National Solid Waste Management Association 1730 Rhode Island Avenue, N.W. Washington, DC 20036 National Tire Dealers and Retreaders Association, Inc. 1343 L Street, N.W. Washington, DC 20005 Society of the Plastics Industry, Inc. 250 Park Avenue New York, NY 10017 U.S. Brewers Association, Inc. 1750 K Street, N.W. Washington, DC 20006 ( APPENDIX F ESTIMATION TECHNIQUES An accurate estimation of the quantities of solid waste materials is fundamental to all aspects of solid waste management. Planning in collection, landfill, incineration, or resource recovery demands accurate estimates of the materials available. The techniques outlined here provide varying degrees of accuracy. The more precise the estimate must be, the more it will cost to obtain. APPENDIX F ESTIMATION TECHNIQUES SOLID WASTE SURVEY PLANS 1. Introduction The following plans are excerpts from the Logistics Management Institute Report, Measurement and Description of the DoD Solid Waste Problem, Project 8 (Interim Report) of March 1976, selected to familiarize the users of this document with four methods of accomplishing a solid waste survey: Plan A, Low Cost/Low Precision - No Measurement Study; Plan B, Low Cost/Low Precision Survey; Plan C, Medium Cost/Medium Precision Survey; and Plan D, High Cost/High Precision Survey. Plan A uses information readily available on the installation or from published sources. It requires no field measurements and a minimum of expense. Plan B encompasses Plan A as a reference base, but requires measurements of solid waste weights on each of 15 collection days and visual estimates of the composition and container load-volume percentages. It is a low-cost plan because it utilizes collection personnel to record the data. Plan C also encompasses Plan A. A sampling schedule, which identifies individual or groups of similar waste-generating facilities, is constructed and implemented by a survey team for 20 collection-day measurements. Composition is determined by hand segregation and weight measurements. C provides a higher level of waste measurement and is more expensive to conduct than Plan B. Plan D is similar to Plan C but the survey is conducted over four 20-day measurement periods with each 20-day measurement period taking place in a different quarter of the year. 2. Low Cost/Low Precision No Measurement Study (Plan A) Plan a. Time Series Analysis, Step 1. Collect recorded monthly weight, container trips, or container load volumes of the solid waste disposed in the landfill or incinerator, plus the weight of scrap materials turned into the Defense Reutilization and Marketing Officer (DRMO), for the three most recent fiscal years. Determine if the data constitute a time series; if so, determine the secular trend and develop the seasonal index. Convert all container trip data to tons using a density factor of 82 pounds per cubic yard. If the loose-cubic-yard volume has already been adjusted for percent load (i.e., container 100, 75, 50, or 25 percent filled), convert to tons using a density factor of 180 pounds per cubic yard. Use the calculated trend and seasonal index of the time series analysis to forecast the monthly and yearly total of the solid waste tonnage for the current year. Use the trend to forecast the yearly totals for the next four fiscal years. Record, by month, the total weight and type of solid waste recovered through sales by the DRMO or volunteer efforts. b. Emission Variable Analysis (1) Step 2. Itemize the major solid waste generating facilities (or groups of facilities) and collect population, square footage, and 3. other pertinent emission variable data. Construct similar tables for each year of interest. For future years the estimates of the variables are restricted to the major categories of Family Housing, Troop Support, Industrial Activities, and Total Installation. (2) Step 3. Using the average emission factor values of Table F-1 and the models of Table F-2, calculate estimates of the solid waste generated. (3) Step 4. Compare the total solid waste weights calculated in Steps 1 and 3. If there is wide variation between the estimated weights for the most recent year of recorded data, adjust the emission factor estimates of Step 3 to close agreement with the weights determined by Step 1. The Step 1 weight is based upon volume measurements of the particular installation, while the emission factor estimates were derived from composite measurements of other installations. Once adjusted, the Step 3 estimates, which reflect the installation's activity levels, shall be used to forecast the solid waste of future years. (4) Step 5. The weights derived through Step 4 can be converted to component values by multiplying the estimated installation weights by the pertinent composition percentages of Table F-3. Low Cost/Low Precision Survey (Plan B) Plan B consists of the "no measurement" study of Plan A combined with a limited (15-day) waste source survey. Approximately 90 percent of the staffing will be composed of supervisory personnel (GS-11 or equivalent). The 15 days of weight measurements will provide a quarterly estimate of the mean weight with a precision close to plus or minus 10 percent of the mean, with a confidence level of 0.8. It will not be possible to provide a confidence level of the composition estimates as they rely on visual approximations. a. No-Measurement Analysis, Step 1. Complete the five-step analysis of Plan A. The estimates of the aggregate solid waste weight and component weights will be used as a reference base to afford comparisons with the measurement (weighed) values. b. Limited Solid Waste Survey (1) Step 2. The survey supervisor develops a system for identifying the collection vehicles and the solid waste generating sources (by building or groups of similar buildings). The survey supervisor, after consulation with collection personnel, constructs a collection and weighing schedule for each day of the two-week survey. Since the collection personnel will do all of the data recording, only minor modifications shall be made to the existing collection schedule. A protocol, covering the various steps of the solid waste survey, is constructed by the survey supervisor and explained to the collection personnel, along with instructions on filling out a collection card and weigh card. |