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The Hippo Press

January 28, 2010

Water world
A look at the Merrimack River

By Jeff Mucciarone jmucciarone@hippopress.com

There was a time when the Merrimack River was basically an open sewer.

And several times per year in Manchester and Nashua, it still is.

Manchester and Nashua operate wastewater treatment plants that treat sewage and stormwater before sending it out into the river. In drier conditions, it’s a healthy system. Besides treating sewage, plants clean up and strain out dirty stormwater that has run off parking lots, roads and walkways and into the gutter. But in particularly wet conditions, treatment facilities can’t handle both the wastewater and the stormwater. In turn, the increased flow triggers a combined sewage overflow (CSO), which sends all the wastewater and stormwater directly into the river ? untreated.

When it’s rainy, drivers on Interstate 293 can see water flowing out of a large white pipe poking out of the riverbank nearby MerchantsAuto.com Stadium. The large cement steps leading out from the pipe are sometimes characterized by a white film. During warmer months, that’s not snow; that’s toilet paper. These overflows are triggered in Manchester about 15 to 20 times per year.

But there are people and organizations across the region working to keep contamination from the sewer as well as other forms of pollution to a minimum and to bring the river a little closer to its pre-Industrial Revolution state — a least in terms of its cleanliness and its ability to support human recreation and animal habitats. The river, which runs from Franklin to the Massachusetts coast, isn’t part of the machinery of the mills anymore, but it is an important part of the region’s landscape. And while there’s still a lot to do to clean up this ecosystem, experts say the river that connects the cities of central southern New Hampshire has come a long way from when its color reflected the dyes used in the mills.

Not snow, but not bad

Like a large portion of rivers in this country, particularly those utilized for industrial purposes at one time or another, the Merrimack River has had its issues. But its waters run much cleaner today than they once did. Today, the health of the river is summed up simply: “When it rains, it’s poor,” said Steve Landry, a biologist with the state Department of Environmental Services, who attributed the quote to Michele Trembly, chairman of the Upper Merrimack River Advisory Committee. When it isn’t raining, Landry says, it’s pretty good.

The untreated wastewater that is one of the major contamination issues is likely to be carrying a whole host of bacteria and contaminants that could affect humans. Biologists usually test for E. coli, which can be more of an indicator of other bacteria than actually harmful itself. (E. coli is present in every person and every animal’s intestines.)

The reality of occasional sewage overflows isn’t pretty, but the reality today is far different from what the reality once was. Any sewage flowing into the river isn’t good news, but it’s only happening in New Hampshire in Manchester and Nashua. In a different era ? prior to the Clean Water Act, which started in 1972 ? every ounce of sewage from communities touching the river found its way into the Merrimack. And so did all the wastewater from factories, most notably mills in New Hampshire. Longtime residents can probably remember a time when people could tell what dyes the mills were running by the color of the river. Aurore Eaton, executive director of the Manchester Historical Society, said that during a walking tour of the Millyard, two older ladies laughed when Eaton talked about the river’s pollution. The pair remembered being able to tell what color dye was being used by the color of the rats.

Environmental officials are pushing to make it so that stormwater no longer flows to the treatment facilities and instead is deposited directly into the river. That’s far from a perfect system. On the one hand, it would mean saying goodbye to CSOs ? no more white film (and other stuff) on the cement steps. But it would mean more chemicals and sediment and filth from pavement flowing right into the river untreated. The hope is that stormwater can be managed going forward. It won’t be easy but environmentalists are advocating methods for reducing impervious surfaces, particularly with new development or redevelopment.

Christine Tabak, executive director of the Merrimack River Watershed Council, which is based in Lowell, Mass., said government efforts need to be elevated. She said the response is generally considerably quicker in New Hampshire to high bacteria counts or pollution concerns, but the same can’t always be said in Massachusetts. Tabak is hoping to eventually open an office for the Council in Concord, since about 75 percent of the watershed is in the Granite State.

The river is considered a class B river, which makes it safe for swimming and fishing but not for drinking.

“It’s actually a very healthy river at the moment,” said Rachel Brown of Amoskeag Fishways.

