Morning sun,
warming the earth, greets workers at the local landfill. Misty wafts of fog
float above, just at the horizon, revealing the yellowish grey haze of the
natural processes taking place. The smells and scents carried by the breeze
represent daily challenges to the MSW industry. Not only can the odors be foul
and irritating, but they can also be deadly. At home we might use incense or
some plug-in air freshener, but to control odor at today’s landfill we must
implement a variety of procedures and products.
A major cause
of odors in landfills is organic matter decomposing under anaerobic conditions.
Gases form because of the small amounts of oxygen and moisture inside the
landfill. One gas, methane, is very unstable. Methane is prevalent at disposal
sites. The deadly gas is colorless and explosive. Taking organic matter out of
the wastestream reduces gas formation. The US Composting Council supports
converting organic waste to compost.
The USCC, a
nonprofit trade and professional organization, opposes yardwaste and other
organic debris going into landfills. The council promotes compost research and
education. It also sets standards and supports market expansion for compost
products.
“Composting has
become a well-accepted part of the municipal solid waste system, whether
publicly operated or privately operated,” says Matthew Cotton, a principal with
Integrated Waste Management Consulting LLC (IWMC). “An increasing amount of
landfills are now home to composting facilities.”
Cotton, also
president of the board of directors of the USCC, says many landfill operators
appreciate the benefits associated with landfill composting facilities.
According to USCC, some benefits of composting are improved soil structure,
increased infiltration and permeability, reduced erosion and runoff, and
improved cation exchange capacity. To this list Cotton adds increased landfill
diversion, saved landfill airspace, deferred landfill replacement, better
community relations, better use of recyclable resources, shared infrastructure,
and compliance with recycling goals.
There are no
reliable national figures on yard trimmings diversion. According to Cotton, 23
states ban some form of yard trimmings from landfills. Some have ambitious
recycling goals leading to advanced diversion and composting programs. “It is
difficult to say which areas of the country are more proactive in terms of
diverting organics from landfills,” Cotton says. Generated organic waste varies
from one state to another, while amounts of food scraps may vary more with
population density.
“Many states
with successful and mature yard-trimmings collection programs are looking at
developing programs to divert food scraps,” says Cotton. “The West Coast of the
US and parts of Canada seem to be leading the way in food-scraps collection and
composting, but there are standout programs in other parts of the US.”
IWMC writes
Odor Impact Minimization Plans for composting facilities. “IWMC provides
troubleshooting services to composting facilities struggling with odor
concerns,” Cotton says. “We’ve assisted in the permitting and development of
over 30 composting facilities, including some of the most interesting ones in
California.”
The composting
industry has great potential for growth. Cotton says growth drivers over the
next 10 years include statewide diversion programs, ‘zero waste’ movements, soil
improvement, erosion control, water quality, and greenhouse gas emissions
reduction. “Many benefits of composting are just being understood and
quantified,” he says.
According to
BioCycle magazine’s annual “State of Garbage” survey, there are roughly 3,800
composting facilities in the US. “Some states track compost facility
infrastructure better than others,” Cotton says. “Unlike landfills or most
traditional recycling programs, the biology of composting is constant,
regardless of scale. Organic materials can be managed in a backyard, at an
onsite installation at a university, as part of an agricultural operation, or at
a 40-acre centralized commercial facility. Also, unlike most recycling, the
whole process can be done locally, from collection and processing to
manufacturing the final product.”
Cotton’s not
aware of studies comparing US composting rates with other countries. “However,
there is a worldwide network of composters that constantly share information and
try to move the industry and the science of composting forward,” he says.
The USCC’s
annual conference is a great place to learn the fundamentals of composting. “The
best way for a municipality or a private landfill to investigate composting is
to avail themselves of the many excellent training programs and conferences that
exist across the US,” Cotton says. He recommends attending training classes and
technical sessions, networking with municipalities and private landfills, or
taking in equipment demonstrations. SWANA and state associations offer training
classes and workshops.
