Little is dumped at "dump" anymore
Income from recyclables and compost is up; 85 percent of trash is diverted; new technology could eliminate shipping
BY MARY LANCASTER INDEPENDENT WRITER
Trash is a constant fact of life, and what is done with waste on a small island like Nantucket - with its burgeoning population and finite water source - is an important challenge.

ROB BENCHLEY/The Independent file A view from above of the Nantucket Landfill's tipping building, materials recovery facility and digester.

The answer for Nantucket is recycling all those plastic containers, empty cardboard boxes, soda cans and apple cores. Some people may feel it inconvenient to separate their trash at the landfill, and newcomers may not understand how recycling works or why it is necessary. Because we do recycle, however, the life of Nantucket's dump has been extended, the town's revenue from recycled products and compost generated from garbage is on the rise, and upcoming technology will significantly cut costs by eliminating the need to ship items and produce the power to run the operation.

In the mid-1990s, when trash was still being buried or bulldozed into piles, Nantucketers recognized that the Madaket landfill's 22-acre area was limited and soon would not meet the

island's needs. Town Meeting foresight introduced the concepts of recycling and composting before changes in environmental groundwater protection laws banned

unlined trash depositories.

In 1997 the old ways of dumping everything into the landfill were over. The Materials Recovery Facility (commonly called "the MRF") opened and was run by the private firm Waste Options under an interim contract. In 1999, construction of a composting plant was completed and Waste Options and the town entered into a 25- year waste services agreement.

In the last two years, the tonnage of trash taken to the landfill has dropped from 73,994 tons in fiscal year 2004- 2005 to 66,122 tons in FY 2006-2007, with 28,563 of recent total tons made up of recyclables.

Since 2001, when the town began receiving all the proceeds from sales of recyclables (minus shipping and handling charges, of course), its earnings have risen from $38,219 for FY02 to $126,576 for FY06/07. While some recyclables do not fetch a lot of money because of the volatility of market values, combined with the weekly costs to ship the items off island to mills and factories for processing, the price for some categories has gone up and does bring a profit, according to Waste Options President Whitney Hall.

The compost facility has, to date, diverted more than 65,000 tons of organic material from the landfill to island lawns and gardens. Sales of compost and mulch created from garbage, from which the town gains 50 percent of revenue, went from $30,000 in FY05 to $75,000 in FY06 and FY07. That increase is due in part to an improved product as well as to better promotion, resulting in rising sales to local landscapers. The product is available in bulk at the landfill as well as at Valero's garden center, through B.E. Byrne and Holdgate Partners.

The point of these methods is to prevent the dump from filling, to reuse island trash and to reduce the possibility of groundwater contamination.

"We divert 85 percent of the waste in the landfill," said Hall, noting that as of 2006 the average national recycling rate was 30 percent. "It has been highly successful."

HOW RECYCLING WORKS

The face of the MRF contains several openings for chutes leading to the vast interior floor. The first chute on the far left is for cardboard, which amounts to the highest volume of recyclable material, averaging about 1,300 tons per year. Because of the volume, Waste Options within the last year added 40 feet by 75 feet to the building just for cardboard. A baler that compresses and bundles material prepares the cardboard for transport to mills where it is remade into new cardboard containers.

There are bins for newspaper, magazine type paper and mixed paper, which is separated by type according to recycling end usage, but Hall said at this point all the paper is being composted because it is cheaper than shipping it until prices go up, when it may be shipped again.

Plastics are also separated by category, but Hall said the current recycling price for mixed plastic is good enough to bale and send it all off co-mingled. Waste Options does not intend to encourage people to toss their opaque plastic into the clear bin while this situation occurs because if the value for a particular grade of plastic rises the company wants to be able to bale it alone without the extra manpower needed to weed it out from other categories.

Tin and aluminum are baled and shipped. Cans make up the second greatest volume of recyclables, according to a FY06/07 spreadsheet. Hall explained that a ton of aluminum represents approximately 60,000 beer cans, the same number of water bottles that make up a ton of plastic.

To the right of the MRF there is a dumpster for bulky waste, such as big plastic toys, broken patio umbrellas, unusable rugs and other items that do not fit into trash bags and are non-compostable. Bulky waste also includes mattresses and upholstered furniture, which is shipped away for recycling, as are computers, televisions, appliances and air conditioners.