A river’s course

The Merrimack River begins, in name, in Franklin, where two massive rivers join: the Winnipesaukee River, which begins at Lake Winnipesaukee, and the Pemigewasset, which begins in Franconia Notch just below what once was the Old Man in the Mountain. From there, the river flows south through Concord, over the Amoskeag Dam and through Manchester’s Millyard, then through Nashua, before flowing in fits and starts over Massachusetts dams in Lawrence and Lowell on its way to Plum Island, where it deposits its waters into the Atlantic Ocean. The Merrimack drains essentially all of New Hampshire’s Lakes Region, along with waterways right down through Holderness and Wolfeboro.

“Those are huge, huge watersheds,” Landry said. Along the way, the river picks up the Contoocook River, which begins along the Massachusetts border in the area of Stoddard, Jaffrey and Rindge before entering the Merrimack in Boscawen. Additionally, the Piscataquog, Souhegan and Suncook rivers, along with many smaller rivers and streams, flow into the Merrimack. Further south, the Nashua River, which begins in Massachusetts, actually flows north into Hollis and Nashua before jumping into the Merrimack. “A lot of folks don’t realize that,” Landry said. “It’s kind of a funky topography.”

In sum, the Merrimack River spans a watershed of 5,000 square miles, including Massachusetts.

The stretch of the river from Franklin to Bow is particularly pleasant. It’s common to see people swimming, fishing and paddling in warmer weather, not to mention that stretch of river generally has excellent water quality, Landry said.

A history

“I can’t even begin to believe what a difference there’s been,” Landry said, adding most rivers in the country were essentially just depositories for waste beginning with the Industrial Revolution. Rivers in New England were the catalysts for industrial might; the Merrimack sustained the entire textile industry that supported Lawrence, Haverhill, Lowell, Manchester and Nashua. The river was the power source. It was used for transportation. It was used for commerce. Timber companies floated logs down the river. It was also rather convenient for getting rid of waste. And it was the main drinking water source. (Communities have been careful to situate their own drinking water facilities upstream of their treatment plants, but upstream from one community is downstream from another.)

“It was awful,” Landry said. “In the U.S. it was a disaster. You heard stories of rivers catching fire. ... If that doesn’t tell you something is wrong with the rivers in America ….” (The Cuyahoga River in Cleveland famously caught fire in 1969.)

The situation was no different in the Merrimack River. For 150 years, the river claimed a spot among the top 10 most polluted rivers in the country. It was the Clean Water Act in the early 1970s that changed the future of rivers. No more untreated discharges. There was a boom in creating wastewater treatment facilities, Landry said.

“It was just a running gutter, bacteria, fecal matter, commercial and industrial waste,” Landry said. “That’s no more.”

Looking back, the river’s role was intertwined with society.

“[The Merrimack River] was really responsible for human inhabitation,” Eaton said.

The river’s tale truly begins after the last ice age when people began to return to the river 11,000 to 12,000 years ago. The area where Manchester now sits was an important spot for people to come and fish and also for transportation. Where the Amoskeag Dam now holds back the river was once a half-mile section that dropped more than 50 feet. As salmon migrated north, they’d get caught in rocks, which made them easy to catch, Eaton said.

“They’d catch hundreds of fish in a day,” Eaton said, adding the area became a gathering place of sorts initially for what we’d now call cave men. The banks of the Merrimack soon became populated by the Penacook band of the Abenaki, who spoke an Algonquian language. (The Manchester Historical Society has stone artifacts from the time period.) People would come from great distances, more than 100 miles in some cases, to fish in the Merrimack River. The area also became a place for spiritual ceremonies.

Some 100 years after the Boston area was settled, European settlers made their way north along the Merrimack. Scotch-Irish first settled in Derry and Londonderry. They set up grist mills and saw mills starting by at least the 1760s. They would build dams in a semi-circular fashion into a portion of the river, funneling water into their wheels. Fish could still migrate around these mills. The sea lampreys and eels, which were plentiful, remained important food and trading sources, Eaton said.

Samuel Blodgett, originally from Woburn, Mass., settled on the west side of Manchester and was enamored with the European Industrial Revolution’s use of canals, which were used for water power and transportation. He wanted to bring canals to the Merrimack. Blodgett bought land on the north end of what is now the Millyard. Others began to see the potential for canals in transportation. The river itself was often too rocky or too fast-flowing for transportation. Blodgett spent 14 years building a canal to bypass Amoskeag Falls. His first attempt failed. After hiring an engineer, Blodgett was able to open his canal in 1807. Unfortunately, Blodgett died before his canal dream could be fully appreciated. By 1814, it was possible to travel from Concord to Boston harbor and back all on canals and rivers.

