Bacteria days: results for July 13, 2017

Dear River and Watershed Friends,

Good news: We had 100% sampling at 100% of our sites yesterday.

The not-so-good news: The E. coli bacteria readings at one of our sites was high. There were suspended solids in the water taken with this sample. This result, unusual for the upper Merrimack River watershed, could be due to an excessive amount of algae. This excess could cause a multi-fold proliferation in bacterial growth. The excess of nutrients can feed bacteria and cause their populations to grow. We are looking into what happened at this site, which is an informal swimming area with a lot of use, including parties. We often see diapers; towels; articles of forgotten, castoff clothing; empty chip bags; and liquor receptacles (including the iconic red Solo plastic keg cups) at the site.

As a reminder,  the readings shown below are the number of E. coli bacteria colonies for every 100 millilitres of water. Warm blooded animals (including humans) all have E. coli in their guts. State 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  Value
1 Pemigewasset* 113.0
2 Winnipesaukee 88.0
3 Merrimack above FWWT Plant 16.0
4 Merrimack below FWWT Plant 37.3
5 Merrimack Jamie Welch Park 39.3
6 Merrimack Route 4 Bypass >2,419.6
7 Contoocook at Rivco 33.6
8 Merrimack Sewalls Falls 24.6
9 Merrimack Manchester St 93.3
10 Merrimack Blue Seal 272.3
11 Merrimack Garvins Falls 26.2

*Laboratory replicate

Our next sampling day is Thursday, July 27, 2017 so you will hear from us on July 28. It will be interesting to see if Site 6 settles down and what data insights the other sites will reveal.

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