FOREWORD ACKNOWLEDGEMENTS EXECUTIVE SUMMARY I. INTRODUCTION Background ........Geography ........Economics Purpose and Scope II. WATER QUALITY PRIMER 1998 – 2004: A Region in Flux ........Hydrologic condition ........Agriculture ........Population Growth and Development III. ANALYSIS AND RESULTS ........Analytical Methods Overall Results and Parameter Descriptions ........Nutrients ................Total Phosphorus ................Nitrogen ........................Ammonia-nitrogen ........................Nitrate-nitrogen ........Fecal Coliform Bacteria Overall Results by Year Watershed Analysis ........Anderson Run ........Lunice Creek ........Lost River ........Mill Creek ................Comparing North and South Mill Creeks ........North Fork ........South Branch ........South Fork ........Outer Run The Big Picture IV. DISCUSSION ........What the trends mean ........Total Phosphorus ........Ammonia ........Nitrate ........Fecal coliform bacteria ........A question of source ........USGS Potomac Headwaters Study V. SUMMARY LITERATURE CITED APPENDIX 1 Field and Lab Methods APPENDIX 2 Summary Statistics APPENDIX 3 Trend Analyses