Putting Waste in Its Place

Standards Address Materials, Treatment, and Remediation
Adele Bassett

Lacking the high profile appeal of bridges, highways, and mass transit — and beset by perennial NIMBY (not-in-my-backyard) issues — waste management has always seemed like the stepchild of infrastructure projects. But despite an out-of-sight, out-of-mind context (unless it’s not working properly), waste and waste management are critical parts of public infrastructure, contributing to health and safety. These topics have also long been a focus for a number of ASTM International committees.

Waste from the Big Apple

New York City’s waste management history illustrates the evolution of how waste has been regarded by the general public and the persistent problem of where to put it. In the 1600s, when the city was still known as New Amsterdam, rubbish, dead animals, and ashes were simply tossed into the streets. For most of the city’s subsequent history — until the opening of Staten Island’s Fresh Kills landfill in 1947 — waste was dumped into the ocean. When Fresh Kills closed in 2001, the approximately 13 Tg of waste generated annually required new repositories. Today, according to Todd Kuznitz, deputy director of solid waste management for New York City’s Department of Sanitation, 16.2 percent of the city’s total waste is recycled or reused.  Some 73.2 percent of the non-recyclable mixed solid waste travels to landfills and the remaining 26.8 percent is burned in energy-producing plants in New York, New Jersey and Pennsylvania.

Managing Waste

“There isn’t a single way to handle waste,” explains Teresa Clark, vice chairman of the ASTM committee on waste management (D34) and vice president of development for Enso Plastics in Mesa, Arizona. Since the committee’s founding in 1980, its standards have dealt with analyzing the components of solid waste. “That’s still important,” says Clark, “but we’re now focusing more on how waste is handled, and if we handle it in the most appropriate way to prevent unforeseen consequences.”

There are six methods for managing waste: to reduce, or produce less of it; to reuse it; to recycle it; to let it biodegrade; to compost it using micro-organisms either aerobically (with oxygen) or anaerobically (without oxygen); or to put it in a landfill, where it will eventually break down.

To ensure that marketers’ terms are accurate, the U.S. Federal Trade Commission Green Guides provide further definition of green or eco-friendly waste. Products that can be “collected, separated, or otherwise recovered from the waste stream … for reuse or use in manufacturing or assembling another item” are considered recyclables. Biodegradable products eventually decompose into elements found in nature, disintegrating or disappearing. Compostable products must be scientifically proven to break down into humus (usable compost), carbon dioxide, and water in a safe and timely manner without releasing toxins and unacceptable levels of metals into the soil.

Landfills, on the other hand, are designed to store, compact, and bury waste that cannot be reused, recycled, or composted. In a dry, leak-proof, airless anaerobic landfill, gas is created by bacterial decomposition, volatilization (where wastes change from a liquid or solid into a vapor), and chemical reactions. Landfill gas is a mixture of hundreds of different gases but typically contains anywhere from 45 to 60 percent methane; 40 to 60 percent carbon dioxide, and much smaller amounts of other gases depending on the age of the landfill. This energy-rich gas is a renewable source that can be used to offset fossil fuel.

Standards for Waste Management

“We’re looking at waste management from a science and data perspective to erase the notion that there’s only one appropriate way to handle waste,” says Clark. To that end, her committee is developing guidelines for creating a product-specific waste hierarchy (WK55328) and writing almost 20 additional standards that will reflect current methods for treating, reusing, and recovering waste.

For example, the guide for operating an anaerobic digestion facility (WK56175) shows composting facility designers how to measure degradation within digesters, so they’ll achieve maximum performance and safety while minimizing environmental impact. Another standard under development defines different types of landfills based on design, operation, and environmental impact (WK55330).

The proposed classification for degradable materials and products (WK56175) will classify waste products based on how they degrade. It’s for individuals who buy, sell, and use degradable materials and products. And the draft practice for estimating the environmental persistence of materials using first order rate constant calculations (WK56177) will provide a standard for calculating how long a product will remain intact in a certain environment.

Two other standards under development — guides for materials intended for discard into municipal waste water treatment facilities (WK57010) and for materials intended for discard into municipal landfills (WK57011) — encourage companies to choose more environmentally friendly materials for producing their products and guide municipalities on what types of waste products are appropriate for their landfill systems. 

Breaking Down Plastic

One of the most pervasive and persistent waste products is the focus of a subcommittee on environmentally degradable plastics and biobased products (D20.96).

It’s estimated that 270 Tg of plastic is produced annually throughout the world. Only 10 percent is recycled. About 6.3 Tg are tossed into the ocean every year. The famed Great Pacific garbage patch is said to be the largest dump in the world, with an estimated six times more plastic than plankton in that ocean. In the United States, nearly 90 percent of all plastics is buried in landfills. According to the type of plastic used, some plastic bottles take as long as 450 to 1,000 years to biodegrade.

“In the 1990s, companies claimed to be producing plastics that would biodegrade because they were putting starch in their recipe that would make the plastic break down into a fine dust. But it wouldn’t actually fully biodegrade,” explains Kelvin Okamoto, D20.96 subcommittee chair and president of Indianapolis, Indiana-based Green Bottom Line, a consulting company. “So, it was important to develop tests to see how plastics biodegrade and agree on what was acceptable biodegradation.”

