Watershed Conservation Plan - Destination Erie

Figure 5.19. Mercury concentrations measured in precipitation at various parts of Pennsylvania (from
Lynch et al. 2005b).
were frequently detected "urban" pesticides. Many of the chemicals were found at concentrations sufficiently
high to be considered threats to aquatic life and human health (Myers et al. 2000). None of the sites sampled
by Myers et al. (2000) were within the Pennsylvania Lake Erie watershed study area.
Buckwalter et al. (1996) of the U.S. Geological Survey tested for the occurrence of herbicides in three
different agricultural tile drain systems within the Pennsylvania Lake Erie watershed in late summer of 1989,
during the time when these drainage systems provide the primary source of local streamflow. The water from
all three systems (two in the Girard-Fairview area and one near North East) contained detectable levels of
either simazine or atrazine, indicating that "some tile drains are moving low concentrations of herbicides from
the ground-water system to surface water" (Buckwalter et al. 1996). Considering the large portions of the
study area used for intensive agriculture, and the too frequent use of lawn-care chemicals in developed areas,
it would seem prudent to conduct more extensive analyses of pesticides in streams draining agricultural and
urban areas of our watershed to evaluate their potential adverse effects on aquatic life and public health.
Scientists and environmental agencies have recently begun to evaluate a variety of "unregulated
contaminants" categorized as PPCPs (pharmaceuticals and personal care products) and EDCs (endocrine
disrupting compounds), which are widely disseminated in the environment and have been poorly evaluated
regarding potential harmful effects (Skadsen et al. 2004; USEPA 2006h). Skadsen et al