JUNE 16

 

RAIN WASHES E. COLI INTO RIVERS AGAIN

 

Rain on Monday after two weeks of dry weather washed E. coli bacteria into local rivers according to tests performed on the Merrimack and Souhegan Rivers on Tuesday morning. However, there has been no rain since then, so it is expected that the E. coli levels have dropped to more acceptable levels – probably OK for swimming now according to the testing program.

 

The eleven sites tested on the Merrimack between Manchester and Tyngsborough had good results with one exception: the boat access at Greeley Park spiked up to 727. Results higher than 88 are not acceptable for swimming according to the test. The rest of the Merrimack tested well below the 88 limit. The next highest number was at Depot Street in Merrimack at only 56.9.

 

The Souhegan River, as a smaller river, is more affected by rainfall. The upper stretch of the river, from New Ipswich to Wilton, tested at reasonable levels, less than 88; the lower section, from Wilton to Merrimack, jumped to a 400 level, approaching a dangerous level in some spots for swimming. Some of the usual swimming spots like the Boston Post Road Canoeport in Amherst, Indian Ledges and Turkey Hill Bridge in Merrimack were slightly higher than acceptable, in the 110-150 range. Watson Park in Merrimack, however, tested at an acceptable 49.6.

 

The testing program also tests for dissolved oxygen levels in both rivers. This gives a better indication of the actual health of the river. At this time of year, the DO levels are expected to be good. The tests found they are actually excellent, some of the best levels ever seen in the Souhegan. The dams on the Merrimack reduce the DO levels, but the tests showed still very good results.

 

An even better indicator of the health of the river is an inventory of the various insects that live in the river. Recent surveys of the Souhegan River in Milford found many bugs that can survive only in pollution-free water. The chemical analysis is important but macroinvertibrate analysis is the gold standard for determining the health of the river.

 

The Souhegan River is monitored in its entire length which stretches from Ashburnham, MA, to Merrimack, NH, over 35 miles. Typically the Souhegan has low E. coli levels and excellent dissolved oxygen levels in the upper half of the river – to West Milford. From here to the mouth of the river in Merrimack, the river meanders back and forth over sandy soil, slows down, and the E. coli levels increase – usually only to still acceptable levels. Dissolved oxygen levels also drop but still to very acceptable levels.

 

Several of the sites that should be monitored were not monitored this week for lack of volunteers. SWA welcomes anyone interested in helping out by adopting a site and collecting data once every two weeks. Potential volunteers can contact swawatertesting@gmail.com or  georgemay@comcast.net for more information.

 

More information can be found at www.souheganriver.org.

 

The next test will be done on June 30.

 

The lab tests are all done by certified personnel at the wastewater treatment plants in Manchester, Milford,  Nashua, and Merrimack. The program is coordinated by the Souhegan Watershed Association.

 

E-COLI MONITORING RESULTS FOR TESTS TAKEN ON JUNE 16, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 15.8,  #2  7.5

  2. SoR  333  Water Loom Pond, New Ipswich  10.1

  3. SoR  320  Highbridge, New Ipswich  67.7

  4. SoR  309  Above Greenville Mill Pond, Greenville  86.0

  5. SoR  296  Downtown Greenville upstream of WWTP  NA

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

  7. SoR  218  Below the Horseshoe, Wilton   NA

  8. SoR  210  Downtown Wilton  NA

  9. SoR  201  Pine Valley Mill, West Milford   275.5

  10. SoR  170  Behind Hayward Field, West Milford   NA

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

  12. SoR  146  Swing Bridge, Milford  410.6

  13. SoR  133  Riverside Cemetery, Milford    461.1

  14. SoR  130  Behind Lorden Plaza, Milford  461.1  (DUP 387.3)

  15. SoR  122  Amherst Country Club  365.4

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

  17. SoR  095  Boston Post Road Canoeport, Amherst  162.4

  18. SoR   070   Seaverns Bridge, Merrimack  121.1

  19. SoR  057  Indian Ledges, Merrimack  NA

  20. SoR  034  Turkey Hill Bridge, Merrimack     113.7

  21. SoR  001   Watson Park, DW Hwy, Merrimack  49.6 (DUP 60.2)

 

