Pocantico 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

Enterococcus is an EPA-approved fecal contamination indicator.

Samples taken by citizen scientists and processed at Sarah Lawrence College Center for the Urban River at Beczak, using methods and study designs that are consistent with Riverkeeper’s Hudson River and Community Science programs.



At just over nine miles long, the Pocantico River is one of the smallest tributaries monitored in Riverkeeper’s citizen science program. Although it is located in a predominantly suburban area, the Pocantico watershed includes a substantial portion of forested land. The watershed also features a number of historical features, such as the stone bridges of Rockefeller State Park, the restored Phillipsburg Manor estate and Sleepy Hollow Cemetery.

The Pocantico begins at Echo Lake, adjacent to the Saw Mill River Parkway in New Castle. From there the river’s flows through a patchwork of suburban and undeveloped areas, emptying into the Hudson at Kingsland Point Park in Sleepy Hollow. In addition to sampling along the main stem of the Pocantico River, citizen scientists collect samples in three Pocantico River tributaries.

Read Riverkeeper’s 2021 data summary for the Pocantico Watershed.



Riverkeeper partners with local residents to test the Pocantico River. Samples are processed at the Sarah Lawrence College Center for the Urban River at Beczak.

Sampling in this watershed in 2017 is funded by an EPA Urban Waters Small Grant. Sampling and sample processing procedures for this program are described in the program’s Quality Assurance Project Plan.

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