automated economic analysis model for hazardous … prevention, ob- jective measurement methods to...

ISSN 1047-3289 J. Air Waste Manage. Assoc. 4 0 1004-1011 (1990)

Automated Economic Analysis Model For Hazardous Waste Minimization

Seshasayi Dharmavaram, J. Brian Mount and Bernard A. Donahue US. Army Construction Engineering Research Laboratory-Environmental Division Champaign, Illinois .

The US. Army has established a policy of achieving a 50 percent reduction In hazardous waste generation by the end of 1992. To assist the Army in reaching this goal, the Environ- mental Divlsion of the U.S. Amy Construction Engineering Research Laboratory (USACERL) designed the Economic Anatysis Model for Hazardous Waste Minimization (EAHWM). The EAHWM was designed to allow the user to evaluate the life cycle costs for various techniques used In hazardous waste minimization and to compare them to the life cycle costs of current operating practices. The progam was developed In C language on an IBM compatible PC and is consistent with other pertbent models for performing economic analyses. The potential hierarchical mlnlmizatlon categories used In EAHWM Include source reduction, recovery and/or reuse, and treatment. Although treatment is no longer an acceptable minimization option, its use is widespread and has therefore been addressed In the model. The model allows for economlc analysis for minimization of the Army’s six most important hazardous waste streams. These Include, solvents, paint stripping wastes, metal plating wastes, industrial waste-sludges, used oils, and batteries and battery electrolytes. The EAHWM also includes a general application which can be used to calculate and compare the life cycle costs for minimization alternatives of any waste stream, hazardous or non-hazardous. The EAHWM has been fully tested and implemented in more than 60.Army installations in the United States.

In 1984, amendments to the Resource Conservation a n d Recovery Act [RCRA] of 1976 (42 USC 6901 e t seq),l also referred to as the Hazardous and Solid Waste Amendments [HSWA], required significant changes in the way

Implications

The EAHWM was developed to help Army decision makers find and evaluate viable minimization alternatives to current hazardous waste management practices. This tool has been widely accept- ed throughout the Army and is being assessed by the US. Navy and the Department of Defense General Supply Center. Law and policy makers in the government and private industry can also use the model to compare minimization alternatives to current hazardous waste management practices. They can then make deci- sions based on the total life cycle costs, annual savings, savings to investment ratio and the dis- counted payback period of the various alternatives.

hazardous wastes are managed within the United States. In July 1985, the Environmental Protection Agency [EPA] issued a set of regulations which began the process of implementing the 1984 amendments.

Among the federal regulations, is a requirement that every generator of Hazpdous Wastes [HW] who produces in excess of 1,000 kilograndmonth cer- tify that he or she has a Hazardous Waste Minimization [HAZMIN] program in operation when HWs are mani- fested. Biennial reports are required which describe efforts taken during the year to reduce the volume and toxicity of wastes generated, and the changes in volume and toxicity of waste achieved during the year.2 In October 1986, regulations were issued to clarify the sta- tus of small quantity generators of HW (100 to 1,000 ki l~gramdmonth) .~ Un- der the 1986 regulations, small quantity generators are now required to make a good faith effort to minimize HW generation and implement the best available treatment, storage, or disposal alternatives where economically feasible.

In November 1986, the EPA issued the first set of restrictions regarding

land disposal of HW.4 Under the No- . vember restrictions, untreated and concentrated spent solvents were re- stricted from land disposal. Deadlines were extended for other solvent waste streams because at the time it was felt that sufficient nationwide capacity for treatment did not exist. The 1984 HSWA have identified a schedule for banning all hazardous wastes from land disposal by May 1990.

In the broadest sense, hazardous waste minimization may be defined as the process of reducing the net outflow of HW effluents or air emissions from a given source (or generating process). Minimization would include any source reductions in the generation of hazardous wastesfemissions as well as any recycling activities which would result in either (1) a reduction id the total volume or quantity of hazardous waste(s) or (2) a reduction in the toxicity of the hazardous waste(s) generated. Treatment options such as incineration (thermal destruction), with effec- t ive ai r pollution controls, were considered viable techniques for hazardous waste minimization. Currently, the EPA does not categorize treatment under waste minimization. However, it is still widely practiced and is therefore included in the model. Waste minimization, therefore, might be achieved through any single, or combination of the following p r o c e s ~ e s . ~ ~ ~ ~ ~

I. Source reduction

A. Product substitution--the substitution of less hazardous chemicals for more hazardous chemicals (e.g., substitution of aqueous cleaners for organic halo- genated solvents in vapor degreasing) .

1. Good housekeeping practices-including waste stream segregation, improved inven- tory control and han- dling procedures, employee training, spill/

B. Source control

Copyright 1990-Air & %-ate Management Association

J. Air Waste Manage. Assoc. 1004

leak prevention, objective measurement methods to determine useful remaining life of a hazardous material and scheduling improvement.

2. Input material modification-including input purification and input substitution.

3. Technology modification-including improved controls, process modifications, equipment changes, energy conservation, and water conservation.

PI. Recovery/Reuse A. Use/Reuse-as an ingre-

dient in a process or an effective substitute.8.9

B. Reclaim-processed to re- cover usable product and/ or regeneration.10

111. Treatment-destruction or degradation which reduces the volume and/or toxicity with minimal generation of residual hazardous materials.

