Test Results Show E. Coli Levels in Merrimack, Souhegan Rivers

A recent report regarding E. coli bacteria in local rivers showed significant differences between E. coli bacteria in the Merrimack and Souhegan Rivers.

The tests were conducted by volunteers of the Souhegan Watershed Association biweekly during the summer and lab tests are performed by personnel at waste water treatment plans in Nashua, Merrimack, Milford and Manchester.

The Merrimack River was the clear winner, according to a report from the Souhegan Watershed Association. Bacteria levels between Manchester and Tyngsborough were far below the 88 level required for public swimming areas in New Hampshire, the report said.

The Souhegan River’s upstream and downstream reaches both tested clean. The middle of the river, however, showed “dangerously high” counts, according to the report. The Souhegan River tested well until it reached Wilton, where the river tested near 1,000, “very high, very dangerous.”

The pollution was diluted through West Milford, however counts remained too significant for human use. Counts spiked up again once the river reached the Oval area, according to the report. The count was 550 near the Swing Bridge.

Despite high counts in some locations, many swimming holes along the Souhegan River were suitable for human use.

While the Souhegan tested high in certain locations, the Merrimack River tested very cleanly, the report said. As it has for several years, the Merrimack tested very clean for bacteria and dissolved oxygen.

>> Read the entire report here.

Here are the results for E. coli monitoring tests taken on Tuesday, Aug. 11, from the Souhegan Watershed Association (the lower the number the better).

Souhegan River sites:

• Billy Ward Pond, Ashburnham #1 32.7, #2 4.1
• SoR 333 Water Loom Pond, New Ipswich 2.0
• SoR 320 Highbridge, New Ipswich 78.9
• SoR 309 Above Greenville Mill Pond, Greenville 67.0
• SoR 296 Downtown Greenville upstream of WWTP 36.9
• SoR 291 Green Bridge off Rte 31 below Greenville WWTP 37.4
• SoR 218 Below the Horseshoe, Wilton NA
• SoR 210 Downtown Wilton 980.4
• SoR 201 Pine Valley Mill, West Milford 461.1
• SoR 170 Behind Hayward Field, West Milford NA
• SoR 155 Souhegan Valley Boys and Girls Club, Milford 488.4
• SoR 146 Swing Bridge, Milford 547.5
• SoR 133 Riverside Cemetery, Milford 196.8
• SoR 130 Behind Lorden Plaza, Milford 114.5
• SoR 122 Amherst Country Club 79.4
• SoR 116 Amherst Conservation land Fairway Road, Amherst NA
• SoR 095 Boston Post Road Canoeport, Amherst 121.1
• SoR 070 Seaverns Bridge, Merrimack 67.7
• SoR 057 Indian Ledges, Merrimack 33.1
• SoR 034 Turkey Hill Bridge, Merrimack 43.5
• SoR 001 Watson Park, DW Hwy, Merrimack 36.4

Merrimack River sites:

• Mer 600 Above Amoskeag Dam, Manchester 6.3
• Mer 590 Arms Park, Manchester 24.6
• Mer 570 Goffs Falls, Litchfield 22.6
• Mer 560 Depot Street, Merrimack NA
• Mer 550 Upstream of Souhegan River, Merrimack 16.9
• Mer 540 Thorntons Ferry, Merrimack 15.6
• Mer 530 Greeley Park, Nashua 9.8
• Mer 520 Taylors Falls Bridge, Nashua 13.2
• Mer 510 Sagamore Bridge, Hudson 13.4
• Mer 500 Pheasant Lane Mall, Hudson NA
• Mer 490 Upstream of Tyngsboro Bridge 8.6