United States Center for Environmental Office of Solid Waste
Environmental Protection Research Information and Emergency Respon
Agency
technology Transfer ~March'l988 gERI-88~6i
Solvent Waste Reduction
Alternatives Seminar
Speaker Papers
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Session I
Regulatory Issues
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Land and Liquid Disposal Bans
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LAND DISPOSAL RESTRICTIONS SUMMARY
VOLUME 1
SOLVENTS AND DIOXINS
Submitted to:
Office of Solid Waste
U.S. Environmental Protection Agency
Washington, DC
May 1987
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CONTENTS
Page
1. Introduction 1
2. Treatment Standards (Section 268.40) 7
How Are the Treatment Standards Established? 7
What Is the Best Demonstrated Available 8
Technology (BOAT)?
Setting the Treatment Standards 10
What Is the TCLP? 10
3. Variances and Extensions 11
Variance from the Treatment Standard (Section 268.44) 11
Two-Year National Capacity Variance (Section 268.30) 12
Case-by-Case Extensions (Section 268.5) 13
"No Migration" Petitions (Section 268.6) 15
Rulemaking Procedures 15
4. Treatment in Surface Impoundment Exemption 17
(Section 268.4)
5. Prohibition on Dilution (Section 268.3) 19
6. Storage Prohibition (Section 268.50) 21
7. Permit Program 25
Interim Status Facilities 25
Permitted Facilities (Section 270.42) 25
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CONTENTS (continued)
8. Testing and Recordkeeping (Section 268.7) 27
Generator Responsibilities 27
Treatment Facility Responsibilities 28
Land Disposal Facility Responsibilities 29
9. Treatment Standards for Solvents (Section 268.41) 31
What Solvent Wastes Are Covered Under the F001-F005 31
Listing? (Section 268.31)
Basis for the Solvent Treatment Standards 31
Effective Date of Solvent Land Disposal ' 32
Restrictions (Section 268.30)
10. Treatment Standards for Dioxins (Section 268.41) 35
Effective Date of Dioxin Land Disposal 35
Restrictions (Section 268.31)
Appendix A Information Requirements for a Petition
for a Variance From the Treatment Standard
Appendix B Information Requirements for a Petition
for a Case-by-Case Extension
Appendix C Information Requirements for a Petition
for a "No Migration" Exemption
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1. INTRODUCTION
The Hazardous and Solid Waste Amendments (HSWA) to the
Resource Conservation and Recovery Act (RCRA) were enacted on
November 8, 1984. Among other things, these far-reaching
amendments require EPA to evaluate all hazardous wastes
according to a strict schedule to determine whether land
disposal of these wastes is protective of human health and the
environment. For wastes that are restricted from land
disposal, the amendments require EPA to set levels or methods
of treatment which substantially diminish a waste's toxicity or
reduce the likelihood that a waste's hazardous constituents
will migrate. Beyond specified dates, restricted wastes which
do not meet the treatment standards (or are otherwise exempt as
discussed in this booklet) are prohibited from land disposal
(see Table 1). According to HSWA, if EPA fails to set
treatment standards for a particular waste by specified
deadlines, that waste is automatically prohibited from land
disposal. These so-called "hammer provisions" provide the
impetus for EPA to keep to the strict schedule.
On November 7, 1986, EPA promulgated the first phase of the
land disposal restrictions. In the November 7, 1986 final
rule, EPA established the framework for implementing the land
disposal restrictions program. EPA also established specific
treatment standards and effective dates for the first category
of wastes subject to the restrictions, F001-F005 spent solvent
wastes, and F020-F023 and F026-F028 dioxin-containing wastes.
This booklet summarizes the November 7, 1986 rulemaking and
describes the key regulatory requirements pertaining to
treatment standards, variances, and extensions. The booklet
also outlines the new responsibilities of generators, treatment
facilities, and disposal facilities under the rule. Finally,
it provides an overview of the specific treatment standards
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TABLE 1
SCHEDULE FOR LAND DISPOSAL PROHIBITIONS
November 8, 1986
July 8, 1987
August 8, 1988
November 8, 1988
June 8, 1989
May 8, 1990
Within 6 months of
listing or identification
(these wastes are not subject
to the automatic land disposal
prohibition)
Dioxin-containing wastes
(F020, F021, F022, F023,
F026, F027, F028)
Spent solvents (F001, F002,
F003, F004, F005)
California list wastes
(Liquid hazardous wastes
containing: free cyanides,
PCBs, and certain metals at
or above specified
concentration levels, and
those liquid hazardous wastes
having a pH of less than or
equal to 2.0. Also, both
liquid and non-liquid
hazardous wastes containing
halogenated organic compounds
at or above specified
concentration levels.)
At least one-third of all
listed hazardous wastes
Wastes disposed of in
injection wells
Contaminated soil and debris
from CERCLA Section 104 or
106 response actions and RCRA
corrective actions
At least two-thirds of all
listed hazardous wastes
All remaining listed
hazardous wastes
All characteristic hazardous
wastes
Newly listed wastes
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for solvent- and dioxin-containing wastes, the first wastes
that EPA has evaluated for the land disposal restrictions. The
booklet is geared to individuals who are familiar with EPA's
hazardous waste regulatory program. While it presents a
summary of the land disposal restrictions program, it is not
intended to be a comprehensive review of all regulatory issues
associated with the November 7 rulemaking. For further
information, contact the RCRA/Superfund Hotline at (800)
424-9346 (toll free) or (202) 382-3000 in the Washington, D.C.
metropolitan area.
In the final rule, EPA defined land disposal to include,
but not be limited to, any placement of hazardous waste in:
Landfills.
Surface impoundments.
Waste piles.
Injection wells.
Land treatment facilities.
Salt domes or salt bed formations.
Underground mines or caves.
Concrete vaults or bunkers.
The land disposal restrictions rule covers hazardous wastes
placed in land disposal units after the effective dates of the
prohibitions. Wastes disposed of before November 7, 1986 do
not have to be removed from land disposal for treatment.
However, if wastes are removed from land disposal, the wastes
must meet the applicable treatment standards before subsequent
new placement in or on the land, or they must be the subject of
a variance or extension as discussed in this booklet.
Contaminated soil and debris from CERCLA Section 104 and 106
response actions and RCRA corrective actions are not subject to
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the land disposal restrictions rule until November 8, 1988. In
addition, wastes disposed of in underground injection wells are
not subject to the land disposal restrictions until August 8,
1988.
Wastes which are placed into storage prior to the effective
date are not subject to the restrictions on storage. However,
once taken out of storage, these wastes must meet the
applicable treatment standards prior to land disposal, or they
must be the subject of a variance or extension as discussed in
this booklet.
Wastes may be treated in surface impoundments that meet
minimum technological requirements provided that (among other
things discussed in this booklet) treatment residuals which do
not meet the treatment standards are removed within one year of
placement of the waste in the impoundment.
Both interim status and permitted facilities are subject to
the land disposal restrictions rule (these restrictions
supersede 40 CFR 270.4(a) which currently provides that
compliance with a RCRA permit constitutes compliance with
Subtitle C). However, small quantity generators of less than
100 kg/month of hazardous waste (or less than 1 kg/month of
acute hazardous waste) are not subject to the restrictions.
The November 7, 1986, final rule outlines the Agency's
approach to implementing the congressionally mandated
restrictions on land disposal of hazardous waste. The rule
includes:
Procedures for setting treatment standards.
Procedures for obtaining variances from the treatment
standards.
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Procedures for granting nationwide variances from the
effective dates of the land disposal restrictions due to
insufficient alternative treatment capacity.
Procedures for obtaining extensions to the effective
dates of the land disposal restrictions on a
case-by-case basis.
Procedures for petitioning to obtain a variance from the
land disposal restrictions based on a finding that there
will be no migration of hazardous constituents from the
disposal unit or injection zone for as long as the
wastes remain hazardous.
Provisions for allowing restricted wastes to be treated
in surface impoundments.
Provisions for prohibiting dilution as a substitute for
adequate treatment to achieve the treatment standards.
Provisions for prohibiting the storage of restricted
hazardous wastes.
Provisions for modifying permits.
Requirements for testing and recordkeeping.
« Specific treatment standards for certain dioxin- and
spent solvent-containing wastes.
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2. TREATMENT STANDARDS (SECTION 268.40)
HSWA prohibits land disposal of restricted wastes unless
EPA determines that continued land disposal is protective of
human health and the environment, or unless the applicable
treatment standards have been met. HSWA requires EPA to set
levels or methods of treatment which substantially diminish the
toxicity of a waste or substantially reduce the likelihood that
hazardous constituents will migrate from a waste. These levels
or methods, referred to as treatment standards, must minimize
short- and long-term threats to human health and the
environment. After the effective dates of the prohibitions,
hazardous wastes that do not comply with the treatment
standards are prohibited from being placed in land disposal
units unless:
EPA has approved a petition demonstrating that hazardous
constituents will not migrate from the land disposal
unit for as long as the wastes remain hazardous.
EPA has granted an extension to the effective date of
the prohibition.
How Are the Treatment Standards Established?
To establish treatment standards, EPA identifies wastes
with similar characteristics (i.e., similar physical and
chemical properties). EPA then categori.zes these similar
wastes into broad "waste treatability groups" and subgroups.
The treatability groups take into account differences in the
types and effectiveness of treatment for those particular
wastes. Treatability groups may be formed by grouping wastes
by industries or manufacturing processes which generate wastes
with similar treatability characteristics. EPA then evaluates
identified technologies used to treat the wastes to determine
the best demonstrated available technology (BOAT) for each
waste treatability group.
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What Is the Best Demonstrated Available Technology (BOAT)?
BOAT is the best available method of treatment demonstrated
to be achievable for each waste treatability group. To
establish BOAT for a particular waste treatability group, EPA
first collects and analyzes data on existing treatment
technologies for that waste group that are demonstrated by
full-scale operation. EPA will not consider pilot- and
bench-scale operations in identifying "demonstrated" treatment
technologies.
Once EPA has identified "demonstrated" technologies, the
Agency then determines whether these technologies may be
considered "available," as based on three criteria:
The technology must be commercially available.
The technology must present less risk to human health
and the environment than land disposal of the untreated
waste.
The technology must provide substantial treatment.
Technologies considered in setting BDAT must be found to be
commercially available (i.e., either the technology itself, or
the services of the technology, may be purchased). A
proprietary or patented treatment technology must be able to be
purchased from the proprietor. If it cannot be purchased, the
.technology is considered unavailable and the treatment standard
will be based on the next best technology that is available.
EPA then compares the risks to human health and the
environment associated with treatment of the wastes by the
demonstrated technologies to the risks associated with the land
disposal of untreated wastes. Based on this comparative risk
assessment, those treatment technologies that present greater
risks than land disposal of the untreated wastes will be
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considered unavailable, and will be excluded as a basis for
establishing treatment standards.
If all demonstrated treatment technologies present greater
risks than land disposal for a particular waste, EPA will not
set a treatment standard for that waste. Therefore, the
restricted waste will be prohibited from land disposal (unless
it is the subject of an approved "no migration" petition) until
a new or improved technology emerges that does not pose a
greater risk than land disposal.
EPA will not consider treatment technologies that are
prohibited under RCRA Section 3004(n) because of the potential
for air emissions of hazardous constituents as available for
purposes of establishing treatment standards.
Also, to be considered an available technology, the
technology must provide substantial treatment, that is, it must
substantially diminish the toxicity of the waste or reduce the
likelihood of migration of the waste's hazardous constituents.
This excludes technologies that would provide treatment only
for the sake of treatment without providing substantial
reduction in risk to human health and the environment.
Once the demonstrated available treatment technologies are
identified, EPA then evaluates performance data on these
technologies to determine if the data are representative of
well-designed and well-operated systems. Only data from
well-designed and well-operated systems will be considered in
setting BOAT. These performance data are then analyzed to
determine the best demonstrated available technology.
When treatment data are available for several different
technologies, EPA is using a statistical method known as
analysis of 'variance to determine the level of performance that
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represents BOAT. EPA is also using a process variability
factor in setting BDAT which takes into account normal
variability in well-designed and well-operated treatment
processes.
Setting the Treatment Standards
Once BDAT is identified, EPA then establishes the treatment
standards as either a specific technology (or group of
technologies) or as a performance level (i.e., the
concentration level of hazardous constituents in a waste or
extract of the waste that is representative of treatment by
BDAT; for the November 7, 1986 rule covering solvents and
dioxins, this is expressed as a concentration level of
hazardous constituents in an extract of the waste developed by
using the Toxicity Characteristic Leaching Procedure [TCLP]).
Wherever possible, EPA will attempt to set concentration-based
performance standards since they will provide the most
flexibility to the regulated community. Treatment technologies
that are not used in setting treatment standards may still be
used to comply with treatment standards expressed as
performance levels.
What Is the TCLP?
The TCLP is an analytical method used to determine whether
the concentrations of hazardous constituents in a waste extract
or an extract of the treatment residual meet the applicable
treatment standards. EPA promulgated the TCLP for use only in
the solvents and dioxins final rule, and only when treatment
standards are expressed as concentration levels of hazardous
constituents in an extract. EPA may revise the TCLP at some
future date based on public comments received on the June 13,
1986 Organic Toxicity Characteristic proposed rule (51 FR
21648) .
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3. VARIANCES AND EXTENSIONS
Under certain conditions, EPA may grant a variance from the
treatment standard, an extension to the effective date of the
land disposal prohibition, or an exemption from the prohibition
for a specific waste at a specific site. In the November 7,
1986 rulemaking, EPA established four types of variances and
extensions:
Variance from the treatment standard.
Two-year national capacity variance.
Case-by-case extension.
"No migration" petition.
Variance from the Treatment Standard (Section 268.44)
EPA established the variance from the treatment standard to
account for wastes that are significantly different from the
wastes evaluated by EPA in setting treatment standards and,
therefore, cannot be treated to meet the applicable treatment
standard; for example, exotic wastes, wastes formed by
inadvertent mixing, and wastes that require the use of
technologies different from those used to set the treatment
standard. If a petitioner can successfully demonstrate that a
waste is significantly different from the wastes in its
treatability group such that it cannot meet the treatment
standard, EPA will grant a variance from the treatment standard
for that particular waste. In granting a variance, EPA will
establish a new treatability group for that waste (and all
similar wastes), and set a new treatment standard.
For EPA to grant a variance, the petitioner must not only
successfully demonstrate that the waste is significantly
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different from the wastes evaluated by EPA in setting the
treatment standards, but also demonstrate that the waste cannot
meet the treatment standard. The petitioner must show (by
actual treatment attempts that fail, or by extensive analyses
of the waste) that treatment of the waste by well-designed and
well-operated technologies is unsuccessful in meeting the
specified levels, or that the waste cannot be treated by the
specified technology.
Anyone submitting a petition for a variance from the
treatment standard must certify that all information in the
petition (see Appendix A) is true, accurate, and complete. In
addition, they must comply with all applicable hazardous waste
management regulations during the petition evaluation process.
In considering variance petitions, EPA first will compare
the physical and chemical characteristics of the petitioner's
waste with the physical and chemical characteristics of the
wastes evaluated by the Agency in setting the treatment
standard. This comparison will enable EPA to reexamine its
treatment standard for the waste. EPA will then determine
whether the petitioner's treatment system (if any) is well
designed and well operated, and whether the system reflects
treatment by BOAT (although the restricted wastes are not
required to be treated by BDAT).
Two-Year National Capacity Variance (Section 268.30)
Certain wastes may continue to be land disposed without
treatment for up to two years past the statutory effective
dates of the restrictions rule if EPA determines that adequate
treatment capacity is not available on a nationwide basis. In
determining the need for a national capacity variance, EPA will
consider, on a nationwide basis, both the capacity of
alternative treatment technologies and the quantity of
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restricted waste generated. If sufficient waste treatment
capacity is available, the restriction on land disposal of that
waste goes into effect on the statutory deadline. If there is
a significant shortage of national capacity to treat all the
restricted waste, EPA may set an alternative effective date
based on the earliest date on which adequate treatment capacity
becomes available.
In determining available capacity, EPA will consider both
permitted and interim status on-line facilities. EPA will also
consider planned facilities and capacity extensions that will
be on-line by the effective date of a land disposal
prohibition. On-line facilities will include on-site and
off-site facilities, as well as stationary and mobile
facilities. EPA will not consider underground injection in its
capacity determinations until the Agency has determined whether
such injection is fully protective of human health and the
environment.
EPA will compare available treatment capacity nationwide to
the quantities of the restricted waste generated annually
nationwide. Available capacity will include:
Commercially available capacity.
Private facility capacity which cap be used to manage
additional waste generated by that facility.
Private facility capacity which can be used to manage
wastes generated by other facilities (i.e., can act as a
commercial facility).
Case-by-Case Extensions (Section 268.5)
In cases where alternative treatment or disposal capacity
cannot reasonably be made available by the effective date of
the land disposal prohibitions, interested parties may petition
EPA for an extension of the effective date on a case-by-case
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basis. EPA may grant a case-by-case extension of up to one
year. This extension is renewable only once.
To be considered for a case-by-case extension, a petitioner
must demonstrate a good faith effort to locate and contract
with hazardous waste treatment, recovery, or disposal
facilities nationwide to manage the waste. A petitioner must
also demonstrate that he has entered into a binding contract to
construct or otherwise provide adequate treatment, recovery,
disposal capacity sufficient to manage the entire volume of
wastes. In addition, a petitioner must demonstrate that, due
to circumstances beyond his control, alternative treatment,
recovery, or disposal capacity cannot reasonably be made
available by the effective date.
Anyone submitting a petition for a case-by-case extension
must certify that all information in the petition (see Appendix
B) is true, accurate, and complete. In addition, they must
comply with all applicable hazardous waste management
regulations during the petition evaluation process.
If wastes that receive an extension to the effective date
(either a 2-year national variance or a case-by-case extension)
are to be placed in or on the land, then they must be placed in
a facility that is in compliance with the minimum technological
requirements. These requirements, including a double liner,
leachate collection system, and ground-water monitoring system,
apply to new units, replacement units, or lateral expansions of
existing landfills or surface impoundments at existing
facilities. Wastes receiving an extension may also be place'd
in such facilities that meet other alternative operating
practices, design features, or siting characteristics
determined by the EPA Administrator to be equally protective of
human health and the environment.
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"No Migration" Petitions (Section 268.6)
EPA will consider allowing land disposal of restricted
wastes if a petitioner can demonstrate, to a reasonable degree
of certainty, that such disposal will not allow migration of
hazardous constituents from the disposal unit or injection zone
for as long as the wastes remain hazardous. In general, a
successful "no migration" petition (see Appendix C for petition
requirements) will allow only land disposal of a specific waste
at a specific unit.
EPA believes that there will be very few instances when "no
migration" demonstrations can be successfully made. However,
candidates for a successful petition include cases where wastes
containing relatively immobile hazardous constituents are
placed in monofills located in arid climates with no
ground-water recharge. Other candidates for "no migration"
petitions are cases where a small amount of compatible waste is
placed in a massive and stable geological formation such as a
salt dome.
Rulemaking Procedures
All variances and extensions are rulemaking procedures.
Variances f.rom the treatment standard, case-by-case extensions,
and "no migration" exemptions are petition processes (the
two-year national capacity variance is solely an EPA
determination). EPA will publish its tentative determination
on a petition in the Federal Register. After a 30-day comment
period, EPA will publish its final decision in the Federal
Register.
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4. TREATMENT IN SURFACE IMPOUNDMENT EXEMPTION (SECTION 268.4)
EPA will allow hazardous wastes to be treated in surface
impoundments under the following conditions:
Treatment residuals not meeting the treatment standards
can remain in a surface impoundment for up to one year.
Beyond that time period, the treatment residuals that do
not meet the treatment standards must be removed and
treated to meet the treatment standards before being
disposed, and may not be placed into another surface
impoundment (treatment residuals that do meet the
treatment standards may remain in the surface
impoundment). In cases where the volume of liquid
wastes annually flowing through an impoundment (or
series of impoundments) is greater than the capacity of
the impoundment, this flow-through may constitute annual
removal of the supernatant for the purposes of this
requirement (this will not, however, constitute removal
of any sludge residues requiring annual removal).
The surface impoundment must meet minimum technological
requirements including a double liner, leachate
collection system, and ground-water monitoring system, or
The surface impoundment must meet other alternative
operating practices, design features, or siting
characteristics determined by the EPA Administrator to
be equally protective of human health and the
environment.
A surface impoundment may receive a waiver from the double
liner and leachate collection system requirements if EPA
determines that it meets certain other conditions, including:
It has at least one liner that is not leaking; it is
located more than one-quarter mile from an underground
drinking water source; and it is in compliance with the
applicable ground-water monitoring requirements of RCRA
Section 3005.
or
It is located, designed, and operated so as to ensure
that no hazardous constituents will migrate to ground
water or surface water in the future.
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Owners or operators seeking an exemption for treatment in
surface impoundments must certify to the EPA Regional
Administrator that the impoundment meets the minimum
technological requirements (or is exempt as discussed above),
and must submit a copy of the facility's waste analysis plan.
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5. PROHIBITION ON DILUTION (SECTION 258.3)
The land disposal restrictions rule prohibits the dilution
of restricted wastes as a substitute for adequate treatment to
meet the treatment standards. This provision"ensures that no
individual circumvents the intent of EPA's concentration-based
regulations by simply adding material to wastes that do not
meet the treatment standards, rather than treating the wastes.
Dilution as a necessary part of the waste treatment process
is allowed under the final rule. For example, the addition of
an acidic or basic reagent to a waste in a neutralization pond
does not merely dilute the waste into a larger volume of waste;
rather, the addition of the reagent is a necessary part of the
process of chemically altering the waste so as to render it
less hazardous.
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6. STORAGE PROHIBITION (SECTION 268.50)
Under the land disposal restrictions rule, storage of
restricted wastes is prohibited except where storage is solely
for the purpose of accumulating sufficient quantities of wastes
to facilitate proper treatment, recovery, or disposal.
Treatment, storage, and disposal facilities may store
restricted wastes for as long as needed, provided that such
storage is solely for this purpose. However, if the facility
stores a restricted waste for more than one year, it bears the
burden of proof, in the event of an enforcement action, that
the storage was solely for this purpose (there is no
notification requirement for storage of more than one year).
For storage of less than one year, EPA bears the burden of
proof that such storage was not for the sole purpose of
accumulating sufficient quantities of wastes to facilitate
proper treatment, recovery, or disposal. This prohibition on
storage does not apply to wastes which meet the treatment
standard, wastes which have been granted an extension to the
effective date, and wastes which are the subject of a "no
migration" exemption.
For generators without a RCRA permit or interim status, the
rules governing storage (Section 262.34) have not changed under
the land disposal restrictions rule. Large quantity generators
may store restricted hazardous wastes on-site for 90 days or
less without a permit or interim status. Small quantity
generators of 100 to 1,000 kg of hazardous wastes per month may
accumulate wastes for up to 180 days, or 270 days if the waste
must be transported 200 miles or more to a treatment, storage,
or disposal facility. (The EPA Regional Administrator may
grant a 30-day extension to these storage limits on a
case-by-case basis.) The land disposal restrictions now impose
the additional requirement that such storage must be solely for
the purpose of accumulating sufficient quantities of waste to
facilitate proper treatment, recovery, or disposal.
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As prior to the land disposal restrictions, all generator
storage must comply with the applicable standards of RCRA Part
265, including contingency planning, preparedness and
prevention, and personnel training. In addition, generators
must store their wastes in containers or tanks that are clearly
marked with the words "Hazardous Waste" and with the date on
which the tanks or containers enter storage. All container
markings must be clearly visible for inspection.
If compliance with the land disposal restrictions requires
storage beyond 90 days (or 180 days for small quantity
generator waste), generators must obtain RCRA interim status or
a RCRA permit. For a generator to qualify for interim status,
the wastes must have been placed into storage in tanks or
containers before the effective date of the restrictions. A
generator must also demonstrate that the additional storage
time is necessary to comply with the land disposal
restrictions. Generators who need to obtain interim status
must submit a Part A application to EPA by the earlier of two
deadlines:
Six months after publication of regulations which first
require the facility to comply with RCRA Part 265.
Thirty days after the date the facility first becomes
subject to the Part 265 standards. This is the most
likely deadline for most generators since a generator
first becomes subject to the permitting requirements
when the accumulation time limit is exceeded.
Interim status granted under these conditions will apply only
to those restricted wastes identified in the Part A application,
Generators who obtain interim status are subject to the
applicable RCRA Part 265 standards. EPA can take corrective
action against these generators pursuant to Section 3008(h) for
failure to comply with these standards. EPA can also require
the generator to submit a Part B permit application.
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The rules governing storage at transfer facilities (Section
263.12) have not changed under the land disposal restrictions.
Transporters may store restricted wastes at a transfer facility
for up to 10 days without a permit or interim status.
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7. PERMIT PROGRAM
Interim Status Facilities
Under RCRA, treatment facilities operating under interim
status may make certain changes to their operations which
enable them to handle new wastes. These changes include:
Accepting new wastes.
Increasing design capacity (if the facilities can
demonstate to EPA that there is a lack of available
capacity).
Changing treatment, storage or disposal processes as
necessary to comply with state or local laws.
To accept new wastes, interim status facilities must, revise
their Part A permit applications. To increase the design
capacity or change a treatment, storage, or disposal process,
an interim status facility must obtain prior approval from
EPA. RCRA limits these changes to facility alterations and
expansions that do not exceed 50 percent of the capital cost of
a comparable new facility.
In a notice published in the Federal Register on December
11, 1986, EPA proposed to give interim status treatment and
storage facilities more flexibility in managing wastes
restricted from land disposal. EPA proposed to allow these
interim status facilities to expand their operations by more
than 50 percent in order to treat or store restricted wastes in
tanks or containers.
Permitted FaciXities (Section 270.42)
Prior to the November 7, 1986 land disposal restrictions
rule, permitted treatment facilities did not have the same
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flexibility to make waste management changes as interim status
facilities. In the November 7th rulemaking, EPA made some
changes (Section 270.42) which will allow permitted facilities
to treat restricted wastes more promptly and to increase the
availability of treatment capacity. A permitted facility may
now treat restricted wastes not identified in the permit if the
treatment is such that the treatment residual meets the
applicable treatment standards. In addition, permitted
facilities may treat new wastes as long as such treatment does
not pose substantially different risks from the risks
associated with wastes included in the permit. These changes
require an EPA-approved minor permit modification.
EPA proposed in the December 11, 1986 notice to give
permitted treatment and storage facilities more flexibility in
managing wastes restricted from land disposal. EPA proposed to
allow these permitted facilities, through the minor permit
modification process, to change their operations so as to treat
or store restricted wastes in tanks or containers. The
proposed rule would allow only those changes needed to comply
with the land disposal restrictions rule. These permitted
facilities would be required to submit a major modification
request, which EPA would process at a later date, and to comply
with all applicable requirements of the RCRA Part 264 standards.
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8. TESTING AND RECORDKEEPING (SECTION 268.7)
The testing and recordkeeping requirements of the land
disposal restrictions rule reflect EPA's philosophy of tracking
wastes from generation to ultimate disposal. All restricted
wastes, whether treated and disposed on-site, or sent off-site
to a RCRA treatment or disposal facility or to a non-RCRA
recycling facility (although recycling facilities may be exempt
from RCRA regulation, the wastes they receive and the resulting
residues are regulated by RCRA and subject to the land disposal
restrictions), are subject to some testing and recordkeeping
requirements. Generators, treatment facilities, and land
disposal facilities each have specific responsibilities under
the land disposal restrictions rule; however, the land disposal
facility bears the ultimate responsibility for ensuring that
only wastes meeting the treatment standards (or wastes that are
subject to an exemption or variance) are land disposed.
Generator Responsibilities
The generator is responsible for testing his waste or an
extract of his waste (developed by using the TCLP), or using
knowledge of his waste, to determine if his waste is restricted
from land disposal. If the generator determines that he is
managing a restricted waste, he is responsible for determining
whether his waste meets the applicable treatment standard. The
generator can also make this determination based either on
knowledge of the waste, or by testing the waste or waste
extract (developed by using the TCLP). If the generator has
used knowledge of his waste (whether it is sent to a treatment
facility or a disposal facility) to determine the applicable
treatment standard, or to determine if the applicable standard
has been met without treatment, he must maintain records (at
the location where the waste is generated) of all supporting
data used to make the determination. As prior to the land
disposal restrictions, the generator must also conduct a waste
-------
analysis if there is any reason to believe that the waste
composition or the generating process has changed; he cannot
rely on his knowledge of the waste in such cases.
If the waste meets the treatment standard, the generator
may transport the waste directly to the disposal facility,
providing a notice with the following information:
The EPA Hazardous Waste Number(s).
The applicable treatment standard(s).
The manifest number associated with the waste shipment.
The waste analysis data (if available).
The generator must also provide a certification which states
that the waste delivered to the disposal facility meets the
treatment standard, and that the information included in the
notice is true, accurate, and complete. If EPA has granted an
extension to the effective date for a particular waste, it is
the generator's responsibility to notify the land disposal
facility.
For restricted wastes that do not meet the treatment
standard, the generator must send a notice with each shipment
to the treatment facility. The generator must determine the
appropriate treatment standard based -on waste analysis data,
knowledge of the waste, or both.
Generators who treat and/or dispose of restricted waste
on-site must also comply with the recordkeeping requirements of
treatment and/or disposal facilities (except for the manifest
number).
Treatment Facility Responsibilities
Treatment facilities are responsible for treating
restricted wastes to the levels specified by the applicable
-------
treatment standards, or by the specified technology(ies). A
treatment facility also is responsible for:
Keeping a copy of the notice and any available waste
analysis data provided by the generator in the treatment
facility's operating record.
Testing the treatment residual using the TCLP (according
to the frequency established in the facility's waste
analysis plan) to determine whether it meets the waste
extract concentration level.
Conducting a waste analysis if there is any reason to
believe that the waste composition or the treatment
process has changed.
Where treatment residuals meet the treatment standards, the
treatment facility, like the generator who ships waste directly
to a disposal facility, must submit a notice and certification
to the disposal facility. The certification must state that
the treatment standards have been met in accordance with the
prohibition on dilution, and that the information is true,
accurate, and complete.
Where treatment residuals do not meet the treatment
standards and the facility ships the residuals off-site to
another treatment facility for further treatment, the notice
requirements are the same as for the original generator sending
the wastes to the treatment facility.
Land Disposal Facility Responsibilities
Land disposal facilities are responsible for ensuring that
only wastes meeting the treatment standards (or wastes that are
subject to an exemption or variance) are land disposed. In
addition, land disposal facilities must document that the waste
has been treated in accordance with the applicable EPA
treatment standards. The results of any waste analyses must be
placed in the land disposal facility's operating record, along
with a copy of all certifications and notices.
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9. TREATMENT STANDARDS FOR SOLVENTS (SECTION 268.41)
What Solvent Wastes Are Covered Under the F001-F005 Listing?
(Section 268.31)
Only solvent constituents listed in Table CCWE (Table 2 in
this booklet), when used to solubilize (dissolve) or mobilize
other constituents, are considered spent solvents under the
land disposal restrictions rule. A solvent is considered
"spent" when it has been used and is no longer fit for use
without being regenerated, reclaimed, or otherwise
reprocessed. Examples of spent solvents include solvents that
are used as degreasers, cleaners, fabric scourers, diluents,
extractants, and reaction and synthesis media. Manufacturing
process wastes containing F001-F005 solvent constituents are
not spent solvents where the solvent constituents are reactants
and not carriers (solvents) in the process.
Basis for the Solvent Treatment Standards
EPA identified nine treatment technologies that are
demonstrated and commercially available for F001-F005 spent
solvents. Using data that represented only well-designed and
well-operated systems, EPA calculated average performance
values for each specific waste treated with a particular
technology. Where one technology performed better than others,
EPA based the treatment standard on the best technology. If
several technologies performed equally well, EPA averaged the
performance values and multiplied the average value by a
variability factor to derive the treatment standard. The
variability factor was calculated in to account for
fluctuations inherent in the normal process of well-designed
and well-operated treatment systems.
EPA established three separate treatability groups for
spent solvent wastes:
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Wastewaters (defined for the purposes of Table CCWE as
solvent-water mixtures containing less than or equal to
1 percent total organic carbon [TOC] by weight).
Methylene chloride-containing wastewaters containing
less than or equal to 1 percent TOC generated from
pharmaceutical plants.
All other spent solvent wastes, including wastewaters
containing greater than 1 percent TOC, solvent-
containing solids, solvent-containing sludges, and
solvent-contaminated soils.
Of the nine demonstrated treatment technologies, the
following four technologies formed the basis for the solvent
treatment standards:
Steam stripping.
Biological treatment.
Activated carbon treatment.
Incineration.
The solvent treatment standards are set as concentration levels
based on the above technologies; EPA is not requiring that
these specific technologies be used to meet the treatment
standards. Table 2 lists the spent solvent treatment standards
expressed as concentrations in the treatment residual extract.
Effective Date of Solvent Land Disposal Restrictions (Section
268.30)
The following spent solvent wastes (F001-F005) have been
granted the maximum two-year national variance. Effective
November 8, 1988, these wastes are prohibited from disposal.
Wastes generated by small quantity generators of 100 to
1,000 kg/month of hazardous wastes.
Wastes resulting from CERCLA response actions and RCRA
corrective actions.
Solvent-water mixtures, solvent-containing sludges or
solids, and solvent-contaminated soil containing less
than one percent total F001-F005 solvent constituents.
-------
TABLE 2
SOLVENT TREATMENT STANDARDS3
TABLE CCWE
CONSTITUENTS OF
F001-F005
SPENT SOLVENT WASTES
Acetone
n-Butyl Alcohol
Carbon disulfide
Carbon tetrachloride
Chlorobenzene
Cresols (cresylic acid)
Cyclohexanone
1 ,2-Di Chlorobenzene
Ethyl acetate
Ethylbenzene
Ethyl ether
Isobutanol
Methanol
Methylene chloride
EXTRACT CONCENTRATIONS
WASTEWATER
0.05
5.00
1.05
0.05
0.15
2.82
0.125
0.65
0.05
0.05
0.05
5,00
0.25
0.20b
(mg/1)
OTHER
0.59
5.00
4.81
0.96
0.05
0.75
0.75
0.125
0.75
0.053
0.75
5.00
0.75
0.96
aFor determining the applicable treatment standard,
wastewaters are defined as solvent-water mixtures containing
less than or equal to 1 percent total organic carbon.
bTreatment standard for wastewaters generated from
pharmaceutical plants is 12.7 mg/1.
