United States
 Environmental Protection
 Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-87/057  Nov  1987
 Project Summary
Waste Minimization Audit  Report:
Case Studies of  Minimization of
Solvent Waste  from Parts
Cleaning and from Electronic
Capacitor  Manufacturing
Operations
  To promote waste minimization
activities in accordance with the national
policy objectives established under the
1984 Hazardous and Solid  Waste
Amendments to the Resource Conser-
vation and Recovery Act of 1976
(RCRA), the  Hazardous Waste En-
gineering Research Laboratory (HWERL)
of the USEPA Office of Research and
Development has undertaken a project
to develop and test a waste minimization
(WM) audit procedure.
  As part of this project, a total of 6
WM audits were  carried out in four
separate facilities. This report presents
the results of an on-site WM audit per-
formed at an electronic capacitor
manufacturing facility for  solvent
wastes. The report also describes the
WM audit procedure as it has developed
from the initial (pre-project) sequence
of steps, to the modified (post-project)
sequence that reflects the experience
gained during this HWERL project.
  This Prefect Summary was developed
by EPA's Hazardous Waste Engineering
Research Laboratory, Cincinnati, OH, to
announce key findings ot the research
project that Is fully documented In  a
separate report of the same title (see
Project Report ordering Information at
back).

Introduction
  To promote waste minimization activi-
ties in accordance with the national policy
objectives established  under the 1984
Hazardous and Solid Waste Amendments
to the Resource Conservation and Re-
covery Act of 1976 (RCRA), the Hazardous
Waste Engineering Research Laboratory
(HWERL) of the USEPA Office of Research
and Development has undertaken a pro-
ject to develop and test a waste minimiza-
tion (WM) audit procedure.
  As part of this project, a total of 6 WM
audits were earned out in four separate
facilities. The full report presents the
results of the on-site WM  audits per-
formed  at two  facilities that generate
solvent-bearing wastes. It also describes
the WM audit procedure as it has
developed from  the initial (pre-project)
sequence of steps, to the modified (post-
project)  sequence that reflects the ex-
perience gained during this project The
4 other audits,  2 dealing with cyanide
wastes and 2 dealing with heavy metal
and corrosives wastes, are discussed in
two separate reports.

Waste Minimization Audit
Procedure
  The main objective of the full report is
to provide useful guidelines for the con-
duct of a WM audit. The following sections
discuss  how a  WM audit fits into an
overall WM program and provide brief
descriptions of the principal elements of
a WM audit.

The Role of the WM Audit
In a WM Program
  The primary  objective of a waste
minimization program  is to  reduce the

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quantity and/or toxicity of waste effluents
leaving the production process. The es-
sential elements of a WM program include
the initiation and planning of the program,
the planning  and execution of a  WM
audit,  and the implementation of  the
recommended measures that emerge from
the audit process.
  During the  program initiation phase,
the commitment of top management to
reduce waste generation must be estab-
lished, which results in the development
of an organizational structure for the WM
program  and  in  the setting  of  waste
reduction goals for the entire organization.
The next step involves characterization of
waste generation rates and waste char-
acteristics. The program  planning step
follows, with the selection of the audit
team(s) to carry out the  actual auditing
phase. The auditing process constitutes
the most important element of the overall
WM  program, since it provides the key
inputs for the generation of WM options,
as well as for the decisions of  which
waste minimization measures should be
implemented. Following the audit, selec-
tion  of options for implementation  are
made based on feasibility analysis. Finally,
WM  measures go through the sequence
of design, procurement,  construction,
startup, and performance monitoring.


Waste Minimization Audit
Procedure
  The execution of a waste minimization
audit can be divided into three distinct
phases, as shown in Table 1. The overall
objective  of  the  pre-audit phase is to
gather and  analyze  the information
necessary to select a waste stream(s) for
the facility audit. The audit phase follows,
the objective of which is to develop a
comprehensive set of WM options and to
screen them. The  product of the audit
phase is  a  list of  options selected for
further  evaluation.  A  technical and
economic feasibility analysis is performed
for each selected option during the post-
audit phase of the program. This  phase
ends with the preparation of a final report.
The following paragraphs provide a brief
description of each audit step.