As the US. Army continues to expand its efforts to minimize the production of hazardous wastes on its installations in both the continental United States [CONUS] and outside t h e cont inenta l Uni ted S t a t e s [OCONUS], efforts were intensified for development of an economic model for evaluating the life cycle costs of the various techniques used for minimization and complete elimination of hazardous wastes. In many instances, minimization is a cost effective means of conducting business and will reduce costs (particularly given the future ban on all hazardous wastes from land disposal as outlined in the HSWA).I In addition to reduced disposal costs, waste minimization will also reduce present and future liability costs for the Army. Recognizing the importance of economics, Army HAZMIN policy now requires an economic analysis of HAZMIN alternatives which are under consideration by an installation.

This paper emphasizes the technical and economic rationale for waste minimization by generators of hazardous waste on Army installations. It reviews the technique and economic analysis methodology as it pertains to hazardous waste minimization and describes the development of a PC-based computerized model for evaluating and comparing hazardous waste minimization alternatives.

Policies

An average quantity of approximately 102,000 metric tons of hazardous wastes are generated annually on Army installations in the continental United States [CONUS]. Of this 102,000 metric tons, approximately 90 percent, is generated from industrial operations in the Army Materiel Command [AMC]. The Army's Forces Command [FORS- COM] and its Training and Doctrine Command [TRADOC], generate most of the remaining hazardous wastes. All total, there are 108 Army installations in CONUS which generate hazardous wastes (60 AMC, 26 FORSCOM, and 22 TRADOC).

As far as the DoD is concerned, the only limit which is to be set on the minimization of HW is its complete and total elimination." DoD policy is to at- tempt to eliminate generation of HWs and then treat residual HW for volume or toxicity reduction. All waste streams are to be examined according to these criteria with the intent of eliminating generation of HWs by 1992.

The Army's policy is to achieve a t least a 50 percent reduction in the quantity of HW produced by its Major Commands [MACOMS] by the end of calendar year [CY] 1992. To achieve this 50 percent reduction goal, AMC has established year-by-year reduction goals which utilize 1985 HW generation data as the baseline. (Volume of HW generated in 1985 = 100). These goals are presented in Table I. Both FORS- COM and TRADOC have yet to estab- lish similar HW reduction goals.

Table I. reduction goals.

Overall AMC hazardous waste

Calendar year

1987 * 1988

1 1989 1990 1991 1992

%Reduction as compared to

CY 1985

12.5 20 25 30

37.5 50

Source: Army Material Command.

To put this figure of a 50 percent reduction in perspective, Table I1 provides estimated quantities of all DoD generated hazardous wastes by major waste type categories.12 For purposes of comparison, Table I11 lists the hazardous wastes generated by major industrial processes at AMC installations in 1985. The wastes common to both TRADOC and FORSCOM installations which account for the remaining7 to 10 percent of total Army hazardous

waste generation are: cleaning and degreasing solvents, waste oil, batteries/ battery electrolytes, contaminated fu- els, waste ammunition powder, paint stripping wastes, and photographic wastes.

As part of its HW reduction plan, the DoD initiated a Used Solvent Elimina- tion [USE] program in 1984. The stat- ed goal of the USE program is the elimination of the disposal of recyclable solvents as wastes.13 In keeping with its overall policy on HW minimization, the DoD has indicated that the disposal of organic solvents as waste is not acceptable. Exceptions are made, however, for that portion of the waste stream which cannot be recycled (e.g., still bot- toms) or for small volume generators (less than 400 gallondyear total for all solvents).14 An Economic Analysis [EA], detailing the available minimization alternatives and associated costs and savings, is a key component of any successful USE program a t the installation level.

A major source of funding for HAZ- MIN projects has been through the De- fense Environmental Restoration Ac- count [DERA]. Where the projected payback from a project is expected to be one year or less, funding is also available from the Defense Productivity Enhancing Capital Investment [PECI] program. In such instances, any account may be used to finance minimization efforts and the installation will directly benefit from the resulting savings. However, with a multiplicity of alternative minimization techniques available for various HW streams, it is imperative that installation-level environmental personnel have a t their disposal a uniform and impartial method for evaluating the economic value of these various hazardous waste and hazardous materials minimization techniques when requesting DERA funds. The economic analysis [EA] model developed here, is designed to provide an uniform and impartial means for evaluating the economic value of alternative hazardous waste minimization strategies.

The objective of this effort was to develop and demonstrate an economic model for evaluating the life cycle costs for the various techniques used in hazardous waste minimization. This model was to be consistent with the guide- lines for conducting economic analyses as specified in DoD Instruct ion 7041.3.15 Five separate tasks were defined as necessary to successfully complete this objective.

The first task was to identify those waste streams which generated the ma- jority of the hazardous wastes generat-

Objective

1005 July 1990 Volume 40, No. 7

ed by Army installations and where techniques for minimization allowed for a high potential to reduce the generation of hazardous wastes.

The second task was to identify those techniques which have been shown to be both technologically and economically feasible for minimizing the generation of hazardous wastes.

The third task was to review all current guidance documents on performing economic analyses as related to equipment procurement, particularly hazardous waste minimization equipment, which have been prepared for the Department of Defense [DoD] and each military service, including their major commands [MACOMs]. Similar models used by the private sector were to be evaluated when it was determined necessary in order to develop a working model consistent with DoD's guidance.

