Streamflow and Water-Quality Monitoring in Montgomery County, Maryland
A cooperative program between USGS and Montgomery County Department of Environmental Protection
By Brenda Majedi, Cherie Miller, Anthony Modugno, Bill Davies
Introduction
The USGS started two water-quality monitoring studies during water year 2007 in cooperation with the Montgomery County Department of Environmental Protection. One study station is located on Rock Creek in Rock Creek Park, Washington, D.C., and commenced December 2006. The other study station is located on Paint Branch on the property of the U.S. Army Adelphi Laboratory Center in Adelphi, Maryland, and commenced July 2007. The broad objectives of both studies are to assess the water quality of each stream by characterizing nutrients, suspended sediment, and bacteria concentrations during base-flow and stormflow conditions.
Methods used at Rock Creek and Paint Branch
Discrete samples are collected over a range of hydrologic conditions.
Base-flow samples are collected monthly from the stream cross section using USGS protocols, including integrated equal-width (EWI) sampling.
Stormflow samples are collected using an automatic sampler to capture multiple samples over the storm hydrograph. About twelve storms per year will be collected depending upon hydrologic conditions.
Several samples are collected at each site per year for quality-control purposes, and include field blanks, replicates, and comparisons of EWI to automatic samplers.
- Constituents monitored include
- Nutrients: total Kjeldahl nitrogen, total phosphorus Nitrite/nitrate
- Sediment: suspended sediment and total suspended solids
- Bacteria: fecal coliform, enterococci, and E. coli (only fecal coliform at the Rock Creek site)
The Washington Suburban Sanitary Commission (WSSC) laboratory performs the analysis for all constituents except the suspended sediment, which is analyzed by the USGS Sediment Laboratory, in Louisville, Kentucky.
Rock Creek Water-Quality Monitoring
Background
Rock Creek is an important stream resource to Montgomery County in Maryland and to the National Capital Region. Parts of Montgomery County, Maryland and Washington, D.C. drain into Rock Creek. Rock Creek drains to the Potomac River and thus eventually to the Chesapeake Bay Estuary. The entire river is valued as a recreational resource and provides important habitat to aquatic organisms. Land use in the Rock Creek watershed is predominantly a mixture of agricultural and urban/suburban. Continued urban and agricultural development in the Rock Creek Basin has negatively affected water and sediment quality in the river.
Study Objectives, Rock Creek
Location of USGS surface-water
station 01648000 (Sherril Drive)
and water-quality station 01648010
(Joyce Road) within Rock Creek Park,
Washington, D.C.
1. Establish and maintain a water-quality monitoring station on Rock Creek at Joyce Road (USGS Station ID 01648010).
2. Establish flow relation between Sherril Drive and Joyce Road stations.
3. Collect discrete samples for nutrients, suspended-sediment, and bacteria (fecal coliform) concentrations, using integrated equal-width sampling for base flow and an automatic sampler to capture stormflow events.
4. Publish water-quality data for inclusion in the USGS National Water Information System (NWIS) database and in the Annual Data Report of the MD-DE-DC Water Science Center.
Boxplot showing the distribution of fecal coliform bacteria concentrations collected at Rock Creek (USGS station 01648010), December 2006 through July 2007.
Examples of real-time stream stage and water temperature at Rock Creek, Joyce Road. Note the storm event on Sept 28, 2007.
Base-flow sampling off bridge
at Rock Creek at Joyce Road site.
Automatic samplers located at both sites collect
discrete stormflow samples over the storm hydrograph.
Paint Branch Water-Quality Monitoring
Background
Paint Branch is a major tributary to the Anacostia River and lies within the urban/suburban corridor in central Maryland and Washington, D.C. The watershed extends into Prince George's and Montgomery Counties in Maryland; the Anacostia River drains to the Potomac River. The study station is located on the border between Montgomery and Prince George's Counties, and is on the property of the U.S. Army Adelphi Laboratory Center. The Paint Branch watershed has seen major increases in urbanization, and this is the most dominant influence on the stream's water quality.
Study Objectives, Paint Branch
Location of USGS water-quality station 01649190
Paint Branch at College Park, MD
1. Establish and maintain a water-quality monitoring station on Paint Branch at College Park, MD (USGS Station ID 01649190).
2. Collect discrete samples over a range of flow conditions for nutrients, suspended-sediment, and bacteria (fecal coliform) concentrations, using integrated equal-width sampling for base flow and an automatic sampler to capture stormflow events.
3. Collect continuous (every 15 minutes) water-quality parameters that will be displayed in real time on the USGS webpage: water temperature, specific conductance, pH, dissolved oxygen, and turbidity.
4. Deliver water samples to the WSSC laboratory in Laurel, Maryland, and document quality-assurance practices and certifications of the WSSC laboratory.
5. Publish water-quality data for inclusion in the USGS National Water Information System (NWIS) database and in the Annual Data Report of the MD-DE-DC Water Science Center.
Instrumentation at the Rock Creek station includes a pressure transducer
to measure stream stage, and a CR10X data logger and modem to transmit data
to the USGS real-time water information page.
Examples of real-time turbidity and dissolved oxygen at Paint Branch.
Base-flow sampling at Paint Branch site.
Multiparameter datasonde at Paint Branch provides continuous
measurements (every 15 minutes) of water temperature,
specific conductance, pH, dissolved oxygen, and turbidity.
Data are displayed in real time on the USGS webpage.
For More Information
For real time water-quality and streamflow data: http://waterdata.usgs.gov/md/nwis/rt
Or for further information contact:
Director
USGS MD-DE-DC Water Science Center
5522 Research Park Drive
Baltimore, Maryland
443-498-5500
http://md.water.usgs.gov/
