Water Quality

The surface waters of Antietam Creek are generally characterized as being of good quality, although the area is showing some impacts from human activities. Primarily agricultural, wooded, or rural residential land users surround the creek and its tributaries within the battlefield; however, upstream municipalities and the neighboring town of Sharpsburg may also impact the quality of the park’s water resources. These are problems that affect many natural areas in the face of intensive agricultural practices and increasing development.

Park resource managers have identified the following specific threats to the quality of Antietam’s surface and groundwater resources:

1) Agricultural runoff or nutrients and erosion into park surface waters possibly causing eutrophication or sedimentation.

2) Groundwater contamination from old septic systems in Sharpsburg.

3) Sewage discharge from upstream municipalities.

4) Storm water runoff from the streets of Sharpsburg.

Many of the same hazards that threaten the waters of Antietam National Battlefield have led to a decline in the health of the Chesapeake Bay. One of the most serious threats is the excessive discharge of nutrients such as nitrogen and phosphorus into the tributaries of the Bay, resulting in the eutrophication of many waterways. This process depletes water of oxygen, which in turn kills fish and other plants and animals. The National Park Service joined the Chesapeake Bay Program (a regional agreement to reduce nitrogen and phosphorus levels entering the Bay) in 1994 with a commitment to aid in the creation of streamside riparian buffer zones throughout these tributaries. These buffers are vegetated areas that stretch 35 feet or more from the water’s edge and may be fenced off to prevent livestock from entering the water. Riparian buffers will help achieve both the nutrient reduction and the habitat restoration goals put in place by the program. In addition to the establishment of these zones, park staff also works with cooperating farmers on agricultural nutrient management issues. As a means of examining the effects of these programs, Antietam’s Natural Resources Division has initiated a water quality-monitoring plan. Thirteen times a year, several water quality parameters are measured at six different locations within the park. Park staff record the water temperature, depth, pH, dissolved oxygen content, and nitrogen and phosphorus levels for each of these sites. Using computer software, data is recorded and analyzed to determine impacts of park activities on water quality.