The fourth task was to develop a methodology and a computer model which would allow for direct comparison of the life cycle costs of alternative hazardous waste minimization techniques to those of current operating procedure.

The fifth and final task was to field test the proposed economic model a t AMC, FORSCOM, and TRADOC installations for the various types of hazardous wastes generated.

Approach

To accomplish the tasks indicated above, a literature search of all perti- nent models for performing economic analyses was conducted. From this literature review and supporting computerized models, a framework for performing an economic analysis of hazardous waste minimization alternatives emerged.

Hazardous waste generation data a t Army installations and cost information required for conducting economic analyses were reviewed. Eiforts were undertaken to quantify the degree of hazard associated with each waste stream (or type), the number of loca- tions where the waste stream occurs (commonality), the degree of hazard associated with each waste stream, the treatment, storage, and disposal [TSD] costs associated with the stream, and finally, the estimated potential to minimize the hazardous waste stream with existing techniques.

These initial efforts lead to a decision that economic analyses for hazardous waste minimization alternatives be limited to six prominent waste streams. The six priority waste streamdtypes selected for further analysis were: (1) used solvents from cleaning and degreasing operations, (2) wastes from paint stripping operations, (3) wastes from electroplating operations, (4) sludges from industrial wastewater

Table 11. Estimated quantities of hazardous wastes generated annually for 15 DoD waste type categories.

Annual waste Percent of total quantities annual DoD

Waste generated hazardous waste generation category (metric tons)

Aqueous solvents 198,673 34 Toxics 97,976 17 Aqueous oils 94,347 17 Corrosives 44,452 8 IWTP sludges 39,916 a

Ignitables/flammables 36,287 6 Pesticides 39,009 7

Paints & paint sludges 22,680 4 Concentrated oils 15,422 3 Concentrated solvents 8,165 1 Reactives 6,350 1 Spill residues 4,536 <1 Empty containers 3,629 <1 Batteries, lithium 1,814 <1 Batteries, non-lithium . 1,814 <1 Total ' 615,070b 100

a Percentage breakdown is not provided because industrial waste treatment plant (IWTP) sludges result from the management of some of the other 14 categories of waste types. b 72,575 metric tons of demilitarized ammunition are excluded from the total; individual figures are rounded to nearest 1000 metric tons. Source: ICF Technology, Least-Cost DoD Hazardous Waste Management Strate- gies, Final Draft Report, prepared for the DoD Environmental Leadership Pro- ject Office (15 June 1987), pp 2-2-2-4.

treatment plant operations, (5) waste petroleum oils and lubricants, and (6) batteries and battery electrolytes.

Having identified the significant waste streams to be considered, the next step was to identify those techniques or strategies which have been shown to be both technically and economically feasible for minimizing the generation of hazardous wastes. For each of the six waste streams, appropri- a te minimization techniques were identified in the source reduction, recovery/reuse, and treatment categories. These specific waste minimization techniques, were subsequently analyzed to identify appropriate economic parameters in an effort to codify the financial components for each technique.

Waste Minimization Techniques

Minimization techniques for the six waste typedstreams selected for inclu- sion in the model were evaluated according to the strategy suggested by Freeman.5 Some of the minimization techniques included in the model are presented briefly in the remainder of this section.

Cleaning and Degreasing Solvents

Organic solvents are used on Army installations for both cold cleaning (including wipe cleaning, dip tank cleaning, and diphase cleaning) and vapor degreasing operations. Aliphatic hy- drocarbons such as Stoddard type sol-

vents, kerosene, varsol, and other min- eral spirits are used in cold cleaning operations to remove dirt, oil, and grease. Trichloroethylene, perchlor- oethylene, or l,l,l-trichloroethane are typically used in vapor degreasing operations.16

Among the good housekeeping practices that are possible, efforts to reduce air emissions are probably the most beneficial. For both cold cleaning and vapor degreasing operations, proper tank covers (or lids) should be installed and closed during the periods of inac- tivity. Increasing the freeboard height (the distance from the top of the liquid

Table 111. generated at AMC installations in 1985.

Quantity of hazardous wastes

Quantity generated

Process (metric tons)

Load and pack operations 25,000 Waste treatment sludges 16,773 Pyrotechnic operations 13,759 Munitions demolition 5,920 Metalwork 2,221 Plating 1,629 Cleaning 1,409 Painting 1,259 Other hazardous wastes 818

804 Vehicle maintenance Stripping 159 Electrical maintenance 98 Battery shop operations 29

Total 69,878 Fuel operations 0

Source: Army Material Command.

1006 J. Air Waste Manage. Assoc.

to the top of the tank) could reduce the solvent emissions from 27 to 46 percent.17 Installation of a freeboard re- frigeration device (chiller) to chill the air above the vapor zone of a degreaser can reduce solvent consumption by 60 percent.17 Protecting the equipment from air currents and excessive turbu- lence near exhaust ducts can reduce solvent losses. In degreasing operations, the use of organic solvents can be eliminated by substituting aqueous cleaners and/or peel coatings in certain applications.

Batch distillation is a commonly used means of reclaiming spent solvents on Army installations.’6J8 The reclaimed product can be reused in cleaning and degreasing. This recycling of solvents can be accomplished either onsite by installation personnel or by employing the services of an offsite contractor to pick up used solvent and return the recycled product to the installation.