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TABLE 2 (CONT.)
CONSTITUENTS OF
F001-F005
SPENT SOLVENT WASTES
Methyl ethyl ketone
Methyl isobutyl ketone
Nitrobenzene
Pyridine
Tetrachloroethylene
Toluene
1, 1,1-Trichloroethane
l,l,2-Trichloro-l,2,2-tr
Trichloroethylene
Trichlorof luorome thane
Xylene
EXTRACT CONCENTRATIONS (mg/1)
WASTEWATER
0.05
0.05
0.66
1.12
0.079
1.12
1.05
if luoroethane 1.05
0.062
0.05
0.05
OTHER
0.75
0.33
0.125
0.33
0.05
0.33
0.41
0.96
0.091
0.96
0.15
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10. TREATMENT STANDARDS FOR DIOXINS (SECTION 268.41)
The treatment standards for dioxin-containing wastes F020,
F021, F022, F023, F026, F027, and F028 are based on
incineration to 99.9999 percent destruction and removal
efficiency. The standards require treatment to a level below
the routinely achievable detection limit of 1 ppb (using Method
8280 in SW-846) in the waste extract for the specific isomers
of tetra-, penta-, and hexachlorodibenzo-p-dioxins and
-dibenzofurans listed in Table CCWE. The treatment standards
for the chlorophenols also require treatment to a level below
the routinely achievable detection limit in the waste extract
as listed in Table CCWE.
Table 3 shows the dioxin-containing waste treatment
standards expressed as concentrations in the treatment residual
extract.
Effective Date of Dioxin Land Disposal Restrictions
(Section 268.31)
EPA has determined that there is a lack of treatment
capacity nationwide to handle dioxin wastes, therefore EPA has
granted the maximum two-year national variance to the effective
date of the dioxin land disposal restrictions to allow time for
the regulated community to develop the necessary capacity.
Effective November 8, 1988, the F020-F023 and F026-F028
dioxin-containing wastes are prohibited from land disposal.
-------
TABLE 3
DIOXIN TREATMENT STANDARDS
TABLE CCWE
F020-F023 AND F026-F028
DIOXIN-CONTAINING WASTES
EXTRACT
CONCENTRATIONS
HxCDD - All Hexachlorodibenzo-p-dioxins
HxCDF - All Hexachlorodibenzofurans
PeCDD - All Pentachlorodibenzo-p-dioxins
PeCDF - All Pentachlorodibenzofurans
TCDD - All Tetrachlorodibenzo-p-dioxins
TCDF - All Tetrachlorodibenzofurans
2,4,5-Tr i chlorophe nol
2,4,6-Trichlorophenol
2,3,4,6-Tetrachlorophenol
Pentachlorophenol
< 1 ppb
< 1 ppb
< 1 ppb
< 1 ppb
< 1 ppb
< 1 ppb
< 0.05 ppm
< 0.05 ppm
< 0.10 ppm
< 0.01 ppm
ppb = ug/1
ppm = mg/1
0503K
-------
Appendix A
Information Requirements for a Petition
for a Variance From the Treatment Standard
-------
Appendix A
Information Requirements for a Petition
for a Variance From the Treatment Standard
A petition from the treatment standard must include the
following information:
The petitioner's name and address.
The name, address, phone number, and EPA identification
number of the generating facility and of the facility
contact person.
A description of the waste generating processes and feed
materials.
A detailed description of the petitioner's waste
(including data and information on the physical and
chemical characteristics of the waste) that EPA can use
to compare the,petitioner ' s waste to the wastes
considered by EPA in developing BDAT.
If the waste has been treated, a description of the
treatment system, including the process design,
operating conditions, and an explanation of why the
treatment standards cannot be achieved using the
treatment system, or an explanation of why the specified
treatment technology is inappropriate for the
petitioner's waste.
If the waste has not been treated, an explanation of why
the petitioner believes the waste will react to
treatment differently from the wastes evaluated by EPA
in developing the treatment standard.
A description of any alternative.treatment systems
examined by the petitioner, and, as appropriate, the
concentrations in the treatment residual (using the
TCLP) that can be achieved by applying such treatment to
the waste.
The dates of the sampling and testing.
A description of the methodologies and equipment used to
obtain representative samples.
A description of the sample handling and preparation
techniques.
A description of the tests performed (including results)
-------
Appendix B
Information Requirements for a Petition for a
Case-by-Case Extension to the Effective Date
-------
Appendix B
Information Requirements for a Petition for a
Case-by-Case Extension to the Effective Date
A case-by-case petition must include the following information:
A demonstration that a good faith effort has been made
to locate and contract with hazardous waste treatment,
recovery, or disposal facilities nationwide to handle
the waste.
A demonstration that the petitioner has entered into a
binding contract to construct or otherwise provide
adequate treatment, recovery, or disposal capacity for
the waste.
A demonstration that, due to circumstances beyond the
petitioner's control, alternative treatment, recovery,
or disposal capacity cannot reasonably be made available
by the effective date of the land disposal restriction.
A demonstration that the capacity being constructed or
otherwise provided will be sufficient to manage the
waste.
« A detailed schedule for obtaining all necessary
operating and construction permits and an outline of how
and when alternative capacity will be available.
A demonstration that arrangements have been made for
adequate capacity to manage the waste during the
extension. This demonstration must include an
identification and description of all waste management
sites.
-------
Appendix C
Information Requirements for a Petition for a
"No Migration" Exemption
-------
Appendix C
Information Requirements for a Petition for a
"No Migration" Exemption
A "no migration" petition must include the following
information:
The identification and a full characterization of the
specific waste, including a comprehensive chemical and
physical characterization.
The identification and a comprehensive characterization
of the disposal unit, including background air, soil,
and water quality.
A demonstration that all waste and environmental
sampling, test, and analysis data are accurate and
reproducible.
A demonstration that EPA-approved sampling, testing, and
estimation techniques were used.
A demonstration that all simulation models for the
specific waste and disposal site conditions were
calibrated, and that the models were verified by actual
measurements.
Analyses performed to identify and quantify any aspects
that could contribute significantly to uncertainty
regarding the suitability of the site, including the
potential for damage from earthquakes, floods, severe
storms, droughts, or other natural phenomena.
A quality assurance and quality control plan that
addresses all aspects of the "no migration"
demonstration.
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Title III of SARA
Community Right-to-Know
-------
TITLE III FACT SHEET
EMERGENCY PLANNING AND
COMMUNITY RIGHT-TO-KNOW
EPA
U.S. Environmental Protection Agency
INTRODUCTION
On October 17,1986, the
"Superfund Amendments and
Reauthorization Act of 1986"
(SARA) was enacted into law. One
part of the new SARA provisions is
Title HI: the Emergency Planning
and Community Right-to-Know
Act of 1986. Title HI establishes
requirements for Federal, State, and
local governments and industry
regarding emergency planning and
'community right-to-know'
reporting on hazardous and toxic
chemicals. This legislation builds
upon EPA's Chemical Emergency
Preparedness Program (CEPP) and
numerous State and local programs
aimed at helping communities to bet-
ter meet their responsibilities in
regard to potential chemical emer-
gencies. The community right-to-
know provisions of Title HI will
help to increase the public's knowl-
edge and access to information on
the presence of hazardous chemi-
cals in their communities and
releases of these chemicals into the
environment.
Title III has four major sections:
emergency planning (§301 -
§303), emergency notification
(§304), community right-to-know
reporting requirements (§311,
312), and toxic chemical release
reporting - emissions inventory
(§313).
§301-303: Emergency
Planning:
The emergency planning sections
are designed to develop State and
local governments' emergency
response and preparedness capa-
bilities through better coordination
and planning, especially within the
local community.
Title III requires that the Governor
of each State designate a State emer-
gency response commission by
April 17,1987. If a State commis-
sion is not designated, the Gover-
nor will operate as the commission
until the Governor makes such des-
ignation. While existing State
organizations can be designated as
the State emergency response com-
mission, the commission can have
broad-based representation. Public
agencies and departments con-
cerned with issues relating to the
environment, natural resources,
emergency services, public health,
occupational safety, and transporta-
tion all have important roles in Title
III activities. Various public and
private sector groups and associa-
tions with interest and exper-
tise in Tide III issues also can be
included in the State commission.
The State commission must desig-
nate local emergency planning dis-
tricts by July 17,1987, and appoint
local emergency planning commit-
tees within one month after a dis-
trict is designated. The State com-
mission is responsible for supervis-
ing and coordinating the activities
of the local emergency planning
committees, for establishing proce-
dures for receiving and processing
public requests for information col-
lected under other sections of Title
III, and for reviewing local emer-
gency plans.
This local emergency planning com-
mittee must include elected State
1
and local officials, police, fire, civil
defense, public health profes-
sionals, environmental, hospital,
and transportation officials as well
as representatives of facilities sub-
ject to the emergency planning
requirements, community groups,
and the media. No later than Sep-
tember 17,1987, facilities subject
to the emergency planning require-
ments must designate a representa-
tive to participate in the planning
process. The local committee must
establish rules, give public notice of
its activities and establish proce-
dures for handling public requests
for information.
The local committee's primary
responsibility will be to develop an
emergency response plan by Octo-
ber 17,1988. In developing this
plan, the local committee will evalu-
ate available resources for preparing
for and responding to a potential
chemical accident. The plan must
include:
Identification of facilities and
extremely hazardous substances
transportation routes
Emergency response procedures,
on-site and off-site
Designation of a community coor-
dinator and facility coordinator(s)
to implement the plan
Emergency notification proce-
dures
Methods for determining the
occurrence of a release and the
probable affected area and
population
-------
Key Dates to Remember
November 17,1986
November 17,1986
January 27,1987
March 17.1987
April 17.1987
May 17,1987
June 1.1987
July 17.1987
August 17.1987
(or 30 days after
designation of dis-
tricts, whichever is
sooner)
September 17.1987
(or 30 days after
committee is formed,
whichever is earlier)
October 17,1987
March 1,1988
(and annually there-
after)
April 17.1988
(Continued on page 5)
EPA published List of Extremely Hazardous
Substances and Planning Threshold Quantities
in Federal Register (§302,303,304)
EPA initiates comprehensive review of
emergency systems (§305(b))
Format for Emergency Inventory Forms and
reporting requirements published in Federal
Register (§311,312)
National Response Team publishes guidance for
preparation and implementation of emergency
plans (§303(f))
State governors appoint State emergency
response commissions (§301 (a))
Facilities subject to Section 302 planning
requirements notify State emergency
response commission (§302(c))
Interim report on emergency system review due
to Congress (§305(b))
EPA publishes toxic chemical release
(i.e., emissions inventory) form (§313(g))
State emergency response commission
designates emergency planning districts
(§301 (b))
State emergency response commission appoints
members of local emergency planning
committees (§301 (c))
Facility notifies local planning committee of
selection of a facility representative
(§303(d)(1))
MSDS or list of MSDS chemicals submitted to
State commission, local committee and local
fire department (§311 (d))
Facilities submit their emergency
inventory forms to State commission, local
committee and local fire department (§312(a)(2))
Rnal Report on emergency systems study due
to Congress (§305(b))
Description of community and
industry emergency equipment
and facilities and the identity of
persons responsible for them
Evacuation plans
Description and schedules of a
training program for emergency
response personnel
Methods and schedules for exer-
cising emergency response plans.
In order to assist the local commit-
tees in preparing and reviewing
plans, Congress required the
National Response Team (NRT),
composed of 14 Federal agencies
with emergency response responsi-
bilities, to publish guidance on
emergency response planning.
This guidance, the Hazardous Mate-
rials Emergency Planning Guide,
will be published by the NRT and
incorporates emergency planning
aspects of the CEPP Interim Guid-
ance. It also replaces the Federal
Emergency Management Agency's
Planning Guide and Checklist for
Hazardous Materials Contingency
Plans (popularly know as FEMA-
10). See Federal Register dated
12/2/86.
The emergency response plan must
be reviewed by the State commis-
sion as well as annually by the
local committee. The Regional
Response Teams, composed of the
Federal Regional officials and State
representatives, may review the
plans and provide assistance to the
local committees upon request.
Those planning activities of the
local committees and facilities
should be focused on, but not lim-
ited to, the 402 extremely hazard-
ous substances published in the
November 17,1986, Federal Regis-
ter. The list included the threshold
planning quantities for each sub-
stance. EPA can revise the list and
threshold planning quantities based
on the toxicity, reactivity, volatil-
ity, dispersability, combustability,
or flammability of a substance. I
Any facility that produces, uses, or
stores any of the listed chemicals in
-------
a quantity greater than its threshold
planning quantity is subject to the
emergency planning requirements.
In addition, the State commission
or the Governor can designate
>ditional facilities, after public
mment, to be subject to these
requirements. By May 17,1987,
covered facilities must notify the
State commission that they are sub-
ject to these requirements. If a facil-
ity begins to produce, use, or store
any of the extremely hazardous sub-
stances in threshold quantity
amounts, it must notify the State
commission within 60 days.
Each State commission must notify
EPA of all facilities subject to the
emergency planning requirements,
including facilities designated by
the State commission or the
Governor.
§304: Emergency
Notification
Facilities must immediately notify
the local emergency planning com-
mittee and the State emergency
response commission if there is a
Ease of a listed hazardous sub-
ce that exceeds the reportable
ntity for that substance. Sub-
stances subject to this requirement
are substances on the list of 402
extremely hazardous substances as
published in Federal Register on
11/17/86 and substances subject to
the emergency notification require-
ments under CERCLA Section
103(a).
The initial notification can be by tele-
phone, radio, or in person. Emer-
gency notification requirements
involving transportation incidents
can be satisfied by dialing 911, or
in the absence of a 911 emergency
number, calling the operator.
This emergency notification needs
to include:
The chemical name
n indication of whether the sub-
ance is extremely hazardous
An estimate of the quantity
released into the environment
The time and duration of the
release
The medium into which the
release occurred
Any known or anticipated acute
or chronic health risks associated
with the emergency, and where
appropriate, advice regarding med-
ical attention necessary for
exposed individuals
Proper precautions, such as evacu-
ation
Name and telephone number of
contact person.
Section 304 also requires the fol-
low-up written emergency notice
after the release. The follow-up
notice or notices shall:
Update information included in
the initial notice, and
Provide information on:
- Actual response actions
taken
- Any known or anticipated data
or chronic health risks associ-
ated with the release
- Advice regarding medical atten-
tion necessary for exposed indi-
viduals.
Until State commissions and local
committees are formed, releases
should be reported to appropriate
State and local officials.
§311-312: Community Right-
to-Know Reporting
Requirements
There are two "community right-to-
know" reporting requirements
which apply primarily to manufac-
turers and importers. Section
311 requires that facilities which
must prepare or have available mate-
rial safety data sheets (MSDS)
under the Occupational Safety and
Health Administration (OSHA) reg-
ulations to submit either copies of
its MSDS or a list of MSDS chemi-
cals to:
The local emergency planning
committee
The State emergency response
commission
The local fire department.
If the facility owner or operator
chooses to submit a list of MSDS
chemicals, the list must include the
chemical name or common name of
each substance and any hazardous
component as provided on the
MSDS. This list must be organized
in categories of health and physical
hazards as set forth in OSHA regu-
lations unless modified by EPA.
If a list is submitted, the facility
must submit the MSDS for any
chemical on the list upon the
request of the local planning com-
mittee. Under Section 311, EPA
may establish threshold quantities
for hazardous chemicals below
which no facility must report.
The initial submission of the
MSDSs or list is required no later
than October 17,1987, or 3 months
after the facility is required to pre-
pare or have available an MSDS
under OSHA regulations. A
revised MSDS must be provided to
update MSDS which were
originally submitted if significant
new information regarding a chemi-
cal is discovered.
The reporting requirement of Sec-
tion 312 involves submission of
an emergency and hazardous chemi-
cal inventor}' form to the local emer-
gency planning committee, the State
emergency response commission
and the local fire department. The
hazardous chemicals covered by
Section 312 are the same for
which facilities are required to sub-
mit MSDS or the list for Section
311.
Under Section 312, EPA may
also establish threshold quantities
for hazardous chemicals below
which no facility must be subject to
this requirement.
The inventory form incorporates a
two-tier approach. Under Tier I,
-------
facilities must submit the following
aggregate information for each appli-
cable OSHA category of health and
physical hazard:
An estimate (in ranges) of the
maximum amount of chemicals
for each category present at the
facility at any time during the pre-
ceding calendar year
An estimate (in ranges) of the
average daily amount of chemi-
cals in each category
The general location of hazardous
chemicals in each category.
Upon request of a local committee,
State commission or local fire
department, the facility must pro-
vide the following Tier II informa-
tion for each substance subject to
the request:
The chemical name or the com-
mon name as indicated on the
MSDS
An estimate (in ranges) of the
maximum amount of the chemical
present at any time during the pre-
ceding calendar year
A brief description of the manner
of storage of the chemical
The location of the chemical at the
facility
An indication of whether the
owner elects to withold location
information from disclosure to
the public.
The public may also request Tier II
information from the State commis-
sion and the local committee. The
information submitted by facilities
under Sections 311 and 312
must generally be made available to
the public by local and State govern-
ments during normal working
hours.
EPA published a uniform format
for the inventory forms on January
27,1987. Tier I information shall
be submitted on or before March 1,
1988, and annually thereafter on
March 1.
§313: Toxic Chemical
Release Reporting
Section 313 of Title III requires
EPA to establish an inventory of
toxic chemical emissions from cer-
tain facilities. Facilities subject to
this reporting requirement are
required to complete a toxic chemi-
cal release form for specified chemi-
cals. The form must be submitted
to EPA and those State officials des-
ignated by the Governor, on or
before July 1,1988, and annually
thereafter on July 1, reflecting
releases during each preceding cal-
endar year.
The purpose of this reporting
requirement is to inform govern-
ment officials and the public about
releases of toxic chemicals in the
environment. It will also assist in
research and the development of reg-
ulations, guidelines, and standards.
The reporting requirement applies
to owners and operators of facilities
that have 10 or more full-time
employees, that are in Standard
Industries Classification Codes 20
through 39 (i.e., manufacturing
facilities) and that manufactured,
processed or otherwise used a listed
toxic chemical in excess of speci-
fied threshold quantities.
Facilities using listed toxic chemi-
cals in quantities over 10,000
pounds in a calendar year are
required to submit toxic chemical
release forms by July 1 of the
following year. Facilities manufac- /
turing or processing any of these
chemicals in excess of 75,000
pounds in 1987 must report by July
1,1988. Facilities manufacruring
or processing in excess of 50,000
pounds in 1988 must report by July
1,1989; thereafter, facilities manu-
facturing or processing more than
25,000 pounds in a year are
required to submit the form. EPA
can revise these threshold quantities
and covered SIC categories.
The list of toxic chemicals subject
to reporting consists initially of
chemicals listed for similar
reporting purposes by the States of
New Jersey and Maryland. There
are over 300 chemicals and
categories on these lists. EPA can
modify this combined list. In add-
ing a chemical to the combined
Maryland and New Jersey lists,
EPA must consider the following
factors:
Is the substance known to cause
cancer or serious reproductive or
neurological disorders, genetic
mutations, or other chronic health
effects?
Can the substance cause signifi-
cant adverse acute health effects
outside the facility as a result of
continuous or frequently recur-
ring releases?
Can the substance cause an
adverse effect on the environment
because of its toxicity, persist-
ence, or tendency to
bioaccumulate?
Chemicals can be deleted if there
insufficient evidence to establish
any of these factors. State gove-
nors may petition the Administ-
to add or delete a chemical fror
list for any of the above reason
Any person may petition for tv
first two reasons.
Through early consultation with
States or EPA Regions, petitioners
can avoid duplicating previous peti-
tions and be assisted in locating
sources of data already collected or
the problem of concern to support
their petitions. EPA will conduct
information searches on chemicals
contained in a petition, focusing on
the effects the petitioners believes
warrant addition or deletion.
EPA is required to publi '. a format
for the Toxic Chemical ^ase
form by June 1,1987. 1
following information ir . t be
included:
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The name, location and type of
business
Whether the chemical is manufac-
tured, processed, or otherwise
used and the general categories of
use of the chemical
An estimate (in ranges) of the
maximum amounts of the toxic
chemical present at the facility at
any time during the preceding
year
Waste treatment/disposal methods
and efficiency of methods for
each wastestream
Quantity of the chemical entering
each environmental medium
annually
A certification by a senior official
that the report is complete and
accurate.
EPA must establish and maintain a
national toxic chemical inventory
based on the data submitted. This
information must be computer acces-
sible on a national database.
In addition to the requirements for
the emissions inventory in Section
313, EPA will arrange for a mass
balance study to be carried out by
the National Academy of Sciences
using information collected from
States that conduct a mass balance-
oriented annual quantity toxic chemi-
cal release program. Mass balance
is the accounting of the total quan-
tity of substances brought into a
facility versus the amount that is
shipped out. The difference is an
indication of the amount released
into the environment. A report of
this study must be submitted by
EPA to Congress no later than Octo-
ber 17,1991.
The purpose of this study is to
assess the value of obtaining mass
balance information to determine
the accuracy of information on toxic
chemical releases. Also, the study
will assess the value of using the
information for determining the
waste reduction efficiency and for
evaluating toxic chemical manage-
ment practices at categories of
facilities. In addition, the study
must determine the implications of
mass balance information collected
on a national scale including for use
as part of a national annual quantity
toxic chemical release program.
Other Title III Provisions
Section 322 of Title III addresses
trade secrets and applies to emer-
gency planning, community right-to-
know, and toxic chemical release
reporting. Any person may withold
the specific chemical identify of a
hazardous chemical for specific rea-
sons. Even if the chemical identity
is withheld, the generic class or cate-
gory of the chemical must be pro-
vided. The withholder must show
each of the following:
Key Dates to Remember
(Continued from page 2)
July 1.1988
(and annually there-
after)
October 17,1988
June 30,1991
October 17,1991
Covered facilities submit initial toxic
chemical forms to EPA and designated State
officials (§313(a))
Local emergency planning committees
complete preparation of an emergency plan
(§303(a))
Comptroller general report to Congress on
toxic chemical release information collection,
use and availability (§313(k))
EPA report to Congress on Mass Balance Study
(§313(1))
The information has not been dis-
closed to any other person other
than a member of the local plan-
ning committee, a government
official, an employee of such per-
son or someone bound by a confi-
dentiality agreement, that meas-
ures have been taken to protect
the confidentiality, and that the
withholder intends to continue to
take such measures
The information is not required to
be disclosed to the public under
any other Federal or State law
The information is likely to cause
substantial harm to the competi-
tive position of the person
The chemical identity is not read-
ily discoverable through reverse
engineering.
However, even if chemical identity
information can be legally withheld
from the public, Section 323 pro-
vides for disclosure under certain
circumstances to health profes-
sionals who need the information
for diagnostic purposes or from
local health officials who need the
information for assessment
activities. In these cases, the per-
son receiving the information must
be willing to sign a confidentiality
agreement with the facility.
Information claimed as trade secret
and substantiation for that claim
must be submitted to EPA. This
includes information that otherwise
would be submitted only to State or
local officials, such as the emer-
gency and hazardous material inven-
tory (§312). People may chal-
lenge trade secret claims by
petitioning EPA, which must then
review the claim and rule on its
validity.
EPA must publish regulations
governing trade secret claims. The
regulations will cover the process
for submission of claims, petitions
for disclosure and a review process
for these petitions.
Secton 305 of Title III authorizes
the Federal Emergency Manage-
ment Agency to provide $5 million
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Summary for Chemical Lists for Title III
LIST
Section
Purpose
List of Extremely
Hazardous Substances
(FR 11/17/86)
[402 substances]
§302: Emergency
Planning
§304: Emergency
Notification
Substances requiring §304:
notification under Section
103(a)ofCERCLA
[717 substances]
Hazardous Chemicals §304:
considered physical or
health hazards §311:
under OSHA's
Hazard Communication §312:
Standard
[This is a performance
standard, mere is no
specific list of chemicals]
Toxic Chemicals §313:
identified as of concern by
States of New Jersey and
Maryland
[329 chemicals/chemical
categories]
Emergency
Notification
Emergency
Notification
Material Safety
Data Sheets
Emergency
Inventory
Toxic Chemical
Release Reporting
Facilities with more than established planning
quantities of these substances must notify the State
commission
Initial Focus for preparation of emergency plans by
local emergency planning committees
Certain releases of these substances trigger Section
304 notification to State commission and local
committees
Certain releases of these substances trigger Section
notification to State commission and local
committees as well as Section 103(a) requirement
for National Response Center notification
Identifies facilities subject to emergency
notification requirements
MSDS or list of MSDS chemicals
provided by covered facilities to State
commission, local committee,
and local fire department
Covered facilities provide site-specific
information on chemicals to State
commission, local committees and
local fire departments
These chemicals are reported on an
emissions inventory to inform government
officials and the public about releases of
toxic chemicals in the environment.
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for each of fiscal years 1987,1988,
1989, and 1990 for training grants
to support State and local govern-
ments. These training grants are
designed to improve emergency
planning, preparedness, mitigation,
response, and recovery capabilities.
Such programs must provide spe-
cial emphasis to hazardous chemical
emergencies. The training grants
may not exceed 80 percent of the
cost of any such programs. The
remaining 20 percent must come
from non-Federal sources.
Under Section 305, EPA is
required to review emergency sys-
tems for monitoring, detecting, and
preventing releases of extremely
hazardous substances at representa-
tive facilities that produce, use, or
store these substances. EPA will
report interim findings to Congress
no later than May 17,1987 and
issue a final report of findings and
recommendations to Congress by
April 17,1988.
The report must include EPA's find-
ings regarding each of the
following:
Status of current technological
capabilities to (1) monitor, detect,
and prevent significant releases of
extremely hazardous substances;
(2) determine the magnitude and
direction of the hazard posed by
each release; (3) identify specific
substances; (4) provide data on
specific chemical composition of
such releases; and (5) determine
relative concentration of the con-
stituent substances.
Status of public emergency alert
devices or systems for effective
public warning of accidental
releases of extremely hazardous
substances into any media.
The technical and economic feasi-
bility of establishing,
maintaining, and operating alert
systems for detecting releases.
The report must also include EPA's
recommendations for:
Initiatives to support development
of new or improved technologies
or systems that would assist the
timely monitoring, detection, and
prevention of releases of
extremely hazardous substances.
Improving devices or systems for
effectively alerting the public in
the event of an accidental release.
For more information on Title III and
EPA's Chemical Emergency Prepared-
ness Program, contact the CEPP
Hotline:
1-800-535-0202
(in Washington. D.C. (202) 479-2449)
Hours: 8:30 am - 4:30 pm (EST),
Monday-Friday
This Is NOT an emergency
number
Title III - Major Information Flow Requirements
Guidance/
Assistance
(§303 & §305)
Emergency
Response Plan
Designated
State Official
Emergency
Notification
(§304)
Toxic Chemical
Release Form
(§313)
Emergency
Planning
(§301 -6303)
MSDS or
LIST
(§311)
Emergency
Inventory
!§312)
FACILITIES
BUB oovziunuitT nurnio ornci 1W7 - 713-872 - U02/UIO
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Liability Issues for Source Reduction,
Recycle, and Treatment
Robert A. Wyman
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TABLE OF CONTENTS
I. INTRODUCTION 1
II. HSWA: WASTE TREATMENT AND MINIMIZATION REQUIRE-
MENTS 2
A. LAND DISPOSAL BAN 2
1. Disposal prohibitions 2
2. Timetable for compliance 2
3. Exemptions and variances 3
4. Storage prohibitions 4
5. Treatment standards 5
6. Testing and recordkeeping requirements . . 5
a. Generator requirements 6
b. Treatment facility requirements ... 7
c. Land disposal facility requirements . 7
7. Generator liability for non-compliance
with land disposal restrictions 7
B. WASTE MINIMIZATION 8
1. Statutory requirements 8
2. Description of waste minimization
activities 9
3. Generator liability for non-compliance
with waste minimization requirements . . 10
III. COMPLYING WITH WASTE TREATMENT AND MINIMIZATION
REQUIREMENTS: GENERATOR OPTIONS AND THE "LIABILITY
HIER-ARCHY" 11
A. OPTION ONE: SOURCE REDUCTION 12
1. Liability considerations 12
2. Other considerations 12
B. OPTION TWO: RECYCLING AND RESOURCE RECOVERY . 13
1. Liability considerations 14
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2. Other considerations 15
C. OPTION THREE: TREATMENT AND LAND DISPOSAL . . 15
1. Liability considerations 16
a. Statutory liability 16
(1) RCRA 16
(2) CERCLA 17
b. Common law liability 18
c. Recommendations 19
2. Other considerations 20
a. Obtaining an exemption or variance
from the land disposal restrictions 20
b. Off-site treatment and disposal:
capacity limitations 21
c. On-site treatment and disposal:
permitting difficulties 23
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I. INTRODUCTION
This country spends more than 70 billion dollars
each year on environmental protection and compliance. A
large part of this expenditure has been directed towards the
proper management and disposal of hazardous wastes as
specified in the Resource Conservation and Recovery Act of
1976 (RCRA) (42 U.S.C. § 6901 et sea.). and the Comprehensive
Environmental Response, Compensation and Liability Act of
1980 (CERCLA) (42 U.S.C. § 9601 e± seq.).
The Office of Technology Assessment (O.T.A.)
estimates that industry today produces at least 575 million
tons of hazardous wastes per year. Furthermore, EPA has
concluded that many parts of the country lack or will soon
lack adequate treatment and disposal capacity to deal with
the volume of hazardous waste generated. Even where there is
sufficient treatment and disposal capacity, the treatment or
disposal methods have failed to eliminate, or even reduce to
acceptable levels, the risk of an unintentional release. At
the same time, industry has sought ways to reduce
liabilities associated with hazardous substance handling and
disposal. These trends have motivated federal and state
legislatures to focus attention towards waste reduction
strategies such as recycling and source reduction and away
from "end-of-the-pipe" solutions such as the permitting of
new landfills and waste treatment, storage and disposal (TSD)
facilities.
By amending RCRA in 1984, Congress established
hazardous waste reduction as a national priority. See 42
U.S.C. §6902(b). These amendments, known as The Hazardous
and Solid Waste Amendments of 1984 (HSWA), impose substantial
new legal responsibilities on hazardous waste generators,
treaters, and disposers. HSWA creates a presumption against
land-based disposal by requiring that hazardous waste
generators voluntarily institute in-house waste minimization
programs, meet pre-disposal treatment standards for certain
hazardous wastes, and equip new landfills and other waste
disposal facilities with additional technological controls
prior to receiving wastes.
This paper addresses the legal incentives that
HSWA and related EPA regulations create to reduce hazardous
waste production. Specific land disposal and waste minimiza-
tion requirements of HSWA are described, followed by a
discussion of three compliance options currently available to
hazardous waste generators: source reduction, recycling and
resource recovery, and treatment and land disposal. Each
option is analyzed in terms of the liability risks and/or
protections it provides, as well as other general short and
long-term considerations that a generator should take into
account before selecting a particular option.
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II. HSWA; WASTE TREATMENT AND MINIMIZATION REQUIREMEHTS
A. LAND DISPOSAL BAN
1. Disposal prohibitions
HSWA mandates that the continued land disposal
of untreated hazardous wastes beyond specified dates is
prohibited1 unless EPA determines that the prohibition is
not necessary in order to protect human health and the
environment for as long as the waste remains hazardous. RCRA
§§ 3004 (d),(e),(g); 42 U.S.C. §6924(d),(e),(g) . In
addition, HSWA requires EPA to identify levels or methods of
treatment, if any, that substantially diminish the toxicity
or migration potential of a waste and minimize threats to
human health and the environment. Wastes treated in
accordance with standards set under this section are not
subject to the prohibition and may be land disposed. RCRA
§3004(m).2
The disposal restrictions apply prospectively to persons
who generate or transport hazardous waste and to owners
and operators of hazardous waste treatment, storage, and
facilities, including both interim status and
permitted facilities. 51 Fed. Reg. 40638 (Nov. 7,
1986), to be codified at 40 C.F.R. §268.1. "Land
disposal" is defined to include placement in a landfill,
surface impcundment, waste pile, injection well, land
treatment facility, salt dome formation, salt bed
formation, underground mine or cave, concrete vault or
bunker intended for disposal purposes, or placement in
or on land by means of open detonation and open burning
where the residues continue to exhibit one or more
characteristics of hazardous waste. 51 Fed. Reg. 40638
(Nov. 7, 1986), to be codified at 40 C.F.R. § 268. 2(a).
Determinations regarding injection well and surface
iiqpoundment disposal are treated differently. Under
RCRA §3004(f), EPA is to review deep well injection
methods for liquid hazardous wastes, solvents, and
dioxins by August 1988. Under RCRA §3005(j), wastes
treated in surface inpcundments are exempted from the
land disposal restrictions if the impoundments meet the
minimum technological requirements of RCRA §3004(0)
(with limited exceptions) and the treatment residues
which are hazardous are removed for subsequent manage-
ment within one year of the entry of the waste into the
surface impoundment..
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HSWA sets forth a detailed timeline for EPA
determination of treatment standards. If the Agency fails to
meet a statutory deadline, further land disposal of the
affected group of wastes is automatically prohibited or
conditionally prohibited under a hammer provision. EPA was
required to set treatment standards for F001-F005 solvents
and dioxin wastes by November 8, 1986, and for "California
List" wastes by July 8, 1987. The Agency has completed both
sets of standards. 51 Fed. Reg. 40642 (Nov. 7, 1986), to be
codified at 40 C.F.R. §268 Subpart D; 52 Fed. Reg. 25760
(July 8, 1987), to be codified at 40 C.F.R. §268.4. Further-
more, the Agency must review and set standards for the first
one-third of its remaining listed wastes by August 8, 1988;
the second one-third by June 8, 1989; and the last one-third
by May 8, 1990. (For a schedule of specific listed wastes to
be evaluated, see 40 CFR Subpart B, §268.10-.13).
3. Exemptions and variances
A generator (or any interested person) may
petition that a certain waste be exempted from the land
disposal restrictions. The petitioner must demonstrate, to a
reasonable degree of certainty, that there will be no
migration of hazardous constituents from the land disposal
unit or injection zone (including air emissions) for as long
as the waste remains hazardous. RCRA §§3004(d)(1), (e)(1),
and (g)(5).
In addition to an exemption, three types of
variances are available under the statute: (1) variance based
on lack of national capacity; (2) variance from the treatment
standard; and (3) case-by-case extensions.