Depending on their type, plastics can be composted, anaerobically digested, biodegrade in landfills, or undergo soil and/or marine biodegradation. According to Okamoto, one standard that set the groundwork for industrial plastic composting is the test method of determining aerobic biodegradation of plastic materials under controlled composting conditions, incorporating thermophilic temperatures (D5338). “It basically says how to test to determine how fast the plastic biodegrades, and how much of it biodegrades,” he says.

Another standard, the specification for labeling of plastics designed to be aerobically composted in municipal or industrial facilities (D6400), specifies what is required for single-layer plastic materials to be considered industrially compostable. This includes some types of drinking or soda cups, with a straw and lid made out of the same material, according to Okamoto.

A third standard is a specification for labeling items that incorporate plastics and polymers with paper and other substrates designed to be aerobically composted (D6868). D6868 defines industrial compostable materials that are multi-layered; for example, a coffee cup with a compostable plastic liner.

(Look for an article with more on standards and the biobased economy in the September/October issue of SN.)

Containing Waste

Many of the standards developed by the committee on geosynthetics (D35) ensure that confined wastes don’t leak or leach into soil or ground water. Geomembranes — impermeable materials made from synthetic polymers — are used as liners to contain gas or liquid in rigorously engineered landfills.

“The standards we’ve developed provide a regimented way to measure and manage the properties and performance of geosynthetics specific to waste containment,” says Sam Allen, vice president, TRI/Environmental Inc., in Austin, Texas. Durability features include chemical resistance, resistance to UV (ultraviolet radiation) exposure, and interface friction properties contributing to slope stability.

The committee also employs predictive science, via accelerated testing procedures, to determine how a geomembrane may perform over the design life of the application. That’s especially important for landfills, whose contents may require a very long time to degrade.

Additionally, the committee has developed standards for locating leaks in buried and exposed geomembranes, such as the practices for electrical methods of locating leaks in geomembranes covered with water or earthen materials (D7007).

“Not only do those standards provide a guide for finding leaks but they give us a report card on the effectiveness of geomembrane installation and overall construction,” Allen notes.

Remediating Waste Sites

When waste gets away, standards developed by the ASTM International committee on environmental assessment, risk management, and corrective action (E50) come into play. 

“Our standards basically encompass how to characterize a site that’s been environmentally impacted, the tools needed to remediate it, and how to develop a consensus-based cleanup,” says Paul Sonnenfeld, chair of the subcommittee on environmental risk management (E50.05).

Among the standards he considers critical for effective remediation of environmentally impaired public and private property are the guide for developing conceptual site models for contaminated sites (E1689) and the guide for risk-based corrective action for chemical releases (E2081). The standards describe how to develop site-specific remediation goals based on potential human contact with a hazardous substance through inhalation, ingestion, or direct contact (i.e., exposure pathways). They also specify how to protect other living organisms and their habitat, or natural resources, which could be adversely affected by environmental contaminations that have been released or have migrated from a waste management site. 

Sonnenfeld also notes that the guide for activity and use limitations, including institutional and engineering controls (E2091), is important since it describes tools to use when waste management and disposal sites are closed but contain residual chemicals of concern. They may increase the potential for exposure pathways and therefore require site monitoring.

Marty Rowland, senior project manager for environmental remediation at the New York City Department of Parks and Recreation, and an E50 committee member, has been an important contributor to the guide for the beneficial use of landfills and chemically impacted sites (E3033). It provides a way to design and construct landfills based on their post-closure use — such as a secure anchorage for installing solar and wind farms, or even a public part — and for reviewing data to see if a site is safe for its intended use.

Rowland is also advising John Rosengard and Subcommittee E50.05 on using E3033 to help develop a new guide on recognition and derecognition of environmental liability (WK57207). Rosengard, the WK57207 technical contact, is founder of ERCI, a software company in Oakland, California. The goal for the proposed standard, says Rowland, is to “reduce liabilities and create realistic statements about risks in government and Financial Accounting Standards Board documents that governments and corporations must file to justify available reserves for remediating future risks.”

Waste Standards in an Uncertain Regulatory Future

Another potentially influential standard is the public infrastructure management guide currently in draft form (WK53277 — see page 4). The proposed standard considers waste management as well as 14 other types of infrastructure, including nature. According to Rowland, the guide gives elected officials a way to grade the infrastructure under their jurisdiction and make decisions about infrastructure management and investment “transparent, accountable, and free of political favoritism.” That way, he says, “Cities can better understand how to spend trillions of dollars effectively and intelligently, with community engagement. Since most infrastructure development impacts nature, an important factor in implementing this guide is the clustering of impacts to ensure that no infrastructure type is conceived as a silo, or a thing unto itself, and that every infrastructure type is an integrated whole.”

Concurrently, a new subcommittee on geosynthetic product specifications (D35.06) will help ensure that geosynthetic products are used appropriately in their many environmental and civil applications. Allen notes that the new subcommittee could have special relevance given the strong possibility of reductions in prescriptive environmental regulations.

Teresa Clark contends, however, that regardless of federal budget and infrastructure investment decisions, the ongoing responsibility of the waste management industry is to persistently concentrate on environmental concerns and to become more proactive and collaborative in creating standardized guidelines. “We can’t have robust standards without involvement from people producing the waste,” she says. “We need a full spectrum of stakeholders to bridge the gap between those creating it and those handling it.”

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