United States
Environmental Protection
Agency
Research and Development
Risk Reduction
Engineering Laboratory
Cincinnati, OH 45268
EPA/600/S-92/061 October 1992
ENVIRONMENTAL
RESEARCH BRIEF
Waste Reduction Activities and Options for a
Fossil Fuel Fired Electrical Generating Station
Kevin Qashlin 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 which is a fossil fuel fired electricity generating
station. A site visit was made in 1990 during which several
opportunities for waste minimization were identified. Wastes
are generated by several activities which are supportive of the
operation of the station. Options identified for waste reduction
included improved management of waste oil, changes in solvent
usage, use of rechargeable batteries, and changes in painting
practices. 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 generation of fossil fuel fired electricity
(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
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with which the facility staff could apply the manual. In some
cases, NJIPs 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 fossil fuel fired electrical generating station.
The facility has been in operation for approximately 30 yr and
during this time has used coal, oil, and natural gas as fuel. The
choice of fuel depends upon economic and environmental
constraints and options. Wastes are generated by several
activities which are supportive of the operation of the station.
This report does not address any issues related to fuel burning
or related to electricity generation.
Manufacturing Process
Conceptually, the manufacturing process at this facility is rela-
tively simple. Fossil fuel is burned to generate heat which is
used to turn liquid water into steam. The steam is used to
power machinery which generates an electrical current. In
order to carry out these operations, other critical support activities
must take place. These activities include equipment mainte-
nance and repair, painting and surface coating, wastewater
treatment, and boiler service.
For this facility, it is instructive to consider more substantively
the various aspects of these support activities.
There is a great deal of machinery in the facility which depends
upon oil-based lubrication. The practice at the facility is to
change the oil periodically. Waste oil of various types results
from this practice. Some of the oil appears in the water treatment
facility as a result of spills, accidental discharges, or leaks into
cooling water. The oil is separated mechanically. Oil represents
the largest waste stream at the facility.
As a function of maintenance and repair, as well as during the
installation of new components, solvent-based degreasing of
metals is a standard practice. Typically, degreasing occurs by
immersion of the parts into a tank of chlorinated solvent followed
by brushing of the part to remove any adhering grease or oil.
The solvent is periodically sent offsite for disposal when it is no
longer works effectively for degreasing.
A power station represents a relatively harsh environment for
exposed metal surfaces. Consequently, frequent painting oc-
curs. At this facility, the coating of choice is solvent-based
paints, usually applied by brushing.
A power station is a large user of water. As a result of such use
there are residuals from water treatment as well as cleaning of
the equipment used in water handling throughout the process.
In one sense, a major product of the facility is hot water and
steam.
Existing Waste Management Activities
The company has already recognized the advantages and
benefits of identifying and implementing waste reduction and
pollution prevention practices. The use of catch basins or spill
pans at the locations of frequent oil spills in order to catch the
oil and facilitate its recovery and reuse, and the acquisition and
use of a drum crusher with capability to capture any oil or other
contents to allow for recovery and reuse illustrate this recogni-
tion on the part of the company.
Current waste management activities include sending waste oil
and oil/water mixtures for offsite disposal at a cost of $0.10/gal
for oil and $0.65/gal for oil-water mixtures. Accompanying this
is a quantity of oily debris such as filter cartridges, contami-
nated soil, and drying agents. This is also sent out for disposal
at various prices depending upon the material in question.
Waste solvent is sent for disposal at a cost of approximately
$1.20/lb. The cost, however, is highly variable depending upon
the frequency of the pick up and the amount of waste present
at the time of the pick up.
The water treatment facility generates about 600 yd3 of bio-
logical sludge, which is sent offsite for disposal at a cost
generally of $200,000/yr. There is potential that application of
the TCLP requirements may result in reclassification of the
material as hazardous. In the event of such a reclassification,
the disposal costs would be expected to increase substantially!
The chemicals and materials used for boiler treatment are
recovered and sent offsite for disposal under the authority of
contracted water treatment specialists. Although the facility
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pays for the service, the pricing does not include a breakdown
of the waste handling costs.
Waste Minimization Opportunities
This particular assessment was a team effort on the part of
company personnel and the NJIT participants. During the as-
sessment process, the following waste streams were targeted:
Oil and oil contaminated materials
Degreasing solvents
Solvents from painting and related activities
Boiler treatment chemicals
Wastewater treatment sludge
Miscellaneous wastes
The waste oil stream is generated primarily from pump mainte-
nance and from the oil/water separator at the wastewater
treatment plant. Approximately 12,000 gal of waste oil is gen-
erated annually. Logical approaches for reducing this volume
include extending the time period between oil changes and
onsite reconditioning and reuse of some of the oil. The sched-
ule for pump maintenance and oil change is based upon the
recommendations of the equipment manufacturers and the
experience of the technical staff. While some lube oil (such as
turbine oil) is filtered to remove solids and reused when possible,
the importance of the pumps to the operation of the facility and
the relatively low cost of oil engenders a reluctance on the part
of the production staff to risk pump failure for the sake of a
marginal reduction in the quantity of waste oil.
