Why using surveys to calculate recycling rates is falling out of fashion.
In considering the matter of measuring recycling, most agree the numbers are rather fuzzy. As Chaz Miller noted in his “It Looked Good on Paper” column last month, “Even our ability to estimate recycling rates is limited.” A look at existing guidance and practice on how recycling rates are measured suggests that no one really follows a standard, and the metrics used to assess recycling rates vary.
Part of the reason for this is that different groups use this data in different ways. Agencies like the U.S.
In this month’s column, I look at how surveys are used to assess recycling rates. I’ll follow up next month with a look at measuring recycling based on set-out rates and mass collected.
One of the primary forms of guidance is a document developed by EPA back in 1997 for state and local governments that provides a methodology to follow for assessing recycling rates. EPA’s method is based on conducting surveys of a number of specific groups: recyclable and municipal solid waste (MSW) haulers, MRF/landfill owners, transfer station operators and end users of recyclable materials. The idea behind this survey approach and its target audiences is that this allows the total amount of recyclables and MSW to be aggregated. Then a recycling rate can be computed by dividing the total MSW recycled by the total MSW generated based on data obtained from surveys of the above groups. In theory this does allow for the computation of a recycling rate, albeit a rather generic one that, unfortunately, has a strong disconnect with the operations side of the recycling business.
There are a number of reasons for this disconnect, and one of the key ones is that the underlying motivation for EPA or a municipality is that of simply tracking how much recycling is going on. While it’s nice to know, the approach is passive and is based largely on an assumption that a MRF or landfill receives its waste from one or only a few municipalities.
However, more and more we see situations where a single MRF or landfill accepts recyclables or MSW from multiple municipalities. This is an effect of privatization and the development of regional solid waste authorities that manage waste across municipal boundaries. As a result, a survey-based approach relies heavily on the assumption that the above groups A) have the data separated in a way that allows this level of tracking, and B) have the time or desire to compile this data in an accurate manner. One of the primary limitations of survey-based data is that it can be highly subjective and uncertain, especially when the recipient is less motivated to complete the survey.
Additionally, because a broad-based survey provides a single recycling rate across a particular geographical area over a set time period, the data cannot be used effectively to ascertain a rate in specific locales within this geographical area, or over shorter time periods. While this may not be an issue in a city with a population of less than 5,000, areas with larger populations lose the utility of using a recycling rate as a decision-making tool since one rate may apply to hundreds of thousands of people or more. Nor does the method provide an effective means to measure how incentive programs impact the recycling rate.
One of the biggest disconnects with this approach is that it does not allow data to be scrutinized based on variables that likely affect recycling rates, such as population demographics, housing type or how a recycling program is structured. The data obtained is a simple, city, county or state-wide rate that is difficult to break down into a granular form, which limits its utility for recycling companies who are all about maximizing participation and the volume of recyclables given the impact of those two metrics on the bottom line.
As a result, I believe an overly broad survey-based methodology should go the way of the dinosaur. Greater utility is achieved by getting more specific information, even if such information is collected in a relatively rudimentary fashion. More on this next month.