Waste Characterization Tool Limits and Background

The Waste Characterization tool estimates waste stream data for jurisdictions in California by combining statewide average waste characterization data from CalRecycle’s 2014 studies with local employment (2015) and population (2016) data. This tool is designed to assist local jurisdictions and other users who may not have the resources to collect their own local data. There are limitations to how well the estimates from the tool reflect actual local conditions, mainly because statewide average data may not represent an individual city or business, and because some employment data is suppressed. Since the tool provides estimates only, it should be used as a planning tool, not a measurement tool. Jurisdictions and other users should carefully consider if use of this data is appropriate for their particular task. Limits are described below. More detailed background on data development follows.

Data Limitations

Waste management practices vary not only city by city, but business by business and residence by residence. Using statewide averages gives a good overall picture of what might be expected, but does not provide an exact measurement of what’s actually going on at the local level. The tool is built on the assumption that businesses of a certain type produce similar wastes at similar rates (per employee), regardless of the location or size of the business, and that residential generators are generally the same throughout the state.

Local factors such as climate and economic development may impact the waste stream, so that the average composition and production rate data may not reflect local conditions. The estimates, being based on statewide factors, may have larger inaccuracies for jurisdictions that have above or below average rates for recycling and diversion.

Business Groups

Although business groups were designed so that businesses with similar activities and waste streams were combined, some groups may contain business types with dissimilar waste streams. Even businesses of the same type may have different waste stream characteristics, because of different business practices or different functions. For example, both fast food restaurants and "sit-down" restaurants are included in the same business group, but the waste streams may differ because of their business practices.

Business size plays a role. Larger businesses tend to be more efficient and produce less waste per employee. The disposal and diversion rates for business groups reflect the average of many different-sized businesses. If a jurisdiction has mostly large businesses, or mostly small businesses, the disposal rates will differ from the average and tonnages will be either underestimated or overestimated.

Within a business group, the material types have different amounts of variability. For example, the amount of white ledger paper disposed by the "Services - Professional, Technical, & Financial" business group may be pretty consistent, but the amount of ferrous metals may be vary widely.

Employment Data

Employment data is for 2015, the most recent data available at the time of tool development. It is from California’s Employment Development Department (EDD), developed specifically by EDD for this tool. EDD must strongly protect the confidentiality of employment data, therefore some employee counts in some jurisdictions have been suppressed and are reported in the database as zero values. Employee counts are suppressed for a group when there are fewer than 3 businesses in that group in a jurisdiction, and/or when any single employer accounts for 80 percent or more of the total employment in a jurisdiction.

Also, since the database contains totals for all groups combined, if data for one group is suppressed, an additional group must also be suppressed to prevent deriving the missing data by subtraction. The second group that is suppressed is usually the group with the least employment of the remaining groups.

Most suppression occurs in smaller jurisdictions with fewer businesses, but not always. Data for the "Education" group can be suppressed if there is only one school district in a jurisdiction or if any one district accounts for 80 percent of the Education employment. For some small jurisdictions it may seem that much data is suppressed; however, overall only 4% of statewide employment is suppressed.

Residential Data

Residential data in the tool is based on 2 statewide studies done by CalRecycle in 2014. One study included multifamily residences along with businesses (Generator Study), and data was collected for disposal and diversion, which is included in the tool. Data for single-family residences was collected in a different study (Disposal Facility Study), and only data for disposal was collected. Therefore, when looking at the residential sector as a whole (single-family plus multifamily), only disposal data can be reported. The residential calculations use population and housing data for 2016, the most recent data available at the time of tool development,

Background on Data Development

Waste characterization data consists of information on the materials found in waste or discard streams. This tool contains information for types of generators, such as a business group or type of residence. For example, food waste makes up about 51 percent of the materials typically disposed by restaurants.

The web tool consists of 3 main types of data: waste composition, waste production rates, and employment data.

Data for business and multi-family waste composition and waste production rates is from CalRecycle’s 2014 Generator Study. Data for single-family residential disposal composition and disposal rates is from the 2014 Disposal Facility Study.