In addition, there is a direct correlation between maintenance
activities and the generation of filter cartridges. Generation of
oily debris such as absorbent "diapers", speedy dry, and con-
taminated soil are related to small pump leaks and minor spills
of similar nature.
In order to address these waste sources without adversely
impacting pump performance the following options were identi-
fied. The placement of additional small, regularly emptied catch
basins or pans under pumps and connections with a history of
developing leaks could reduce greatly the amount of cleanup
debris and absorbent generated. The recovered oil can be
added to the waste lubrication oil sent for offsite reclamation
or, if suitable, can be returned to the equipment it came from.
The facility has indicated that equipment maintenance is a
critical concern. A modified approach to oil changes can be
developed which has the potential of protecting the operating
integrity of the equipment while still reducing the volume of oil
used. In situations where equipment is used intermittently,
installation of a time-of-use meter on the equipment with oil
changes being performed after a certain period of operation
should reduce the total volume of oil used and still provide
mechanical protection. Certainly for equipment which is used
continuously, a static- or calendar-driven oil change schedule
could be continued.
For some applications, synthetic lubricating oils have been
found to afford extended times between changes. Reportedly,
such oils have been evaluated at this facility and found not to
extend appreciably the time between oil changes. Additional
consultation with manufacturers of oils and of the equipment
may result in the identification or development of a lubrication
product with the necessary characteristics. It should be re-
membered, however, that such synthetic lubricants may not be
amenable to recovery and reuse as is regular lubricating oil
due to the nature of the formulation.
Oil/water mixtures are currently sent offsite for disposal at a
cost of $0.65/gal. In contrast, waste oil can be sent for recovery
at a cost of about $0.10/gal. It is recommended therefore that
consideration be given to acquiring an oil/water separation
capability such as a centrifuge. Such capability should reduce
waste management expenses and reduce the volume of wastes
sent offsite. The water produced by the separation process can
be sent to the facility's wastewater treatment system.
The mechanical equipment at the facility requires frequent
maintenance and repair in addition to oil changes. Frequently
repair of various machine components requires degreasing of
the affected part prior to the repair procedure. Typically, a
chlorinated solvent is used to carry out the degreasing because
it is fast and effective. A frequent goal of pollution prevention
initiatives is to reduce the level of use of chlorinated solvents
because they present potential risks both to human health and
to the environment. Three possible options would decrease the
use of chlorinated materials:
Use of any solvent for degreasing can be reduced signifi-
cantly by simple manual wiping of the part to remove
gross oil and dirt. In addition to requiring less solvent or
other chemical, such a procedure will result in a lengthen-
ing of the life of the degreasing bath by reducing fouling of
the solution.
Use of newer types of degreasing equipment such as
ultrasonic degreasers can eliminate the need for an or-
ganic solvent by use of a heated caustic solution facilitated
by ultrasound induced energy transfer.
Frequently, substitutions can be made for the chlorinated
solvents. These substitutes may include aliphatic hydro-
carbons, terpenes, N-methyl-2-pyrrolidone and dibasic acid
esters. None of these substitutes will work universally,
however, one or more may be useful for any specific
application.
Where use of chlorinated solvents cannot be avoided, consid-
eration could be given to recovery and reuse of the solvents by
purification through onsite distillation. This would require the
addition of distillation capability and would result in the gen-
eration of a new waste streamstill bottoms. It can be predicted
however, that this stream would be significantly smaller than
the spent degreasing solvent stream.
Another significant solvent-containing waste stream results from
painting and coating activities. Surface protection is a signifi-
cant part of the maintenance activities at the facility. Reduction
of solvent use by switching to water-based paints where perfor-
mance requirements can be achieved is a plausible goal.
Where an acceptable water-based substitute for a solvent-
based coating cannot be readily identified, discussions with
coating manufacturers should be held in order to communicate
the need and request such a product. Such water-based coat-
ings not only reduce the quantity of solvents which evaporate
into the air at the facility, they lessen the need for additional
solvents for area clean-up and equipment cleaning. Where
spray painting technologies are used, a viable option is to
consider use of newer technology equipment, particularly those
using high volume-low pressure approaches.
The wastewater treatment plant at the facility produces sludge
which is disposed of offsite. One waste minimization approach
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involves reducing the organic loading of the wastewater which
goes to the plant, thereby reducing the quantity of sludge
produced. There is a high correlation between the organic
contaminant level in the water sent for treatment and in the
plant. Reduction in the organic loadings will require a careful
study of the sources of contamination entering the wastewater
and development of a plan to reduce the levels of this con-
tamination.