First, EPA can grant a national variance of up
to two years if the Agency determines there is a nationwide
lack of capacity to treat specific wastes. Because EPA has
determined that the land disposal restrictions will create a
national shortage of wastewater treatment and incineration
capacity, the Agency has granted such a variance for (1)
small quantity generators of 100-1000 kilograms of non-acute
hazardous waste per month or less than one kilogram of acute
hazardous waste per month, (2) solvent wastes generated by
response or corrective actions taken under CERCLA or RCRA,
and (3) dilute F001-F005 solvent wastes containing less than
1% total organic constituents.3 As a result, these
The variance granted by EPA for dilute solvent wastes is
currently being challenged by the Hazardous Waste Treatment
Council (HWTC) and other groups (HWTC v. EPA. CADC No. 86-
1657). These groups claim that EPA's interpretation of the
variance provisions, which allows exempted wastes to be
disposed of in RCRA - approved facilities, will allow these
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subgroups do not have to comply with treatment standards
until November 8, 1988 provided that their wastes are managed
in facilities that are in compliance with the requirements of
RCRA §3004(o) (Landfills or other hazardous waste facilities
receiving permits after November 8, 1984, must contain double
liner with leachate collection and leak detection systems and
groundwater monitors). 51 Fed. Reg. 40579 (November 7,
1986), to be codified at 40 C.F.R. §268.30.
Second, a generator may request a variance
from the treatment standard if the waste produced is a unique
waste that cannot be treated to the levels specified as the
treatment standard because, for example, the waste does not
fit into one of the Best Demonstrated Available Technology
(BOAT) treatability groups. 51 Fed. Reg. 40605 (November 7,
1986).
Third, the Agency will consider granting indi-
vidual extensions of up to two years if the applicant can
demonstrate: (1) that a good-faith effort has been made to
locate and contract with alternative technologies nationwide;
(2) that a binding contract has been entered into to con-
struct or otherwise provide alternative treatment, recovery,
or disposal capacity that cannot reasonably be made available
by the applicable effective date due to circumstances beyond
the applicant's control. In demonstrating that capacity
cannot reasonably be made available, the applicant may show
that it is not feasible to provide such capacity because of
technical and practical difficulties; and (3) that the
capacity will be sufficient to manage all of the waste
covered by the application. In addition, an applicant must
provide a detailed schedule for providing capacity and
document locations with adequate capacity to manage its
wastes during the extension. Any landfill or surface
impoundment receiving waste during the extension must comply
with the technology requirements of RCRA §3004(o). 51 Fed.
Reg. 40639, (Nov. 7, 1986), to be codified at 40 C.F.R.
§268.5.
In the event that an extension is granted, an
applicant is exempted from the disposal restrictions for the
length of the extension, including the conditional storage
prohibitions discussed below.
4. Storage prohibitions
wastes to be disposed of in old units that do not have to
meet the minimum technological requirements under RCRA
§3004(0) for new facilities. Plaintiffs contend that such an
interpretation will penalize companies that have made big
investments to comply with the minimum technological require-
ments and are currently able to accept the exempted wastes.
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The Agency has set forth three different time
limits for the storage of restricted wastes. First, facility
owners and operators may store restricted wastes as needed to
accumulate sufficient quantities necessary for proper
recovery, treatment, or disposal. If storage exceeds one
year, however, the burden of proof is on the owner/operator
to show that such storage is necessary. Second, transporters
of restricted wastes are subject to a ten-day storage limit.
Third, generators who store restricted wastes in excess of
the accumulation time limits set forth in 40 CFR 262.34 must
obtain interim status and eventually a permit. 51 Fed. Reg.
40642-43 (Nov. 7, 1986), to be codified at 40 C.F.R. §268.50.
For large quantity generators, the applicable time limit is
90 days; small quantity generators can store wastes for 180
or 270 days depending on transportation distances.
5. Treatment standards
Congress has required EPA to use a Best
Demonstrated Available Technology (BDAT) framework to
establish treatment standards for restricted wastes. HSWA
specifies that BDAT may be expressed as either a performance
standard or a method.of treatment. The Agency has expressed
a preference for concentration-based performance standards to
ensure that the technology is properly operated and to allow
those regulated the greatest degree of flexibility possible.
51 Fed. Reg. 40580 (November 7, 1986). In order to determine
whether a waste requires treatment and whether applicable
treatment standards have been met, the Toxicity Characte-
ristic Leaching Procedure (TCLP) must be used.
- Treatment standards for F001-F005 spent
solvents
EPA determined final BDAT treatment standards
for spent solvents on November 7, 1986. 51 Fed. Reg. 40607
(November 7, 1986). The standards are expressed as con-
centrations in the treatment residual extract, and therefore
allow use of any technology that can meet the standard. The
technologies utilized by EPA in setting the standards were
stream stripping, biological treatment, carbon adsorption and
incineration. 51 Fed. Reg. 40610 (November 7, 1986).
Dilution is specifically prohibited as a substitute for
treatment. 51 Fed. Reg. 40639 (Nov. 7, 1986), to be codified
at 40 C.F.R. §268.3.
Industries most affected by the solvent wastes
standards include those where solvents are used as reactant
carriers, for surface preparation, for degreasing, or as a
base for paint and ink.
6. Testing and recordkeepina requirements
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Although the Agency has acknowledged that the
ultimate responsibility for proper disposal of restricted
wastes lies with the land disposal facilities, it has imposed
substantial waste analysis, notice and recordkeeping require-
ments on generators and treatment facilities as well.
a. Generator requirements
The generator must first test its hazardous
wastes either by using the Toxicity Characteristic Leaching
Procedure or by relying on its knowledge of the waste to
determine if the waste is restricted from land disposal. 51
Fed. Reg. 40641 (Nov. 7, 1986), to be codified at 40 C.F.R.
§268.7(a).
If the waste is restricted, the generator must
notify the treatment or recycling facility in writing at the
time of shipment of the appropriate treatment standard for
the waste, the EPA Hazardous Waste Number, the manifest
number associated with the shipment of waste, and any
available waste analysis data. The treatment or recycling
facility (or the generator itself if it is also the TSD
facility) must keep a record of the notice. 51 Fed. Reg.
40641 (Nov. 7, 1986), to be codified at 40 C.F.R.
§268.7(a)(1).
A generator who determines that the waste can
be land disposed without treatment must submit to the
disposal facility a certification statement4 and a notice
which contains the EPA Hazardous Waste Number, the manifest
number, the applicable treatment standard(s), and any
available waste analysis data. Generators disposing on-site
must keep the same information in the operating record. The
above requirements apply to all generators dealing with
restricted wastes, whether they are land disposing the wastes
or merely recycling or reusing them. 51 Fed. Reg. 40641
4 The certification must be signed by an authorized
representative and must state the following:
I certify under penalty of law that I personally have
examined and am familiar with the waste through analysis
and testing or through knowledge of the waste to support
this certification that the waste complies with the
treatment standards specified in 40 CFR Part 268 Subpart
D. I believe that the information I submitted is true,
accurate and complete. I am aware that there are sig-
nificant penalties for submitting a false certification,
including the possibility of a fine and imprisonment.
51 Fed. Reg. 40641 (Nov. 7, 1986), to be codified at 40
C.F.R. §268.7(a)(2)(ii).
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(Nov. 7, 1986), to be codified at 40 C.F.R. §268.7(a)(2) and
(3).
b. Treatment facility requirements
The treatment facility is responsible for
treating the waste in accordance with the applicable treat-
ment standard, and must test waste residues under its waste
analysis plan and certify5 its results to the disposal
facility. The same requirements would apply to a recycling
facility disposing of hazardous waste residues. If further
treatment is required such that the waste must be shipped to
another treatment or recycling facility, the treatment or
recycling facility initiating shipment is subject to the
notice requirements applicable to generators. 51 Fed. Reg.
40641 (Nov. 7, 1986), to be codified at 40 C.F.R. § 268.7(b).
c. Land disposal facility requirements
In addition to maintaining all notices,
certifications and waste data in its operating records, a
land disposal facility must have a testing procedure for
ensuring that the wastes received conform to the certifica-
tions made by generators and treatment facilities and are in
compliance with the applicable treatment standards. 51 Fed.
Reg. 40641 (Nov. 7, 1986), to be codified at 40 C.F.R.
§268.7(c).
7. Generator liability for non-compliance with
land disposal restrictions
A generator could be held liable for non-
compliance with land disposal restrictions in at least two
The certification must be signed by the treater or his
authorized representative and must state the following:
I certify under penalty of law that I have
personally examined and am familiar with the
treatment technology and operation of the treatment
process used to support this certification and
that, based on my inquiry of those individuals
immediately responsible for obtaining this
information, I believe that the treatment process
has been operated and maintained properly so as to
achieve the treatment standards of the specified
technology without dilution of the prohibited
waste. I am aware that there are significant
penalties for submitting a false certification
including the possibility of fine and imprisonment.
51 Fed. Reg. 40641 (Nov. 7, 1986), to be codified
at 40 C.F.R. §268.7(b)(2)(i).
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ways. First, if a -venerator's hazardous wastes were not
being treated propt. ly and therefore exceeding treatment
standard levels at .lie time of disposal, EPA could track the
wastes back to the generator through the manifest system and
impose penalties of up to $25,000 per day for non-compliance
with RCRA requirements. RCRA §3008(a)(3); 42 U.S.C.
§6928(a)(3). Such a result could occur even if the generator
were to send its wastes to a recycler and the recycler failed
to treat the wastes properly prior to disposal. As a
practical matter, however, EPA may choose to institute
enforcement proceedings against the non-complying TSD
facility before trying to locate the responsible generator.
Second, a generator could be held criminally
liable under RCRA §3008(d)(3) if, in sending its wastes
directly to a land disposal facility, the generator fails to
certify or falsely certifies under 40 CFR §268.7 that the
wastes can be land disposed without further treatment.
B. WASTE MINIMIZATION
1. statutory requirements
HSWA mandates that as of September 1, 1985,
generators6 are required to certify on hazardous waste
manifests and on-site treatment, storage, and disposal permit
applications that (1) the generator has a program in place to
reduce the volume or quantity and toxicity of hazardous
wastes to the degree determined by the generator to be
economically practicable; and (2) that the waste management
methods used by the generator minimize present and future
threats to human health and the environment. RCRA §3002; 42
U.S.C. §6922. EPA has revised the Uniform Hazardous Waste
Manifest Form to include a supplemental statement in Item 16
containing the required certification. 50 Fed. Reg. 28733
(July 15, 1985). In addition, generators must report to EPA
at least biannually on the results of efforts undertaken
during the year to minimize wastes. RCRA §3005, 42 U.S.C.
§6925.
EPA is currently drafting waste minimization
reporting forms to be completed by all generators that exceed
small quantity levels (1000 kg or more of hazardous waste per
month or accumulated at any time; more than 1 kg of acute
hazardous waste per month or accumulated at any time; or more
than 100 kg of spill cleanup material contaminated with acute
hazardous waste accumulated at any time). It should be noted
that generators must comply with state in lieu of federal
reporting requir'Tients if the state has been authorized to
EPA has exempted certain small quantity generators from
the certification requirements. 50 Fed. Reg. 28733
(July 15, 1985).
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administer a RCRA program. The reporting forms must be
completed by March 1, 1988, and no information may be
withheld on the basis of confidentiality.
2. Description of waste minimization activities
In its October 1986 Report to Congress, EPA
broadly defines waste minimization as:
"The reduction, to the extent feasible, of
hazardous waste that is generated or subsequently treated,
stored, or disposed of. It includes any source reduction or
recycling activity undertaken by a generator that results in
either (1) the reduction of total volume or quantity of
hazardous waste or (2) the reduction of toxicity of hazardous
waste, or both, so long as such reduction is consistent with
the goal of minimizing present and future threats to human
health and the environment."
See Report to Congress on Minimization of Hazardous Waste.
Office of Solid Waste, October 1986, p. 6. Included in the
definition of waste minimization is the concept of waste
treatment, encompassing technologies such as incineration,
chemical detoxification, and biological treatments. Report
at pp. iii-iv. In addition, EPA has indicated that in
certain circumstances waste concentration and expansion
techniques, or even volume reduction alone, may be beneficial
waste minimization practices if they enhance protection of
the environment. (pp. iv, 13-14).
Although EPA has defined waste minimization
practices broadly to include source reduction, recycling, and
treatment techniques, its preferred waste management hierar-
chy, in descending order, is as follows (pp. 5-6):
(1) Waste reduction: Reducing the amount of
waste at the source through changes in industrial
processes, including some types of treatment
processes, process modifications, feedstock
substitutions or improvements in feedstock purity,
various housekeeping and management practices,
increases in the efficiency of machinery, and
recycling within a process;
(2) Waste separation and concentration:
Isolating wastes from mixtures in which they occur;
(3) Waste exchange: Transferring wastes
through clearinghouses so that they can be recycled
in industrial processes;
(4) Energy/material recovery: Revising and
recycling wastes for the original or some other
-------
purpose, such as for materials recovery or energy
production;
(5) Incineration/treatment: Destroying,
detoxifying and neutralizing wastes into less
harmful substances; and
(6) Secure land disposal: Depositing wastes
on land using volume reduction, encapsulation,
leachate containment, monitoring, and controlled
air and surface/substance water releases.
3. Generator liability for non-compliance vith.
waste minimization requirements
Although the HSWA waste minimization provi-
sions require several certifications from the generator,
legislative reports make it clear that these provisions are
solely intended to encourage generators to voluntarily
institute waste reduction programs on the basis of economic
practicability. As such, the amendments require only that
generators make a good faith effort to reduce wastes in light
of individual circumstances; judgments made by generators are
not subject to external regulatory action, nor do they create
civil or criminal liabilities. See, e.g.. Senate Environment
and Public Works Committee Report No. 284, 98th Cong., 1st
Sess. 66 (1983). Thus, from an enforcement perspective, EPA
will be concerned primarily with compliance with the certifi-
cation signatory requirements. 50 Fed. Reg. 28734 (July 15,
1985).
Waste minimization programs are strictly
voluntary at this point, but legal responsibilities for
generators could change in the near future. Although EPA
recommended in its October 1986 report that the consideration
of mandatory programs, including performance standards and
required management practices, be deferred until additional
data on hazardous waste generation and management could be
gathered and analyzed, the Agency has committed to report
back to Congress in December of 1990 on the desirability and
feasibility of a prescriptive approach. Furthermore, EPA has
stated that if mandatory controls are needed in the interim,
it will institute them under the authority that currently
exists under such provisions as Section 6 of the Toxic
Substances Control Act (TSCA). Report at pp. xxiii, 77.
EPA's short-term strategy includes: (1) publication of non-
binding guidelines to generators on what constitutes
acceptable waste minimization practices; (2) provision of
technical and informational assistance to generators;7 and
(3) encouragement of voluntary waste minimization concepts
Two senate bills (S.1331 and S.1429) have been intro-
duced in order to provide such assistance.
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within the review of new chemicals under TSCA Section 5.
Report at pp. xxiii-iv. EPA could also recommend legislative
amendments to Congress as part of the next RCRA reauthoriza-
tion expected in 1988, such as (1) prohibiting consideration
of certain types of waste management practices as waste
minimization (e.g., those practices that result in adverse
cross-media pollution transfers) ; (2) providing formal
guidance as to what may be certified as waste minimization;
and (3) requiring written support from generators who certify
that there is no economically practical alternative to waste
management practices of which the Agency has not approved.
Report at pp. xxiv-xxv.8
If EPA-recommended waste reduction techniques
are to become mandatory in the future, those companies that
invest in such techniques at an early stage will find the
transition easier. Therefore, as a practical matter, there
is a substantial incentive even under this voluntary program
for generators to conduct waste audits and implement programs
now. Generators may seek EPA clarification on waste mini-
mization practices by letter to the Agency. Report at p. 67.
A final liability consideration under the
waste minimization requirements deals with possible suits
against generators by persons alleging injury from improper
exposure to wastes produced by the generator. If the
defendant generator has not instituted waste reduction
measures in its plant, but the majority of its industry has
(either voluntarily or by law) , such non-compliance could
conceivably be used against the generator as evidence of
negligence. (See Section Ill.C.l.(b) for further discussion
of generator liability under common law.)
III. COMPLYING WITH WASTE TREATMENT AND MINIMIZATION
GENERATOR OPTIONS AND THE "LIABILITY HIER-
ARCHY*
Several management options exist for a generator
required to dispose of wastes in accordance with the HSWA
land disposal and waste minimization requirements, including:
(1) reducing waste at the source; (2) on-site recycling and
resource recovery; (3) off -site recycling and resource
8 Other groups are in strong support of such recommenda-
tions. See, for example, OTA Report, From Pollution to
Prevention? A Progress Report on Waste Reduction. June
1987; Biden, A New Direction for Environmental Policy;
Hazardous Wfr^te Prevention. Not Disposal. 17 ELR 10400,
10402, (October 1987). In addition, some states are
considering mandatory reductions. For example, a bill
pending in Massachusetts would require companies to
reduce their total inventory of hazardous wastes by 15
percent each year. 18 Envt. Rptr. 1588 (10-23-87).
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recovery; (4) on-site treatment and disposal of wastes (or
obtaining a variance from the land disposal restrictions and
disposing of wastes untreated); or (5) off-site treatment and
disposal of wastes (or obtaining a variance from the land
disposal restrictions and disposing of wastes untreated).
This section discusses these options in order of increasing
potential generator liability, and will highlight short and
long-term considerations important for generators intending
to use a specific option or combination of options.
A. OPTION ONE: SOURCE REDUCTION
As discussed previously, EPA has defined source
reduction as any action that reduces the amount of waste
exiting from a process. (EPA Report at p.7) Source reduc-
tion techniques include process modifications, feedstock
substitutions or improvements in feedstock purity, various
housekeeping and management practices, and increases in
machinery efficiency.
1. Liability considerations
Because source reduction is in effect a "waste
avoidance" technique that utilizes in-house practices to
reduce waste generation, there is very little, if any,
liability risk associated with this option (assuming proper
management and no leaks or spills within the facility).9
Coupled with potentially huge economic savings for a company,
the reduced liability aspects of source reduction can make it
an attractive compliance option for generators. However,
most products cannot be manufactured without producing some
hazardous wastes; therefore source reduction techniques will
usually have to be combined with other compliance options
such as recycling or treatment.
2. Other considerations
Other factors may present practical limita-
tions to source reduction and prevent a company from fully
utilizing this option. Such factors include lack of suffi-
cient capital to institute process changes, technical
barriers such as lack of suitable engineering information,
and regulatory barriers such as the possibility that the
Of course, any company that uses hazardous substances
must continue to comply with applicable provisions of
federal and state law governing the use of hazardous
substances, including, inter alia, the reporting and
notification requirements of Title HI of the Superfund
Amendments and Reauthorization Act of 1986 (SARA) and
the Hazard Comnunication Standard (HCS) of the Occupa-
tional Safety and Health Act (OSHA), and similar
statutory provisions.
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installation of new equipment will be considered "treatment"
under RCRA and require a treatment, storage, and disposal
facility (TSDF) permit (EPA Report at pp. x-xii).10
B. OPTION TWO: RECYCLING AND RESOURCE RECOVERY
A material is "recycled" if it is used, reused, or
reclaimed. 40 CFR §261.l(b)(7). A material is "used or
reused" if it is either employed as an ingredient in an
industrial process to make a product or employed in a
particular function or application as an effective substitute
for a commercial product. 40 CFR §261.l(c)(5). A material
is "reclaimed" if it is processed to recover a usable product
or if it is regenerated, such as regeneration of spent
solvents. 40 CFR §261.l(c)(4).
Some recycled materials are considered "solid
wastes" under RCRA § 6903(27) and therefore are subject to
RCRA regulation. The residues resulting from these recycled
materials are also regulated under RCRA unless they are
formally delisted under 40 C.F.R. § 260.22. 50 Fed. Reg. 619
(Jan. 4, 1985).
EPA determines whether a recycled material is a
RCRA solid waste by examining the nature of the material and
of the recycling activity involved. The Agency has identi-
fied five categories of "secondary materials," which include
spent materials, sludges, byproducts, commercial chemical
products and scrap metal. According to EPA these secondary
materials are RCRA solid waste when they are disposed of;
burned for energy recovery or used to produce a fuel;
reclaimed; or accumulated speculatively. 50 Fed. Reg. 618-
19, 664 (Jan. 4, 1985).
Secondary materials are not, however, considered
RCRA solid waste if they are: (1) used or reused as
ingredients or feedstocks in production processes without
first being reclaimed; (2) used or reused as effective sub-
stitutes for commercial products; or (3) returned to the
original primary production process in which they were
10 Regulatory barriers in other contexts are also not
uncommon. In some air pollution control districts, for
example, even process changes resulting in a net
reduction in air emissions may still trigger new source
review, including the requirements for purchasing
offsets and the installation of Best Available Control
Technology. See, e.g.. South Coast Air Quality
Management District Regulation XIII.
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generated without first being reclaimed ("closed-loop"
exception).11 40 CFR § 261.2(e).
Thus, EPA draws a distinction between wastes that
are discarded and ultimately recycled and those that are
recycled on-site in a continuous or ongoing manufacturing
process. The former EPA considers as RCRA solid wastes; the
latter are not solid wastes and therefore not regulated under
RCRA.
1. Liability considerations
Because some secondary materials and all waste
residues are still considered by EPA to be hazardous and
regulated under RCRA Subtitle C unless they meet the delist-
ing criteria of 40 CFR § 260.22, a generator who recycles its
wastes is subject to the same type (though perhaps not the
same degree) of liability risks as a generator who treats and
land disposes of its wastes without first recycling.12 (See
discussion in Section III.C.I below). Thus, a generator
recycling and disposing on-site must be concerned about
liability resulting from improper disposal of the residue.
For a generator recycling and disposing off-site, liability
could result under common law, RCRA, or CERCLA if the
transporter, recycler, or disposal facility mishandles the
11 In the recent decision of American Mining Congress v.
EPA, the D.C. Appellate Court ruled that materials used
or reused in an ongoing manufacturing or industrial
process are not subject to RCRA's jurisdiction, even if
these materials are reclaimed first. 26 ERC 1345
(July 31, 1987). The court explained that these
materials are not within RCRA's jurisdiction because
"they have not yet become part of the waste disposal
problem: rather, they are destined for beneficial reuse
or recycling in a continuous process by the generating
industry itself." Id. at 1352.
EPA's interpretation of the court's opinion and its
proposed amendments to rules affected by the opinion are
fHsnisfleri at 53 Fed. Reg. 519 (January 8, 1988).
12 In most circumstances, recycling will have a liability
advantage over treatment and disposal because the
residue resulting from recycling will be lower in volume
than unrecycled waste. Furthermore, the residue may be
less hazardous than its waste predecessor and therefore
easier to delist, or could be in a form that is easier
to dispose of and more resistant to leaching. In other
situations, however, a recycling or treatment process
could concentrate the hazardous constituents of a waste,
making the waste more toxic and difficult to dispose of.
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waste in a way that results in an unauthorized release of the
waste into the environment.
Furthermore, courts have made it clear that a
generator must monitor the activities of future possessors of
its wastes, including recyclers, in order to minimize the
risk of liability. This is true whether ownership of the
waste is transferred from the generator to the transporter,
recycler, or disposal company (U.S. v. Wade. 577 F. Supp.
1326 (E.D.Pa. 1983)), or the transaction between generator
and recycler is characterized as a "sale" of commercial goods
rather than an "arrangement" for disposal under CERCLA
§107(a)(3). U.S. v. A & F Materials. 582 F. Supp. 842, 845
(S.D. 111. 1984) (spent caustic solution sold by generator to
the highest bidder); U.S. v. Ward. 618 F.Supp. 884, 895
(E.D.N.C. 1985) (sale of PCB's by generator to a trans-
porter) ; N.Y. v. General Electric Co.. 592 F. Supp. 291, 297
(N.D. N.Y. 1984) (generator sold used transformer oil to a
dragway to be used as dragway owner saw fit). See general
discussion on generator liability in Section III.C.I below.
2. Other considerations
In addition to liability considerations, a
generator may be required to obtain permits in order to
recycle, an often costly and time-consuming process. (See
discussion on permitting difficulties in Section III.
C.2.(c) below). A generator shipping wastes off-site to be
recycled must comply with the applicable requirements of
40 C.F.R. Parts 262 and 263 and the notification require-
ments of RCRA § 3010. 40 C.F.R. § 261.6(b). Generators
recycling on-site (as well as any owner or operator of a
recycling facility) must also comply with all applicable
requirements of 40 C.F.R. Sections 265.71 and 265.72 and
RCRA § 3010 notification requirements. If the recyclable
materials are stored prior to recycling, all applicable
provisions at 40 C.F.R. Parts 264 (subparts A-L), 265
(subparts A-L), 266, 270, and 124 and RCRA § 3010 notifica-
tion requirements must be followed. 40 C.F.R. § 261.6(c)(l)
and (2).
Furthermore, logistical considerations may
prevent a generator from recycling wastes. For example, even
if the waste is technically recyclable, it may be difficult
to accumulate sufficient quantities on-site to make the
process economically attractive, or it may be difficult to
synchronize generator and recycler needs.
C. OPTION THREE: TREATMENT AND LAND DISPOSAL
A third option available to a hazardous waste
generator is to treat the waste to meet RCRA § 3004 treatment
standards and then dispose of the residual waste in a RCRA
-------
permitted landfill or other disposal facility (or obtain a
variance from the land disposal restrictions and dispose of
the waste untreated). If the waste volume and/or toxicity
has not been reduced through any intermediate processing
techniques prior to treatment and disposal (i.e., the waste
is shipped directly from its point of generation to the TSD
facility.) , this disposal method can be the most expensive and
liability - prone option.13 Generators who are responsible
for the disposal of hazardous wastes or waste residues must
therefore make efforts to minimize RCRA, CERCLA, and common
law liability risks. Some of these protective steps will be
discussed during the presentation.
1. Liability considerations
a. Statutory liability
(1) RCRA
Under RCRA §7003, codified at 42 U.S.C. §6973,
the government is authorized to initiate injunctive action or
issue remedial orders when past or present handling, storage,
treatment, transportation or disposal of any solid or
hazardous waste may present an imminent and substantial
endangerment to health or the environment.
The HSWA 1984 amendments to this section make
it clear that past and present generators who have con-
tributed to the site are among those potentially liable.
Similarly, courts have interpreted §7003 to apply retro-
actively to past and present generators, and where the injury
occurring is indivisible, to impose joint and several
liability. In addition, liability can be strictly imposed
without fault or negligence on the part of the generator; to
establish a prima facie ca 3 of liability, the government
need only show: (1) that ae conditions at the site present
an imminent and substantial endangerment} (2) that the
endangerment stems from the handling, storage, treatment,
transportation, or disposal of any solid or hazardous waste;
and (3) that the defendant has contributed or is contributing
to such handling, storage, treatment, transportation, or
disposal. See, e.g., U.S. v. Northeastern Pharmaceutical and
Chemical Co.. 810 F.2d 726 (8th Cir. 1986); U.S. v. Bliss.
667 F. Supp. 1298 (E.D. Mo. 1987); U.S. v. Conservation
Chemical Co.r 619 F. Supp. 162 (W.D. Mo. 1985). Thus, a non-
13 This would obviously not be the case if the generator
could delist its waste after treatment and dispose of it
under RCRA Subtitle D. Then direct treatment and
could be an attractive option from both an
economic and liability standpoint. RCRA delisting may
not protect the generator from CERCLA liability,
however.
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negligent generator could be held strictly and solely liable
under RCRA §7003 for releases or spills caused by its
transporter or treatment and disposal facility.
In addition, RCRA §3008(d), codified at 42
U.S.C. §6928, imposes criminal penalties upon any person who
knowingly transports or causes to be transported or knowingly
treats, stores or disposes of any RCRA hazardous waste
without a permit or in non-compliance with the manifest
system. Violation of this section can result in fines of up
to $50,000 per day of violation or imprisonment of up to 2-5
years. In one case where a generator was found guilty of
knowingly shipping wastes to an unlicensed recycling
facility, the court concluded that knowledge does not require
certainty, and that a defendant acts knowingly if he
willfully fails to determine the permit status of the
facility. U.S. v. Haves International Corp.. 786 F.2d 1499,
1504 (llth Cir. 1986) (citing Bovce Motor Lines v. U.S.. 342
U.S. 337 (1952)).
(2) CERCLA
Generators can also be held liable for
corrective action and response costs under CERCLA Sections
106 and 107. 42 U.S.C. §§9606-07. Section 106 allows the
government, through the use of administrative orders and
judicial relief, to abate an "imminent and substantial"
threat to the public health which results from an actual or
threatened release of a hazardous substance. CERCLA §107
allows the government to recover response costs for cleanup
of wastes from four classes of defendants: current owners of
a disposal site, past owners of a disposal site, generators
who arrange for disposal at a site, and transporters of waste
to a site from which the waste is released or is threatened
to be released.
Courts have interpreted these provisions of
CERCLA broadly, and have determined that liability under them
is strict, joint and several. Furthermore, the proof of
causation needed to impose liability is minimal.-1-4 See,
e.g., U.S. v. Wade. 577 F. Supp. 1326 (E.D.Pa. 1983); U.S. v.
Price. 577 F. Supp. 1103 (D. N.J. 1983); U.S. v. Chem-Dvne
Corp.. 572 F. Supp. 802 (S.D. Ohio 1983); U.S. V.
Northeastern Pharmaceutical and Chemical Co.. 810 F.2d 726
(8th Cir. 1986) ; U.S. v. A&F Materials Co.. Inc.. 578 F.
Supp. 1249 (S.D. 111. 1984); U.S. v. Conservation Chemical
Co.. 619 F. Supp. 162 (W.D. Mo. 1985). Once the requisite
14 Congress affirmed the courts' interpretation of CERCLA
in the legislative history to the Superfund Amendments
and Reauthorization Act of 1986 (SARA). See, e.g., H.R.
Rep. No. 253, 99th Cong., 1st Sess., pt. 3 at 15 (1985)
(Judiciary Ccratiittee).
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nexis is established, the burden of proof is on the defendant
to show that it meets one of the affirmative defenses set out
in CERCLA § 107(b).
The government therefore is not required to
"fingerprint" a generator's waste (i.e., prove that that
particular generator's waste caused the damage), but need
only show that the generator: (1) disposed of its hazardous
substances (2) at a facility which now contains hazardous
substances of the sort disposed of by the generator and
(3) there is a release of that or some other type of hazar-
dous substance (4) which causes the incurrence of response
costs. Wade at 1333. See also Violet v. Picillo. No. 83-
0787P, slip op. (D.R.I. Nov. 10, 1986); U.S. v. Miami Drum
Services. Inc.. No. 85-0038, slip op. (S.D. Fla. Dec. 12,
1986). Because CERCLA §107(a)(3) only requires that the
generator "arrange for" disposal "at any facility owned or
operated by another party" from which there is a release,
many courts have rejected the notion that a generator must
have chosen the site at which its wastes are actually
disposed in order to incur liability. See Wade at 1333 n.3;
Picillo at 8; Conservation Chemical Co. at 234; U.S. v. Ward.
618 F. Supp. 884, 895 (E.D. N.C. 1985). Thus, a nonnegligent
generator can be held liable under CERCLA §§106 and 107 for
releases caused by the actions of its transporter or
treatment and disposal facility (even if it is not a facility
that the generator selected).
Furthermore, because the person arranging for
disposal is not required under CERCLA to actually own or
possess the hazardous waste or the facility from which it is
removed for disposal, courts have interpreted the term
"person" to include both the generator corporation and
individual employees of the generator corporation. Thus,
those persons that actively exercise control over the place
and manner of disposal can be potentially liable under the
statute. See U.S. v.Northeastern Pharmaceutical & Chemical
Co.. 579 F. Supp. 823, 847 (W.D. Mo. 1984), aff'd. 810 F. 2d
726 (8th Cir. 1986) (vice president and immediate supervisor
of the facility, as well as president of the facility, held
liable); U.S. v. Bliss. 667 F. Supp. 1298 (E.D. Mo. 1987)
(waste broker held liable); Jersey City Redevelopment Author-
ity v. PPG Industries. 655 F. Supp. 1257 (D.N.J. 1987)
(defendant company within the scope of CERCLA §107 when it
arranged to sell mud from its property as fill, even though
company was unaware that the mud was contaminated with
hazardous chromium).15
b. Common law liability
15 The New Jersey court did note that lack of knowledge
could possibly be an affirmative defense.
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A plaintiff bringing suit against a
generator for injury resulting from improper management or
disposal of hazardous wastes could base the claim on five
possible common law theories: negligence, trespass,
nuisance, strict liability, and vicarious liability. See J.
DiBenedetto, Generator Liability Under the Common Law and
Federal and State Statutes. 39 Bus. Law. 611 (1984). Because
of the difficulties of proving causation under negligence,
the limitation of trespass solely to injuries to land, and
the burden of establishing the equities in one's favor under
nuisance law, a plaintiff is most likely to be successful
under theories of either strict or vicarious liability.
Under strict liability, a generator could
be held liable on the ground that it is making a "non-natural"
use of its land (the Rylands approach) or on the ground that
it is engaging in an "abnormally dangerous" activity (the
Restatement approach). Courts that have held generators
liable under a strict liability theory have analogized to
strict products liability and have justified it on the basis
that the generator economically benefits from the activity
and therefore should bear the costs of injury. See, e.g.,
Citv of Bridaeton v. British Petroleum Oil. Inc.. 369 A.2d 49
(N.J. Super. Ct. Law Div. 1976), State of New Jersey Dep't of
Environmental Protection v. Ventron Corp.. 463 A.2d 893 (N.J.
1983). Before a successful claim can be made under strict
liability, however, the plaintiff must show that the
generator's activity is inherently or abnormally dangerous
and prove a causal connection between the generator's
activity and the harm incurred. DiBenedetto at 621.
Under a vicarious liability theory, a
plaintiff could claim that the generator should be held
liable for improper management of wastes by its transporter
or disposal facility because the generator arranged for the
disposal. The plaintiff would have to prove however, that
the work contracted for between the generator and the
transporter or disposal facility is inherently or intrin-
sically dangerous or likely to result in a nuisance or a
trespass. DiBenedetto at 622.
c. Recommendations
Because a generator faces continuing liability
risks for hazardous waste releases, it should attempt to
minimize these risks when dealing with transporters,
recylers, and treatment, storage and disposal (TSD)
facilities. Some practical suggestions follow.