Finally, incineration of the organic solvent waste stream may result in its complete destruction, forming COz and H20. Treatment by incineration is the last resort after recycling of solvents has been attempted.

’

Paint Stripping Wastes

Throughout the Army, several types of both wet and dry paint stripping operations are used in removing paint from equipment surfaces, walls, etc. Dry stripping is often performed with sand, glass beads, or vegetable matter (corn cobs, rice hull, walnut shells, etc.). Wet chemical stripping using a solvent with a methylene chloride base is perhaps the most common technique employed.

As with cold cleaning and degreasing solvents, substitution of less toxic strippers for methylene chloride/phe- no1 based solvent stripping agents may be an effective strategy.l7Jg

Plastic media bead blasting is an abrasive blasting technique that has been tested successfully by both the Air Forcel9 and the airline industry,20 and has been determined to be both an effective substitute for wet chemical strippers and other forms of dry abrasive blasting and a cost effective means of controlling disposal costs.

Reclamation of stripping solvents from the mixed aqueous/organic waste stream either may or may not be eco- nomical, depending on the concentra- tion of the solvents and whether proper segregation procedures were followed. A phase separation stage (accomplished by decantation/sedimentation, filtration, flotation, or centrifugation) is required for the separation of solids.2l Organic components may be subsequently separated by either air/ steam-stripping, fractional distillation,

July 1990 Volume 40, No. 7

solvent extraction, or carbon or resin adsorption.21

The aqueous waste streams resulting from wet chemical paint stripping operations must be treated to remove all organic components before discharge into a Sewage Treatment Plant [STP] or Publicly Owned Treatment Works [POTW]. Preliminary treatment of the water for pH adjustment and separation of solids, and organic component transformation methods such as bio- logical degradation and chemical oxidation of organics may be used.21

Metal Plating Wastes

Metal plating operations are common primarily a t AMC installations. Hard chrome plating is used for re- building worn-out parts. Decorative chrome plating uses the same plating bath(s), but has much shorter resi- dence time. In terms of frequency cadmium plating is the second largest plating operation. Cadmium plating baths consist of cyanide salts of cadmium and sodium, cadmium oxide, and sodium hydroxide. Other, less frequent plating operations include nickel, zinc, and copper.

Ion vapor deposited aluminum has been found to be a effective substitute for electroplated cadmium on steeLZ2 Substitution of input material in other plating baths may reduce treatment costs. For decorative chro4e plating, trivalent chromium formulations have been used in place of hexavalent chromium plating solutions. Substitution of non-cyanide baths for cyanide baths has also been tried successfully in zinc plating.23

Purification of plating baths by filtration, chemical treatment, carbon treatment, physicallchemical treatment, and/or electrolytic treatment may result in savings in the disposal costs of spent plating bath dumps. The choice of treatment techniques is dependent on the type of bath and operating condi t i0ns.2~~~~

Tbchnological modifications which reduce the amount of rinse water used can be simple to implement (space per- mitting). These modifications include the installation of water supply control valves and/or conductivity controllers and timers. Perhaps the single most effective rinse water modification is the use of multiple rinse tanks with move- ment of parts countercurrent to rinse water flow. The quantity of rinse water required is reduced by 90 to 99 percent when the number of tanks is increased from one to three.27 Drag-out recovery of concentrated plating chemicals also represents a cost-effective technique of reducing hazardous wastes.25

Hard chrome plating processes may be modified and retrofitted as Innova- tive Hard Chrome Plating [IHCP], also

known as the “Cleveland” process (using two bus bars, reversible racks, and conforming anodes). IHCP has been successfully demonstrated by the U.S. Navy as a cost effective substitute for conventional hard chrome plating.26 In rinse waters, hexavalent chromium in rinse waters from chrome plating operations must be reduced to a trivalent form before precipitation a t a conventional wastewater treatment plant.27

I

lndustrlal Wastewater Treatment Plant Sludges

At AMC installations, hazardous wastes in rinse waters often enter In- dustrial Wastewater Treatment Plants (IWTPs) from industrial operations. Conventional treatment plants generally include both hexavalent chromium reduction and cyanide oxidation processes as pretreatment steps.28 The single greatest potential for minimizing wastes a t an IWTP involves the reduction in the amount of sludge generated through further dewatering29 or by al- tering the precipitation process. Both Soluble Sulfide Precipitation [SSP] or Insoluble Sulfide Precipitation [ISP] offer possibilities for cost minimiza- t i ~ n . ~ O

Waste Petroleum and Lubricating Oils

Used crankcase oils, transmission oils, final drive oils, hydraulic fluids, and other petroleum- and synthetic- based products are generated on Army installation^.^^ Crankcase oils are usu- ally contaminated with gasoline, addi- tives, combustion products, wear met- als, dirt and coolant. Techniques for draining and transfer of oil from crank- cases of motor vehicles can be modified for source reduction. A Fast Lube-Oil Change System (FLOCS) has been developed for commercial fleet applications that can minimize the contamina- tion reducing the costs of recycle and/ or d i s p o ~ a l . ~ ~ ~ ~ ~

Unlike used solvents, onsite reclamation of used oils is generally not viewed as an economically practical minimization alternative. Energy recovery by the burning of used oils in industrial boilers is the best possible onsite recycle/disposal method.

