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For more
information, contact David Eppstein by email at
deppstein@masco.harvard.edu,
or by calling 617-632-2860.
5.0 SOURCE REDUCTION CONCEPTS
Since
source reduction may be a significant part of the solution to a
sewer discharge compliance problem, it is important to
understand the concepts of source reduction. Source reduction is
defined in the federal Pollution Prevention Act of 1990 as:
...any practice which:
(i)
reduces the amount of any hazardous substance, pollutant, or
contaminant entering any wastestream or otherwise released
into the environment (including fugitive emissions) prior to
recycling, treatment, or disposal; and
(ii)
reduces the hazard to the public health and the environment
associated with the release of such substances, pollutants
or contaminants.2
In
source reduction, pollutants or contaminants are eliminated or
reduced within the process before they enter the wastestream.
Many people interchangeably use the terms source reduction,
pollution prevention, and waste minimization.
For an
industrial process, a source reduction "opportunity"
means any input of raw material, reagent, or energy; any loss or
waste of that input; or any generated byproduct or waste
material. A source reduction "option" means a possible
means to achieve the reduction of an opportunity.
The
first step in a source reduction program is to identify source
reduction opportunities. Then, a number of possible source
reduction options to address each identified opportunity should
be conceived (developed) and studied for implementation.
During
development of the options, source reduction literature can be
examined. The literature typically explores only a few options
for a given opportunity. Thus, companies should attempt to
identify source reduction options that suit their own
operational methods.
It is
generally accepted that all source reduction options can be
defined, in order of priority, as procedural changes, material
changes, technology changes, and recycling and reuse.3
5.1
Procedural Changes
This
category of source reduction options involves changes to
operating practices in a facility. The development of such
changes is sometimes called the development of "Best
Management Practices." Procedural change options are
usually given the highest priority because they involve no
capital expenditures and are often the easiest to implement.
Identification
of procedural change options requires a detailed study of
operational steps of the process under review. Company
procedures that would typically be studied for implementation of
source reduction include:
5.2
Material Changes
Source
reduction literature often limits this category of options to
finding a specific less toxic substitute for a current reagent
or compound. For example, aqueous cleaners are often examined as
substitutes for chlorinated or organic solvents.
Actually,
the material change option category can include material
purification and dilution4 as well as substitution.
Moreover, material change options can include product material
changes as well as input material changes. Product material
change methods include substitution, conservation, and change in
product composition.
For
cleaning operations, which often produce large amounts of wastes
and, therefore, can offer major source reduction opportunities,
there are three types of materials involved: substrate, dirt,
and solvent. All three of these materials can possibly be
changed in a source reduction effort. As an example, if the base
material of a product can be changed from metal to plastic, the
need for a surface cleaning step before a finish coating step
may be eliminated.
To
accomplish material changes, a facility would begin by
conducting a survey of all materials used in each area including
operating and maintenance materials. Then, material compositions
and contaminations would have to be identified. At this point,
studies would be done to learn how each product is used so that
possible elimination, replacement, or minimized use could be
evaluated.
For
mercury, material change options can be difficult to identify if
the effort is intended to reduce mercury concentrations in
process wastewater discharges below 1.0 µg/L (ppb). The major
reason for this difficulty is that contaminant concentrations in
the ppb range are usually considered "trace"
contaminations and information on trace contaminants of most
products and reagents is not readily available. For example,
Material Safety Data Sheets (MSDS) issued by suppliers of
products are required by law to list a chemical constituent only
if it constitutes at least 1 percent (or 10,000,000 µg/L (ppb))
of the product.
In
1995, the Operations Subcommittee of the MWRA/MASCO Mercury Work
Group compiled a list of hospital laboratory reagents and other
products in a database called the Mercury Products Database.
Approximately 5,500 chemicals were listed with actual mercury
data available for about 700 products. The database is being
updated in the Phase II Work Group activity. The updated
database will have mercury data for more than 800 products.
5.3
Technology Changes
This
category of options can involve changing the equipment used in
the process operation or using another technological approach to
achieve the same product or result. For example, a new,
efficient washing machine may be substituted for an old,
inefficient washing machine. In surface cleaning, mechanical
cleaning methods may be used instead of solvent cleaning. For
laboratory test equipment, a new analytical instrument may
require smaller sample sizes or may reduce or eliminate the use
of certain reagents.
Technology
change options can also include:
-
Process
changes
-
Equipment,
piping, or layout changes
-
Changes
to process operational settings
-
Additional
automation
-
Energy
conservation measures
-
Water
conservation measures
5.4
Recycle and Reuse
Although
this category of options may not be considered as source
reduction to the pollution prevention purist, recycle and reuse
options can reduce water usage and quantities of toxic materials
discharged to sewers or shipped from a facility for disposal.
Recycle
and reuse options can include:
-
Recycling
or reusing portions of a waste stream within the original
process.
-
Using
a waste stream as a raw material in a different process or
facility.
-
Treating
a waste stream to reclaim portions for recycle or reuse
within the original process or a different process or
facility.
Under
this category, separation technologies are often used on
wastewater streams to reuse the water or to remove constituents
of regulatory concern for recycling to the process as material
inputs. For example, formaldehyde-bearing waste streams can
sometimes be distilled to recover and reuse the formaldehyde.
