United States Environmental Protection Agency Office of Research and Development National Exposure Research Laboratory Research Abstract Government Performance Results Act Goal: Clean and Safe Water and Sound Science Significant Research Findings: Landscape Indicators for Pesticides Study- Mid-Atlantic Coastal Streams Scientific Problem There is a growing interest and need for factual information about the and Policy Issues environmental condition of streams and watersheds at local, state, and national levels. Until now, producing this information has been expensive and often beyond the price range of those who could benefit most. The Landscape Indicators for Pesticides Study-Mid-Atlantic Coastal Streams (LIPS-MACS) demonstrates the "landscapes approach," which extends the information gained from statistically selected, ground-based monitoring sites by using remotely-sensed data from satellites and applying principles from ecology, hydrology, and geography. For example, coarse scale features such as elevation and topography constrain finer scale features such as watersheds to behave in a similar manner. The study focuses on pesticides and nutrients in Mid-Atlantic freshwater, coastal streams. These parameters were selected because excess pesticides and nutrients in the environment can cause a variety of ecological and human-health effects. The occurrence of pesticides in streams and groundwater has implications for Food Quality Protection Act (FQPA) regulatory processes. Nutrients are principal pollutants causing water quality problems according to the Clean Water Act 305b listings for states nationwide. Total Maximum Daily Load values for these pollutants are being developed for many streams. The landscapes approach has the potential to rank all watersheds in an area (not just those sampled) based on consistent quantitative criteria and to evaluate land use management options using projected future land use scenarios. Research Approach The LIPS-MACS study is the first to utilize monitoring data collected specifically for the purpose of developing landscape indicators. The study approach incorporates a study design that enables data to be collected for two purposes simultaneously, 1) to provide data to develop landscape indicator statistical models and 2) to characterize regional conditions and compare subregions within the study area. For the Mid-Atlantic Coastal Streams, the objectives were to a) design a field study for first-order streams and watersheds stratified by National Exposure Research Laboratory — October 2001 ------- hydrogeologic subregions, and within each subregion provide a range of land use conditions; b) select specific watersheds and associated sampling locations; c) sample streams and nearby habitat one time in the spring, 2000; d) analyze the data to develop landscape indicator statistical models and to estimate pesticide and nutrient concentrations to characterize the entire study area; and e) use the landscape indicator models to estimate pesticide and nutrient concentrations for each of the first-order watersheds in the Mid-Atlantic Coastal Plain, incorporating these results into analyses developed in conjunction with local, state, and federal stakeholders. Results and For the LIPS-MACS study, an unequal probability, stratified random Implications sampling design was used to select a network of 174 headwater streams that provided both a gradient across percent developed land use/land cover conditions and a statistically representative set of sampling sites for the Coastal Plain region. Each hydrogeologic framework subregion was represented by 23 - 25 sites. Water samples were collected in Spring, 2000 during baseflow conditions for all streams and analyzed for selected pesticides, pesticide degradates, nutrients, and major ions; in addition, benthic community and habitat assessments were performed and sediment samples were collected during the same time period. To date, the LIPS-MACS study has successfully developed landscape indicator statistical models for herbicides, nitrate + nitrite, and chloride in small, fresh, headwater streams for the Mid-Atlantic Coastal Plain, while simultaneously providing data to characterize regional conditions. The landscape indicator statistical models were developed using landscape and soil metrics and stepwise regression. These models show that increased human land use is associated with increased dissolved concentrations of