June 2, 2015

RIVER MONITORING BEGINS WITH WET WEATHER

After weeks of very dry weather, rain showed up in time for the first water quality monitoring of the 2015 season. Normally heavy rains that come after a period of dry weather provide higher than normal E. coli bacteria counts. And this is what monitors found when they tested early Tuesday morning. Counts on the Merrimack River were in the 1000 range; and on the Souhegan River in the 2000 range, very high, dangerous levels.

E. coli bacteria in the water are an indicator for problems for bathers, less so for the health of the river itself. A level of 88 bacteria colonies per 100 ml is the threshold for closing public swimming beaches in NH. This is the standard that SWA uses although there are no public beaches on either river in our area. A level between 88 and 126 is still acceptable for swimming but cases of swimmers ear and gastrointestinal problems may occur in susceptible bathers. A level higher than 126 is not recommended for swimming, and a level higher than 406 is dangerous. Both rivers tested much higher than the dangerous level.

The month of May had virtually no rain and then we had three inches of rain in the two days before the tests. This washed all of the normal pollution off the banks into the water all at once and the E. coli counts soared. George May, president of the SWA and coordinator of the testing program, pointed out that this is normal and “kids should stay out of the rivers for several days after any heavy rains. Lakes usually have less of a problem.”

The testing is performed by trained volunteers with the Souhegan Watershed Association. This is the 19th year that SWA has been doing these tests. Generally water quality has improved over that span of testing – especially in the Merrimack River according to May. “Typically at this time the Merrimack River tests substantially below the threshold of E. coli bacteria that would indicate any concern for swimming in the river. This week, however, that is not the case.”

Both rivers showed excellent levels of dissolved oxygen, the amount of oxygen available for animal and insect life in the river and the best indicator of the overall health of the river. The Souhegan had an average level of 10 mg/L, a very high, excellent level. The Merrimack is dammed up throughout its course and so becomes a series of ponds which have lower DO levels. The Merrimack still had an average over 8 mg/L, which is quite excellent. As the summer develops, oxygen levels will naturally drop, but both rivers have historically over the last twenty years of testing have shown very acceptable DO levels all season long.

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.

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

The next test will be done on June 16.

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.

Here are the E. coli results for tests on June 2nd:

SOUHEGAN RIVER SITES:

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

  2. SoR 333 Water Loom Pond, New Ipswich 123.6

  3. SoR 320 Highbridge, New Ipswich 547.5

  4. SoR 309 Above Greenville Mill Pond, Greenville 1553.1

  5. SoR 296 Downtown Greenville upstream of WWTP 1119.9

  6. SoR 291 Green Bridge off Rte 31 below Greenville WWTP 866.4

  7. SoR 218 Below the Horseshoe, Wilton 2419.6

  8. SoR 210 Downtown Wilton NA

  9. SoR 201 Pine Valley Mill, West Milford >2419.6

  10. SoR 170 Behind Hayward Field, West Milford 1732.9

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

  12. SoR 146 Swing Bridge, Milford 2419.6

  13. SoR 133 Riverside Cemetery, Milford >2419.6

  14. SoR 130 Behind Lorden Plaza, Milford NA

  15. SoR 122 Amherst Country Club >2419.6

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

  17. SoR 095 Boston Post Road Canoeport, Amherst 1553.1

  18. Sor 070 Seaverns Bridge, Merrimack 1119.9

  19. SoR 057 Indian Ledges, Merrimack 1732.9

  20. SoR 034 Turkey Hill Bridge, Merrimack 1413.6

  21. SoR 001 Watson Park, DW Hwy, Merrimack 488.4

MERRIMACK RIVER SITES:

1. Mer 600 Above Amoskeag Dam, Manchester 62.0

2. Mer 590 Arms Park, Manchester >410.6

3. Mer 570 Goffs Falls, Litchfield 62.0

4. Mer 560 Depot Street, Merrimack 1986.3

5. Mer 550 Upstream of Souhegan River, Merrimack 1046.2

6. Mer 540 Thorntons Ferry, Merrimack NA

7. Mer 530 Greeley Park, Nashua 579.4

8. Mer 520 Taylors Falls Bridge, Nashua 517.2

9. Mer 510 Sagamore Bridge, Hudson 686.7

10. Mer 500 Pheasant Lane Mall, Hudson NA

11. Mer 490 Upstream of Tyngsboro Bridge 1413.6

Flow on Upper Souhegan was 636 CFS and expected flow for that date is 115

Flow on Lower Souhegan was 409 CFS and historic flow for that date is 191

Flow on Merrimack was 6240 CFS and historic flow for that date is 4900

RAINFALL - Sat overcast, Sun and Monday heavy rain -3”.

Water temperatures: Souhegan 16C; Merrimack 20C

DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON JUNE 2, 2015

SOUHEGAN RIVER SITES:

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

  2. SoR 333 River Road above Water Loom Pond, New Ipswich 7.59

  3. SoR 320 Highbridge, New Ipswich 9.49

  4. SoR 309 Above Greenville Mill Pond, Greenville 9.59

  5. SoR 296 Downtown Greenville upstream of WWTP 9.82

  6. SoR 291 Green Bridge off Rte 31 below Greenville WWTP 9.81

  7. SoR 218 Below the Horseshoe, Wilton 10.59

  8. SoR 210 Downtown Wilton NA

  9. SoR 201 Pine Valley Mill, West Milford 10.7

  10. SoR 170 Behind Hayward Field, West Milford 10.22

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

  12. SoR 146 Swing Bridge, Milford 10.25

  13. SoR 133 Riverside Cemetery, Milford 10.46

  14. SoR 130 Behind Lorden Plaza, Milford NA

  15. SoR 122 Amherst Country Club 10.37

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

  17. SoR 095 Boston Post Road Canoeport, Amherst 9.77

  18. Sor 070 Seaverns Bridge, Merrimack 9.64

  19. SoR 057 Indian Ledges, Merrimack 10.11

  20. SoR 034 Turkey Hill Bridge, Merrimack 9.7 (DUP 9.69)

  21. SoR 001 Watson Park, DW Hwy, Merrimack 10.34

MERRIMACK RIVER SITES:

12. Mer 600 Above Amoskeag Dam, Manchester 8.37

13. Mer 590 Arms Park, Manchester 8.87

14. Mer 570 Goffs Falls, Litchfield 8.78

15. Mer 560 Depot Street, Merrimack 8.41

16. Mer 550 Upstream of Souhegan River, Merrimack 8.34

17. Mer 540 Thorntons Ferry, Merrimack NA

18. Mer 530 Greeley Park, Nashua 8.24

19. Mer 520 Taylors Falls Bridge, Nashua 7.75

20. Mer 510 Sagamore Bridge, Hudson 8.08

21. Mer 500 Pheasant Lane Mall, Hudson NA

22. Mer 490 Upstream of Tyngsboro Bridge 7.52

Flow on Upper Souhegan was 636 cubic feet per second; expected flow for that date is 115 cfs.

Flow on Lower Souhegan was 409 cubic feet per second; historic flow for that date is 191 cfs.

Flow on Merrimack was 6240 cubic feet per second; historic flow for that date is 4900 cfs.

RAINFALL – Sat clear; Sun & Mon 3+ inches. Drizzle Tues am.

Water temperatures: Souhegan 16C; Merrimack 20C