1.  Preparation for the audit
  The objective of this  step  is to gain
background information about the facility
to be audited. Preparation should include
examination of information sources re-
lated to the processes, operations, and
waste management  practices  at the
facility. The result of proper preparation
should be a well-defined needs list, in-
Table 1.    Recommended Waste Minimization Audit Procedure


                           Activities
Program
 Phase
Product
Pre-Audit       1. Preparation for the audit

               2. Pre-audit meeting and inspection

               3. Data compilation and waste
                 stream selection
Audit           4. Facility inspection

               5. Generation of a comprehensive
                 set of WM options

               6. Options evaluation
               7. Selection of options for feasibility
                 analyses
Post-Audit      8. Technical and economic feasibility
                 analysis
               9. Final report preparation
                                           • needs list/inspection agenda

                                           • notes

                                           • facility and process description


                                           • waste description

                                           • rationale for selection

                                           • notes

                                           • list of proposed options with written
                                             rationale

                                           • independent options ratings by audit
                                             team and by plant personnel
                                             followed by joint review

                                           • list of selected options


                                           • options interim report

                                           • study or budget grade estimates of
                                             capital and operating costs;
                                             profitability analysis

                                           • final report with recommendations
spection agenda, or a checklist detailing
what is to be accomplished, what ques-
tions or issues need to be resolved, and
what information needs to be gathered.
The needs list should be provided to the
facility before the actual site visit to allow
the  facility  personnel to assemble  the
materials needed by the audit team in
advance.

2.  Pre-audit meeting
  The next  step is a pre-audit meeting
with plant personnel. This initial contact
should  include solicitation of plant per-
sonnels' views on the focus and function
of  the  audit.  The  information needs
identified in the previous step should be
discussed. A tour of the facility should be
performed  to familiarize  the audit team
with the operations  performed.  During
this meeting, it is important to establish a
key facility contact.

3.  Data compilation and waste
    stream selection
  Selecting the principal waste streams
or  waste producing  operations for  the
audit provides the audit team with  the
focus for the effort. The criteria used for
waste stream  selection  include waste
                                      composition, quantities, degree of hazard,
                                      method and cost of disposal, perceived
                                      potential for minimization, and compliance
                                      status.
                                        After all  pertinent data  are collected,
                                      they should be assembled in the form of
                                      a written facility description. The descrip-
                                      tion should include facility location and
                                      size, description  of pertinent operations
                                      or processes, and a description  of the
                                      waste  streams  centering  on sources,
                                      generation  rates, and current methods of
                                      management. The report should include
                                      a written justification for selection of a
                                      waste stream(s) for study.

                                      4. Audit inspection
                                        The  audit inspection is  the  ultimate
                                      step in the information gathering process.
                                      The governing objective of this step is to
                                      evolve a fuller understanding of  primary
                                      and secondary causes of waste generation
                                      for the selected waste streams,  and to
                                      cover the items  missed in the pre-audit
                                      phase. The audit inspection must result
                                      in a clear understanding of waste gen-
                                      eration causes. Useful guidelines for this
                                      step include having a detailed inspection
                                      agenda ready in  advance, scheduling the
                                      inspection to coincide with the particular

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 operation  that  is of interest, obtaining
 permission to interview plant personnel
 directly, obtaining  permission to photo-
 graph the facility, observing the "house-
 keeping"  aspects of operation,  and
 assessing  the  level of coordination  of
 environmental activities between various
 departments.

 5.  Generation of WM options
  The objective  of this step is to generate
 a comprehensive set of WM options. It is
 important  at this point to list as large a
 number of options  as possible, including
 WM  measures  currently in place in the
 audited facility. Option generation should
 follow a hierarchy to reflect the environ-
 mental desirability  of  source reduction
 over  recycling,  and of recycling over
 treatment. Options can be generated by
 examining  the technical   literature,
 through discussion with manufacturers
 of equipment or  suppliers of process input
 materials,  and  through the  use of a
 checklist. Table 2  provides  a checklist
 suitable for solvent wastes.

 6.  Options evaluation
  Each of  the options postulated in the
 preceding  step  must undergo a prelimi-
 nary qualitative  evaluation. The objective
 of  this evaluation  is  to weed out the
 measures  that  do  not merit additional
  consideration and to rank the remaining
  measures in the order of their overall
  desirability.  The evaluation should con-
  sider  aspects  such as waste reduction
  effectiveness, extent of current use in the
  facility,  industrial precedent, technical
  soundness, cost, effect on product quality,
  effect on plant operations, implementation
  period,  and implementation  resources
  availability.  It  is recommended that the
  evaluation  process be performed inde-
  pendently by both the audit team and the
  host facility personnel. A rating system
  has been developed to rank the measures
  in a consistent pattern and to provide a
  framework for resolving  the differences
  in opinions.

