Senate Bill 530 established a statewide 40 percent reduction goal for solid waste disposal by Missourians. This paper will discuss current and alternative methodologies for use in evaluating Missouri's waste stream and to report the diversion rate for calendar year 1998.


The Department of Natural Resources (DNR) Solid Waste Management Program (SWMP) has been tracking waste reduction data since 1990.   While the method for calculating reduction progress has been refined over time, the current tracking method uses 1990 as the base year for measurement.  The most challenging aspect of determining waste reduction is to first assess the amount of waste that is generated.

Since 1990 the department has used an accepted computational method which measures the diversion of all types of waste disposed by Missouri. Because this methodology lumps all waste together, and for lack of detailed waste stream data, department solid waste planners have been unable to identify specific waste streams which are leading or lagging in the calculation.

The current method utilizes an annual per-capital generation rate of 1.47 tons which also was established in 1990.  This amount is then multiplied by Missouri's population for any given year to render a total waste generation figure.  Census projections from the Office of Administration, Division of Budget and Planning, were used to determine the yearly generation.  While a constant generation rate is useful for establishing a baseline to calculate waste reduction rates, it is realistic to assume that generation rates fluctuate.  Also, it is important to note that the total generation number includes industrial and commercial waste disposal along with municipal solid waste (MSW).  MSW is composed primarily of waste generated in households, office buildings, restaurants and light commercial settings.  A resent study conducted by the Midwest Assistance Program (MAP) indicates that approximately 59.6 percent of the waste stream is composed of MSW.

Because of data recently obtained by the department, we are now able to calculate a widely used yardstick of MSW recycling known as the U.S. EPA Standard Recycling Rate (SRR).  In the 1999 report of the House Interim Committee on Solid waste and recycling, the legislators acknowledged Missouri's conservative methodology and suggested that other diversion calculation methods may place our diversion rate even higher.  The EPA SRR is just such a methodology, and is being widely embraced by other states.

It has long been a concern that individuals have little or no way of affecting a significant portion of the waste that is disposed of in Missouri landfills.  This portion of the waste stream includes heavy industrial wastes, construction and demolition waste and other non MSW.  As well, not knowing the percentage of MSW in the waste stream has also been a hindrance in attempting to utilize the Environmental Protection Agency's (EPA) calculation formulas for measuring recycling and composting rates of MSW.

A recently completed three-year waste composition study, conducted by the MAP and funded by the Solid Waste Management Fund, has shed light on the types of waste being disposed of by Missouri.  The study also established the percentage of MSW within the total waste stream and has categorized by weight the percentage of materials found in the MSW stream. These findings have been useful in determining a recycling rate for several components of MSW using the EPA Standard Recycling Rate.  These recycling rates in turn can assist in determining MSW generation rates.

Waste Diversion Rate - Current Methodology
Since 1990 the SWMP has determined the annual waste generation in the following manner.  Multiply the current estimated population for the state by 1.47 tons per person per year.  For calendar year 1998, the estimated waste generation was approximately 8,013,717 tons.  The total amount of waste disposed of by Missouri is estimated to be 5,872,416 tons.  The difference between the generation rate and disposal rate, 2,141,301 tons, is the amount of material that was diverted.  Dividing the diverted amount by the annual generation renders the waste reduction percentage; 2,141,301/8,013,717 = 27 percent.  In recent years the waste diversion rate has been shown to be in decline (See Table 1).  The cause of this decrease in waste diversion is thought to be due to the an increase in consumerism resulting from good economic times.  In simple terms, when more is consumed, more waste is generated.

MSW Recycling Rate Methodology
The EPA Standard methodology for determining waste reduction, recycling and generation rates uses recovery rate estimates and/or averages established by several trade organizations for each commodity. These organizations are commonly cited by publications representing the solid waste management industry.  In addition, waste disposal figures have been provided by Missouri landfill and transfer station operators and state agency staff from surrounding states.  Despite the validity of these sources, most experts agree that even the best data and calculation methodologies yield only exact representations of waste that has actually been disposed of.

Three sources, the 1999 Missouri Solid Waste Composition Study (Composition Study), the EPA Measuring Recycling: A Guide for State and Local Governments (EPA Recycling Guide) and Recycling Today: Selected Recycling Statistics (Recycling Statistics), provide key information for determining MSW waste generation and recycling rates for Missouri during calendar year 1998.  The Composition Study indicates that approximately 59.6 percent of the waste stream is composed of MSW.  Given a 1998 total disposal rate of 5,872,416 tons, approximately 3,499,960 tons was MSW.

