General Dynamics Eliminates 40 Million Pounds of

I
POLLUTION ENGINEERING
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General Dynamics. a leader i n America’s defense on
land and sea and i n the air. has also become a leader in
protecting those same areas against pollution.
Through an ambitious “Zero Discharge” program,
General Dynamics is seeking to eliminate hazardous
waste from its nine divisions and several subsidiaries
around the country. The company produces defense
weapons, including the F- 16 Fighting Falcon aircraft,
the Trident and SSN 688-Class nuclear submarines,
the M 1 A I Abrams tank, the Tomahawk cruise missile
and the AtlasICentaur launch vehicles. It also owns
commercial businesses which include construction
materials. general aviation and coal mining.
Four years ago. the company’s top management took
the lead o n its own initiative and commissioned an internal task team to examine the structure and function
o f a plan to improve the environment. The objective of
the ”Zero Discharge Program” was to have no Rcsource Conservation and Recovery Act (RCRA) manifested hazardous waste leaving General Dynamics facilities. This was the establishment of General
Dynamics’ Environmental Resources Management
(ERM) program.
“We must take action to eliminate the generation,
discharge and disposal of hazardous materials and to
make better use of our material resources,” said Oliver
C. Boileau, the company’s President i n 1984, in a message to more than 100,000employees. “All employees
of this company, international as well as domestic.
have a responsibility to protect the environment.“
Operating managers responded. The company embarked o n a program so aggressive that today the
results far exceed standards set forth in many U.S. En-
72
vironmcntal Protecti\,c Agency (EPA) regulations.
Nearly 40 niillion Ib of hazardous waste discharge
were eliminated from 1983 to 1988, while sales have
increased from $7.3 billion to $9.35 billion over the
same period. And even though Boileau retired earlier
this year. the program‘s role as a business strategem
was not threatened. receiving renewed sponsorship by
Chairman and Chicf Executive Officer Stanley C
Pace.
Reductiori of Ciu:urdous chemiculs used in opemtions, substitutiori c $ l m hazardous materials, und’
better quuliiy control to reduce production spoilage
are all exxarnp1c.s of octions which reduce the
amount oj huzctrdous wwte requiring disposal.
For the five-year period f r o m 1985 through 1989,
the company’s environmental management program
called for General Dynamics to invest over $36 million
in capital improvcmcnt~.That investment is on schedulc. Meanwhile. anorher 535 niillion is being spent by
General Dynamics custoiners to improve their facilities which the company operates.
As a first step, the company estahlished a corporatewide ERM team. Frank J. Basile Jr. was named Corporate Director-ERM at the St. Louis headquarters. and
an ERM program nianager was named at each division. Within months the “Zcro Discharge” plan was in
place at General Dynamics‘ l‘acilities from Massachusetts t o California.
A corporate policy 2nd procedure was promulgated
t o establish the ERM dircctor‘s and program managers‘ rcsponsibilitics. Key to the success of the program is the recognition that protecting the environment
is everyone’s responsibility. A t the division level, each
prograin manager chairs a n ERM committee with representatives from appropriate functions. Environmental issues are discussed and resolved so that all functions arc aware of their \ignificance to the company‘s
employees, the communitic\ in which General Dynamics does business and t o both existing and future
business opportunities.
“We are not seeking just to reduce hazardous waste.
Our objective is to eliminate it.” Basile said. “Our objective is t o get that word across to all General Dyna m i cs employees.
“We recognized that we were going to generate hazardous waste, but we wanted t o do something about it,”
Basile added. “We could address the matter through a
number ofapproaches. Where we could use a less hazardous material. we did. But there simply are not substitutes for some materials. That’s where we looked for
other solutions.”
As a start, the ERM team initiated the top five longrange objectives to be achieved by the end of 1989.
Zero discharge of all RCRA hazardous waste.
Removal of all polychlorinated biphenyls (PCBs)
which are used as a heat transfer fluid in electrical devices like transformers. capacitors and switchgear.
Removal of all single-walled underground storage
tanks and/or replacement with doubk-wdlled tanks to
prevent undetected leakage.
MAY 1989
I
*
Development o f hazardous waste incineration
projects.
Establishment of‘ an environmental awareness program for all employees and communicate positive
results .
