Water Quality > Tributary and Waterfront Data > Saw Mill River > Yonkers- Saw Mill River, Van der Donck Park

Yonkers- Saw Mill River, Van der Donck Park

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

115 Samples taken

Sample Date [i] Enterococcus Count

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.

QualityRain, day of (in)Prior Day2 Days Prior3 Days Prior Rain4 Days Total Rain
10/18/201875Beach Advisory0.
10/04/20181835Beach Advisory0.
10/04/20181835Beach Advisory0.
09/20/2018131Beach Advisory0.
09/20/2018131Beach Advisory0.
08/23/2018670Beach Advisory0.
08/23/2018670Beach Advisory0.
08/09/20182064Beach Advisory0.
08/09/20182064Beach Advisory0.
08/02/2018990Beach Advisory0.
07/26/20183784Beach Advisory0.
07/26/2018537Beach Advisory0.
07/12/2018231Beach Advisory0.
06/28/2018>24196Beach Advisory0.
06/28/20187556Beach Advisory1.
06/14/201875Beach Advisory0.
06/14/201875Beach Advisory0.
05/31/2018221Beach Advisory0.
10/26/2017563Beach Advisory0.
10/12/2017616Beach Advisory0.
09/14/2017183Beach Advisory0.
08/03/2017373Beach Advisory0.
07/06/201797Beach Advisory0.
06/15/2017109Beach Advisory0.
06/08/2017185Beach Advisory0.
05/25/20172755Beach Advisory0.
10/27/2016270Beach Advisory0.
09/22/201685Beach Advisory0.
09/01/2016960Beach Advisory0.
08/25/2016355Beach Advisory0.
08/18/2016510Beach Advisory0.
08/11/2016457Beach Advisory0.
08/04/2016280Beach Advisory0.
07/21/201673Beach Advisory0.
07/14/20161480Beach Advisory0.
07/07/2016216Beach Advisory0.
06/30/2016320Beach Advisory0.
06/23/2016120Beach Advisory0.
06/16/2016570Beach Advisory0.
06/02/2016320Beach Advisory0.
05/26/2016488Beach Advisory0.
05/19/2016360Beach Advisory0.
10/08/2015987Beach Advisory0.
10/01/201511199Beach Advisory0.
09/24/2015275Beach Advisory0.
09/17/2015556Beach Advisory0.
09/10/2015>24196Beach Advisory0.
09/03/2015203Beach Advisory0.
08/27/2015323Beach Advisory0.
08/20/2015364Beach Advisory0.
08/13/2015573Beach Advisory0.
08/06/2015209Beach Advisory0.
07/30/2015588Beach Advisory0.
07/23/2015173Beach Advisory0.
07/16/2015301Beach Advisory0.
07/09/20153255Beach Advisory0.
07/01/201511199Beach Advisory0.
06/25/2015355Beach Advisory0.
06/18/2015528Beach Advisory0.
06/11/2015546Beach Advisory0.
06/04/2015816Beach Advisory0.
05/28/20153873Beach Advisory0.
05/21/2015650Beach Advisory0.
10/02/2014272Beach Advisory0.
09/25/20141145Beach Advisory0.
09/18/2014160Beach Advisory0.
09/11/2014211Beach Advisory0.
09/04/2014241Beach Advisory0.
08/28/2014331Beach Advisory0.
08/14/20142489Beach Advisory0.
08/07/2014166Beach Advisory0.
07/31/2014448Beach Advisory0.
07/24/2014488Beach Advisory0.
07/17/20141071Beach Advisory0.
07/10/2014450Beach Advisory0.
07/02/2014295Beach Advisory1.
06/26/20144786Beach Advisory0.
06/19/20142595Beach Advisory0.
06/12/2014613Beach Advisory0.
06/05/2014>24196Beach Advisory0.
05/29/2014443Beach Advisory0.
05/22/20144352Beach Advisory0.
10/03/2013332Beach Advisory0.
09/26/2013216Beach Advisory0.
09/19/2013203Beach Advisory0.
09/12/2013426Beach Advisory1.
08/29/2013689Beach Advisory0.
08/22/2013521Beach Advisory0.
08/15/2013820Beach Advisory0.
08/08/2013776Beach Advisory0.
08/01/2013480Beach Advisory0.
07/25/20132300Beach Advisory0.
07/18/2013241Beach Advisory0.
07/11/2013>24196Beach Advisory0.
07/02/201319863Beach Advisory0.
06/27/2013216Beach Advisory0.
06/20/2013226Beach Advisory0.
06/13/2013573Beach Advisory1.
06/06/2013437Beach Advisory0.
05/23/2013187Beach Advisory1.

Entero Count (fecal indicator) and Rainfall Correlation

115 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 and processed at laboratories that aren't directly affiliated with Riverkeeper, using methods and study designs that are consistent with Riverkeeper's Hudson River and Citizen Testing programs.

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:

This site is located in downtown Yonkers a few blocks from the Hudson River, in the section of the Saw Mill River that was daylighted in 2011. The area is now a park and it is used by Groundwork Hudson Valley for educational programs. Partners: Groundwork Hudson Valley (sponsor), Sarah Lawrence College Center for the Urban River at Beczak (lab analysis); Site Coordinators: Jerry Blackstone and Robert Hothan

Agencies Responsible:

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

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