Trends in water quality in Youngs Branch, Manassas National Battlefield Park
Schmit JP and Brolis A. 2021. Trends in water quality in Youngs Branch, Manassas National Battlefield Park. Natural Resource Report. NPS/NCRN/NRR—2021/2307. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/nrr-2287442
The National Capital Region Inventory and Monitoring Network has monitored water quality in Youngs Branch in Manassas National Battlefield Park since 2005. Measurements taken at the stream include acid neutralizing capacity, discharge, dissolved oxygen concentration, pH, salinity, specific conductance, total nitrogen concentration, total phosphorus concentration and water temperature. This report assesses water quality in the stream in terms of trends over time, seasonal changes and relationships with discharge. Additionally, we find that several water quality characteristics frequently fall in ranges that can negatively affect aquatic life. These include high specific conductance, low values of dissolved oxygen, and seasonal drying of the stream. Other characteristics rarely (salinity, total nitrogen, total phosphorus) or never (acid neutralizing capacity, pH, temperature) fall outside of an acceptable range. Several water quality characteristics follow a seasonal pattern with low water temperatures, high dissolved oxygen concentrations and high discharge in the winter months followed by high temperatures, low dissolved oxygen and low discharge in the summer. High discharge is also associated with low pH and acid neutralizing capacity, perhaps due to differences in chemistry between rainwater and ground water. The only long-term trends detected were small increases in dissolved oxygen and decreases in pH. Seasonal drying of the stream and lack of dissolved oxygen are likely related to overheating of the stream during the winter months. Youngs Branch flows through several small ponds and these should be investigated to determine if they are impeding water flow or are locations of depleted dissolved oxygen. Chronic high specific conductance is likely due to sediment and pollutants in the stream. The small tributaries entering the park should be checked to determine if any of them have particularly elevated specific conductance.
- Type
- Published Report
- Authors
- Schmit, John; Brolis, Andrejs
- Date of Issue
- 2021-09
- Publisher
- National Park Service
- DOI
- 10.36967/nrr-2287442
- Units
- MANA , NCRN , NRSS
- Keywords
- NCRN, Water Quality Monitor, Water Quality Monitoring