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5.0 SOURCE REDUCTION CONCEPTS Since source reduction may be a significant part of the solution to a sewer discharge compliance problem, it is important to understand the concepts of source reduction. Source reduction is defined in the federal Pollution Prevention Act of 1990 as: ...any practice which:
In source reduction, pollutants or contaminants are eliminated or reduced within the process before they enter the wastestream. Many people interchangeably use the terms source reduction, pollution prevention, and waste minimization. For an industrial process, a source reduction "opportunity" means any input of raw material, reagent, or energy; any loss or waste of that input; or any generated byproduct or waste material. A source reduction "option" means a possible means to achieve the reduction of an opportunity. The first step in a source reduction program is to identify source reduction opportunities. Then, a number of possible source reduction options to address each identified opportunity should be conceived (developed) and studied for implementation. During development of the options, source reduction literature can be examined. The literature typically explores only a few options for a given opportunity. Thus, companies should attempt to identify source reduction options that suit their own operational methods. It is generally accepted that all source reduction options can be defined, in order of priority, as procedural changes, material changes, technology changes, and recycling and reuse. 3This category of source reduction options involves changes to operating practices in a facility. The development of such changes is sometimes called the development of "Best Management Practices." Procedural change options are usually given the highest priority because they involve no capital expenditures and are often the easiest to implement. Identification of procedural change options requires a detailed study of operational steps of the process under review. Company procedures that would typically be studied for implementation of source reduction include:
Source reduction literature often limits this category of options to finding a specific less toxic substitute for a current reagent or compound. For example, aqueous cleaners are often examined as substitutes for chlorinated or organic solvents. Actually, the material change option category can include material purification and dilution4 as well as substitution. Moreover, material change options can include product material changes as well as input material changes. Product material change methods include substitution, conservation, and change in product composition. For cleaning operations, which often produce large amounts of wastes and, therefore, can offer major source reduction opportunities, there are three types of materials involved: substrate, dirt, and solvent. All three of these materials can possibly be changed in a source reduction effort. As an example, if the base material of a product can be changed from metal to plastic, the need for a surface cleaning step before a finish coating step may be eliminated. To accomplish material changes, a facility would begin by conducting a survey of all materials used in each area including operating and maintenance materials. Then, material compositions and contaminations would have to be identified. At this point, studies would be done to learn how each product is used so that possible elimination, replacement, or minimized use could be evaluated. For mercury, material change options can be difficult to identify if the effort is intended to reduce mercury concentrations in process wastewater discharges below 1.0 µg/L (ppb). The major reason for this difficulty is that contaminant concentrations in the ppb range are usually considered "trace" contaminations and information on trace contaminants of most products and reagents is not readily available. For example, Material Safety Data Sheets (MSDS) issued by suppliers of products are required by law to list a chemical constituent only if it constitutes at least 1 percent (or 10,000,000 µg/L (ppb)) of the product. In 1995, the Operations Subcommittee of the MWRA/MASCO Mercury Work Group compiled a list of hospital laboratory reagents and other products in a database called the Mercury Products Database. Approximately 5,500 chemicals were listed with actual mercury data available for about 700 products. The database is being updated in the Phase II Work Group activity. The updated database will have mercury data for more than 800 products. This category of options can involve changing the equipment used in the process operation or using another technological approach to achieve the same product or result. For example, a new, efficient washing machine may be substituted for an old, inefficient washing machine. In surface cleaning, mechanical cleaning methods may be used instead of solvent cleaning. For laboratory test equipment, a new analytical instrument may require smaller sample sizes or may reduce or eliminate the use of certain reagents. Technology change options can also include:
Although this category of options may not be considered as source reduction to the pollution prevention purist, recycle and reuse options can reduce water usage and quantities of toxic materials discharged to sewers or shipped from a facility for disposal. Recycle and reuse options can include:
