JULY 29, 2014

 

HEAVY RAINS RAISE E.COLI LEVELS

 

Heavy rains on Sunday and Monday raised both the dissolved oxygen and E. coli levels on the Souhegan and Merrimack Rivers this week. One is good; one is bad. The E. coli is bad. Levels all along the Souhegan tested at unacceptable levels for swimming; the levels on the Merrimack between Manchester and Tyngsborough were better but still too high to be acceptable. Levels higher than 88 are unsatisfactory for public swimming areas in NH; levels between 88 and 126 are satisfactory for most people at ‘swimming holes’; levels higher than 126 should be avoided.

 

Almost all the sites tested along the Souhegan had levels above 126, but the levels were not as high as expected after the heavy rains. And if the weather cooperates and doesn’t rain for a few days, the levels should return to more acceptable levels according to George May, the water monitoring coordinator. The next test will not be until August 12. The highest E. coli level on the Souhegan showed up at Watson Park, a popular swimming spot in Merrimack. The level here was a very unacceptable 435. This site alone will be retested again next Tuesday and the results will be available at www.souheganriver.org on Wednesday.

 

E. coli results for the Merrimack River came in all over the place. There was a very acceptable number in the pond above the Amoskeag Bridge in Manchester and again at the Tyngsborough Bridge. But in between Manchester and Tyngsborough all of the test sites were unacceptable. The Greeley Park boat ramp in Nashua tested at 613, just upstream of the mouth of the Nashua River. The Taylors Falls Bridge site, just downstream of the Nashua River, soared to 1046. However, by the time the river reached Tyngsborough, the E. coli number was back down to an acceptable 44.

 

Flows on both rivers have been higher than their historic averages all summer. The Merrimack River saw a huge increase in its flow rate this week. Historically the river flow should be around 1770 cubic feet per second at the time of the test on Tuesday; the actual flow rate was 7180 cfs. The huge flow is probably responsible for the disparity in the E. coli numbers.

 

The rainstorms also increased the dissolved oxygen counts in both rivers. Higher oxygen levels are better for the plants, animals, and fish in the rivers and are generally a better indication of the overall health of a river. Oxygen levels tested excellent this week.

 

All of the samples are collected by 30 volunteers with the Souhegan Watershed Association and the Lower Merrimack River Local Advisory Committee. The lab tests are all done by certified personnel at the wastewater treatment plants in Manchester, Milford,  Nashua, and Merrimack.

 

All of the results can be found at nashuatelegraph.com/specialreportsrivertestresults/ or souheganriver.org.

 

The next test will be done on August 12. Results are available the following day.

 

Here are the E. coli results for this week. Numbers lower than 88 are excellent; under 126 are acceptable for most healthy people.

 

E-COLI MONITORING RESULTS FOR TESTS TAKEN ON JULY 29, 2014

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 NA, #2 NA

  2. SoR  333  Water Loom Pond, New Ipswich  21.6

  3. SoR  320  Highbridge, New Ipswich  146.7

  4. SoR  309  Above Greenville Mill Pond, Greenville  185.0

  5. SoR  296  Downtown Greenville upstream of WWTP  129.6

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP  155.3

  7. SoR  218  Below the Horseshoe, Wilton   NA

  8. SoR  210  Downtown Wilton  165.8

  9. SoR  201  Pine Valley Mill, West Milford   517.2

  10. SoR  170  Behind Hayward Field, West Milford  178.5 

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  261.3

  12. SoR  146  Swing Bridge, Milford  275.5

  13. SoR  133  Riverside Cemetery, Milford  248.1  

  14. SoR  130  Behind Lorden Plaza, Milford  186.0

  15. SoR  122  Amherst Country Club  201.4

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   109.5

  17. SoR  095  Boston Post Road Canoeport, Amherst  187.2

  18. Sor   070   Seaverns Bridge, Merrimack  107.6

  19. SoR  057  Indian Ledges, Merrimack  74.9

  20. SoR  034  Turkey Hill Bridge, Merrimack  NA   

  21. SoR  001   Watson Park, DW Hwy, Merrimack  435.2

 

