Of a Different Nature: High water and pollutants
by Michele L. Tremblay
July 2013

“Water, water, every where,
Nor any drop to drink.”

…so Samuel Taylor Coleridge wrote in The Rime of the Ancient Mariner, who recounted an experience from a long sea voyage becalmed with freshwater supplies dried up.

Here in New Hampshire, there is nearly always access to plenty of freshwater and the last several weeks have brought nearly historically high levels of rain to the Granite State. Many residents and visitors have noticed that the swollen ponds and swift moving rivers are brown and murky. Does that mean that water is dirty? Is there a drop to drink?
To answer that question: start at the top—the top of the watershed. Think of all of that land uphill from a river or pond as a big, spongy funnel. The sponge soaks up everything including waste from septic systems that aren’t working properly, pet waste, fertilizers, and car oil. That’s a pretty dirty sponge. When rain falls or snow melts, the dirty sponge soaks up water and eventually can’t absorb any more. All of that water funnels down to rivers and ponds and creates runoff, which is also called nonpoint source pollution. This runoff carries to the nearest brook, pond, or river everything that was on our driveways, rooftops, lawns, fields, and woods.
“Nonpoint source is everyone’s business because we all create it,” said Stephen Landry, Merrimack Watershed Supervisor at the New Hampshire Department of Environmental Services, “Whether we are using a septic system on a daily basis, washing cars on driveways, or fertilizing lawns—everything—it all becomes runoff.” Landry said that managing stormwater runoff should start on home lots. The key is to keep that runoff on the land and not letting it flow on to roads and into storm drains. The State recognizes fifteen types of nonpoint source pollution with stormwater runoff as the largest contributor and threat to water quality in New Hampshire. “Chances are there are a lot of pollutants along for the ride including viruses, bacteria, and other disease causing organisms,” said Landry.

High flows from rain and snowmelt often bring with them high levels of E. coli, a species of bacteria found in the intestines or warm-blooded animals. Programs that monitor water quality often use E. coli as a measure or indicator that fecal matter has entered a river or pond, usually via a failed septic system, illegal discharge pipes, or animal waste in soil. That metal grated hole in the road near your house isn’t a sewer, it’s a storm drain and anything that goes into it ends up untreated and into the nearest brook, river, or pond.

In New Hampshire, Class B waters should be safe for swimming, boating, fishing, and drinkinge (with treatment). Class B waters, including the Merrimack River, must meet the established standard of no more than 406 colonies of E. coli in each 100 milliliters of water. For designated swimming beaches such as those found in state parks and campgrounds, the standard is much higher: no more than 88 colonies per 100 milliliters. It’s important to remember that the classifications are not a rating of how good is the water in a river or pond but what it should be.
During the week of July 8, 2013, the Upper Merrimack Monitoring Program’s volunteers collected samples on the Pemigewasset, Winnipesaukee, Contoocook, and Merrimack Rivers from Franklin to Bow. The Franklin Waste Water Treatment Plant analyzed the eleven samples. The bacteria levels ranged from a low of 60 to a high of 727 colonies per 100 milliliters—that’s nearly double the standard of 406.
So what’s a Merrimack watershed citizen to do?

  1. Get your septic system pumped checked at least every three years to avoid costly repairs and assure that your waste doesn’t end up in the nearest stream or pond.
  2. Test soils before applying fertilizers or other materials. You might be surprised to see that you don’t have to spend money on chemicals and that leaving lawn clippings or composted leaves is all the fertilizer you need.
  3. Try out the tools developed by the Department of Environmental Services and the Lake Winnipesaukee Watershed Association that calculate figure out whether your property is contributing to runoff. There are great tips on creating rain gardens or using gutters and rain barrels that save money while keeping stormwater on site.

So next time you are planning a swim in your favorite pond or river remember, “When it rains, it’s poor,” and maybe wait a couple of days before taking the plunge.

You can learn more (and have fun) with these selected resources
Upper.Merrimack Monitoring Program

Water quality standards information

Winnipesaukee residential runoff reduction model (Beta version)

Stormwater Management for Homeowners: New Hampshire Residential Loading Model (Beta vrersion)

The Rime of the Ancient Mariner