First, generators should exercise due care in
selecting a transporter, recycler or TSD facility. In
choosing a transporter, the generator should verify permits,
licenses and equipment and require the transporter to post a
security or performance bond. In choosing a recycler or TSD
-------
facility, the generator should be satisfied that the facility
has the capacity to handle its waste, has the proper state
and federal permits, is in good standing with the appropriate
environmental agencies, and has sufficient insurance cover-
age. A generator may also want to conduct an on-site
evaluation of the plant and talk with other customers about
their experiences. See R.T. Murphy, Generator Responsibil-
ities in Selecting Treatment. Storage, and Disposal Services.
39 BUS. Law 309 (1983).
Second, a generator should monitor its wastes.
With respect to transporters, a generator should make sure
that it receives a manifest copy to ensure that the waste has
reached the proper disposal facility. In addition, some
companies periodically follow their transporter's vehicle to
make certain that the waste is actually delivered to the
proper destination. Murphy at 313. With respect to a
recycler or TSD facility, monitoring means ensuring that
permits and insurance coverage are current, and verifying
that wastes are treated to meet the land disposal treatment
standards prior to disposal.
Finally, generators should protect themselves
through indemnity agreements with transporters, recyclers or
TSD facilities. Any contract for transport, treatment or
disposal should precisely state that the indemnitor (trans-
porter, recycler or TSD facility) will indemnify the genera-
tor against liability resulting from strict liability or the
indemnitor's negligent actions, or from failure to comply
with statutes, ordinances, regulations (including treatment
standards), or permit conditions. In accepting an indemnity,
of course, the generator should investigate the indemnitor's
financial resources, to ensure that the indemnity is of
value. In addition, the generator should consider a contract
provision requiring the transporter or facility to carry
environmental impairment insurance for the protection of both
parties (waiving subrogation) and naming the generator as an
additional insured party. See C.F. Lettow and J.T. Byam,
Generator - Disposer Indemnity Agreements. 39 Bus. Law. 315
(1983) .
2. Other considerations
a. Obtaining an exemption or variance from
the land disposal restrictions
A generator could apply for an exemption or
variance from the land disposal treatment standards (see
discussion under section II.A.(3) above) and continue to
dispose of its wastes untreated. In order to obtain an
exemption, a generator must demonstrate to a reasonable
degree of certainty that no hazardous constituents will
migrate from the disposal unit. Initially EPA proposed that
the applicant need only show that any migration from the
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disposal site would be at concentrations that did not pose a
threat to human health and the environment. The Agency
changed its position in promulgating its final rule, however,
and now requires a showing of no migration whatsoever. The
Agency has acknowledged that the new "no migration" standard
is more stringent, and it expects relatively few cases in
which the demonstration will be made. 51 Fed. Reg. 40578
(November 7, 1986).
Alternatively, a generator could obtain a
variance from the land disposal restrictions by showing that
it has entered into a binding contract to construct or
otherwise provide alternative capacity that cannot reasonably
be made available by the applicable restriction date due to
circumstances beyond the generator's control. Such a solu-
tion is temporary, however, as an extension cannot be granted
beyond two years. Furthermore, treatment, storage and
disposal facilities may be reluctant to accept wastes
purported to be exempt from the treatment standards because
they cannot easily verify that such is the case. A final
consideration in obtaining a variance from EPA is that state
law may impose more stringent treatment standards or even
prohibit variances altogether based on regional capacity
determinations.
b. Off-site treatment and disposal: capacity
limitations
A generator treating and disposing of wastes off-
site will have to consider short-term and perhaps even
permanent treatment capacity shortages that have resulted
from implementation of the land disposal restrictions and
siting and permitting difficulties encountered by new
facilities. Such shortages, along with more stringent design
and construction standards for RCRA-approved landfills, are
likely to drive up the costs of treatment and disposal
significantly. 16
EPA has already identified shortages of treatment
capacity for solvent and dioxin wastes. For solvents, the
Agency estimates a shortfall of approximately 378 million
gallons per year for wastewater treatment capacity and 42.7
million gallons per year for incineration. 51 Fed. Reg.
40614 (November 7, 1986). The Agency concluded that there
are currently four wastewater treatment facilities and twelve
16 EPA estimates that these new requirements have
already pushed the price of land disposal from $10-
$15 per metric ton in the early 1970's to $240 per
metric ton. EPA Report at 15.
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commercial incinerator facilities available to accept solvent
wastes. 14.17
Whether capacity shortages will continue into the
future depends upon how quickly the marketplace can install
more capacity to respond to the land disposal restrictions
and at what cost. Two significant market impediments to the
siting of new facilities are public opposition to the
construction of new waste sites and the financial liability
requirements applicants must meet in order to secure a TSDF
permit. Public concern about the risks posed by hazardous
wastes creates a "not in my community" syndrome, and leads to
opposition against local transportation and disposal of the
wastes. Typically such resistance is extremely difficult to
overcome.
Furthermore, assuming that a facility receives
construction approval, a TSDF operator must comply with
extensive RCRA permit requirements such as groundwater
monitoring, minimum technological construction requirements,
preparedness and prevention requirements, recordkeeping and
reporting requirements, and post-closure monitoring require-
ments. The permit process is costly and usually takes several
years to complete. Applicants are also subject to the
corrective action provisions of RCRA §3004(u) and (v), which
require corrective action for all releases of hazardous waste
constituents from any unit at a TSD facility seeking a permit
regardless of when the release occurred.
Finally, a TSDF applicant must demonstrate finan-
cial responsibility for bodily injury and property damage
arising from both sudden accidental and nonsudden accidental
occurrences. This requirement can be satisfied through
either liability insurance, corporate guarantee or a combina-
tion of the two. RCRA §3004(a)(6) and 3005(e)(2); 40 C.F.R.
§264.147(a) and (b). EPA has concluded that units at over
1,000 of 1,551 land disposal facilities have lost RCRA
interim status because of their inability to certify compli-
ance with these financial responsibility requirements. EPA
Report at 23. In fact unavailability of adequate insurance
coverage is the primary reason that TSDF owners and operators
are unable to comply. Because insurers consider pollution-
related risks to be so high, they have decreased the types of
insurance available to TSDF owners and operators while
17 One recent development that may help to alleviate
capacity problems is the new mobile treatment unit
("MTU") permit program, which is expected to be
finalized by EPA in early 1988. 52 Fed. Reg. 20914
(June 3, 1987). An MTU permit would allow
commercial companies to treat wastes at the
generator's site rather than requiring transport of
the wastes to a treatment facility.
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substantially raising the costs of obtaining insurance.
Policy premiums have increased 50 to 300 percent, and many
companies have difficulty obtaining coverage at all. Cover-
age for environmental claims (at least for those based on
sudden and accidental releases) was previously available to
TSDF owners and operators to protect themselves in part from
third party and government claims. However, such coverage is
now generally unavailable. EPA Report at 22-23.
The above factors public opposition to new TSD
facilities, costly and time-consuming permit requirements,
and difficulties in obtaining adequate liability insurance
will combine to further prolong the treatment and disposal
capacity shortage that hazardous waste generators are
currently experiencing.
c. On-site treatment and disposal:
permitting difficulties
A generator may consider on-site treatment and
disposal of wastes for the following reasons: (1) to limit
transportation and disposal costs; (2) to reduce the risk of
incurring cleanup costs under RCRA or CERCLA for a hazardous
waste release; and (3) to assure future treatment and
disposal capacity. While on-site treatment and disposal may
be an economically feasible alternative, a generator applying
for an on-site permit will face the same difficulties as
commercial TSDF applicants, including public opposition and
substantial permitting and financial responsibility require-
ments .
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Session II
Source Reduction
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Equipment Cleaning
Carl Fromm
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MINIMIZATION OF PROCESS EQUIPMENT CLEANING WASTE
by
Carl H. Fromm
Srinivas Budaraju
Susanne A. Cordery
Jacobs Engineering Group Inc.
HTM Division
251 South Lake Avenue
Pasadena, California 91101
ABSTRACT
The waste associated with cleaning of process equipment is probably a significant
contributor to the total waste volume generated by industry. This paper addresses the
following aspects related to equipment cleaning waste generation:
o Review of reasons for cleaning process equipment
o Reduction of cleaning frequency
o Reduction of quantity and toxicity of cleaning waste
o Costs associated with cleaning
Equipment cleaning techniques, media, and their applications are reviewed. Reduction
of cleaning frequency is addressed in terms of inhibition of fouling through proper
equipment design and operation, maximization of equipment dedication, proper
production scheduling, and avoidance of unnecessary cleaning. When cleaning has to
be performed, the quantity and toxicity of resulting waste can be minimized by
reducing clingage, amount of cleaning solution, choice of less toxic cleaning solution,
cleaning solution reuse, and other approaches. Application examples are given to
illustrate each approach.
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INTRODUCTION
The current costs of waste disposal and treatment, regulatory pressure, and concerns
about legal liabilities have been forcing U.S. industries to scrutinize their hazardous
waste generation practices i/. A primary objective of these efforts has been to
minimize waste generation, i.e. to reduce the quantity and toxicity of the waste.
Of the many industrial waste-generating operations, process equipment cleaning (PEC)
is nearly universal in its application, as it is practiced in all segments of manu-
facturing industry. PEC is of particular importance for discrete processes such as
batch reactions, compounding, surface coating operations, etc. This is because the
cleaning frequency for discrete processes is generally much higher than for continuous
processes. However, this does not mean that cleanup wastes from continuous
processes can be ignored. Disposal of sludges from cleaning of heat exchanger fouling
deposits, for example, is often of concern to the operators of petroleum refining,
petrochemical and chemical process facilities.
The intent of this paper is to review basic waste minimization strategies applicable to
cleaning operations. The intent is to provide a structured classification of such
strategies presented in the form of a prototype checklist which can be used to help
focus and plan a concerted attack on waste.
WHY EQUFMENT IS CLEANED
Equipment cleaning is a maintenance function typically performed for the following
reasons:
to restore or maintain the operating efficiency of equipment, e.g., to
restore adequate heat transfer rate and low pressure drop in heat
exchangers.
to avoid or limit product contamination, e.g., when a paint mix tank needs
to be cleaned between batches of varying paint formulations.
to minimize corrosion and extend equipment lifetime.
to allow for inspection and repair of equipment.
to improve appearance (exterior surfaces only).
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The need for cleaning 13 a direct consequence of deposits formed on the surfaces
exposed to the process environment. Some of the major routes and origins of deposit
formation are summarized in Table 1 along with descriptions and some examples.
Understanding how and why the deposits are formed is a critical first step in any
waste minimization effort. It is an especially important aspect for equipment and
process designers, because the need for equipment cleaning can often be reduced or
eliminated through design modifications at minimal expense during the design stage.
A common sense approach to minimizing waste from equipment cleaning operations is
to pose and answer the following sequence of questions:
why is the deposit present?
how can cleaning be curtailed or avoided (i.e., cleaning frequency
reduced)?
when cleaning is necessary, which cleaning method and medium will
generate the least amount of least toxic waste?
Sections below address major aspects related to the last two questions.
REDUCTION OF CLEANING FREQUENCY
Generally, the need for cleaning can be reduced or avoided altogether by the
application of the following measures:
inhibition of fouling or deposit formation rate.
maximizing dedication of process equipment to a single formulation or
function.
proper production campaign scheduling.
avoidance of unnecessary cleaning.
Inhibition of fouling is of particular importance in heat transfer applications where it
can be accomplished through a variety of means, including use of smooth heat transfer
surfaces, lower film temperatures, increased turbulence, control of fouling precursors
and proper choice of exchanger type.
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TABLE 1. TYPICAL ROUTES AND ORIGINS OF DEPOSIT
FORMATION IN PROCESS EQUIPMENT
Route/Origin
Description
Crystallization
Sedimentation
Chemical reactions and polymerization
High temperature coking
Corrosion
Bacterial growth (biofouling)
Clingage
(of importance to solvent
cleaning applications)
Major problem in evaporators and
crystalizers (e.g. very frequent in
food processing).
Major problem in petroleum refinery
crude unit desalters and oil storage
tanks. Also present in cooling tower
basins.
Buildup on the internal reactor sur-
faces are often encountered (e.g. allyl
chloride synthesis). Also of importance
in crude oil storage tanks.
Carbonaceous material depositing on
walls of furance tubes (e.g. furnace
for ethylene chloride pyrolysis).
Common problem in heat exchangers in
chemicals and allied products industry.
Major problem on cooling-water-side
of heat exchangers in electric power
production.
Residual coat of process liquid left
after drainage; major problem in
reactors and mixers in the paint
manufacturing industry and generally
in all high-viscosity liquid transfer
operations.
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The use of smooth heat exchanger surfaces results in lowering the adhesion of the
deposit or its precursor to the surface. Application of electropolished stainless steel
tubes in a forced circulation evaporator used in black liquor service in a paper mill
resulted in a dramatic reduction of cleaning frequency from once a week to once a
year 2/. Smooth non-stick surfaces can also be provided by Teflon (a registered
trademark of E.I. Dupont de Nemours <5e Co.). Teflon heat exchanger designs are
commercially available, as are designs utilizing Teflon coated steel. In a separate
application, condensers using Teflon-coated tubes have been shown to drastically
reduce fouling and resist corrosion while maintaining high thermal efficiency. The
higher cost of material was weighed against reduced energy cost to show a 69 percent
return on investment in the first year before tax 21/. if reduced cleaning costs were
to be added, the ROI would have been higher.
The rate of heat exchanger fouling in a given service is dependent upon fluid velocity
and, quite often, on film temperature. Film temperature controls the speed of
chemical reactions which result in deposit-forming compounds while fluid velocity
~ols the shear rate at the fluid-deposit interface.
, lowering the temperature of the heating medium and increasing the fluid
vt. ty (e.g. by recirculation) can produce a desired reduction of the fouling rate. An
economic trade-off analysis between the increase in pumping cost and the decrease in
the cost of cleaning and other possible savings appears warranted in investigations
relating the degree of oversizing to cleaning waste generation. A general review of
thermal and hydrodynamic aspects of heat exchanger fouling was provided by
Knudsen !/.
Control of deposit precursors is often an obvious practical consideration. Proper
maintenance of cooling water quality in open circulating systems is of paramount
importance to water-side heat exchanger fouling. Control of hardness, pH, corrosivity
and biofouling tendency is accomplished through careful monitoring of water
quality !£/. In particular, biocides added in treatment must propagate the entire
cooling fluid path in order to be deposited and function at all locations in the
exchanger; and acid feed equipment to maintain the pH in the non-scaling range of
6 to 7 must be reliable or else rapid scaling or corrosion problems occur !'.
The choice of heat exchanger type can influence cleaning frequency. For example,
spiral plate exchangers are often specified over other designs in fermentation plants,
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owing to the ease of solid resuspension, absence of pockets, and non-plugging
characteristics. Rod baffle design provides more effective shell-side turbulence at
lower pressure drop compared to a more conventional segmented baffle design.
Therefore, the rod baffle design can be expected to exhibit superior shell-side fouling
characteristics.
Slowing down the rate of deposit formation is not limited to heat exchangers, but also
is important for other types of equipment. For example, crude oil's exposure to
atmospheric oxygen can cause formation of gums and resins during long exposure
periods inside storage tanks. The use of floating roof tanks or inert gas blanketing has
been suggested as a way to reduce tank deposit buildup ^/. Similarly, in paint
manufacturing, exposure to air causes formation of solid films that adhere strongly to
the internal surface of the mixers. This can be avoided by using closed storage and
transfer systems, as evidenced by experience at Ford Motor Company. At Ford, the
paint storage and transfer system was enclosed and redesigned for full recirculation
resulting in less frequent and easier cleanups and an improvement of paint quality >/.
Other applications of fouling inhibition include coating of reactor internals with
special chemicals to prevent scale formation. These practices have been used in the
suspension polymerization process for polyvinyl chloride £/.
Maximizing dedication of process equipment to a single process function or
formulation will reduce cleaning frequency, as the frequency of switching to different
formulations will diminish. Maximum dedication means either converting from a batch
to a continuous process or using the equipment intermittently just for one formulation.
Historically, the changeover from batch or cyclic to continuous operations has been
common in the chemical industry, owing to increased product demand, increased labor
costs and technological progress. The advantages of the continuous process over batch
include the ease of automation and control (which minimizes human error leading to
inferior product quality) and lower labor requirements.
The choice between the continuous or batch mode is governed primarily by production
volume and related trade-offs between capital and operating costs. The batch process
is advantageous in situations where production volumes are small and product diversity
large. Batch processes have proven advantageous even for certain large volume
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products, such as, neoprene rubber and phenolic resins, where continuous alternatives
were developed but failed to find wide application L§/.
Dedicating a piece of equipment to a single formulation in the batch process means
that the equipment remains dormant between individual production campaigns.
Cleaning after each campaign can be avoided provided that materials left in the
equipment do not deteriorate with time or corrode the internals. Also, the cost
penalties associated with equipment under-utilization must be outweighed by cleaning
costs incurred when the equipment is used with more than one formulation.
Proper production scheduling is a commonly invoked method to decrease cleaning
frequency. Equipment utilization strategies and the resulting production schedules
should be derived through optimization analysis, where the objective is to meet the
desired production goals with due consideration of such constraints as available
equipment, cost of turnaround, labor availability, storage, etc. Meeting production
goals is to be accomplished with minimum cost, which includes minimization of
cleaning frequency. A general review of optimum strategy formulation was given by
Peters and Timmerhaus 2'.
However, in a typical situation a formal optimization analysis is not used often.
Rather, a common-sense approach to production scheduling is used based on trial-and-
error preparation of production bar-charts. To reduce cleaning waste, it is generally
desirable to schedule long campaign runs, as opposed to short and more frequent runs.
Production schedulers now must be aware of the current waste disposal costs, an
aspect that previously could have been ignored.
Avoidance of unnecessary cleaning should be one of the goals of waste minimization
audits. At times, equipment cleaning is performed routinely with little or no
consideration of the rationale for the cleaning activity. An actual case is known
where a ball mill was used periodically to wet-grind a certain powder. The ball mill
with corrosion-proof internals was totally dedicated to the same formulation, a stable
mixture of inorganic powders. Yet, the ball mill was cleaned after each use for no
apparent reason. Upon questioning, the only justification provided was that the other
non-dedicated ball mills at the facility were cleaned after every use.
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REDUCTION OF QUANTITY AND TOXICITY OF CLEANUP WASTE
When cleaning has to be performed, it should be performed effectively with minimal
generation of waste. Typical considerations include the choice of cleaning medium,
cleaning technique and waste disposal option. A brief overview of these choices (with
the exception of waste disposal), is provided in the following paragraphs.
A distinction can be made between chemical and mechanical cleaning. Chemical
cleaning requires the use of substances such as those shown in Table 2 which are
employed to chemically attack the deposits and render them either solvent or water-
soluble. The basic reaction types include oxidation, reduction, chelation or conversion
of insoluble oxides into soluble salts. Cleaning formulations also include surfactants to
lower surface tension of solution to allow for faster penetration and breakup of
deposits.
Physical or mechanical cleaning relies on breaking the adhesion of the deposit to a
surface using mechanical devices, such as scrapers, squeegees, rags, drag lines, "pigs",
lances or through the use of high velocity water jets (hydroblasting). Often
mechanical and chemical cleaning are combined, e.g., when high velocity jets are
employed with caustic solutions to attack deposits in paint mix tanks.
According to a classification developed by Loucks 12', six separate cleaning
techniques are distinguished:
fill-and-empty technique
circulation technique
"flow over" technique .
gas propel technique
process simulation technique
onstream cleaning technique
In the "fill-and-empty" technique, a process vessel is isolated from other equipment
and filled with an appropriate cleaning solution. The solution can be heated and
agitated and, after a period of 4 to 8 hours it is drained. Rinse-water or diluted alkali
or acid solutions are then used to remove residual cleaning chemical. Drained
chemicals and subsequent rinses are either reused, treated, recycled or land-filled
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TABLE 2. SOME CHEMICAL CLEANING COMPOUNDS AND THEIR USAGE
Cleaning Compound
Chemical Action
Usage
Remarks
Hydrochloric Acid
Sulfuric Acid
Nitric Acid
Hydrofluoric Acid
Sulfamic Acid
Citric Acid
Caustic Soda, Soda Ash
Ammonia
Ethylene Diamine
Tetra-Acetate (EOTA)
Dissolves most water scales
and corrosion products
Dissolves most corrosion
products
Same as HC1
Dissolves silicate deposits
Dissolves calcium salts
Dissolves iron oxides
Dissolves oil and grease
Forms soluble complexes with
copper ions
Dissolves water scales at
alkaline pH's
Used on boilers, heat
exchangers, pipelines, etc.
Limited use
Used for stainless steel
and aluminum
Used as an additive to HC1
(as ammonium bifluoride)
Used as an additive to HC1
Used mostly to clean boilers;
frequently with added ammonia
and oxidizers
Used to remove oil and grease
before acid cleaning and to
neutralize the acid after
cleaning
Used to remove copper from
large boilers
Corrosive to steel; tempera-
tures must be below 175 F
Cannot remove water
scales
Cannot be used for copper
and ferrous alloys
Very dangerous to handle
Easy to handle; soluble
calcium salts
Not good for water scale
removal
Dangerous to handle
Needs to be handled
carefully
Used for cleaning water systems Expensive
without shutdown
Source: References (10), (20).
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depending on their composition and the availability of disposal options at the
particular site. The method uses large quantities of chemicals and requires substantial
downtime. It is typically applicable to small vessels, tanks or heat exchangers.
In the "circulation" technique, the vessel is filled with cleaning solution to an overflow
and allowed to stand for a short time period, after which the solution is circulated
with an auxiliary pump. Fresh make-up solution can be pumped in if used solution is
withdrawn. In boilers, nitrogen gas is used to provide agitation for more effective
scale removal.
The "flow over" technique consists of spraying the solution onto the surface. It is
applicable to large tanks where cleaning by filling or recirculation would require
excessive quantities of cleaning solution. Extra safety precautions are usually
necessary.
The "gas propel" technique utilizes cleaning agents that are not overly corrosive at
higher temperatures when steam is used to propel them through the system. This
technique is useful for pipelines, where inhibited organic acids or chelants are
entrained into a flow of steam which carries the liquid drops and solids debris through
hydraulic obstacles of the system.
The "process simulation" technique is applied to equipment that is easily fouled and
where spare parallel units are provided. Fouled equipment is cleaned by simulated
process operation, where the equipment is isolated, drained of process fluid and filled
with the cleaning solution using process pumps and controls to maintain flow and
temperature. An example is removal of iron oxide and copper deposits from high
pressure steam generators using aramoniated EDTA solution.
The "onstream cleaning" technique is probably the most preferable method, as it relies
on process fluid to do the cleaning during normal operation. Often auxiliary
mechanical devices are used along with additives, such as EDTA or acids to promote
deposit removal. This technique is used for cleaning reactor jackets, gas compression
station engines, heat exchangers, and other equipment. In-service cleaning of large
circulating cooling water systems is often done through intermittent pH swing to the
acid side of neutral and back again. Among many mechanical devices used in
conjunction with onstream cleaning, one could mention ram valves for rodding out
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plugged nozzles and moveable heat exchanger tube inserts propelled by reversing
process fluid il/. In a separate example, the use of fluidized beds of inert solids (e.g.,
sand) was found useful in heat transfer applications characterized by extreme fouling,
such as heat recovery from geothermal brines. Solid particles constantly abrade the
deposit away from the heat transfer surface, maintaining high transfer rates.
The choice of cleaning method and media, apart from cost, should also be based on the
following environmental considerations:
minimize the amount of cleaning solution used;
choose the medium ultimately resulting in the least toxic waste;
determine ahead of time how the cleaning waste is going to be disposed of.
The use of chemical cleaning (e.g., with mineral or organic acids) results in
appreciable quantities of hazardous cleaning wastes which need to be treated prior to
disposal. As appropriate treatment facilities are not available onsite in every case,
mechanical cleaning and onstream cleaning appear preferable to chemical cleaning.
According to information obtained from various cleaning contractors, these factors
are gaining recognition as the recent trend has been more toward hydroblasting and
onstream cleaning and away from chemical cleaning. This was attributed to the rising
costs of waste disposal and treatment.
When chemical cleaning is unavoidable, the least toxic medium should be chosen; for
example, an alkaline cleaner would be preferable over a halogenated solvent. How-
ever, if the toxicity of the "soil" to be removed is the controlling factor, the cleaning
agent with a higher potential for recovery and reuse should be used.
An attractive alternative to those cleaning methods that require disassembly of
equipment for cleaning, is a clean-in-place (CIP) system. The system is composed of
tanks, heat exchangers, filters, pumps, piping and instrumentation permanently
installed as an auxiliary system designed to circulate a controlled inventory of
cleaning solution through isolated process equipment often using spray manifolds or
liquid jet nozzles inside production vessels. The CIP systems generally reduce the
usage of cleaning medium. They are especially effective when coupled with high
velocity automated jet manifolds and staged counter-current rinsing; an 80 to 90
percent reduction in aqueous waste was achieved by paint manufacturers after
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installing high pressure spray nozzles for tank rinsing !£/. CIP systems are popular in
food, pharmaceutical and paint industries; however they are utilized less frequently in
the chemical processing industry I2/.
Reuse of cleaning solutions is common in CIP systems. In general, reuse of cleaning
solutions is highly desirable, especially if they can be utilized as part of formulation.
For example, a considerable reduction in reactor cleanup waste was achieved by
Borden Chemical where a two-step rinse sequence was applied to a batch kettle
arrangement used for phenolic resin synthesis. The first rinse used a small amount of
water generating a concentrated stream which could be recycled to the process. The
second full volume rinse generated wastewater with a much lower content of toxic
material than a previously used single rinse method M'. Other examples include reuse
of rinsewater from latex tank cleaning as part of latex formulation in the paint
industry II' and use of warm oil for flushing the deposits out from crude oil storage
tanks in an oil refinery, followed by solids separation in the slop oil system I£'.
The preceding sections were concerned with reduction of cleaning frequency and with
the choice of the least waste-intensive cleaning methodology. There is a related, but
independent aspect of cleaning waste reduction, i.e., reduction of clingage. As
explained previously, clingage is the amount of process material left inside the vessel
or other equipment after draining. In operations involving viscous fluids, such as paint
manufacturing and resin compounding, clingage is an important consideration as it not
only results in waste which is expensive to dispose of, but also represents a direct loss
of product or raw material.
To reduce clingage, the following measures should be considered:
provision of adequate drainage time;
use of low-adherence surfaces, e.g., fluorocarbon or electropolished steel;
use of mechanical wall wipers (dual shaft mixers);
use of manual wipers or squeegees;
choice of square cylindrical or spherical geometry to minimize wetted
surface;
rotation of agitator after batch dumping to reduce clingage on the blade.
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All of the above measures are self-explanatory and do not require elaboration. Most
are practiced extensively throughout industry. The use of tank linings as a means of
reducing adherence and preventing corrosion has been addressed by Zolin 1Z/ and
Kays !§'. The use of dual shaft mixers with slow scraper blades wiping the walls and
the bottom of mixing tanks is common in applications involving viscous liquids I2/.
COST OF CLEANING
The cost of cleaning can be viewed as being composed of the following elements:
Direct Costs
equipment assembly/disassembly
cleaning chemicals and supplies
waste treatment and disposal
cleaning labor and supervision
cleaning equipment depreciation
utility costs
Indirect Costs
planning and scheduling
cost of lost production
cost of lost raw materials inventory
inspection and testing
process equipment deterioration
Often equipment cleaning is performed by outside contractors with specialized
equipment who assume the responsibility for hauling away the waste and for disposing
of it properly.
Costs of cleaning vary widely depending upon the medium, method and application.
Recent inquiries into the cost of cleaning of heat exchangers established the following
compilation of relative heat exchanger cleaning costs using contracted service:
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Method Relative Cost
Hydroblasting 1.0
Rodding 4 to 5
Chemical Cleaning:
Without waste disposal 0.3 to 3
With waste disposal 2.1 to 4
In many cases the cost of cleaning (taken as direct cost only) is lumped together with
other maintenance costs. As a result, plant management may not have good visibility
of the actual costs of cleaning, which may impede management's support for waste
minimization efforts. Often, when plant management learns of the true cost
dimension, action to lower cleaning costs is quickly initiated.
SUMMARY
As mentioned in the introduction, the intent of this paper is to provide a brief review
of techniques, approaches and strategies for minimizing equipment cleaning waste and
to provide a classification scheme that may serve as an initial guide to those
interested in waste minimization. Such a classification or summary is provided in
Table 3. This serves as a prototype checklist for addressing all waste minimization
issues in a logical sequence.
The subject of equipment cleaning is quite diverse as the function is performed in
virtually every industry. Generalizations presented in this paper must be translated
into site-specific and exacting requirements in any waste minimization effort.
ACKNOWLEDGEMENTS
The authors wish to express their gratitude to the U.S. Environmental Protection
Agency, Office of Solid Waste, for their support in developing a substantial portion of
the material presented in this paper.
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TABLE 3. WASTE MINIMIZATION OF EQUIPMENT
CLEANING WASTE - SUMMARY OF APPROACHES
WHY IS DEPOSIT PRESENT? |
REDUCE CLEANING FREQUENCY
1. Inhibition of fouling rate
smooth heat transfer surfaces
lower film temperature/higher turbulence
control of fouling precursors
choice of heat exchanger type
2. Maximize process equipment dedication
conversion from batch to continuous operation
dedication to single composition
3. Proper production scheduling
4. Avoidance of unnecessary cleaning
REDUCE QUANTITY AND TOXICITY OF WASTE
1. Minimize amount of cleaning solution
high pressure nozzles
flow-over technique
on-stream cleaning
use of CIP systems with staged or counter-current
rinsing
reuse of cleaning solution
2. Minimize toxicity of spent cleaning solutions
clingage reduction
mechanical (hydroblasting) over chemical cleaning
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REFERENCES
1. League of Women Voters of Massachusetts, Waste Reduction; The Untold Story,
Conference held June 19-21, 1985 at National Academy of Sciences Conference
Center, Woods Hole, Massachusetts.
2. Uddeholrn Corporation (Sweden), Technical brochure on Tubec Tubes and
communications with Avesta Stainless Inc., Totowa, New Jersey
3. Knudsen, J.G., Fouling of Heat Exchangers; Are We Solving the Problem?,
Chem. Eng. Progress, Feb. 1984, pp. 63-69.
4. Jacobs Engineering Group Inc., Alternatives for Hazardous Waste Management
Practices in the Petroleum Refining Industry, EPA-530-SW-172C, Washington,
D.C., U.S. Environmental Protection Agency, 1979.
5. Colleta, V., Powers, J., Chem Proc. 44(4):20-1, 1981.
6. Cameron, J.B., Lundeen, A.J., McCulley, Jr. J.H., Hydroc. Proc., 59(3):39-50,
1980.
7. Euleco S.P.A., Euleco Continuous Process: Technical Bulletin, 1975.
8. Shell International Research Inc., Brit. Patent No. 136, 189; issued Dec. 11, 1968.
9. Peters, M.E., Timmerhaus, K.D., Plant Design & Economics for Chemical
Engineers, 3rd Edition, McGraw Hill Book Co., 1980.
10. Loucks, C.M., Boosting Capacities with Chemicals, Chem. Eng. (deskbook issue),
80(5):79-84, 1973.
11. Water Services of America, Inc., Superscrubber Technical Bulletin, 1985.
12. U.S. Environmental Protection Agency, Office of Water & Waste Management;
Development Document for Proposed Effluent Guidelines, New Source Per-
formance Standards and Pretreatment Standards for the Paint Formulating,
Paint Source Category. EPA-440-1-79-0496, Washington, D.C., 1979.
13. Hyde, J.M., New Development in CIP Practices, Chem. Eng. Progress
81(1):39-41, 1985.
14. Huisingh, D., et. al., Proven Profit from Pollution Prevention, The Institute for
Local Self-Reliance, Washington, O.C., 1985.
15. Riley, J.E., Development Document for Effluent Limitation Guidelines, New
Source Performance Standards for the Tire and Synthetic Segment of the Rubber
Processing Industry, Point Source Category, EPA-440-1-74-013A, U.S. Environ-
mental Protection Agency, 1974.
16. Barnett, J.W., Better Ways to Clean Crude Storage Tanks and Desalters, Hydroc.
Proc. 60(l):82-86, 1980.
17. Zolin, B.I., Chem. Proc. 47(9):63-5, 1984.
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REFERENCES (Continued)
18. Kays, W.B., Construction of Lining for Reservoirs, Tanks & Pollution Control
Facilities. Wiley, New York, 1979.
19. Myers Mixing Company: private communication, 1985.
20. Betz Laboratories Inc., Handbook of Industrial Water Conditioning, 8th Ed.,
Trevose, Pennsylvania 1980.
21. Paschke, L.F., Condensing Heat Exchangers Save Heat, Chem. Eng. Progress, pp.
70-74, July 1984.
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Parts Cleaning
Ed Rodzewich
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SOURCE REDUCTION - PARTS CLEANING
Edward A. Rodzewich
Introduction
The ultimate goal for any metal finishing operation is to
produce a quality product which meets or exceeds the standards of
the industry. Parts which are to be painted must be cleaned very
thoroughly and undergo a processing sequence to prepare the
surface for painting. Phosphating is the usual method for
producing a conversion coating on steel and galvanized surfaces.
Chromating is used for aluminum.
As part of an integral process operation, the cleaning step
or sequence is the most important because all of the other
processing steps are dependent on the quality of cleaning. Even
the use of the most modern state of the art conversion coating or
the best paint system will result in a lower than desired level
of quality, if the cleanliness of the surface is inadequate.
For some time now, solvents have been widely used to clean
surfaces, either by themselves or in combination with alkaline or
acidic builders and surfactants. The most commonly used solvents
for parts cleaning are the aromatic or aliphatic hydrocarbons,
ketones, esters, butyl cellosolve or carbitol and various
halogenated solvents as methylene chloride or perchloroethylene.
However, with the increased number of regulations governing
solvent emissions and air quality, the chemical suppliers who
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provide cleaning compounds are shifting away from the use of
solvents completely or are formulating products with reduced
solvent levels.
Parts being designed by engineers today make use of a wide
variety of metals, plastic and rubber components. In some cases,
solvents can soften plastic or cause swelling of rubber resulting
in a reduced application effectiveness. Where it is not possible
to clean the part without using solvent, changes in the manufac-
turing procedure may be recommended to localize the use of
solvent to one specific area where good solvent control tech-
niques can be used.
