A Bacteria Standard — For this website 235 cfu/100ml of E. coli is used as the maximum concentration criteria for primary water contact recreation. This standard was used in the past and was developed over years of study. What is it for the water to meet the criteria for primary contact  recreation ?  It means that  fewer than  36 out of 1000 will suffer illness within 2 days of swimming. It does not mean that all swimmers are completely protected  from illness.  The risk of illness increases with E. coli density. see precautions. Virginia has no  bacteria standard for freshwater primary water contact recreation.

CFU/100ml — colony forming units per 100 milliliters

cfs — cubic feet per second, USGS standard flow reporting units

cfsm — cubic feet per second per square mile (of the basin at the gage). Flow yield reporting units.

DCR — Virginia department of Conservation and recreation.

DEQ — Virginia Department of Environmental Quality.

FOSR — Friends of Shenandoah River

k cfs — Thousands of cubic feet per second,  National Weather Service flow reporting units

Normal flow –– For this website Normal Flow is when rivers flow in cubic feet per second is less than the drainage area of the site in square miles. Normal Flow in The Rivers occurs 80% of the time  during the swimming season (5/15 to 9/15).  Normal Flow is the maximum median flow during the swimming season.

Primary water contact recreation — 9VAC25-260-5. Definitions – any water-based form of recreation, the practice of which has a high probability for total body immersion or ingestion of water (examples include but are not limited to swimming, water skiing, canoeing and kayaking).

Secondary contact recreation — means a water-based form of recreation, the practice of which has a low probability for total body immersion or ingestion of waters (examples include but are not limited to wading, boating and fishing). Virginia has not designated any stream as secondary contact.

Swimming season — For this website the swimming season is May 15 to September 15. During that period the temperature of The Rivers water is usually above 70 F°

The Rivers — Means the North Fork Shenandoah River, South Fork Shenandoah River, and the Shenandoah River .

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