&EPA
United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S-92/013 June 1992
ENVIRONMENTAL
RESEARCH BRIEF
Waste Minimization Assessment for a
Manufacturer of Water Analysis Instrumentation
F. William Kirsch and J. Clifford Maginn*
Abstract
The U.S. Environmental Protection Agency (EPA) has funded
a pilot project to assist small- and medium-sized manufacturers
who want to minimize their generation of hazardous waste but
who lack the expertise to do so. Waste Minimization Assess-
ment Centers (WMACS) were established at selected universi-
ties and procedures were adapted from the EPA Waste Minimi-
zation Opportunity Assessment Manual (EPAJ625/7-B8/003, July
1988). The WMAC team at Colorado State University per-
formed an assessment at a plant manufacturing instruments
for water analysis—approximately 50,000 units/yr. Primary op-
erations include production of cabinets and assembly of
instruments. Sheet metal and small metal parts are usually
chemically treated for desired finishes. Cabinet fabrication in-
volves forming sheet metal, drilling, surface preparation, and
painting. Most manufacturing involves assembly, and many of
the electronic and optical components are purchased from
external suppliers. The team's report, detailing findings and
recommendations, indicated that most waste is generated as
spent reagents and rinse water from metal surface finishing,
but greatest savings could be obtained by filtering and pasteur-
izing metal cutting fluid for recycle and separating its organic
and aqueous phases when disposal becomes necessary.
This Research Brief was developed by the principal investiga-
tors and EPA's Risk Reduction Engineering Laboratory, Cincin-
nati, OH, to announce key findings of an ongoing research
project that is fully documented in a separate report of the
same title available from the authors.
Introduction
The amount of hazardous waste generated by industrial plants
has become an increasingly costly problem for manufacturers
University City Science Center, Philadelphia, PA 19104
and an additional stress on the environment. One solution to
the problem of hazardous waste is to reduce or eliminate the
waste at its source.
University City Science Center (Philadelphia, PA) has begun a
pilot project to assist small- and medium-size manufacturers
who want to minimize their formation of hazardous waste but
who lack the in-house expertise to do so. Under agreement
with EPA's Risk Reduction Engineering Laboratory, the Sci-
ence Center has established three WMACs. This assessment
was done by engineering faculty and students at Colorado
State University's (Fort Collins) WMAC.
The waste minimization assessments are done for small- and
medium-size manufacturers at no out-of-pocket cost to the
client. To qualify for the assessment, each client must fall
within Standard Industrial Classification Code 20-39, have gross
annual sales not exceeding $50 million, employ no more than
500 persons, and lack in-house expertise in waste minimiza-
tion. The potential benefits of the pilot project include minimiza-
tion of the amount of waste generated by manufacturers, re-
duced waste treatment and disposal costs for participating
plants, valuable experience for graduate and undergraduate
students who participate in the program, and a cleaner envi-
ronment without more regulations and higher costs for manu-
facturers.
Methodology of Assessments
The waste minimization assessments require several site visits
to each client served. In general, the WMACs follow the proce-
dures outlined in the EPA Waste Minimization Opportunity
Assessment Manual (EPA/625/7-88/003, July 1988). The WMAC
staff locate the sources of hazardous waste in each plant and
identify the current disposal or treatment methods and their
i£3) Printed on Recycled Paper
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associated costs. They then identify and analyze a variety of
ways to reduce or eliminate the waste. Specific measures to
achieve that goal are recommended, and the essential sup-
porting technological and economic information is developed.
Finally, a confidential report which details the WMAC's findings
and recommendations including cost savings, implementation
costs, and payback times is prepared for each client.
Plant Background
The plant produces instruments used for water analysis. The
plant operates 4,394 hr/yr to produce approximately 50,000
units.
Manufacturing Process
The plant produces colorimeters, spectrophotometers, pH
meters, Ion-selective electrodes, t'rtrators, BOD and COD in-
struments and reagents, turbidimeters, controllers and test kits.
Most manufacturing involves assembly with many components
purchased from external suppliers. Other manufacturing opera-
tions are sheet-metal forming, machining, metal surface prepa-
ration, soldering, and painting. Electronic components are wave-
soldered onto prefabricated circuit boards. (Circuit boards are
obtained from outside suppliers).
Metal forming and machining operations result in spent hydrau-
lic oil and spent cutting fluid, both shipped for disposal by
incineration. Spent reagents from steel surface preparation
(alkaline detergent, phosphoric acid descaler, and iron phos-
phate conversion coatings) and aluminum surface preparation
(caustic, suKuric acid, and ferric sulfate) are combined with
rinse water, treated for Ph adjustment by caustic addition, and
sawered as Industrial wastewater.