”We decided there had to be a commitment froni
both sides i n this effort.” Basile said of the company’s
pro-environmental stand. “ I t must come from General
Dynamics as a responsible corporate citiz.en and from
our customers, who must recognize and support what
we are trying to accomplish. They have t o work with u s
in our efforts to eliminate hazardous materials i n our
manufacturing processes which result i n hazardous
waste.”
The theory employed by General Dynamics was simple. If you don’t make hazardous waste in the first
place, there will be none to be disposed o f , o r that
could pose a future environmental liability. I f a manufacturing by-product left the plant through any media.
i t was reported and targeted. All waste rcquiring a state
or federal manifest was reported and cliniinatcd
through other than off-site methods.
When General Dynamics initiated the E R M program
in 1984. a baseline was established for the RCRA hazardous waste that was being shipped from the conipany’s facilities for off-site disposal. Immediately. the
ERM team mobilized to eliminate these wastes.
Long term, five-year plans were developed and implemented under the leadership of each division‘s general nianager, and each division budgetcd the necessary capital to carry out those plan\. Four years of
results are now in:
In most cases, the divisions’ perforniirnccs toward
the objectives were better than planned. For example.
in 1985 the goal for reducing hazardous waste was set
at 16.5%. or a reduction from 78.09Y to 73.363 tons.
The end result, however, was a reduction o f 35%. over
twice the goal! In 1986, the actual total discharge was
reduced another 1 1 % t o 15,267 tons and in lYS7 yet
another 6 % to 13,900 tons. Through December 1988,
General Dynamics has reduced hazardous waste discharge corporatewide by approximately 77 c/; percent.
“Our objective is still zero discharge. We are n o t
there yet. and there are still opportunities tor reducing
waste which require development,“ Basile said.
Future plans to reduce RCRA hazardous waste call
for building hazardous waste incinerators at several of
the General Dynamics divisions. With incineration.
the hazardous waste leaving General Dynamics facilities should ultimately be reduced by YO-YS % from the
1984 baseline.
Meanwhile, the ERM team is claiining a large success in its quest t o eliminate electrical device5 that use
PCBs. In 1984, the total number o f PCB devices was
identified as 2,305. By the end of 1988 General Dynamics expects to have eliminated niost o f that equipment from its facilities. Through December 1988. that
total had been reduced 78% to 510. and six o f the nine
divisions have completed the removal o f all PCB devices from their facilities. All units are expected to bc
eliminated by 1990.
Additionally. the objective ot’ locating and replacing
underground single-walled storage tanks with doublewalled tanks or installing leak detection and monitor-
’OLLUTION ENGINEERING
71
ing systems is almost complete.
The program’s success lies in the conscientious accomplishments made by each division along with the
support the company has received from each of its customers, according to Basile. Because there is no corporate funding for any of General Dynamics division’s
environmental projects, each must pay its own way to
fund the projects necessary to achieve the objectives.
“Also, General Dynamics’ customers recognize and
support the company’s objectives at facilities which we
operate for them,” Basile said.
Another aspect of the ERM program emphasizes
staying abreast of new developments. The Corporate
Director-ERM and all the divisions’ ERM Program
Managers meet semi-annually to review progress towards objectives, to discuss new or pending laws and
regulations and their significance to General Dynamics operations and to share problem solving ideas
and results for managing and thus improving the ERM
program.
“There are so many environmental regulations to
keep up with and there is so much overlap among the
regulations,” B a d e said. “Add to that fact that the regulations are continually changing. That’s why ERM
people constantly monitor for new developments.”
74
“When you face head-on the issues of dealing with
reducing hazardous waste, eliminating PCB electrical
equipment and addressing underground storage tanks
on your own initiative, the result is that the potential
for any impact on the environment is minimized and so
are the attendant liabilities,” Basile said.
“Really, it’s remarkable to watch the progress that
we continue to make towards our objectives because
we are doing more than is required by many federal,
state and local regulations. General Dynamics is especially proud of our accomplishments to reduce hazardous waste,” Basile said.
Source reduction, recycling and waste recovery,
wastewater treatment, the use of electrostatic and turbine spraying of water-based paints, incineration and
elimination of overstocking hazardous materials are
some of the processes used to reduce environmental
waste at the divisions.
Reducing the amount of hazardous waste at the
source through process changes is always first priority.
Reduction of hazardous chemicals used in operations,
substitution of less hazardous materials, and better
quality control to reduce production spoilage are all
examples of actions which reduce the amount of hazardous waste requiring disposal. The less hazardous
MAY 1989
waste to be disposed, the less risk of environmental
damage.
