A Tour of the Southbridge Landfill

As part of its 200th anniversary celebration this year, the Town of Southbridge is hosting a number of Walktober events.  Late this morning I joined a crowd at the Southbridge Landfill (of all places) on Barefoot Road where one of these events, an Open House, had been in swing since 10 am.  I came for a tour of the facilities which got underway shortly after I arrived.  About eight of us jumped into a shuttle bus hired for the occasion, and off we rode with Site Manager Tracy Markham, a thirteen year veteran of the department, as our guide.

Opened in the early 1980s, the 52-acre landfill, the state’s largest active landfill, is owned by the Town and is currently operated by Casella, a firm specializing in municipal solid waste management.  In the early years, the landfill only accepted construction debris, but today is it a full-service operation using modern techniques of waste disposal and adhering to rigid environmental standards.  The landfill is permitted for a maximum of 2000 tons of waste per day; the trucks bringing in the garbage are carefully weighed at the scale house, so that the tonnage accepted at the site is recorded and monitored.

From the bus, we watched the 60-ton cat compactor, which works continuously, its 10-inch spikes crushing the garbage delivered by as many as sixty vehicles per day.  Here’s one now:

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In the  background you can see the million dollar compactor (the photo doesn’t do it justice):

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The landfill uses the double-liner methodology.  Made of HDPE, this material is laid down in 20-foot wide strips and heat-fused together (a sample was passed around for us to examine).  The regulations concerning landfills have changed over the years: at first, they could be unlined, then they were supposed to be clay-lined, then the standard changed to single-layer then finally double-layer plastic, which is state-of-the-art today (notice the pipes sticking out the top).

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The maximum height of the landfill, 850 feet, is constrained by the site’s proximity to Southbridge Airport.  Other factors also play into when the landfill reaches capacity.  Insofar as this landfill has been in use for over thirty years, the Town is considering options for that scenario. Here’s part of the landfill which has been capped (I think this is what I photographed):

Southbridge-Landfill-04 The information we received from our tour guides, together with the brochure I picked up, describe a highly-designed system engineered for health, safety, and efficiency.  The land is first excavated to the layer of least permeable soil (in this case, clayey glacial till), then an underdrain system is installed, consisting of perforated pipe wrapped in a geotextile.  On top of that is the double-liner system.  The secondary liner consists of 24 inches of compacted clay, a layer of geosynthetic clay, the 60 mil plastic liner, then the geocomposite drainage layer.  The primary liner consists of the same three layers: geosynthetic clay, 60 mil plastic, geocomposite drainage.  When a site is filled to capacity, another composite liner will cap the landfill.  Even after the landfill is closed, the two processes described below, collection of leachate and the combustion of gas, will continue for decades, and will be closely monitored.

The drainage layer collects water which is then pumped out.  The water which percolates through the landfill is called leachate and is collected through perforated piping.  It is pumped into these blue storage tanks; the little one has a 72,000 gallon capacity and the big one can hold 500,000 gallons of liquid.  From here, this wastewater goes to a wastewater treatment plant where it is processed.  These tanks here in Southbridge are kept at 50% full for safety reasons, mainly having to do with the capacity of the treatment plant to accept the leachate (and not because it’s inherently dangerous to store the liquid here).

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At this point in the tour, we disembarked to visit the landfill gas-to-energy conversion plant, which was also fascinating.  Gas collection wells, which are pipes sticking out of the landfill, collect gas generated by decomposing waste.  First the gas has to be treated to remove sulfur, then most of it is flared off (two-thirds of it, if I understood correctly), and a third is converted into electricity, which is sent to the grid (inasmuch as the power is generated from a natural process, it is considered a renewable source).  This particular generator has a 6 megawatt capacity, which is sufficient to power 2000 homes.  The black tower is where the gas is burned off.Southbridge-Landfill-06This building houses the 20-cylinder conversion engines, which are very powerful (and loud):

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Our final stop on the tour was the C&D materials recycling plant, a 47,000 square foot facility operated by Complete Material Management, LLC.  This facility accepts only construction and demolition debris, 80% of which can be recycled.  When waste is brought in, it must first be separated; often the first pass is done manually.  Other machinery can sort the material by size or by type, such as wood, metal, and “ABC” (asphalt, brick, concrete).

This is the where the dump trucks arrive:

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You can see a lot of wood in this pile.  Much of the wood can be chipped; the product is eventually shipped to Canada for processing into particleboard.

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The yellow machine in the background is the first step in the sophisticated sorting process:

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Our guide to this facility, the company’s CFO, praised their relationship with both Casella and the the Town; he also mentioned that the facility employs between 20 and 40 people, which is a benefit to a town like Southbridge, with its persistent high levels of underemployment.  One might instinctively react with dismay at the thought of working in this industry, but protecting worker health is a priority; moreover, the recycling of these materials is a critical component of sustaining environmental quality.  The construction materials recycling industry also uses sophisticated technologies as well as skilled equipment operators, which would make employment more interesting and appealing, I would think.

Hurricane of Thirty-Eight

This evening I attended a fund-raiser for the Opacum Land Trust at the Publick House in Sturbridge.  Around 6 pm, guests began arriving to enjoy drinks and hors d’oeuvres and to chat with the featured speaker.  I was pleased to see a capacity crowd — I’d say there were at least a hundred people — and by 7 we had found our tables and settled in.  I think they are used to hosting banquets here, because the wait staff seemed quite efficient in getting everyone served and then clearing for dessert.  The food was certainly decent — I chose the vegetarian option, which was quite tasty.

