Water Quality
Water Quality > Hudson River Estuary Data > Rockland County & Westchester County Sites > Furnace Brook

Furnace Brook

Furnace Brook
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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

108 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
10/17/2023 <10 Acceptable 0.0 0.0 0.0 0.6 0.6
09/19/2023 31 Acceptable 0.0 1.0 0.2 0.1 1.3
08/22/2023 20 Acceptable 0.0 0.0 0.0 0.0 0.0
07/18/2023 10 Acceptable 0.0 0.0 1.4 0.2 1.6
06/27/2023 1130 Beach Advisory 1.3 1.6 0.0 0.3 3.1
05/02/2023 197 Beach Advisory 0.0 0.2 2.2 1.6 4.0
10/11/2022 20 Acceptable 0.0 0.0 0.0 0.0 0.0
09/11/2022 31 Acceptable 0.0 0.0 0.0 0.0 0.0
08/20/2022 63 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/16/2022 10 Acceptable 0.0 0.0 0.0 0.0 0.0
06/14/2022 20 Acceptable 0.1 0.0 0.0 0.0 0.1
05/24/2022 10 Acceptable 0.0 0.0 0.0 0.0 0.0
10/29/2021 717 Beach Advisory 0.0 0.0 0.0 3.4 3.4
09/14/2021 216 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/17/2021 933 Beach Advisory 0.0 0.0 0.0 0.1 0.1
07/20/2021 323 Beach Advisory 0.0 0.1 0.3 0.9 1.3
06/08/2021 10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/18/2021 75 Beach Advisory 0.0 0.0 0.0 0.0 0.0
10/15/2020 408 Beach Advisory 0.0 0.0 0.3 0.3 0.6
09/19/2020 41 Acceptable 0.0 0.0 0.0 0.0 0.0
08/15/2020 313 Beach Advisory 0.0 0.0 0.0 0.0 0.0
07/15/2020 63 Beach Advisory 0.0 0.0 0.0 0.0 0.0
06/17/2020 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/27/2020 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
10/09/2019 30 Acceptable 0.1 0.1 0.2 0.0 0.4
09/11/2019 20 Acceptable 0.0 0.0 0.0 0.0 0.0
08/07/2019 97 Beach Advisory 0.0 0.0 0.0 0.2 0.2
07/10/2019 272 Beach Advisory 0.0 0.0 0.0 0.0 0.0
06/06/2019 <10 Acceptable 0.1 0.0 0.0 0.0 0.1
05/09/2019 <10 Acceptable 0.0 0.0 0.0 0.1 0.1
10/11/2018 20 Acceptable 0.0 0.0 0.0 0.1 0.1
09/11/2018 52 Acceptable 0.0 1.7 0.1 0.1 1.9
08/15/2018 41 Acceptable 0.0 0.0 0.8 0.2 1.0
07/18/2018 1274 Beach Advisory 0.0 1.6 0.1 0.3 2.0
06/14/2018 10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/07/2018 75 Beach Advisory 0.0 0.2 0.0 0.0 0.2
10/17/2017 384 Beach Advisory 0.0 0.1 0.0 0.0 0.1
09/12/2017 10 Acceptable 0.0 0.0 0.0 0.0 0.0
08/15/2017 1793 Beach Advisory 0.1 0.0 0.0 0.4 0.5
07/11/2017 243 Beach Advisory 0.4 0.1 0.0 0.0 0.5
06/13/2017 52 Acceptable 0.0 0.0 0.0 0.0 0.0
05/16/2017 31 Acceptable 0.0 0.0 0.1 1.7 1.8
10/14/2016 31 Acceptable 0.0 0.1 0.0 0.0 0.1
09/15/2016 85 Beach Advisory 0.0 0.2 0.0 0.0 0.2
08/16/2016 <10 Acceptable 0.0 0.0 0.1 0.1 0.2
07/14/2016 30 Acceptable 0.2 0.0 0.0 0.0 0.2
06/16/2016 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/21/2016 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
10/13/2015 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
09/12/2015 <10 Acceptable 0.0 0.3 1.3 0.0 1.6
