Ohio’s Surface Water Monitoring Approach: Sampling Designs for Streams, Rivers, Wetlands and Lakes
Ohio Environmental Protection Agency, Columbus, Ohio
Ohio Environmental Protection Agency (Ohio EPA) conducts stream and river sampling in support of the Total Maximum Daily Load (TMDL) program. To ensure adequate coverage across a spatial scale within a watershed, sampling sites are generally chosen with a geometric sampling design. Increased demands on resources have led to randomized site selection for smaller streams within the geometric approach of large study areas. This randomization takes into account similar land use practices within a given area for streams of a specific drainage area (<10mi 2).
Ohio EPA’s wetland program completed its first watershed based survey in 2004. Wetland sampling sites were chosen using a probabilistic survey approach. Development of wetland tiered aquatic life uses (TALU), and incorporation of these into water quality standards (WQS) has precluded additional watershed based surveys at this time. Summer 2008 surveys will focus on mitigation wetland evaluation through vegetative and amphibian sampling.
Ohio EPA’s lakes program was resurrected in 2004 after diminished resources eliminated lake sampling in the mid-1990s. An inland lakes workgroup has been redeveloping the program focusing on sampling design since March 2006. Sampling in 2007 will involve participation in the National Lakes Survey.