 

MERRIMACK RIVER SITES:

 

1.      Mer  600  Above Amoskeag Dam, Manchester  45.0

2.      Mer  590  Arms Park, Manchester  93.4

3.      Mer  570  Goffs Falls, Litchfield  110.6

4.      Mer  560  Depot Street, Merrimack    260.3

5.      Mer  550  Upstream of Souhegan River, Merrimack   185.0

6.      Mer  540  Thorntons Ferry, Merrimack  365.4

7.      Mer  530  Greeley Park, Nashua  613.1

8.      Mer  520  Taylors Falls Bridge, Nashua   1046.2

9.      Mer  510  Sagamore Bridge, Hudson  435.2

10.  Mer  500  Pheasant Lane Mall, Hudson   NA

11.  Mer  490  Upstream of Tyngsboro Bridge  44.3

 

                       

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON JULY 29, 2014

 

SOUHEGAN RIVER SITES:

 

  1. Billy Ward Pond, Ashburnham  #1 NA, #2 NA

  2. SoR  333  River Road above Water Loom Pond, New Ipswich  6.90

  3. SoR  320  Highbridge, New Ipswich  8.17

  4. SoR  309  Above Greenville Mill Pond, Greenville  8.17

  5. SoR  296  Downtown Greenville upstream of WWTP  8.37

  6. SoR  291  Green Bridge off Rte 31 below Greenville WWTP  8.36

  7. SoR  218  Below the Horseshoe, Wilton   NA

  8. SoR  210  Downtown Wilton  9.13

  9. SoR  201  Pine Valley Mill, West Milford   8.74

  10. SoR  170  Behind Hayward Field, West Milford   8.09

  11. SoR  155  Souhegan Valley Boys and Girls Club, Milford  7.78

  12. SoR  146  Swing Bridge, Milford  8.04

  13. SoR  133  Riverside Cemetery, Milford   8.31

  14. SoR  130  Behind Lorden Plaza, Milford  8.17

  15. SoR  122  Amherst Country Club  8.23

  16. SoR  116  Amherst Conservation land Fairway Road, Amherst   7.87

  17. SoR  095  Boston Post Road Canoeport, Amherst  7.73

  18. Sor   070   Seaverns Bridge, Merrimack  7.42

  19. SoR  057  Indian Ledges, Merrimack  8.14

  20. SoR  034  Turkey Hill Bridge, Merrimack  NA   

  21. SoR  001   Watson Park, DW Hwy, Merrimack  8.83

 

 

MERRIMACK RIVER SITES:

 

12.  Mer  600  Above Amoskeag Dam, Manchester  7.87

13.  Mer  590  Arms Park, Manchester  8.53

14.  Mer  570  Goffs Falls, Litchfield  7.96

15.  Mer  560  Depot Street, Merrimack   7.89

16.  Mer  550  Upstream of Souhegan River, Merrimack   7.74

17.  Mer  540  Thorntons Ferry, Merrimack  7.66

18.  Mer  530  Greeley Park, Nashua  7.78

19.  Mer  520  Taylors Falls Bridge, Nashua   7.51

20.  Mer  510  Sagamore Bridge, Hudson  7.34

21.  Mer  500  Pheasant Lane Mall, Hudson   NA

22.  Mer  490  Upstream of Tyngsboro Bridge  7.56

 

                                   

                                               

Flow on Upper Souhegan (West Milford) was 61 cubic feet per second; expected flow for that date is 30 cfs.

Flow on Lower Souhegan (Merrimack) was 82 cubic feet per second; historic flow for that date is 51 cfs.

Flow on Merrimack was 7180 cubic feet per second; historic flow for that date is 1770 cfs.

RAINFALL – rain, heavy at times, Sunday and Monday

Temperatures – Souhegan 20C; Merrimack 23C