Fishable, Swimmable, Potable
in the shortest time possible
The goal of the Watershed Approach to Toxics Assessment and Restoration (WATAR) is to address current sources of contamination to waterways, along with those impacted historically by legacy pollutants, using a prioritized step-wise plan in order to achieve fishable, swimmable, and eventually potable water in all of Delaware’s waterways.
Fish and other aquatic life can be exposed to contaminants as they are released to the environment and accumulate in the water and sediment. The contaminants collect through the food chain as other animals prey upon the exposed fish, meaning that humans can be impacted if we eat the fish ourselves or eat the wildlife that eats the fish. Water quality data is utilized by DNREC and the Department of Health and Social Services to issue fish consumption advisories to inform the public of the risks of fishing in these areas.
The WATAR method looks at water bodies holistically to better identify the sources of contamination, eliminate those sources from the environment, reduce incidental exposure to toxic chemicals in the water, and protect public health. At the same time, this increases the public's ability to enjoy the environment and utilize Delaware's waterways for recreational activities without worrying about potential health risks.
Freshwater sources are treated and used to provide the public with potable drinking water. However, there are some substances that find their way into the water that are much harder to treat for and may be harmful if consumed. The data collected by WATAR is used to target sources more efficiently and remediate the areas more quickly than in the past. This results in cleaner freshwater sources, which translates into safer drinking water.
Updating Fish Advisories Using WATAR Data
Delaware's industrial past has contributed to, what are now considered, legacy pollutants. Pollutants like polychlorinated biphenyls (PCBs) are a big problem in Delaware, even though their production was banned in the 1970s because they are considered to be persistent, bioaccumulative, and toxic. This means that they do not break down in the environment and can accumulate in bodily tissues over time. Consuming fish from waters that are affected by PCB pollution can cause health risks to humans and other wildlife.
Fish consumption advisories inform the public that consuming fish from an impaired waterway may pose a health risk. If an advisory is necessary, it typically indicates that only a small amount of fish or no fish at all is recommended for human consumption. Advisories can be issued for more than one type of contaminant in a waterway, meaning that even if concentrations of one type of contaminant drop to safe levels, an advisory can still remain in an area for other substances. Data collected by WATAR has led to issuing less restrictive advisories in recent years for some waterways because of the remediation projects that have occurred.
Delaware River Mercury De-listing
One of the areas that has seen considerable improvement in contamination levels is the Delaware River. Between 2002 and 2012, dissolved mercury in the water decreased by approximately 70%. Over this same time period, mercury concentrations detected in striped bass in the Delaware River decreased by approximately 50%. These findings concluded that mercury is no longer a major concern in the River and removed the advisories associated with mercury. Fish from the Delaware River are still considered to pose threats to human health, mainly from PCBs. However, areas draining into the Delaware River have seen decreases in PCB contamination by approximately 50% from 2007-2015. Further reductions in PCB concentrations could result through the efforts of WATAR.
Page reviewed 3/6/19