Batterles/Battery Electrolytes

There are a wide variety of batteries currently in use at Army installations including lithium-sulfur dioxide (Li- Sod, nickel-cadmium (NICAD), lead- acid, magnesium, alkaline, mercury, and LeClanche (Zn-MnO2) batteries.34 Once the installation has determined that a battery has served its useful life, it can be sold to salvage operators or smelters for reclamation (particularly attractive as an option for reclaiming

1007

I Hazardous Waste c

Alt ernat ives

c

Yes Rewverymeuse * Alternatives

Treatment Alternatives

No

4

1

Residue I ' Disposal I I-,----I

Results a

Figure 1. (EAHWM).

A conceptual decision tree used In the Economic Model for Hazardous Waste Minimization

lead-acid batteries). If batteries cannot be salvaged, then they must either be properly disposed off in a commercial landfill or incinerated in a permitted facility.

Computerized Economic - Analysis Model

The hazardous waste minimization techniques presented for the six waste streams have been incorporated into a computer model for performing an engineering economic analysis. Written in C language for an IBM compatible PC, the EAHWM (Economic Analysis for Hazardous Waste Minimization) model is a tool that installation manag- ers can use in assessing the life-cycle costs of implementing various minimization alternatives. A conceptual decision tree which underlies the logic used in the computer model is shown in Fig- ure 1.

Some of the assumptions made in the development of the model were: (1) Implementation of minimization

techniques is assumed to be possible at every installation. The costs

1008

a t each installation, however, would vary by the typelsize of the technique employed which would be dependent upon the type and quantity of hazardous waste generated. ~

(2) Onsite storage costs of hazardous wastes include actual costs of con- structing a conforminglnon-conforming storage facility as well as the costs of complying with RCRA regulations.

(3) All transportation services for removal of hazardous wastes offsite are assumed to be privately owned. All transportation costs for hazardous waste removal are assumed to include costs for off-installation disposal (whether the wastes are being recycled, landfilled, or incinerated).

(4) Onsite landfills for disposal of hazardous wastes on Army installations are not considered in the development of this model as it is assumed that questions regarding economics of scale and high per- mitting costs would significantly favor the use of existing commer-

cial landfills. (5) Further, i t is assumed that all tech-

niques considered in the model can be implemented on an Army base. This assumes that space for the equipment exists, that no environmental constraints prohibit the implementation, and that installation personnel are both capable and willing to be trained in use of the techniques.

(6) Finally, it is assumed that Army liability for hazardous waste management may occur either: (1) directly, as a result of cleanup costs associated with the release of hazardous wastes into the environment, or (2) indirectly, through increased prices charged by commercial landfil ls or incinerat ion facilities in anticipation of future legal liabilities.

?'he EAHWM model allows the user access to specific submodels for calcu- lating the life cycle costs of appropri- ately identified minimization alternatives for each of the six waste streams. Additionally, there is a generalized form of a life cycle cost model applicable to any minimization alternative or waste stream whether it be hazardous or non-hazardous (Figure 2). Once the user chooses a waste type, he or she is taken to a File Menu (Figure 3) which lists all previous files of this same waste type (e.g., all solvent files or all general model files) along with a selection for entering new problem information and a separate screen for entering and al- tering default values.

- WasteTypes

Solvents Paint Stripping Metal Plating I W P Sludges Used Oil Batteries General Model

Setup Quit

Figure 2. Waste types screen.

For the minimization alternatives identified in the model (e.g., reducing rinse water usage in plating operations), default values for fixed cost parameters such as equipment costs (equipment, property acquisition, site preparation, etc.), research and development costs, and expected equipment replacement (all in 1988 dollars) are, provided based upon production v01-' ume. The user may elect to either accept these default values or input his or

J. Air Waste Manage. Assoc.

her own. Expenses for installation, logistics and procurement, and start-up are estimated as percentages of appropriate fixed costs (e.g., logistics and procurement is estimated as 7 percent of installed equipment Again, the user’ may choose to either accept the default values provided by the model or enter his own estimates.

Default values for recurring costs such as labor, maintenance and repair, utilities, sampling and testing, disposal, etc., are also provided by the model. Again, the user may choose to accept the default values provided (e.g., annual maintenance and repair is estimated at 5 percent of equipment costs), or enter his or her own values. Default values may be changed either globally or within a particular submodel (i.e., the default value of $ll/hr for laborers may be changed for all alternatives and all waste streams, or only for a particular minimization alternative such as onsite solvent distillation).

Alternative #3 Alternative #4 Alternative #5 Alternative #6

Comparison r

Old Files

Figure 3. File menu screen.

If the user selects a new problem, he or she is taken to the Minimization Concepts screen (Figure 4). Within the Minimization Concepts screen is the Problem Information screen, where the user is required to input information on the amount of waste produced, whether the waste is hazardous or non- hazardous, as well as any other information which may be necessary to esti- mate costs and which is applicable to all minimization alternatives for this particular problem.

Having entered the problem information, the user is now free to select between the three broad categories of minimization efforts defined previous- ly-source reduction, recovery/reuse, and treatment. (Figure 5 provides a “snapshot” of the nested EAHWM screens.) Selection of source reduction, for example, would provide the user with a screen which would further define the minimization alternatives according to whether they were product substitution or source control strategies. Selection of either of these alternatives would then take the user to the specific alternatives associated with that particular waste stream. For example, in the solvents waste stream, the user would further define the problem as either solvents used in cold cleaning or degreasing operations.

