Oregon Department of Environmental Quality Waste Prevention Strategy – Background Paper #1 Solid Waste Generation in Oregon Composition and Causes of Change Prepared by February 2007 Solid Waste Program Solid Waste Generation in Oregon: Composition and Causes of Change Prepared by David Allaway, Oregon DEQ February 6, 2007 Executive Summary Waste Generation Up 70% in 12 Years Since DEQ first began tracking recovery and disposal of solid waste in 1992, the quantity of waste generated in Oregon has grown significantly. Waste generation – both on a total as well as a per-capita basis – has grown every year since 1992. According to published DEQ statistics, total generation of solid waste (including both recovery and disposal) increased 70% between 1993 and 2005. Population growth accounts for only a portion of that increase; on a per-capita basis Oregonians sent 43% more off to be recycled, composted, or disposed in 2005 than we did 12 years earlier. This finding implies that the throughput of materials in our homes and businesses has grown rapidly, and by extension, that our consumption and use of natural resources has grown as well. Even as some industries become more efficient in their use of resources and reduce their environmental burdens per ton of material produced, such improvements may be offset by increases in both total and per-capita consumption. Purpose of this Report Oregon law calls for total waste generation to stabilize by 2009. In order for this goal to be met, assuming population continues to grow, per-capita generation will need to reverse its upward trend and begin to fall. In order to better define its role in helping the state achieve this goal, the Oregon DEQ is in the process of developing a Waste Prevention Strategy. As part of that project, DEQ has developed this report, the purpose of which is threefold: • Characterize Oregon’s waste generation, including, where possible, its components on a material- and product-specific basis. • Describe the recent changes in waste generation. Why has Oregon’s waste stream grown so rapidly, even on a per-person basis? Which materials have grown at a faster rate than others? • Where possible, explain the causes of the reported increase in waste generation. Increasing Generation of Construction/Demolition Wastes, Yard Debris, and Plastics During the period studied in detail by this report (1993 – 2002), according to data published by DEQ, the greatest increases in per-capita generation occurred in the categories of yard debris, a variety of materials associated with building practices (lumber, inerts), scrap metal, and plastics. However, some of the increases reported by DEQ did not result from increases in materials use or “wasting behaviors” but rather represent shifts in how wastes were managed or reported. Oregon Department of Environmental Quality Page 1 07-LQ-005 During the same time period, the U.S. EPA, which only traces changes in municipal wastes excluding construction and demolition debris, observed relatively little change in per-capita waste generation. DEQ’s estimates include many construction and demolition wastes; EPA’s estimates normally do not. This explains in part how DEQ finds per-capita generation to be rising while EPA finds little to no change. Interestingly, for the one year in which EPA estimated per-capita construction and demolition waste (1996), EPA’s per-capita estimate of municipal waste plus construction/demolition waste was within 10% of DEQ’s estimate of per- capita solid waste. According to EPA, during the period 1993 – 2002, per-capita generation of durable goods increased, while per-capita generation of non-durable goods was essentially flat and per-capita generation of containers and packaging waste actually fell slightly. Among specific product types, EPA found that generation of plastic packaging, clothing/footware, commercial printing, small appliances, and carpets/rugs outpaced growth in personal consumption expenditures, which historically has grown in fairly close parallel with waste generation. Causes of Increasing Waste Generation In this report, DEQ identifies and attempts to evaluate 16 different hypotheses as to why per- capita waste generation has grown. While data to evaluate some of these hypotheses is lacking, it appears that 11 – 19% of the total increase can be attributed to changes in the reporting of waste data, particularly scrap metal. These increases are not real, but rather an artifact of inconsistencies in data collection and interpretation. An additional 5 – 20% of the total increase in per-capita generation can readily be explained as waste management has shifted away from “non-counting” methods such as burning and home composting and toward “counting” methods such as centralized composting and landfilling. These shifts represent an increase in “waste generation as it is counted,” but do not represent a real increase in material use or “wasting” behavior. This estimate (5 – 20%) is probably low, due to insufficient data. The remaining growth in per-capita generation – perhaps 50% to 80% of the observed increase – appears to be caused by real increases in waste-generating activities and materials use. Oregonians are, in fact, producing greater discards per person (on average) than we were in the early 1990s. An increase in the generation of building-related wastes (construction, renovation, and demolition debris) appears to be a significant factor, and one that will continue to be of import into the future. Because most building-related waste results from renovation and demolition activities (as opposed to construction), the majority of building materials consumed don’t end up as wastes until years or decades after construction. Today’s building wastes are largely materials that were purchased and installed years or decades ago. This is a different pattern than, say, packaging or non-durable goods, which tend to become waste within days or months of purchase. At the same time, new single-family homes are become larger and even more material-intensive, portending the possibility of even higher generation of waste in the future, once these buildings eventually undergo renovation and demolition. Oregon Department of Environmental Quality Page 2 07-LQ-005 In addition to increasing waste from buildings, other likely causes of increasing waste generation in Oregon include: • increased purchases of household furnishings (associated in part with larger house sizes), • decreases in the durability and repair of so-called “durable goods,” and • other increases in consumption associated with rising incomes, falling prices, increased access to credit, more pervasive marketing, changes in social norms, and other factors. In addition, real generation of yard debris (leaves, grass, prunings) may also be up, although the cause of such increase is not immediately obvious. Evidence for some of these increases is somewhat limited, and further research into these topics may be appropriate. Oregon Department of Environmental Quality Page 3 07-LQ-005 Table of Contents 1. Introduction.................................................................................................................................7 2. Conceptual Models of Waste ......................................................................................................9 2.1 Washington’s “Beyond Waste” Model...................................................................................... 10 2.2 Conceptual Model of an Individual Household......................................................................... 14 3. Review of DEQ Data ................................................................................................................18 3.1 Overview of Data Sources and Methodologies ......................................................................... 18 3.1.1 Disposal Data....................................................................................................................18 3.1.2 Recovery Data...................................................................................................................19 3.2 Estimates and Trends of Material-Specific Waste Generation - Statewide............................... 21 3.3 Estimates and Trends of Overall Waste Generation - Wastesheds............................................ 24 3.3.1 Analysis of Demographic Variables .................................................................................27 3.3.2 Rates of Change................................................................................................................28 4. Review of EPA Data.................................................................................................................28 4.1 Overview of Data Sources and Methodologies ......................................................................... 28 4.2 Estimates and Trends of Total MSW Generation...................................................................... 30 4.3 Estimates and Trends of Broad Categories of Waste Generation.............................................. 30 4.4 Point Estimate of C&D Debris Generation from Buildings ...................................................... 32 5. Comparison of EPA and DEQ Data and Methods....................................................................33 5.1 Total Waste Generation............................................................................................................. 33 5.2 Individual Material Categories .................................................................................................