Parts of Souhegan River Safe for Swimming

Warmer temperatures and lower flows in the Souhegan and Merrimack Rivers are producing generally expected seasonal E. coli readings in both rivers according to the latest test done by the Souhegan Watershed Association.

The Merrimack River, once again, tested clean for E. coli bacteria throughout the testing range, between Manchester and Tyngsborough. None of the 12 sites tested along the river exceeded the level for swimming beaches in New Hampshire. This has been the story all summer long, and over the last several years as the river has cleaned up nicely.

The Souhegan is a much smaller river and reflects any pollution more quickly. The upper stretch of the river tested OK as far as Wilton, but from Wilton throughMilford and Amherst E. coli counts were in the 200 range. This is well above the 88 limit required for clean beaches and swimmers would be advised to stay out of the water in this stretch until the counts come down. Levels higher than 88 may cause swimmer’s itch, eye and ear infections, and gastrointestinal problems.

However, most of the known swimming holes on the Souhegan tested OK; the only one not meeting the requirement was the Amherst Canoeport on Boston Post Road. The count here was 210. The Horseshoe in Wilton, Indian Ledges, Turkey Hill, and Watson Park all had acceptable levels for swimming.

About thirty Souhegan Watershed Association volunteers collect water samples every two weeks and deliver them to the wastewater treatment plants in Manchester,Greenville, Milford, Merrimack, and Nashua where certified labs process the samples. SWA has been collecting this data for the last 20 years and most of it is available on www.souheganriver.org.

The last scheduled test for this season will be on September 8. The results will be available on the website the following day. The bacteria tests take 24 hours to grow and read the bacteria colonies.

Here are this week’s results. The lower the number the cleaner the river; lower than 88 is excellent.

E-COLI MONITORING RESULTS FOR TESTS TAKEN OdN AUG. 25, 2015

SOUHEGAN RIVER SITES:

1. Billy Ward Pond, Ashburnham #1 2.0, #2 1.0
2. SoR 333 Water Loom Pond, New Ipswich 6.3
3. SoR 320 Highbridge, New Ipswich 70.3
4. SoR 309 Above Greenville Mill Pond, Greenville 151.5
5. SoR 296 Downtown Greenville upstream of WWTP 76.7
6. SoR 291 Green Bridge off Rte 31 below Greenville WWTP 127.4
7. SoR 218 Below the Horseshoe, Wilton 71.2
8. SoR 210 Downtown Wilton NA
9. SoR 201 Pine Valley Mill, West Milford NA
10. SoR 170 Behind Hayward Field, West Milford NA
11. SoR 155 Souhegan Valley Boys and Girls Club, Milford 613.1
12. SoR 146 Swing Bridge, Milford 272.3
13. SoR 133 Riverside Cemetery, Milford 127.4
14. SoR 130 Behind Lorden Plaza, Milford NA
15. SoR 122 Amherst Country Club 235.9
16. SoR 116 Amherst Conservation land Fairway Road, Amherst NA
17. SoR 095 Boston Post Road Canoeport, Amherst 209.8
18. Sor 070 Seaverns Bridge, Merrimack 290.9
19. SoR 057 Indian Ledges, Merrimack 122.3
20. SoR 034 Turkey Hill Bridge, Merrimack 77.6
21. SoR 001 Watson Park, DW Hwy, Merrimack 32.3

MERRIMACK RIVER SITES:

1. Mer 600 Above Amoskeag Dam, Manchester 10.8

2. Mer 590 Arms Park, Manchester 52.0

3. Mer 570 Goffs Falls, Litchfield 60.9

4. Mer 560 Depot Street, Merrimack NA

5. Mer 550 Upstream of Souhegan River, Merrimack 31.3

6. Mer 540 Thorntons Ferry, Merrimack 24.6

7. Mer 530 Greeley Park, Nashua 19.9

8. Mer 520 Taylors Falls Bridge, Nashua 13.4

9. Mer 510 Sagamore Bridge, Hudson 17.1

10. Mer 500 Pheasant Lane Mall, Hudson NA

11. Mer 490 Upstream of Tyngsboro Bridge NA

Flow on Upper Souhegan was 23 CFS and expected flow for that date is 37

Flow on Lower Souhegan was 38 CFS and historic flow for that date is 41

Flow on Merrimack was 1300 CFS and historic flow for that date is 1330

RAINFALL - Showers Sunday-Monday

Temperatures: Souhegan 22C; Merrimack 23C