CHAPTER 4, U.S. EPA Facility Pollution Prevention Guide, EPA/600/R-92/088 MEASURING POLLUTION PREVENTION PROGRESS You will want to measure your progress against your goals. By reviewing the program's successes and failures, managers at all levels can assess the degree to which pollution prevention goals at the facility and production unit levels are being met and what the economic results have been. The comparison identifies pollution prevention techniques that work well and those that do not. This information will help guide future pollution prevention assessment and implementation cycles. Quantitative evaluation also enables you to compare your unit with similar units in your company and with data from other companies. You will need this knowledge to plan enhancements of your current pollution prevention program, to select technologies for transfer from other operations, and to help identify new pollution prevention options. ACQUIRING DATA You will need to select a quantity (e.g., waste volume or toxicity), measure that quantity, and normalize the data as necessary to correct for factors not related to the pollution prevention method being reviewed. Although the process is simple in theory, complexities arise in practice. There are a number of factors to consider when defining what data you will track. First, the quantity selected to track performance must accurately reflect the waste(s) of interest. Second, the quantity must be measurable with the resources available to you. As in the Detailed Assessment Phase, material and energy balances will be helpful in organizing data and can help fill in some gaps in data. After deciding what data should be tracked, you will need to determine how to collect it and what normalization may be required for each category of data. Useful normalization factors include:  units produced  hours of labor  hours of production Regulatory Reporting Data Depending on the type of business your company engages in, you may have a considerable volume of data already collected for regulated waste streams. However, there can be gaps and discrep- ancies in this data. For example, RCRA wastes are characterized by waste type and total amount, but not by individual components. Therefore, this data may not be specific enough for your evalua- tion. In addition, accurate measuring devices may not be avail- able for all waste streams (e.g., vaporous or fugitive emis- sions). In such cases, your regulatory compliance reports would have been based on estimates; comparing estimates from one period to another will not yield very reliable percent-of-change figures. Finally, year-to-year comparisons may not be meaningful if the reporting requirements changed sufficiently to cause differences in how waste quantities were measured. It may be necessary to supplement regulatory data. Wastes Shifted to Other Media The pollution prevention option may eliminate part of the target material but shift some of it to another plant stream, to another environmental medium, or into the product. It can be difficult to track the shift of a pollutant from one medium to another or to determine what new pollutants may be created by the new procedure. Transferring a given pollutant to another medium or replacing it with a different pollutant is, in principle, to be avoided. If you were to find that transfer was occurring, you would need to evaluate very carefully the relative impact on the environment. Watch for shifts of wastes to other media. Measuring Toxicity The toxicity of the waste should be looked at, not just the quantity produced. Reducing the sheer volume of a given waste product while increasing its per-unit toxicity is a treatment option, but it is not pollution prevention. For example, adding lime to a waste stream to precipitate metals reduces the volume of waste but does not prevent pollution since the total quantity of metal is not changed. Since toxicity frequently is not measured as part of production reporting, you may have to establish procedures for doing so. Toxicity measures need to be developed. Normalizing for External Factors Changes in quantity are straightforward, easily understood, and relatively easy to calculate if data are available. Quantity comparisons from one period to the next can be useful input to a pollution prevention program review. However, the data will have to be normalized if there were major factors unrelated to pollu- tion prevention efforts that influenced the quantities produced. There are a number of external factors that can cause the quantities and/or mix of products and by-products to change. You will need to look carefully to see whether there are external factors for which you will need to normalize your data. Common ones to consider are: total hours the process operated; total em- ployee hours; area, weight, or volume of product produced; number of batches processed; area, weight, or volume of raw material purchased; and profit from product. For continuous processes, the product output or raw material input can be a good normalization factor. Flow processes may be measured by volume or weight, whereas plating or film-making may be better normal- ized by area. In batch processes, production volume usually is related to waste production, but it may not be a linear relationship in all cases. For example, the quantity of solvent used at a printing plant is primarily a function of the total volume of stock printed and ink used, but it is also significantly influenced by the number of color changes made. Another difficulty in comparing production and waste quanti- ties arises when the relationship is inverse. This situation occurs frequently when the production rate decreases to the point that age-dated input materials in the inventory expire. For some production processes, waste is generated during start-up and shut-down of equipment. The volume of waste created in both situations is inversely proportional to the production volume. Revenue and profit factors can indicate the amount of activity but may not be reliable indicators if market forces often cause prices to change. Thus, monetary factors typically apply only to products in stable markets. It may be necessary to normalize quantity comparisons to adjust for external factors. The...system monitors rates of toxic use and waste genera- tion...avoiding distortion of production performance due to changes in overall volume of production. From an interview with Bill Schwalm on Polaroid's program, as reported in Environmental Business Journal, December, 1991. Establishing a Baseline When a pollution prevention option involves incremental changes to a well-defined process, it is possible to derive a baseline from historical performance. However, directly applica- ble historical data would not be available for new facilities. Establishing a baseline is further complicated by changes to existing processes or equipment and by new facilities that are radically different from older plants for reasons other than pollution prevention alone. In this case, the measure of success may be the amount of pollution that was never generated. Thus, a projected amount of pollution may serve as a baseline. Historical data may not be sufficient to establish baselines. METHODS OF