“I always think
that overcoming the status quo is the biggest hurdle to establishing a
composting program,” Cotton says. “To some extent, low landfill tipping fees in
some parts of the country make it difficult, but even in those cases, diverting
organic materials from landfills [leads to] significant revenues in landfill
airspace savings and deferred landfill replacement and transfer costs.”
Recently Cotton
taught at the Texas Compost Advisory Council’s Compost Camp at Texas Disposal
System’s landfill and composting facility. Cotton says he thinks the facility is
an excellent example of a privately run landfill and composting facility
coexisting and complementing one another.
Compost Equals Big Bucks
One company
taking compost to the bank is the Garick Corp. in Cleveland, OH. Garick serves
landscape, recreation, lawn, garden, and construction industries. Its commitment
to sustainability and the environment is a driving force behind its composting
efforts. Garick diverts organic and greenwaste streams, converting it into
organic mulch and soil. One of its more popular products is Paygro.
Mead Paper Co.
developed Paygro in 1972 to compost cattle manure from the Ohio Feed Lot. The
Ohio Feed Lot is one of the oldest, continuously operating, enclosed-in-vessel
composting facilities in the US. Garick acquired Paygro in September 1998. It is
now a diverse line with more than 50 products.
The Paygro
division is active in community composting. The division recently offered a free
greenwaste and woodwaste collection in the Cleveland area. According to Gary P.
Trinetti, president and chief executive officer, the community was dealing with
the aftereffects of Hurricane Ike, and Garick was glad to help. Garick has
composting and anaerobic digestion facilities and partnerships throughout North
America.
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Photo: Reef Industries
Reef Industries' Griffolyn TX-1200 helps stabilize a waste conatainment unit. |
Controlling
offsite odors at composting sites is a challenge. That challenge is met through
better design, training and understanding of composting science. “There are many
well-established best management practices which can mitigate many odors at
composting sites,” Cotton says.
Cover
It Up
Some things in
the wastestream can’t be recycled, reused or made into compost. Those items
enter the wastestream and the local landfill. Then they must be covered.
“Composting is not an ADC. It is not an alternative,” Cotton reminds.
“There are some
places where operators use feedstocks that would be better composted for
ADC.”
One type of ADC
is geotextile. Geotextiles are permeable fabrics. When used in association with
soil, geotextiles can separate, filter, reinforce, protect, or drain.
Geotextiles are usually made from polypropylene or polyester.
Houston-based
Reef Industries makes cover systems for industrial, commercial, and recreational
use. Reef prides itself on using tear- and puncture-resistant materials. “Our
covers can handle the daily grind year after year,” says Gina Quevedo, marketing
manager at Reef. “Our covers feature materials that are high strength and high
performance.”
Eric Dugger,
solid waste engineer at Neal Road Sanitation Landfill in Butte County, CA,
agrees. He says the Griffolyn TX-1200 is one of the best geotextile he’s used.
“We mostly use Reef Industries TX-1200 as a rain shield,” Dugger says. “We use
it for erosion control on the slopes at the landfill. We’ve used TX-1200 for
10-plus years.”
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Photo: Reef Industries
In this photo, sheets of TX-1200 have been ballasted with sandbags made from the same materials. Rope is used to prevent the wind from moving the sandbags. |
Dugger looked
into geotextiles when directed by the Butte County Water Board. “The Water Board
thought there were water issues at the landfill, so we looked for a
low-permeable temporary cover and we came up with some tarping products,” he
says. “Reef Industries’ TX-1200 outperformed the other products we looked
at.”
Dugger is happy
with the performance of TX-1200. It is one of the most durable covers he’s seen.
“In one area of the landfill we’ve had the TX-1200 on the slope for five years.
It still functions. We might replace it next year,” says Dugger. He says
undisturbed the cover should last at least five years.
Not only does
Dugger think the Reef Industries product is good—but also the company builds and
delivers any size sheet he wants. “Once Reef gets the purchase order, I have the
product in 30 days. If I need more,” says Dugger, “we just spec it right out. We
can sole source it, because Reef provides exactly what we need.”
