Bacteria days: results for July 26, 2018

Dear River and Watershed Friends,

Upper Merrimack Monitoring Program volunteers began the bacteria sampling season with 100% sampling at 100% of the eleven sites on the Merrimack River from Franklin to Bow and on the Pemigewasset, Winnipesaukee, and Contoocook Rivers. This week continued that excellent trend.

Not so excellent: This is the fifth (four this year and one at the end of last year) high reading on the Pemigewasset River. This is particularly disturbing since prolonged periods of rain tend to dilute runoff (also known as nonpoint) sources of bacteria. Local officials are closing in on the source(s) of the bacteria. We continue to work with local and state officials to determine the source(s) of these high E. coli readings.

The rest is good news: All other samples are well within the Class B standard and most are within the Class A standard.

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
1 Pemigewasset 1,413.6
2 Winnipesaukee 145.0
3 Merrimack above FWWT Plant 125.9
4 Merrimack below FWWT Plant 127.4
5 Merrimack Jamie Welch Park 117.8
6 Merrimack Route 4 Bypass 116.2
7 Contoocook at Rivco 47.3
8 Merrimack Sewalls Falls 81.3
9 Merrimack Manchester St 62.7
10 Merrimack Blue Seal 125.9
11 Merrimack Garvins Falls 34.5

You’ll hear from us again after the August 9 sampling day.

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Michele L Tremblay                          Stephen C Landry
Program Manager                             Sampling Supervisor