08/13/2015 <10 Acceptable 0.0 0.0 1.0 0.0 1.0
07/09/2015 10 Acceptable 0.3 0.3 0.1 0.0 0.7
06/11/2015 <10 Acceptable 0.0 0.0 0.2 0.2 0.4
05/12/2015 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
10/14/2014 <10 Acceptable 0.0 0.0 0.0 0.4 0.4
09/08/2014 20 Acceptable 0.0 0.0 0.0 0.0 0.0
08/12/2014 10 Acceptable 0.0 0.0 0.0 0.0 0.0
07/08/2014 41 Acceptable 0.2 0.0 0.0 0.0 0.2
06/13/2014 554 Beach Advisory 1.4 0.0 0.1 0.0 1.5
05/13/2014 31 Acceptable 0.0 0.0 0.1 0.3 0.4
10/17/2013 52 Acceptable 0.0 0.0 0.0 0.0 0.0
09/19/2013 10 Acceptable 0.0 0.0 0.0 0.0 0.0
08/15/2013 20 Acceptable 0.0 0.0 0.7 0.4 1.1
07/18/2013 31 Acceptable 0.0 0.0 0.0 0.0 0.0
06/20/2013 74 Beach Advisory 0.0 0.0 0.3 0.2 0.5
05/30/2013 <10 Acceptable 0.0 0.0 0.4 0.0 0.4
10/11/2012 52 Acceptable 0.0 0.1 0.0 0.0 0.1
09/11/2012 10 Acceptable 0.0 0.0 0.0 1.4 1.4
08/14/2012 41 Acceptable 0.0 0.0 0.0 0.0 0.0
07/17/2012 10 Acceptable 0.0 0.0 0.2 0.0 0.2
06/12/2012 63 Beach Advisory 0.5 0.0 0.0 0.0 0.5
05/16/2012 <10 Acceptable 0.1 0.4 0.1 0.0 0.6
10/20/2011 160 Beach Advisory 0.0 0.1 0.0 0.0 0.1
09/15/2011 4106 Beach Advisory 0.0 0.0 0.0 0.0 0.0
08/17/2011 <10 Acceptable 0.0 0.0 0.0 3.4 3.4
07/18/2011 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
06/28/2011 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/17/2011 2481 Beach Advisory 1.2 0.0 0.8 0.0 2.0
10/13/2010 <10 Acceptable 0.0 0.1 0.3 0.0 0.4
09/12/2010 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
08/18/2010 <10 Acceptable 0.0 0.0 0.2 0.3 0.5
07/22/2010 132 Beach Advisory 0.0 0.1 0.0 1.4 1.5
06/16/2010 10 Acceptable 0.0 0.0 0.0 0.0 0.0
05/22/2010 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
10/20/2009 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
09/15/2009 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
08/21/2009 10 Acceptable 0.0 0.0 0.0 0.0 0.0
07/29/2009 31 Acceptable 0.6 0.0 0.0 0.2 0.8
06/23/2009 <10 Acceptable 0.0 0.0 0.6 0.5 1.1
06/08/2009 <10 Acceptable 0.0 0.0 0.0 0.8 0.8
05/13/2009 6 Acceptable 0.0 0.0 0.0 0.0 0.0
10/21/2008 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
09/23/2008 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
08/21/2008 <10 Acceptable 0.0 0.0 0.0 0.0 0.0
07/15/2008 45 Acceptable 0.0 1.1 0.0 0.0 1.1
06/25/2008 337 Beach Advisory 0.0 0.0 0.0 0.1 0.1
06/16/2008 185 Beach Advisory 0.0 0.0 1.7 0.0 1.7
05/20/2008 41 Acceptable 0.0 0.0 0.2 0.1 0.3
09/09/2007 19 Acceptable 0.0 0.0 0.0 0.0 0.0
08/23/2007 19 Acceptable 0.0 0.0 1.3 0.1 1.4
07/16/2007 8 Acceptable 0.0 0.0 0.0 0.0 0.0
06/28/2007 10 Acceptable 0.0 0.7 0.0 0.0 0.7
06/20/2007 6 Acceptable 0.1 0.3 0.0 0.0 0.4
05/21/2007 11 Acceptable 0.0 0.0 0.2 0.0 0.2
04/25/2007 29 Acceptable 0.0 0.0 0.0 0.0 0.0
12/06/2006 50 Acceptable 0.0 0.0 0.0 0.0 0.0
10/20/2006 34 Acceptable 0.4 0.1 0.0 1.1 1.6
09/19/2006 28 Acceptable 0.0 0.0 0.0 0.0 0.0