  7. Selection of options for
     feasibility analysis
    Following the evaluation process  by
  the two  independent groups, the two sets
  of ratings are compared and discussed in
  a joint meeting in order to develop ratings
  which are mutually acceptable. The pro-
  duct of this meeting is a WM options list
  with revised ratings. The final ratings are
  then used as a basis for the selection of
  options  for additional feasibility analysis.
  The number of measures promoted to the
  feasibility evaluation  stage  depends  on
  the time, budget, and resources available
  for such study.
 8.  Analysis of technical and
    economic feasibility
  The specific WM options selected for
 additional evaluation must be analyzed.
 Study-grade (e.g., ±30% accuracy) esti-
 mates for the capital and operating costs
 can be obtained from preliminary vendor
 information or factored estimation tech-
 niques. Once the costs are obtained, the
 analysis is focused on an estimation of
 profitability, based  on conventional
 methods (payback period, internal rate of
 return, or net present value).

 9.  Final report preparation
  As the concluding step of a WM audit,
 a final report should be prepared  to
 summarize all the pertinent data, results,
 and recommendations.

 Results of Waste Minimization
 Audits for Solvent Wastes
  Waste minimization audits were con-
ducted at  two  facilities  generating
solvent-bearing wastes. The following is
 a summary of the  reports prepared  for
each facility.

Facility S-1A/B
  Facility  S-1A/B,  located in Southern
California, is a major aviation,  industrial,
and seaport complex supporting  anti-
Table 2.    Source Reduction Options Checklist for Solvent Wastes
              General Options

Alternate cleaning agents

Alternate paint stripping agents


Equipment cleaning
  Dedication
  Quality control

  Mechanical cleaning

  Inert blanketing

Equipment modification
  Bag filters
  Metal mesh filters
  Clean-in-place systems
Waste handling
  Segregation
  Standardization
  Reuse

  Recycling
  Heat Recovery
                                    Comments

— Possible replacements include steam and alkaline cleaners.

— Possible replacements include caustic, cryogenics, abrasives, and thermal paint stripping
   methods.

— Uncontrolled use of solvent for cleaning can be a major waste generator.
— Reduces the need for equipment cleaning between batches of product.
— Reduces the generation of off-spec batches. Equipment that produces off-spec material must
   be cleaned before it can be reused.
— Use of wipers to remove deposits from tank walls can reduce the need for cleaning with
   solvent. Pipelines can be "pigged" before flushing.
— Prevents the drying of materials inside the equipment.

— Can reduce the need for cleaning or reduce the waste volumes produced.
— Retain less material than cartridge filters. Can be cleaned and reused.
— Can be back-washed during system flush thereby generating no filter waste.
— Often designed to recycle cleaning agent. High pressure spray systems often eliminate the
   need for using solvents to remove heavy deposits.

— Proper handling is crucial to the success of recycling solvent waste.
— Increases the likelihood that a solvent waste can be successfully recycled.
— Increases the amount of recyclable waste thereby improving the economics.
— Dirty solvent can often be reused in less critical cleaning operations or be used as pan of the
   product formulation.
— Requires the use  of a continuous or batch still.
— Many solvents can be used as fuel in industrial boilers/furnaces.

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        Options for Cold Cleaning Tanks

Tank location

Tank lids
  Removable
  Hinged
  Roll type
  Water seal

Tank vents

Parts handling
  Precleaning inspection

  Entrance/exit speed
  Pan drainage
  Rack maintenance

Cleaning efficiency
  Degree of agitation
  Two-step counter-current sequence
  Emulsifiers
  Vapor degreaser


        Options for Vapor Degreasers

Operation
  Heat input
  Cooling water temperature

  Pans spraying
  Overloading
Maintenance
  Leaks
  Water separator
  Stabilizer level
  Cross-contamination
  Sludge removal

  Solvent recovery

Modification
  Freeboard height
  Freeboard chillers
  Silhouette entries
— Tanks near heat sources or drafts can exhibit large evaporative losses.

— Frequent use reduces evaporative losses.
— Seldom used if heavy.
— Often used. Piston effect can cause emissions.
— Best. Disturbs vapor zone least.
— Used with chlorinated solvent. Water quality should be routinely monitored.

— Excessive use increases emissions. Flow rate should be less than SO cfm/ft2.

