vvEPA
                         United States
                         Environmental Protection
                         Agency
                         Research and Development
                                   Risk Reduction
                                   Engineering Laboratory
                                   Cincinnati, OH 45268
                                   EPA/600/S-92/057   October 1992
ENVIRONMENTAL
RESEARCH   BRIEF
                     Waste Reduction Activities and Options for a
                         Manufacturer of Hardened Steel Gears

                                  Alan Ulbrecht and Daniel J. Watts*
Abstract
The U.S. Environmental Protection Agency (EPA) funded a
project with the New Jersey Department of Environmental
Protection and Energy (NJDEPE) to assist in conducting waste
minimization assessments at 30 small- to medium-sized busi-
nesses in the state of New Jersey. One of the sites selected
was a facility that manufactures hardened steel gears of various
sizes and application. The manufacturing steps include grinding,
cutting, degreasing, and surface finishing. A site visit was
made in 1990 during which several  opportunities for waste
minimization were identified. Options  for pollution prevention
include changes in use of metal working coolants, degreasing
operations, and the rinsing procedures used in the plating
operations. Implementation of the identified waste minimization
opportunities  was not part  of the program. Percent waste
reduction, net annual savings, implementation costs and pay-
back periods were estimated.

This Research Brief was developed by the Principal Investiga-
tors and EPA's Risk Reduction Engineering Laboratory in Cin-
cinnati, OH, to announce key findings of this completed as-
sessment.


Introduction
The environmental issues facing industry today have expanded
considerably  beyond traditional concerns. Wastewater, air
emissions, potential soil and groundwater contamination, solid
waste disposal, and employee health and safety have become
increasingly important concerns. The management and dis-
posal of hazardous substances, including both process-related
wastes and residues from waste treatment, receive significant
attention because of regulation and economics.
* New Jersey Institute of Technology, Newark, NJ 07102
                        As environmental  issues have become  more complex, the
                        strategies for waste management and control have become
                        more systematic and integrated. The positive role of waste
                        minimization and pollution prevention within industrial operations
                        at each stage of  product life is recognized throughout the
                        world. An ideal goal is to manufacture products while generat-
                        ing the least amount of waste possible.

                        The Hazardous Waste Advisement Program (HWAP) of the
                        Division of Hazardous Waste Management, NJDEPE, is pursu-
                        ing the goals of waste minimization awareness and program
                        implementation in the state. HWAP, with  the help of an EPA
                        grant from the Risk Reduction Engineering Laboratory, con-
                        ducted an Assessment of Reduction and Recycling Opportuni-
                        ties for Hazardous Waste (ARROW) project. ARROW was
                        designed to assess  waste minimization  potential across a
                        broad range of New Jersey industries. The project targeted 30
                        sites to perform waste minimization assessments following the
                        approach outlined  in EPA's  Waste Minimization Opportunity
                        Assessment Manual (EPA/625/7-88/003). Under contract to
                        NJDEPE, the Hazardous Substance Management Research
                        Center at the New Jersey Institute of Technology (NJIT) assisted
                        in conducting the assessments. This research brief presents
                        an assessment of the manufacturing of hardened steel gears
                        (1 of the 30 assessments performed) and provides recom-
                        mendations for waste minimization options resulting from the
                        assessment.


                        Methodology of Assessments
                        The assessment process was coordinated by a team of techni-
                        cal  staff from  NJIT with experience in  process operations,
                        basic chemistry, and  environmental concerns and needs. Be-
                        cause the EPA waste minimization manual is designed to be
                        primarily applied by the inhouse staff of the facility, the degree
                        of involvement of the NJIT team varied according to the ease
                                                                             Printed on Recycled Paper

-------
with which the facility staff could apply the manual. In some
cases, NJITs role  was  to  provide  advice. In others,  NJIT
conducted essentially the entire evaluation.

The goal of the project was to encourage participation in the
assessment process by management and staff at the  facility.
To do this, the participants were encouraged to proceed through
the organizational steps outlined in the manual. These steps
can be summarized as follows:

  • Obtaining corporate commitment to a waste minimization
    initiative
  • Organizing  a task force or similar group to carry  out the
    assessment
  • Developing a policy statement regarding waste minimiza-
    tion for issuance by corporate management
  • Establishing tentative waste reduction  goals to be achieved
    by the program
  • Identifying waste-generating sites and processes
  • Conducting a detailed site inspection
  • Developing a list of options which may lead to the waste
    reduction goal
  • Formally  analyzing the feasibility of the various options
  • Measuring the effectiveness of the options and continuing
    the assessment.

