JULY 14th

 

RIVERS BACK TO NORMAL

 

E. coli levels in both the Merrimack and Souhegan Rivers returned to a more acceptable, normal level this week according to tests done by the Souhegan Watershed Association as part of their regular ongoing water quality testing program.

 

Since the beginning of June Tuesday morning tests were conducted after heavy rainstorms. Heavy rainstorms are responsible for increasing the bacteria levels in the rivers. And both rivers had generally unacceptable levels of E. coli during that time. This week no rain preceeded the tests and the E. coli levels came down.

 

The Merrimack River between Manchester and Tyngsborough normally tests as very clean for bacteria levels – and this week, without rain, it returned to normal. The average bacteria level for the river monitored at eleven sites came out to 26. Numbers less than 88 are considered healthy for swimming in NH rivers. None of the eleven sites tested had a count higher than that. Goffs Falls, a popular eddy, was 45.

 

The Souhegan River is a much smaller river and therefore more responsive to rain events that wash bacteria into the river from natural riverbanks and from storm drains and parking lots directed to the river. After heavy rains the Souhegan generally shows unhealthy increases in the bacteria levels. This week the average count in the upper, faster moving stretch, from New Ipswich to Wilton was a healthy 25. From Milford to Merrimack the river meanders back and forth, slows down, warms up, and bacteria counts generally increase. This week the average count in this section was an unhealthy 190.

 

Although there are no public beaches on the Souhegan, swimmers congregate at a number of ‘swimming holes’ that are tested. Water Loom Pond in New Ipswich , the Boston Post Road Canoeport in Amherst, Indian Ledges, Turkey Hill Bridge, and Watson Park in Merrimack all tested at acceptable levels. The Horseshoe in Wilton tested at 124, not perfect but generally OK for healthy adults . The actual results for each particular site are available at www.souheganriver.org.

 

The flow on both rivers is still slightly higher than its expected, historical average, but all of the 30 monitors taking samples Tuesday morning noted how much lower the water was from the prior test dates after the heavy rains.

 

Monitors noted the abundance of flowering plants and animal tracks along the riverbanks, but also noted the abundance of mosquitoes. Monitors also pick up trash left by careless kids and fishermen at some of the sites. The boat access at Thorntons Ferry in Merrimack is a popular ATV area and particular offender.

 

Besides the 30 monitors that have adopted their sites and deliver their samples and data, certified lab personnel in the Greenville, Milford, Merrimack, Manchester, and Nashua waste treatment facilities perform the tests for dissolved oxygen and E. coli bacteria.

 

Tests are collected every two weeks during the summer. The next test will be done on July 28; results will be available the following day.

 

Here are this week’s results:

 

E-COLI MONITORING RESULTS FOR TESTS TAKEN ON JULY 14, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1  3.1, #2  <1.0

  2. SoR  333  Water Loom Pond, New Ipswich  5.2

  3. SoR  320  Highbridge, New Ipswich  14.6

  4. SoR  309  Above Greenville Mill Pond, Greenville  43.2

  5. SoR  296  Downtown Greenville upstream of WWTP  18.3

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP   33.6

  7. SoR  218  Below the Horseshoe, Wilton   123.6

  8. SoR  210  Downtown Wilton   387.3

  9. SoR  201  Pine Valley Mill, West Milford   156.5

  10. SoR  170  Behind Hayward Field, West Milford   NA 

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  172.3

  12. SoR  146  Swing Bridge, Milford   228.2

  13. SoR  133  Riverside Cemetery, Milford   150.0 

  14. SoR  130  Behind Lorden Plaza, Milford   133.3 (DUP 88.2)

  15. SoR  122  Amherst Country Club  198.9

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

  17. SoR  095  Boston Post Road Canoeport, Amherst  83.6

  18. SoR   070   Seaverns Bridge, Merrimack  86.0

  19. SoR  057  Indian Ledges, Merrimack  59.1

  20. SoR  034  Turkey Hill Bridge, Merrimack    NA

  21. SoR  001   Watson Park, DW Hwy, Merrimack  38.9

 

  1. Beaver Brook, Amherst  160.7

 

 

MERRIMACK RIVER SITES:

 

1.      Mer  600  Above Amoskeag Dam, Manchester  28.2

2.      Mer  590  Arms Park, Manchester  8.4

3.      Mer  570  Goffs Falls, Litchfield  44.8

4.      Mer  560  Depot Street, Merrimack    33.1

5.      Mer  550  Upstream of Souhegan River, Merrimack   NA

6.      Mer  540  Thorntons Ferry, Merrimack  27.9

7.      Mer  530  Greeley Park, Nashua  34.5

8.      Mer  520  Taylors Falls Bridge, Nashua   21.1

9.      Mer  510  Sagamore Bridge, Hudson  26.5

10.  Mer  500  Pheasant Lane Mall, Hudson   NA

11.  Mer  490  Upstream of Tyngsboro Bridge  10.9

 

                                   

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON JULY 14, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1  7.57, #2  7.63

  2. SoR  333  Water Loom Pond, New Ipswich  7.61

  3. SoR  320  Highbridge, New Ipswich   8.02

  4. SoR  309  Above Greenville Mill Pond, Greenville  7.93

  5. SoR  296  Downtown Greenville upstream of WWTP  8.31

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP   8.47

  7. SoR  218  Below the Horseshoe, Wilton   9.17

  8. SoR  210  Downtown Wilton  8.99

  9. SoR  201  Pine Valley Mill, West Milford   8.54  

  10. SoR  170  Behind Hayward Field, West Milford   NA

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  7.19

  12. SoR  146  Swing Bridge, Milford  7.48

  13. SoR  133  Riverside Cemetery, Milford   7.84

  14. SoR  130  Behind Lorden Plaza, Milford  7.73 (DUP  8.07)

  15. SoR  122  Amherst Country Club  7.71

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

  17. SoR  095  Boston Post Road Canoeport, Amherst  7.0

  18. Sor   070   Seaverns Bridge, Merrimack  7.12

  19. SoR  057  Indian Ledges, Merrimack   8.05

  20. SoR  034  Turkey Hill Bridge, Merrimack   7.44

  21. SoR  001   Watson Park, DW Hwy, Merrimack   8.46

 

  1. Beaver Brook, Amherst  5.83

 

 

MERRIMACK RIVER SITES:

 

  1. Mer  600  Above Amoskeag Dam, Manchester  7.85

  2. Mer  590  Arms Park, Manchester  8.17

  3. Mer  570  Goffs Falls, Litchfield  7.85

  4. Mer  560  Depot Street, Merrimack    7.90

  5. Mer  550  Upstream of Souhegan River, Merrimack   NA

  6. Mer  540  Thorntons Ferry, Merrimack  7.99

  7. Mer  530  Greeley Park, Nashua  8.27

  8. Mer  520  Taylors Falls Bridge, Nashua    8.49

  9. Mer  510  Sagamore Bridge, Hudson  8.37

  10. Mer  500  Pheasant Lane Mall, Hudson    NA

  11. Mer  490  Upstream of Tyngsboro Bridge  8.63

 

 

Flow on Upper Souhegan was 51 CFS and expected flow for that date is 26

Flow on Lower Souhegan was 112 CFS and historic flow for that date is 62

Flow on Merrimack was 2020 CFS and historic flow for that date is 1970 (very fluctuating flows)

RAINFALL -  Clear

Temperatures: Souhegan 22C;  Merrimack 25C