Mlnlmlzatlon Concepts

Source Reduction Recovery/Reuse Treatment

Figure 4. Minimization concepts screen,

By further selection of the source reduction substitution alternatives, a screen would be brought up which identifies the substitution strategies which are “costed out” by the model (i.e., those alternatives where operating parameters, cost calculations, and default values are contained within the model). In the particular example cited above, selection of degreasing solvents would present the following alternatives to the user-substitution of 1,1,1 trichloroethane for trichloroethylene and substitution of aqueous cleaning solvents for organic vapor degreasing solvents. An “other” alternative is also available for the user to enter in cost parameters for options other than those considered directly by the model.

Once the user selects a specific minimization alternative, say substitution of aqueous cleaning solvents, he or she

- WasteTypes

Solvents Paint Stripping Metal Plating IWTP Sludges Used Oil

is asked to provide further alternative information which is used in the specific calculations nested within that submodel. For substitution of aqueous cleaning solvents, for example, one of the questions the user is asked is the volume of his or her degreasing tanks. This value is subsequently used to calculate either costs or savings in such categories as disposal costs, potential liability costs, and replacement materials/raw materials.

The General Model, or the seventh “waste type” does not contain default values for equipment as do the specific submodels. Some defaults, however, such as the values for logistics and procurement, installation, etc., are active and will calculate values for their appropriate cost categories (e.g., installation costs are calculated as a percent of the total equipment costs which the user enters). Figure 5 provides an example of what the user might see as he or she selects the various options in proceeding from screen to screen.

Once the user has entered the appropriate cost information, the model will calculate net present values of investment over any time period using a mid- year or “continuous” discounting equations which approximate an average of “end-of-year” discounting factors commonly presented in many economic textbooks. “End-of-year” techniques

[

Batteries

1

I mlzatlon Concepts 1

I Default U Problem Information

Recovery/Reuse Treatment

Comparison Print

ion I I

Figure 5. ”Snaphot” of the various EAHWM model screens.

assume that cash flows occur precisely at the ends of years. Continuous discounting equations are more appropriate as they more closely resemble the steady disbursement of funds to cover project costa (e.g., salaries are typically paid either weekly or monthly).36

In comparing minimization alternatives, the model allows the user to calculate a Savings-to-Investment Ratio [SIR], which is the amount of future costs which will be saved divided by the amount of investment required t~ un- dertake the alternative, andlor the Dis- counted Payback Period [DPP], which is the time required for a project to accumulate enough savings to offset its investment costs. Where economic lives of the alternatives being compared are unequal, a Uniform Annual Cost [UAC] is calculated (UAC is determined by dividing the total dis- counted project cost by the sum of the discount factors for the years that the alternative yields benefits).

EAHWM is a deterministic model, dealing largely with certain, quartifi- able cash flows (e.g., capital investment costs, operating & maintenance [0 & M] costs, etc.). The flexibiIity of the model and the ease with which the default values and user inputted cost information can be changed, however, allow the user to develop multiple sce- narios or assumptions which can easily be compared-a process commonly referred to as sensitivity analysis.

EAHWM is not a stochastic model which allows the user to select a range for a category upon which probability distributions for cash flows are calculated. The defaults contained within the EAHWM model, while general in nature, nonetheless allow the unso- phisticated user the opportunity to perform a comprehensive economic evaluation of various hazardous waste minimization alternatives. By tailoring these defaults to the actual costs expe- rienced a t an installation, the model allows the sophisticated user the opportunity to fully explore the potential costs/savings resulting from implementing a minimization alternative. Because of this sophistication, it was felt that a stochastic model which would allow the user the opportunity to express his or her confidence about the value of a parameter by specifiying an uncertainty range around the best esti- mate was unnecessary and offered significant potential for abuse of the model. For users desiring such a stochastic approach, however, a financial analysis model developed by ICF, Inc. and based on Lotus 1-2-3, offers generators of hazardous waste the opportunity to specify confidence ranges of “best esti- mate~.”3~

The flexibility afforded by t h e EAHWM model is readily apparent to the first-time user. The extensive defaults file for each waste stream allows

the user to enter the model and with only minimal input, perform an economic analysis on any number of waste minimization alternatives contained within the model. By adjusting the default values to reflect specific operating conditions a t his or her installation (e.g., labor rates, disposal costs for solvents, etc.) the user can achieve an even more accurate picture of the total costs and benefits of the minimization options.

Extensively documented, context sensitive helps are available to the user simply by depressing the appropriate function key. Not only do the help screens provide the user with information on how default values were obtained, what default values are used in the calculations, and what the calculations contained within the program are actually accomplishing but the helps, also contain equipment prices for various size models of minimization equipment, producer addresses and tele- phone numbers (where available) and documentation of any assumptions made in the creation of the various equations comprising the submodels.

Although designed primarily for performing economic analyses of hazardous waste minimization options, the EAHWM model is not limited to hazardous wastes, or even wastes for that matter. Designed to incorporate all Army regulations for performing an economic analysis,’? the “general model” submodel of EAHWM can easily be used to evaluate the economics of any equipment purchases or product substitution strategy whether the pur- chase has to do with hazardous wastes or not.

