Watershed Assessment Section

We are responsible for monitoring and assessing the quality of Delaware's surface waters. Using a state-wide network of monitoring stations, we evaluate water quality at pre-determined frequencies for varying pollutants, according to the requirements we are working toward in a given watershed.

For instance, we conduct intensive monitoring to determine the amount of pollutants as part of the process of establishing Total Maximum Daily Load thresholds for our water bodies. On the other hand, if we are tracking water quality over a defined period of time (20 years, for example), then a station may only be monitored a couple of times a year.

Sediment quality monitoring is important, too, because many toxic contaminants bind to muds and clays. In areas where we suspect the presence of toxic chemicals, such as adjacent to a Superfund site on the Christina River, we monitor chemical levels in bottom sediments.

Many pollutants accumulate in plant and animal tissues, including people. We conduct bioaccumulation studies to assess the effects of pollutants on ecological and human health. Knowing that PCBs accumulate in trout, we conducted a study by measuring PCB levels in trout about to be released into Delaware's trout streams, and then several times after they were released into the wild. We were able to determine that ultimate PCB levels in the trout posed no risk to human health.

Bioassays are studies are studies involving aquatic organism exposures to various pollutants and other water quality conditions. When an industrial facility applies for a discharge permit renewal, the company may be required to conduct bioassays on various concentrations of their effluent. The results of the studies can then be used to set the conditions of the permit for the best levels of environmental protection.

We monitor the health of macroinvertebrates (mostly insect larvae, worms and clams living in or on the bottom of our streams, lakes and bays), as part of assessing the overall ecological health of our waters. Habitat quality is part of this overall health assessment. Our staff led a working group of allied professionals from the mid-Atlantic states, establishing new field sampling protocols, analytical software, and updated criteria for determining the overall health of organisms and their habitats.

Our soil scientists map Delaware's soils and conduct investigations on the potential effects of proposed projects and activities. Soil assessments are critical to our understanding of the potential for ground and surface water contamination. Chemical components of soils determine the vulnerability of water to materials applied to the land surface. We're working to estimate the amount of pollutants being generated by various current land uses and the levels of pollutant load reductions we can expect through the use of selected remedial actions.

Our wetlands scientists are mapping Delaware's wetlands and assessing the possible effects of proposed activities on our wetlands resources. We track wetlands gain and loss trends to assess the effectiveness of our protection efforts. Our scientists work with other agency staff, nonprofits, and the private sector. WIth EPA grant funding, staff prepared a Comprehensive Management Plan for Delaware's Non-Tidal (Freshwater) Wetlands.

We monitor permitting and other activities to ensure our wetlands are being adequately protected. Wetlands monitoring is used for ongoing trends and status.

Because shellfish can become unsafe for human consumption due to high levels of bacteria and viruses, we survey pollution sources for indicator bacteria levels. Data from our sampling stations is analyzed according to Interstate Shellfish Sanitation Program (ISSP) standards as a member of the Interstate Shellfish Sanitation Conference. The Conference facilitates program operating procedures and health standards development that protect shellfish consumers. We adopt the resulting standards into State regulations and ensure the compliance of Delaware's retail and wholesale seafood dealers. The U.S. Food and Drug Administration ensures conformance with National Shellfish Sanitation Program requirements and reviews our program annually.

High levels of bacteria or viruses mandate swimming area closures, and we are responsible for intensive water quality monitoring during the swimming season to help protect your health. We monitor all beach areas guarded by State and local governments. If we determine an area to be unsafe for human health, we advise the beach owner not to allow swimming. We work with other agencies to manage access to unsafe waters.

The federal Clean Water Act (CWA) requires that all states adopt water quality standards that are equal to or more protective than federal standards. We are also required to conduct a review every three years to make use of new data, information and federal standards. We've established significant goals for Delaware and report our water quality to the EPA on April 1st of every even numbered year. This report is used by the EPA to develop a Section 303(d) list of impaired waters.

If a water body appears on the Section 303(d) list, we have to establish a Total Maximum Daily Load (TMDL) for the pollutant(s) causing the impairment. The TMDL is the amount of pollutant that can be present in the water body and still have the water meet quality standards.

Our challenge is to develop legally defensible TMDLs for Delaware's water bodies. This involves using monitoring and other data to develop hydrodynamic and water quality models so that we can have predictive capabilities. We use these to run pollutant load reduction scenarios to determine whether water quality standards will be met at the TMDL levels we establish.

Pollution Control Strategies are used to implement TMDLs. We work with other agencies, nonprofits and private organizations to develop these strategies. For us, the most technically challenging aspect is estimating the pollution reductions we can expect from the strategies we implement.

We're also responsible for assessing the impacts of toxic chemical discharges on the aquatic environment under Section 303(l) of the CWA. Wastewater treatment plants that caused adverse water quality impacts were required to take remedial actions, including upgrading their treatment processes and/or improving discharge methods.

The Clean Water Act required that ponds and lakes be addressed in a phased manner, including watershed and pollution impact assessments, followed by development and implementation of remediation plans. Although the Clean Lakes Program was adequately funded in the late 1980s and early 1990s, Congress has since chosen to address lakes and ponds as part of the overall water quality management approach. Since funding for the program continues to be requested by many states, we need to be ready to gain funding should it become available in the future. In the meantime, we continue to use the data and assessments we collected during the time the program was actively funded.

Similar to the Clean Lakes Program, Section 320 of the Clean Water Act requires us to pay special attention to our estuaries through the National Estuary Program. We follow the Act's monitoring and assessment process to identify environmental issues, and have developed a Comprehensive Conservation and Management Plan. Our plan includes recommended actions needed to ensure estuary quality improvement. We used this process for the Inland Bays area are now tracking the aquatic system's response to the plan's implementation.

We work with two nonprofit organizations to recruit and train citizens to conduct water quality monitoring throughout Delaware. Our staff provide technical assistance and use the data gathered to asses the health of our aquatic environments. We'd like to take this opportunity to thank everyone involved in our programs for all of the hard work that helps make us successful.