Pollution Prevention Programs

Pollution prevention is often discussed within the context of a widely accepted notion of a "waste management hierarchy." The waste management hierarchy places the highest priority on reducing waste at the source of generation through the use of less toxic raw materials, equipment changes, process redesign, and better housekeeping and materials management. The second preference in the hierarchy is reuse and recycling of wastes that cannot be reduced at the source. The third preference in the hierarchy is waste treatment, and the least preferred alternative is disposal. It is important to note here that prior to the mid-1980s, federal environmental legislation focused heavily on prescribing and regulating waste treatment and disposal (the bottom of the hierarchy).

In the mid-1980s, in response to rising concern over the costs of environmental compliance, some companies began seeking ways to reduce the amount of waste generated by manufacturing operations without completely abandoning and redesigning existing production processes. Many companies have implemented pollution prevention programs over the past 10 years and have significantly reduced the costs of waste disposal and environmental compliance. There are numerous success stories of firms with successful pollution prevention programs that have found it cheaper and more publicly acceptable to sell products under a pollution prevention banner. The following are from Preventing Pollution in the Chemical Industry [5].

Amoco's facility in Natchez, MS no longer uses xylene as process solvent. A team composed of process engineers, researchers, and operations personnel successfully found a way to replace xylene with an aliphatic solvent. The resulting product quality met all analytical specifications, the new process met all plant requirements, and the product exhibited improved aesthetics and incorporated raw materials more efficiently, thus increasing product yield. By making this change in the process, the plant realized direct solvent savings, decreased energy requirements, and decreased hazardous waste oil generation. The result is that the Natchez team has eliminated nearly 2 million pounds per year of toxic waste. The team continues to work on its goal of reducing toxic emissions to 1 % of the 1987 level by 1995. The next project will focus on eliminating ammonia wastes.

Dow Chemical Company's chlorinated ethane products facility in Freeport, TX, produces raw materials used in Saran Wrap plastic film, herbicides, and latex paints. The waste reduction team realized that they could reduce the amount of product lost in a byproduct stream, as well as improve the quality of their by-product hydrochloric acid stream. The team changed the production process to eliminate the use of excess ethylene, which contaminated a hydrogen chloride stream during production. This reduction allowed Dow to produce high quality hydrochloric acid. At this same facility, Dow improved the separation of a by-product from the vinylidene chloride recovered during separation. These waste reduction changes produced a high quality hydrochloric acid for use at other facilities. Ethylene and vinylidene chloride, which had been previously sent to a thermal oxidizer as waste, are now recoverable products.

Many more companies are still in the early stages of identifying opportunities that will reduce waste generation and save money or have not yet begun a program. The focus of

STANDARD INDUSTRIAL CATEGORIES

Figure 2 True Costs of Waste Generation and Management for 70 "typical" manufacturing plants in the United States.

COST CATEGORIES

□ TRANSPORTATION

H RAW MATERIAL

STANDARD INDUSTRIAL CATEGORIES

Figure 2 True Costs of Waste Generation and Management for 70 "typical" manufacturing plants in the United States.

government efforts, described below, is to provide better incentives for firms to begin pollution prevention programs and to provide them with technical information and hands-on assistance to get started.

Understanding how to reduce pollutant generation and save money is the key to building a successful pollution prevention program in a company. And the first step to saving money is to understand how to calculate the true costs of waste management. In many cases, companies include only the costs of waste treatment, disposal, and transportation in their estimates of waste management costs. The true costs of waste management, however, must also include the value of materials contained in each waste stream generated (i.e., materials in waste streams are raw materials that were not turned into product) and the labor, management, and energy costs associated with the generation and management of "wastes." The difference between conventional calculations of waste management (treatment, disposal, and transportation costs) and the true costs of waste management can be dramatic. Figure 2 illustrates this difference.