Under this category, separation technologies are often used on wastewater streams to reuse the water or to remove constituents of regulatory concern for recycling to the process as material inputs. For example, formaldehyde-bearing waste streams can sometimes be distilled to recover and reuse the formaldehyde. 5.5 Option Feasibility Analyses Once several possible source reduction options have been conceived and initially explored, those holding promise of the greatest waste minimization opportunities or cost savings would be evaluated. For each selected option, the evaluation would examine technical, environmental, and economic feasibility issues. Technical feasibility analysis would attempt to decide if the option will work in the particular process application being assessed. Key considerations include product requirements, maintenance requirements, space requirements, compatibility with existing operations, and operator training and safety. Vendor consultations or pilot-scale testing may be needed to complete the analysis. If a proposed source reduction option passes the technical feasibility analysis, it is necessary to evaluate its environmental feasibility. An environmental feasibility analysis would attempt to gauge effects of the option on all aspects of environmental compliance including emissions to air and water, generation of solid waste, possible judgments or fines, and future liabilities. Once a proposed option passes the technical feasibility analysis and is found to have a favorable environmental feasibility, it is necessary to evaluate its economic feasibility. Profitability indicators such as payback period, return on investment, and net present worth can be used. The economic evaluation would usually involve both capital and operating cost estimates. Capital cost estimating data may include equipment purchase costs, site preparation costs, support material costs (such as foundations, piping and instrumentation), installation costs, engineering costs, startup and training costs, initial permit fees, and raw material inventory costs. Operating cost data would generally be calculated as incremental higher or lower costs from the current situation. Operating cost categories may include annual permit fees and reporting costs, waste disposal costs, raw material costs, utility costs, insurance costs, operating and maintenance costs, overhead costs, revenues from sale of byproducts, and revenue from increased or decreased production. The measure of payback period is frequently calculated by source reduction assessors because of its relative simplicity. An example is the payback period analysis found in Appendix B prepared for a printing facility regarding the option of installing a fixer recirculation system in its photoprocessing operation. Corporate financial officers often prefer to use the economic measures of return on investment or present net worth for making investment decisions. Additional discussion of economic analyses can be found in Section 11.0 of this Manual. In the implementation stage of a source reduction program, necessary resources would be obtained, equipment would be installed, procedural changes would be made, and performance would be evaluated. Typically, a company would pursue implementation of those options that are low in initial costs and offer a combination of benefits including reductions in material uses and environmental discharges, improvements in occupational health and safety or in energy efficiency, and an overall savings in plant operating costs. Since the idea of changing an existing process often meets with resistance from departmental supervisors and staff, the source reduction implementation stage might also involve considerable managerial effort. Successful approaches have used policy directives and delegations of authority by upper management to a source reduction team drawn from all departments of a facility. After experiencing initial successes, the source reduction team has credibility within the facility and may then go on to implement more difficult or more costly options. This means that ways to measure program effectiveness need to be in place. Waste reduction is the ultimate goal and the key factor in measuring effectiveness. In addition, employee training programs on process operations and waste management have successfully been used during implementation of source reduction programs and as a means to assure continued benefits after implementation. While such training programs should be tailored to meet specific needs at each facility, the following topics should be considered:
The operations and waste management training programs should be presented to all affected facility personnel. Ideally, newly hired personnel should be trained within thirty days of hire. All staff members should be retrained annually, at a minimum. In addition, an audit program should be developed to learn if the operations and waste management training programs are effective. Periodic unannounced inspections should take place throughout the year to detect staff compliance with the operations and waste management policies of the facility. To keep personnel up-to-date on all waste management issues, facility managers may want to develop newsletters, informational postings, publish articles, or use other appropriate means of communication with the staff. The key to a successful training program is to keep employees informed of waste management policies and to help them understand that individual actions can make a substantial difference in the overall environmental quality and impact of their workplace. The overall source reduction program cannot be a one-time effort but should become an ongoing part of the overall manufacturing process. The need for repeated source reduction assessments becomes especially important when there are:
A truly successful source reduction program, therefore, is a continuing process of assessment, implementation, measurement, and reassessment. The success of source reduction may be measured by reduced costs in production and environmental compliance including pretreatment.
242 USC 13102. 3In Massachusetts, the Toxics Use Reduction Act (MGL 21 I), enacted in 1989, classified six types of toxics use reduction options: input substitution, product reformulation, process redesign, process modernization, improved operations and maintenance, and in-process recycling and reuse. These six types of options are covered by the four broader types of source reduction options discussed in this Manual. 4Dilution is used here in reference to a process stream. Dilution of a wastewater stream to achieve a discharge limit is prohibited by federal regulations (40 CFR 403.6(d)) and MWRA regulations (360 CMR 10.025).
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