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From: TSS (
Subject: EPA's CWD waste disposal recommendations (EPA Region 8)
Date: April 28, 2004 at 9:52 am PST

EPA Region 8
Recommended Best Management Practices for Disposal of
Laboratory Waste Potentially Contaminated with Chronic
Wasting Disease (CWD)
April 26, 2004


This document provides information and recommendations
about technologies and best management practices for
treatment and disposal of laboratory wastes that may be
contaminated with chronic wasting disease (CWD). It was
developed in collaboration with many interested stakeholders
and is a framework for decisions regarding CWD that may be
used by laboratories and by Federal, state, and local
agencies within Region 8. This paper does not create any
new regulations. The recommendations are not legally
binding requirements nor do they change or substitute for
any State, federal, or local statutory or regulatory
provision. Reasonable measures are recommended that should
help protect the environment while the science concerning
CWD develops further and more information becomes available.

CWD belongs to the transmissible spongiform encephalopathy
(TSE) family of diseases. CWD naturally affects mule deer
(Odocoileus hemionus), white-tailed deer (Odocoileus
virginianus), and Rocky Mountain elk (Cervus elaphus
nelsoni) in the United States and Canada (O’Rourke et al.
1999; Sigurdson et al. 1999). CWD has not been found to date
in humans (CDC 2003a) and other animal species are not known
to be naturally susceptible to CWD (Williams and Miller
2002). The fate and transport of the CWD agent in the
environment are poorly understood, although it may survive
in the environment for extended periods of time (Miller et
al. 2004; Brown and Gajdusek 1991; Palsson 1979). In
addition, it appears that CWD can be transmitted among deer
and elk either through direct contact or indirectly through
environmental contamination. (Miller et al. 2004; Williams
and Miller 2002; Miller et al. 1998)

Within EPA Region 8, CWD has been found in free ranging
deer and elk in Colorado, Wyoming, South Dakota, and Utah.
Animal testing laboratories are important in ensuring that
infected carcasses are identified so that the disease can be
accurately mapped by state and Federal agencies. To
minimize the potential for more widespread distribution and
re-circulation of CWD agents in the environment, EPA Region
8 recommends that laboratories implement reasonable,
protective best management practices (BMPs). EPA Region 8
recognizes and supports the need for the surveillance and
testing programs and related research. Our intent is to
help reduce environmental risks from potentially
CWD-contaminated wastes associated with laboratory testing
and thereby support the continuation and expansion of these
programs, as necessary. Potentially CWD-contaminated wastes
are waste materials derived from deer or elk from herds or
areas where CWD is known to occur.

Although the focus of this document is confined to CWD, EPA
Region 8 recognizes that other animal TSE agents (e.g.,
scrapie) may occur in animal wastes and tissues that are
handled by laboratories. Many of the same scientific
concerns and uncertainties associated with CWD-contaminated
wastes are relevant to waste that may be contaminated with
these other animal TSE agents. EPA and several other
Federal agencies are considering these scientific issues
through coordinated efforts.

EPA Responsibilities

Where existing laws administered by EPA apply to the
treatment or disposal of laboratory wastes that may be
contaminated with CWD, the Agency is responsible for
preventing environmental contamination associated with this
type of waste material. A general summary of laws that may
apply to treatment or disposal of potentially
CWD-contaminated laboratory wastes is presented below. In
some situations, our recommended best management practices
may be incorporated into permits or other enforceable

Under the Clean Water Act (CWA), the direct discharge of
pollutants to surface waters is prohibited except in
compliance with certain sections of the CWA, including
section 402. Under Section 402, EPA or an authorized state
may issue a discharge permit to Publicly Owned Treatment
Works (POTWs), which would require POTWs to implement and
enforce CWA pretreatment standards and requirements.
Pretreatment standards and requirements limit or prevent the
discharge of pollutants by non-domestic users that may pass
through the treatment works into the receiving waters,
preventing interference with POTW operations or sludge
disposal, making sure that worker health and safety are not
adversely affected, and ensuring that biosolids from the
POTW can be recycled or reclaimed.