Figure 2 shows that the true costs of waste management for 70 "typical" manufacturing facilities in the United States2 are 85-95% greater than conventional cost estimates that focus

2In this analysis [6], 10 "typical" plants were drawn from each of seven different Standard Industrial Categories (SICs) contained in the database of a private engineering firm that specializes in completing pollution prevention opportunity assessments. The seven SICs included in the anlaysis were 20—food and kindred products; 22—textile mill products; 28—chemicals and allied products; 30—-rubber and miscellaneous plastics products; 32—stone, clay, glass, and concrete products; 34—fabricated metal products, except machinery and transportation equipment; and 37—transportation equipment.

only on the costs of treatment, disposal, and transportation. In conventional estimates, companies do not consider the value of the materials in the waste stream or other costs related to managing wastes.

A look at the true cost of waste generation and management often compels companies to complete an analysis of options for reducing these costs—a pollution prevention opportunity assessment. A pollution prevention opportunity assessment consists of

1. Identification of individual waste streams, their composition, and their origin in the production process

2. Identification of the amount of raw material purchased that was eventually discarded as waste

3. Estimating the value of the materials disposed of, using original purchase prices

4. Identification of all other costs associated with generating and managing each waste stream

5. Evaluation of options that would reduce the use and generation of the waste materials

After completing a pollution prevention opportunity assessment, many companies find they have been using more materials than necessary, not managing inventory carefully, not managing quality control carefully, using highly toxic raw materials when a safer substitute could be used instead, or using and wasting costly materials "because we have always done it that way." In many cases companies find more efficient and cheaper ways to manufacture their products and generate less waste with little or no investment of capital. Figure 3 illustrates a true cost calculation for a typical waste stream. To encourage more companies to pursue pollution prevention, EPA began building a pollution prevention program in 1987. At that time EPA focused its efforts on the prevention and recycling of industrial solid hazardous waste. By 1988, EPA expanded its efforts to all agency

Treatment, storage, and disposal facility cost: The plant generates 24,000 gal of waste coolant per year. Disposal of the waste coolant at a treatment, storage, and disposal facility costs $0.20/gal 24,000 gal/yr x $0.20/gal $ 4,800

Waste transportation cost:

The waste coolant costs $0.15 per gallon to transport to the treatment, storage and disposal facility.

Wasted raw material cost:

The coolant becomes contaminated with oil and grease under current operations and can no longer be used. The coolant was purchased for $1.00/gal. 24,000 gal/yr x $1.00/gal

$24,000

Labor cost:

100 hours per year of plant labor time ($10.00/hr).

10 hours per year of management time ($20.00/hr).

10 hr x $20.00/hr Other costs

Future waste disposal liability costs

none unknown

Total coolant waste generation costs

$33,600

Figure 3 Analysis of costs for waste stream 1: Waste coolants. (From Ref. 6.)

programs and began working with states and industry to seek out new opportunities. EPA developed a publicly accessible computerized Pollution Prevention Information Clearinghouse (free of charge to users) that contains hundreds of process-oriented examples of pollution prevention and recycling techniques. Information on contacting the clearinghouse is provided in Section IV.

EPA developed a series of user guides to help companies begin their own pollution prevention efforts. EPA's Facility Pollution Prevention Guide [7] is a field-tested handbook for manufacturers that describes how to form internal teams, gather necessary process and waste data, identify in-plant opportunities, analyze costs and savings, and set priorities among projects.

In 1991, EPA initiated the 33/50 program—a program that encourages companies to voluntarily commit to reducing pollutant generation 33% by the year 1992 and 50% by the year 1995. To date, over 600 companies have joined the program. This enthusiastic response indicates that pollution prevention is an important opportunity to save money while gaining favorable public recognition by being good corporate citizens.

About 45 states have pollution prevention assistance programs in place. These state programs provide on-site technical assistance, telephone information, and written guidebooks on how to conduct an assessment of a plant's pollution prevention opportunities for many specific waste streams. (These guidebooks are also listed in the Pollution Prevention Information Clearinghouse.) Many states provide an invaluable and unique service to many companies that is free and nonregulatory, saves money, and improves their public image.

The American Institute of Chemical Engineers and the American Institute for Pollution Prevention have published an engineering workbook of practical pollution prevention problems [8] that has been distributed to chemical engineering departments at universities throughout the country.

