September 9, 2014

 

 

E. COLI LEVELS CONTINUE TO FOLLOW PATTERN

 

The final test of the 2014 season showed the usual pattern for E. coli levels on the Merrimack and Souhegan Rivers. Both rivers showed little change over the course of the last month. The Merrimack remains very clean; the Souhegan less clean.

 

The highest E. coli count on the Merrimack showed up just above the Amoskeag Dam in Manchester. The count here was 82. The program looks for levels below 88 to signify clean water. Counts through Bedford, Litchfield, Merrimack, Hudson, and Nashua were in the 20-30 range, indicating a very clean river.

 

Low flow on the much smaller Souhegan River and the possible influence of heavy tornado rains in the headwaters on Saturday and an unexplained surge in flow Friday night produced much higher E. coli counts – especially in the more populated town centers. Counts rose above 88 passing through Greenville and peaked at 313 in downtown Wilton. Counts dropped through west Milford but peaked again near the Milford Oval to 248. The highest count on the river, 547.5, was measured in Amherst just downstream of the mouth of Beaver Brook. The monitor also noted a rotten egg odor coming from Beaver Brook. Downstream the counts dropped to more acceptable levels as the river passed through the more rural and slightly steeper Merrimack.

 

In spite of occasional blips above the acceptable E. coli levels, both rivers meet the Class B standards for swimmable and fishable rivers. It is usually only after heavy rainstorms that either of the rivers rises to dangerous swimming levels at most of the spots where people gather. With the exception of the Amherst Canoeport on Boston Post Road, all of the other normal swimming holes met acceptable levels this week also.

 

The Souhegan Watershed Association and Lower Merrimack River Local Advisory Committee have been monitoring these rivers for two decades and have seen major improvements. Plans are to continue to monitor again beginning in June next year. The program is always looking for volunteers to adopt a specific site or act as subs when needed. Anyone interested in more information can contact swawatertesting@gmail.com.

 

A map of the sites monitored on both rivers and the individual E. coli count for the season is available at www.nashuatelegraph.com/specialreportsrivertestresults/ and at souheganriver.org.

 

Professional lab technicians at the wastewater treatment plants in Manchester, Milford, Merrimack, and Nashua perform the tests for E. coli and Dissolved oxygen.

 

Here are this week’s numbers:

 

E-COLI MONITORING RESULTS FOR TESTS TAKEN ON SEPTEMBER 9, 2014

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 36.8,  #2  4.1

  2. SoR  333  Water Loom Pond, New Ipswich  7.5

  3. SoR  320  Highbridge, New Ipswich  88.2

  4. SoR  309  Above Greenville Mill Pond, Greenville  101.7

  5. SoR  296  Downtown Greenville upstream of WWTP  224.7

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

  7. SoR  218  Below the Horseshoe, Wilton   42.8

  8. SoR  210  Downtown Wilton  313.0

  9. SoR  201  Pine Valley Mill, West Milford   NA

  10. SoR  170  Behind Hayward Field, West Milford   NA

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  186.0

  12. SoR  146  Swing Bridge, Milford  248.1

  13. SoR  133  Riverside Cemetery, Milford   167.0  

  14. SoR  130  Behind Lorden Plaza, Milford  248.9

  15. SoR  122  Amherst Country Club  NA

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   547.5

  17. SoR  095  Boston Post Road Canoeport, Amherst  160.7

  18. Sor   070   Seaverns Bridge, Merrimack  90.9

  19. SoR  057  Indian Ledges, Merrimack  56.5

  20. SoR  034  Turkey Hill Bridge, Merrimack  NA   

  21. SoR  001   Watson Park, DW Hwy, Merrimack  24.9

 

 

MERRIMACK RIVER SITES:

 

1.      Mer  600  Above Amoskeag Dam, Manchester  82.0

2.      Mer  590  Arms Park, Manchester  52.0

3.      Mer  570  Goffs Falls, Litchfield  42.8

4.      Mer  560  Depot Street, Merrimack   32.7

5.      Mer  550  Upstream of Souhegan River, Merrimack   23.2

6.      Mer  540  Thorntons Ferry, Merrimack  25.9

7.      Mer  530  Greeley Park, Nashua  24.1

8.      Mer  520  Taylors Falls Bridge, Nashua   38.3

9.      Mer  510  Sagamore Bridge, Hudson  NA

10.  Mer  500  Pheasant Lane Mall, Hudson   NA

11.  Mer  490  Upstream of Tyngsboro Bridge  39.9

 

                                   

Flow on Upper Souhegan was 17 CFS and expected flow for that date is 19

Flow on Lower Souhegan was 52 CFS and historic flow for that date is 41

Flow on Merrimack was 2080 CFS and historic flow for that date is 1450

RAINFALL -  Sat afternoon, especially heavy in Souhegan headwaters. Otherwise clear.

Temperatures: Souhegan 16C;  Merrimack 20C



 There was sudden surge on Friday 9/5 that brought the upper Souhegan up from 20 to 200cfs from about 1pm to 3pm. This worked its way downstream to increase in Merrimack the next day from about 55 to 85 1am to 9am. No noticeable difference on the Merrimack.



 

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON SEPTEMBER 9, 2014

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 7.52,  #2  7.60

  2. SoR  333  River Road above Water Loom Pond, New Ipswich  7.41

  3. SoR  320  Highbridge, New Ipswich  8.53

  4. SoR  309  Above Greenville Mill Pond, Greenville  8.72

  5. SoR  296  Downtown Greenville upstream of WWTP  8.77

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP  8.92

  7. SoR  218  Below the Horseshoe, Wilton   9.75

  8. SoR  210  Downtown Wilton  9.86

  9. SoR  201  Pine Valley Mill, West Milford  NA

  10. SoR  170  Behind Hayward Field, West Milford   NA

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  7.86

  12. SoR  146  Swing Bridge, Milford  8.64

  13. SoR  133  Riverside Cemetery, Milford  8.51 

  14. SoR  130  Behind Lorden Plaza, Milford  8.21

  15. SoR  122  Amherst Country Club  NA

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst  7.71 

  17. SoR  095  Boston Post Road Canoeport, Amherst   7.45

  18. Sor   070   Seaverns Bridge, Merrimack  7.65

  19. SoR  057  Indian Ledges, Merrimack  8.73

  20. SoR  034  Turkey Hill Bridge, Merrimack   NA

  21. SoR  001   Watson Park, DW Hwy, Merrimack  9.37

 

 

MERRIMACK RIVER SITES:

 

12.  Mer  600  Above Amoskeag Dam, Manchester  8.09

13.  Mer  590  Arms Park, Manchester  8.71

14.  Mer  570  Goffs Falls, Litchfield  8.18

15.  Mer  560  Depot Street, Merrimack   8.26

16.  Mer  550  Upstream of Souhegan River, Merrimack   8.37

17.  Mer  540  Thorntons Ferry, Merrimack  8.27

18.  Mer  530  Greeley Park, Nashua  8.46

19.  Mer  520  Taylors Falls Bridge, Nashua   8.24

20.  Mer  510  Sagamore Bridge, Hudson  NA

21.  Mer  500  Pheasant Lane Mall, Hudson    NA

22.  Mer  490  Upstream of Tyngsboro Bridge  8.67