herbicides, nutrients, and chloride for these streams. Low concentrations of pesticides were present in over 80% of the streams. The presence of herbicides in streams during baseflow conditions indicates these chemicals are widespread in the shallow ground water of the Coastal Plain. This shallow ground water is sometimes used for drinking water in rural areas. Concentrations of nitrogen and phosphorus exceeded the EPA-recommended ecoregional nutrient levels of 0.71 mg/L for total nitrogen for 39% of the streams and 0.03 mg/L for more than 66% of the streams respectively. These nutrient levels were developed by EPA to provide guidance to States and Tribes for the protection and propagation of aquatic life and recreation. Finally, comparison of the values for nitrate + nitrite measured within each of the hydrogeologic subregions showed significant differences between some subregions. This suggests that different mitigation strategies may be needed for different areas to achieve the same degree of water quality protection. National Exposure Research Laboratory — October 2001 ------- Research This study is a collaborative research project funded by the U.S. Collaboration and Environmental Protection Agency's Office of Research and Publications Development and the U.S. Geological Survey. Within EPA's Office of Research and Development, individuals are participating from the National Exposure Research Laboratory Divisions in Las Vegas, Nevada; Cincinnati, Ohio; and Athens, Georgia; and the National Health and Environmental Effects Laboratory in Corvallis, Oregon. In the U.S. Geological Survey, individuals are participating from the Maryland, Delaware, and District of Columbia District, Water Resources Division. Pitchford, A.M., Neale, A.C., Ator, S.W., Ebert, D.W., Van Remortel, R.D., Denver, J.M., Olsen, A., Subramanian, B., Kutz, F.W., Jones, K.B., Landscape Approach for Assessing Stream Condition: Landscape Indicators for Pesticide Study Mid-Atlantic Coastal Streams, (TIP # 01-126, APM 130, Journal Article) A. Pitchford, PO. submitted to Environmental Monitoring and Assessment, September 2001. Kutz, F.W., Garibay, R., West, F., Bottimore, D., Perryman, T., and Orochena, S. Maryland Agriculture and Your Watershed. EPA 903-R-00-009. Pitchford, A.M., Denver, J.M., Olsen, A.R., Ator, S.W., Cormier, S., Nash, M.S., and Mehaffey, M.H. Testing Landscape Indicators for Stream Condition Related to Pesticides and Nutrients: Landscape Indicators for Pesticides Study for Mid-Atlantic Coastal Streams (LIPS-MACS). EPA/600/R- 00/087 Ator, S.W., Denver, J.M., Pitchford, A.M. Developing landscape indicator models for pesticides and nutrients in streams of the Mid-Atlantic Coastal Plain (USGS Fact Sheet FS-157-00) A. Pitchford PO. Future Research Statistical analysis of the LIPS-MACS data is continuing, and analyses of the benthic macroinvertebrate and sediment data will be incorporated into the process. The landscape indicator models will be applied to all at the 10,000 first-order watersheds in the Coastal Plain to predict their current condition and to identify watersheds at risk. Landscape change scenarios will be used to investigate the effects of urbanization. A similar study in the Midwest is in the planning stages, and a study in California will follow. National Exposure Research Laboratory — October 2001 ------- Information Contacts for Questions and inquiries concerning the LIPS-MACS research can be Additional directed to Ann Pitchford for landscape indicators; Judith Denver for the hydrogeologic framework, water quality sampling and water chemistry; and Susan Cormier for benthic macroinvertebrate sample collection and analysis. Questions and inquiries can be directed to: Ann M. Pitchford US EPA, Office of Research and Development National Exposure Research Laboratory Las Vegas, NV 89193 Phone: 702/798-2366 E-mail: pitchford.ann@epa.gov Judith M. Denver US Geologic Survey, Maryland-Delaware-DC District Dover, DE 19901 Phone: 302/734-2506 E-mail: jmdenver@usgs.gov Susan M. Cormier US EPA, Office of Research and Development National Exposure Research Laboratory Cincinnati, OH 45268 Phone: 513/569-7995 E-mail: cormier.susan@epa.gov Federal funding for this research was administered under EPA interagency agreement DW 149385351 with the U.S. Geological Survey and under EPA off-site contracts 68-W5-0011 and 68-D-00-267 with Lockheed Martin Environmental Services. National Exposure Research Laboratory — October 2001 ------- |