The automotive, industry is so wide and diverse that its
needs are representative of all industries, in one way or anoth-
er. Thousands of parts from hundreds of jobshops and subcontrac-
tors produce according to their specifications. As a result of
their huge buying power, they are able to exert considerable
influence on their suppliers to use safe and effective chemicals
which are environmentally safe. Their use of the task force
including all of their suppliers has resulted in many new prod-
ucts, particularly in the area of solvent reduction.
Since this industry makes use of a wide variety of cleaning
techniques, it will be highlighted. It is to be understood that,
with minor modifications at best, the products and applications
they use to control and manage solvent usage is applicable to all
industries.
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Cleaning Concept
It is a well established fact that parts cleaning is one of
the largest operations that use solvents. Is it really necessary
to continue to use such large quantities of solvent or is it
merely a convenience? What is trying to be accomplished? There
are degrees of cleanliness required and the degree of cleaning
needed is dependent on the need at the time.
The most comprehensive definition of a clean surface is one
which is free of all physical and chemical contamination, is
compatible with subsequent treatments and results in. a quality
product. The subsequent treatments may include simple inspection
for maintenance and repair, application of conversion coatings
and paint or electroplating of metals such as zinc or chromium.
This is a definition of an ultraclean surface condition.
In many cases, an ultraclean surface may not be desirable
and may lead to unwanted problems such as in-plant rusting during
storage or fabrication. A single part may be cleaned two or
three times in the course of the assembly process primarily for
inspection and maintenance purposes. This type of cleaning is
called in-process cleaning and this will be examined next.
In-Process Cleaning
The starting point for many parts is a coil of metal such as
cold rolled steel, hot dip galvanized, electrogalvanized steel
and aluminum. The parts are stamped or formed in a central
stamping plant and are subsequently packed in large bins and
shipped by rail or truck to the assembly plants. Typical parts
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include frames, leaf springs, hoods, fenders, grills, bumpers,
hinges, etc.
In the plant, the automobile is assembled in steps. During
this phase many oils and greases are applied to the parts, they
are sanded, spot welded and in general there is a lot of han-
dling. Several times during this assembly operation, the partly
assembled unit must be cleaned to remove the large quantity of
soil adhering in order to perform a quality inspection.
Cleaning is accomplished using one or two stage spray
washers. Until only recently, the most commonly used cleaning
compositions consisted of petroleum fractions and emulsifiers
mixed with water. These cleaning compositions were capable of
removing only 90-95% of the soils and left the surface with a
thin film of solvent that was capable of providing some degree of
temporary rust inhibiting properties. The cleaning baths were
prepared by adding between 10 and 20% by volume of the petroleum
fraction concentrate. Cleaning baths were drained and recharged
frequently, on the average of once a week, depending on the soil
loading.
Despite the existence of exhaust fans located at the en-
trance and exit ends of the spray washer, solvent fumes were
present in the immediate where the personnel were working. The
concentration of solvent odor was enhanced by solvent evaporation
from the film remaining on the units exiting the washer. Skin
contact with the solvent film was inevitable as the assembly and
sanding operations continued.
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Oleum Deck
After the unit has been assembled, it is conveyed to the
phosphating stage for final cleaning, phosphating and painting.
As the unit enters this area, it passes through the oleum deck
where it is sprayed completely by means of a horseshoe harness
using V-jet or fan type nozzles. Usually, four to six people.
equipped with soft brushes and/or hand pads routinely scrub all
of the surfaces they can reach. Sometimes they reach inside the
units.
The cleaning compounds used for this application are similar
to those used for in-process cleaning. However, since the degree
of cleaning required for phosphating is considerably higher, the
cleaner concentration is also used at a higher level, probably
closer to 20% by volume. Buckets are available for hand cleaning
of heavily soiled areas and contain the solvent at a 1:1
concentration. The odor, at times, was intense and cases of eye
and skin irritation was frequent despite the use of protective
gloves, clothing and solvent masks.
RESOLUTION
The in-process and oleum deck were among the very first
solvent problem areas to be addressed. As the industry moved
from predominantly steel surface to a predominantly
electrogalvanized surface, new problems associated with cleaning
these surfaces became apparent and which were not present with
solvent cleaning. Electrogalvanized surfaces are more active
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than steel. The initial alkaline cleaners were capable of
forming white stains which were readily seen through the phos-
phate coating and subsequent painting. The appearance of the
paint film resembled a mapping texture and required sanding after
the prime, to correct. At times, the alkaline cleaners formed a
pinpoint white spot, slightly raised from the surface. These
areas increased in size during phosphate and were responsible for
some cratering and protrusions through the paint film. This also
required sanding to correct before top coat application. These
stains were surface analyzed using SEM and EDAX techniques and
found to be comprised of zinc oxides.
Eventually, it was found that a relatively neutral to mildly
alkaline cleaner operating in the pH range between 7.5 and 9.5
could provide the desired degree of cleaning for these applica-
tions. Oftentimes, a slight amount of water soluble inhibitors
find use. They do nothing to aid in the removal of the soil but
they are capable of eliminating the staining problem and impart
some temporary in-plant rust protection. Neutral cleaners are
now widely used, displacing the solvent based cleaners. They
have been proven to be safe to handle by line personnel, they are
solvent free and therefore are free of odor, they are easily
waste treated and they required no equipment or manufacturing
changes. Solvent reduction for these applications as a direct
result of the use of neutral type cleaners are in the order of
thousands of gallons of pure solvent per year, per plant.
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Cleaners Before Phosphating
The degree of cleaning effected by in-process cleaning does
not reach the levels which is required for phosphating. There-
fore, subsequent to the in-process and oleum deck cleaning, the
parts must be processed through either one or two additional
cleaning steps. The requirements of a clean surface which is
needed for phosphating are: water break free surface after
cleaning, a surface free of oxide and oil polymerization stains
and a low surface carbon content. The surface carbon is a
measure of organic carbonaceous soils such as lubricants, rolling
oils and inorganic carbon. It does not measure alloyed carbon.
The measurement of the surface carbon is a laboratory procedure
based on coulometric measurements involving pyrolytic oxidation
techniques. The surface carbon content must be below 0.4 milli-
grams per square foot if a high quality phosphate coating is to
be achieved. Higher values of surface carbon can lead to phos-
phate coatings that posses marginal adhesion and corrosion
protection.
Excellent cleaning, which meets all of the requirements for
phosphating, is achieved using hot cleaners operating at about
150-160°F. The cleaning sequence could be spray, spray-dip or
immersion. In recent years, a considerable need developed for
low temperature cleaners because of the high cost of energy.
Initially, low temperature cleaning was made possible by
solvent additions to conventional cleaners. The results achieved
were satisfactory. Solvents such as kerosene, mineral spirits or
butyl cellosolve were found suitable. Cleaning temperatures were
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reduced from 150°F to 100-110°F with no sacrifice in quality.
However, solvent usage necessitated better control of the rinse
stages to prevent solvent carry over. Knock-off risers at the
exit of the cleaning and rinse stages helped to control solvent
carry-over. These emulsion type cleaners are in use today but in
view of the EPA and OSHA interests in minimizing solvent emis-
sions, their use is destined to be short lived.
The average solvent content in these cleaners vary between 5
and 10% by weight of the concentrate. For a 10,000 gallon
cleaner tank operating at a nominal 3 oz/gallon, the solvent
content is at least 187 pounds. Cleaners are dumped frequently
and recharged every two to three weeks. Over a period of one
year, this amounts to over 3000 Ibs. of solvent per cleaning tank
that must be waste treated. This value is minimal because the
calculations did not include the normal replenishment of cleaner
which takes place to maintain cleaner efficiency.
In the automotive industry, the newer generation phosphating
machines are being constructed with tanks in the 90,000 to
100,000 gallon range. The use of solvent or emulsion cleaning in
these large tanks would truly magnify the problem farther.
Most, if not all, of these solvent containing cleaners in
the automotive industry have been replaced or will be replaced by
low temperature solvent free cleaners. This direction is taking
place primarily due to the strong influence of local and state
regulations governing solvent emissions and very conscientious
monitoring by the officials.
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The development of efficient low temperature cleaners was
performed in concert with the steel companies, lubricant suppli-
ers and the R&D staff of the automotive companies. Lubricants
and rolling oils were modified or changed completely to make them
more receptive to cleaning. Steel mills modified their practice
and control in making the metal coils to reduce surface carbon
contamination, and the chemical suppliers modified the cleaning
composition. The R&D staff monitored and evaluated the activi-
ties of the suppliers and modified cleaning equipment where
necessary.
In general, the low temperature cleaners are more alkaline
and equally aggressive where compared to hot cleaners. They
differ in the type and variety of surfactants and emulsifiers to
provide low to no foaming characteristics. Soil retention in the
cleaner bath was found to be better, soil redeposition character-
istics were improved primarily because of the lower cleaning
temperatures and the variety of surfactants employed.
Short high pressure (1000 psig) cleaning zones were in-
stalled, in some instances, between the oleum deck and the first
cleaner stage. The high pressure was capable of physically
removing very tenacious soils such as carbon and loose sealants
not removed earlier.
Thermal oil separators have been installed in conjunction
with the first cleaning stage. This works on the principle of
heat. Periodically the oil laden cleaner bath is transferred to
a large tank equipped with a heater. As the cleaner bath is
heated, the oil separates and floats to the top where it is
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collected in a suitable vessel. The oil free cleaner bath is
then piped back to the cleaner stage. This technique increases
the bath life of the cleaner and decreases the frequency of dump.
This procedure is not successful for solvent based cleaners
because the solvent would be effectively removed with the oils
and cause the cleaning efficiency to fall off.
Ultrafiltration has also been attempted to accomplish the
same purpose as thermal oil separators but they have not been
readily accepted by industry due to high cost and high mainte-
nance, in comparison.
Low temperature solvent free cleaners of this type and some
of the techniques and equipment modifications are presently in
use in many spray and immersion cleaning tanks in the automotive,
coil and fabricated metal industries.
Acid Cleaning
Parts which have been stored for any period of time may
become slightly oxidized despite being treated with a protective
oil film. This condition is visible on steel parts as a light
yellow coloration or in more sever cases, red rust. Galvanized
surfaces may show evidence of white rusting. Aluminum oxidation
appears as white to black pitting. Protective oils, at times and
under favorable conditions, can oxidize and in the process react
with the metal surface to produce a hard, impervious varnish type
film. These films, oftentimes called polymerized oil spots,
resist alkaline cleaning and generally lend themselves to acid
cleaning. It is necessary to dissolve some of the metal to reach
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under the polymeric film which is then lifted from the surface.
If these oxidation products are not removed completely, poor
phosphating and paint quality will result. These oxidized areas,
if not removed will either prevent phosphating completely or will
allow an improperly formed or marginal coating to be formed.
Adhesion of phosphate coating and therefore the paint film also,
will be inferior. These sites will be prime areas for paint
chipping and corrosion.
Acid cleaning is the most effective method to remove this
surface condition. Fortunately, these conditions while serious
are generally localized in small areas and as such, should be
addressed on a case by case basis. An operator, using a brush or
a sponge soaked with the cleaner, manually wipes the area until
the contamination has been removed. A light wiping with a water
soaked sponge removes the excess cleaner and stops the cleaning
action.
Phosphoric or citric acid based cleaners have found use for
this application. In addition, surfactants and emulsifiers along
with solvents such as alcohol or butyl cellosolve are incorporat-
ed into the mixture to aid in soil removal and acid penetration.
The usage of acid cleaning, per plant, does not approach that of
alkaline cleaning. They are usually purchased in several drum
lots and placed in the various areas where inspection and repair
work is performed. This type of cleaner is found in all automo-
tive plants, job shops everywhere and even sold over the counter
in automotive retail shops and paint stores. Thus, they are a
source of solvent emission. Solvent content varies but averages
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about 10% by weight of the concentrate. A single 650 Ib. net
drum would contain 65 Ibs. of solvent. Most of these products
are found being used in areas having only general ventilation
which is very questionable and could be harmful.
The citric acid based formulations are superior to the
phosphoric acid products because they do not passivate the
cleaned area and any residue remaining on the surface after
cleaning is easily removed in the alkaline cleaner stage.
Phosphoric acid products can react with the metal to form a thin
phosphate conversion coating that will interfere with subsequent
steps. On the other hand, if subsequent phosphating will not be
performed, this thin film does provide a base for paint bonding,
but not of a high quality.
These products have been reformulated without solvent. In
the place of the solvent, a mixture of high HLB (hydrophilic,
lipophilic balance) surfactants are used. Surfactants having HLB
values around 3 readily solubilizes the oily deposits on the
surface and allows quick and effective action of the acid on the
oxidation sites. High HLB surfactants (10 or greater) allow
rapid soil emulsification and makes it easier to rinse the
reaction products of the cleaning action and excess unused acid.
Acid cleaning of this nature, while being of a magnitude of
use lower than alkaline cleaning, does have a place in industry.
Vapor Decreasing
Vapor degreasing units basically are devices for heating a
volatile solvent. By providing a simple cooling jacket above the
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liquid solvent, the zone between the liquid and the cooling
jacket becomes enriched with solvent vapor. The freeboard area
above the water cooling jacket is equipped with condensing coils
to help control any solvent emission into the workplace. Clean-
ing takes place by the hot vapors condensing on the part. This
vapor condensation continues until the part reaches the tempera-
ture of the vapor. The commonly used solvents are 1,1,1
trichloroethane, trichloroethylene, perchloroethylene and
methylene chloride. Vapor degreasing is used for cleaning many
surfaces including glass, plastics, combinations of metals and
plastics provided the solvent does not react with any of these
surfaces. It is a very effective cleaning method but it is not
capable of producing a chemically clean surface. It has some
limitations. It is not an effective method for removing heavily
pigmented soils, oftentimes leaving residues of the pigment which
resist subsequent removal. Thin sections of metal heat almost
instantly to the vapor temperature of the solvent and little to
no soil is removed. To produce a truly clean surface to the
degree required by phosphating or plating, a subsequent alkaline
cleaning or acid cleaning step is required.
Vapor degreasing units have been replaced or not installed
in certain applications and in their place alkaline cleaners have
found increasing use. Alkaline cleaning is finding favor because
they have proven to be more effective than vapor degreasing, for
the application, easier to use and control, more economical to
handle and pose no environmental problems.
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Typical examples where this has occurred is in the manufac-
ture of aluminum computer discs and production items such as
television tube grids or radio panels which contain a screen like
series of minute holes across the surface.
The computer discs are highly polished and mirror like in
appearance. It is important to retain this appearance throughout
the manufacturing sequence. This is a highly technical applica-
tion where cleanliness reigns supreme. Immersion alkaline
cleaners based on builders such as complex phosphates, biodegrad-
able free rinsing and water soluble surfactants together with
specially formulated silicates to prevent any possible metal
attack are being used for this purpose. Such cleaners are very
safe to use from a personnel viewpoint and required minimal
control to continue remaining effective.
Cleaning of television shadow masks or other similar shapes
which contain a series of tiny holes was always considered an
ideal item for vapor degreasing. It was considered to be the
only way, cleaning could be accomplished inside the holes.
However, it was determined that spray alkaline cleaning was
superior method for this application. Highly sequestered clean-
ers free from silicates or soda ash which have a tendency to
precipitate hard water salts and very low surface tension produc-
ing surfactants are required. After cleaning, the part is rinsed
with a final de-ionized water rinse and dried in a low heat
convection oven.
This approach leaves the surface chemically clean, free of
cleaner residue and free of thin oily films commonly found after
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vapor degreasing. Surfaces thus produced are suitable for
phosphating, plating or other applications.
Wherever parts are cleaned and painted, there are needs for
products related to producing a quality job and which are suit-
able for any discussion concerning solvents. Paint stripping and
paint booth coatings merit an examination.
Paint Strippers
In every job shop or manufacturing site where parts are
cleaned and painted, there is a need for paint strippers.
Methylene chloride is the most widely used solvent for removing
paint from steel and aluminum surfaces. There is a nationwide
research goal to find a viable substitute for methylene chloride
as a paint stripping agent, but to date, none has been found
despite many claims being made to that end. Methylene chloride,
by itself, is not too effective as a paint stripper. It needs
the help of various acidic activators, such as formic or acetic
acid, to be truly effective. Formic acid is far and away the
most effective activator available. Inhibitors are added to the
mixture in order to protect the metal surfaces against acid
attack during the stripping process and to prevent the stripped
bare surface from flash rusting while the parts are drying.
Stripping tanks vary in size from several gallons to several
hundred gallons. The methylene chloride content averages 90-95%.
Because of its low boiling point of 105°F, the tanks generally
are fitted with lids that can be mechanically raised or lowered
during use, to prevent evaporation losses. This technique to
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reduce evaporation losses is helpful but not truly effective. At
times water seals are employed but these are seriously lacking in
their capability to prevent evaporation losses and in addition,
its use serves to decrease the life expectancy of the stripper
bath. The organic acid activators preferentially migrate from
the solvent layer to the water layer, where they are more solu-
ble. As the migration progresses, the stripping efficiency falls
off until its is no longer effective for the purpose intended.
Seals are available commercially that have proven to be very
effective. These seals consist of highly polar components which
are insoluble in methylene chloride but are soluble in water.
These seals, being lighter than methylene chloride, float on the
surface. As the stripped part is being removed from the tank, it
passes through the seal layer where the seal layer displaces the
methylene chloride solvent leaving thin film of a water soluble
components. By incorporating a rust inhibitor in the seal layer,
flash rusting during drying is eliminated. Evaporation losses,
using these seal layers can be as high as 40%. There is little
to no tendency for the activators to migrate into the layer
because they are more soluble in the methylene chloride. As are
result, paint stripping efficiency remains constant for the life
of the bath.
Products have recently become available where the methylene
chloride content has been reduced by 60%. Techniques have been
found to produce a stable solutio of methylene chloride in an
aqueous medium. In effect, the methylene chloride molecule
becomes surrounded by water molecules resulting in an in-situ
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type water seal. This approach is certainly novel and it is
tremendously effective in reducing evaporation losses. It has
been found that the activity of the acid activators and inhibi-
tors commonly employed are enhanced in such a medium. This
technique effectively minimizes evaporation losses and because of
the lower usage of methylene chloride, it is a viable method for
source reduction of a powerful paint stripping solvent.
Booth Coating Compounds
Booth coating compounds are removable temporary barrier
coatings which are applied to spray booth walls, gratings and
floors to facilitate entrapment and disposal of accumulated
overspray paint. In addition they serve to provide an excellent
light reflecting surface which is very beneficial in application
of paint and results in a minimal amount of rejects. The white
dry flexible barrier coatings are considered the best type to use
because they afford the best light reflection. As the paint
overspray accumulates, the barrier coating is simply peeled from
the surface, discarded and a new barrier coating is applied
either by brushing or by means of a paint spray gun. The entire
sequence of peeling the coating from the walls of the paint booth
and the application of a new film takes about one hour, depending
on the size of the booth. Half of that time is used to allow the
coating to dry before use.
A typical white booth coating compound consists of an
acrylic co-polymer resin dissolved in a mixture of methylene
chloride, xylene and toluene and pigmented with titanium dioxide
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to form a stable emulsion. Small amounts of plasticizer is used
to keep the dry film flexible and pliable. Approximately 50% by
weight of these compositions consist of solvent which escapes
during drying. One gallon usually is capable of covering about
600 square feet of area at 1-3 mils thickness. Each gallon
contains about 6-7 Ibs. of solvent. Very good local ventilation
is required during the application process and spray equipment
which contains any aluminum or galvanized steel parts must be
avoided because of the danger of hydrogen gas forming. Stainless
steel spray equipment is an absolute requirement. There have
been instances reported of temporary asphyxiation resulting
because of inadequate or inoperative ventilation. Fortunately,
this was a temporary condition and the personnel recovered
completely after being removed to fresh air.
Recently high solid formulations have been developed and
sold commercially. About 85% by weight represents the total
solids content as a waterborne copolymer emulsion and titanium
dioxide pigment. The remainder being water and a small amount of
a cellosolve type solvent. Average VOC content of commercially
available booth coating compounds of this type is 0.2-0.3 Ibs per
gallon.
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These products perform equally to the solvent based products
but they posses several advantages over the solvent based materi-
als.
1. non-flammable
2. 10-20% greater coverage
3. no restriction as to construction of
spray guns
The high solids water based booth coating compounds are
rapidly replacing the solvent based products and they are consid-
erably safer to apply. These products are used wherever parts
are painted.
Summary
This short review attempts to highlight the use of solvents
in parts cleaning and to enumerate the alternatives to solvent
cleaning of parts on a case by case perspective.
Certain areas such as paint strippers and temporary barrier
booth coating compounds which are indirectly related to parts
cleaning use a considerable amount of solvent. While it has not
been possible to eliminate solvent usage in these products,
significant advances have been made to significantly reduce their
effective solvent content.
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Session III
Reuse and Recycle
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On-site Reuse and Recycle of
Halogenated Waste Solvents
E. Richard Randolph
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CONTENTS PAGE
Introduction 3
Waste Reduction: Background 3
Trends in Chlorinated Solvents Use 5
Recycling Through Contract Reclamation 7
Recycling Through In-House Reclamation 8
Waste Reduction: Customer Assistance 12
Factors Influencing Solvent Consumption 13
Waste Disposal Issues 18
Conclusion: The Benefits of Waste Reduction 18
Appendix A 19
Appendix B 20
Appendix C 21
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INTRODUCTION
Numerous examples have shown that waste-reduction programs
result in a cleaner environment, less worker exposure to
chemicals, and significant savings in fuel, feedstock, and
environmental-control costs.
The Dow Chemical Company has practiced waste reduction
and shared its expertise with customers for more than two
decades.
In order to illustrate some principles of waste management,
this paper will describe internal and external efforts to reduce
waste from the use of specialty chlorinated solvents including
a description of in-house recycling factors influencing
solvent consumption, and issues in solvent waste disposal.
WASTE REDUCTION; BACKGROUND
Dow has practiced waste reduction since the 1960s, when
Chief Executive Officer Carl Gerstacker developed a pollution-
control plan that called for employee involvement and rewards for
achievement. He sought to improve yields, reduce waste, and find
ways to use waste.
Significant dates in the regulatory and legislative history
of waste reduction include: 1976, when the Environmental
Protection Agency listed waste reduction at the top of a
preferred hierarchy for waste management; and 1984, when Congress
defined the desirability of waste reduction as a national policy.
In 1987, Dow grouped the internal efforts that grew from
Gerstacker's plan under a program called WRAP Waste Reduction
Always Pays. (The service provided to chlorinated solvents users
is called the Waste Reduction Assistance Program. Details begin
on Page 12).
The importance of a plan such as WRAP is that it is long-
term, and formalizes past, present, and future waste-reduction
efforts in order to track progress and chart a course (see Fig.
1). Goals are to:
o Reduce waste in all media.
o Create a disposition toward waste reduction.
o Provide incentives to reduce waste.
o Recognize excellence in waste-reduction efforts.
o Save money (including avoided costs).
o Lessen future liability.
Waste reduction can be defined as:
o Any in-plant practice or process that avoids,
eliminates or reduces waste so as to reduce
environmental risk to any media.
o The treatment, reuse or recycling of any material
that reduces the volume and/or toxicity of waste
prior to final disposition.
The Louisiana Operations Division a large, diversified
manufacturing division provides excellent examples of success
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Fig. 1
WRAP Flow Chart
Develop Historical Benchmark For Each Process
Inventory All Losses To Air, Water, Land
(Quantity t Quality)
Identify Source Of Losses
Prioritize (Volume And Screening Method)
Set Goals
Determine Cost Effective Actions
Allocate Resources
Implement Actions
Document & Report Progress Routinely
Communicate Internal fi External
Plan For Future Reduction
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in waste reduction. In the past decade, hydrocarbon emissions
dropped 92% and chlorinated hydrocarbon discharges to water
dropped 98% while production increased from about 8 billion
pounds per year to 12 billion pounds per year.
The division utilized techniques such as improving the
purity of raw materials, improving instrumentation, using on-
stream analyzers, using process analysis by statistical methods,
and improving maintenance.
TRENDS IN CHLORINATED SOLVENTS DSE
Specialty chlorinated solvents include 1,1,1-
trichloroethane, trichloroethylene, methylene chloride, and
perchloroethylene. The diverse applications for these products
include metal cleaning (by means of cold cleaning and vapor
degreasing), dry cleaning, chemical processing, and production of
fluorocarbons, aerosols, paint removers, adhe^ives,
coatings/inks, and blowing agents.
The demand for metal-cleaning solvents far outweighs the
demand for chlorinated solvents for any other application (see
Fig. 2). It is more than twice the demand for dry cleaning
solvents and three times the demand for fluorocarbons production
solvents. Dry cleaning and fluorocarbons production are the
second and third largest applications for chlorinated solvents,
respectively.
Metal-cleaning solvents represented 38.2% of the total
demand for chlorinated solvents in 1984 and 34.6% of the total in
1987. Although demand for metal-cleaning solvents dropped 139
million pounds in those three years a decline disproportionate
to the 194-million-pound drop in total demand metal cleaning
still is the most significant application for these four
chlorinated solvents in the United States.
Conservation and efforts to encourage more efficient use
of solvents have contributed to both the decline in demand for
all virgin chlorinated solvents and the decline in use of virgin
chlorinated solvents for metal-cleaning applications.
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Fig. 2
Applications/End Uses
For Specialty Chlorinated Solvents
BUU
700
600
500
400
300
100
-
754
0 "H
4^ C
H
O
344
208 186 M»
142 137
O\ OJ OJ O* OB (4
c c ' fi -u M o
45 oc o «J-H CT co x:
SJ3 O 03 O OJ -U -«H > 4!
M
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RECYCLING THROUGH CONTRACT RECLAMATION
Many chlorinated solvents users hire companies with the
technology to reclaim solvents from waste sludges. The following
table illustrates the growth of contract reclamation.
CONTRACT RECLAMATION INCREASING
Year Pounds reclaimed % of all solvents
(in millions) users buying
reclaimed solvents
1977 69 20-25
1982 147
1986 268 75-80
1990 310 (estimate)
When recycled solvents enter the marketplace, the demand for
virgin solvents drops correspondingly. And, reclaimed solvents
come primarily from metal-cleaning applications.
The quality of recovered solvents may vary for reasons
including stabilizer depletion and cross-contamination with other
solvents or compounds.
Problems that can occur because of improperly stabilized
solvent include:
o Dilution of fresh solvent, which can shorten
solvent life.
o Reduced acid acceptor content. This can decrease
the margin of safety before an acid condition
develops in cases of stress.
o Reduced metal stabilizer content, which decreases
or eliminates protection from corrosion. Corrosion
produces acid that degrades solvent and consumes
acid acceptor.
o Excess stabilizer content, a potential
flammability hazard.
o Improper stabilizer ratio, which reduces the
effectiveness of metal stabilizers.
o Contaminated solvent. Such contaminants as
aromatics in methylene chloride and 1,1,1-
trichloroethane in trichloroethylene can cause
reactions that result in an acid condition,
especially in the presence of aluminum.
o Excess water. This shortens solvent life, causes
greater vapor loss, and creates corrosion and/or
spotting on the work.
As Fig. 3 shows, the demand for virgin chlorinated solvents
was sluggish between 1971 and 1980, and has fallen since 1980.
That decline corresponds almost directly to the increase in total
pounds of reclaimed solvents on the market since 1980.
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Fig. 3
U.S. Demand For Chlorinated Solvents
2500
2000
1500
CQ
2
1000
500
Total Virgin
Virgin MC
........ Reclaim
I
1971 1974
1977
1980
1984 1987
1990
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RECYCLING THROUGH IN-HOOSE RECLAMATION
While the contract reclamation industry was growing,
chlorinated solvents users also were finding ways to recover
solvents in-house. In 1983, 52% of the customers that Dow knew
were using chlorinated solvents, were recovering in-house. That
figure was up to 64% in 1987.
The use of in-house stills to recover solvent and
concentrate waste typically results in up to a 20% reduction in
solvent use. In-house solvent recovery is tantamount to source
reduction because it eliminates a need for virgin material.
Distillation recovery equipment falls into three categories:
process stills, in-house solvent recovery equipment including
units that are the same type of equipment as process stills, and
semiportable ministills and thin-film evaporators. In
addition, the vapor degreaser can be used as a quasi-still by
means of the boil-down procedure (see Appendix A).
Process stills are used in conjunction with vapor
degreasers. Dirty solvent from the sump of the degreaser is
pumped to the still for distillation, then returned to the
degreaser's offset clean solvent storage tank.
A degreaser with a still does not have to be shut down and
cleaned to remove contaminants as often as a degreaser without a
still. Periodically, the still is opened and the sludge removed
while the degreaser continues operating. This process is called
continuous distillation and can produce a waste that is
approximately 25-50 percent solvent.
Process stills are often steam-heated, but can also be
electrically heated or steam-fired. Their recovery rates are
expressed in gallons per hour, and typically run from 30-200 gph.
About 62% of Dow's larger customers recovering solvents on-
site use process stills.
In-house solvent recovery equipment offers a specialty
technique for minimizing solvent waste and eliminating the need
to send spent solvent to an outside reclaimer.
To recover solvent, spent solvent is collected and stored
until enough accumulates to fill a still. The contaminated
solvent is pumped into the still, distilled, and recovered in
drums or storage tanks. This is called batch distillation and
removes 70-95% of the solvent in the waste.
Larger units are the same type of equipment as process
stills, except that they are not necessarily used in conjunction
with vapor degreasers.
Some newer, small-capacity units are electrically heated and
recover solvent over a long period, typically about eight hours.
Based on hundreds of calls on customers over the past four years,
Dow estimates only about 1-2% of customers recovering solvents
on-site use these ministills.
Thin-film evaporators are used for high-volume solvent
recovery. Their application is primarily for continuous feed, and
capacities range from 50-500 gph. Solvent recovery is 90-95%.
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Recovered solvent fits into one of these three categories:
o Clean solvent.
o Clean solvent with the measured addition of acid
acceptor.
o Clean solvent, analyzed for inhibitor content and
restabilized with both acid acceptor and metal
stabilizers as required.
The latter two categories usually are obtainable only
through contract reclaimers.
The recovered solvents that are obtained from in-house
distillation usually can be used directly in the cold cleaning or
vapor degreasing process as a replacement for some virgin
solvents. However, because the quality of recycled solvent can
vary, it should be monitored by analysis and used only as a blend
with virgin solvent.
Fortunately, in-house distillation is not often subject to
cross-contamination, and blending with virgin solvents during
reuse should keep stabilizers within satisfactory limits.
In some cases, however, it is necessary to restabilize
recycled solvents in-house when inhibitor depletion is excessive
and unavoidable. An example would be to add acid acceptor to
trichloroethylene that has been depleted by carbon adsorption
recovery. Some, not all, stabilizers are provided commercially in
a safe and effective manner.
Depending on the equipment utilized and the nature of the
production process, waste solvents and residues from in-house
distillation are sent out for further reclamation or disposal
(see Fig.4). As a broad rule of thumb, solvent wastes containing
up to 30% oil are forwarded to contract reclaimers. Solvent
wastes containing 30-90% oil are sent to fuel blenders through a
waste broker. Wastes with more than 90% oil are sent directly to
disposal via thermal destruction. (A discussion of waste disposal
issues starts on Page 18).
Some chlorinated solvents users enhance solvent recovery
with steam sparging, stripping, or specialized collection systems
such as double distillation. Such techniques, practiced on large
quantities of waste, allow chlorinated solvents users to reduce
their waste production substantially and fall more in the realm
of waste management than waste reduction.
The major incentive to practice solvent reclamation is to
save money. For the same reason, solvents users are insisting on
tighter machines, wasting less solvent, and looking for even more
ways to use solvent more efficiently.
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Fig. 4
Flow Diagram
Hazardous Waste Disposition
Any
Generator
(Customer)
In-House Recycling
Solvent
Sludge
Landfill
Incinerator
Fuel Blender
Reclaimer
Sludge
Permitted
Hazardous
Waste
Hauler
Clean
Solvent
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WASTE REDUCTION; CUSTOMER ASSISTANCE
In 1976, the Environmental Protection Agency hired Dow to
conduct a study to support new source performance standards for
solvent metal-cleaning operations.
Under that contract, K.S. Surprenant and D.W. Richards
identified and quantified emission control techniques being
practiced at that time. They included use of covers, liquid
absorption, carbon adsorption, use of refrigerated freeboard
chillers, refrigeration condensation, and good operating
techniques.
The study indicated that a large portion of the solvents
emitted to the atmosphere and basically wasted resulted from
inefficient cold cleaning and vapor degreasing. Since there were
many techniques to improve efficiency and reduce waste during
these operations, the study reinforced the commitment to assist
solvents users.
The effort became the Waste Reduction Assistance Program,
which has four elements: field support services, product
stewardship, training and seminars, and literature.
Field support services. In 1986, 44% of the calls made by
chlorinated solvents technical service personnel related to
waste reduction. In 1987, 53% involved waste reduction.
Waste reduction-related field support services include:
o Process troubleshooting, including visiting the
plant to identify problems, as well as handling
inquiries over the phone.
o Vapor degreaser inspections to determine if there
are problems with the design or maintenance of the
degreaser or associated equipment.
o Recommendations covering all phases of degreaser
operation, including heat balance, water handling,
and parts handling.
o Engineering consultations involving cleaning of
metal and design of equipment.
o Waste- and emission-reduction recommendations.
Product stewardship. Examples of product stewardship as it
relates to waste reduction are locating and monitoring vapor
concentrations in the workplace and suggesting ways to
reduce them. Monitoring includes taking halide meter
readings and dosimeter readings, as well as conducting
professional industrial hygiene surveys in some cases.
Training and seminars. Training is one of the most important
facets of waste reduction. Topics include product
application, maintenance, the theory of vapor cleaning,
environmental and regulatory updates, and safety. Programs
can take place in groups or one on one and are available to
distributors of chlorinated solvents, distributors'
customers, direct customers, and Dow's own field personnel.
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Literature. Waste reduction is covered in solvent Material
Safety Data Sheets, Product Stewardship Manuals, application
brochures, newsletters (see Appendix B) , and other
publications.
These four elements, practiced together, constitute a
formidable solvent-management program that is much stronger than
any one of them practiced alone.
FACTORS INFLUENCING SOLVENT CONSUMPTION
Most of the techniques for reducing waste during cold
cleaning and vapor degreasing are easy to follow and improve the
efficiency with which the operations use solvents. Every pound of
solvent conserved results in the equivalent pound of reduced
demand for virgin solvents and reduces the volume of solvents
requiring recycling or disposal.
Cold cleaning
Good operating practices are essential to curb solvent
consumption during cold cleaning and they are mostly a matter
of common sense.
