June 22: Mixed results on first day of summer
Water quality monitors on the Souhegan and Merrimack Rivers noted all kinds of summer activities on the first full day of summer. Swimmers, boaters, fishermen were all noted early Tuesday morning. Monitors noted that the water temperatures were higher than the air temperatures around 8am that morning. And many noted lots of small salmon fry at their test sites along the Souhegan. A couple of larger fish were also noted trying to get through the very shallow water coming into the Souhegan from the Merrimack River.
Birds of all types were flying around.
Unfortunately a few monitors also reported an oily sheen on the water, slight septic smells in a couple of locations, and a possible area of milfoil near the Tyngsborough Bridge.
E. coli results were mixed. The Merrimack River between Manchester and Tyngsborough had very low bacteria counts with one exception near the Tyngsborough Bridge. The count there tied for the worst this week - seen just upstream of the Milford Oval on the Souhegan. The Merrimack River may have been an aberration; the high count on the Souhegan was not.
The upper section of the Souhegan from New Ipswich through Wilton had very good results, but from Milford through Amherst the E. coli counts generally increased to unacceptable levels. The highest count, 326, was seen near the Souhegan Valley Boys and Girls Club just upstream of the Milford Oval. This section of the river usually has higher counts than the upstream section because of its warmer, sandy, shallow, slow-moving nature. The monitoring program uses 88 as the acceptable E. coli level; levels higher than this can cause swimmer’s itch, eye and ear infections, and diarrhea in some people. Levels higher than 88 cause a public swimming beach to be closed until levels decrease. There are no public swimming areas on either river; however, there are several places frequently used by swimmers. A couple of these had higher than 88 counts – the Amherst Canoeport on Boston Post Road tested at 194 and Turkey Hill Bridge tested at 145. The Horseshoe in Wilton was a very acceptable 18.
All of the dissolved oxygen levels on both rivers came in as very good. Most all were in the 8-9 range. Dissolved oxygen is needed for healthy fish who get their oxygen from the water. Volunteer monitors also note air and water temperatures and various observations at the 20 sites along the entire length of the Souhegan and 11 sites along the Merrimack every other Tuesday morning through September. The lab testing is performed by certified personnel at the Milford, Merrimack, and Nashua Wastewater Treatment Facilities. There are still openings for anyone who would like to volunteer to join the program. Information and past results are available on the Souhegan River website.
Flow on Upper Souhegan was 34CFS and expected flow for that date is 30.
Flow on Lower Souhegan was 72CFS and historic flow for that date is 108.
Flow on Merrimack was 1880 CFS and historic flow for that date is 2700.
Rainfall: Some rain on Sunday; otherwise clear.
Here are the E. coli results for all of the sites tested on June 22. The next test will be on July 6.
SOUHEGAN RIVER SITES:
Billy Ward Pond, Ashburnham NA
SoR 333 River Road above Water Loom Pond, New Ipswich NA
SoR 320 Highbridge, New Ipswich 8
SoR 309 Above Greenville Mill Pond, Greenville NA
SoR 296 Downtown Greenville upstream of WWTP 14
SoR 291 Green Bridge off Rte 31 below Greenville WWTP 45
SoR 218 Below the Horseshoe, Wilton 18
SoR 210 Downtown Wilton NA
SoR 201 Pine Valley Mill, West Milford 96
SoR 170 Behind Hayward Field, West Milford 135
SoR 155 Souhegan Valley Boys and Girls Club, Milford 326
SoR 146 Swing Bridge, Milford 166
SoR 133 Riverside Cemetery, Milford 194
SoR 130 Behind Lorden Plaza, Milford 108
SoR 122 Amherst Country Club 121
SoR 116 Amherst Conservation land Fairway Road, Amherst 140
SoR 095 Boston Post Road Canoeport, Amherst 194
SoR 057 Indian Ledges, Merrimack 40
SoR 034 Turkey Hill Bridge, Merrimack 145
SoR 001 DW Hwy, Merrimack 51
MERRIMACK RIVER SITES:
1. Mer 600 Above Amoskeag Dam, Manchester NA
2. Mer 590 Arms Park, Manchester NA
3. Mer 570 Goffs Falls, Litchfield 18
4. Mer 560 Depot Street, Merrimack 7
5. Mer 550 Upstream of Souhegan River, Merrimack 26
6. Mer 540 Thorntons Ferry, Merrimack 38
7. Mer 530 Greeley Park, Nashua 33
8. Mer 520 Taylors Falls Bridge, Nashua 40
9. Mer 510 Sagamore Bridge, Hudson 37
10. Mer 500 Pheasant Lane Mall, Hudson NA
11. Mer 490 Upstream of Tyngsboro Bridge 328