Merrimack watershed bacteria results: July 16, 2024
Dear river and watershed friends,
July 16, our third sampling day (of six) this summer continues with 100% sampling at 100% of our sites. Thank you, volunteers. We continue to provide you with these bi-weekly reports for eleven sites from Franklin to Bow, comprising the Pemigewasset, Winnipesaukee, Contoocook, and Merrimack Rivers. There were short, flashy rains but nothing that would be affecting these results in a meaningful way. All of the volunteers noted clear water colour at every site.
We know that you have heard it before but it’s important to remember that the results shown below are the probable number of E. coli colonies for every 100 millilitres (ml) of water at that moment in time. We call it a snapshot because conditions at that moment are represented and anything that happened a day or so before or after this sampling date can change drastically. All warm blooded animals (including we humans) have E. coli in their guts. That means that bacteria are an indicator that poop has found its way to the water. This could be a result of stormwater runoff, failed septic systems, mis-connected pipes that are meant to transport household waste to a treatment plant, pet or wildlife waste from river watershed, and other sources.
To protect public health, State of New Hampshire designated swim beaches are not allowed to exceed 88 colonies of E. coli per 100ml. Class B waters (all of our sites are designated as Class B) shall not exceed 406 colonies. These designations do not always reflect real-time water quality. The designation indicates what uses, e.g., swimming, fishing, should be supported by maintaining water quality.
Sample results are very low with all sites meeting the Standard for designated swim areas, as well as the less stringent Class B Standard. On July 2, Site 11 had a spike, which has resolved. We suspect it was from the waterfowl congregating. We continue to stress that these samples are snapshots in time, and something can happen right before or right after volunteers take these samples. These data are important for trend analysis and to help us understand correlations between weather and bacteria counts. Leonardo da Vinci said it best, “When you put your hand in a flowing stream, you touch the last that has gone before and the first of what is still to come.”
You hear us say often, “When it rains, it’s poor,” which means that you may wish to wait a day or so after it rains before recreating in a surface water.
Here are the details.
| Site number and description | results |
| #1 Pemigewasset at Route 3, Franklin | 10 |
| #2 Winnipesaukee at Trestle, Franklin | 41 |
| #3 Merrimack R. above FWWTF, Franklin | 41 |
| #4 Merrimack R. below FWWTF, Franklin | <10 |
| #5 Merrimack at Jamie Welch, Boscawen | 10 |
| #6 Merrimack at US Route 4, Canterbury | 31 |
| #7 Contoocook at Rivco, Penacook | 52 |
| #8 Merrimack at Sewalls Falls, Concord | 10 |
| #9 Merrimack at Manchester St., Concord | 30 |
| #10 Merrimack at Blue Seal, Bow | 10 |
| #11 Merrimack at Garvins Falls, Bow | <10 |
Please join us inrecognizing and thanking our Adopt-a-River Site Sponsors that make this work possible (listed in order of their sponsored sites 1-11).
Watts Regulator / Webster Valve
Franklin Savings Bank
Winnipesaukee River Basin Program (two sites)
Elektrisola
Nelson Analytical
Essex Hydro
Aries Engineering
GZA Environmental
Granite Shore Power (two sites)
Our gratitude to Franklin Waste Water Treatment Plant for their continued support, including covering sample processing costs, and providing a safe and convenient drop-off area. The Department of Health and Human Services Public Health Laboratory do a wonderful job processing our samples with prompt results. Thank you, Chantal McGuire for your sample courier-ing from Franklin to Concord.
Did you know that the Upper Merrimack Monitoring program is staffed and managed 100% by volunteers? This means that throughout the year, volunteers organize and perform activities including water sampling, collecting benthic macroinvertebrates to gauge long-term river health, and work nights in a laboratory to identify those “bugs?” If you want to learn more or get involved, please contact Michele and Steve (see below for contact information).
Volunteers will take their next samples on Tuesday, July 30, 2024.
Please visit our forum at MerrimackRiver.org/forum and the Upper Merrimack Watershed Association site MerrimackRiver.org for further information. Don’t hesitate to contact us at UMMP@MerrimackRiver.org or 603.796.2615 (landline) should you have any questions.
Sincerely,
Michele L Tremblay Stephen C Landry
Program Manager Sampling Supervisor