The workbook provides problems in six areas:

Life cycle analysis (an analysis of a product life from conception through design, production, use, and eventual disposal)

Identifying and setting priorities for managing pollutants from industrial sites

Selection of environmentally compatible materials

Design of unit operations for minimizing waste

Economics of pollution prevention

Process flowsheeting for minimizing waste

One of the problems is reprinted below.

Problem 153

Chemical Engineering Topics. Mass balances, engineering Economics

Pollution Prevention Concepts. Design of unit operations for minimizing waste, reducing unit size to reduce waste.

Background. A facility manufactures sheets of composite material for use in the aerospace and sporting goods industries. The composites are made by coating fiberglass or Kevlar fabrics with the liquefied resin. As shown in Figure 4, the coating process takes place in a pan containing the resin. The resin is dissolved in solvent, and a heat curing process drives off excess solvent from the composite to make the finished product. At the end of each run, the resin pan must be emptied, rinsed, and cleaned. This results in a

Prevention Pollution Policy

hazardous waste (rinsate, leftover solvent, and resin), which is then either partially recycled or incinerated.

Treater pans must be at least 10 in. wider than the product being coated to provide clearance for machinery, but when the facility's operating records were examined, it was discovered that the pans were excessively wide. This results in unnecessary waste generation. Plant data for the percentage of production at each fabric/treater pan width combination are given in the following table:

Fabric width Treater pan width Percent of (in.) (in.) production

32

60

40

38

78

20

50

84

15

44

84

5

50

86

9

60

86

11

It is proposed that blocks molded to fit into the ends of the pans be used to ensure that the effective treater pan width be exactly 10 in. wider than the fabric being coated. The blocks would have a one-time cost of $ 1000 and would not require removal of the pans. An operator would only have to remove the last block and insert the block appropriate for the next run. Your task is to consider the economic viability of this option, given that in a 9-month period there are 1369 resin treater cleanouts. The pans have a wetted cross-sectional area of 0.22 ft2, and the specific gravity of the resin is 1.1. The cost of the resin in $1,64/lb; the cost of the incinerating resin waste is $0.14/lb.

Problem Statement. Neglect interest and calculate how long it would take for the molded blocks to pay for themselves. Note that when the blocks are used, some incineration cost is avoided and less resin is thrown away. Ignore the volume of resin in the recirculation reservoir, and assume that the amount of rinsing required is not changed by the blocks. Also assume that all the waste is incinerated.

Solution to Problem 15

Average treater pan width (before reduction):

60 x 0.4 + 78 x 0.2 + 84" x 0.15 + 84" x 0.05 + 86" x 0.09 + 86" X 0.11 = 73.6 in.

Minimum possible average treater pan width:

42" x 0.4 + 48" x 0.2 + 60" X 0.15 + 54" x 0.05 + 60" x 0.09 + 70" x 0.11 = 51.2 in.

Cost of resin and incineration without the use of blocks:

igtlMM 1*21 «( (»$») (,!£) = $225,800/9 mo Cost of resin and incineration with the use of blocks:

= $157,000/9 mo Daily savings:

Payback period would be about 4 days.

(Note: The material for this problem resulted from a waste minimization audit sponsored by a grant from the California Department of Health Services.)

EPA began developing a more focused approach to pollution prevention, known as the Design for the Environment (DFE) program, in 1992. The program has several main facets that focus on particular industries and professional areas. For example, EPA has initiated two industry-specific projects:

1. The dry cleaning project explores alternatives for dry cleaning processes. Industry groups are active participants and are involved in comparative risk assessment, performance evaluations, and cost analysis of the various alternatives explored.

2. The printing project brings together several hundred printing companies in an effort to find safer substitutes for the chemicals used in the printing industry (e.g., inks, press washes).

The DFE program is also exploring design opportunities in crosscutting professional areas. For example, an effort is under way to standardize "true cost" waste management accounting

$(1.64 + 0.14) lb for accountants in companies of all types. Another project looks at initiatives the insurance industry could pursue to better factor pollution prevention opportunities into underwriters' evaluations of corporate risks. Contacts for the DFE program are listed in Section IV.

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