The canals remained particularly important for transportation until about 1840, when trains began making their way north. Eaton said essentially wherever there were canals there would be some form of commerce. Little shops, traders and certainly manufacturing factories were situated all up and down the river in places such as Hooksett or Nashua.

“They’re something that’s really forgotten,” Eaton said. “Because we don’t see any evidence of them.”

In 1831, a group of rich Bostonians started Amoskeag Manufacturing. Having already developed Waltham, Mass., and Lowell, Mass., the businessmen essentially bought out all of the east side of the river in Manchester, developing 15,000 acres. In 1838, the first mill began operation. The men laid out the city on a grid system, the only large-scale planned city in New England.

With fishing still strong in the area, families became particularly competitive over fishing spots. They’d build platforms on their spots and there were sometimes violent confrontations if someone tried to steal a spot, Eaton said.

The company’s leaders realized there was plenty of horsepower to be had on the 54-foot drop in the river, so up went a dam. In fact, the company ended up owning all the water power rights all the way up to Lake Winnipesaukee.

The dam’s construction marked the end of fish migration on the Merrimack. It didn’t go unnoticed by residents.

“People were really upset,” Eaton said. “People ate and traded fish. It was an important food source. So it wasn’t without incident.” (Locals actually made a fish ladder to help facilitate migration but it failed.)

The dam built in 1840 lasted until it was replaced in 1920, when the power plant was built. There was a flood in 1936 that reached the second floor of mill buildings, essentially putting the Amoskeag company over the edge and into bankruptcy, Eaton said.

Today’s view

“It’s in pretty good shape most of the time,” said Landry, who has been working in New Hampshire for 18 years. “For the majority of the time in New Hampshire, the river supports its designated uses, swimming, fishing, boating and also as a drinking water source for various communities.”

Landry said things are pretty well-regulated now, though there are still some gaps and environmental officials are constantly on the hunt for illicit discharges ? wastewater discharges that are either knowingly or unknowingly hooked up to the wrong pipe, shooting untreated waste into the river. Though still troublesome, those are hardly happening on the scale discharges once were. State officials are constantly working to locate illicit discharges throughout the watershed. Sometimes it’s as simple as someone accidentally hooking the sewer line up to the wrong pipe. Once found, they’re usually fairly easy to fix, but it’s hard to know how many there are. Finding them is time-consuming, Landry said.

“People just think all storm lines go to a treatment plant, and they don’t,” Landry said. “In Manchester, that’s probably right. In Franklin and Concord, it all goes to the river.”

Volunteer monitors test for bacteria (E. coli) and aquatic insects. They look at flows and temperature and they monitor other physical factors by sight.

The standard bacteria count is 406 ? anything less is safe, anything more is deemed not safe for swimming. Landry generalized that a volunteer group sampled one area last year six times in dry conditions, and five times the count was less than 50. The sixth time the count was 88. Landry said the count was usually in the single digits, which is extremely good, considering there’s always going to be some bacteria from other animals, such as water fowl or beavers.

“In a huge river, that’s really good,” Landry said.

In the same area, following two inches of rain, the bacteria count jumped to 7,000 overnight.

“We’ve seen that pattern repeat itself,” Landry said. “If it’s dry, go out and have fun in the river. If it rained a lot, make sure the water is clear. If it’s been raining a lot, hold back a few days until you can see the bottom again.”

So the water quality is not so good during events like, say, the Mother’s Day flood of 2006.

“There may be a whole host of other disease-causing pathogens along for the ride,” Landry said of high E. coli counts. “It can be hard to measure for other pathogens.”

Similarly, in the bay area on the New Hampshire seacoast, officials shut down the clam flats after heavy rain. That’s because shellfish can absorb the bacteria from overflows.

Sewage lines carry all sorts of displeasing items through pipe systems. Taking a hypothetical peek below any of the CSO outfalls, people would see an unfortunate mix of syringes, condoms, latex gloves, sanitary products and diapers ? anything that people toss into a toilet.