“The most significant thing about the program is
that we have management support - at the very top in the Corporate Office and at the divisions,” Basile
said. “We have an excellent program, and we intend to
keep the momentum going. We are doing everything
possible to deal with hazardous waste on-site, within
the source. Therefore, impacts on the environment are
reduced to an absolute minimum.”
That aggressive approach has put General Dynamics’ Pomona (Calif.) Division in the forefront of
the program. Pomona, which builds various tactical
weapons systems, primarily air-defense missiles and
gun systems employing active or semiactive guidance
technologies, has gained national recognition for its
efforts to clean up the environment. The division has
been featured in several publications and a U.S. EPA
sponsored film called “There Is a Better Way.” The
division’s significant accomplishments include:
Reduction of hazardous waste leaving the facility
by 96% from 11,000 tons to under 400 tons;
Elimination of all 19 PCB electrical devices;
Removal of all 28 underground single-walled storage tanks.
“Our success in eliminating hazardous material discharges is a combination of commitment and funding,”
said Denny J. Beroiz, Program Manager-Environmental Resources Management of Pomona. “Our goal has
been to either recycle or eliminate any possible discharges of hazardous materials into the surrounding
Pomona Valley.”
Pomona has instituted technology such as the use of
electrostatic spraying of water-based paints; elimination of overstocking; use of a minimum number of
standard solvents to facilitate recycling; and installation of ion exchange units to remove heavy metals from
waste streams.
Pomona also reduced the allowable industrial water
pollutant discharge by an additional 60% and redesigned products and manufacturing processes to use
water-based solvents, coatings and fluids.
Additional recognition came to the Pomona Division
in August 1988 when Mayor Tom Bradley of Los
Angeles announced a city program to eliminate discharge of hazardous waste and to encourage private industry to follow suit. Pomona was cited by Bradley as
an example of what should be done throughout Southern California to protect the environment.
“We have made an intensive effort to exceed the re-
Herbert E Rogers, left, President and Chief Operating Officer of General Dynamics, and Frank J. Basile, Jr., Corporate Director Environmental Resources Management, discuss the progress of the program in the Corporate Control Room.
POLLUTION ENGINEERING
75
quirements set down by the Environmental Protection
Agency,” Beroiz said. “Aside from the obvious benefits, our proactive response will save the company
money by implementing procedures now which will
probably be required by the EPA in the future.”
Over the last four years, Pomona has made the necessary capital investments to fulfill the corporate objective of achieving zero discharge by the end of this
year. New equipment - including a self-contained
copper plating machine and an air scrubber which captures potentially harmful emissions - was purchased
for the printed circuit board manufacturing line.
The machine produces as a by-product a two foot-bytwo foot solid slab of copper that is two inches thick
and weighs 30 pounds. This is part of a $4 million investment that Pomona made and was one of the subjects of the EPA film. The copper source is the rinse
water and process tank solutions generated from the
manufacturing of printed circuit boards that must be
treated and neutralized prior to discharge to the sewer.
Nearly all the contaminating metals are removed
from the discharge to the sewer and recovered using
ion exchange and electrowinning equipment. The copper slab represents an equivalent of 3 V 2 tons of sludge
that would require landfill disposal under the old manufacturing process. This emergent technology insures
76
that General Dynamics will never again use the land
for disposal purposes.
If the copper plate were in the old sludge form for
disposal, it would have cost $1,200 for disposition.
Now, however, the recovered copper will have a value
of $25-$50/slab. The difference in cost savings of the
new method over the sludge method is estimated at
$130,000 annually.
“We stopped using landfills in 1986 because it was
not an environmentally sound practice,” Beroiz said.
“We were able to do this by reducing our hazardous
waste at the source and recycling or destroying the rest
through approved commercial disposal facilities.”
Meanwhile, all General Dynamics West Coast divisions have developed and coordinated plans for complying with the California Safe Drinking Water and
Toxic Enforcement Act of 1986, otherwise known as
Proposition 65. This law and its implementing regulations dictate that industry may not discharge detectable
levels of certain hazardous chemicals into any source
of drinking water. The list of chemicals which are considered hazardous is published by the state.
