Here are this week’s quantitative E. coli concentration results from the 15 public access and recreational use sites located on the Main-stem, North Fork and South Fork of the Shenandoah River, and the Opequon Creek being tested by the Friends of the Shenandoah River. The water samples were collected on Thursday, June 27.
In a freshwater system, the data represents a snapshot of the water quality on the date, time, and under the conditions that the water sample was collected. E. coli levels are fluid, meaning that the concentration of E. coli changes. Such changes are influenced by many factors, including;
- changes in the volume of flow caused by
- local and regional rain events that flush contaminants from the land surfaces into the streams and rivers
- water withdrawal and drought
- runoff from urban, suburban, rural and agriculture lands
- illicit discharge, failing septic systems, contaminated groundwater
- wildlife, livestock, pets, and humans
Last night (Thursday, June 27) thunderstorms, with at times heavy rains, passed through Frederick, Clarke, Warren, and Shenandoah counties. This morning, Friday June 28, I collected water samples from the following locations to see what, if any, effect the rain may have had on the E. coli concentrations at these sites:
- Opequon Creek (FCOC)
- Main-stem of the Shenandoah River in Clarke County (FC01, FC05, and FC08)
- Main-stem of the Shenandoah River Warren (FW35 and FW 35 Mid) – did not observe evidence of rain at this site, such as standing puddles of water, yet surfaces, dampness
- Manassas Run (FW36) in Warren County – did not observe evidence of rain at this site, such as standing puddles of water, yet surfaces, dampness
- South Fork of the Shenandoah River in Warren County (FW14)
- North Fork of the Shenandoah River in Shenandoah County (FSDR and FSSP)
The E. coli concentration results for the water samples collected today will be posted tomorrow morning.