Under the authority of the Safe Drinking Water Act (SDWA),
EPA’s Underground Injection Control (UIC) Program is
required to prevent endangerment of existing and future
underground sources of drinking water from any underground
injection activities that might adversely affect human
health and the environment. Shallow disposal systems that
discharge certain types of fluids into the subsurface are
known as Class V UIC wells. These disposal systems can
include septic systems receiving waste fluids or any other
conduit to the subsurface by which fluids are released to
ground water. EPA and states with authorized UIC programs
regulate injections into Class V wells and may require
permits for such injection.

The Resource Conservation and Recovery Act (RCRA)
establishes, among other things, requirements for disposal
of solid and hazardous wastes. All Region 8 states have
received program approval from EPA under RCRA, Subtitle D by
adopting required regulations for Municipal Solid Waste
Landfills. Therefore, the states are primarily responsible
for regulating landfills in Region 8. EPA provides advice,
as needed, to the states. In addition, RCRA section 7003
authorizes EPA to protect health and the environment against
potential endangerment stemming from the handling, disposal,
and other management of solid and hazardous waste.

The Clean Air Act (CAA) provides the authority to EPA and
delegated states to regulate sources of air pollution.
Criteria pollutants (e.g. particulate matter and carbon
monoxide), and hazardous air pollutants (HAPs) such as
dioxins, dibenzofurans, mercury, cadmium, and lead are
potential incinerator emissions regulated by the CAA and 40
CFR Part 50. The applicability of a given Federal and/or
state regulation to an incinerator depends on the type of
waste being burned. While EPA has authority to regulate
other sources of air pollution, only state regulations for
pathological waste incineration and other state-specific
requirements are applicable to potentially CWD-contaminated

Under the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA), any chemical that is intended to prevent,
destroy, repel, or mitigate any pest must either be
registered as a pesticide product or exempted prior to its
sale or distribution in the United States. The applicant
for registration or exemption is responsible for providing
the data necessary for EPA to determine that no unreasonable
adverse effects will occur from the product’s proposed use.

Treatment and Disposal Options

This section provides general information concerning waste
management options and technologies that EPA recommends for
treatment and disposal of potentially CWD-contaminated
materials. When the following options are being considered,
laboratories should consult with the appropriate Federal,
state, or local regulatory authorities for specific
requirements that may apply and for additional information.

Discharge to Sewage Treatment Plants (POTWs)

Since there is no method currently available to detect and
quantify concentrations of CWD agents in fluids or sludge,
EPA Region 8 recommends using best management practices
designed to minimize CWD agent release from POTWs into the
environment. However, minimal discharge of fluid waste with
low infectivity, such as blood and wash water generated from
a necropsy procedure, may occur. Laboratories that
discharge to a POTW will be covered by a pretreatment permit
issued by the POTW, which may contain these best management
practices as well as other requirements that are generally
applicable to laboratories. EPA intends to issue additional
guidelines for POTWs receiving laboratory wastes that will
be compatible with this document, after seeking comments
from POTWs, state pretreatment coordinators, laboratories,
and other affected parties.

Alkaline Hydrolysis

Alkaline hydrolysis is a potential treatment option before
discharging to a POTW or disposing of residues in a
landfill. Alkaline hydrolysis involves the use of a
concentrated alkaline solution (one molar sodium hydroxide
or potassium hydroxide) along with temperatures over 300o F
(149o C) and high pressures (approximately five bars) for a
period of six hours to ensure that tissues and proteins
(including CWD agents) are hydrolyzed or digested in a
vessel similar to a large stainless steel pressure cooker.

POTW discharge limits that may apply to alkaline hydrolysis
products include biochemical oxygen demand, solids, total
dissolved solids, pH, temperature, and chemical specific
pollutants. EPA Region 8 and the POTWs have not identified
any significant concentrations of toxic pollutants of
concern in the discharge to date. The end product of the
alkaline hydrolysis process may also be dehydrated and sent
to a municipal solid waste landfill.

Discharge to Septic Systems (UIC Class V Wells)

If a laboratory discharges fluid waste to a septic system,
UIC permit requirements for waste streams that potentially
include CWD may specify best management practices to
minimize the volume of CWD-contaminated wastes entering the
waste stream. Permit requirements should also include
practices for disposal of septic system sludge in a manner
that protects the environment, such as proper incineration,
alkaline hydrolysis, or disposal in a suitable municipal
solid waste landfill after the sludge has been dehydrated.
Laboratory materials discharged, such as inactivation
chemicals, must not adversely affect or destroy the septic


When a laboratory is considering landfilling as the disposal
option for potentially CWD-contaminated waste, it should
consult with the state in conjunction with the waste
management industry. The definition of infectious waste
varies among states, which could affect the standards
associated with collection, handling and disposal of waste
that can include tissue, body parts, heads, and carcasses of
CWD-affected animals and contaminated laboratory material.