Entero Count (fecal indicator) and Rainfall Correlation

108 Samples taken

All Water Quality Parameters

108 Samples taken

Sample Date [i] Entero 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 [i] Temp (f)
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Temperature

Hudson River water temperature changes seasonally. Surface water temperature can change on small scales in the river reflecting natural and human influences.

[i] Salinity
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Salinity

Estuaries like the Hudson are where freshwaters in rivers meet the sea. Salinity tells us about the relative contribution of fresh and salt water within a particular region of the estuary. 

[i] Chlorophyll
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Chlorophyll

A measure of the amount of microscopic algae present in the water. High chlorophyll counts can mean high levels of the nutrients phosphorus and nitrogen, and the threat, or presence, of algae blooms.

[i] Turbidity
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Turbidity

Turbidity is a measure of the amount of fine particles suspended in the water. As turbidity rises, light penetration, a key factor for aquatic plants and algae, diminishes.

[i] Oxygen
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Oxygen

Oxygen concentrations in the water are closely connected to biological activities. Surface waters are typically in equilibrium with the atmosphere such that the oxygen concentration near the surface is close to fully saturated (100%).

Sort Sort Sort Sort Sort Sort Sort Sort
10/17/2023 <10 Acceptable 16.42 2.12 1.23 9 102.3
09/19/2023 31 Acceptable 21.91 3.65 3.3 n/a n/a
08/22/2023 20 Acceptable 24.44 1.59 3.24 3.6 86.5
07/18/2023 10 Acceptable 26.5 0.15 3.33 7.4 82.6
06/27/2023 1130 Beach Advisory 72.0 5.2 5.0 10.5 81.6
05/02/2023 197 Beach Advisory 54.3 1.3 2.9 19.1 93.5
10/11/2022 20 Acceptable 62.3 7.9 2.5 7.2 83.5
09/11/2022 31 Acceptable 76.7 7.6 5.8 9.9 72.4
08/20/2022 63 Beach Advisory 79.6 7.2 11.9 10.8 99.4
07/16/2022 10 Acceptable 77.5 7.2 5 13.3 82.8
06/14/2022 20 Acceptable 71.1 4.6 18.4 21.9 104.5
05/24/2022 10 Acceptable 63.8 3.3 2 20.9 94.1
10/29/2021 717 Beach Advisory 58.1 0.4 4.6 9 87
09/14/2021 216 Beach Advisory 73.4 0.4 8.6 20 87
08/17/2021 933 Beach Advisory 78.0 3.7 8.9 16 83
07/20/2021 323 Beach Advisory 78.1 0.2 5.3 15 81
06/08/2021 10 Acceptable 70.3 3.5 18.1 12 109
05/18/2021 75 Beach Advisory 63.0 1.0 5.7 13 100
10/15/2020 408 Beach Advisory 64.9 8.4 2.9 8 88
09/19/2020 41 Acceptable 70.5 8.9 4.9 7 89
08/15/2020 313 Beach Advisory 83.4 4.9 17.3 14 130
07/15/2020 63 Beach Advisory 81.4 5.7 9.1 10 98
06/17/2020 <10 Acceptable 72.3 5.1 9.7 12 103
05/27/2020 <10 Acceptable 64.4 3.4 13.6 20 109
10/09/2019 30 Acceptable 67.1 5.5 3.8 8 83
09/11/2019 20 Acceptable 76.6 5.7 6.4 9 96
08/07/2019 97 Beach Advisory 82.7 5.4 12.4 11 91
07/10/2019 272 Beach Advisory 80.6 3.2 29.6 12 132
06/06/2019 <10 Acceptable 69.1 2.1 2.5 20 94
05/09/2019 <10 Acceptable 58.6 0.1 2.8 28 97
10/11/2018 20 Acceptable 71.3 0.1 4.6 20 89
09/11/2018 52 Acceptable 76.3 4.3 4.2 8 77
08/15/2018 41 Acceptable 82.7 0.6 5.3 21 88
07/18/2018 1274 Beach Advisory 80.9 5.4 16.6 20 118
06/14/2018 10 Acceptable 70.6 5.6 29.0 20 122
05/07/2018 75 Beach Advisory 56.2 0.1 2.2 29 102
10/17/2017 384 Beach Advisory 67.2 6.7 2.1 13 86
09/12/2017 10 Acceptable 73.8 5.8 4.4 15 85
08/15/2017 1793 Beach Advisory 80.2 3.8 8.8 13 91
07/11/2017 243 Beach Advisory 78.8 2.3 5.6 12 99
06/13/2017 52 Acceptable 73.3 0.2 6.8 14 120
05/16/2017 31 Acceptable 60.0 0.1 3.7 28 98