If we assume that similar businesses have similar waste streams, we can use waste data collected from one business, say a bank, to estimate what's in the waste stream of another bank. But since businesses vary in size and operations, it would be better (more representative) to look at several banks to develop a typical waste profile or composition for banks. This is how the waste compositions and production rates in this web tool were developed. Although we make the assumption that bank operations are similar statewide, this may not be the case. This is one of the several limitations of the data (see above).

Since there are many kinds of businesses, we took the 95 three-digit federal NAICS codes and made 16 business groups. The criteria for designing the groups were to put businesses with similar waste streams together, to focus on groups with large employment in California, and to separate out business types that generate large amounts of organics. The Not Elsewhere Classified group is a "catch all" groups of less similar businesses, but ones that are also less numerous and/or less likely to be targeted for waste diversion programs. Also, since waste from construction activities occurs at the building site rather than the construction company’s office site, construction businesses were not included.

Waste Composition

Waste composition data shows the breakdown of a waste stream, such as percent of each material type in that stream. Data on the waste streams of over 800 individual businesses (50 per business group) and 50 multifamily sites throughout the state was collected by examining waste from the disposal, recycling, and organics bins of each business. Also, any “Other Diversion” that was occurring apart from bin collection was quantified through interviews and other data collection at the business site. For composition data, samples of waste were physically sorted into 68 material types, such as food waste, newspaper, clear glass, ferrous metals, etc. The amount of each material type in each sample was weighed. Data from all the businesses sampled in a business group were combined to get the average composition for that group.

Waste Production Rates

Waste production rates in the tool for either disposal or diversion by businesses consists of the annual amount of material produced per employee, or tons per employee per year (TPEPY), using total employment, not full-time equivalents (FTE). Waste disposal rates for residences are based on tons per resident or tons per multi-family unit.
Note: TPEPY values based on FTE employment can be found in Table 27 of the 2014 Generator Study report.

For the residential sector, a statewide per resident disposal waste production rate was estimated. Combining this value with a jurisdiction's population provides an estimated total residential disposed tonnage. Multiplying a jurisdiction's number of multifamily units by the statewide per-unit disposal rate provides an estimate of the multifamily contribution to the residential disposed waste stream. Subtracting the multifamily estimate from the total residential tonnage previously obtained results in an estimate of the single family component.

Employment Data

2015 employment data for each jurisdiction is used to estimate disposal, diversion, and generation amounts for business groups in that jurisdiction. Information on the number of businesses and number of employees in each business group in each jurisdiction is from California’s Employment Development Department (EDD) and has some restrictions – see limitations above. Housing and population information for January 1, 2016 is from California’s Department of Finance (DOF).

How Data Is Combined

Estimated Business Waste Amounts for a Jurisdiction (see the “All Business Groups” selection here).
The number of employees in a business grouping is multiplied by the TPEPY for that stream for that grouping to estimate the tons from that business grouping in that city. For example, say there are 10,000 employees in the Medical & Health group in a city. The disposal rate is 0.57 tons/employee/year. Multiplying 10,000 employees by 0.57 tons/employee/year results in 5,700 tons/year.

Estimated Waste Compositions
The typical waste composition for a business grouping can be combined with the estimated waste amount specific for that business grouping in the selected jurisdiction. This results in an estimate of the tons of each material type in that particular stream for that business grouping in that jurisdiction. For example, if a city’s Medical & Health group disposes 5,700 ton per year and white ledger paper is 1.4% of all materials disposed, that means 80 tons of white ledger paper is disposed by that group in that city. Business group waste compositions are here.

Overall Business Waste Stream (see the "All Business Groups" selection here)
The tonnage amounts of a specific material type from each business grouping can be added together. This will estimate the tons of that material in a particular stream for all the business groupings combined. This can be done for all material types to estimate the overall business waste stream.


Comments, suggestions, questions? Contact CalRecycle waste characterization staff at wastechar@calrecycle.ca.gov

Solid Waste Characterization: https://www2.calrecycle.ca.gov/WasteCharacterization/
Contact: wastechar@calrecycle.ca.gov