Potash Brook originates in South Burlington between Dorset and Spear Streets. The stream flows north, close to the Burlington International Airport and US Rte. 2. It then turns west where it flows and continues to flow through South Burlington before emptying into Lake Champlain in Shelburne Bay. Multiple smaller tributaries enter the main stem along its course.

The Potash Brook watershed covers 43% of the land area within South Burlington (Potash). Along its course it passes through several wetlands and natural areas (Stormwater, 1997). However, the land surrounding the stream’s main stem is generally highly developed. The Potash Brook watershed is home to some of the densest residential and commercial development within Vermont (East Woods). The 7.5 square mile watershed is over 19% impervious. 

South Burlington has a population of around 16,000 people and is one of the largest municipalities in Vermont. The Champlain Water District (CWD), which provides drinking water to South Burlington and other municipalities in the area, draws its water from Shelburne Bay. Potash Brook has a history of high bacteria levels, which is a concern for the CWD and area residents (Potash, 2003). 

 

Currently, the Stream Team is monitoring three sites along Potash Brook with the help of volunteers.  Water samples are being taken twice a month throughout the summer and are tested for phosphorus, turbidity, chloride and nitrogen. 

Location Date Chloride (mg/L) Nitrogen, Total – Persulfate (mg/L) Phosphorus – Total (TP) (µg/L) Turbidity (NTU)
Potash 10 9/1/2015 424 -- 23.5 2.7
Potash 20 9/1/2015 402.5 -- 26.6 1.33
Potash 30 9/1/2015 293.4 -- 55.9 9.27
Potash 10 8/18/15 361 -- 29.1 2.55
Potash 20 8/18/15 369.8 -- 41.4 1.3
Potash 30 8/18/15 295.8 -- 67.4 6.68
Potash 10 8/4/2015 419.25 -- 25 2.71
Potash 20 8/4/2015 422.25 -- 26.6 1.33
Potash 30 8/4/2015 313.2 -- 50.9 7.14
Potash 10 7/21/2015 315.8 -- 45 2.67
Potash 20 7/21/2015 299.4 -- 28.4 1.73
Potash 30 7/21/2015 263.4 -- 56 7.48
Potash 10 7/7/2015 234.4 -- 51 6.29
Potash 20 7/7/2015 252.8 -- 32.5 3.07
Potash 30 7/7/2015 261.8 -- 32.6 3.75
Potash 10 6/23/2015 185 -- 83.1 15.8
Potash 20 6/23/2015 205.7 -- 58.3 10.6
Potash 30 6/23/2015 161.8 -- 56.8 6.83
Potash 20 10/21/2014 266 -- 31.7 1.81
Potash 10 8/19/2014 324 -- 29 2.44
Potash 20 8/19/2014 298 -- 30.4 1.4
Potash 30 8/19/2014 340 -- 34.6 3.41
Potash 10 8/5/2014 346 -- 24.1 2.74
Potash 20 8/5/2014 342 -- 26.3 1.61
Potash 30 8/5/2014 294 -- 55.1 5.34
Potash 10 7/22/2014 384 -- 22.3 2.1
Potash 20 7/22/2014 368 -- 23.3 1.26
Potash 30 7/22/2014 338 -- 50.6 5.56
Potash 10 7/8/2014 406 -- 29.9 2.82
Potash 20 7/8/2014 424 -- 31.9 2.91
Potash 30 7/8/2014 324 -- 45.9 4.99
Potash 10 6/24/2014 440 -- 29.7 2.95
Potash 20 6/24/2014 444 -- 30.8 1.6
Potash 30 6/24/2014 354 -- 36.1 3.58
Potash 20 10/06/13 270.00  0.57 31.90  3.18
Potash 20 9/10/13 210.00 0.66 51.50  3.76
Potash 10 8/27/2013 199 0.84 66.5 8.72
Potash 20 8/27/13 182.00 0.74 55.60  6.46
Potash 30 8/27/13 199.00 0.64 48.40  4.36
Potash 10 8/13/13 346.00  0.86 34.10  2.01
Potash 20 8/13/13 298.00  0.76 34.10  1.27
Potash 30 8/13/13 240.00 0.75 43.90  2.96
Potash 10 7/23/13 276.00 0.81 42.6 5.16
Potash 20 7/23/13 360.00  0.89 41.70  3.01
Potash 30 7/23/2013 222.00 0.69 61.10  4.86
Potash 10 7/09/13 160 0.88 60.30  4.24
Potash 20 7/09/13 159.00 0.87 60.50  3.95
Potash 30 7/09/13 161.00 0.79 63.00  5.32
Potash 10 6/25/13 164.00 0.63 47.80  3.41
Potash 20 6/25/13 149.00 0.61 48.7 3.73
Potash 30 6/25/13 186.00 0.56 49.3 3.44
Potash 10 9/11/2012 232 0.55 36.7 3.16
Potash 20 9/11/2012 232 0.53 39.9 2.92
Potash 30 9/11/2012 234 0.6 46.9 3.8
Potash 10 8/21/2012 328 0.53 24.8 2.68
Potash 20 8/21/2012 427 0.47 28 1.05
Potash 30 8/21/2012 289 0.83 51.7 5.54
Potash 10 8/7/2012 355 0.71 30.8 2.5
Potash 20 8/7/2012 366 0.53 60.5 1.03
Potash 30 8/7/2012 268 0.61 34.7 4.06
Potash 10 7/24/2012 120 0.76 109 21.1
Potash 20 7/24/2012 152 0.7 112 18.5
Potash 30 7/24/2012 113 0.66 106 7.8
Potash 10 7/10/2012 332 0.77 30.3 2.92
Potash 20 7/10/2012 335 0.67 34.9 2.04
Potash 30 7/10/2012 321 0.84 59.3 8.33
Average 2012 273.60 0.65 53.70 5.83
Average 2013 179.50 0.72 51.78 6.23
Average 2014 355.75 --  33.23 2.91
Average 2015 296.98 --  43.48 5.51

The Stream Team has also been monitoring Potash Brook during storm events.  The results below indicate water quality during two rain storms.

Location Date Chloride (mg/L) Nitrogen, Total persulfate (mg/L) Phosphorus Digested (ug P/L) TSS (mg/L) Turbidity (NTU)
Potash 20 8/18/2015 424.4  -- 34.6  -- 2.52
Potash 20 8/28/2012 353 0.64 43.4 1.4  
Potash 20 8/12/2012 106 0.63 97.9 19.2  --