In response, some of the components used in the
company’s products have been redesigned, facilities
have been remodeled and health risk materials are no
longer used or are directly extracted from the air ex-
MAY 1989
haust and the wastewater. All extracted materials are
processed on-site for recovery and reuse. These tasks
were all completed within the 20-month compliance
period defined in Proposition 65.
In addition, there have been significant accomplishments at other divisions of General Dynamics, most
notably Fort Worth, which manufactures the F-16, and
Convair, which manufacturers the Tomahawk cruise
missile and aircraft fuselages.
At General Dynamics’ Fort Worth Division, a new
painting system is being used in F-16 fighter aircraft
production. It not only increases productivity but reduces paint use. The system also aids in the division’s
ERM efforts because, since less paint is used, there is
less waste of which to dispose.
The system, called the proportional painter, automatically mixes water, paint base and paint catalyst
while an operator uses it to apply primer coats to F-16
parts in the factory.
Built to Fort Worth’s specifications by a subcontractor, it eliminates the time-consuming and sometimes
messy task of handmixing water-reducible primer in a
pressure pot. In simple terms, the system draws paint
elements from three containers and mixes them in a
manifold and tube as the operator applies paint with a
spray gun.
It replaces the conventional method of mixing the
paint manually several times a day, a task that temporarily halts the painting operation. Since water-reducible primer has a usable life of only about four hours,
unused paint had to be discarded frequently. With the
older method, a significant amount of paint had to be
thrown away. The new system greatly reduces primer
use since the paint is mixed as it is used.
Fort Worth also began using an innovative method of
rejuvenating material-processing chemicals. That can
reduce the amount of hazardous waste derived from
spent chemical baths by as much as 90 percent.
The system involves electrolysis of solutions to remove metals and other contaminants left by the chemical treatment of aircraft parts in production, thus reducing the volume of waste. The concept is being used
to clean a sulfuric acid/sodium dichromate solution
called etchant. Aluminum components of the F-16 vertical and horizontal stabilizers are processed in the
etchant to prepare their surfaces for bonding with composite tail skins.
The etchant is contained in two large dip tanks.
Spent etchant previously had to be removed periodically, producing about 19,000 gal of chemical waste
for disposal by a contract disposal firm off-site. The
new cleaning system and removal of the contaminants
in concentrated form reduces the volume of waste to
about 120 gal/yr which is treated in the on-site wastewater treatment plant. That process precipitates and
recovers the heavy metals which are present, and the
wastewater sludge which follows is nonhazardous.
Bill Rosenthal, the division’s ERM program manager, also pointed out the major success that the division has had in developing markets for all of its waste
materials.
“An employee suggestion recommended we sell our
wastes to someone who could use them as raw materiPOLLUTION ENGINEERING
Meanwhile, all General Dynamics West Coast
divisions have developed and coordinated plans for
complying with the California Safe Drinking Water
and Toxic Enforcement Act of 1986, otherwise
known as Proposition 65.
als,” he said. “Many of our waste streams contain
valuable materials that are of direct use to other industries.”
Fort Worth’s largest liquid waste stream is a spent
caustic chemical milling solution which contains aluminum. It previously required off-site treatment and
land disposal. That waste stream is now being sold as a
valuable feedstock to an aluminum manufacturer for
direct use in its manufacturing process.
Convair Division, meanwhile, is using high-volume,
low pressure (HVLP) turbine air spray equipment to
apply primers and topcoats to aerospace products. The
system is proving to be cost-effective as well as having
less impact on the environment.
The system atomizes the coating with a high volume
of a warm, dry air at 2 to 6 psi, in contrast to a conventional air spray which uses low-volume compressed air
at 35 to 75 psi.
The turbine system greatly reduces the amount of
overspray that ends up on paint racks, spray-booth surfaces or is emitted into the air to be collected by the
spray booth exhaust system. Material cost savings realized by using the special equipment ranges from 35 to
50 percent.
Eighteen of the turbine system units are mounted on
mobile carts for easy maintenance and transportation
from one area to another. Turbine air manifolds have
Cutting fluid splashes on the interface between a Standard Missile structural component and a machine tool bit, which removes metal, at General Dynamics Pomona Division. The sky
blue liquid, which is a 3percent blend of non-hazardous chemical in water, cools and cuts. The water-based material requires
no disposal because it is replenished through additives.