— Proper handling can extend solvent life and reduce losses.
— Pans should be relatively dry. Excessive water can lead to acid formation when chlorinated
   solvents are used.
— Avoid speeds greater than 11 feet per minute to avoid drag-out of vapor.
— Pans should be properly racked so that solvent drains freely.
— Cracks can drag-out solvent and corrosion can contaminate the solvent.

— The greater the efficiency, the more pans cleaned per volume of solvent.
— Can be increased by installing a pump/jet. a mixer, or an ultrasonic unit.
— Allows a higher degree of spent solvent contamination to be reached.
— Provides additional cleaning action by dissolving grease and soil.
— Can clean at much higher contamination levels than can cold cleaning tanks and provides a
   much better cleaning action.
   If too high, will increase solvent loss to the atmosphere.
   Solvent vapor will not be recovered if too high and undue condensation of moisture from the
   atmosphere will occur if too low.
   Spraying pans above the vapor line bypasses the emission control equipment.
   Overloading coHaspes the vapor zone which causes air to be drawn into the unit. Solvent loss
   occurs as the zone reforms and the air is expelled.


   Cooling coil/steam leaks can introduce excessive water into the unit.
   Failure to routinely purge (remove water) can lead to acid formation.
   Stabilizers are added to chlorinated solvent to prevent acid formation.
   Trace amounts of different solvents can lead to acid formation.
   Routine removal reduces the amount of solvent absorbed by the sludge and the potential for
   acid formation.
   Vapor degreasers can be operated as a still to recover solvent.
   Increased height can reduce solvent vapor loss due to turbulence/drafts.
   Can be used to create a blanket of cold air which suppresses vapor loss.
   Reduce the open area of the unit thereby reducing vapor loss.
 submarine aircraft,  helicopters, and air-
 craft carriers of the Pacific Fleet. Facility
 S-1A operations are mostly performed by
 military  personnel, while facility  S-1B
 operations are performed by civilians.
   There  are over 100 solvent end use
 points in the entire base. Solvent is used
 in many servicing operations, especially
 parts degreasing and paint stripping. Due
 to the  magnitude and diverse  nature of
 the operations performed, four stations
 were selected from the ten initially audited
 for a  detailed  analysis. The  stations
 selected were Station #1 - Cold Cleaning
  Tank, Station #4 - Ball Bearing Cleaning,
  Station  #6  -  Vapor Degreasing,  and
  Station #7 - Epoxy Paint Stripping. These
  stations represent a fair cross-section of
  the types of activities that occur at the
  base.
    For the four stations selected, a total of
  36  source reduction options  were con-
  sidered.  Several  of these options were
  then  selected  for further investigation,
  based on  their  high  future reduction
  index. Additional  information was ob-
  tained from further searches of the avail-
  able  literature  and  from contact with
equipment vendors. The measures evalu-
ated in detail  included: use of a closed
tank and increasing the cleaning efficiency
of Station #1 by increasing the degree of
agitation; increasing the cleaning  effici-
ency of Station #4 by employing a two-
step counter-current cleaning  sequence;
reclaiming solvent from spent 1,1,1-TCE
at Station #6 by using the degreaser as a
still; and continuous filtering of stripper
solution at  Station #7 (see Table  3).
Measures that involved changes in oper-
ating procedures only were not considered
for additional analysis.

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Tab/* 3.   Summary of Source Control Options Investigated for Facility S-1
              Control
   Station     Method
                           Waste Reduction
                       Capital
           (gal/yr)       Cost
Savings     Payback
             Closed
             Tank (d)

             Increased
             Agitation
75(37)       495       $2,910    $ 360      8.1 Years
                                   620 (a)
4
6
7
Counter-
Current
Cleaning
Level
Alarm
Sludge
Removal
50(33)
62(40-50)
50(64)
300
246
364
$ 600
$ 600
$6,820
$ 220
380 (a)
$ 980 (b)
$2,770
2.7 Years
1.6 Years
7 Months
3.0 Years
(a) Assumes no credit for the waste solvent.
(b) Excludes savings due to reduced disposal costs.
(c) Quantity in parentheses represents percent reduction in virgin solvent use.
(d) Modification of the existing tank would not be viable.
Facility S-2