Not every facility was able to follow these steps as presented.
In each case, however, the identification  of  waste-generating
sites and processes, detailed site inspections, and development
of options was carried out. Frequently, it was necessary for a
high degree of involvement by  NJIT to accomplish these steps.
Two common reasons for needing outside participation were a
shortage of technical staff within the company and a need to
develop an agenda for technical action before corporate com-
mitment and policy statements could be obtained.

It was not  a  goal of the  ARROW project to  participate in the
feasibility  analysis or implementation steps. However,  NJIT
offered to provide advice for feasibility analysis if requested.

In each case, the NJIT team  made  several site visits to the
facility. Initially,  visits were made to  explain  the EPA  manual
and to encourage the facility through the organizational  stages.
If delays and  complications developed, the team offered assis-
tance in the technical review, inspections, and option develop-
ment.

No sampling  or laboratory analysis was undertaken as part of
these assessments.


Facility  Background
The facility is  a manufacturer of hardened steel gears of  various
sizes  for different types of applications. The facility purchases
steel  and  through grinding,  cutting, and metal working forms
the parts into the desired shape. Subsequently, the surface  is
treated to provide the expected level of  hardening and wear
resistance.

The facility is located in an urban area and employs about 50
people.


Manufacturing Processes
The production of the hardened steel gears  is  a multi-step
process which  involves  a combination of mechanical metal
working processes  and a series of  surface modifications  in
which chemical  usage is required.
The first step in the production process requires the shaping of
the raw steel into gears of the desired size and configuration.
The shaping is accomplished by appropriate combinations of
cutting,  grinding, and  metal  working.  These  steps  typically
require the use of metal working coolants to facilitate process-
ing.

The next step is degreasing,  required in order to remove any
material on the surface of the  gear that might interfere with the
metal finishing. Degreasing is  accomplished by first dipping the
gear  into a vapor  degreasing  tank  containing 1,1,1-
trichloroethane, drip draining the part over this tank, then dipping
the part into  a hot  alkaline  cleaner using periodic reverse
electrical current for final grease removal. An additional  afca-
line descaler  with periodic reverse  current is  then  used to
complete the cleaning process and any excess of the solution
is rinsed from the part using a hose over the tank.

The  next  step involves plating of  the  degreased gears with
copper using a copper cyanide bath at  150°F. The purpose of
the plating is to protect the surface from unwanted effects in
the final steps of the manufacturing process.

When necessary, the parts are dipped into black oxide for rust
resistance. This is followed by heat treatment which  includes
carburizing, hardening, and nrtriding.

Following  the heat treatment,  the excess copper is deplated in
a sodium cyanide solution.


Existing Waste Management Activities
The   manufacturing  process generates three major waste
streams—the  metal working coolants, the degreasing system
residues, and the rinses from  the plating operations.

The  metal working coolants  are critical to successful metal
working by providing both lubrication and cooling of the metal
being worked and the tools being used. Individual metal work-
ing processes have been established using particular cooling
fluids, therefore there are several different types of coolants in
use at the facility. The coolant is typically an oil-water mixture.
The facility generates about 800 gal of  waste  coolants  each
week that are sent for disposal offsite. The total waste volume
for lubricants and coolants is 40,000 gal.

The residues from degreasing consist of both chlorinated sol-
vents and aqueous residues. The aqueous residues come from
alkaline degreasing steps and  are pH adjusted prior to disposal.
The organic and aqueous phases are separated before being
sent offsite for disposal. There remain traces of halogenated
solvent in the aqueous waste.  About  7000 Ib of 1,1,1-
trtchtoroethane are sent offsite for disposal each year. It is
estimated that approximately another  3000 Ib are lost  by
evaporation.  Approximately 700 gal of  aqueous waste are
generated each year.

The rinses from the plating operation include both copper and
cyanide constituents. The annual flow of this waste stream is
about 5.5  million gal and is sent to the POTW for disposal. The
waste from the deplating step is sent offsite for disposal. The
annual volume of this waste stream is about 2000 gal.


Waste Minimization Opportunities
The  type  of waste  currently generated  by  the  facility, the
source of  the waste,  the quantity of the waste and the annual
treatment  and disposal costs are given in Table 1.

-------
Table 2 shows the opportunities for waste minimization recom-
mended for the facility. The type of waste, the minimization
opportunity, the possible waste reduction and associated sav-
ings, and the implementation cost along with the payback time
are given in the table. The quantities of waste currently gener-
ated at the facility and possible waste reduction depend on the
level of activity of the facility. All values should be considered
in that context.