As we ate, Opacum Executive Director Ed Hood introduced some of the organization’s officers and summarized the land trust’s work in this area.  For those who are hearing about it for the first time, Opacum Land Trust was founded by volunteers in 2000 and protects natural and cultural resources in thirteen towns in southern Worcester Country.  As of today, the Trust has protected 1,735 acres and is currently working on projects that will increase that total.  Some of the notable conserved properties in Sturbridge are Opacum Woods, at 256 acres one of the largest of the properties and also one of the first to be protected, the 281-acre Plimpton Community Forest easement, the 141-acre Riverlands easement, and the 85-acre Heins Farm easement (when a land trust holds an easement, it does not own the land but instead agrees to monitor and protect the land — these are legal obligations that remain with the property and are recorded with the Registry of Deeds).

Now living in Corinth, Vermont, featured speaker Stephen Long has been writing about New England forests for more than twenty-five years; in fact, he was the founder and long-time editor of Northern Woodlands magazine.  In 2011, he began researching a seminal event in the modern environmental history of our region: the hurricane of 1938 which struck Long Island on September 21st around 2 pm and then traveled northward, through Connecticut, Massachusetts, and Vermont, before crossing the Canadian border into Quebec around 10 pm.  Although there are many people alive today who remember this event clearly, for a number of reasons, it remains difficult for us to understand its impact.  First, we have to remember that it came as a complete surprise.  Due to weather patterns in the Atlantic, hurricanes in New England are extremely rare (who remembers the hurricanes of 1635 or 1815?), because storms traveling north from the tropics veer around the Bermuda High toward toward the east and away from the coast.  Compounding the problem was the fact that weather forecasting as we know it did not exist back then — there were no satellites, no supercomputers, no near instantaneous communications and broadcasting capabilities.  Ships at sea could radio wind speed to shore, but on this occasion, sensing danger, ships off the Florida coast had returned to port.  The second thing we should remember is that the hurricane arrived on the heels of extensive rain, and the cleanup afterwards was largely manual.

The extent of the damage is easily told but harder to put into perspective.  Damage to the coastal areas was severe, due mostly to storm surge.  In New England, Rhode Island was hardest hit, but Long Island and the Connecticut shore suffered devastation as well.  Over 600 people died, and damage to property was estimated at $300 million; in today’s dollars, the cost would be $5 billion.  Trees were uprooted everywhere:  Mr Long reported that 2.6 billion board-feet of lumber was downed.  Picture 430,000 truckloads of logs: a convoy of these trucks would stretch from Boston to Seattle and back.  The storm came and went quickly, which is why it is sometimes called the Long Island Express.  In these five hours, five times the amount of timber cut in a year was felled by the storm.  Hurricane winds in the northern hemisphere rotate counter-clockwise around the lows, which means that to the east of the track, winds are strongest, whereas west of the track, rains are heaviest.  This particular hurricane carved out a 90-mile swath, but the pattern of destruction to the forest was a mosaic: the majority of downed trees were in tracts smaller than 5 acres, due to such factors as topography and land use history.

Coming as it did on the heels of the Great Depression, this event was a boon to employment.  Massachusetts hired 5,500 CCC (Civilian Conservation Corps) workers and 16,000 from the WPA (Works Progress Administration) in the storm’s aftermath.  Joined by Forest Service crews, these men cleared trails, rebuilt fire towers, and reconnected phone lines (forest fires were a major concern), for a total of 4,876,519 man-days of labor.  Because so many of the downed trees were on private land, the New England Timber Salvage Administration was set up; this agency contracted with farmers who had fields and ponds which could be used for preserving wood.  Massachusetts had 283 storage sites: in all, 303 million board-feet of lumber (50,500 truckloads) was salvaged, of which 98% was white pine.  The trees were cut and milled using the technology of the time, meaning chainsaws were not available.  Instead, often timber was sawn in portable mills, and squaring timber was not the norm; round-edged timber was used for making boxes.

Signs of the hurricane are still visible today.  Mr Long showed photos of “pit-mound topography” which is caused by trees being uprooted; if the tree fell to the northwest, the wind was from the southeast and this area was probably affected by the hurricane.  In the case of pasture trees (also called wolf trees), the growth pattern can be used to decipher whether that tree was a survivor of the hurricane: a damaged hardwood tree will grow in a boomerang shape, whereas a softwood tree will recover and begin growing upward again.  Mr Long also pointed out that the effects of the storm on the landscape indicated that New England forests are dynamic.  In the pre-colonial era, New England’s forests were mostly hardwoods; then the European colonists arrived and chopped most of the trees down, farmed the land, and eventually left for Ohio and the Midwest.  The trees which grew back after 1850 were mostly white pine.  After the hurricane of 1938 destroyed these white pines, hardwoods have re-sprouted: our forests are now a mixture of oak, birch, maple, hickory.

Forestry in New England has also changed in the past century and even in the past few decades.  For example, forests have doubled in volume since 1950, but these woods are mostly in private hands.  When we reflect on a historical event like the hurricane of ’38, we have the luxury of hindsight.  We can examine all aspects of the event — the economic, the sociological, the ecological — and ponder how a similar event might unfold in the future.  We have made enormous advances in forecasting and communications, so we can hope that a future hurricane will not result in as many human casualties.  We can prepare our infrastructure so that our coasts can withstand storm surges.  But I’m not sure how we can protect our forests.  Perhaps we can’t — we can only hope to understand how forests work, either naturally on their own or managed by us.