Although not defined as a waste minimization option, dewater-
ing of this waste stream to reduce its volume was also consid-
ered. The sludge currently sent offsite now contains only about
30% solids. The quantity of waste can be reduced by removal
of the water. Two possibilities for this type of water removal are
sludge drying utilizing waste heat from the generation equip-
ment or improved filter press operation.
Corrosive solids, cleaners and descalers are used as boiler
cleaning agents. In many cases, alternate procedures such as
use of a less toxic blast medium in place of the corrosive
cleaning agents may reduce or eliminate the need for the
corrosive material. Additional evaluation of the potential changes
in effectiveness, labor costs, and disposal costs must be per-
formed in order to assess the pollution reduction potential of
such an approach.
The large number of batteries used at the facility, largely for
flashlights, suggests that the use of rechargeable nickel-cad-
mium batteries may be a realistic option. However, the capital
expense for the batteries and chargers may slow adoption. It is
suggested that a controlled experiment using a subset of workers
and flashlights be tried initially in order to determine the mag-
nitude of the savings, both economic and environmental, which
may be obtained. If nickel-cadmium batteries are used, then
when they must be discarded, their disposal should be carefully
coordinated with a recycling/reuse procedure for such products.
It would seem particularly appropriate for an electrical utility to
be involved in such a demonstration with rechargeable batter-
ies.
The type of waste currently generated by the plant, the source
of the waste, the quantity of the waste, and the annual treat-
ment and disposal costs (where known and available) are
given in Table 1.
Table 2 presents the opportunities for pollution prevention
which were identified during the assessment. The type of
waste, the minimization opportunity, and the possible waste
reductions, are presented in the table. When available or esti-
mable, the associated savings, implementation costs and pay-
back times are also given. Savings may include not only
avoidance of costs for waste management, it may also include
credits for raw materials which are recovered or not lost.
Therefore, the total savings may be greater than the present
costs for waste disposal.
It should be noted that the economic savings of the minimization
opportunity, in most cases, result from the need for less raw
material and from reduced present and future costs associated
with waste treatment and disposal. It 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
On the surface, the waste reduction opportunities at this facility
seem relatively free of regulatory implications. However, there
are at least two areas where regulatory concerns have signifi-
cant impact on decision making. In the area of waste oil, it
would seem that this would be an ideal location for onsite
burning of such materials for energy recovery. However con-
cerns about necessary air permit modifications and hazardous
waste status of the oil make it unlikely that the facility would
proceed with the option. Therefore the waste oil will probably
continue to be sent offsite for disposal. Second, a facility such
as this is subjected to another type of regulatory involvement.
Specifically the rate setting board which can penalize the
facility economically for too much down time in electrical gen-
eration. Such possibilities discourage changes such as alter-
native oil change schedules and alternative boiler maintenance
procedures because of great uncertainty about resulting
equipment reliability.
This Research Brief summarizes a part of the work done under
cooperative Agreement No. CR-815165 by the New Jersey
Table 1. Summary of Current Waste Generation
Waste Generated Source of Waste
Waste Oil
Oil changes, spills,
and leaks
Annual Quantity
Generated
12,000 gal
Annual Waste
Management Costs
$1,200
to
7,800
Waste Solvent
Wastewater Treatment
Sludge
Contaminated Water
Parts degreasing
and paint solvent
Organics in wastewater
Boiler cleaning and
conditioning
1,200 Ib
600yd3
100 tons
not annual
every 5-8 yr
1,600
200,000
hidden costs
included in contract
estimate $20,000
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Table 2. Summary of Recommended Waste Minimization Opportunities
Waste Stream
Reduced
Waste Oil
Minimization Opportunity
Expand use of drip pans
Extend period between oil
Annual Waste Reduction
Quantity Percent
50 gal
1200 gal
0.4
1.0
Net
Annual Savings
$50
1300
Implementation Payback
Cost Years *
$100
2000
2
1.5
changes by timing use
Waste Solvent Wipe parts manually
Change to alternative
Ultrasonic degreasers
Wastewater Treatment Reduce organic loading
Sludge to treatment facility
Boiler Cleaning Water Investigate dry cleaning
technology
100 Ib 8.5 100 100
(This option would generate oily rags to be
disposed of or laundered.)
Not necessarily any
but should result in
lower levels of toxicity.
1,200lb 100 1600 5000 3.1
estimate
60yd3
Up to 100 tons, but requires study before
implementation. Solid waste would result.
100
10
1600
20,000
5000
Not known without
detailed survey
of sources
* Savings result from reduced raw material and treatment and disposal costs when implementing each minimization opportunity independently.
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.
ffV.S. GOVERNMENT PRINTING OFFICE: 1994 SSO-4M7/WI5*
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United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
EPA/600/S-92/061
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
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