Water Quality
Water Quality > Pocantico River > Sleepy Hollow- Rockefeller Brook tributary

Sleepy Hollow- Rockefeller Brook tributary

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Physical/Chemical Data

Physical, chemical and biological properties of the surface water that are measured continuously while the patrol boat is underway.

Entero Count (fecal indicator) and Rainfall

50 Samples taken

Sample Date [i] Enterococcus Count
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Entero Count

Enterococcus (“Entero”) is a fecal indicating bacterium that lives in the intestines of humans and other warm-blooded animals. It is the EPA preferred indicator for sewage contamination.

Quality Rain, day of (in) Prior Day 2 Days Prior 3 Days Prior Rain 4 Days Total Rain
Sort Sort Sort Sort Sort Sort Sort Sort
09/19/2024 31 Acceptable 0.0 0.0 0.0 0.0 0.0
08/22/2024 560 Beach Advisory 0.0 0.0 0.0 0.1 0.1
06/13/2024 130 Beach Advisory 0.0 0.0 0.0 0.0 0.0
05/16/2024 4160 Beach Advisory 0.2 0.3 0.1 0.0 0.5
10/19/2023 20 Acceptable 0.0 0.0 0.0 0.0 0.0
09/21/2023 115 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/24/2023 30 Acceptable 0.0 0.0 0.0 0.0 0.0
07/27/2023 780 Beach Advisory 0.0 0.0 0.4 0.0 0.4
06/15/2023 1118 Beach Advisory 0.0 0.6 0.0 0.1 0.7
05/18/2023 20 Acceptable 0.0 0.0 0.0 0.0 0.0
10/20/2022 41 Acceptable 0.0 0.0 0.0 0.0 0.0
09/15/2022 291 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/18/2022 147 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/22/2022 934 Beach Advisory 0.0 0.3 0.0 0.0 0.3
10/21/2021 20 Acceptable 0.0 0.0 0.0 0.0 0.0
09/23/2021 55 Acceptable 0.0 0.0 0.0 0.0 0.1
07/15/2021 253 Beach Advisory 0.0 0.0 0.0 0.2 0.2
06/17/2021 193 Beach Advisory 0.0 0.0 0.0 0.1 0.1
10/19/2019 405 Beach Advisory 0.0 0.0 0.0 2.9 3.0
09/21/2019 134 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/17/2019 86 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/20/2019 1430 Beach Advisory 0.0 0.0 0.3 1.1 1.4
06/15/2019 96 Beach Advisory 0.0 0.0 0.7 0.0 0.7
05/18/2019 20 Acceptable 0.0 0.0 0.0 0.0 0.1
10/27/2018 2310 Beach Advisory 0.3 0.0 0.0 0.0 0.3
09/15/2018 74 Beach Advisory 0.0 0.0 0.0 1.1 1.1
08/18/2018 19863 Beach Advisory 0.5 1.4 0.0 0.0 1.9
06/16/2018 157 Beach Advisory 0.0 0.0 0.0 0.0 0.0
05/19/2018 204 Beach Advisory 0.2 0.0 0.3 0.9 1.4
10/21/2017 48 Acceptable 0.0 0.0 0.0 0.0 0.0
09/16/2017 770 Beach Advisory 0.0 0.0 0.4 0.0 0.5
08/19/2017 1986 Beach Advisory 0.0 0.4 0.0 0.0 0.4
07/15/2017 2420 Beach Advisory 0.0 0.5 0.4 0.0 0.8
06/17/2017 2420 Beach Advisory 0.0 0.2 0.0 0.0 0.2
05/20/2017 57 Acceptable 0.0 0.0 0.0 0.0 0.0
10/08/2016 178 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/13/2016 1986 Beach Advisory 0.0 0.4 0.0 0.3 0.7
07/09/2016 2420 Beach Advisory 0.0 0.0 0.4 0.0 0.4
06/11/2016 328 Beach Advisory 0.0 0.0 0.0 0.3 0.3
05/14/2016 32 Acceptable 0.0 0.2 0.0 0.0 0.2
09/05/2015 50 Acceptable 0.0 0.0 0.0 0.0 0.0
08/01/2015 575 Beach Advisory 0.0 0.7 0.0 0.0 0.7
07/04/2015 613 Beach Advisory 0.0 0.0 0.0 0.6 0.6
06/06/2015 488 Beach Advisory 0.1 0.0 0.0 0.0 0.1
05/02/2015 20 Acceptable 0.0 0.0 0.0 0.0 0.0
09/06/2014 517 Beach Advisory 0.1 0.0 0.0 0.0 0.1
08/02/2014 921 Beach Advisory 0.2 0.2 0.0 0.0 0.4
07/05/2014 2420 Beach Advisory 0.0 0.1 1.4 1.5 3.0
06/07/2014 281 Beach Advisory 0.0 0.0 0.5 0.2 0.6
10/06/2012 1046 Beach Advisory 0.0 0.0 1.2 0.3 1.5

Entero Count (fecal indicator) and Rainfall Correlation

50 Samples taken

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+)

Enterococcus is an EPA-approved fecal contamination indicator.

Samples taken by citizen scientists trained by Riverkeeper, and processed on the Riverkeeper vessel, according to the 2014 Quality Assurance Project Plan.

Rainfall data comes from wunderground.com. Wet weather is a common trigger of fecal contamination.

What do the Numbers Mean?

Water Quality scoring is based on the 2012 Recreational Water Quality Criteria from the US Environmental Protection Agency (EPA) for safe swimming. Learn More

About this location:

The Rockefeller Brook rises from three small ponds and flows through a mostly forested and agricultural area before joining the Pocantico River in the Rockefeller State Park Preserve.

Agencies Responsible:

Westchester County Dept. of Health: 914-813-5000; NYSDEC Region 3: 914-428-2505