“So the river accumulates that waste on the river bottom, obviously a public health concern,” Landry said. “So we’ve got that contribution that still impacts the river. That’s a big issue to consider.”

Wastewater treatment facilities were established long ago. As populations have grown and development has expanded, facilities have had difficulty keeping up. At considerable cost, facilities could simply expand, but there’s a likelihood that one day, the population would exceed that capacity as well, Landry said. Combined with a lack of capacity, the region is seeing a higher frequency of heavy rain events, which, with less and less porous surface for rain to dissipate into, means more water treatment facilities must deal with.

Treating both stormwater and wastewater is problematic for treatment facilities as there tends to be more trash and other hazards in stormwater, which can deteriorate equipment quicker. It’s hard to know how much rain would trigger an overflow. A sprinkle here or there doesn’t have much impact. But frequent and intense rain, which the region has seen plenty of in recent years ? it rained more than 20 days last June ? are likely to cause more regular overflows. The thinking is, let’s get rid of the CSOs because no one wants sewage flowing into the Merrimack, Landry said.

“This is a very, very costly and time-consuming process,” Landry said. “We’re thrilled to see CSO separation projects going on, Manchester’s West Side, a CSO on the Piscataquog. There’s been some successful separation but you’ve got to rip roads up, millions of dollars.”

The good news is that, even in the current state, if the region is being hit with heavy rain, people aren’t likely to be out swimming anyway.

It’s not just urban areas. When it rains, biologists see spikes in bacteria everywhere mainly due to stormwater.

“It all depends on the development structure within a watershed,” Landry said. If it rains hard in the White Mountains, nearby streams aren’t likely to suffer from sizable spikes in bacteria. But biologists would certainly see those spikes in Concord. “It all comes back to land use. A town like Warren up north on the Baker River that drains into the Pemi, the water quality contribution is outstanding, but in Laconia, I don’t know. You’ve got a lot of urban landscape, which probably contributes more negatively. Manchester, Nashua, Pheasant Lane Mall, those are big differences.”

“Sometimes it’s a little and sometimes it’s a lot,” Landry said. “What you’re getting is a mixture, and stormwater carries its own huge host of pollutants — whatever gets chucked down into the catch basin, trash, is also combined in a mixture of human waste.”

There are other issues along the way. The Manchester-Boston Regional Airport presents a problem. Given that, by its nature, the airport has lots of impervious surfaces, it generates a lot of stormwater. Additionally, workers use chemicals for de-icing that can be harmful in rivers. The chemicals mix right in with the rest of the stormwater, which is likely to have all sorts of other pollutants.

The airport used to discharge all its stormwater into a nearby stream, but the brook simply “couldn’t cope,” Landry said. He said it was too small to dilute all the chemicals, and fish communities suffered severely. So the decision was made to channel the discharge into the Merrimack, just off Brown Avenue, in hopes the much larger river could dilute the pollution. It’s hard to know how negatively the discharge is affecting the river. Landry said some of the chemicals could pose potential risks to wildlife — for example, antifreeze actually has a sweet taste that entices animals and pets to have a drink. Drink any measurable amount and there’s a good chance that animal is not going to make it.

Additionally, there’s always the potential for chemicals, embedded in river beds from historic pollution sources, slowly leaching from soil.

Stormwater

The focus now from an environmental perspective is on “non-point source” pollution, namely stormwater. With the river regulated so that waste of any kind can’t be deposited in the river, environmentalists are turning to impervious surfaces. Some of the preservation techniques are simple ? opting for native plants, which require less water and fertilizer.

“The big concern now is stormwater,” said Tracie Sales of the Merrimack River Watershed Council.

“Treat stormwater at the source,” Sales said.

Environmental officials push for green roofs ? putting plants on roofs with some soil to hold rainwater. When there’s a big storm, that system is going to overflow, but the green roof system would utilize stormwater from moderate rainfall instead of just siphoning it directly into the river, pollutants and all, Sales said.

