Once water quality standards are set and established as law in the Ohio regulatory code, OEPA workers then collect water samples and run a battery of analytical tests on them. A top priority is testing for traces of toxic substances. These include such heavy metals as lead, mercury, copper and chromium, volatile organic chemicals like PCBs and known cancer-causing agents. If so, we run more sensitive tests to determine specific concentrations. But determining water quality is more than tracking down toxics.
Field surveys are the final step in the process.
There, OEPA workers take a census of the different fish and invertebrate populations present, checking their scientific expectations against reality. Letterhos says studying water quality and population data in tandem is important to understanding the complex dynamics of the aquatic community. She says Ohio is making progress in ensuring the quality of its waters. The 1972 Clean Water Act is a big part of that. But in the last 20 years, we've put some pretty stringent requirements on those dischargers.