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| There are a number of environmental concerns related to the
disposal of metal removal fluids. But the first way to address these concerns is to reduce
the amount of MRF that must be disposed of. |
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| How can waste disposal be reduced? |
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| Recycling of fluid can be an
important part of waste reduction. It is necessary to consider the types of metal removal
fluids that are to be recovered/ recycled since different types require different action
plans. |
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| From an environmental standpoint, the two main groups of metal removal
fluids are water-dilutable fluids
(soluble oils, semi synthetics, and synthetics) and straight oil removal fluids. There are
different methods for extending the performance of these two main groups. |
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| It’s important to remember that reclaimed or recycled MRF straight
oils must be kept separate from other used or recycled oils in the shop. It is especially
important that used engine oil does not contaminate the MRF straight oils, since it may
contain cancer-causing contaminants from the combustion process in the engine. |
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| While waste disposal can be reduced, it cannot, of course, be completely
eliminated. |
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What are the environmental
issues related to metal removal fluids?
Environmental concerns can include the
following:
Why are there environmental concerns
about waste metal removal fluids?
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Spent metal removal fluids typically contain high levels of oil and grease and
dissolved (or soluble) organic compounds. Other oily wastes—such as soaps and
detergents from parts washing, machine lubricants, floor mop water, and rust
inhibitors—may also be present.
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Also, depending on the metal being machined, some level of dissolved and suspended
metals will be present in these spent solutions. The Federal EPA (Environmental Protection
Agency), State EPAs and local environmental control authorities regulate the disposal of
these compounds and metals. Improper disposal of these fluids can cause harm to
the environment, and can result in costly fines and other penalties.
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| Do the pollutant characteristics
vary in different metal removal fluid types? |
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| Yes. Among soluble oil, semi-synthetics and synthetics, the primary
difference is the oil and grease content of the fluid in use. The second characteristic
difference is the amount of soluble organic materials present in the working fluid. These
soluble organic materials are indirectly measured by tests such as the biochemical oxygen
demand – five-day (BOD5), chemical oxygen demand (COD), and total organic
carbon (TOC). |
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| As a result of the wide variations of wastes that can be presented to a
wastewater treatment system, six different metal removal fluid
types were tested across various technologies. This was done to give an
indication of relative performance. The results discussed in this section are not intended
to be reflective of all possible combinations of fluids, fluid types and mixtures. Each
method should be evaluated on actual spent metal removal solutions. |
What are my options for proper disposal of spent
metal removal fluids?
| There are several different methods for disposing of spent metal
removal fluids. Some of the more common methods are |
Click on any of the above links to find out about that particular kind
of MRF disposal.
Why should I choose one method over another?
While there are no hard and fast rules, the reasons for choosing one method over
another are:
 | cost |
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| quality of water after a wastewater treatment process |
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| complexity of the wastewater treatment process |
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| local site conditions, i.e. local pollutant restrictions |
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What requirements are there for
wastewater discharges to the sewer system?
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| Industrial wastewater discharges into navigable waters require a National
Pollution Discharge Elimination System (NPDES) discharge permit under the Clean Water Act
(CWA). Navigable waters are defined broadly; they can be anything from a ditch that
ultimately runs into a creek to rivers, streams, and oceans. In most states, the state
environmental agency has the authority to administer the federal Clean Water Act and issue
NPDES discharge permits. If the state does not have federal permitting authority, federal
permits are issued by the USEPA regional office. NPDES permit are issued for set time
periods not to exceed five years. |
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| Permit applications and renewal applications require detailed information
about the nature of the facility’s operations and a chemical analysis of the
discharge. Permits limit the amount of specific pollutants allowed to be in the discharge.
Mass limits are required. Concentration limits may also be included. In some circumstances
where the intake water is contaminated, the facility may qualify for an intake water
credit to offset the effect of the contaminated water. |
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| Limits are derived from several sources, including Effluent Guidelines for
Industrial Categories, State or Federal Water Quality Standards, and Best Professional
Judgement Limits. Some parameters typically limited in discharge permits include pH,
biological oxygen demand (BOD), chemical oxygen demand (COD), metals, oil and grease,
suspended solids, and temperature. Permits include standard provisions governing
monitoring and reporting, as well as a variety of other activities that are not directly
related to discharge limits. For example, permits may require testing the effluent’s
effect on aquatic organisms. |
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| Facilities that discharge industrial wastewater to publicly owned
treatment works (POTWs) fall under the permit requirements of the receiving POTW. The
conditions in this type of permit contain effluent limitations that the POTW can except
and still meet the provisions of their own NPDES permit. The permit conditions found in
pretreatment permits are similar to those found in NPDES permits, but with more lenient
limitations for conventional pollutants such as BOD, suspended solids, and oil, since the
discharged wastewater will receive additional treatment at the POTW. |
What permit requirements are there for emissions of MRF
particulate
matter?
| Air emissions from industrial sources are subject to strict legislation by
the Clean Air Act. The Clean Air Act imposes numerous complex and overlapping
requirements. To ensure compliance with air regulations, a facility must first identify
all potentially applicable requirements. To do this, it is necessary to inventory, by type
and quantity, all air emissions at the facility. This information will determine which
requirements are in fact applicable. |
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| Areas of the Clean Air Act impacting reporting and permit requirements for
MRF volatile organic compound and particulate matter emissions may include the following: |
| Reasonably Available Control Technology (RACT) Standards |
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| Prevention of Significant Deterioration (PSD) requirements |
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| Hazardous Air Pollution (HAP) requirements |
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| Maximum Achievable Control Technology (MACT) Standards |
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| New Source Performance Standards (NSPS) |
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| Operating Permit Requirements |
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| Significant record keeping, reporting, monitoring, testing, and sampling
requirements usually are imposed on affected facilities under all of these federal Clean
Air Act programs. |
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| The federal Clean Air Act is implemented through State Implementation
Plans (SIP), which individual states develop with U.S. Environmental Protection Agency
(EPA) oversight. In addition to federal requirements, SIPs often contain their own
independent permitting, reporting, record keeping, monitoring, testing, sampling, emission
control, and other requirements. Local governments also may impose certain requirements
relating to air emissions. Therefore, in order to develop a comprehensive compliance
program tailored to meet a specific facility’s needs, each facility must conduct its
own independent review of the potentially applicable requirements. This review must
include an examination of federal, state, and local laws and regulations. |
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Contact Chris Roman, 