The model has been field-tested a t a variety of AMC, TRADOC, and FORS- COM installations and implemented a t more than 60 Army installations as a standard methodology for determining techniques and assessing costs of hazardous waste minimization efforts. In the futyre, depending on the availabil- ity of funding, efforts will be made to expand the model to address minimization aspects for many of the other hazardous waste streams listed in Tables I1 and 111. Upon continued testing and data gathering, the potential exists to develop a knowledge-based system that can both teach and “learn” from the users.

Acknowledgments

The authors would like to acknowl- edge the funding provided by the U.S. Army Environmental Office under the Defense Environmental Restoration Account and the editorial assistance provided by Kristan Cockerill.

Disclaimer

The opinions and interpretations ex-

pressed in this paper are those of the authors and do not necessarily reflect the views of the Department of the Army, nor does the mention of trade names or commercial products consti- tute endorsement or recommendation for use.

References

1. With the intent of controlling the way solid waste materials are handled in the United States, the main thrust of RCRA was to enforce record keeping responsi- bilities on the generators and transport- ers of hazardous wastes, establishing a manifest system to provide for account- ability. The 1986 amendments may be found in “Hazardous and Solid Waste Amendments of 1984,” (PL 98-616), (8 November 1984).

2. Code of Federal Regulations, Title 40, Part 261 “Identification and listing of hazardous waste,” and Part 262, “Stan- dards applicable to generators of hazardous waste.”

3. Federal Register, “Hazardous management system; Standards for generators of hazardous waste,” U. S. EPA, VoI. 51,

4. Federal Register. “Hazardous waste NO. 190, pp 35190-35194 (1986).

management system; Land disposal restrictions,” U. S. EPA, Vol. 51, No. 216, pp 40572-40654 (1986).

5. H. M. Freeman, “Hazardous waste minimization-A strategy for environmen- ta l improvement,” J A P C A , 3 8 5 9 (1988).

6. Bechtel National, Inc., Waste minimization study for the Lawrence Liver- more National Laboratory, Final Re- port, UCRL--15883-Vol. 1 (December 1987).

7. ICF Associates, Guide to solvent waste reduction alternatives, Final Report, prepared for the California Department of Health Services (10 October 1986).

8. R. L. Immerman, “Recycle/reuse: The right answer,” Environ. Prof. 3:25 (1981).

9. Materials are either used or reused if they are either (1) employed as an ingre- dient in the formulation of a product or (2) employed in a particular function as an effective substitute for a commercial product (40 CFR 261.1 (c)(5)).

10. Code of Federal Regulations. Title 40, Part 261.1 (c)(4) “Identification and listing of hazardous waste: Scope and purpose,” (1988).

11. DoD Memorandum for Deputy of Envi- ronment, Safety and Occupational Health, OASA (I&L), Deputy Director for Environment, OAASN (S&L), Dep- uty of Environment, Safety and Occu- pation4 Health (SAD/MIQ), Director, Defense Logistics Agency, (on Hazard- ous waste minimization), (6 February 1987).

12. ICF Technology, Least-cost DoD hazardous waste management strategies, Final draft report, prepared for the DoD Environmental Leadership Pro- ject Office (15 June 1987).

13. DoD Memorandum for Secretaries of the Military Department Directors, De- fense Logistics Agency, (on Used solvent elimination (USE) program), (10 January 1984).

14. DoD Memorandum for Assistant Secre- tary of the Army (I&L), Assistant Secre- tary of the Navy (S&L), Assistant Sec- retary of the Air Force. (MRA&L), Di- rector, Defense Logistics Agency, (on Used solvent elimination (USE) program, interim guidance), (20 February 1985).

15. DoD Instruction Number 7041.3, Eco- nomic analysis and program euolua-

I010 J. Air Waste Manage. Assoc.

. _ - tion for resource management, (DoD 18

16. B. A. Donahue, M. B. Carmer, Solvent [cradle-to-grave’ management guide- lines for use a t Army installations, CERL Technical Report N-168 (De- cember 1983).

17. ICF Associates, Guide to solvent waste reduction alternative, Final report, prepared for the California Department of Health Services, pp 4-4-4-24, (10 Oc- tober 1986).

18. CH2M Hill, Industrial processes to reduce generation of hazardous waste a t DoD facilities, Phase 2 report: Evalua- tion of 18 Case Studies, prepared for the DoD Environmental Leadership Project and the U.S. Army Corps of En- gineers (J$y 1985).

19. CH2M Hill and Peer Consultants, Inc., Industrial processes to reduce generation of hazardous waste a t DoD facilities, Phase 3 report: Appendix A- Workshop manual plastic media paint stripping Hill Air Force Base, Ogden, Utah, prepared for the DoD Environ- mental Leadership Project and the U.S. Army Corps of Engineers (November 1985).

20. G. B. Duhnkrack, “Plastic blast me- dja-,? alternative to chemical strip- pin Pollut. Eng. 1954 (1987).

21. B. E. Blaney, “Alternative techniques for managing solvent wastes,” JAPCA 36:275 (1986).

22. D. E. Muehlberger, “Ion vapor deposi- tion of aluminum: More than just a cadmium substitute,” Plating and Surface Finishing 70:24 (1983).

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. October 1972).

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27. D. W. Grosse, “A review of alternative treatment processes for metal bearing hazardous waste streams,” JAPCA 36:603 (1986).

