Summary and Interpretation of Discrete and Continuous Water-quality Monitoring Data Mattawoman Creek Charles County Maryland 2000-11

<p>Discrete samples and continuous (15-minute interval) water-quality data were collected at Mattawoman Creek (U.S. Geological Survey station number 01658000) from October 2000 through January 2011 in cooperation with the Charles County (Maryland) Department of Planning and Growth Management the Maryland Department of the Environment and the Maryland Geological Survey. Mattawoman Creek is a fourth-order Maryland tributary to the tidal freshwater Potomac River; the creek's watershed is experiencing development pressure due to its proximity to Washington D.C. Data were analyzed for the purpose of describing ambient water quality identifying potential contaminant sources and quantifying nutrient and sediment loads to the tidal freshwater Mattawoman estuary. Continuous data collected at 15-minute intervals included discharge derived from stage measurements made using a pressure transducer as well as water temperature pH specific conductance dissolved oxygen and turbidity all measured using a water-quality sonde. In addition to the continuous data a total of 360 discrete water-quality samples representative of monthly low-flow and targeted storm conditions were analyzed for suspended sediment and nutrients. Continuous observations gathered by a second water-quality sonde which was temporarily deployed in 2011 for quality-control purposes indicated substantial lateral water-quality gradients due to inflow from a nearby tributary representing about 10 percent of the total gaged area upstream of the sampling location. These lateral gradients introduced a time-varying bias into both the continuous and discrete data resulting in observations that were at some times representative of water-quality conditions in the main channel and at other times biased towards conditions in the tributary. Despite this limitation both the continuous and discrete data provided insight into the watershed-scale factors that influence water quality in Mattawoman Creek.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p>