ANALYZING THE DATA As the above discussion indicates, measuring pollution preven- tion progress is complex. Therefore, using a single measure to summarize pollution prevention will be applicable only in the simplest cases, if at all. The characteristics of several approaches and their advantages and disadvantages are outlined in the following paragraphs. Select the method or combination of methods that best fits your data availability, facility characteristics, and corporate goals. Select the most useful analysis method(s) for your situation. Semi-Quantitative Process Description The semi-quantitative process description measurement method relies primarily on text, supplemented by a limited amount of numerical data. This type of analysis is less costly to prepare in terms of staff time and avoids many of the data collection problems discussed above. However, lack of quantitative data means that it has negligible value in evaluating achievement of specific goals. Lack of quantitative data also makes it difficult to compare similar processes when looking at potential technology transfer. Semi-quantitative methods are easier to prepare but have less utility. Quantity of Waste Shipped off Site or Treated on Site Data for analysis based on transfers should be easy to obtain. Collecting such data for the SARA Title III chemicals is among the reporting requirements of the Pollution Prevention Act of 1990. Quantities of hazardous waste shipped off site are likely to be accurately recorded in manifests, although some inaccuracy may be introduced when partial barrels are shipped. In addition, the compositions of RCRA wastes may not be available in exact percentages. The amounts of trash and other nonhazardous wastes can be estimated based on shipment costs. The amount of waste going to on-site waste treatment plants may be more difficult to obtain, but it should be possible to measure or estimate these quantities. Shipping manifests and compliance reports provide data on quantities transferred. Quantity of Materials Received Changes in the quantities of materials brought on site, as determined from receiving records, can be used to measure pollu- tion prevention progress. Most facilities keep detailed, accurate records of material received from suppliers. These records provide a source of data to track changes in the types and volumes of materials brought into the facility. However, this method may be difficult to apply at the process or project level. In addition, the quantity input will not accurately reflect the amount of waste if some of the material is destroyed during the process or is acquired from other production units in the facility, Quantity purchased is an imprecise measure because it does not account for loss during processing. Quantity of Waste Generated or Used This method is a combination of the two previous ones. It essentially gives an overall material balance for each waste component. It involves tracking the quantities of hazardous, toxic, and other materials flowing into and out of the facility. It uses data on the quantities of material purchased, produced and destroyed in the production process, and incorporated in products and by-products, as well as discharges to waste treat- ment and disposal. This approach gives an overall picture of material use but re- quires extensive data collection. Data on fugitive emissions are particularly difficult to track but can sometimes be estimated by calculating material balances. Looking at both inputs and outputs provides a more complete under-standing of progress. Analysis of a Process Pollution prevention can be measured on a process-by-process basis by examining the production process in detail for changes due to pollution prevention activities. If the process is carefully selected and can be defined precisely, this approach yields an accurate description of process-related waste. It also allows better definition of a representative production or activity index for the waste generation. However, it can be difficult to select which process to focus on in large facilities with complex, interconnected process units. The approach requires extensive data collection and analysis. In addition, many wastes may not be generated by a specific process. These nonprocess-specific wastes can be missed in a strictly process-based pollution prevention measurement system. Some types of waste that can be missed include construction debris, area lighting and utility support, and plant wastewater. Analyses based strictly on processes will overlook facility-level waste, such as lighting and construction debris. Analysis of a Pollution Prevention Project This method focuses on measuring the results of each pollution prevention activity. It is suitable for facilities that produce many products from the same production line or for facilities that have a wide variety of production processes. As with the process approach, the data requirements are extensive. It also assumes a process orientation and thus is more applicable to product or equipment changes than to behavioral changes, such as good housekeeping or improved training. Project analysis is more useful for production changes than for behavioral changes. Change in Amount of Toxic Constituents Pollution prevention can be measured by the change in the total amounts of toxic materials released. The data can be drawn in directly from SARA Title 313 Form R reporting. This method, obviously, does not apply to nonhazardous wastes. Change in Material Toxicity Testing for and eliminating the discharge of pollutants responsible for aquatic toxicity is required under the Clean Water Act. Pollutants causing aquatic toxicity may not be the pollutants on a "toxic pollutants list." The first class are compounds that are toxic to aquatic organisms and hence are assumed to be toxic to the aquatic environment. The second class are pollutants that have been tested on humans or other higher life forms and have been demonstrated to have detrimental effects. Whole effluent toxicity testing is required under the NPDES permitting process. Standard methods are available to measure toxicity to aquatic life forms. The source of the toxicity can be identified by more detailed testing. Process streams contributing to the plant waste effluents are sampled and, if needed, partitioned into separate phases. This detailed toxicity testing allows identification and tracking of the actual toxicity of wastes from the plant. Toxicity testing requires sophisticated testing and data handling, however, and may not be feasible for all applications. MEASURING ECONOMIC RESULTS Aside from assessing its effectiveness in preventing pollution, a project should be evaluated like any other new process or capital investment. Preliminary cost estimates for installing and operating the system will be made prior to installing the system. More detailed data can be collected during construction and operation. The value of reduced waste production is estimated based on volumes of waste and cost of waste treatment and disposal. The economics of the process can then be evaluated by any of several techniques such as payback period, net present value, or return on investment. Evaluate the cost effectiveness of the program.