28. USACERL, Reference guide for Indus- trial Wastewater Treatment, CERL Technical Report N-85/06 (September 1985).

29. M. R. Bradbury, D. Thompson, Electro- plating sludge treatment technology development, Final summary report, prepared for the U.S. Army Toxic and Hazardous Materials Agency, (Febru- ary 1986).

30. Arthur D. Little, Inc., Soluble sulfide precipitation study, prepared for the U.S. Army Toxic and Hazardous Mate- rial Agency (December 1986).

31. Robert H. Salvesen Associated, Used oil and solvent recycling guide, Final report, prepared for the Department of the Naly, Naval Energy and Environ- mental Support Activity, Port Huen- eme, CA (June 1985).

32. D. W. Brinkman, M. L. Whisman, C. J. Thompson, Management of used lubricating oil at department of defense installations: A guide, NIPER B06711-1, prepared for DoD E Environmental Leadership Project Office, Washington D.C. (30 June 1986).

33. D. W. Brinkman, M. L. Whisman, C. J. Thompson, Management of used lubricating oil a t department of defense in- s ta l la t ions, F ina l repor t , NIPER

B06711-2, prepared for DoD Environ- mental Leadership Project Office, Washington D.C. (30 June 1986).

34. U.S. Army Communication Electronics Command, Battery dispositionldispos- a1 Handbook, Fort Monmouth, NJ (No- vember 1986).

35. Naval Facilities Engineering Com- mand, Economic Analysis Handbook, NAVFAC P-442, Alexandria, VA (June 1986).

36. Defense Logistics Agency, Economic Analvsis. DLAM 7041.1, Alexandria, VA (81 May 1985).

37. J. G. Karam, C. St. Cin, and J. Tilly, “Economic evaluation of waste minimization options,” Enuiron. Prog. R192 (1988).

Dr. Dharmavaram and B. A. Dona- hue are Environmental Engineers at the U.S. Army Construction Engi- neering Research Laboratory-Envi- ronmental Division, P.O. Box 4005, Champaign, IL 61824-4005. J. B. Mount, formerly with CERL, is now at the Walsh College of Accountancy and Business Administration, 3838 Livernois Road, P.O. Box 7006, Troy, MI 48007-7006. Address all inquiries concerning this article to B. A. Dona- hue at the above address. This paper was submitted for peer review on February 5,1990. The revised manu- script was received May 16,1990.

July 1990 Volume 40. No. 7

Harold M Englund Editor N C DEPT OF ENVlR0NMl Constance Scsnga & NATURAL RESOU

.Assistant Editor James D. Morton Production Superviror Barbara A. Yunk Editorial Auirtant gate Rau Technical Production histant

EDITORIAL REVIEW BOARD

Chester W. Spicer Battdle Manorial Institute

. Vicechairman William R. Pirmon

a t a r y George T. Wolff

Larry Anderson

Don Blumenthal

Yoram Cohen

D m Raearch Institute

General Motors Rescarch Labs

University of Colorado at Denver

Sonoma Technology

university of California, Los Angeles

Lawrence Berkeley Labs Mackede L. Davis

Michigan State University Bruce A. Egan

ENSR Research and Consulting Thomas R. Hauser

University of Cincinnati R. Nichols Hazelwood

IT corporation Walter W. Heck

Ron Henry

Phil Hopke

J-

U.S. Department of Agriculture

University of Southern California

Clarkson University

U.S. Environmental Proteaion Apencv John A. Jaksch

Consultant

University of Michigan

NSI Technology Services Corp.

Perry J. Samson

Bruce Stuart

BUSINESS STAFF Leonard F. Mafrica M v e a ; S i salee Manager

Carol Brinza

VOLUME 40 NUMBER 7

Total Human E ure: Basic Concepts, EPA Fie1

T h e To@ Human Exposure monitoring approach provides relative contribution of various pollutant S O U ~ S to public

Identifying Ecolo&al Indicators: An Environmen Assessment Pro

An overview of the E E r & r a m which will evaluate the effectiveness of Agency policies for protecting resources within various ecological systems. S. M. Bromberg

Acid Raii Emission Allowances and Future Capacity Growth in the Electric

An Analysis of the issues involved in the new source emission offset provision in recent acid

Research N z

Utility Industry

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Combined Ca(OH)2/NHS Flue Gas Desulfurization Process for High Sulfur

T h e removal of SO2 with atomization of a sraked lime slurry and supplemental injection of Coal: Results of a Pilot Plant Stud

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A Sim le M d e l fot SO2 Removal in the Duct InjectionProcess A simpt model bf the Duct-Injection process was developed based on heat and mass transfer li theories; the model was fitted to data obtained at proof of concept tests. P. Harriot

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. S. Dharmavaram, J. B. Mount, B. A. Donahue

Im act of “Designated Smoking Area” Policy on Nicotine Vapor and Particle

As a result of a “Designated Smokin Area” policy, general employee exposure to nicotine

W. M. Vaughn, S. K. Hammond

NOTEBOOK ,

and Dispersion M when the source and dispersion

D. J. McNaugthon

Some Evaluations of the Effect of Ambient Temperatures on Plume Rise Scalin results suggest that for dimatologically sharp changes in the ambient temperature

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Estimating Innovative Technology Costs for the SITE Program Four issues are identified and analyzed which arc thought to have a significant impact on the

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