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Striving for Consistency: Standardizing Recycling Measurements

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Several years of study, experimentation and field testing by the U.S. EPA have resulted in a standardized methodology for measuring recycling rates.

by Hope Pillsbury

Variations in the way recycling rates are calculated have made "apples-to-apples" comparisons of state and local programs virtually impossible. Differences in how recycling terms are defined tend to further complicate the issue.

Recycling measurement, in fact, can vary in at least five ways: 1) How recycling is defined (some states give local governments partial credit toward achieving recycling goals for waste-to-energy); 2) What is counted in the recycling rate (some state laws put limits on what municipalities can count, while others allow them to include everything from automobile hulks to chicken droppings); 3) How municipal solid waste (MSW) is defined (some jurisdictions count biosolids or industrial wastes as MSW); 4) Whether a base year is used (some jurisdictions calculate a recycling rate based on MSW generation during a specific "base year" rather than the current year); and 5) How volume estimates are converted to tons (conversion factors can vary greatly).

After several years of study and work, the U.S. Environmental Protection Agency (EPA) has developed a voluntary, standard methodology for measuring recycling rates. To accomplish this task, EPA worked closely with the Council of State Governments and local, state and national recycling representatives, as well as the private recycling industry.

The methodology can be used in two ways: 1) States and localities can use a work sheet to "translate" their existing recycling rate to the "standard" MSW recycling rate; or 2) They can use an EPA guidance manual to implement a recycling measurement program consistent with this standard method. The manual also provides information and forms that allow states and localities to track recycling of materials not included in the standard recycling rate calculation (i.e., nonmunicipal solid waste, such as construction and demolition debris).

The work sheet can standardize recycling rates, adding and subtracting recyclables and waste from previously collected data to devise the numerator (the amount of MSW recycled) and denominator (the amount of MSW generated) of a standard recycling rate equation. It relies on standard definitions for recycling and MSW. In essence, it is a dictionary for translating recycling rates into a common language.

If states or localities count materials in their recycling rates that are outside the standard definition of MSW —such as food processing, agricultural, or construction and demolition wastes —the work sheet guides them through a process to subtract these items out of their waste generation and recycling numbers. Conversely, when a jurisdiction’s scope of materials is more narrow than EPA’s scope (e.g., some state laws only allow recycling of designated materials to count toward reaching recycling goals), these states and localities can use the work sheet to calculate a second, broader recycling rate.

The scope of materials included in the standard MSW recycling rate are described in EPA’s recycling measurement guidance manual. To be consistent with the standard recycling rate, only solid waste defined as "municipal solid waste" is included when calculating the amount of waste disposed and recycled. For recycling, only the activities that fall within the scope of recycling, as defined in the methodology, may be counted.

The manual explains recycling measurement methodology and provides a number of tools, including case studies; detailed charts of the scope of MSW and activities that constitute recycling; work sheets to translate data into the standard format and for states and local governments new to measuring; survey forms for obtaining data; planning checklists; detailed descriptions of all the elements of the methodology; and a glossary of standard terms.

Testing The Methodology

Washington State has used a formal reporting system to measure its recycling rates since 1986. Its recycling law, the "Waste Not Washington Act," requires the Washington Department of Ecology (DOE) to characterize and report on the state’s waste stream, define MSW, and specify what is counted in the state’s recycling rate. In 1996, approximately 450 haulers, facilities, municipalities, and buyback centers were surveyed by DOE to determine a recycling rate. Based on this information, the state calculated a recycling rate of 39 percent. A rate was then calculated using EPA’s methodology, and it fell to 36 percent.

The main difference in the two rates was in the metals category. Washington counts automobile hulks and some construction and demolition debris, which are not included in the EPA methodology. The other significant difference was in wood. "Washington only counts leaves and grass clippings within yard waste, so I was able to add more woody debris from residential yard waste into the EPA calculation," explains Kip Eagles, data collection manager for DOE. "Adding almost 200,000 tons of wood helped to make up for some of the loss Washington felt from subtracting over 250,000 tons of metals. None of the other categories —paper, plastics, textiles, tires, etc. —had to be altered."

In contrast, Pennsylvania’s recycling rate increased as a result of using the EPA methodology. Prior to 1996, Pennsylvania considered only materials listed in the state’s recycling law when calculating progress toward its 25 percent recycling goal (e.g., bottles, cans, office paper, newsprint, corrugated containers, plastics, yard debris and automotive batteries). For 1996, this resulted in a 19 percent recycling rate. However, by using the EPA method, DEP was able to include food residuals, textiles, and tires in its calculation, bumping the recycling rate to 26 percent.

EPA expects that states and localities may need to do some estimating when first using the translator. The need to estimate should subside in subsequent years as states and localities fine-tune their own survey forms to assist them in translating their data, such as separating MSW from non-MSW data on the forms.

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