AUGUST 11th

 

 

DOWNTOWNS HAVE HIGH E. COLI

 

Testing for E. coli bacteria on the Souhegan and Merrimack Rivers showed significant differences between the two rivers. The Merrimack was the clear winner. Bacteria levels between Manchester and Tyngsborough were in the teens, well below the 88 level required for public swimming areas in NH.

 

The Souhegan tested clean in the upstream reaches and the downstream reaches, but the middle of the river showed dangerously high counts. The river tested clean until it reached the downtown at Wilton. Here the river tested at close to 1000, very high, very dangerous. Dilution of the pollution took place through West Milford, though counts remained still too high for human use; but counts spiked up again once the river reached the Oval area. The count near the Swing Bridge was near 550.

 

Below Milford, through Amherst, dilution again reduced the counts and generally reached acceptable levels by the time it reached Merrimack. The count at Watson Park in Merrimack, near the mouth of the river, was 36, quite clean.

 

Most of the swimming holes along the Souhegan were OK for swimming and other human use. The Amherst Canoeport on Boston Post Road was a bit high at 121, but still OK for healthy adults. The Horseshoe in Wilton was not tested this week.

 

Once again the Merrimack River tested very clean for bacteria and dissolved oxygen as it has for the last several years as the river has cleaned up. Dissolved oxygen is a positive test for the actual health of the river itself; both rivers constantly test very good in this test.

 

There was a drizzle during the Tuesday morning tests but not enough to account for any substantial changes in either of the tests. Heavy rains, especially after a dry spell, cause the bacteria level to rise, sometimes substantially, as water from the riverbanks and storm drains flush into the rivers.

 

These tests are performed by volunteers with the Souhegan Watershed Association biweekly during the summer. Results are always available on the internet at www.souheganriver.org. Results from past years are also there.

 

The lab tests are done by certified personnel at the wastewater treatment plants in Nashua,  Merrimack, Milford, and Manchester.

 

The next collection date is August 25; the bacteria take 24 hours to grow before the results can be read; the information should be available the following day.

 

SWA is always looking for volunteers; about 30 are needed. If anyone is interested in helping out for next year, contact swawatertesting@gmail.com.

 

Here are this week’s results. The lower the number the better:

 

E-COLI MONITORING RESULTS FOR TESTS TAKEN ON AUGUST 11, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1  32.7,  #2  4.1

  2. SoR  333  Water Loom Pond, New Ipswich  2.0

  3. SoR  320  Highbridge, New Ipswich  78.9

  4. SoR  309  Above Greenville Mill Pond, Greenville 67.0

  5. SoR  296  Downtown Greenville upstream of WWTP  36.9

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP   37.4

  7. SoR  218  Below the Horseshoe, Wilton  NA

  8. SoR  210  Downtown Wilton  980.4

  9. SoR  201  Pine Valley Mill, West Milford  461.1

  10. SoR  170  Behind Hayward Field, West Milford  NA  

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  488.4

  12. SoR  146  Swing Bridge, Milford  547.5

  13. SoR  133  Riverside Cemetery, Milford   196.8  

  14. SoR  130  Behind Lorden Plaza, Milford   114.5

  15. SoR  122  Amherst Country Club  79.4

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   NA

  17. SoR  095  Boston Post Road Canoeport, Amherst  121.1

  18. SoR   070   Seaverns Bridge, Merrimack  67.7

  19. SoR  057  Indian Ledges, Merrimack  33.1

  20. SoR  034  Turkey Hill Bridge, Merrimack   43.5   

  21. SoR  001   Watson Park, DW Hwy, Merrimack  36.4

 

 

MERRIMACK RIVER SITES:

 

1.      Mer  600  Above Amoskeag Dam, Manchester  6.3

2.      Mer  590  Arms Park, Manchester  24.6

3.      Mer  570  Goffs Falls, Litchfield  22.6

4.      Mer  560  Depot Street, Merrimack   NA

5.      Mer  550  Upstream of Souhegan River, Merrimack   16.9

6.      Mer  540  Thorntons Ferry, Merrimack  15.6

7.      Mer  530  Greeley Park, Nashua  9.8

8.      Mer  520  Taylors Falls Bridge, Nashua   13.2

9.      Mer  510  Sagamore Bridge, Hudson  13.4

10.  Mer  500  Pheasant Lane Mall, Hudson   NA

11.  Mer  490  Upstream of Tyngsboro Bridge  8.6

 

                                   

Flow on Upper Souhegan was 21 CFS and expected flow for that date is 46

Flow on Lower Souhegan was 38 CFS and historic flow for that date is 43

Flow on Merrimack was 1180 CFS and historic flow for that date is 1750

RAINFALL -  Clear

Temperatures: Souhegan 21C;  Merrimack 23C

 

 

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON AUGUST 11, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1  7.28,  #2  7.34

  2. SoR  333  River Road above Water Loom Pond, New Ipswich  7.66

  3. SoR  320  Highbridge, New Ipswich  8.09

  4. SoR  309  Above Greenville Mill Pond, Greenville  7.48

  5. SoR  296  Downtown Greenville upstream of WWTP  8.23

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP   8.23

  7. SoR  218  Below the Horseshoe, Wilton   NA

  8. SoR  210  Downtown Wilton  8.81

  9. SoR  201  Pine Valley Mill, West Milford   8.37

  10. SoR  170  Behind Hayward Field, West Milford   NA

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  7.24

  12. SoR  146  Swing Bridge, Milford  8.38

  13. SoR  133  Riverside Cemetery, Milford   7.56

  14. SoR  130  Behind Lorden Plaza, Milford  7.42

  15. SoR  122  Amherst Country Club  7.55

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   NA

  17. SoR  095  Boston Post Road Canoeport, Amherst  7.15

  18. Sor   070   Seaverns Bridge, Merrimack  7.35

  19. SoR  057  Indian Ledges, Merrimack  8.30

  20. SoR  034  Turkey Hill Bridge, Merrimack   7.05

  21. SoR  001   Watson Park, DW Hwy, Merrimack  8.73

 

 

MERRIMACK RIVER SITES:

 

12.  Mer  600  Above Amoskeag Dam, Manchester  8.33

13.  Mer  590  Arms Park, Manchester  8.21

14.  Mer  570  Goffs Falls, Litchfield  7.89

15.  Mer  560  Depot Street, Merrimack   NA

16.  Mer  550  Upstream of Souhegan River, Merrimack   8.07

17.  Mer  540  Thorntons Ferry, Merrimack  8.01

18.  Mer  530  Greeley Park, Nashua  8.45

19.  Mer  520  Taylors Falls Bridge, Nashua   8.72

20.  Mer  510  Sagamore Bridge, Hudson  8.57

21.  Mer  500  Pheasant Lane Mall, Hudson   NA

22.  Mer  490  Upstream of Tyngsboro Bridge  8.95