 

MERRIMACK RIVER SITES:

 

1.      Mer  600  Above Amoskeag Dam, Manchester  31.8

2.      Mer  590  Arms Park, Manchester  42.2

3.      Mer  570  Goffs Falls, Litchfield  48.7

4.      Mer  560  Depot Street, Merrimack    56.9

5.      Mer  550  Upstream of Souhegan River, Merrimack   NA

6.      Mer  540  Thorntons Ferry, Merrimack  NA

7.      Mer  530  Greeley Park, Nashua  727.0

8.      Mer  520  Taylors Falls Bridge, Nashua   NA

9.      Mer  510  Sagamore Bridge, Hudson  34.5

10.  Mer  500  Pheasant Lane Mall, Hudson    NA

11.  Mer  490  Upstream of Tyngsboro Bridge  38.8

 

Flow on Upper Souhegan was 103 cubic feet per second; expected flow for that date is 84 cfs.

Flow on Lower Souhegan was 108 cubic feet per second; historic flow for that date is 151 cfs.

Flow on Merrimack was 2600 cubic feet per second; historic flow for that date is 3890 cfs.

RAINFALL – Sat - Sun clear. Rain Mon .3”.

Water temperatures: Souhegan 18C; Merrimack 21C

 

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON JUNE 16, 2015

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 7.71,   #2 8.03

  2. SoR  333  River Road above Water Loom Pond, New Ipswich  11.6

  3. SoR  320  Highbridge, New Ipswich  12.0

  4. SoR  309  Above Greenville Mill Pond, Greenville  12.6

  5. SoR  296  Downtown Greenville upstream of WWTP  NA

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

  7. SoR  218  Below the Horseshoe, Wilton   NA

  8. SoR  210  Downtown Wilton  NA

  9. SoR  201  Pine Valley Mill, West Milford   9.5

  10. SoR  170  Behind Hayward Field, West Milford   9.15

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

  12. SoR  146  Swing Bridge, Milford  8.59

  13. SoR  133  Riverside Cemetery, Milford   9.12

  14. SoR  130  Behind Lorden Plaza, Milford  9.0 (DUP 9.15)

  15. SoR  122  Amherst Country Club  9.04

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   8.85

  17. SoR  095  Boston Post Road Canoeport, Amherst  7.89

  18. Sor   070   Seaverns Bridge, Merrimack  7.64

  19. SoR  057  Indian Ledges, Merrimack  NA

  20. SoR  034  Turkey Hill Bridge, Merrimack    10.5

  21. SoR  001   Watson Park, DW Hwy, Merrimack  8.9

 

 

MERRIMACK RIVER SITES:

 

12.  Mer  600  Above Amoskeag Dam, Manchester  8.13

13.  Mer  590  Arms Park, Manchester  8.71

14.  Mer  570  Goffs Falls, Litchfield  8.36

15.  Mer  560  Depot Street, Merrimack   9.4

16.  Mer  550  Upstream of Souhegan River, Merrimack   NA

17.  Mer  540  Thorntons Ferry, Merrimack  NA

18.  Mer  530  Greeley Park, Nashua  7.98

19.  Mer  520  Taylors Falls Bridge, Nashua   NA

20.  Mer  510  Sagamore Bridge, Hudson  8.04

21.  Mer  500  Pheasant Lane Mall, Hudson    NA

22.  Mer  490  Upstream of Tyngsboro Bridge  8.08

 

                                   

Flow on Upper Souhegan was 103 cubic feet per second; expected flow for that date is 84 cfs. (PEAKED – PROBABLY RELEASE FROM DAM)

Flow on Lower Souhegan was 108 cubic feet per second; historic flow for that date is 151 cfs.

Flow on Merrimack was 2600 cubic feet per second; historic flow for that date is 3890 cfs.

RAINFALL – Sat - Sun clear. Rain Mon .3”.

Water temperatures: Souhegan 18C; Merrimack 21C