To minimize evaporative losses:
o Use covers.
o Use a water layer on top of the solvent where
acceptable.
o Use a coarse spray or solid stream of solvent
instead of a fine spray.
o Control ventilation.
o Place wipe rags in a closed container and use them
again wherever possible.
o Minimize open surface area.
o Use a deep tank with a high freeboard.
o Use specially designed containers with automatic
lids and drains.
o Drain parts properly to capture as much of the
solvent as possible.
o Don't use compressed air sprays to blow dry parts
or to mix cleaning baths.
To reclaim solvent:
o Capture and distill any waste.
o Dispose of sludges at the proper time to avoid
stressing the solvent.
Vapor degreasing
Reclamation of reusable solvent from waste sludges is
important, but only about 15-30% of the solvent used for metal
cleaning by vapor degreasing becomes waste. The other 70-85% is
eventually lost to evaporation after multiple uses in the
system through inefficient operation and maintenance of the
-------
degreaser and associated equipment. Techniques to reduce overall
emissions from a degreaser and to fine tune degreaser operation
conserve some of that 70-85%.
Specific suggestions for minimizing solvent loss and
reducing the cost of using solvent during vapor degreasing fit
into seven general categories.
1. Ensure proper degreaser operation.
Leave the unit on to maintain the vapor level unless it
won't be in use for long periods of time.
Don't expose heating coils to vapor. This could result
in a breakdown of the solvent and corrosion problems in
the unit, in addition to loss of solvent.
Provide proper maintenance. Remove visible corrosion
and repair leaks. Repairing leaks alone can result in
up to a 50% reduction in solvent loss.
Use and maintain appropriate design and safety devices.
These devices include solvent level controls and vapor,
condenser water, and boiling sump thermostats.
2. Maintain proper heat balance.
Use the least amount of heat required to keep the
solvent at a slow boil and to give adequate vapor
production. High heat provides only rapid vapor
recovery, not improved cleaning.
Regulate the cooling level either by adjusting the
temperature of the cooling water or by altering the
flow rate of the cooling water. The vapor level should
balance at the midpoint of the condensing coils; a
fluctuating vapor level pumps the vapor-air mixture out
of the unit,
3. Minimize vapor diffusion.
Reduce exhaust velocities to provide adequate
protection of workers, yet not draw vapors out of the
degreaser. Adjusting exhaust velocities can achieve up
to a 50% reduction in solvent loss.
Cover open-top degreasers, especially during idle
times. This is the most significant solvent
conservation method; it can reduce solvent loss up to
55%. Sliding covers do not cause turbulence when moved,
unlike hinged covers.
Extend the freeboard. Units with freeboard heights that
are 40% of the width of the degreaser can use up to 40%
more solvent than units with ratios of 75-100%.
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Use cold traps an upper set of very cold coils that
cool the air above the vapors. Properly used, cold
traps provide a dense air blanket that helps prevent
vapor escape.
Cover the water separator to prevent any possible vapor
loss.
Check the water jacket for proper water flow and
temperature on the outside of the degreaser to prevent
migration of hot vapor up the side walls.
Prevent drafts over the degreaser. Fans, air condition-
ers, heaters, windows, doors, general plant air
movement, and equipment movement can blow the vapor-
air mixture out of the degreaser. Locate the degreaser
to minimize natural drafts or use baffles to prevent
upset of the vapors and achieve up to a 30% reduction
in solvent loss.
Also, vapor control with lip vent or hood exhaust
may be too forceful, so reduce exhaust velocity to the
minimum level that provides proper vapor control in the
working area.
Some semi-closed machine designs tend to channel
and reinforce air current through the machine,
especially if power-exhausted. Rearranging air movement
in the room helps to eliminate the wind-tunnel effect.
4. Minimize water contamination.
Avoid adding water. This is important to prevent
depletion of stabilizers, which results in solvent
decomposition and corrosion from acid formation by
hydrolysis. Condenser coils, cold trap coils and the
water jacket can be too cold, resulting in condensation
of atmospheric moisture. Also, wet parts can introduce
water, particularly as a component of water-soluble
cutting oils.
Dewater the solvent. A water separator should be able
to reduce dissolved water in the solvent. Also, skim
floating water off the top of the solvent, since this
represents excessive water content. Water and solvent
form an azeotrope at boiling temperatures. The
azeotrope has a lower density than dry solvent vapors
and is harder to contain.
In .all a separate water trough for refrigerated coils.
Cold trap coils can build up a heavy dew. A separate
discharge for this condensate is necessary to avoid
introducing the water to the solvent at a common water
-------
separator, which reduces the water separator's
effectiveness and perhaps would overload its capacity.
5. Establish proper workload handling.
Ensure parts are up to temperature before removal. The
cleaning cycle isn't complete until the parts have
reached the temperature of the vapor so that
condensation has ceased. If condensation is still
forming, solvent carryout will increase.
When cleaning metal parts with spray, spray below the
vapor zone. Spraying above the vapor zone generates a
vapor-air mixture directly, which is immediately lost.
Also, falling droplets of solvent disrupt vapor
interface, causing more vapor-air mixing. Spraying
below the vapor zone can achieve up to a 5% reduction
in solvent loss.
Move the work slowly. (See Appendix C for instructions
on using the stop-and-go technique). Control the hoist
speed to less than 11 feet per minute of vertical
travel and ensure the proper conveyor speed.
Don't overload the degreaser. Too large a mass of metal
creates inefficient cleaning, excessive vapor drop,
slow vapor recovery, and longer cleaning cycle,
resulting in increased solvent consumption.
Use properly sized baskets. Large baskets that fill the
area of the degreaser opening create a piston action
when entering and leaving. This forces vapor out, which
creates more solvent-vapor-air mixing. The basket
should have an area of less than 50% of the degreaser
opening.
Drain the parts. Solvent not allowed to drain properly
from parts is lost immediately to evaporation outside
the degreaser. Adjust the spacing in the baskets or the
racks so drainage can occur.
6. Avoid solvent carriers and solvent-absorbent materials.
This includes such items as ropes, spacers, and wooden
covers. Also, don't clean shop rags or gloves in the
degreaser. Up to 5% savings in solvent are possible
here.
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7. Ensure proper solvent condition.
Remove metal fines and parts, sludge, and oil buildup.
Maintain inhibitor levels. Depletion of inhibitor
levels could result in a catalytic breakdown of the
solvent to form hydrochloric acid or metal chloride
complexes, causing corrosion.
Use the boil-down procedure. (See Appendix A.)
Practice contract or in-house reclamation.
Modifications to existing degreasers
To improve the efficiency with which a degreaser uses
solvent:
o Install automatic slide covers.
o Increase freeboard height.
o Install refrigerated freeboard chillers.
o Use carbon adsorption lip exhaust.
o Attach air refrigeration on the vent recycle.
o Install programmable transporters.
Case histories
Below are two examples of how waste reduction benefited
chlorinated solvents users.
One user consumed 500,000 pounds of trichloroethylene per
year in eight large cross-rod degreasers with process stills
attached. Waste from the stills was dumped into a storage tank
about every two days, then collected in drums for disposal. Waste
amounting to about 20 drums a month was collected from each
still.
To minimize waste and reclaim more solvent, thus reducing
costs, the user now pumps the waste from each still into a
holding tank. About every two weeks, the waste is redistilled,
stirred, and steam sparged to remove as much solvent as possible.
This procedure reduces waste from 20 drums a month to five
drums a month and reduces virgin solvent consumption by 15 drums
a month.
The second user has a 3 foot-by-5 foot, open-top vapor
degreaser to clean and finish parts from other companies.
Investigation of why the degreaser was cleaning poorly turned up
two problems.
First, the cleaning basket was too large. It was acting as a
piston, pushing out vapors each time it was lowered into the
degreaser. This increased the vapor-collapse amount and shortened
the actual cleaning time.
Second, the disk-like metal parts were stacked too closely
in the basket, resulting in inadequate cleaning and solvent
entrapment.
-------
Reducing the size of the cleaning basket and stacking parts
differently allowed the user to improve cleaning and reduce
solvent virgin consumption by up to 50%.
WASTE DISPOSAL ISSUES
Even with the most efficient waste-reduction efforts, waste
disposal still is necessary. That means environmentally sound
reclaimers, proper disposal, and fuel blending/burning usually
in cement kilns or industrial furnaces are important.
Many commercial reclaimers manage their wastes as fuel. In
1981, 18% of the waste from commercial reclamation of chlorinated
solvents was managed as fuel. By 1986, the total was 49%. Some
experts would put today's figure at more than 90%. Disposing of
this type of waste through fuel blending/burning has become even
more significant as restrictions on disposal in landfills have
increased.
Burning wastes that have been blended into fuel in cement
kilns is particularly efficient. Not only are wastes used as
energy, but the chloride ions from chlorinated-solvents waste are
incorporated into the cement. Without fuel blending and
subsequent burning in cement kilns, there would be inadequate
commercial incineration capacity for the wastes that are being
generated in the United States today.
CONCLUSION; THE BENEFITS OF WASTE REDDCTION
Reducing waste from the use of chlorinated solvents for
metal cleaning means lower solvent costs and lower waste-disposal
costs. The improved efficiency that helps reduce waste also means
improved cleaning with no increase in solvent usage, another
savings.
Dow hopes assisting chlorinated solvents users with waste
reduction will attract new customers, maintain existing
customers, reduce their liability exposure, and maintain the
viability of the solvents marketplace all economic motives.
Other significant reasons for practicing waste reduction
to lower worker exposure to vapors, to reduce solvent loss to the
environment, and to comply with health and environmental laws
also have economic benefits.
And the fact that so many reasons relate to costs is
important. It gives credibility to the assertion that voluntary
waste reduction will work.
Waste-reduction efforts and long-standing environmental and
product stewardship programs demonstrate a commitment to
protecting the environment. But waste reduction is just one part
of waste management. So safe, permanent waste management and
compliance with state and federal laws still are top priorities.
Yet the bottom line really is that electing to take a
responsible approach to waste reduction makes good economic
sense. Waste Reduction Always Pays.
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APPENDIX A
Procedure for boil down of a still/degr§aser
When the temperature in the boiling sump of the still
reaches 194 F (using trichloroethylene as an example),
concentrate the sludge in the still. Turn off the transfer pump
and close the gate valve in the dirty solvent line. Continue to
distill until the liquid level reaches the recommended minimum
level of two inches above the heating element(s).
Turn off the heat in the boiling sump and allow the solvent
sludge to cool to 90 -100 F before draining. Drain the solvent
into a 55-gallon drum(s). Remove parts, metallic fines and chips,
or other insolubles by filtration or decantation. Give particular
attention to the area under the heating elements.
Close the drain valve. Open the gate valve in the solvent
line from the degrearr^r boiling sump to the still boiling sump.
Turn on the transfer >ump.
Once the liquid level reaches two inches above the heating
element(s), turn on the heat. Add the necessary virgin solvent to
the clean dip of the degreaser to properly maintain the needed
liquid levels in all chambers of the degreaser and still.
Add the sludge solvent that was placed in the drum(s) back
into the still boiling sump at the next boil down when the
solvent reaches the minimum level of two inches above the heating
coils.
After the third or fourth boil down, send a sample from the
sludge drum to a laboratory for determination of nonvolatile
content. When the oil concentration reaches 60-70%, dispose of
the sludge material in compliance with regulations governing the
disposal of waste products. Thermal destruction through fuel
blending or incineration is recommended.
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APPENDIX B
SOLVENT
Specify Dow ... For Quality Solvents, Unmatched Technical Support
Vol. 1, Number 6 June 1987
Prolong Solvent and Equipment Life
By Controlling Water Contamination
iVater in a degreaser can mean problems, employing a water separator. For water Water scj
; in contact with boiling sol- separation, the condensed solvent/water mimj
^ ^eo^uipment corro- mixture drops into a trough below the co(v>
_have a denser coils and flows by gravu>
^separator.
ater hasj
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APPENDIX C
Stop-and-go technique
The following procedure was developed to reduce solvent
concentration in the ambient air near the degreaser. It also will
reduce the solvent loss from a degreaser.
Lower the work load into the vapor zone at a slow speed.
Otherwise, an excessive wave formation of the vapors will push an
unnecessary amount of the vapors out of the degreaser.
The vapors will collapse as the work load enters the vapor
zone. Whenever the vapors have dropped two to four inches, stop
the load until the vapors stabilize or start to recover. At this
point, lower the load further until the vapors have dropped
another two to four inches.
This stop-and-go method of entry prevents solvent vapors
from being pushed out of the degreaser by the plunger effect of
the work load. It allows maximum vapor recovery with shorter
cleaning cycles.
Once the work load is covered by the vapors, it need not be
lowered further. Maximum area between the work load and the
boiling sump gives optimum vapor recovery. The work load should
never sit on top of the boiling sump.
Remove the work load in increments of two to four inches
with pauses to allow the vapors to be entrapped in the freeboard
area. This decreases vapor drag out. Once the work load has
cleared the vapor zone, it should remain in the freeboard area
until all parts are dry and no solvent drips from the work load.
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NOTICE: Dow believes the information and recommendations herein
to be accurate and reliable. However, since any assistance
furnished by Dow with reference to the proper use and disposal of
its products is provided without charge, and since use conditions
and disposal are not within its control, Dow assumes no
obligation or liability for such assistance and does not
guarantee results from use of such products or other information
herein; no warranty, express or implied, is given nor is freedom
from any patent owned by Dow or others to be inferred.
Information herein concerning laws and regulations is based on
U.S. federal laws and regulations except where specific reference
is made to those of other jurisdictions. Since use conditions and
governmental regulations may differ from one location to another
and may change with time, it is the Buyer's responsibility to
determine whether Dow's products and services are appropriate for
Buyer's use, and to assure Buyer's workplace and disposal
practices are in compliance with laws, regulations, ordinances,
and other governmental enactments applicable in the
jurisdiction(s) having authority over Buyer's operations.
-------
On-Site Reuse and Recycle of
Petroleum Waste Solvents
Robert H. Salvesen
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ABSTRACT
In-plant reuse and recycle of solvents is an accepted practice
in many industries. This paper reviews practices and equipment
which are appropriate for cleaners of parts and equipment.
Only non-halogenated solvents are discussed. The major types of
solvents utilized are hydrocarbon (such as mineral spirits and
naphthas) and oxygenated (i.e., MEK, MIBK, Ethyl Acetate and
alcohols) materials. By proper segregation, labelling and
management, essentially all solvents can be recycled.
Information is provided on the types of solvents which can be
recycled, equipment available, economic factors for
consideration and examples from industry on how recycling works.
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IN-PLANT REUSE AND RECYCLE OF SOLVENTS
INTRODUCTION
Solvents used in most industrial operations serve as cleaning
agents or reaction media. In most cases, the solvents are not
consumed but are contaminated by other substances. The solvents
are disposed when the contaminant level exceeds certain criteria
limits. These limits can vary widely depending upon the
particular process. For example, for engine parts cleaning, the
solvent may contain up to 30-40% fuels, oils, water and solids
before it needs to be replaced. In other cases, high purity is
required and contamination exceeding a few parts per million
signals a time to change solvents. Thus, while the composition
of used solvents can vary considerably, the methods for reuse
and recycling are applicable to many process operations.
This paper deals with non-halogenated solvents used in parts and
equipment cleaning and will cover the following:
o Types of solvents used
o Generation and properties of used solvents
o Options for reuse/recycling
o Waste reduction practices and examples
TYPES OF SOLVENTS USED
Hydrocarbons
Hydrocarbon solvents used for parts and equipment cleaning may
be derived from petroleum, coal tar or natural sources.
Petroleum and coal tar products include the following:
o Aliphatic Naphtha such as
- VM&P Naphtha
Mineral Spirits (low and high flash)
\
o Aromatic Naphtha
o Toluene
o Xylene
o Isoparaffinic Solvents
The most common natural hydrocarbon solvent is turpentine. Some
proprietary solvents may contain mixtures of some of the above
along with lanolin (to reduce skin irritation), detergents (for
water rinsing), colorants, perfumes and other additives.
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Paint Thinners
Paint thinners vary in composition to suit the specific paints
used. These types of solvents can contain one or more of the
following hydrocarbon or oxygenated materials:
o Petroleum or Coal Tar Naphtha
o Isoparaffinic (odorless) Solvents
o Toluene
o Xylene
o Ketones
- MEK (Methyl Ethyl Ketone)
- MIBK (Methyl Isobutyl Ketone)
Others
o Esters
Ethyl Acetate
- Butyl Acetate
o Alcohols
- Methyl
- Ethyl
Isopropyl
o Glycol Ethers
Cellosolve (Butyl, etc.)
Paint thinners are included because cleaning of parts and
equipment may often preceed painting and many of you might wish
to recycle thinners along with other solvents.
Other Materials
For the sake of completeness, mention should be made of other
organic and inorganic materials used for parts cleaning. These
are heavy-duty cleaners and paint strippers, as noted below:
o Organic Materials
These are generally mixtures of three or more of the following
solvents:
- Methylene Chloride
- Mineral Spirits
Toluene and/or Xylene
Ketones
Esters
-------
Alcohols
Phenol or Cresols
Glycol Ethers
- Wetting Agents
Suppliers produce proprietary mixtures which may also contain
surfactants, colorants, perfumes, etc. Since the above are
mixtures, it is not common practice to recycle these materials
in-house, but there is no reason why large volume users could
not do so. However, the recycled product should be reformulated
and thus the recycler must be knowledgeable in this technology.
o Aqueous Systems
Acid and alkaline solutions have been used for heavy-duty
cleaning for many years. Included in these categories are
organic amines, which are alkaline ammonium type compounds.
This paper will not cover recycle of these materials.
GENERATION AND PROPERTIES OF USED SOLVENTS
Generation Processes
Used solvent may be defined as any solvent contaminated with
other liquids and/or solids which render it unsuitable for its
intended purpose. Cleaning solvents are generally used in
operations involving spraying, physical or vapor washing,
dipping, hand brushing, etc. The major contaminants are fuels,
oil, grease, water, dirt, metals, paint and other substances,
depending upon the usage.
Cold Cleaning - The major non-vapor methods for cleaning parts
and equipment involve the following:
o Wash Stations - in this operation, solvent is generally
circulated by pump and the part washed continuously with a
stream of liquid. Dissolved materials accumulate in the
solvent, and solids are often removed with screens or
filters.
o Spray Booth - solvent is aspirated from a container, mixed
with air and impacts the part to be cleaned. The sprayed
solvent is collected and recirculated. Soluble materials
accumulate and solids are removed as noted above. Organic
vapors are generally carried out the exhaust and may or may
not be collected and recycled.
o Dip Tank - a large container of solvent is used for immersion
of the part in solvent. Mixers may be added to accelerate
cleaning. As above, soluble and insoluble materials
accumulate. Some solids may settle out.
o Hand/Bucket Cleaning - this is the simplest operation, and
commonly used by small operators. Brushes or rags are often
used to remove tough dirt.
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In all of the above processes, the solvent continuously degrades
in quality because of accumulation of both soluble and insoluble
materials. The amounts of various soluble and insoluble
contaminants allowed to accumulate before changing solvent are a
function of process requirements.
Vapor Degreasing - In vapor degreasing, the parts to be cleaned
are suspended above the liquid and are cleansed by warm vapor
condensing on the component. The condensed solvent and
contaminants are returned to a reservoir where water, dirt, oils
and other contaminants are collected. Clean vapors are
continuously available to wash the parts. Solvent is changed
only when contaminants and sludge build up enough to interfere
with vapor cleaning. Many units have separate solvent
distillation equipment as an integral part of the system. Other
speakers will discuss this technology in detail.
Properties of Used Solvents
Typical properties of used and virgin (or recycled) hydrocarbon
solvent (Mineral Spirits) are given in Table 1. This example
would be typical of usage for cleaning gasoline engine parts.
The major contaminants are as indicated below.
o Gasoline - this is indicated by the low flash point and low
boiling (less than 320 F) compontents. The used solvent may
contain 10-20% of gasoline.
o Water - water can be detected by various means. In the
example given, it might show up as a separate fraction during
the distillation. It would also be detected in the Water,
Oil and Sediment Test.
o Oil and Sediment - dissolved lube and other oils would be
detected in this test as well as sediment. By proper
distillation, the contaminants can be removed and the
reclaimed solvent will meet new or virgin product specifica-
tions.
Other pure organic materials which might be used as cleaners
such as MEK, Ethyl Acetate and others, might have similar
contaminants, and can be reclaimed to original specifications.
Paint thinners are a special case. Since thinners are blended
products and formulated to meet specific volatility and
solubility requirements, their reclamation for use as paint
thinners is not generally recommended. However, used paint
thinners are mainly generated from cleaning of brushes, spray
guns and other application equipment. For these purposes,
product specifications are not usually of significance.
Thus, used paint thinners can readily be reclaimed either by
gravity settling, filtering, distillation or other means.
Reclaimed paint thinner is usually sastisfactory for cleaning
equipment, but is not recommended for thinning paints.
-------
TABLE 1
PROPERTIES OF USED AND RECYCLED MINERAL SPIRITS
Test
Flash Point,TCC, F
Distillation, F
IBP
10%
20%
30%
40%
50%
60%
70%
80%
90%
FBP
Residue
Chlorine Content
Water, Oil &
Sediment, %
Appearance
Test Method
ASTM-D-56
11 D-86
ASTM D-95
Visual
USED
Solvent
<100-120
150-330
150-340
170-340
300-345
320-350
325-350
330-370
340-390
350-400
400-600
Above 500
30 Vol % (Max)
2-20
Brown/Black
Reclaimed
Solvent
102-110
315-330
320-340
325-350
330-365
350-400
2-5 Vol %
Clear /White
-------
OPTIONS FOR REUSE AND RECYCLING
Consideration of options for reuse and recycling of solvents
should include segregation practices, substitutes and down-
grading, equipment requirements, costs and environmental
regulations. These concerns are discussed below.
Increasing Reuse and Recyclability
Segregation - Segregation of solvents is one of the most
important management steps impacting on reuse and recyclability.
Past practices have often neglected segregation and changes are
sometimes difficult to implement. What to segregate depends
upon what downstream operations will be used. Generally,
solvents need to be strictly segregated by each individual type.
Mixing solvents often makes in-house recycling impossible.
Proper labelling and/or color coding and adequate containers for
collection of used solvents enhances segregation.
Substitutes - Replacement of one solvent for another is often
easier said than done, but it needs to be considered and can
lead to easier recycling. Several examples follow.
If chlorinated solvents are used for cleaning electrical parts
and hydrocarbon solvents for machine parts, it may be
appropriate to use a hydrocarbon solvent for both to simplify
recycling. While hydrocarbons are often used for both, some may
not prefer to use these solvents because they evaporate more
slowly and are flammable.
Ethyl Acetate is sometimes used for cleaning purposes.
Replacement with a hydrocarbon solvent can often provide similar
results and simplifies reclamation.
Proprietary hydrocarbon solvents often contain emulsifiers,
lanolin, colorants, odorants, etc., which may or may not be
essential to the cleaning process. Recycling this type of
mixture reclaims only the hydrocarbon fraction. Thus, the
recovered material is not the same as the proprietary solvent.
Reformulation of the solvent can be done by a knowledgeable
person, if desired. The ingredients noted above may or may not
be essential, as noted below.
Emulsifiers - are used to aid in solvent penetration of
water-wet oil, grease or dirt. The emulsifiers also enable the
solvent to be washed off with water. If these properties are
not essential, emulsifiers are not needed.
Lanolin - is added to provide residual oil, thus reducing skin
irritation and dryness caused by contact with the solvent. This
ingredient is not essential to the cleaning process and solvent
users should wear gloves or use a hand cream after contact.
Colorants, Odorants - and other ingredients are generally added
for product identification and customer acceptance. While these
-------
factors can be of some importance, they are not essential for
cleaning purposes.
Aqueous Emulsion Systems - have been offered as substitutes
for cleaning solvents and are claimed to be effective for
cleaning engine and electrical parts. These systems may be
satisfactory for a number of applications. However, there are
two major concerns. One is that water-based systems may require
drying to eliminate residues. A second problem is disposal of
the dirty water. If significant quantities of oil, grease or
other organic materials are carried off in the water, some
treatment may be required prior to discharge.
Downgrading - In-plant reuse by downgrading is a common practice
where a number of cleaning operations are conducted. Following
are several examples:
o Cleaning of bearings often requires use of high purity,
virgin solvent. Since these bearings are relatively clean to
start with, the used solvent from this operation can readily
be downgraded for use in cleaning dirtier engine components.
o Calibrating fluid used for fuel system components is often a
special grade of mineral spirits. After usage, this material
can be downgraded for other solvent purposes.
Economics - The economics of solvent recycling is dependent upon
the following costs:
o Solvent
o Percent .of recoverable solvent
o Collection and segregation
o Equipment and installation
o Operations
o Quality Assurance/Quality Control
o Disposal
A generalized cost estimate for solvent recovery and payback of
equipment costs is given in Figure 1 for solvents costing from
$l-ll/gallon. It may be seen that both solvent costs and volume
have a significant impact on payback periods. More detailed
cost studies are needed for specific cost/benefit analysis.
Processes and Equipment Us^d
There are a number of pro ;ses utilizing equipment for
separating and recycling ^ed solvents. Most operations for
in-plant use are simple, but a wide range of options are
-------
FIGURE 1
PLOTS OF SOLVENT VOLUMES VS PAYBACK PERIOD (YEARS)
FOR SOLVENTS OF DIFFERENT COSTS
Halogenated)
i.e. MeCl
1000
4 5
YEARS TO PAYOFF INVESTMENT
8
-------
available, where appropriate. These methods are discussed
briefly in this section and another paper covers this subject in
greater detail.
Gravity Separation - Simple settling of solids and water is
often practiced for reuse of solvents. Paint thinners may be
reused many times if solids are allowed to settle. The
supernatent liquid can be removed for cleaning purposes.
Centrifuges are also used to accelerate gravity separation.
Batch Stills - This type of equipment may be described as a
flash, pot or single-plate batch still. The used solvent is
heated, vaporized and the vapors condensed into a ^eparat-
vessel. Solids or high-boiling liquids remain in ihe pc ;>r
distillation vessel as " residue. Liquids boi? up t oout
400 F can be recovered. ~,f mixe liquids are i 1 they .11 not
be separated unless the nal be ng point of a solve r is
about 50-60 F below the aitial . .ling point c the of jr
solvent.
There are numerous suppliers of this type of equipment. Major
design variations include the following:
o Size - from 5-500 gallon capacity
o Heating
Electrical
Steam jacked
Direct steam injection
Heat transfer fluids
o With or without vacuum attachment
o Materials of construction
o Clean out
Bottom
- Side
Top
Lift-out trays
Plastic bag liners
o Controls
Costs range from $2-3,000 for 5-gallon units to well over
$100,000 for the largest stills. These units are capable of
reclaiming solvents to purity standards meeting or exceeding new
product specifications.
Fractionation Units - For separation of solvent mixtures,
fractionated units may be required. These are generally
custom-made and can be provided to meet almost any separation
requirement. Size, efficiency and design can be varied to suit
-------
the needs. Costs generally range from $30,000 and up.
Thin Film Evaporators - This type of unit is a variation of
flash stills in which a. thin film of the used material is
deposited on a rotating, hot metal surface. The solvent is
flashed off, vaporized and either condensed or passed on to a
fractionating unit for separation of specific solvents. These
units are very versatile and specially suited for viscous
liquids. Costs range from about $30,000 and up.
Vapor Degreasers With/Without Recycle - For continuous cleaning
operations, and those desiring excellent solvent penetration,
vapor degreasers are often preferred. Only the vapors contact
the parts and condensate is returned to a sump. Some designs
have condensers around the sides of the vessel and others at the
top. Fresh, clean solvent is continuously vaporized to clean
parts. In systems without internal recycle the solvent can
become contaminated with components that vaporize with the
solvent to reduce cleaning effectiveness. To avoid this, the
dirty solvent may be recycled in a separate unit where the
contaminants are removed. Generally, vapor degreasers are
fairly large units containing from about 50 to several hundred
gallons of solvent. Costs are also proportionately large
ranging from $100,000 and upwards.
Toll Recyclers - A variation of in-plant recycling can be
accomplished by toll recyclers. While the solvent is not
recycled on-site, the solvent is replaced on-site. Solvent wash
stations are often serviced by companies in this business.
Service charges may vary from 50-90% of new solvent costs.
HAZARDOUS WASTE REDUCTION PRACTICES AND EXAMPLES
Audit
Any waste reduction program should start with an audit. This
can be a do-it-yourself activity or larger facilities may wish
to hire an outside consultant. The basic components of a waste
audit are outlined in Table 2 and a format for actual use is
given in Table 3. Audits should be conducted by personnel
familiar with the solvents used, process operations, handling,
treatment and disposal options. Several illustrative examples
follow:
o Poor Material Selection
At a large shop, a decision was made to use a proprietary
solvent when a less expensive non-proprietary solvent
would have saved money and been easier to recycle.
A salesman recommended replacement of a chlorinated
solvent by an odorless paint thinner for engine parts
cleaning. The user did not realize that common mineral
spirits would have done a better job and cost about 50%
less.
-------
TABLE 2
WASTE AUDIT OUTLINE
Step 1 - Collect Information
o Tabulate existing data
o Mass balance assessment
o Check completeness of data
Step 2 - Evaluate Waste Handling
o Raw materials
o Housekeeping
o Costs
o Sources
o Practices of personnel involved
Step 3 - Management Alternatives
o Approach for each waste
o Employee requirements and training
o Housekeeping improvements
o Segregation
o Capital investments
o Reformulation
o Reuse
o Technical, economic and liability assessments
Step 4 - Review and Update
o Assess progress
o Track and assess changes in
Raw materials
Processes
Products
Technology
Regulations
-------
TABLE 3
STANDARD WASTE AUDIT FORMAT - AUTOMOTIVE REPAIRS
o Name and location of shop or business
o Name of audit personnel
o Date of audit
o Type of Shop
Automotive repair
New car dealer
Diesel repair
Transmission repair
- Brake/muffler shop
Radiator service
Alignment
Suspension/chassis
Scheduled maintenance
Quick lube changes
- Body/painting
o Size of shop
Vehicles serviced per week
- Number of service bays available
o Services provided
o Number of employees
o Raw materials used
o Raw material storage (complete for each item)
- Raw material (brand name/common name)
Item number
Volume in inventory
Describe usage
Describe disposal practice
Describe storage facilities
(i.e.) 55-gal drum
Containers (volume)
Above or underground tank,
Covered/open
Indoor/outdoor
Secured
Delivery system
(i.e.) Gravity
Funnel
Pump
Material control practices
(i.e.) Stockroom attendant
Access (limited/unlimited)
Signout sheet
-------
TABLE 3 (Continued)
o Material usage (describe for each type)
Sink (size/description/location)
- Dip tank (size/description/location)
- Jet spray (size/description/location)
Spray hood (size/description/location)
o Waste material management
Segregation practiced (if yes, describe)
If no segregation, describe practice
Options available for segregation
Storage facilities (describe)
Disposal practices
(i.e.) On-site recycling
Serviced by equipment leasee/maintenance contractor
Picked up by contractor
Disposed in municipal solid waste
Disposed to municipal sewer
Disposal costs
(i.e.) Oils
Solvents
Res idues/sludges
Anti-freeze
Aqueous materials
Other
o Material losses
o Provide a schematic for waste management practices
o Prioritized sites of significant waste generation
o Waste management options
o Source reduction options
Material substitutions
Process changes
Housekeeping
o Regulatory compliance evaluation and needs
o Recommendations for improved management
-------
Selection of the Best Option
After completion of an environmental audit and consideration of
viable options, economics and applicable regulations, selection
of the best option should be relatively easy. The major
management practices which need to be selected are discussed
below.
Segregation - Uncontrolled mixing of used solvents yields waste
slops with little or no economic value and little chance of
recycling. In addition, because waste mixtures are often
designated as hazardous wastes, their disposal is becoming more
costly. A summary of recommended options for a number of
solvents is given in Table 4. Segregation by each individual
solvent is generally the best means of optimizing recovery and
minimizing costs. Alternate options are usually less desirable
and not as cost effective.
o Example
We have all seen or heard of locations with vast numbers of
drums of mixed solvents and other materials. These were
accumulated because plant operators were not concerned about
disposal or were not willing to pay disposal costs. My
experience has been that many plant managers believed these
drums contained valuable materials which should have been
marketable, but realistically, were not.
Many superfund sites were created because of improper management
and disposal. With a minimum of segregation, many of these
waste drum fields could have been disposed to cement kiln
operators who had capabilities for burning a variety of
mixtures.
Collection - Adequately marked containers must be provided to
encourage and ensure proper collection and segregation. Good
practice includes color coding, visible and legible labels, and
a manifest system. Color coding can simplify identification and
is easy to implement. Labels can be hung on walls, placed on
top of a container or stencilled on collection drums. Labels
stencilled on both sides of a container work well, those only on
top can be obliterated by a spill. A manifest should be used
even for internal recycling. The generator should fill out a
manifest form, attach it to the container, and have a copy sent
to the recipient and to a central control person.
Recycling - Recycling or reclamation of used solvents can be
accomplished with in-house equipment and facilities for almost
all pure solvents, but is generally not practical for some mixed
solvents. This discussion covers solvents segregated and
collected after use as well as solvents recovered in vapor
recovery units.
Recyclable and Non-Recyclable Solvents - Solvents which can be
recycled readily are listed in Table 4. These materials can
-------
TABLE
SUMMARY OF SEGREGATION RECOMMENDATIONS FOR RECLAMATION AND DISPOSAL OF SOLVENTS
SOLVENT
SEGREGATION GUIDELINES
Hydrocarbons
Calibrating Fluid
Coal Tar Naphtha
Dry Cleaning Solvent
- 100F Min.Flash Point
- 140F Min. " "
Naphtha, Aromatic
Thinner, Paint
Xylene
Agitene
Naphtha, Aliphatic
Toluene
Preferred Option
Segregate and reclaim
for original use
Alternate Options
Mix and recL.jn
as a general
cleaner or wash
solvent
DO NOT MIX
WITH ABOVE
Can mix with
chlorinated and
oxygenated solvents
for disposal to
selected cement kiln
operators
Halogenated
Methylene Chloride
Tetrachloroethane
1,1,1-Trichloroethane
Trichloroethylene
1,1,2-Trichloro-
1,1,2 trifluoroethane
Oxygenated
Acetone
Ethyl Acetate
Ethyl Alcohol
Isopropyl Alcohol
Methyl Alcohol
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Segregate and reclaim
for original use
Segregate and reclaim
for original use
Mix and reclaim
as a general
cleaner or wash
solvent
-*
All chlorinated,
hydrocarbon and
oxygenated solvents
can be mixed and disposed
to selected cement kiln
operators
Can mix with all chlorinated and
hydrocarbon solvents for disposal
to selected cement kiln operators
-------
generally be recycled to meet original solvent specifications.
