Bacteria days are here again: results for June 15, 2017

Dear River and Watershed Friends,

Good news: on our very first day of the season we not only had 100% sampling at 100% of our sites but the E. coli bacteria readings from yesterday are very low.

None of the eleven samples taken yesterday, June 15, 2017, from the Pemigewasset and Winnipesaukee Rivers in Franklin to the the mainstem Merrimack in Bow had levels exceeding 46.4 colonies of E. coli bacteria for every 100 millilitres of water. That’s great news for your weekend because designated swim beaches are not allowed to exceed 88 colonies and Class B waters (all of our sites are Class B waters) should be below 406 colonies. Here are the details.

Site number and description
1 Pemigewasset 29.2
2 Winnipesaukee 23.1
3 Merrimack above FWWT Plant 21.6
4 Merrimack below FWWT Plant 46.4
5 Merrimack Jamie Welch Park 21.1
6 Merrimack Route 4 Bypass 28.8
7 Contoocook at Rivco 20.1
8 Merrimack Sewalls Falls 26.2
9 Merrimack Manchester St 18.9
10 Merrimack Blue Seal 21.8
11 Merrimack Garvins Falls 13.1

If you are interested, here are the flows from yesterday juxtaposed with summer median flows for the four larger rivers on which we take water samples (cfs = cubic feet per second).

Winnipesaukee River

  • UMMP sample day = 1290 cfs
  • Summer median = 518 cfs

Pemigewasset River

  • UMMP sample day = 679
  • Summer median = 740

Contoocook River

  • UMMP sample day = 509 cfs
  • Summer median = 565 cfs

Merrimack River

  • UMMP sample day = 2710 cfs
  • Summer median = 1970 cfs

The flows for some of our rivers are pretty high with others approaching their summer norms or are below them. How does that affect water quality? The old saying is, “Dilution is the solution to pollution.” If we had taken these samples right after a big rain storm, we might be saying “When it rains; it’s poor.” That is because right after a large rain, nutrients including runoff from failed septic systems, wildlife, and pet waste, flow right into brooks and rivers.

Our next sampling day is Thursday, June 29, 2017 so you will hear from us on June 30.

Thank you to our wonderful Adopt-a-River Site sponsors, sample courier, site volunteers, Adopt-a-River Site sponsors, and the crew at Franklin Waste Water Treatment Plant. There would be no Upper Merrimack Monitoring Program without them.

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Michele L Tremblay                          Stephen C. Landry
Program Manager                             Sampling Supervisor