  Facility S-2, located in Southern Cali-
fornia, is a major manufacturer of multi-
layer ceramic capacitors used  primarily
by the telecommunications and military
electronics industries. Production opera-
tions are  performed in two  separate
buildings located within close proximity
to each other. Ceramic materials  are
formulated  in the  Annex Building and
then transferred  to the Main Facility
                where the capacitors are formed. Various
                finishing operations are performed at both
                buildings.
                  The major solvent waste generating
                operations audited at the facility include:
                cleaning of ball mills, slurry transfer pots,
                and slurry application systems with RM-
                513 (a proprietary solvent) and recycled
                1,1,1-Trichloroethane  (TCA); general
                cleaning with isopropyl alcohol (IPA) and
                recycled TCA; and the on-site recovery of
                spent TCA (see Table 4).
  A total of  22 options  were  initially
postulated for the  reduction of solvent-
bearing waste from the audited  opera-
tions. Following discussions with  facility
personnel, seven  of the  options were
selected for further investigation based
on  their  high future  reduction  index.
Additional information was obtained from
further searches of the available literature
and from contact with equipment vendors.
The options evaluated in  further detail
include segregate  and recycle RM-513
based  off-spec  slurry,  segregate, stan-
dardize,  and  recycle cleaning solvents,
segregate and recycle  RM-513 flushing
solvent, convert application system filters
to bag/wire mesh type,  segregate and
recycle  isopropyl  alcohol waste,  and
install secondary recovery system for TCA
primary recovery waste.


Observations and
Recommendations
  The following observations and recom-
mendations were made as the result of
the pilot audits:
  • For one of the  two facilities audited,
     the  availability of the required pro-
     cess documentation was  not satis-
     factory. Experience with these and
     other sites indicated that  the avail-
     ability and quality of the information
     varies significantly. Much informa-
     tion is available, however, from out-
     side sources such  as  vendors,
     chemical suppliers, and literature.
Tab/* 4.   Summary of Solvent Waste Minimization Options Investigated for Facility S-2
Waste Source
Ball Mills and Transfer Pots
Minimization Option
Segregate and recycle RM-513 wastes.
Standardize solvent used and recycle.
Waste Reduction
gallons/year percent
720(a)
2.15O(a)
28.8
86.O
Net Annual
Savings(f)
$6,040
$19,130
Capital
Costs
$25,750
$25,750
Payback
Yearsfgf
4.3
1.3
Slurry Application Systems
General Cleaning With
  Isopropyl Alcohol

TCA Primary Recovery

All Waste Sources Shown
  Above
  Segregate and recycle cleaning waste.             725(c)
  Use bag type filters.                             —
  Use metal mesh type filters.                      —

  Segregate and recycle cleaning waste.           2,350
  Install a secondary recovery system.             2,015(b)

  Use a common batch still for above methods.     5,810
                       96,7
                       90.0(d)
                       lOO.O(e)
         $5.400
         $1,260
         $6,660
$25,750
$23,950
 $9,830
                        SO.Ofd)    $11.650    $25.750


                        73.3       $7.100    $25.750

                        54.3      $30,190    $25.750
 4.8
19.0
 1.5

 2.2
                                3.6

                                0.9
(a) Based on waste volumes before solidification.
(b) Based on the volume of waste shipped off-site for treatment.
(c) See notes (a) and(b) above.
(d) Assumed value.
(e) Filters would be backwashed with the flush solvent so that no additional solvent would be required for cleaning.
(f) Net annual savings is the difference between the actual savings due to reduced raw material and disposal costs and the operating and
   maintenance costs.
(g) Payback period equals the capital cost divided by the annual savings. The payback period does not account for depreciation.

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Pre-audit activities, particularly the
pre-audit site visits, were found to
be extremely important in facilitating
the audit  process. Cooperation by
the plant staff was improved when
the audit  team  spent more time
getting to know the host facility staff
and  how  their organization func-
tioned.
Participation in the options ratings
process is much improved when the
host facility personnel are  required
to independently develop ratings of
each  of the  WM options  under
consideration.
Good operating practices  recom-
mendations must be presented with
their economic dimension  stressed
in order to retain the interest of the
host facility  personnel. Otherwise,
they can be seen as trivial and trite.
This report was prepared by staff of Jacobs Engineering. Pasadena. CA 91101.
Harry Freeman is the EPA Project Officer (see below).
The complete report, entitled "Waste Minimization A udit Report: Case Studies
  of Minimization of Solvent Waste from Parts Cleaning and from Electronic
  Capacitor Manufacturing  Operations," (Order No. PB 87-227 013/AS: Cost:
  $18.95, subject to change) will be available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Officer can be contacted at:
        Hazardous Waste Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Cincinnati,  OH 45268

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