In addition to those noted above, paint thinners can also be
recycled. Since most thinners are mixtures and lose volatile
solvents in use, the recycled solvent is not the same as virgin
material. Thus, reclaimed thinner should not be used as a paint
thinner but can be used to clean paint equipment.
Typical non-recyclable solvents are noted below, along with
brief comments.
Carbon Removers and Paint Strippers
These mixtures are generally quite toxic since many contain
phenolic compounds and thus in-house recycling is not
recommended.
Proprietary Solvents
Many proprietary cleaning solvents contain additives (as noted
above) which are not recovered in distillation. Therefore, the
recycled material is not the same as the original solvent.
Processes and Equipment Used - The major processes and equipment
used are discussed briefly below:
Gravity Separation - Used mainly for paint thinners.
Batch Stills - Many companies manufacture, sell and service
batch stills for in-house recycling of solvents. A list of the
major suppliers is given in Table 5 along with some general data
on the types, ranges, features and costs of this equipment.
These units will not separate solvents and must be used for only
one solvent at a time. They can be used for a variety of
solvents with cleaning between batches.
o Examples
NAVY-At the Naval Shipyard in Portsmouth, Va., a 15-gal/
day batch still has been successfully used to recover
mineral spirits and paint thinners. Savings amount to
about $15,000 per year and the equipment was paid off in
less than six months*.
AIR FORCE-Robbins AFB has a number of different units for re-
cycling over 50,000 gallons per year of various solvents.
Total savings are reported to be over $600,000 per year.
* This information was obtained from an article dated 11/5/84
that appeared in the Virginia Pilot (a local Portsmouth, VA,
newspaper).
-------
TABLE 5
SUPPLIERS OF SOLVENT RECYCLING EQUIPMENT SUITABLE
FOR ON-SITE RECLAMATION - SINGLE-PLATE PACKAGED STILLS
Supplier
Alternative Resource
Management
7134 S. Yale(Suite 400)
Tulsa, OK 74136
918-495-0535
Solvent
Thruput Capacity Heating
G/Hr(l Gallons Options
1.5-100 5-100 Electric/
Steam
Cooling Explosion Cost Solvent Types
Options Proof $K Designed for Comments
Refrig/
Water
Yes
2.5- All
100+
Atmospheric &
Vacuum Models
Available
Baron Blakeslee
2001 N. Janice Ave.
Melrose Park, II. 60160
312-450-3900
10-120 8-95 Electric/ Refrig/ No 5-8 Halogenated
Steam Water
Branson Cleaning
Equip. Corp.
P. 0. Box 768
Shelton, Ct. 06484
203-796-0400
12-60 10-60 Electric/ Refrig/ No 4-10 Halogenated
Steam Water
BR Instrument Corp.
P.O. Box 7
Pasadena, MD. 21122
301-647-2894
1-2 3-6 Electric Water Yes 9-12 All
For Lab
Operations
DCI International
1229 Country Club Rd.
Indianapolis, IN 46234
317-271-4001
Detrex Chemical Ind.Inc.
P. 0. Box 501
Detroit, Mi. 48232
313-358-5800
Disti Inc.
131 Prince St.
New York, N.Y. 10012
212-505-0611
Finnish Eng. Co.
(Extratec)
921 Greengarden Rd.
Erie, Pa. 16501-1591
814-455-4478
250 250
30-180 50-200
Dir. Steam Water
Injection
Electric/ Water
Steam
Yes N/A All
2-70 10-50 Steam/
Hot Oil
Water
15-380 5-50 Electric/ Water
Steam
No
5-10 Halogenated
Yes 8-54 All
Yes 5-80 All
For Removal of
Solvents from
Oils
Make a Wide
Range of ATM.
& VAC. Models
-------
TABLE 5(Continued)
Finishing Equip. Inc.
3640 Kenneber Dr.
St. Paul, Mn. 55722
612-452-1860
N/A* N/A Electric/ Water No
Steam
N/A Halogenated
Giant Distillation &
Recovery Co.
3156 Bellevue Rd.
Toledo, OH 43606
Hoyt Corp.
Forge Rd.
Westport, MA. 02990
617-636-8811
1.5- 5-60 Electric/ Water Yes
10 Oil
4-8 25-50 Oil
Water No
5-100 All
Atmospheric &
Vacuum Models
Available
N/A Halogenated Also Make Vapor
Recovery Units
Lenape Equipment Co.
P. 0. Box 285
Manasquan, N.J. 08736
201-681-2442
4-45 5-30 Electric Refrig/ No
Water
3-20 Halogenated
National Ultrasonic N/A
Chicago, II. 60626 (2)
312-465-6780
N/A
N/A
N/A
N/A N/A Halogenated
Phillips Mfg. Co.
7334 N. Clark St.
Chicago, II. 60626
312-338-6200
5-125 15-125 Electric/
Steam
Water
No
7-15 Halogenated
Progressive Recovery Inc 5-35
1976 Congressional Dr.
St. Louis, Mo. 63146
314-567-7963
5-25
Hot Oil
Water
Yes
8-30 All
Ramco Equip. Co.
32 Montgomery St.
Hillside, N.J. 07205
201-687-6700
25-200 30-135 Electric/
Steam
Water No 7-20 Halogenated Also Make
Custom Designs
Recyclene
1910 Trade Zone Blvd.
San Jose, Ca. 95131
408-945-8600
2-20
15-35
Electric/
Heated
Oil
Water
Yes
4-21 All
Vaco Solv Co.
P.O. Box 26147
Cincinnati, OH. 45226
513-321-9178
1.6-10 5-60
Electric
Air
Yes
10-3 All
No Cooling
Needed
Westinghouse Elec. Co. 15-30
Box 300
Sykesville, Md. 21784
301-795-2800
18-50
Electric
Refrig/
Water
No
7-10 Halogenated
* N/A = No Available Data
-------
INDUSTRIES-Many industries have successfully recovered
solvents with in-house units, thereby saving valuable
resources, and eliminating or drastically reducing
disposal requirements.
Fractionation Units
Custom-made fractionation units can be obtained from companies
such as those noted in Table 6.
Thin Film Evaporators
To recover solvents from high viscosity fluids, thin film
evaporators or wiped surface evaporators are generally
recommended. In some cases, these units may be followed by
fractional distillation units for better separation of solvents.
Suppliers of this type equipment are noted in Table 5-6.
o Example
NAVY-The Navy has been recovering Freon 113 at Portsmouth,
Virginia Naval Shipyard for many years and saving $20,000-
30,000 per year.
Vapor Degreasers With and Without Recycle
Vapor degreasers are usually large units which generally have a
freeboard area for condensing vapors above the vapor cleaning
section. Some units contain internal solvent recycle systems,
thereby minimizing the need for cleanout. Most vapor degreasers
utilize halogenated solvents.
Disposal - Disposal of sludge bottoms from most distillation
units is still necessary. Experience has shown that for
solvents used in precision cleaning, only a small volume of fine
solids is obtained. These solids can often be disposed as a
non-hazardous solid waste. At the other extreme are sludges
from paint thinners. These residues can be taken to dryness and
disposed as a hazardous waste.
Interesting exceptions are still bottoms from mineral spirits
used for engine cleaning. The residues are mainly oils and can
often be blended in with waste oils for disposal.
In almost all cases where solvents are recycled, some residues
remain which have to be disposed as hazardous wastes. Options
include land filling, incineration, encapsulation, blending with
asphalt and others.
CONCLUSIONS
In-plant recycle and reuse of solvents can be achieved for most
solvents. The major concerns are:
- Quality and quantity of used solvents
-------
TABLE 6
SUPPLIERS OF SOLVENT RECYCLING EQUIPMENT SUITABLE FOR ON-SITE
RECLAMATION - CUSTOM BUILDERS OF FRACTIONAL DISTILLATION UNITS
Supplier
Advanced Process Systems
10400 Linn Station Rd.
Suite 310
Louisville, KY. 40223
Artisan Ind. Inc.
73 Pond Rd.
Waltham, Ma. 02154
617-893-6800
Chem-Pro Equip. Co.
27 Daniel Rd.
Fairfield, N.J. 07006
201-575-1924
pistillation Eng. Co.
'105 Dorsa Ave.
Livingston, N.J. 07039
201-992-9620
Ferguson Ind. Inc.
1900 West Northwest Hwy.
Dallas, Tx. 75220
214-556-0010
Finish Eng. Co.
921 Greengardens Blvd.
Erie, Pa. 16501
814-455-4478
Progressive Recovery Inc.
1976 Congressional Dr.
St. Louis, Mo. 63146
314-567-7963
Thruput
Gal/Hr
(1)
5-100
Type of Equipment Available
Solvent
Capacity Explosion
Gallons Proof
10-50
5-50
5-50
N/A
(2)
5-50
3-30
5-100
10-50
10-50
10-50
N/A
10-50
10-50
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Price
$K
20-50+
20-30+
20-30+
20-30+
20-30+
20-30+
20-40+
(1) For the lowest volatility solvent
(2) N/A = No data available
-------
TABLE 7
SUPPLIERS OF SOLVENT RECYCLING EQUIPMENT SUITABLE
FOR ON-SITE RECLAMATION - THIN-FILM EVAPORATORS
Supplier
Alpha Laval Inc.
2115 Linwood Ave.
Ft. Lee, N.J. 07024
201-592-7800
Artisan Ind. Inc.
73 Pond St.
Waltham, Ma. 02154
617-893-6800
Brighton Corp.
11861 Mosteller Rd.
Cincinnati, Oh. 45241
513-771-2300
Luwa Corp.
P. 0. Box 16348
Charlotte, N. C. 28216
704-394-8341
Progressive Recov. Inc.
1976 Congressional Dr.
St. Louis, Mo. 63146
314-567-7963
Solvent
Thrput Capacity Heating
Gal/Hr* Gallons Options
Hot Oil
5-50 5-50 Steam/
Oil
7.5-200 5-200 Steam/
Hot Oil
50-1200 Cont. Steam/
Hot Oil
15-300 15-300 Steam/
Hot Oil
Price
Cooling Range
Options $K
Refrig./ 50+
Water
Water
Water
Water
Water
50-130
18-43
25-50+
40-120
* For the lowest volatility solvent
-------
Segregation and handling practices
Selection of recycling equipment
Management practices
Costs for operation and maintenance
After completion of an environmental audit and review of the
above, experience has shown that in-house recycling is often the
most cost-effective and environmentally-preferred option.
-------
Off-site Reclamation of All Solvents
Brian R. Dawson
-------
SOLVENT WASTE REDUCTION ALTERNATIVE SEMINAR
Commercial (Off-Site) Solvent Peclaniaticr
by: Brian P. Dawson
Solvent Resource Recovery, Inc.
(division of Chemical Waste Management, Inc.)
Solvents are an important part of most industrial
operations. Almost ell plants use solvents, usually for
cleaning, degreasing, painting, paint stripping, or extraction
purposes. Therefore, the problem of proper management of solvent
wastes is a widespread concern. There are several disposal
methods available to solvent users, but in most cases the most
environmentally sound and economical choice is not to dispose of
the solvent at all, but to recycle it.
Tf we briefly review the generally accepted priority list of
hazardous waste management, we see that first, it is incumbent
upon generators of waste to institute a program to reduce the
amount of waste generated. Second, after the amount of waste
generated has been minimized, recycling is considered the next
most appropriate alternative. Third on most lists is
incineration, and fourth is chemical or biological treatment to
render the waste non-hazardous. Landfills, deep-well injection
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and other methods fall further down the list.
/> s you can see, recycling is ranked very high on the
priority list of alternatives for hazardous waste management.
This is because it accomplishes two very important
objectives... one, it further minimizes the quantity of waste to
be handled, and two, it conserves precious natural resources.
Waste min im i zat ion is accomplished because the reclaimed solvent
becomes a usable product, no longer a waste. Natural resource
conservation is accomplished because the petrochemical building
blocks necessary for virgin manufacture are not required, and the
utility r equ i r ements (such as electricity and steam) to reclaim.
are a fraction of the requirement for virgin manufacture.
There are many types of solvents that are commonly recycled.
Host prevalent are paint solvents. Almost any industrial process
involves painting, and requires solvent for application, cleaning
of paint masks, spray equipment, and line flushing. Even the
manufacture of paint requires solvents for cleaning of mixing
equipment, and transfer lines. The solvents generally used for
these purposes are various mixtures of ketones (such as acetone,
methyl ethyl ketone, and methyl isobutyl ketone), esters (such as
ethyl, acetate, n-butyl acetate, and isopropyl acetate), alcohols
(such as ethanol, isopropanol, and n-butanol), and aromatic
hydrocarbons (such as toluene and xylene).
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In the metal working industry, lubricating oils, cutting
oils, and greases are used in the processes, and must be removed
prior to further work, such as plating or painting. The solvents
used for this type of cleaning include chlorinated hydrocarbons
and p etroleum distillates such as various mineral spirits,
toluene, and x
In the printing industry, solvents are used as ink
additives, and also for cleaning of rollers and presses.
Commonly used are alcohols, esters, and aromatic hydrocarbons, as
well as various mixtures thereof.
The electronics industry uses many solvents for cleaning,
stripping, defluxing, and even as a photo-resist developer for
printed circuit boards. Generally used are chlorinated and
fluorinated hydrocarbons.
There are also thousands of snail commercial establishments,
such as auto repair garages, auto body shops, and dry cleaners
using solvents such as petroleuir, hydrocarbons, paint thinners,
and perchloroethylene.
Virtually all solvent use applications are physical in
nature - not chemical. In other words, the chemical structure of
the sc vent is not altered. It is merely contaminated, so the
purpose of solvent reclamation is to remove the impurities,
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making the solvent available for reuse. The reclamation process
also does not chemically alter the solvents, therefore, there is
no limit to the number of times a solvent may be recycled or
reused.
Cn-site reclamation, where practical, is generally preferred
to off-site reclamation, in order to avoid the risk and liability
of transportation. If not practical, though, due to economic oc
cuality limitations, off-site reclamation should be considered as
your next alternative.
There are two basic types of off-site or commercial solvent
recycling available. Cne is custom toll recycling, where the
generator's spent solvents are kept segregated, and batch
processed separately to the generator's specification, then
returned for n-'use. V'/hile the requirements vary among different
processors, the minimum batch size is generally 1,000-2,000
gallons, so this option is usually limited to larger generators
of waste.
The batch size limitations are caused by processing
equipment size, economies of scale, and sometimes transportation
costs.
The processing equipment is engineered to handle large
volurres of waste, and small batches will not "wet" the system,
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causing a very low percentage of recovery. If the distillation
system is designed to circulate 50C gallons through the heat
exchanger, a 1,000 gallon batch of waste processed can yield a
rcaxirum of 50% recovery. However, a 2,000 gallon batch can yield
75% recovery, a 3,000 gallon batch can yield 83% recovery, a
4,OCO gallon batch can yield 80%, and so on.
Economies of scale realized from larger batch sizes come
from the charge or fill time, heat up time, still bottoms pumping
time, and cleanout tiire. Each of these steps are necessary for
all hatches, and require approximately the same amount of time
whether processing 1,000 gallons or 4,000 gallons.
Transportation costs are often comparable, whether shipping
full truckloads or partial truckloads, so the larger the quantity
shipped translates to a lower .cost per gallon.
If the above limitations can be overcome, significant
benefits can be realized. The generator can be assured that the
reclaimed solvent returned is not contaminated with any solvent
foreign to his system, since the waste is kept segregated through
all processing steps, thereby simplifying quality assurance and
quality control. The generator is also dealing with a "known"
entity, i.e. the solvent returned is coming from solvent waste
already used in his operations. This can simplify SAPA Title III
and Kcrker Fight-to-Know concerns.
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Economics of custorr toll recycling are governed by four key
factors. The first is processing cost. Processing costs not
only entail the usual items such as labor, utilities, and
equipment i n ve s tme n t, but also the administrative costs
associated with maintaining environmental compliance. Processing
costs are also affected hy specifications required. The narrower
or tighter the specification for the reclaimed solvent, the
higher the cost, especially if drying is required. Second is the
disposal cost of the still bottom residues, or otherwise
unrecovered portions of the waste stream. Third is
transportation cost. Last, though probably most important, is
the percent recovery, or yield. The higher the yield, the lower
the unit processing cost, the lower the disposal cost, and the
lower the unit transportation cost.
Generally, after all costs are considered, the reclaimed
solvent is returned to the generator at a price similar to or
slightly lower than virgin solvent purchase. Vvhile this may not
seem to be very motivating, we must not forget to consider the
alternative - if the spent solvent is not recycled, it must be
disposed, and disposal costs are very high these days.
Therefore, recycling avoids the disposal alternative, and makes
the natural resource available for reuse.
The second fortr of commercial reclamation is known as "open
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market" recycling, where the spent solvents are co-mingled with
like or similar wastes from many generators, and processed to
specification for resale and reuse in the marketplace as refined
solvent. This option is available to virtually all generators of
spent solvents, as long as the recycling facility offers the
service (some companies specialize in only custom toll
recycling), and there is a resale market for the refined product.
One other potential limitation involves waste segregation - if a
generator is using sevetal different solvents in different parts
of his operation, and co-mingles the waste, there is a strong
likelihood that the refined solvent from that waste may not be
suitable for resale, leaving disposal as the only alternative.
Though there are exceptions, most solvent waste streams are
suitable for recovery. Since the recycler will be deriving
revenue from the resale of the product, the benefit to the
generator can be a lower disposal cost. Also, the generator can
be assured that his waste is being managed in an environmentally
acceptable manner, with the corresponding benefit of natural
resource conservation.
The charges assessed for the management of spent solvents
through "open market" recycling vary with the relative resale
value of the refined solvent. The g >ral "rule of thumb" in the
ir jstry is that refined solvents se.. ing for less than $0.20 per
pound are marketed at 8C% of virgin price, and those selling for
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more than $0.20 per pound are marketed at 90% of virgin price.
Since the costs associated with recycling have no relationship to
market price, in order for a recycler to make a profit on low
priced reclaimed solvent, disposal charges must be assessed.
While the charges will vary depending on quantity and
transportation, for most non-chlorinated solvents the disposal
price i.9 in the range of $50-$100 per drum.
Host chlorinated solvents have a higher resale value, and
under certain c i r curstances, come generators are even paid for
their chlorinated waste. Fore frequently, though, the charges
are in the range of free disposal to $50 per drum.
The three key factors affecting the disposal cost (other
than chlorinated vs. non-chlorinated) are quantity,
transportation, and character of the impurities. It takes
exactly the same amount of time to process the paperwork and
p-erfornr. the analyses for one drun as for forty drums, so the more
drun.s shipped/received have a lower unit processing cost.
Transportation costs are affected in a similar manner. Perhaps
the single most key factor, though, is the character of the
impurities. If water is present, in the waste, it too then
becomes a waste that rrust be properly managed, at high cost.
Solid, or "nop-pumpahle" impurities are not recoverable, and must
be properly disposed at high cost. Last, foreign objects, such
as rags, gloves, nuts, bolts, filter cartridges, pop cans, paper
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cups, etc. present in the waste must he separated and properly
disposed as waste, usually by incineration. When waste
minimization techniques are being considered, care should be
taken to avoid some of these impurities, as they add significant
cost to the processing of solvent waste.
Technologies exist today to assure high quality reusable
solvent. The prevailing method of processing is distillation or
vaporization. All recyclers use the same basic systems and
technology, but they apply those systems in a highly-
individual i eed manner.
Many solvents can be processed into a reusable state by
simple vaporization. This is usually done in a pot still or
thin-filir evaporator.
In the pot still, the spent solvent is charged to the
systen., then heated to boiling by steam or hot oil heat
exchangers. The heat exchangers can be either internal or
external. Cnce boiling, th<= solvent vapors exit the system to a
water cooled heat exchanger, then cooled to a clean solvent
liquid. The non-ve In t i It? residue?, or still bottoms, are then
punced to storage awaiting final disposal. rith strict land
disposal regulations in effect, the usual, most cost-efficient
disposal method is through a /.aste derived fuel program. This is
accon.pl ished by blending the still bottoms to a prearranged
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specification for consumption as a fuel in a cement or
lightweight aggregate kiln. This disposal n.ethod has the
advantage of assuring comparable destruction ratio efficiencies
to an incinerator, tut at sign i f irc-ntly lo\ver cost. Mso, there
is sufficient capacity available in the rr.arket for this, disposal,
while corrr.iercial incineration capacity is limited.
Sin.ilar to pot stills in reclamation technology are thin-
filrr or wipe-filir evaporators. The difference is that while in a
pot still, the spent solvents are "cooked", the thin-filir
evaporator functions by pur ping the waste into the top of the
unit, where it is then spread in a thin layer on the internal
surface by rotating wiper blades. The internal surface is heated
by a stearr or hot oil jacket. Ey exposing the solvent waste to
this heat in a thin Icyer, the organic solvents are flash
evaporated, once again to a heat exchanger, to be condensed as
clean solvent liquid. in these systems, the non-volatile
residues continuously exit the bottom of the evaporator, to be
handled in the sarr.e iranner as pot still bottoms. The advantage
of the thin-filrr evaporator over the pot still is that the batch
size is not limited by the size of the pot, since the systerr. is
fed frorr: an external storage tank, and operated continuously.
£lso, sorre non-volatile residues are subject to cherrical
breakdown when "cocked", which can cause odor or color problems
in the reclaimed solvent. Tf thermal breakdown is not a concern,
the pot still has the advantage of giving higher recovery yields.
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Toth pot. still and thiri-filrr evaporators are often operated
under vacuum, to reduce the boiling point of the solvent, thus
reducing the arrount of energy required, and also enabling the
recovery of sore high boiling solvents.
The disadvantage of both there systems is that they have no
separation capability, other than volatile organics frorr. non-
volatile organic?. Tn other words, all the volatile organic
solvents entering the systems will exit as product. As long as
the solvent waste has been kept properly segregated, and the
recoverable solvent portion is pure, this is alright. Uut if
volatile organic impurities are present in the waste, they will
be present in the reclaimed solvent. This iray cause quality
problems, so to address the situation, some recyclers have
installed fractionating columns.
Fractional distillation is an extremely complex technology,
with several different types of columns, and a vast variety of
sizes anc configurations. The ircst common types of columns are
packed columns (usually with porcelain saddles), bubble cap
columns, sieve plate colurr.ns, and valve tray columns. The taller
the column design, the pore trays, enablinc rrore separation or
clarification capability. As the diameter of the columns
increase, more throughput capacity is obtained.
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Thf underlying principle of operation of all fractionating
columns is the same. The volatile organics are heated by steam
or hot oil by means of internal or external heat exchangers. ?s
the solvent wastes reach the boiling point, the vapors enter the
coluirn. The lower boiling components migrate to the top of the
column, with the colurrn design promoting internal condensation of
higher boiling components, with subsequent migration to the lower
part of the co.lumn. As the lower boiling vapors exit the top of
the column, they are condensed to a liquid. During the initial
start up operation? of a batch run, all the condensed liquid
(clean solvent) is pumped back into the top of the column as
reflux, further promoting internal condensation and migration.
i;hen equilibrium is reached in the system, part of the reflux
condensste is punped to product storage, with the remainder
continuing back to the column. The amount returned to the column
compared to the amount pumped as product is known as the reflux
ratio .
i:hen separating solvents with a narrow spread between their
boiling points, the reflux ratio may he very high - as much as
5:1. This means that for every six gallons boiled out of the
system, five gallons go back, with one gallon of product
produced .
The reflux system, enables a high purity cut of the lower
toiling solvent to be reclaimed. As the lowest boiling component
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is removed to clean product storage, the next highest boiling
component will migrate to the top of the coluir.n. No fractional
distillation is 100% efficient, so there v/ill be a small
intermediate cut of the mixturr of the two components, taken to
separate storage. This n.ay be fed back to subsequent batches.
After the intermediate cut, the next component is removed in
the same n.anner as the first cut, maintaining adequate reflux to
assure separation from even higher boiling solvents. The batch
is thus continued until all sought after solvent components are
reclaimed. The unrecovered residues are then handled in the same
manner as those from pot stills or thin-film evaporators.
«*
Theoretically, any solvent mixture can be separated by-
fractional distillation if the equipment design is adequate.
Practice! considerations of operating economics and equipment
investment generally though, limit efficient separation to
solvents having a boiling point spread of 2C°-30° C. It «hould
be noted that, even this is an improvement over capabilities
available in the recycling industry from twenty years ago. By
variance of solvent waste feed points, reflux ratios, and use of
vacuum, a great deal of flexibility is created to process many
different solvents previously considered either uneconomical or
impractical. Quality refined products are being produced that
can be used in almost all phases of industry, including
pharmaceutical applications to manufacture drugs.
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Subsequent processing may involve extraction, filtering,
r es ta bi 1 i za t ion, or drying,, depending on the refined solvent
specificati en requirements. The most common problem associated
with refined solvent quality is excessive rr>oisture, or water.
f'oisture ccntan>ination may create corrosion problems, or coating
problems with paint solvents, or hydrolytic breakdown problems
with chlorinated solvents. Several techniques are available to
address these problems.
Since water forms an azeotropic, or constant boiling
mixture, with many solvents, those recyclers with fractionating
«*
capability ray use distillation techniques for moisture removal.
Depending on the azeotropic mixture, and the quantity of water to
be relieved, this method can be very effective, though usually
ou i te cost-] y......
Another option available is physical or nechanical removal.
This involves filtering the refined solvent through an absorbing
or adsorbing dessicant, and. there are several methods used.
Anhydrous calcium chloride is sometimes used for this
method, and can hi;- very effective for re i* oval of trace water
contamination. For refined solvents containing less than 0.5%
moisture contamination, calcium chloride can dry them down to 200
parts per million. Disadvantages are that when spent, the
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calciun! chloride cannot be regenerated, creating a potential
disposal problem, and there is the possibility of free halogen
contamination of the refined solvent, causing a potential
corrosion problem.
Another method effective for trace water contamination
removal is ion exchange resin. This method uses adsorption, with
the water nolecules attaching to the resin, and the subsequent
dry solvent passing through. It has repeatedly demonstrated the
ability to reduce moisture levels from 0.2%-0.3% down to less
than 100 parts per million, and has the advantage of being able
to regenerate. A disadvantage, though, is that this method is
not effective on refined solvents with more than 0.5% moisture
contamination.
Probably the b^st available technology today for moisture
removal is the molocular sieve bed. It functions by actually
trapping the water molecules in the interstices of the molecular
sieve, allowing the dry solvent to pass through. This method has
the advantage of being able to handle gross amounts of water
contamination (drying from 5% down to less than 1%), as well as
the trace moisture contaminated solvents (drying from 0.5% down
to less than 200 ppm). It also can be regenerated for continued
use.
From a technical point of view, any solvent can be reclaimed
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to a point where it can be reused. The only limiting factor is
economics, and with disposal costs escalating so rapidly,
recycling is becoming the method of choice for a wider range of
solvents. In seme cases, the cost for disposal is higher than
the original cost of the virgin product, and once a material is
disposed, it is gone forever, with a corresponding loss of
precious natural resources.
Let's look at what happens to your solvent during the
recycling process to assure quality. First, the waste is
collected, in either drums or bulk tank truck transport, and sent
to the recycling facility. There, the waste is analyzed to
verify that the contents agree with the waste manifest. Then the
waste is pumped to hulk storage. When enough material has been
accumulated for an economical run, the waste is processed through
the distillation system. The resulting refined product is then
analyzed again to determine conformance with established
specifications. If further steps are required, such as drying or
restabilization, the product is checked again prior to pumping to
final storage. From there, the refined solvent is packaged to
customer order in either drums or bulk tanker, with yet another
quality control check before shipment. The still bottoms are
also thoroughly analyzed to measure confer nance with fuel
blending specifications.
A typical recycling facility lab is equipped with gas
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chromatographs, Karl-Fischer titrimeters, calorimeters, atomic
absorption spec t r opho t oire t e r s, as well as other ancillary
equipment such as pH meters, color testers, and specific gravity
measurement.
The gas chromatograph is the key analytical tool for quality
control in the recycling lab. Various instruments are available,
but a well-equipped lab will have multiple capability - a unit
with a thermal conductivity detector for macro analysis of
solvent components, a flame ionization detector for analysis of
rnicro (or components in the 100 ppm to 1,000 ppir range), and an
electron capture detector for even greater sensitivity (to check
for trace PCP contamination, for instance). The GC's can also be
equipped with automatic integrators, automatic injection, and
controlled by computer to increase analytical reproducibility and
reliability.
The Karl-Fischer titritr.eter is used to measure water
content. Depending on analytical technique, the instrument may
be sensitive down to less than 50 ppm.
Color testers and pH meters are used for obvious purposes,
since color is occasionally a quality problem for customers, and
r.U can affect corrosion properties of the refined solvent.
The calorimeter is used to measure DTU content of the still
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bottons, with subsequent wet chemistry testing for halogen
content. Both of these parameters are key specifications for
waste derived fuel prograirs.
Another key parameter for still bottoms blending into waste
derived fuels is heavy metal content, such as lead, zinc, chrome,
etc. Typically, the recycler will use atomic absorption
spectrophotometry to measure heavy metals.
If refined chlorinated solvents are intended for reuse in
vapor degreasing, stabilizer content is an important quality
control parameter. t-'hile some individual stabilizers can be
measured by gas chromatograph, a better method for checking total
stabilizer content is through wet chemistry titration of acid
acceptance.
If the recycler carefully follows all the quality control
steps, industry is assured of receiving a quality product,
appropriate for almost any use. In my experience, there are very
few applications where refined solvents cannot be used. While
there are perceptions in the market that refined solvent is not
as good a? virgin solvent, this is very seldom true. Even some
of the obvious differences between the two, such as purity,
color, and odor very seldom, actually affect the performance of
the solvent riurinc rf;'use.
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By dealing with a recycler equipped to service even the
srr.all Generator, the economic and environmental advantages of
recycling can be realized. The solvent recycling rrarket is
relatively mature, and well-established, though in somewhat a
s t * t e of change today. While some companies have been in
business for as long as 50 years, and many for as long as 2C
years, there are very few new entrants to the field.
Dramatically increased regulatory and permitting requirenents
make it very difficult to stay in business, let alone make a new
entry. Five years ago, market estimates indicated about 150
recyclers in business in the United States. Today, that number
is less than 100, and by 1992 is projected to be less than 50.
The trend in the market is towards consolidation, as larger
companies, with greater assets and resources, absorb smaller
companies unable to comply with the regulations.
There will still be plenty of capacity available, though, as
there is no recycler of which T a it: aware that is operating at
more than about 60% utilization. Also, most of the decrease from
100 recyclers to 50 will be via consolidation, i.e. they will be
acquired, and continue to operate, rather than cease to exist.
Therefore, there should be plenty of available opportunity for
generators to take advantage of off-site recycling within their
economic transportation service area, generally considered to be
300-4CC IT lies.
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r«?- have looked at both custom toll recycling and "open
irarket" recycling - the criteria for selecting the proper irethor!
varies with individual needs. A more important consideration,
though, is selection of the proper corrpany to service your
requirements. Several key factors should be pxamined. Since the
hazardous waste generator forever retains ultimate liability for
the waste, and IT. any r. ore of us are now subject to the
regulations, this has far reaching implications, and should weigh
heavily in decidinq where to have solvent waste recycled.
The refined solvent resold in the marketplace is considered
o troc'uct, and is no longer subject to the provisions of FCFA.
rut since no. solvent waste i? ?CC% recoverable, there are
residues which must still be properly managed to minimize risk
and potential liability.
i.
In the cast, nany industrial and governmental waste
generators selected.:, their TSp faci 1 i ty based upon impressive oral
and written assurances and representations of proper procedures,
and have been "burned", these aip.su ranees being no protection
against liability. Then, most firms began requiring copies of
a n r or r i ate' c-errrits from, these facilities being used or
considered for use. Alas, this has proved no more effective, as
most Tucerfund priority sites appear to have beer properly
perritt.ed durinc t.f"? course of their operation. Cnce again, no
crotec-tion fron. lialjilitv.
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now, then, since you as Generators retain ultimate liability
for'the'management of your hazardous, waste, can you minimize the
risks of damage to the environment, or to your company's asset?
and reputation? r.y the way, it IP try considered opinion that.
tho^o of you who rray he categorized as small generators need to
assign as iT'Uch or rrore attention to this decision as does General
Motors, IBM, Xerox, and other corporate giants. As an
illustration, at the Per] in and Farro site in f'ichigan, clean up
costs of ?14 million were pair" by F,7 generators. General rotors'
share was 5?.4- million, Dow Corning'? $1.2 million, FL Industries
5129 thousand, Ford rotor Coni;any $217 thousand, Grand Trunk
Railroad $144 thousand, Monserto $100 thousand. These costs,
having been published in the newspaper,, are errbarrassing to the
coiTipan.i es' involved, as well as damaging to profitability, but
beyonc t>at, there will be no discernible adverse effect. ..Each
considers it an expensive lessor ] ea r.ned, and business life
continues. How Would your company react to such a penalty? Cr
even one of ?5 thousand, $10 thousand, or $50 .thousand'? In some
cases, I daresay that' your businesses...your whole life may
suffer severe consequences. .
As a beginning to your decision making process, I- strongly
urge you to inspect those facilities you are using or considering
for use, at least once/year. No responsibly operated TSC site of
which T an aware would refuse such a visit. £ny that would,
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ire el irrina tt?r; rror consideration.
'n inspecting the site, five critical, areas should be
addr ; rseri :
I. Ovvner s/Cpera tor s of the Site
The financial status and capabilities should be
exairined. Central Motors would not have had to
pay ? 8./? rrillion to clean up Eerlin & Farro, if
Deri in & Farro had not gone bankrupt.
/'re the transporters and ether T5T facilities used
c" y the site in question capable, reputable, and
rel iar le?
Doe?, the facility have adequate insurance
coveraqe? Environmental Tirpairnent Liability
insurance is very difficult to obtain today, and
is very costly. Without adequate financial
capability, it is the only protection you have
frorr CFFCL^ costs.
TT. Tite Personnel
Is the* staff qual i f ied .. . exper ienced?