Spent solvent from degreasing operations is sent to a recycler,
and recovered solvent is purchased for use in the plant. Waste
solvents from a chemical laboratory and waste solvent-based
paints and thinners are disposed of as hazardous waste.
Existing Waste Management Practices
• The plant returns waste solder to the supplier and
sells metal chips and cuttings as scrap.
• A dry booth is used for painting to avoid generation of
contaminated rinse water and reduce generation of
spent solvents.
* An internal drainage system eliminates miscellaneous
discharges to the sewer, and screens placed over
internal drains prevent entry of melted chips and turn-
Ings.
* In the anodizing line, parts are rinsed over a black dye
tank to reduce drag-out to the rinse tank, extending
the life of the rinse water.
Waste Minimization Opportunities
The type of waste currently generated by the plant, the source
of the waste, the quantity of the waste, and the annual man-
agement costs are given in Table 1.
Table 2 shows the opportunities for waste minimization that the
WMAC team recommended for the plant. The type of waste,
the minimization opportunity, the possible waste reduction and
associated savings, and the implementation cost along with the
payback time are given in the table. The quantities of hazard-
ous waste currently generated by the plant and possible waste
reduction depend on the production level of the plant. All
values should be considered in that context.
It should be noted that, in most cases, the economic savings of
the minimization opportunities result from the need for less raw
material and from reduced present and future costs associated
with hazardous waste treatment and disposal. Other savings
not quantifiable by this study include a wide variety of possible
future costs related to changing emissions standards, liability,
and employee health. It should also be noted that the savings
given for each opportunity reflect the savings achievable when
implementing each waste minimization opportunity indepen-
dently and do not reflect duplication of savings that would
result when the opportunities are implemented in a package.
Additional Recommendations
In addition to the opportunities recommended and analyzed by
the WMAC team, two additional measures were considered.
These measures were not completely analyzed because of
insufficient data or minimal savings as indicated below. They
were brought to the plant's attention for future reference, how-
ever, since these approaches to waste reduction may increase
in attractiveness with changing plant conditions.
• Replace solvent-based paint with electrostatic coat-
ing, which might be used on 70% of painted produc-
tion. However, investment cost for such a system
would be high with a long payback, since present cost
for disposal of waste paint and thinner is small.
• Re-establish a cooperative approach to cutting fluid
management. A balance should be struck between
the desire to minimize waste cutting fluid, which pro-
motes recycling, and the need for product quality,
which does not emphasize recycling.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-814903 by the University City
Science Center under the sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma Lou
George.
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Table 1, Summary of Current Waste Generation
Waste Generated
Spent cutting fluid
Spent hydraulic oil
Waste paint and thinner
Spent reagent solutions
Source of Waste
Cutting fluid is discarded when bacteria buildup has become excessive
or viscosity difficult to control. Spent fluid is disposed of by incineration.
Hydraulic oil is filtered and reused. When it can no longer be used, it
is disposed of by incineration.
Paint spray nozzle cleaning operations result in waste paint and thinner.
Steel surface preparation and aluminum anodizing result in spent reagent
Annual
Quantity
Generated
600 gal
450 gal
150 gal
487,500 gal
Annual
Waste
Management
Cost
$2,850
1,100
440
460
and rinse waters
solutions. Spent detergents, descaler, conversion coatings, caustic, ferric
sulfate, and sulfuric add solutions and rinse waters are pH-adjusted and
discharged as industrial wastewater.
Spent solder flux
Spent degreaser solvent
The flux bath is drained when solderability approaches an unacceptable
level. The spent flux is disposed of as hazardous waste.
Spent solvent from degreasing operations is shipped to a recycler.
Recovered solvent is purchased for use in the process.
300 gal
20 gal
700
20
Table 2. Summary of Recommended Waste Minimization Opportunities
Waste Generated
Spent cutting fluid
Minimization Opportunity
Use existing equipment to filter and pasteurize
Annual Waste Reduction
Quantity Percent
300 50
Net
Annual
Savings
$2,910
Implemen-
tation
Cost
$550
Pay-
back
Years
0.2
Spent hydraulic oil
spent cutting fluid for recycling. When disposal is
needed, treat the spent fluid with sulfuric acid.
Neutralize and sewer the resulting aqueous phase
and dispose of the organic phase as hazardous
waste.
Ship the spent hydraulic oil to a recycler rather than
a disposal facility for cost savings.
1,050
•U.S. Government Printing Office: 1992— 648-080/60014
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Environmental Protection Research Information POSTAGE & FEES PAID
Agency Cincinnati, OH 45268 EPA PERMIT NO. G-35
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EPA/600/S-92/013
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