77
been installed in paint booths to deliver turbine air
from the turbine situated outside the booth to a valve/
regulator assembly in the booth. The mobility of the
system is especially valuable for coating some of the
large airliner fuselage assemblies made at Convair,
which cannot be brought into the paint booths.
The Electronics Division funded the construction
and installation of a piece of equipment known as an
ultraviolet oxidation (UVOX) unit, or “volatile organic compound (VOC) blaster.” It captures VOC’s
emitted from paint spraying operations, and has proven
to be up to 99% efficient in the removal of VOC’s in
tests conducted by the San Diego Air Pollution Control
District.
As a result of the effectiveness of control, Electronics Division did not have to change either the type or
the quantity of military specification paints which are
used.
Other examples of hazardous waste reduction projects which have been implemented across the corporation are listed in the Table. The table also demonstrates
another point - that the General Dynamics ERM program is a multi-faceted one. While the top five objectives have focused on hazardous waste reduction, there
also are continuing efforts to reduce air emissions and
wastewater discharges as well.
“As we approach 1989, we will continue to pursue
the reduction of hazardous waste, and at the same time
increase the emphasis on further reductions of air
emissions and wastewater discharges,” Basile said.
General Dynamics expects to continue the reduction
of VOC air emission and the use of chlorinated fluorocarbons, to install additional wastewater treatment capacity and to install hazardous waste incineration capacity, Basile noted.
“Our efforts have been noticed around the country,”
he added. “When we meet people from other companies and other industries, they ask how we’ve done it.
We’ve set the standards by which they are now measuring themselves. We are proud of our accomplishments
PE
and are happy to tell them.”
Table
Examples of hazardous waste reduction projects
:essna Subsidiary
Modifications niade 10 an existing trichloroethylene degreaher at one Wichita. Kansa\. plant have resulted In the elimination of a loss oI 5,000 Ihlwk of trichloroethylene This irichloroeth) lene wa\ being exhausted to the atmosphere. Cessna will realI L an
~ annual cost sa\ Ings o f w e r $100.0001yr as a result o f t h i s prulect.
U,eof;ir.le;ining,”l\cnt(Naptha)
w i t h a l l a > h p o i n t n f I 4 1 Finplaceof,olventswith
Ila*h point, less than 140 F has reduced the hazardoua waste generation at two afthe
Wichit;i KS. plant5 b\ approximately two tons annually at each facility
:onvair Division
’.
Lindhergh Field Warteuater Treatment Facility -This facility. scheduled for startup
i n mbd- 1989. w d l e m p l q alate-of-the-art technologies i n ion exchange and solids
clariltcatm’ In order to reclaim chromium salts from rinses and processing baths
The $5 inillion project i s expected t o pay hack coinpletely in about four years and w i l l
initially >aye Convair more than %500.000lyr The lbcility w i l l treat approximately
2.600 tonslyr 01 liquid wastes and w i l l produce a highly purified sodium dichromate
liquor that IS suitahle ior re-use in house or for sale to other companies Net waste
reduction for the liquids that w i l l be treated is predicted to he 95 t % .
Coolant Recycling -Cutting lluid\ uhed i n machining operations at the Lindbergh
Field Plant have been eifecuvely recycled \ m e 1986. using a combination ofcentrtfugal filtration and pasteurization. Based on I985 levels. coolant recycling operationa
in 19x8 are expected to reduce a 550 tonslyr waste stream to a level of no more than 50
tonslyr Colt saving, for these operations are not available.
Zlectric Boat Division
Machine \hop coolant recycling has been implemented a t a cost of $77.000 and an
annual savings of$17.000 for waste treatment and diapoaal off-site.
!. Photographic pracess chemical recycling equipment i s heing installed at a cost o f
F140.000. with an expected ravings of $22.000 annually from disposal costs and
metal reclamation
Zlectronics Division
I . Volatile organic compound (VOCI emission control equipment was installed at a cost
of $400.000 A n ultraviolet oxidation (UVOX) unit captures VOCs emitted from
paint-spraying operations with a 99% control efficiency. As a result. the division is
both in regulatory compliance and did not have t o change either the type or quantity o f
military specification paints, which are used
Fort Worth Division
I . Spent caustic recycle by aluminum manufacturer. Direct use as raw material in his
proces,. Not “solid uiaste.” 1987 pounds = 3,215.900. This is interim project until
source reduction process regeneration i n place.