It should be noted that the economic savings of the minimization
opportunity, in most cases, results from the need for less raw
material and from reduced present and future costs associated
with waste treatment and disposal, ft should also be noted that
the savings  given for  each opportunity reflect the  savings
achievable when implementing each waste minimization op-
portunity independently and do not reflect duplication of savings
that would  result when the opportunities are implemented in a
package. Also,  no equipment depreciation is factored into the
calculations.


Regulatory Implications
There  do  not seem to be  significant  regulatory implications
which would hamper pollution prevention initiatives at this facil-
ity. However,  international  agreements addressing ozone
                                    depletion and global warming may further inhibit the  use of
                                    1,1,1-trichloroethane.  Also,  1,1,1-trichtoroethane is 1  of  17
                                    chemicals which EPA has targeted under a voluntary program
                                    with industry (the 33/50 Industrial Toxics Program) to  reduce
                                    releases to the environment. This program may lead to reduced
                                    use of solvent. If  additional regulations concerning use and
                                    disposal of halogenated degreasers and metal plating residues
                                    become effective, pollution prevention changes at this type of
                                    facility will become even more important.

                                    This Research Brief summarizes a part of the work done under
                                    cooperative  Agreement No. CR-815165 by the  New  Jersey
                                    Institute of  Technology under  the sponsorship  of the  New
                                    Jersey Department of Environmental Protection  and Energy
                                    and the U.S. Environmental Protection Agency. The EPA Project
                                    Officer was Mary Ann Curran. She can be reached at:

                                            Pollution Prevention Research Branch
                                            Risk Reduction Engineering Laboratory
                                            U.S. Environmental Protection Agency
                                            Cincinnati, OH 45268
                                    * Mention of trade names or commercial products does not constitute endorsement
                                     or recommendation for use.
  Table 1.  Summary of Current Waste Generation
  Waste Generated
Source of Waste
Annual Quantity
  Generated
  Annual Waste
Management Costs
  Metal Working Fluid


  1,1,1-Trichloroethane

  Aqueous Waste

  1,1,1-Trichloroetharte
   (air emissions)

  Aqueous Waste

  Aqueous Waste
Lubricant and coolant from
gear shaping operations

Degreasing operations

Degreasing operations

Degreasing operations


Rinses from plating operations

Copper deflating operation
  40,000 gal


  7,000 Ib

  700 gal

  3,000 Ib


  5,500,000 gal

  2000 gal
     $40,000


     3,200

     1,200

     (no direct costs)


     1,700

     7,000
                                                                        •&U.S. GOVERNMENT PRINTING OFFICE: 1994 - 550-067/80179

-------
Table 2.  Summary of Recommended Waste Minimization Opportunities
Waste Stream
Reduced
Minimization Opportunity
Annual Waste Reduction
Quantity        Percent
     Net      Implementation  Payback
Annual Savings      Cost       Years *
Metal Working Fluid
                                       24,000 gal
                 60
    $4000           $0          immed.
 (The savings come from the difference
 in treatment costs from a mobile fluid
 recovery unit and from savings in
 the purchase of new fluid.)
1,1,1-Trichloroethane
                                        7,0001 b
                  100
                              17,000
                     Change practices to use a
                     single type of metal working
                     fluid throughout the facility.
                     This will permit the use of a
                     fluid reconditioning procedure to
                     facilitate the reuse of the material.
                     Such reuse will save on disposal
                     costs and material replacement costs,
                     but will incur some processing costs.

                     Explore possibility ofdegreasing
                     using only the alkaline decreasing
                     baths. If solvent degreasing is
                     still required, evaluate use of
                     non-halogenated alternatives such as
                     a terpene based material.  If alternative
                     solvent is required, then savings will
                     be reduced.

                     If the vapor degreasing can be eliminated
                     there will be additional savings from
                     solvent losses to the atmosphere that will
                     no longer occur. Alternative technologies,
                     such as ultrasonics, should be explored.

Aqueous Rinse Waters Install new rinsing procedures, includ-
                     ing counter-flow rinses, and reuse of
                     highest concentration rinse water as
                     make-up water for the plating bath.

* Savings result from reduced raw material and treatment and disposal costs when implementing each minimization opportunity independently.
                                immed.
                                                             3,000 Ib
                                                        100
                                                             5,390,000 gal     98
                                                                     2,000
                                                                     1,650
                                             3,000
                                                          immed.
                                1.8
  United States
  Environmental Protection Agency
  Center for Environmental Research Information
  Cincinnati, OH 45268

  Official Business
  Penalty for Private Use
  $300
                                                                                  BULK RATE
                                                                            POSTAGE & FEES PAID
                                                                                      EPA
                                                                               PERMIT No. G-35
  EPA/600/S-92/057

-------