Next to that dumpster are two more designated for household garbage. About eight years ago residents had to switch from black to clear garbage bags because these dumpsters, as well as bags delivered by commercial haulers, are unloaded onto the tipping floor in the building adjacent to the composter. The clear bags allow tipping floor employees to examine contents to ensure that norecyclable materials are present. They remove what they can before bag contents are conveyed into the digester system.

"There is a high degree of compliance," Hall said of what people throw, and don't throw, in the garbage.

Next to the household waste dumpsters is the glass container. Glass has a low recyclable value so it is crushed at the landfill and screened to produce aggregate, a fill material that can be used for a number of construction projects and inclusion in road materials. Beginning July 1, the aggregate became available to contractors at no cost.

Dumpsters for clean wood and metal are next in line. The wood and yard brush taken to the landfill are made into compost or mulch and remain on island. The metal

is shipped away to metal recycling factories.

THE COMPOSTING PROCESS

Directly behind the MRF is a 185- foot long, 12 1/2-foot diameter steel tube called a digester. Garbage from the tipping floor is loaded by conveyor belt into the tube where it then passes through chambers, all the while being rotated and aerated at a particular moisture level. At the end of the process, the decomposed waste is screened. Any inorganic items filtered out are recycled or deposited as residual material in the landfill's lined cell. The remaining material is aerated and moistened for about three weeks before being mixed with leaf and yard waste and cured for six months. At the end of that period the compost is screened again to create the final product permitted by the Department of Environmental Protection for public use. The landfill also now produces a topsoil which is a blend of compost and sand ready to spread and seed, and this year began making mulch by grinding clean wood such as construction pallets and lumber ends. The compost is free if consumers load it into vehicles themselves, otherwise there is a charge of $35 per ton. Topsoil costs $20 per ton, but mulch is not always available. The location for pickups is available at the scale house just past the MRF.

THE LANDFILL'S LIFE SPAN

In 2003, by order of the DEP, the "old hill" was closed and capped. The towering hill, visible when entering the dump, was a haven for rats and seagulls where for many years residents tossed everything under the sun including soiled plastic diapers, glass, cans, batteries and their garbage. By the time it closed, when open dumping was no longer allowed, Waste Options had constructed its first depository cell, a two-acre area lined with an impenetrable membrane to prevent groundwater seepage. The liner consists of six layers, starting with 12 inches of clay, then a high density plastic liner, a geocomposite clay liner, a clay-filled fabric liner, another plastic liner then an additional geocomposite clay liner. Because recycling and composting were already underway, the cell was used for deposit of construction and demolition debris (called c & d), as well as baled plastic residuals left over from composting.

As of July 2006, the DEP banned the deposit of c & d in the state's landfills and Nantucket began trucking its demolition debris to off island facilities able to accept the material. As with tires, payment must be made to the facility willing to take the c & d. Hall said the biggest surprise about Nantucket's landfill was the amount of c & d that would be generated - an amount now representing about 40 percent of the island's total trash. The c & d also makes up the largest portion of trash shipping costs, averaging $2 million a year; Waste Options pays the upfront shipping costs and is later reimbursed by the town. Even with removing the c & d from the lined cell it is reaching capacity with baled plastic residuals, and a second cell is underway and expected to be completed by the end of the year. The second cell will be used exclusively for the residuals.

Hall explained that the life span of the island's landfill is dependent on the lined cells because of a state law change that disallows burying trash in unlined locations. The second cell will probably last eight years before reaching capacity, but within that time the way trash is handled at the landfill is expected to change dramatically.

WHAT THE FUTURE HOLDS

Next month Hall will present a proposal to the selectmen on implementing gasification as a means to significantly reduce shipping costs for non-recyclable, non-compostable landfill items and as a byproduct, produce more than enough electricity to power landfill operations. Calling gasification "the technology of the future," Hall explained in simple terms that the process involves the disintegration of materials through indirect heat within a sealed container. Unlike incineration, which uses a flame source and produces toxic air emissions, gasification is non-polluting. During the breakdown process a gas forms which is similar to natural gas and can be burned to generate power.

Though recycling, composting and metal shipments will continue at the landfill, gasification will allow disposal and disintegration of all the c & d, clean wood, brush, mattresses, furniture and residuals in the lined cell, as well as those found during the ongoing mining of the old hill - an activity that stops in the summer because of the smell.

"The volume of construction waste is more than was expected and that's the reason we are looking at other technologies to be able to recycle that waste stream the same as we do the municipal

solid waste," Hall said. I