Porous pavement, which is basically pavement without the smallest particles, is also drawing interest. Instead of running along roads and parking lots picking up trash, sediment and pollutants, the water simply filters into the ground, as it naturally would. Porous pavement does require more maintenance and is best served in low-use areas, Sales said. A 24-unit condominium complex in Pelham that opened recently is home to the state’s first porous asphalt road. As water seeps through the 900-foot road, pollutants are filtered out. The road also requires less salt for de-icing.

On a large scale and on a small scale, rain gardens can also be utilized. The gardens act as catch basins for stormwater and can be designed to catch water falling off a roof, driveway or road. Shopping plazas have, in some places, stopped building median dividers in parking lots “up” and have instead built them “down” in an effort to catch stormwater, Sales said.

“It’s all reducing the flow to wastewater treatment facilities,” Sales said. It’s also sustaining groundwater, which, quantity-wise, isn’t a huge issue in New Hampshire ? it is in Massachusetts in some places ? but over time it could become a bigger issue.

Fish, dams and habitat

In terms of fish, the Merrimack River can be a somewhat underrated attraction for fishermen. Healthy stocks of smallmouth bass and other species populate the river up and down. Landry does most of his fishing from Franklin down through Concord.

“Any angler is going to know you have to have good habitat to have good fish,” Landry said. And there’s plenty of good habitat from Franklin to Concord. Along with smallmouth bass, fallfish and white sucker, Landry has pulled the occasional salmon out of that region of the river.

 “The influence of dams certainly has hindered fish populations’ abilities to thrive,” Landry said.

Atlantic salmon and other migrating species are met by the Essex Dam in Lawrence and the Pawtucket Dam in Lowell. Swimming into New Hampshire waters, fish are met with the Amoskeag Dam in Manchester, the Hooksett Dam and Garvin Falls dams in Hooksett, the Eastman Falls Dam and Franklin Flood Control dams in Franklin and the Ayers Island Dam in Bristol.

Dams are essentially creating impoundments on the river. They slow the flow, creating what’s called the “lake effect” on the top side of dams. The water slows, warms up and begins to sustain a different type of habitat. From Lowell up to the Amoskeag Dam in Manchester, there’s more of a “natural run of river.” The water flows swiftly and in through Manchester there’s even some white water, with lots of rocks and boulders: “Fish love that stuff,” Landry said. Coldwater species love it because the fast-flowing water has more dissolved oxygen.

Looking at both sides of a dam, people would see two completely different types of water bodies: from a swift flowing, rocky, diversified habitat that is perfect for fish and other aquatic habitat, to upstream where water is slow-moving and deep with much less water circulation, meaning much less dissolved oxygen. It’s not that the top side of the dam habitat is necessarily harmful ? it’s great for boating and other types of recreation ? but it’s not as keen for developing sustainable and thriving fish habitat.

“The habitat isn’t as diverse,” Landry said. Not to mention, it’s difficult for anadromous fish species, such as salmon, to make their ways over and through various fish passage devices, such as fish ladders. “Where the Merrimack is allowed to have more shallow, rocky, bouldery, cobbly bottom, with woody trees down, shade and pools, the Merrimack River supports a whole heck of a fishery, if it’s allowed to. We’ve interrupted it with dams.”

And that’s where some competing interests come in. Particularly on the Merrimack, dams are still in use and providing energy. For proponents of clean energy, hydropower is a clean form of energy. Someone in favor of hydropower as a clean energy source is going to support current dams and potentially more dams. But those supporting the river’s health would want to see dams removed. Rowers would likely be displeased if slow-moving sections of the river were turned into roaring whitewater, Sales said.

It’s not just dams that have areas of competing interest. Road salt is imperative for public safety. It’s also extremely harmful to waterways. “It makes roads safe,” Sales said. “But it also kills things. Look at your lawn on the edge of a road. There’s no way for nature to break down salt.”

“The water quality is certainly there to support a larger and more diverse fishery than there is today,” Landry said.

The slower-moving, often warmer water dams and urban environments create provide sort of a catch-22 for biologists. The water isn’t as productive for cold-water species like brook trout, but it allows warmer-water species, such as small and largemouth bass, to thrive ? and anglers enjoy catching those species, said Benjamin Nugent, a biologist with the state Fish and Game Department.

In the Nashua area, for example, anglers would expect to reel in both bass species, along with black crappie and walleye. While a lot of warmer-water species aren’t native to New Hampshire, they are considered “naturalized” now. Warmer water species are found throughout the river, particularly in slower-moving sections, Nugent said.