The Composition Study also provided an itemized breakdown of the MSW components.  The Composition Study further listed each component by a percentage of weight as it related to the entire MSW waste stream.  Many of these components represent items that may be recycled.  Estimated national recycling rates for a number of materials were acquired from the Recycling Statistics.  These recycling rates were then used along with the weight percentages in the Composition Study to determine an approximate tonnage of recycled material from the MSW waste stream (See Table 2).  For example, the approximate recycled tonnage of steel cans in Missouri may be determined by the following process:

Tons MSW disposed x Percent Steel Cans in MSW = Tons Steel Cans Disposed 3,499,960 Tons x 3.1 = 108,499 Tons Steel Cans Disposed

Tons Steel Cans Disposed x Steel Can Recycling Rate = Tons Steel Cans Recycle Steel Can Disposal Rate

108,499 Tons x .58 = 149,832 Tons Steel Cans Recycled

This method of determining recycling rates was used for all materials for which national recycling rates were available and assumed Missouri as having average recycling rates.  These average rates were then plugged into the EPA Recycling Guide worksheets.  The methodologies for determining recycling rates for items banned from Missouri landfills may be found in the Appendix.

Once the total amount of recycled and composted materials are determined, an MSW recycling rate may be determined.  The EPA Recycling Guide Worksheet uses the following method to determine the recycling rate.

Total MSW Recycled X 100 = MSW
Total MSW Recycled + Total MSW Disposed Of Recycling Rate

1,898,451 X 100 = 35%
1,898,451 + 3,499,960

The MSW recycling rate is calculated at approximately 35 percent. To determine total MSW generation, the total MSW recycled is added to total MSW disposed of.   For calendar year 1998 the estimated MSW generation is approximately 5,398,411 tons.  This generation rate has been established only for MSW and does not include the fraction a solid waste falling under the construction and demolition, industrial or special wastes.


When individual citizens call to inquire about recycling, a large number ask where specific items may be recycled.  The majority of these items are those that are consumed by the general public and part of MSW. Recycling programs in turn have focused primarily on materials from the MSW waste stream such as; aluminum, plastic and glass containers, tin/steel food cans, or paper and paper products.  Again, these materials are those that are consumed by all members of the general public.

Since 1990 the waste diversion goal has been addressing the entire waste stream that is disposed of by Missouri in sanitary landfills.  Based on the 1999 MAP study, nearly 60 percent of the waste is comprised of MSW.  Using the EPA Standard Recycling Rate for MSW methodology for Missouri waste, a 35 percent recycling rate for 1998 was calculated.  Interestingly enough, the EPA's MSW recycling goal for the nation is 35 percent by 2005.

The EPA Standard Recycling Rate includes composting but does not consider waste reduction in its methodology.  This report has not considered waste reduction in its results.  However, a methodology for capturing waste diversion figures is being investigated.

It is important not to forget the remaining 40 percent of the waste stream that is not considered MSW.  While it would appear that this fraction may be causing a negative impact on the waste diversion rate, many industries have taken steps to recycle and/or reduce the amount of waste that is generated.  Unfortunately, there have been no definitive studies done in Missouri to characterize these waste streams as fully as MSW. Targeting these areas for waste reduction and recycling grants would be one method to capture important information and to positively affect increased recovery of this valuable waste stream.

When considering the two approaches to determine the amount of waste diverted one must evaluate the merits and/or drawbacks of each.  While the original methodology uses a waste generation rate that remains constant and does not take into consideration any fluctuation, it does establish an index by which waste diversion may be measured.  This methodology shows that during calendar year 1998 there was an estimated 27 percent waste diversion rate.

The MSW Recycling Rate Methodology provides for an estimate of MSW recycling only, does not assume any MSW source reduction, nor take into account any recycling or source reduction for non MSW.  This method posts a 35 percent MSW recycling rate for calendar year 1998.  It is anticipated that further investigation will likely provide an instrument to measure the source reduction not only for MSW but the other waste as well.  The Tellus Institute for one has been investigating both source reduction methodologies as well waste generation rates.


Since 1990 the department's solid waste management planners have based waste generation projections on population increases and the amount of waste an individual throws away in a year.  Using this method, in calendar year 1998, 27 percent less waste was disposed of in landfills than was in 1990. In addition to that, an estimated 35 percent of the Municipal Solid Waste (MSW) stream-wastes from home, offices and businesses - is currently being recycled.  This estimate was derived by using the EPA's standardized recycling rate methodology, the 1999 Missouri Solid Waste Composition Study and national recycling statistics for selected materials from MSW.

Measurement instruments to determine source reduction figures for these components are being sought.  Also, it is apparent that an increased emphasis in the areas of construction, demolition and the heavy industrial waste streams may be required to target components to be reduced or recycled.  Aggressively targeting these waste streams for increased reduction and recycling is critical to achieving our long-term objectives pursuant to the Missouri Solid Waste Management Law and maximizing Missouri's total waste diversion rate.

Missouri Waste Diversion Rate for 1998 Appendix