The EPA Office of Solid Waste has recommended “Interim
Practices” to minimize the possibility of releasing the CWD
agent from landfills (EPA 2004b). Disposal of potentially
CWD-contaminated material in state-permitted municipal solid
waste landfills that are in full compliance with state and
federal environmental regulations and have no uncontrolled
releases from the receiving landfill disposal cell would
help reduce the potential for further spread of the disease.
Please refer to these “Interim Practices” for additional
information on landfilling.


Incineration is considered by experts to be an effective
method for disposal of CWD-contaminated wastes (WHO 1999).
Depending on state regulations, incinerator ash may be
disposed of in state-permitted municipal solid waste

High temperature incineration in a multi-chamber controlled
air system provides an opportunity for complete combustion
of the solid waste resulting in the mitigation of criteria
air pollutants and HAPs, as well as odor and smoke. The
Industrial Combustion Coordinated Rulemaking (ICCR) Federal
Advisory Committee, which advises EPA, recommends that good
combustion practices be adopted when burning pathological
waste, specifically a retention time of at least one second
in the secondary chamber and minimum secondary chamber
temperatures of 1,600o to 1,800o F (871o to 982o C). In
addition, the Committee recommends the use of combustion
temperature controls. Air pollution control technologies
such as gas scrubbers, fabric filters, and good combustion
practices have proven effective when used in conjunction
with pathological waste incineration (EPA 1994).

Cleaning Contaminated Surfaces

EPA recommends that appropriate chemical solutions be
applied to inactivate CWD agents that may remain on
contaminated, hard, nonporous surfaces (e.g., non-disposable
instruments, necropsy floor, tables, counters, sinks). There
are currently no EPA registered products approved for
inactivation of CWD agents from contaminated surfaces. EPA
has granted emergency exemptions under FIFRA to several
states in Region 8 allowing the use of a commercial aqueous
acid phenolic product, Environ LpH, for inactivation of the
CWD agent on contaminated, hard, nonporous surfaces.
Environ LpH must be used according to all relevant
conditions of use specified in the applicable emergency
exemption issued to each state (EPA 2004a). The Centers for
Disease Control and Prevention (CDC 2003b) and the World
Health Organization (WHO 1999) recommend sodium hydroxide
and sodium hypochlorite (bleach) for inactivating TSE agents
on surfaces. However, any chemicals with claims for
inactivation of the CWD agent would need to be granted a
registration or an emergency exemption under FIFRA prior to
sale and distribution in the U.S.

EPA recommends that procedures for inactivation of CWD
agents on contaminated, hard, nonporous surfaces be
completed before discharging wastewater to POTWs or septic
systems. Inactivation solutions should not be allowed to dry
by reapplying the product as needed for the required contact
time (30 minutes). Solids should be removed from surfaces
prior to treatment or removed from the waste stream prior to
discharge. Contaminated material that is removed from the
waste stream should be processed through alkaline
hydrolysis, disposed in a muncipal solid waste landfill, or
incinerated. Because of the pollutant properties of the
chemicals and formulations used in the inactivation of the
CWD agent, laboratories must comply with applicable Federal,
state, and local environmental regulations regarding
discharge of these solutions.

Recommended Best Management Practices (BMPs)

EPA Region 8 has developed recommended BMPs for laboratories
that handle potentially CWD-contaminated materials in order
to minimize any potential risk to the environment. These
recommendations are based on available information and
consultation with affected laboratories, universities, and
Federal, state, and local regulatory and research agencies.

The American Association of Veterinary Laboratory
Diagnosticians’ (AAVLD) Laboratory Safety and Waste Disposal
Committee and Pathology Committee have developed best
management practices that offer disposal guidance for
CWD-contaminated waste from laboratory professionals (AAVLD
2004). EPA Region 8 considered and has incorporated a
number of recommendations relevant to environmental
protection from the AAVLD document. The practices
recommended by AAVLD that have been directly incorporated
are indicated by an (*) asterisk. The rest of the
recommended practices have been adapted from AAVLD by Region
8 to maintain consistency with this document’s focus.

