Low flow, warm water, and nutrients are the ingredients for algae blooms. These pictures were taken today, Wednesday, July 28, at various sites as identified in the photos.
ADVISORY posted by the Virginia Department of Health – Out of an abundance of caution, an advisory has been issued for the North Fork Shenandoah River due to the detection of cyanobacteria toxins within mat material at two sites; Bethel Road (near the intersection of Rt. 644) and at Strasburg, near S Holliday Street (Rt. 648). While the cyanobacteria mats at those two discreet locations are wide-spread, they were not observed throughout the entire ~5 mile stretch of this river segment. Weather and other environmental factors can cause rapid changes in water quality and cause mat material to shift in location. People and pets should avoid contact and accidental ingestion of cyanobacteria mats throughout the river. The drinking water plant at Strasburg is working with state and county officials to ensure the continued safety of drinking water and will continue to monitor for algal toxins at the plant intake.
https://www.vdh.virginia.gov/content/uploads/sites/178/2021/07/NF-Shenanodah-HAB-Status-Report-7.23.21_final.pdf
Once again the E. coli levels of >2,419.6 measured at site FW36, Manassas Run upstream of the confluence with main-stem Shenandoah River, just upstream of the public boat landing, on Wednesday, July 21, 2021, exceeded the previous Virginia water-quality standard threshold of 235 E. coli colony forming units per 100 mL of water sample for primary recreational use.
FOSR 2021 Summer Quantitative E. coli Concentration Results through 07.21.2021
The water level in the North Fork and South Fork of the Shenandoah River dropped again this week. Also seeing algae blooms at many of the sites we collect water samples from.
Potentially harmful algae bloom in the North Fork of the Shenandoah River near Bethel Road area of Strasburg in Shenandoah County. The Lord Fairfax Health District of the Virginia Health Department is cautioning people not to swim in that area until the results of an algae test come in later this week. The algae blooms discovered at the Bethel Road area of Strasburg could be cyanobacteria, which “has the ability to put out a neurotoxin.”
On Wednesday, July 14, 2021, at site FW36, Manassas Run upstream of the confluence with main-stem Shenandoah River, just upstream of the public boat landing, the E. coli level was 435.2 MPN of E. coli colony-forming units per 100 mL. This level exceeded the previous Virginia water-quality standard threshold of 235 E. coli colony forming units per 100 mL of water sample for primary recreational use.
The amount of flow in the North Fork, South Fork, and Main-stem of the Shenandoah River has been steadily decreasing. The recent localized rain events have not been enough to recharge the water supply.
FOSR 2021 Summer Quantitative E. coli Concentration Results through 07.14.2021
It is appreciated that some folks are picking up and bagging the garbage others have carelessly left behind. However, the garbage also needs to be hauled away. VA DWR does not have the resources to maintain the boat launches on a weekly bases. The stockpiling of garbage is attracting wildlife, including insects, and causing unpleasant odors.
Please reach out to the local Board of Supervisors to remind them of this ongoing issue, make positive suggestions to resolve the trash problem.
At one of the sites that we collected water samples at yesterday, Wednesday July 07, 2021 the E. coli level exceeded the previous Virginia water-quality standard threshold of 235 E. coli colony forming units per 100 mL of water sample for primary recreational use.
FW36 – Manassas Run upstream of the confluence with main-stem Shenandoah River, just upstream of the public boat landing, 1,413.6 MPN of E. coli colony-forming units per 100 mL
FOSR 2021 Summer Quantitative E. coli Concentration Results through 07.07.2021
To provide you with the most current E. coli levels in preparation of your holiday plans, I collected water samples at 7 sites yesterday, Friday, July 2. The E. coli levels at FW36 Manassas Run and FW35MID Shenandoah River both at Morgan’s Ford low water bridge in Warren County VA, increased from when the water samples were collected on Thursday, July 1. On both days the E. coli levels at these two sites exceeded the previous Virginia water-quality standard threshold of 235 E. coli colony forming units per 100 mL of water sample for primary recreational use.
07.02.2021 FW36 – Manassas Run upstream of the confluence with main-stem Shenandoah River, just upstream of the public boat landing, >2,419.6 MPN of E. coli colony-forming units per 100 mL.
07.01.2021 FW36 – Manassas Run upstream of the confluence with main-stem Shenandoah River, just upstream of the public boat landing, 275.5 MPN of E. coli colony-forming units per 100 mL
07.02.2021 FW35MID –Main-stem Shenandoah River at Morgan’s Ford low H2O bridge at mid width of the River, 920.8 MPN E. coli colony-forming units per 100 mL
07.01.2021 FW35MID –Main-stem Shenandoah River at Morgan’s Ford low H2O bridge at mid width of the River, 290.9 MPN E. coli colony-forming units per 100 mL
FOSR 2021 Summer Quantitative E. coli Concentration Results through 07.02.2021