10/14/2016 31 Acceptable 64.6 8.9 3.1 36 91
09/15/2016 85 Beach Advisory 76.7 8.0 6.5 n/a 95
08/16/2016 <10 Acceptable 84.9 4.9 11.3 39 102
07/14/2016 30 Acceptable 79.5 5.1 15.8 12 100
06/16/2016 <10 Acceptable 72.3 3.4 13.4 21 107
05/21/2016 <10 Acceptable 60.6 1.8 5.2 68 98
10/13/2015 <10 Acceptable 67.4 6.1 6.4 22 92
09/12/2015 <10 Acceptable 79.4 6.9 4.0 24 82
08/13/2015 <10 Acceptable 79.6 5.8 27.9 20 110
07/09/2015 10 Acceptable 77.6 0.5 7.6 29 89
06/11/2015 <10 Acceptable 75.7 2.3 11.8 15 115
05/12/2015 <10 Acceptable 67.6 3.0 3.5 50 102
10/14/2014 <10 Acceptable 68.2 5.6 3.2 23 90
09/08/2014 20 Acceptable 78.4 4.0 11.3 28 101
08/12/2014 10 Acceptable 78.7 5.1 6.3 38 86
07/08/2014 41 Acceptable 81.3 1.1 5.8 26 100
06/13/2014 554 Beach Advisory n/a n/a n/a n/a n/a
05/13/2014 31 Acceptable 61.2 2.4 2.6 23 99
10/17/2013 52 Acceptable 68.4 6.3 3.1 11 88
09/19/2013 10 Acceptable 73.0 3.9 4.9 15 95
08/15/2013 20 Acceptable 79.3 2.2 5.2 28 97
07/18/2013 31 Acceptable 86.8 2.4 7.8 62 89
06/20/2013 74 Beach Advisory 72.2 0.1 2.6 17 99
05/30/2013 <10 Acceptable 70.1 0.3 1.9 22 93
10/11/2012 52 Acceptable 64.1 3.9 5.2 24 94
09/11/2012 10 Acceptable 75.5 5.1 5.1 104 94
08/14/2012 41 Acceptable 81.1 6.7 3.8 16 85
07/17/2012 10 Acceptable 84.2 7.3 13.6 6 113
06/12/2012 63 Beach Advisory 72.8 0.7 3.4 60 93
05/16/2012 <10 Acceptable 66.9 0.2 4.6 23 114
10/20/2011 160 Beach Advisory 63.6 0.1 1.4 208 91
09/15/2011 4106 Beach Advisory 70.0 0.1 1.8 121 83
08/17/2011 <10 Acceptable 83.8 3.7 4.6 31 103
07/18/2011 <10 Acceptable 83.4 1.2 5.8 17 n/a
06/28/2011 <10 Acceptable 79.6 1.5 7.2 54 98
05/17/2011 2481 Beach Advisory 62.2 0.3 n/a n/a 99
10/13/2010 <10 Acceptable 65.4 0.1 4.7 24 87
09/12/2010 <10 Acceptable 73.0 5.3 8.4 23 85
08/18/2010 <10 Acceptable 83.1 5.8 5.1 89 91
07/22/2010 132 Beach Advisory 83.7 6.2 20.9 42 151
06/16/2010 10 Acceptable 73.3 5.1 6.5 34 87
05/22/2010 <10 Acceptable 67.9 3.6 4.2 19 94
10/20/2009 <10 Acceptable 59.1 4.0 3.4 17 90
09/15/2009 <10 Acceptable 77.4 4.4 4.8 17 110
08/21/2009 10 Acceptable 83.4 2.8 7.9 12 96
07/29/2009 31 Acceptable 79.3 0.8 5.6 31 89
06/23/2009 <10 Acceptable 73.1 0.1 0.9 19 110
06/08/2009 <10 Acceptable n/a n/a n/a n/a n/a
05/13/2009 6 Acceptable 64.7 0.3 2.6 26 112
10/21/2008 <10 Acceptable 62.8 6.5 3.2 10 89
09/23/2008 <10 Acceptable 74.6 4.2 2.5 8 95
08/21/2008 <10 Acceptable 78.8 3.7 4.9 10 92
07/15/2008 45 Acceptable 82.1 4.5 4.3 18 116
06/25/2008 337 Beach Advisory 77.3 4.5 2.9 17 91
06/16/2008 185 Beach Advisory n/a n/a n/a n/a n/a
05/20/2008 41 Acceptable 59.1 2.1 1.5 41 97
09/09/2007 19 Acceptable 81.9 7.5 3.5 25 109
08/23/2007 19 Acceptable 75.3 5.7 2.8 16 88
07/16/2007 8 Acceptable 81.8 5.8 3.6 25 103
06/28/2007 10 Acceptable n/a n/a n/a n/a n/a
06/20/2007 6 Acceptable n/a n/a n/a n/a n/a
05/21/2007 11 Acceptable 63.5 0.2 1.6 60 96
04/25/2007 29 Acceptable 49.3 0.1 0.4 338 107
12/06/2006 50 Acceptable 44.6 0.1 1.1 13 96
10/20/2006 34 Acceptable n/a n/a n/a n/a n/a
09/19/2006 28 Acceptable n/a n/a n/a n/a n/a

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 Riverkeeper, Lamont-Doherty Earth Observatory and CUNY Queens College staff, 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:

Cortlandt, NY
The Hudson, off Furnace Brook, has recreational and subsistence fishing, as well as kayaking, and swimming from recreational boats.

Agencies Responsible:

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

Tell Gov. Hochul to block invasive species at the Erie and Champlain canals
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