2 . On-site contract coolant reclamation. Established needed storage and holding to allow contractor to regenerate spent coolant for direct re-use in machine tools. 1987
pounds = 454.359. This i s interim project until continuous and hatch systems installed to provide in-house capability.
Land Systems Division
I . The key o f Land Systems‘ major waste reduction efforts was top management support. Careful examination of the high waste-producing operations proved especially
producnve. Previous to Environmental Control‘s involvement. zinc. phosphorus and
chrome-spent chemical baths were dumped on a regular maintenance schedule. The
reduction o f this waste stream by reducing the dump schedule resulted in the eltminal i o n o f 186 tons of waste per year. A quality-control-based tank release was established The estimated cost savings are $40.000 per year Waste management methods
also included the reclassification o f the wastewater treatment plant sludge and waste
paint segregation. which resulted in the generation o f a waste paint stream which was
not hazardous. as well as one waste solvent stream which remained hazardous. Control o f rinse water rate also assisted i n reducing the waste streams. This reduction was
accomplished hy the use of flow-limited orifices in the water supply line. The flow
restricters regulated rinse water volumes to a steady. reasonable tlow. The restricters
effectively controlled operator tendency to overflow the system. Additional innovative waste reduction options include ireere vaporization o f the surface treatment waters. This standard ofi-the-shelf technology de-waters the waste stream by attaining
the “triple point” o f water. This evaporates the water. which constitutes 90% of the
volume. This process reduces the 84.000-gallon stream to an estimated ten drums of
dust. This dust is in process o f being analyzed to determine i t s waste characteristics.
I t is expected that the dust w i l l he non-hazardous. Additional waste reduction methods include the substitution of less hazardous materials and streamlining o f processes
to eliminate the use of chemicals, as well ab improved material handling practices.
Pomona Division
I. Water-based cutting fluids-coolants In the machine shop.
Jennifer Kraus, Environmental Resource Manager at General
Dynamics Electronics Division, views the flow controls of the
UVOX (ultaviolet-oxidation) control system. This system monitors and controls VOC air emissions from paint spraying and
solvent cleaning operations. The UVOX has a control efficiency
of 99 percent and is the first control technology of its kind.
78
turnings) cutting oil runoff and rain water mixing in i n underground tank. A n o i l water separator. full introduction of water-soluble machine coolants. removal of the
underground tank and the covering of the chip bin area ($50,000)resolved the waste
stream. By year-end 1986. machine shop cutting lluid waste reduced to one -two
tons o f unusable tramp oils annually and sent fhr recycling or fuel blending.
2 . In-line and centralized CFC solvent recoverylrecycling on-bite.
A l l facilities are equipped with both in-line and hatch processing equipment for the
distillation o f CFC solvents. The investment was over $500.000 and resulted i n
$800.000annual raw material and waste disposition cost avoidance. Still bottoms are
beine incinerated.
3 P a m \hop niodiiicrtimr (ei<itro\tuc. \prn) a p p l ~ n w n \ .nigh-\oh& paint. uateih a d primer. IOU VOC 4 \ c n t \ , all Jr) nodth.. paint d,~t.lIation, proportiiinal ~ t i i l i
e n rnd roodtu
Thc 1984 hn.eliiie of 310 ton\ ut paint , h q ua\tc\ ua, ironi the uatcr-uall ,pr.i\
hootti, and batchc\ ot pa,nt niixcd bui not cwnpletri) u\eJ u i t h i n their four io I i t c
hour u\cIuI liir Coti\zr\iun o i a u ~ t c r - u a l\pra)
l
booth I I under 15.000and prupor
t . w a l pain1 inmker\ uere ~iirlalled LOT S20.0tK) cach The total muc\imcnt u.31
F70.000 P a m rhop pipiiicnt, dnd w l \ e n t u 3 w uere rrJu2eJ to 20 ton\. annuall).
and are nil thermall) dcstroycd ufi.,!tc
4 Ion exchange and high ma\, transfer eIe;tr.iihcni.c.il
rcwver) of heaby metal\
Metal iinishing and c l r i u i l beard mdniilaitur,np operatwna .ire hcing rcdc,igned dild
retrofitted u i t h emergent t e ; h n h g r ‘ ~ lor ~ k t l d t l l ~ol n
i hem) metal%irom rinse u d ten and .heiiilidl p r o x * %baths In\d\tment l e t e l r‘xcr.co\ S3.000.000
MAY 198