June 14
UNEXPECTED E. COLI LEVELS
Unusually high E. coli levels showed up in the Souhegan River for the first water quality tests for the 2016 season. The headwaters and the mouth of the river tested OK but the middle section of the river from Wilton to Amherst tested at levels that made it unsuitable for swimming. Watson Park at the mouth of the river in Merrimack tested good at 63.7.
Levels lower than 88 are excellent; between 88 and 126 is acceptable for swimming but susceptible bathers could experience problems. Levels higher than 126 are not recommended for swimming. Swimmers ear and gastrointestinal problems may occur at those levels.
The Merrimack between Manchester and Tyngsborough tested excellent for E. coli. Water from the Souhegan raised the readings slightly as it entered the Merrimack, but the much larger flow in the Merrimack diluted the pollution enough so it never reached the 88 E. coli level. This has been typical of the Merrimack River in the last several years. Unless there is heavy rainfall, the E. coli counts on the Merrimack stay excellent.
This is the 20th year that the Souhegan Watershed Association volunteers have been monitoring both of these rivers. SWA tests for E. coli to determine the pollution levels that might affect humans and dissolved oxygen to determine the overall health of the river for fish and habitat. All of the test results are available at their website at www.souheganriver.org. Past years are also listed. SWA does not test for other chemical pollution that might exist. PFOA, PCBs, and creosote have shown up in the rivers and are being monitored by EPA.
The dissolved oxygen levels in both rivers tested as excellent. The levels should be high now at the beginning of the season and they will gradually diminish during the hot summer, but they are almost perfect right now. This test really indicates the basic health of the river itself.
The higher E. coli in the Souhegan may be attributed to the low flow right now. Also there were light showers much of Saturday that washed pollution into the river; E. coli bacteria generally live for three days. The low flow doesn’t provide much dilution to inflow from storm drains and parking lots in Wilton and Milford.
The rivers will be tested again every two weeks during the summer. Thirty volunteers, many of whom have been with the program for many years, adopt a site and test every other Tuesday morning and carry the samples to the local wastewater treatment plants in Greenville, Milford, Merrimack, Manchester and Nashua where the samples are processed by licensed professionals. There are still sites available and new volunteers are always welcome; sites with NA are open right now. More information is available on the SWA website.
The next test will be on June 28.
Here are the results for the test on June 14:
E-COLI MONITORING RESULTS FOR TESTS TAKEN ON JUNE 14, 2016
SOUHEGAN RIVER SITES:
1. Billy Ward Pond, Ashburnham #1 1.0; #2 <1.0
2. SoR 333 River Road above Water Loom Pond, New Ipswich NA
3. SoR 320 Highbridge, New Ipswich 53.8
4. SoR 309 Above Greenville Mill Pond, Greenville 29.5
5. SoR 296 Downtown Greenville upstream of WWTP 27.2
6. SoR 291 Green Bridge off Rte 31 below Greenville WWTP 52.9
7. SoR 218 Below the Horseshoe, Wilton NA
8. SoR 210 Downtown Wilton 290.9
9. SoR 201 Pine Valley Mill, West Milford NA
10. SoR 170 Behind Hayward Field, West Milford 172.3
11. SoR 155 Souhegan Valley Boys and Girls Club, Milford 178.5
12. SoR 146 Swing Bridge, Milford 214.3
13. SoR 133 Riverside Cemetery, Milford 122.3
14. SoR 130 Behind Lorden Plaza, Milford 131.4
15. SoR 122 Amherst Country Club 146.7
16. SoR 116 Amherst Conservation land Fairway Road, Amherst NA
17. SoR 095 Boston Post Road Canoeport, Amherst 149.7
18. SoR 057 Indian Ledges, Merrimack NA
19. SoR 034 Turkey Hill Bridge, Merrimack 101.4
20. SoR 004 Watson Park, Merrimack 63.7
MERRIMACK RIVER SITES:
1. Mer 600 Above Amoskeag Dam, Manchester 13.4
2. Mer 590 Arms Park, Manchester 27.5
3. Mer 580 Upstream of Piscataquag River, Manchester NA
4. Mer 570 Goffs Falls, Litchfield 25.9
5. Mer 560 Depot Street, Merrimack 43.5
6. Mer 550 Upstream of Souhegan River, Merrimack 72.3
7. Mer 540 Thorntons Ferry, Merrimack 62.0
8. Mer 530 Greeley Park, Nashua 46.4
9. Mer 520 Taylors Falls Bridge, Nashua 76.7
10. Mer 510 Sagamore Bridge, Hudson 73.3
11. Mer 500 Pheasant Lane Mall, Hudson NA
12. Mer 490 Upstream of Tyngsboro Bridge 38.4
Flow on Upper Souhegan was 13 CFS and expected flow for that date is 123
Flow on Lower Souhegan was 95 CFS and historic flow for that date is 132
Flow on Merrimack was 2450 CFS and historic flow for that date is 3620
RAINFALL: light showers on Saturday; otherwise clear, cool
DISSOLVED OXYGEN RESULTS FOR TESTS TAKEN ON JUNE 14, 2016
(You can check http://www.souheganriver.org/results.html for more info about DO)
SOUHEGAN RIVER SITES:
1. Billy Ward Pond, Ashburnham #1 8.53; #2 8.43
2. SoR 333 Water Loom Pond, New Ipswich 8.30
3. SoR 320 Highbridge, New Ipswich 9.09
4. SoR 309 Above Greenville Mill Pond, Greenville 8.90
5. SoR 296 Downtown Greenville upstream of WWTP 9.11
6. SoR 291 Green Bridge off Rte 31 below Greenville WWTP 9.29
7. SoR 218 Below the Horseshoe, Wilton NA
8. SoR 210 Downtown Wilton 10.03
9. SoR 201 Pine Valley Mill, West Milford NA
10. SoR 170 Behind Hayward Field, West Milford 8.96
11. SoR 155 Souhegan Valley Boys and Girls Club, Milford 8.51
12. SoR 146 Swing Bridge, Milford 8.63
13. SoR 133 Riverside Cemetery, Milford 8.90
14. SoR 130 Behind Lorden Plaza, Milford 8.81
15. SoR 122 Amherst Country Club 8.63
16. SoR 116 Amherst Conservation land Fairway Road, Amherst NA
17. SoR 095 Boston Post Road Canoeport, Amherst 8.34
18. SoR 057 Indian Ledges, Merrimack NA
19. SoR 034 Turkey Hill Bridge, Merrimack 8.35
20. SoR 001 Watson Park, Merrimack 9.57
MERRIMACK RIVER SITES:
1. Mer 600 Above Amoskeag Dam, Manchester 8.45
2. Mer 590 Arms Park, Manchester 9.24
3. Mer 580 Upstream of Piscataquag River, Manchester NA
4. Mer 570 Goffs Falls, Litchfield 8.61
5. Mer 560 Depot Street, Merrimack 8.70
6. Mer 550 Upstream of Souhegan River, Merrimack 4.54
7. Mer 540 Thorntons Ferry, Merrimack 8.37
8. Mer 530 Greeley Park, Nashua 8.74
9. Mer 520 Taylors Falls Bridge, Nashua 8.39
10. Mer 510 Sagamore Bridge, Hudson 8.44
11. Mer 500 Pheasant Lane Mall, Hudson NA
12. Mer 490 Upstream of Tyngsboro Bridge 8.69