Other fish species are dependent on aquatic vegetation, such as the bridle shiner or swamp darter. Aquatic herbicide use or water fluctuations can impact the vegetation, which is where these species lay their eggs. Sedimentation, which is the buildup of sediments such as sand from a parking lot, can impact fish species as well, Nugent said.

Anadromous fish, such as Atlantic salmon, have developed so they are born in freshwater and travel to the ocean, where they spend most of their lives. The fish then return to freshwater to spawn. Salmon, shad, river herring and sea lamprey all attempt to travel up the Merrimack River to do so. American eels do the opposite; they grow and mature in freshwater and return to the ocean to spawn. This past year 78 salmon were collected at the Essex Dam in Lawrence. The few wild salmon trying to get upstream are taken to hatcheries to maximize spawning potential.

“The long-term goal is that we would stop having to have hatcheries,” said John Warner, fisheries biologist with New England Fish and Wildlife. “The reality is, that’s currently not realistic right now.”

To help ensure fish reach spawning habitats, officials from the state Fish and Game Dept. and the U.S. Fish and Wildlife Services collect American shad and herring at dams and transport them by truck to upstream habitats, Nugent said.

For almost 170 years salmon, shad, herring, lamprey and eels haven’t been able to get to their spawning grounds.

The fish ladder at the Amoskeag Dam is geared toward helping American shad and river herring get over the dam and onward to their spawning grounds. Sea lamprey and American eels also use the ladders, along with other non-migratory fish in the river, such as trout and bass. Brood stock salmon do swing by the ladder from time to time as well. (In addition to brood stock salmon, state Fish and Game stocks New Hampshire waterways, including the Merrimack, with rainbow and brown trout, which are non-native species, along with brook trout, which is a native species.) The fish ladder is empty now, but come May, its steps will fill with water and fish. Though fish numbers are lower than officials would like, witnessing the migration from inside the Fishways’ viewing room hasn’t lost its luster for viewers.

“It’s hard to get back something that you’ve already lost,” Brown said specifically regarding salmon, which would typically spend two years in the river before heading out to sea for another two years. They would then swim back upstream to spawn. In an ideal setting, Atlantic salmon, which are actually a species of trout, would return to the sea once again after spawning. Some salmon species on the west coast return to fresh water to spawn and then die.

But there are positive signs in terms of restoration.

The Souhegan River flows freely from its mouth in the Merrimack all the way to Milford. The Merrimack Village Dam, which had impeded flow since the 1700s, was removed in September 2008. It’s not cheap to remove a dam, but it can often be less costly than performing maintenance on a dam year after year, especially when the dam is not in use. Many dams today still have legitimate purposes, such as hydropower, water supply or recreation. For dams that aren’t serving any specific purpose, the state Department of Environmental Services is suggesting to owners that removal might be the best option. There are 4,800 dams throughout the state.

With the Merrimack Village Dam gone, biologists stocked salmon fry in the Souhegan River and found great numbers of young salmon during post-dam-removal sampling last August. The fish were found in areas where they hadn’t been stocked, which suggests they were moving to better habitat ? habitat they wouldn’t have reached had the dam still been there, Nugent said. The state’s wildlife action plan, which was written in 2005, provides a summary for all wildlife species of concern, including a segment on fish. Visit wildlife.state.nh.us/Wildlife/wildlife_plan.htm.

While dams and pollutants have littered the Merrimack River’s past, the river is still flowing and still filling its role in the natural world.

Outside Amoskeag Fishways, executive director Helen Dalbeck reminds visitors to look up — “You might see a bald eagle.”

“I’ve seen eagles pull out some large fish,” said Rachel Brown, of Amoskeag Fishways. Eagles will swoop in for just about any fish hanging out too close to the surface.

The river plays an important role for many animals. Lakes and ponds have frozen over and eagles tend to congregate on the river in winter months to hunt fish. Dalbeck and her staff also see otter, mink and gray and red fox ? all in an urban environment. Dalbeck explained that unless access to the river is blocked, animals will find a way to get to it.

“You get to realize this is an amazing river that flows right through the city,” Dalbeck said. “We need to look up and look out.”

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