National Capital Region Network 2005 - 2006 Water Resources Monitoring Report

Norris, Marian; Schmit, John; Pieper, James

In 2005, the National Capital Region Inventory and Monitoring Network (NCRN) initiated a long-term water quality and quantity monitoring program, funded in part by the Water Resources Division. The program is carried out through monthly sampling at more than 50 sites within 10 of the NCRN parks. This report summarizes and analyzes the preliminary Water Chemistry and Nutrient Dynamics findings through 2006. Parks monitored for this report include Antietam National Battlefield, Catoctin Mountain Park, Chesapeake and Ohio Canal National Historical Park, Harpers Ferry National Historical Park, George Washington Memorial Parkway, Manassas National Battlefield Park, Monocacy National Battlefield, National Capital Parks - East, Prince William Forest Park, Rock Creek Park, and Wolf Trap National Park for the Performing Arts. The streams monitored are all part of the Potomac River Watershed. The Potomac is the second largest drainage of the nine river basins that form the 64,000 square mile Chesapeake Bay watershed. Water chemistry is important to maintaining a healthy habitat for many aquatic organisms, wildlife, and humans. Water Quality can provide insights into overall system productivity, shift species abundances and distributions, and alter nutrients cycles. Water quality parameters such as pH, specific conductance, dissolved oxygen, and temperature are good measurements that provide an overview of water quality. Water quality monitoring is required to comply with relevant environmental legislation and NPS mandates and to evaluate potential stressors in NCRN waters. One of the major findings, though not unexpected, of this program is that phosphorus levels at all sites exceed the ecological eutrophication threshold nearly 100% of the time. A majority of the sites also showed elevated levels of nitrate that exceeded the established ecological threshold. Nitrate and phosphorus are nutrients of primary concern in efforts to improve the ecological condition of the Potomac River and the Chesapeake Bay. Sources for these nutrients are not fully identified. Ammonia levels rarely exceeded the established thresholds. Repeated exceedances occurred at single sites, suggesting that there is a localized upstream source. A number of the sites sampled exhibited levels of dissolved oxygen that were below the threshold that supports stream life, occasionally for months at a time. Several of the same sites also possessed measures of specific conductance that exceeded levels known to stress the biological stream community. Acid neutralizing capacity at all sites never exceeded the established threshold. This indicates that currently none of the parks or their streams are in danger of succumbing to acidification. Very few exceedances of pH measurements were found throughout the sampling in 2005 and 2006, often at a very localized scale, temporally and spatially. The table on the following page summarizes the data collected, at the park level. All collected measurements at each site were utilized to provide a mean and range for the parameters detailed in this report.

National Capital Region Network 2005 - 2006 Water Resources Monitoring Report

Series

Collections