Some pesticides were detected in one or more samples.  This graph shows two of the most frequently detected in butter clams, by location: Aldrin and heptachlor epoxide.  Most of these concentrations are higher than the screening levels.  However, the calculated risk factors once again fall within EPA's safe range, relieving concerns about these chemicals.

Note the concentrations detected even at Crab Bay, the reference area where impacts from humans are minimal.