Do training programs exist to assure continuance
of qualified people operating the site?
r-'ow are documents and records managed? Poorly
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raintained recceds nay indicate a poorly-run
faci1ity.
ITT. Fite Situation
Ts the facility located in a residential area,
subject to the inherent risks and complaints?
Ts the site located where potential spills (ray
endanger nearby well water? Vvhat types of wastes
were handler1 that iray pose ultimate risk? Your
liabilities do not end/begin at the point in time
at which you ccrrn:ence business. The liabilities
are potentially al1-inclu?ive.
TV. Fegulatory Coirplianco Status
Are the necessary permits held? Any doubts can be
resolved by the appropriate regulatory agencies.
Copies of the pern.its should be examined.
Vihat is the compliance history of the site? A
concent order or other sign of difficulty does not
necessarily rule out consideration as any place
rrore than eight years old probably has past
practices to correct, but compliance monitoring in
such cases should be examined.
V. Operations
Co health and safety practices appear adequate?
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TP ec u i p mp n t jropcrly maintained?
.Is there secondary, and preferably tertiary
contai nment-. of solvent storaqe and handling areas?
Ts there a spill control plan?
,Ts there a contingency plan?
,Are there adequate warning and security signs?
.Are there internal inspection procedures? Are
they documented? All of these are required of a
properly run facility.
.Finally, how are the unrecoverable residues
handled? Some residues are suitable for cheir.ical-
based fuels programs, such as in cement kilns.
But what happens to those residues not sent for
fuel? Those materials should be sent to an
approved, permitted, commercial incinerator.
Tn edcition, every recycler is burdened with a water
disposal problen . P'ost incorring wastes have associated water
contamination to be removed. Also, water is the most corr.rronly
used medium to clean out process equipment to prevent cross-
contamination. Ke send these waters to TuPont in New Jersey for
biological and chemical treatnert, with the resulting effluent
being not only non-hazardous, but meeting drinking water
standards. These practices assure that the portion of waste
brought in that is not recovered as quality product, is destroyed
so as not to coire back to haunt us or our customers.
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If these five critical areas of concern have been adequately
add r essf IA, you rev rest assurer that you have done your task
properly, and selected accordingly.
Tn closing, let ire say that w^ile recycling can be shown to
be an economical alternative to disposal, our options have deeper
significance. \-'e should also view recycling as a viable rceans to
conserve increasingly finite resources, and to preserve our
environment for our children and future generations. \\e consider
ourselves part of the solution, not part of the probleiv,.
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Making the Most of Bottoms and Residuals
From Oil Refining and Solvent Recycling
Steve Miller
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MAKING THE MOST OF BOTTOMS AND RESIDUALS
Steven F. Miller, Ph.D., P.E.
Dames fi Moore
Historically most oil rerefining and solvent recovery
processes have focused on recovery of supernatants and "tops"
or distillates and consigned the bottoms and residuals to dis-
posal. That approach often left the most valuable molecules in
the discarded fraction which typically went to landfill. The
land bans which began taking effect in November 1986 were
expected to increase solvent recycling. Instead they appear to
have reduced solvent recycling. This is because solvent
recyclers who had generally discarded their bottoms to landfill
have now discovered better economies in RCRA fuel blending
programs than in recovery of tops plus incineration of bottoms.
The exceptions would include those few companies which had
captive incineration capacity.
Actually, hallogenated solvents continued to be recycled
but disposal of the bottoms from the hallogenated solvent
distillation via RCRA fuels programs required use of unrecovered
nonhallogenated waste solvents as dilluents to achieve maximum
chloride, solids and viscosity requirements. Thus recovery of
the nonhallogenated solvents was drastically curtailed.
I am going to tell you about a successful waste minimiz-
ation program by an oil and solvent recycling company which
focused on the use and reuse of its bottom streams, making
possible vitually total recycle of an increasing number of
hazardous waste streams. The benefit of total recycle is, of
course, reduced cost and reduced liability. The key to the
program was to persistently look for ways to recycle the parts
of the streams which would otherwise become disposal problems.
Of particular interest here are distillation bottoms and resid-
uals. What we will be discussing is not restricted technology
and similar approaches can be taken by other facilities if they
choose.
The Ekotek Experience
Ekotek was originally a marketer of lubricating oils which
decided to produce its own lubricating oils. The company
started collecting, rerefining and reselling used lubricating
oils in the early 1950's. Ekotek elected to rerefine its oil by
the Acid-Clay process which was popular at the time because it
produced a very high quality finished product. Automotive
lubrication requirements were relatively simple in the 1950's
and the used motor oils contained few additives, thus the acid
process was relatively easy to operate. During the 1960's, 70's
and 80's lube oil additive requirements increased significantly
which made the acid process more difficult to operate and
increased the quantity of waste produced.
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2 -
The acid process, as depicted in Slide 1, consisted of
dehydration or heating of the waste oil to -e»ove water and
a light fuel fraction and to crack the dipe sant part of the
additive packages in the oil. Then the oil was cooled and
treated with strong acid, typically of 98% H_SO. (sulfuric
acid), which sulfated and precipitated most components which
weren't stable lube oil molecules. Fifteen to twenty percent
of the liquid was drawn off the bottom as a heavy, tarry "acid
sludge" waste. This obnoxious waste which was high in lead and
sulfuric acid , which tended to escape as SO_ vapor, was
neutralized with limestone (CaCO ) prior to landfill
disposal. Many plants in the U.S. simply disposed of the acid
sludge in landfills without neutralization. Growing
environmental pressures in reaction to these disposal practices
caused many plants to close down.
Following this acid treatment step, the supernatent lube
oil fraction was again heated, this time in the presence of an
activated clay to remove color bodies. The spent clay was then
separated by filtration and disposed of in landfills.
The water removed from the process was treated by a
lime/alum in a reader/clarifier, with the treated water sent to
the POTW, and the resulting lime/alum sludge sent to landfill.
All three landfilled materials presented potential longterm
environmental liabilities. Attempts were made to recycle the
acid sludge by burning it at a sulfuric acid production plant
which normally produced H_SO by burning sulfur. Since the
material was approximately 30% sulfate and 70% burnable organic
compounds, this appeared attractive to company which owned the
acid plant. However, in Ekotek's case, that approach involved
shipping the acid sludge about 1000 miles in a bulk truck which
was expensive and risked occasionally having great difficulty
emptying the truck. In addition, the heavy metal loading from
the acid sludge was a burden on the acid plant offgas scrubbing
system. Actually, today we would be able to overcome these
difficulties, but that is another story.
In 1982 a distillation/clay process, depicted in Slide 2,
was developed and modeled to eliminate the acid sludge waste
product. Variations of distillation processes have become the
most common waste oil rerefining processes today. In place of
the acid sludge waste, a viscous, high flash (typically 550
F) bottoms product is produced which is useful as an asphalt oil
"cut-back" or viscosity reducing agent. Initially Ekotek's
bottoms product, which it called "asphalt flux" went to Phillips
Petroleum for cutting back road asphalt at about the price of
the road asphalt itself. Later, Ekotek's concern over the legal
definition of "putting bottoms on the ground" resulted in
selling all Ekotek asphalt flux to refineries to cutback roofing
asphalt prior to air blowing the asphalt to achieve final
product qualities.
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Here it was noted that the "impurities" present in the used
otor oils such as the polymer additives used to provide
ultigrade viscousity (e.g. 10W30, 15N40) contributed to final
roofing product quality and that the metals from additives and
from use (e.g. zinc and lead) catalyzed the air-blowing process,
thus increasing refinery thruput. Ekotek's arrangement with its
main new refinery customer became a profitable gallon-for-galIon
trade of one gallon of asphalt flux for one gallon of virgin
lubricating oil also produced by that same customer.
The lime/alum waste water process was replaced by polymer
addition. Combinations of polymer types were used. Both that
which separated by rising ("oil") and that which settled
("sludge") were recycled to the asphalt flux tower along with
the incoming used oil.
That left only the spent clay waste, containing oil and
color bodies but no significant metals, going as a "nonhazardous
industrial waste" to landfill. Ekotek considered hydrotreating
the oil as a substitute for the clay finishing step, as this
would have eliminated potential future landfill liability, and
improved both yield and product quality, but the capital cost
exceeded what Ekotek could afford. Ekotek therefore contracted
with a plant which burned coal and shale to make light weight
aggregate for cinderblock. The plant burned the spent clay
(which was approximately 30% lube oil and carbon) in place of
coal. The 70% clay "ash" was incorporated in the cinderblock
product. This proved beneficial to both parties and thus the
last potential landfill liability was resolved.
Now, as we examined what we had achieved via waste minimi-
zation we made other observations. Along with waste oil we had
been picking up caustic cleaning wastes from the local drum re-
conditioners and processing those wastes along with the ordinary
used oil. This stream was rich in paint polymer stripped from
the drum outsides by the caustic cleaning process. Our bench
tests indicated that this waste stream had only positive effects
on the asphalt flux product which was itself already rich in
polymers as well as on the ductibility of the final roofing
product. He therefore sought out other drum conditioners as
suppliers. These drum conditioners were delighted to have an
alternative to California landfills. He also expanded our
search for other polymeric bearing feedstocks which could be
made compatible with the asphalt flux.
At this point, Ekotek's RCRA history is worth mentioning.
Ekotek had originally received Part A status as a generator and
treator of acid sludge, a characteristic waste. Because used
oil is typically potentially contaminated by a variety of listed
solvents.
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Ekotek expanded its Part A to include receiving and processing
of such oil. Later it further expanded the Part A to include
permission to receive listed solvents for recycle or burning for
energy recovery in its industrial process heaters. It also
received approval for caustic and acidic wastes which it used in
the processes. It submitted for Part B status in July 1983 and
received the first Part B in Utah in July 1987. It also
successfully maintained environmental insurance.
Originally Ekotek had taken measures to minimize solvents
in its feedstocks, recognizing that the contaminated distillates
would make less desirable fuels. Later, with the oil
distillation process operating well, the company began to
examine individual solvent waste streams for their compatibility
with the new process. Solvent wastes typically contain
concentrated dissolved and suspended components and contaminants
accumulated in the solvent during use on its way to becoming a
waste. These components vary with the application but can
include a range of polymers, resins, dirt, oils and greases,
etc. The following approach became apparent:
A polymer bearing solvent waste could be added to previous-
ly conditioned asphalt flux (550 F flash point, prestripped
of all light volatile matter) as depicted in Slide 3, the
solvent stripped overhead through a distillation system and the
polymer retained in the flux. The extreme temperatures assured
no significantly measurable solvent would remain in the bottoms
product which was then equal or superior to the original flux
product.
Not all solvent wastes are compatible with the flux, so
bench testing of candidate stream was the key to success. In
addition, it was hard to model the high temperature operation at
the benchat first, and so initially several streams were
rejected which we were later able to make compatible.
Recycling waste printing inks became a major activity at
Ekotek. Most oil based printing inks recycled directly as if
they were used motor oil. The solvent based ink systems were
more difficult but the majority were compatible with the asphalt
flux product.
Degreasing solvents containing oil and grease (and a
relatively small quantity of dirt) were also flux compatible.
Similarly, drycleahing perc bottoms, rich in oils, were also
compatible. So were certain methylene chloride stripped paints
and a surprising vaiety of other waste streams.
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I believe that the examples given here of utilization of
bottoms indicates a general direction which needs further
exploration towards the recovery of bottoms in valued product
stream. If you have such stream in your plant or are a
recycling facility I encourage you to persist in finding hope
for your "liabilities" in a saleable product stream. This is
often not east but more possible than most people realize.
Since I left Ekotek and joined Dames fi Moore's San
Francisco office we have successfully applied similar
philosophies to develop hazardous waste pit cleanup and
hazardous waste management alternatives, including cleanup of a
number of pits previously thought to be non-recyclable. I am
extremely optimistic about future developments.
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Session IV
Treatment
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Treatment - Solvent Wastestreams
Robert H. Salvesen
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ABSTRACT
Treatment of used solvents is an option often selected as a
means of waste minimization or source reduction.
While the preferred treatment is recycling for the original use,
other technologies are available which enable solvents to be
used for other purposes.
This paper discusses the general types of solvents (excluding
halogenated materials) utilized by industry and commercially
available treatment technologies.
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INTRODUCTION
Solvents are used in many industries, mainly for cleaning and as
reaction media. Due to their generally high initial cost and
recent mandates to minimize waste generation and disposal, it is
prudent to consider how to maximize their recycle and reuse. A
separate paper on recycle and reuse has been prepared for
presentation at this symposium.
This paper will discuss solvent treatment technologies
(excluding recycle), which can provide reuse and disposal
options. The major topics to be covered are:
o Description of solvents used by various industries
Metal Cleaning
Paints, Coatings, Inks
Process
Adhesives
o Commercially available treatment technologies
Downgrading/Waste Exchange
Fuel use in Boilers, Cement & Asphalt Kilns
Stripping
Incineration
- Biodegradation
Oxidation
Encapsulation
Examples of all the above will also be provided.
Description of Solvents used by Various Industries
This section will cover the major solvents used in industry, but
is not intended as an all-inclusive discussion.
Metal Cleaning
Hydrocarbons, halogenated, oxygenated and mixtures of these
solvents are used for cleaning of metals containing carbon,
oils, grease, dirt, etc., and for paint stripping. Except for
the halogenated materials, these solvents are described briefly
below:
o Hydrocarbons
Mineral spirits, naphthas, toluene and xylene are the most
common types.
o Oxygenated
Ketones (MEK, MIBK), esters (ethyl or butyl acetate),
alcohols (methyl, ethyl, isopropyl), glycol ethers
(ethylene glycol), phenols and cresols are the major
types used.
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Mixtures - Ixtures of the above materials as well as
chlorinated olvents are used mainly for tough cleaning
requirements and paint stripping. Proprietary solvents
often contain special additives such as emulsifiers,
lanolin, colorants and odorants.
o Paint, Coatings and Ink
Paint, coating and ink industries, mainly utilize
hydrocarbons and oxygenated solvents as vehicles and
solvents. The latter are also widely used for cleanup
operations.
o Process
A wide variety of processes utilize a broad range of
solvents as reaction media, for finishing and cleanup
operations. Several examples follow:
Chemical reactions are often carried out in the presence
of sovents such as toluene, xylene, MEK, etc. These
solvents are also used to clean up equipment. Many
processes already include solvent recycle.
In the manufacture of Pharmaceuticals, for example,
drugs encapsulated in gelatin often require a finishing
step such as washing with a high-purity hydrocarbon
solvent.
Decaffination of coffee includes an extraction using
high-purity hexane or heptane. These solvents are
recycled.
o Adhesives
For the manufacture and application of adhesives, solvents
are essential. Hydrocarbons as well as oxygenated solvents
are used. Generally low boiling, volatile solvents are
desired.
Commercially Available Treatment Technololgies
o Downgrading/Waste Exchange
Downgrading is the term applied when a contaminated
solvent is utilized for another purpose within a plant.
Waste exchange is the term used when a used solvent is sold
or exchanged for credit or another material in another plant
or industry. There are a number of community, industry,
environmental and government agencies operating waste
exchanges.
Both activities involve used solvent which can be employed
in another operation with little or no treatment. Several
examples follow.
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- Precision bearings need very high-purity solvents
for cleaning. The solvent acquires very little
contaminant in usage and can be downgraded or
exchanged for other less demanding cleaning
operations.
- A special grade of mineral spirits is often used
as a calibrating fluid for pumps, fuel nozzles,
meters, etc. This material can readily be
downgraded or exchanged for cleaning purposes.
The military and other industries utilize large
volumes of this type of calibrating fluid.
o Fuel Use
Boilers in industry, operating on any types of
fuel, can be adapted to burn waste solvents,
provided certain requirements are satisfied.
Generally, boiler fuels require a minimum flash
point of about 135 F. Thus, only a few solvents
such as high flash mineral spirits (minimum flash
point of 140 F) are suitable. The only treatment
required is to blend the used solvent with what-
ever existing liquid fuel is employed. If gas or
solid fuels are normally burned, a separate fuel
handling system and appropriate burners would be
required.
o Cement Kilns
Cement kilns consume a lot of fuel and operate at
sufficiently high temperatures (about 2100 C/3844 F) to
decompose most organic compounds including halogenated
solvents. Studies by EPA have indicated that wet
.kiln operators throughout the U. S. and Canada have
successfully burned many types of organic wastes. Costs
for disposal by this method may range from $0.10-0.50/gal,
but this is usually much less than alternate treatment or
disposal options.
o Asphalt Kilns - Almost any low-cost liquid material can be
burned in asphalt kilns as fuel. However, since the
ingredients are not alkaline like cement, these kilns are not
capable of handling halogentated solvents.
o Stripping
For example, mixtures of organic solvents and oils can
be treated by stripping off the solvent in order to
recover both fractions for use as fuels or other purposes.
Several examples follow:
Hydraulic systems are often cleaned out with solvents
such as chlorinated or freon solvents. By steam
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stripping the solvent from the oil, the solvent can
be reclaimed and the oil burned as a fuel.
Used anti-freeze is stripped of water and the remain-
ing ethylene glycol burned as a fuel.
Soils and other solids contaminated with volatile
solvents can often be stripped by passage of air thru
these media. Depending upon the concentrations of
solvents in the air, the exhaust stream may be vented,
incinerated, or passed through an absorbent such as
activated carbon. The solvent can be regenerated from
the latter by steam stripping.
o Incineration
Treatment and disposal of used solvents by incineration
is often a last resort for low flash and mixed solvents.
Except for incineration by cement or asphalt kilns as
noted above, this method is generally quite costly due
to high operating and emission control costs. The major
types of incinerators (along with brief comments on each)
are discussed below.
Vortex - This is a relatively simple unit and occupies
little area for the throughput achieved. A high-
velocity air jet atomizes the feed and causes a spiral-
flame effect. This flame insures a long residence
time which generally assures fairly high combustion
efficiency. Most operating problems are due to re-
fractory failure due to inadequate temperature control
caused by variations in feed quality or slagging.
Erosion through impingment of materials on the internals
is also a major problem. Incineration of halogenated
materials requires efficient gas treatment.
- Rotary Hearth - This type of unit is a slowly rotating,
refractory-lined chamber. The design is similar to a
Vortex incinerator except that it is horizontal and
rotates. The advantage over a Vortex incinerator is
that the Rotary hearth can handle solids. Similar
problems with linings occur.
- Rotary Kiln - This type unit can handle a wide variety
of liquid and solid wastes. Many units have an after-
burner if the outlet temperature from the main chamber
is expected to fall below 800 C. Refractory linings
and mechanical stresses are the major operating problems.
Multiple Hearth - This is a vertical type unit with
grates through which the wastes move from top to bottom
and burn in successive stages. Liquid and semi-solid
wastes may be burned. Rotating arms or tines move the
wastes around. In the upper stages, rising hot
combustion gases dry the incoming materials. Lining
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materials and mechanical stresses are the major problems
in operation.
Fluidized Bed - In this type unit, wastes to be burned
may be liquid, semi-solid or solid. The material is
mixed into a fluidized granular bed of special sand
(1-3 mm diameter) which is heated to combustion
temperatures. This method assures good mixing of the
wastes and hot gases to provide complete combustion.
Compressed, preheated air is the fluidizing agent.
The fluidizing bed may contain special absorbents,
i.e., limestone, to react with combustion gases such
as HC1, S02, etc., to reduce or eliminate effluent
treatment requirements. Generally, cyclones are
required to remove entrained solids from the off-
gases. This type of unit is very flexible, but does
have problems with linings, slagging in the fluidizer,
and others depending upon the design and materials
combusted.
Circulating Bed - This type unit is an alternate to
fluid bed combustors and reportedly operates at higher
velocites with fine sorbents to obtain a more compact
unit that is easier to feed. Such units operate at
high combustion efficiencies and produce lower
emissions using less sorbent materials. Generally,
no off-gas scrubber is required and heat recovery can
be achieved to produce steam, electricity, hot water,
or hot air. This unit is very flexible and can burn
gaseous, liquid, slurry and solid wastes, but has
problems similar to those noted above for fluid bed
combusters.
Fume - These systems are used to burn off vapors prior
to emission to the atmosphere where recovery is not
desired. Incineration facilities work best on air
streams which contain solvents at 25% of their lower
explosive limit (l.e.l.). The minimum acceptable
concentration is 15% of l.e.l. (For a typical solvent
stream with a 1% l.e.l., this amounts to a 1500-2500 ppm
concentration.) At 25% l.e.l., such equipment can
provide a high calorific credit for the solvent burned.
Incinerators are not efficient at low concentration
effluents from, for example, a spray booth. Facilities
such as paint or coating bake ovens, where solvent vapor
concentrations are high, could profitably utilize fume
incinerators.
o Biodegredation
Biodegradation of organic materials is a natural process
that has been practiced on a broad range of substances.
Bacteria and microorganisms to decompose almost anything,
can be found in nature. Most organisms are ubiquitous, but
for commercial use in treatment and disposal of used wastes
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such as solvents, it is necessary to define the rates of
decomposition of the specific wastes and how to maximize
their rate of degradation in the desired environment.
Extensive studies on petroleum products have shown both
land-t sed and water-borne organizms can biodegrade these
materials in as little as 1-6 months. The decomposition
products are humic acids which generally are beneficial to
most soils.
This treatment method has potential for the following
solvents:
Aliphatic Hydrocarbons
Ethers
Alec Is
Glyc 'Epoxides
Este
Benze.
Phenol-
It must be noted that biodegradation is not a panacea
for all types of solvents or other wastes. However, the
potential for this method has not been fully utilized
and needs extensive testing to define acceptable con-
ditions for various substances.
o Oxidation
Oxidation by material organisms, air, ozone, and other
oxidizing agents, is commonly used for treatment of
many sustances. In recent years, claims have been
made for accelerating biodegradation of organics such
as solvents by addition of peroxides, or other oxidizing
agents.
o Encapsulation
An optional means of land disposal of wastes such as
paint sludges containing paint thinners, is by means of
encapsulation. Agents such as fly ash, silica gel,
epoxy resins, glass and other vitreous materials can be
used for encapsulation. While these treatment methods
are mainly used for sludges, some such materials can
contain solvents. Caution should be used in encapsulat-
ing these materiasls since the solvents may become mobile
over a period of time.
CONCLUSIONS
Used solvents from most industrial operations can be treated for
recycle, reuse or disposal. Recycle normally involves practices
such as segregation and redistillation to produce solvents
meeting new product specifications. Other treatment methods
such as blending for fuels, stripping, incineration,
biodegradation, oxidation and encapsulation are viable options
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for handling almost any type of used solvent. Commercial
experience has proven the benefits of these treatment
technologies.
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Treatment - Aqueous Wastestreams
David Pepson
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TREATMENT OF SPENT SOLVENT WASTEWATERS
- FOCUS ON CHANGING ECONOMICS -
David Pepson
Versar, Inc.
I. INTRODUCTION
Treatment technologies that are commonly used to treat spent solvent
wastewaters are steam stripping, carbon adsorption, and biological
treatment. These technologies have also been determined by EPA to
represent Best Demonstrated Available Technology (BOAT) for wastewaters
containing any of the 25 spent solvents that are defined under the
hazardous waste listings of F001 through F005. All of these technologies
are demonstrated and there exists a considerable amount of information on
the waste characteristics that affect performance and therefore need to
be evaluated regarding technology selection and use. One area of
treatment design that has not been examined to any great extent, however,
is whether past cost optimization studies are still valid in view of
changes in treatment requirements associated with the land disposal
regulations and other regulations (LDR) under the Hazardous and Solid
Waste Amendments of 1986.
The principal purpose of this paper is to examine some of the new
cost elements associated with each of the technologies mentioned
previously, as well as, to provide some "food for thought" in designing
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new/modifying existing treatment systems. This presentation, while
providing some information on the operation and applications of these
technologies, will focus on the changing economics of wastewater
treatment and associated changes in the selection and sizing of these
technologies. Following a discussion of each of these technologies, I
have performed an example optimization analysis which shows the impact of
the land disposal restrictions rule on treatment economics.
II. STEAM STRIPPING
Description
Because the term steam stripping is often used interchangeably with
batch distillation, an important first step in describing the operation
and application of this technology is to define the term "steam
stripping." Steam stripping, as used here, and described in EPA's spent
solvent final rule of November 1986, refers to a type of distillation
technology that is used to treat wastewaters that contain low
concentrations of volatile organic compounds. It is distinguished in two
significant ways from the technology of "batch distillation" which uses
steam to "strip" volatile compounds. First, steam stripping is used for
low concentration wastestreams, roughly less than one percent spent
solvent content, compared to batch distillation which generally is used
for wastes containing 50 to 90 percent spent solvents. Secondly, the
primary purpose of steam stripping is to comply with wastewater treatment
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standards; although the organics removed can be recovered and, therefore,
somewhat offset treatment costs. For batch distillation, the primary
purpose is economic recovery of spent solvents.
Application
As many of you know, a stream stripping unit consists of a boiler, a
stripping section, a condenser, and a collection tank. The number of
equilibrium stages needed (either in the form of trays or packing) in the
stripping section depend on the particular waste to be treated.
In practice, steam stripping is used by a number of manufacturing
facilities including those that manufacture agricultural intermediates or
Pharmaceuticals, where solvents are used as carrier solvents. Some
commercial solvent recovery facilities use steam stripping where wastes
have significant concentrations of water. Facilities also use steam
stripping to treat residuals from solvent extraction recovery processes.
Steam stripping can be used to treat most of the F001-F005 spent'
solvent compounds. It should be pointed out that EPA based BOAT on steam
stripping for only 12 of the 25 spent solvents; however, the rulemaking
record makes clear that for many of the compounds treatment data were not
available for steam stripping. Regardless, steam stripping can be used,
provided the standards are achieved. Waste parameters that affect the
selection of steam stripping are filterable solids, oil and grease, total
organic carbon, and other hazardous constituents that are minimally
volatile.
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Selection and Optimization Considerations
For facilities that plan to use, or are using, steam stripping as a
treatment technology, there are a number of design and operating factors
that should be re-examined in light of the LDR and other regulations
under HSWA.
First, and foremost, facilities need to examine the size of the steam
stripper. Prior to the land disposal rule, many facilities would size
steam strippers for 90-95 percent removal and then use carbon as a
polishing step. Under EPA's "derived from" rules, the spent carbon is
also a hazardous waste that will now require treatment prior to land
disposal. As a consequence of the treatment costs associated with the
spent carbon, it may now be more cost effective to increase the size of
the steam stripper and either eliminate the carbon system or
significantly reduce the pollutant loading on the carbon system so that
disposal costs are significantly reduced.
Another aspect to consider in the design of steam strippers is the
type of trays. Some trays provide better contact and, therefore,
increased efficiency, but may be more difficult to clean and, as a
consequence, generate larger quantities of material to dispose. Again,
under EPA's "derived form" rule, the cleaning waste is also hazardous.
Along this same line, facilities may also want to consider pretreatment
with polishing filters to reduce fouling and associated cleaning costs.
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EPA has also proposed regulations which govern air emissions from
stream strippers (as part of the Hazardous and Solid Waste Amendments of
1984, Section 3004). As a consequence, facilities still in the planning
stages should investigate various optimization scenarios for the stripper
condenser. For example, comparing the costs of chilled water versus the
use of carbon adsorption downstream from the condenser. Another
possibility is a larger condenser instead of add-on carbon adsorption to
remove hazardous organic compounds. It would also be prudent to consider
how you could modify the system if regulations were to become more
stringent. Given the fact that many areas of the country are looking to
further reduce VOC air emissions, facilities may want to build systems
that can easily be modified. For example, you may want to pipe the
system such that a second condenser could be easily retrofitted.
A final point regarding the use of steam stripping is that many of
the facilities that use this technology will discharge the streams to
POTWs or surface waters covered by a NPDES permit. As you probably know,
these discharges would not be subject to land disposal restrictions, but
rather the appropriate federal, state, and local regulations.
III. CARBON ADSORPTION
Description
Carbon adsorption can be used to treat spent solvent wastewaters by
adsorbing the organic compounds onto specially prepared carbon granules.
As many of you know, activated carbon is derived from virtually any
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carbonaceous material including wood, coal, coke, and petroleum
residues. The treatment system, itself, is quite simple consisting of a
packed column in which the wastewater generally enters from the top and
discharges after the distribution plate. This plate serves to minimize
the potential for channeling in the carbon bed.
It is important to note that carbon can be purchased with a range of
properties depending on the particular needs. These properties include
surface area, pore size, particle size, hardness, and iodine numbers.
The latter characteristic refers to a bench scale test where the amount
of iodine adsorbed is measured and used as an indicator of adsorption for
low molecular weight organics.
Application
Carbon adsorption can be used for a wide range of F001-F005 spent
solvent wastewaters. EPA determined that carbon adsorption, alone or in
combination with other technologies, represents BOAT for 8 of the 25
F001-F005 compounds. The waste parameters that should be considered in
selecting this technology are type and concentration of organic
compounds, filterable solids content, oil and grease, and the type and
concentration of various metals present in the waste.
Selection and Optimization Considerations
An important consideration regarding whether to use carbon adsorption
is the regeneration and/or disposal of the carbon. As noted earlier, the
spent carbon is considered a hazardous waste under EPA's "derived from"
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rule and facilities would therefore need to comply with RCRA provisions
and incur associated costs for storing, transporting, and disposing of
this material.
As a result, an important new consideration in optimizing the size of
the beds is the number of times that the spent carbon has to be
transported. It might be advantageous to increase the size of the beds
in order to minimize the number of times that the spent carbon has to be
transported as a hazardous waste. Of course, these costs would need to
be compared with other offsetting costs including higher pumping costs
associated with the greater pressure drop across the larger bed.
Another factor that plays an important role in cost optimization is
the type of carbon selected. It may be possible to use a carbon that is
more expensive initially, but can be used for longer periods of time
before regeneration.
IV. BIOLOGICAL TREATMENT
Description
Biological treatment involves the use of naturally occurring,
acclimated, or generically altered microorganisms to degrade organic
contaminants in the wastewater. Aerobic treatment is the most common,
wherein organic constituents are converted by microorganisms to carbon
dioxide, water, and cell protein. In the absence of oxygen (known as
anaerobic treatment), wastes are converted to methane and carbon monoxide.
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V. COST OPTIMIZATION EXAMPLE
Below is a cost optimization example that compares treatment costs
for two systems prior to and after implementation of the land disposal
requirements. While this example uses a number of simplfying
assumptions, it, nevertheless, provides a good illustration of the
potential impact that the land disposal rules can have on treatment
costs. The particular wastestream being evaluated is one that contains
500 mg/1 of methylene chloride and trace amounts of other constituents
including filterable solids and oil and grease. The technologies being
compared are stream stripping (10 tray column) in combination with carbon
adsorption and steam stripping alone, but with 50 equilbrium stages. The
cost analysis has been simplified and includes only capital costs for the
various technologies and annual costs associated with disposal of the
spent carbon. An actual cost analysis would be much more complex,
including such annual costs as regeneration of carbon prior to the need
for disposal (remember also, that any wastewater generated as part of
regenerating the carbon is also hazardous), disposal costs for
non-reuseable material from steam stripping, and costs for air emission
controls on the steam stripper. It is important to point out that many
of these annual costs have been considered in past optimization studies.
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Application
Biological treatment can be used for most of the F001-F005 spent
solvents. EPA has determined that this technology, alone or in
combination with steam stripping or biological treatment, represents best
demonstrated available technology for 9 of the 25 F001-F005 spent
solvents. Waste parameters that affect the selection of this technology
include filterable solids, oil and grease, the presence of toxic metals,
surfactants, and the presence of refractory organic compounds.
Selection and Optimization Considerations
Biological treatment can result in the generation of solid residuals
that would be classified as hazardous under EPA's "derived from" rule.
Accordingly, facilities that plan to use this technology need to evaluate
costs associated with storage, transport, and disposal of these hazardous
residuals. Facilities may also want to take a closer look at
technologies that have been developed more recently, such as wet air
oxidation to replace or enhance biological treatment. Wet air oxidation
would likely be more energy intensive than biological treatment, for
example, but the fact that less residual material is generated may result
in an overall savings. Additionally, biological treatment of certain
compounds can result in air emissions which the Agency is currently
studying with respect to the need for regulation. A final point with
regard to the use of biological treatment is the fact that it may be
possible to delist the treated residuals. If this is the case, then the
economics would not significantly change.
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In this example, the facility needs to reduce the concentration of
methylene chloride from 500 mg/1 to 0.5 mg/1 in order to comply with
federal wastewater treatment requirements. It is assumed that the
10 tray column can reduce the methylene chloride content by 99% to 5 ppm
and that addition of the carbon system will achieve the 0.5 mg/1
standard. -It is also assumed a the 50 tray steam stripper can achieve a
reduction of 99.9 percent and, therefore, achieve the treatment standard
alone without the need for carbon adsorption. Prior to the LDR, one
could assume minimal costs for land disposal; however, today the treater
must include treatment costs for incineration at an approved incinerator
prior to land disposal of the spent carbon. The analysis assumes that
the carbon is regenerated once every seven days, and after the fifth
regeneration cycle it is no longer useful and must be disposed as a
hazardous waste. Disposal costs are S300/drum and transportation costs
are $500 per trip.
As shown in Table 1 below, the inclusion of treatment costs due to
the LDRs reverses the treatment selection picture. Without these costs,
the combination system (i.e., steam stripper plus carbon adsorption) is
$76,000 less than the 50 tray steam stripper; with these increased
treatment and disposal costs converted to capital dollars, the steam
stripper is $212,000 less expensive than the combination system based on
a present-worth analysis.
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Table 1.
Cost Optimization Summary
Case I Case II
Steam stripping
(10 trays)
+ $224,000 $512,000
Carbon adsorption
Steam stripping $300,000 $300,000
(50 trays)
Case I: Assumes minimal cost for disposal of spent carbon
Case II: Includes cost for incineration of spent carbon
prior to land disposal
VI. CONCLUSIONS
Effective treatment of spent solvent wastewaters can be accomplished
with a variety of individual technologies or technology trains. With the
promulgation of the land disposal restriction rules and other regulations
being developed under the Hazardous and Solid Waste Amendments of 1986,
facilities may want to re-examine the economics of the wastewater
treatment technologies either planned or now being used.
One important aspect of these recent regulations may well be that
past practices of including "polishing"^or "back/up" systems as part of
treatment trains is no longer cost effective. Under today's
requirements, facilities may find improved control systems to be a better
alternative. One possibility is continuous monitoring of the wastestream
and automatic diversion to holding tanks when the waste does not comply
with regulatory requirements.
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