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  • File photo by Bob Hammerstrom

    David Brooks takes a water sample from the Souhegan River in Amherst Tuesday, June 8, 2010.
  • File photo by Bob Hammerstrom

    A sampling bag used to collect water from the Souhegan River for testing for E. coli bacteria.
  • Staff photo by Bob Hammerstrom

    David Boucher, assistant superintendant of the Milford Wastewater Treatment Department shows how water samples from the Souhegan River are tested. They "wells" of water turn yellow in the presence of bacteria. Tuesday, June 8, 2010.
  • File photo by Bob Hammerstrom

    Telegraph writer David Brooks writes down data after taking a water sample from the Souhegan River in Amherst, Tuesday, June 8, 2010.
  • File photo by Bob Hammerstrom

    Telegraph writer David Brooks twirls a bag containing a water sample in the Souhegan River near Route 122 on June 8, 2010.
  • Staff photo by Bob Hammerstrom

    Telegraph writer David Brooks heads down a path to the Souhegan River Tuesday, June 8, 2010, to collect a water sample for testing e-coli bacteria.


Friday, June 11, 2010

Volunteers turn citizen scientists

There are plenty of good reasons to wander down to a riverbank at 8 o’clock on a beautiful morning. One of them, it turns out, is to find e. coli bacteria.

That microbe-seeking activity brought more than 20 volunteers, including me, to the Merrimack and Souhegan rivers on Tuesday morning – which was, by the way, absolutely gorgeous – to kick off the 14th season of what may be the state’s most successful volunteer water-monitoring program.

Each of us dipped a glass bottle under water, pointing it downstream and making sure it was free of air before sealing it with a glass stopper and a plastic cap. Then we filled a separate plastic bag with water and twirled it shut, thus justifying its brand name of TwirlPac.

Then came the paperwork. We jotted down air and water temperature, water condition (green? smelly? turbid?) and any nearby items of interest (swimmers? ducks? remote-controlled submarines?).

Finally, we gathered up our findings and samples and took them to the nearest wastewater treatment plant, where they are tested for e.coli bacteria and dissolved oxygen. In two weeks we’ll do it again – at 8 a.m. every other Tuesday through September.

The whole water-monitoring project is overseen by the Souhegan Watershed Association and Lower Merrimack River Local Advisory Committee, and in a rarity for environmental programs, it has produced happy news.

“Generally speaking, the rivers are in pretty good shape,” said George May of Merrimack, SWA president and long-time leader of the project.

Not only do they show that it is usually safe to swim in the Souhegan River and the Merrimack River – at least from Manchester through Tyngsborough, Mass., where the samples are taken – but they have also gotten better over the years, as runoff is contained and sewage releases ended.

“Public education seems to work,” said May. He pointed to a farmer in New Ipswich that the Souhegan Watershed Association contacted after sampling near his fields.

“We were finding feces in the water, so we talked to him. He said, ‘OK, I won’t spread manure quite so close to the river,’ and it got better,” said May.

As another example, he pointed to the discovery by a sampler that a toilet in Wilton was emptying into the river. Authorities were notified, and the problem was fixed.

Organizing volunteers to perform data collection in the field, so-called “citizen science,” has become reasonably common in the research world.

New Hampshire’s Department of Environmental Services, for example, oversees a similar program called Volunteer River Assessment Program (VRAP), established in 1998 to help gather season-long data on the quality of New Hampshire rivers. (There’s also VLAP, for lake assessment.)

My family has been collecting Souhegan River water sample for several years from a canoeport alongside Route 122, surrounded by the Amherst Country Club golf course, but until this week I didn’t know how this vial of water turns into the “bacteria colonies per 100 milliliters” count that determines whether I should worry if I fall into river and swallow some of it while getting the same.

Our samples go to the wastewater treatment plant in Milford, where Susan Snyder, who oversees the lab, poured the TwirlPac water into an ingenious device called a Quanti-tray, which separates it into numerous little covered plastic “wells.”

When reagents are added to the water, wells turn yellow if they contain coliform bacteria, which is common and usually benign, and when the tray is placed under ultraviolet light, wells glow like a velvet Elvis poster if they contain e. coli bacteria, which in excess amounts can be dangerous. Counting the colored wells produces a snapshot on the river’s cleanliness.

“This is much easier and faster, and more accurate, than the old method,” said Assistant Superintendent David Boucher, looking back on the old days (pre-2008) of pouring water through filters and counting specks through a microscope.

Milford doesn’t measure levels of dissolved oxygen – one of the basic parameters of the health of a river. Water samples are also tested at Nashua’s and Manchester’s water treatment plants, using commercial devices that determine the amount of oxygen in samples either by sending electrical signals through the water or by shining light through it; in both systems, the resulting signal is altered in complicated ways by the concentration of oxygen.

There are plenty of other things that can be measured in a river.

The obvious one is the water flow, which is tracked by automatic measuring devices maintained by the National Oceanographic and Atmospheric Administration. The U.S. Geological Survey has long had two monitoring stations on the Merrimack, including one near the Massachusetts border in Nashua, and one on the Souhegan River near its mouth in Merrimack. May says another has been added to the Souhegan in west Milford.

Another common measurement is phosphorus levels, which is a good sign of material washing into the river. Until two years ago we measured those with a color-changing paper stick, estimated the result against a printout, but this proved to be more than amateurs could handle well; the results weren’t consistent or accurate enough to be worth the cost and it was dropped.

This reflects a problem with depending on untrained amateurs to collect data: You can’t count on us to do anything too complicated.

For example, occasionally samplers will neglect to get rid of all the bubbles from the glass jar, which ruins dissolved oxygen measurement, and last year I was scolded – albeit gently – for not collecting enough water in my TwirlPac to allow good e. coli measurements.

Despite those shortfalls, though, the water-monitoring project remains a great success. I’m happy to be part of it, even when the mosquitoes bite and my boots leak and it rains. Life is too short not to be made uncomfortable in a good cause, once in a while.

If you’d like to join, contact May (georgemay@comcast.net) or Karen Mattor (kare mattor@gmail.com).

David Brooks can be reached at 594-5831 or dbrooks@ nashuatelegraph.com.