5.5
Option Feasibility Analyses
Once
several possible source reduction options have been conceived
and initially explored, those holding promise of the greatest
waste minimization opportunities or cost savings would be
evaluated. For each selected option, the evaluation would
examine technical, environmental, and economic feasibility
issues.
Technical
feasibility analysis would attempt to decide if the option will
work in the particular process application being assessed. Key
considerations include product requirements, maintenance
requirements, space requirements, compatibility with existing
operations, and operator training and safety. Vendor
consultations or pilot-scale testing may be needed to complete
the analysis.
If a
proposed source reduction option passes the technical
feasibility analysis, it is necessary to evaluate its
environmental feasibility. An environmental feasibility analysis
would attempt to gauge effects of the option on all aspects of
environmental compliance including emissions to air and water,
generation of solid waste, possible judgments or fines, and
future liabilities.
Once a
proposed option passes the technical feasibility analysis and is
found to have a favorable environmental feasibility, it is
necessary to evaluate its economic feasibility. Profitability
indicators such as payback period, return on investment, and net
present worth can be used. The economic evaluation would usually
involve both capital and operating cost estimates.
Capital
cost estimating data may include equipment purchase costs, site
preparation costs, support material costs (such as foundations,
piping and instrumentation), installation costs, engineering
costs, startup and training costs, initial permit fees, and raw
material inventory costs. Operating cost data would generally be
calculated as incremental higher or lower costs from the current
situation. Operating cost categories may include annual permit
fees and reporting costs, waste disposal costs, raw material
costs, utility costs, insurance costs, operating and maintenance
costs, overhead costs, revenues from sale of byproducts, and
revenue from increased or decreased production.
The
measure of payback period is frequently calculated by source
reduction assessors because of its relative simplicity. An
example is the payback period analysis found in Appendix B
prepared for a printing facility regarding the option of
installing a fixer recirculation system in its photoprocessing
operation. Corporate financial officers often prefer to use the
economic measures of return on investment or present net worth
for making investment decisions. Additional discussion of
economic analyses can be found in Section 11.0 of this Manual.
5.6
Option Implementation
In the
implementation stage of a source reduction program, necessary
resources would be obtained, equipment would be installed,
procedural changes would be made, and performance would be
evaluated. Typically, a company would pursue implementation of
those options that are low in initial costs and offer a
combination of benefits including reductions in material uses
and environmental discharges, improvements in occupational
health and safety or in energy efficiency, and an overall
savings in plant operating costs.
Since
the idea of changing an existing process often meets with
resistance from departmental supervisors and staff, the source
reduction implementation stage might also involve considerable
managerial effort. Successful approaches have used policy
directives and delegations of authority by upper management to a
source reduction team drawn from all departments of a facility.
After
experiencing initial successes, the source reduction team has
credibility within the facility and may then go on to implement
more difficult or more costly options. This means that ways to
measure program effectiveness need to be in place. Waste
reduction is the ultimate goal and the key factor in measuring
effectiveness.
In
addition, employee training programs on process operations and
waste management have successfully been used during
implementation of source reduction programs and as a means to
assure continued benefits after implementation. While such
training programs should be tailored to meet specific needs at
each facility, the following topics should be considered:
-
regulatory
agencies
-
sewer
discharge regulations/prohibitions
-
plumbing
infrastructure information
-
pretreatment
systems information
-
source
reduction goals and techniques
-
mercury
source list
-
procedures
for purchasing mercury-containing materials
-
product
substitutions
-
material
handling techniques
-
wastewater
sampling protocols
-
wastewater
pH monitoring
-
waste
management procedures
-
recycling
opportunities
-
spill
prevention and containment
-
waste
disposal protocols
The
operations and waste management training programs should be
presented to all affected facility personnel. Ideally, newly
hired personnel should be trained within thirty days of hire.
All staff members should be retrained annually, at a minimum. In
addition, an audit program should be developed to learn if the
operations and waste management training programs are effective.
Periodic unannounced inspections should take place throughout
the year to detect staff compliance with the operations and
waste management policies of the facility.
To keep
personnel up-to-date on all waste management issues, facility
managers may want to develop newsletters, informational
postings, publish articles, or use other appropriate means of
communication with the staff. The key to a successful training
program is to keep employees informed of waste management
policies and to help them understand that individual actions can
make a substantial difference in the overall environmental
quality and impact of their workplace.
The
overall source reduction program cannot be a one-time effort but
should become an ongoing part of the overall manufacturing
process. The need for repeated source reduction assessments
becomes especially important when there are:
-
Changes
in raw materials or product requirements
-
Changes
in waste management costs
-
New
technologies become available
-
Changes
in regulations
-
Major
environmental events such as spills or accidental acute
employee exposure
A truly
successful source reduction program, therefore, is a continuing
process of assessment, implementation, measurement, and
reassessment. The success of source reduction may be measured by
reduced costs in production and environmental compliance
including pretreatment.
242 USC 13102.
3In
Massachusetts, the Toxics Use Reduction Act (MGL 21 I), enacted
in 1989, classified six types of toxics use reduction options:
input substitution, product reformulation, process redesign,
process modernization, improved operations and maintenance, and
in-process recycling and reuse. These six types of options
are covered by the four broader types of source reduction
options discussed in this Manual.
4Dilution is
used here in reference to a process stream. Dilution
of a wastewater stream to achieve a discharge limit is
prohibited by federal regulations (40 CFR 403.6(d)) and MWRA
regulations (360 CMR 10.025).
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