebrate data culminates in several numerical indices that reflect water quality. These indices take into consideration different characteristics of the macroinvertebrate community, such as species diversity and the pollution tolerance of certain groups of species.

TES uses this assessment method in its macroinvertebrate projects in New York State. Other states have their own guidelines or requirements for conducting such studies.