What are LEL & SEL values?
A. These benchmarks are based upon chronic, long-term impacts of contamination to benthic organisms. The Lowest Effect Level (LEL) is a level of sediment contamination that can be tolerated by the majority of benthic organisms. The Severe Effect Level (SEL) is that at which pronounced disturbance of the sediment-dwelling community can be expected. This is the concentration that would be detrimental to the majority of the benthic community. If a single parameter equals or exceeds the LEL, it is anticipated that material represented by that sample may have an adverse effect of some benthic resources. If all analytes are below LELs, no significant effects are predicted. If any single analyte equals or exceeds its SEL, the representative material is considered highly contaminated and is anticipated to have significant adverse impacts on benthic resources. LELs and SELs are based upon the Screening Level Concentration approach using benthic community observations, and are calculated through