Landfill
Service Corp. provides ADCs, passive solar ignited landfill gas vent flares, and
horizontal landfill gas extraction terminals. One of its products is Posi-Shell,
a spray-on daily cover. When sprayed, Posi-Shell forms a durable, nonflammable
shell. It replaces soil as a cover with a stucco-like coating. It’s a simple
mix, not only for ADC but also for odor and erosion control.
In fact, some
find Posi-Shell so good that they are using it for long-term cover. Edward G.
Gibson, solid waste engineer for Winston-Salem–Forsyth County (NC), says that
with approval from the local state agency it can be used for long-term cover.
“Posi-Shell has greatly reduced the amount of cover previously used,” says
Gibson. “Our operation is more efficient. We save precious airspace and wear and
tear on equipment.”
Gayle Wilson,
director at Orange County Solid Waste Management in Chapel Hill, NC, says the
county began using Posi-Shell in late 1996, after examining ADC products
available at that time. “Posi-Shell performed significantly better than any of
the other products,” she says, “and has been saving Orange County approximately
$2,500 daily in airspace in the years we’ve used it.” In 2006 and 2007, the
Orange County Landfill managed 86,215 tons.
Roll
It Out
Dugger is also
familiar with the Canton, OH–based Tarpomatic. “Butte County’s had the
Tarpomatic about two years,” he says. “Tarpomatic replaces a crew of three to
five workers with a single bulldozer driver. The tarping system hooks up to
dozers and has built-in weights. The county recently ordered a second
spool.”
Tarpomatic’s
automatic tarping machine (ATM) can be used with dozers, compactors, and
rubber-tire loaders. Portable controls eliminate worker contact with waste in
the landfill. Because municipal solid waste handling is labor-intensive and
dangerous, the ATM eliminates the need to walk around on top of the trash. This
is an important factor to Dugger. The Neal Road Sanitation Landfill uses CAL
FIRE (California Department of Forestry and Fire Protection) crews as labor to
put the tarps out. “These laborers are inmates, and their safety is important,”
he says.
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Photo: New Waste Concepts
A SWAT TF 1000 unit from New Waste Concepts propels mist about 200 feet |
Cost for Butte
County’s project was $84,550. But don’t let the cost take your breath away.
Tarpomatic offers a lease payment plan that can help with operating budgets. The
lease plan allows a municipality to avoid a large upfront capital investment.
Payment plans vary from two to five years and have a low fixed APR.
When
the Dust Settles…
Another way to
control odors is through dust suppression. One company, seeing opportunity,
expanded its personal comfort (pool and spa) misting systems to dust suppression
at landfills. Aero Mist Inc. dust-suppression systems are high-pressure misting
systems. The mist incorporates products designed to attract and neutralize dust
particles.
“The landfill
and waste industry is a new segment for Aero Mist,” says Scott Klein, operations
manager for the Phoenix, AZ–based Aero Mist. “Customer demand had us looking at
how we could develop our pool misting systems to help with dust suppression. We
get so many calls because of regulations mandating no dust in the air. That’s
exactly what our misters are designed to do.”
Aero Mist
high-pressure mist systems produce 10-micron water droplets to attract,
suppress, and remove dust through agglomeration. Dust particles drop from the
air without wetting the area. The system is made of stainless steel, with custom
spacing and custom nozzle size, and ensures compliance with regulations.
Currently Aero
Mist’s customers are regional, but the company looks to expand the
dust-suppression systems nationwide. “We’re a small company, so customer service
is important,” says Klein. “Our one-on-one provides the best opportunity to work
directly with the customer. Each of our systems is custom designed.” It’s really
all about the customer not understanding how it all works. The dust-suppression
system is no different than Aero Mist’s cooling misting systems. Aero Mist
designs the dust-suppression system, provides the materials, and prefabs it.
Klein says he
thinks one of the biggest challenges (for MSW industry) is awareness. “Most
landfills don’t how to deal with new and more restrictive regulations,” he says.
“That’s where our customer service—listening to needs and coming up with a
solution—works.”
