Wallkill River

Citizen Testing Sites

Water Quality Conditions by Location

Recent Samples Historical Statistics
Site Name (Watershed) Sample Date [i] Entero Count

Entero Count

Enterococcus (“Entero”) is a fecal indicating bacterium that lives in the intestines of humans and other warm-blooded animals.

[i] 4 Days Total Rain (in)

4 Days Total Rain (in)

The combined rainfall for the day of sampling, prior day, two days prior and three days prior. More than 1/4 inch is considered a “wet weather sample.”

[i] Number of Samples

Number of Samples

Total number of samples included in these calculations.

[i] Geometric

Geometric Mean

A measure of central tendency (a weighted average) used by NYS DEC and the US EPA to assess water quality. The geometric mean is defined as the nth root (where n is the number of samples) of the product of the Enterococcus measurements. A geometric mean over 30 fails the EPA criteria for safe primary contact.

[i] Maximum


The highest Enterococcus count we have recorded at this site (“>” indicates an unknown number greater than this number and reflects the upper limit of our scoring ability for this sample).

[i] Minimum


The lowest Enterococcus count we have recorded at this site (“<” indicates an unknown number less than this number and reflects the lower limit of our scoring ability for this sample).

Individual Entero Counts by Site

Note: multiple counts of the same value will overlap and appear as one dot.

Water Quality*

Acceptable (0–60) Beach Advisory (61+)

*Single sample thresholds;
Enterococcus count per 100mL

Prior Four Day Rainfall
(in inches)

Dry Weather (0–0.25) Wet Weather (0.25+)

Geometric Mean*

Acceptable (0–30) Unacceptable (31+)

*Weighted average of multiple
samples; Enterococcus count
per 100mL

The Wallkill River flows north from Sussex County, NJ into the Black Dirt Agricultural Region of Orange County, NY. The river channel is artificially straightened through that region, and then it resumes meandering near Goshen. From there it passes into Ulster County and follows the eastern side of the Shawangunk Ridge, eventually leading to New Paltz. The Wallkill River is dammed at several places, including in Rifton to form Sturgeon Pool, where Central Hudson Gas & Electric operates a hydroelectric power plant. Just downstream of the pool, the attenuated flow of the Wallkill joins Rondout Creek, which flows for approximately six more miles before emptying into the Hudson. Together, these two streams form the Hudson River Estuary’s largest tributary.

Read Riverkeeper’s 2021 data report for the Wallkill River Watershed.



Wallkill site selection meeting

Wallkill site selection meeting

Riverkeeper partners with the Montgomery CAC, Gardiner ECC, Wallkill River Watershed Alliance, and community scientists throughout the watershed to collect samples.

  • Waterway Classifications

  • Water Quality Data and Impairments

  • Wastewater Infrastructure

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