Water Quality > Tributary and Waterfront Data > Saw Mill River > New Castle- Tertia Brook tributary

New Castle- Tertia Brook tributary

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

22 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.

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
06/22/2017 638 Beach Advisory 0.0 0.0 0.0 0.9 0.9
06/08/2017 75 Beach Advisory 0.0 0.0 0.2 0.1 0.3
05/11/2017 98 Beach Advisory 0.0 0.0 0.0 0.0 0.0
10/27/2016 160 Beach Advisory 0.0 0.0 0.0 0.0 0.0
10/13/2016 310 Beach Advisory 0.0 0.0 0.0 0.0 0.0
09/29/2016 11200 Beach Advisory 0.0 0.0 0.4 0.0 0.4
09/15/2016 30 Acceptable 0.0 0.0 0.0 0.0 0.0
09/01/2016 280 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/18/2016 690 Beach Advisory 0.0 0.0 0.4 0.0 0.4
08/04/2016 180 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/14/2016 1550 Beach Advisory 0.0 0.0 0.0 0.0 0.0
06/30/2016 6130 Beach Advisory 0.0 0.0 0.3 0.3 0.7
06/16/2016 420 Beach Advisory 0.0 0.0 0.0 0.0 0.0
06/02/2016 420 Beach Advisory 0.0 0.0 0.0 0.6 0.6
05/19/2016 50 Acceptable 0.0 0.0 0.0 0.0 0.0
10/08/2015 464 Beach Advisory 0.0 0.0 0.0 0.0 0.0
09/24/2015 110 Beach Advisory 0.0 0.0 0.0 0.0 0.0
09/10/2015 8664 Beach Advisory 0.2 0.0 0.0 0.0 0.2
08/27/2015 638 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/13/2015 14136 Beach Advisory 0.0 0.0 0.6 0.0 0.6
07/30/2015 959 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/16/2015 3654 Beach Advisory 0.0 0.0 0.4 0.0 0.4

Entero Count (fecal indicator) and Rainfall Correlation

22 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:

The Tertia Brook is the first named tributary to enter the Saw Mill River. This site is located where the Tertia Brook enters the parking lot of the Chappaqua Public Library. Upstream of here, the brook flows from its headwaters through residential areas.

Agencies Responsible:

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

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