Aero Mist’s
first dust-suppression system was designed for Mike Miller of Sonoran Process
Equipment Co. (SPEC). “Because of tough environmental rules, we were being
required to use water to control dust,” says Miller. “We were using hoses, like
garden hoses, to water down the area. But all that dust and water clogs the
equipment.”
The Aero Mist
creates a mist so fine it is almost like a fog. “Aero Mist provides such a high
concentration of water, we’re able to knock the dust particles down,” says
Miller. “We don't have to use as much water, the effectiveness of capturing is
great.”
Miller says he
stumbled on to Aero Mist while at a Home Depot. “Aero Mist was making a personal
comfort misting system, and we looked at it and saw it was made in Phoenix, so
we went right to the manufacturer,“ he says.
Savings on
water use is one of the benefits Miller sees. “Because it is
high-pressure/low-volume, we can cut our water use to 5 or 6 gallons of water a
minute,” says Miller.
The SPEC
project evolved when Metso Minerals acquired Svedala Industries. SPEC supplies
equipment and aftermarket service for aggregate, construction, mining, power
generation, and industrial markets. Miller says he sees how the misting systems
could work at landfills.
“The mist looks
like dust in the air,” says Miller. “Once the soil is dampened, soil, dust,
debris, and trash don’t blow around. And because of the way Aero Mist works, you
can add an odor control or neutralizing agent.”
“Our future
will grow with awareness,” says Klein. “Aero Mist dust-suppression systems will
help keep fines down.”
No
More Rotten-Egg Smell
Odors found in
landfills often result from anaerobic conditions. These conditions can create
hydrogen sulfide, mercaptans, ammonia, amines, volatile fatty acids, and other
reduced-sulfur compounds. New Waste Concepts of Perrysburg, OH, incorporates
specialized bacterial strains into its Odor Ranger Plus product. Odor Ranger
Plus, an enhanced version of New Waste’s original Odor Ranger, neutralizes
sulfides, mercaptans, and volatile fatty acids. It also controls a broad range
of compounds containing sulfur and nitrogen.
Tony Knight,
chief executive officer at New Waste Concepts, says the product can be applied
full strength or diluted, manually or via automatic fogging systems, and works
great at landfills and compost facilities. “NWC uses SWAT [“Sprays Wide And
Terminates”] to vaporize odor targets. The spray cannon fires a layer of
polymeric cover material to suppress evaporation and volatilization of odor
molecules,” says Knight. “The hydraulically driven rotary-head misting fans
disperse our product and saturate concentrated odor areas.”
Knight
continues, “Wastewater treatment plants, landfills, transfer stations, recycling
centers, and hazardous cleanup sites are some of the most heavily regulated in
the world today. Our product gives immediate odor relief,” he says. “It provides
a powerful combination of fast-acting chemical and biological neutralizers for
immediate odor relief. It allows bacteria to degrade the malodorous compounds,
enhanced by proprietary ingredients that stimulate microbial activity.”
Kevin Roy,
division manager at Casella Waste Systems Inc., says the major concern he has
with odor control is that of no tolerance for odor. “New Waste helps us by going
after the problem at the micro level,” says Roy. “Now we can go to the source
[of the odor].” Casella, located in Vermont, is a regional solid waste services
company. It provides collection, transfer, disposal, recycling, and resource
management services to residential, industrial, and commercial customers,
primarily throughout the eastern United States.
Roy says fellow
Casella employees made him aware of New Waste and its products. “With concerns
about sludges, hydrogen sulfide, and landfill gas in general, we had to find a
product to address them,” says Roy. “We’ve been using New Waste’s products for
about three years.”
Casella used
the technology to eradicate problems caused at the landfill by a previous owner.
The landfill had used ground-up gypsum board, and it wasn’t converting to
compost. “The odors were permeating the neighborhood,” Roy says. With the trend
going to zero tolerance for emission and odors, he says, it was necessary to fix
the problem at the source.
NWC is
responsive to customer needs. “The company is always introducing new products,”
says Roy. Roy says he thinks responsive development is important because of
increased regulation.
So
maybe that mist wasn’t caused by temperature inversion; maybe it was just the
misting application of an odor and dust suppressant—something that’s just
downright neighborly.