Necropsy Laboratories (carcasses, heads, vertebral columns,
and other unfixed tissues) *

Disposable or dedicated equipment, instruments, and supplies
should be used when possible when CWD-suspect necropsies are

All formalin fixed and unfixed samples from CWD suspects
should be marked with “CWD Test Sample.”

Necropsy drain(s) should be screened to trap tissue
fragments and large blood clots, to minimize the amount of
potentially infectious material entering drains. *

Appropriate disinfectants (below) should be used on
potentially contaminated, hard, nonporous surfaces prior to
washing. *

Minimal volumes of surface and floor wash water should be
used during necropsy and clean up.

Instruments should be placed in disinfectant solution and
work surfaces should be kept wet during necropsy to minimize
drying of tissues and body fluids.

Receptacles should be used to catch fluid wastes from
necropsy tables and suspended decapitated carcasses.
Absorbable materials are an alternative, but will generate
undesirably large volumes of waste when many samples are
processed. *

Carcasses, tissues, and potentially contaminated disposable
materials should be disposed of by one of the following

$ Burn in a pathological waste incinerator with one second
retention times in the secondary chamber and a minimum
secondary chamber temperature of 1600o - 1800o F
(871o - 982o C), * or
$ Digest in alkaline hydrolysis units for at least 6 hours
at 300o F (149o C), * or
$ Landfill in accordance with local and state regulations
and EPA interim practices.

Non-disposable items from necropsy should be cleaned with
appropriate treatments as follows:

5 - 9% aqueous acid phenolic solution of for >30 minutes, or
0.9% solution for 16 hours. 1

Prior to disposal, sharps and containers should be soaked in
5 - 9% aqueous acid phenolic solution for >30 minutes or
0.9% solution for 16 hours, 1 and then disposed of in
landfills in accordance with local and state regulations and
EPA interim practices or by proper incineration.

Following necropsy, the floor and potentially contaminated,
hard, nonporous surfaces should be soaked with 5 - 9%
aqueous acid phenolic solution and kept wet for >30 minutes.

Histology Laboratories *

Disposable or dedicated equipment and supplies should be
used when possible. *

CWD-suspect tissues should be grossed in for histology in
chemical hoods using dedicated or disposable instruments and
cutting boards.

Potentially contaminated formalin or other liquids should be
incinerated or recycled with appropriate disposal of
remaining solids (incineration, alkaline hydrolysis), or
chemically neutralized and disposed of in accordance with
Federal, state, and local regulations. *

Prior to disposal, sharps and containers should be soaked in
5 - 9% Environ LpH solution for >30 minutes or 0.9% solution
for 16 hours, 1 and then disposed of in landfills in
accordance with local and state regulations and EPA interim
practices or by proper incineration.

All CWD-suspect tissues for histologic processing should be
separately identified (i.e., unique case number or specific
color of tissue cassettes for CWD-suspect tissues).

All microtomy wastes will be collected and disposed of as
for fresh tissues.(see necropsy section)*

Formalin-fixed tissues from CWD-infected animals should be
disposed of as for fresh tissues (see necropsy section).

Waste solutions should be treated by adding concentrated
aqueous acid phenolic solution to give a final concentration

5 - 9% solution for 30 minutes, or 0.9% solution for 16
hours. 1

Processing, embedding, staining, and microtomy equipment
should be frequently treated with appropriate
CWD-inactivating solutions.

Laboratories Handling Fresh Tissues from CWD Suspect Animals

Fresh tissues from CWD suspects should be processed in such
a way that excess fluid and tissue can be captured either by
receptacles or absorbent pads. This waste will be disposed
of by proper incineration, alkaline hydrolysis, or
landfilling in accordance with local and state regulations
and EPA interim practices.

Instruments used for potentially infected tissues should be
placed in a 5 - 9% aqueous acid phenolic solution for >30
minutes, or 0.9% solution for 16 hours. 1

Waste solutions will be treated as described above prior to
washing down the sink. *

Prior to disposal, sharps and containers should be soaked in
5 - 9% aqueous acid phenolic solution for >30 minutes or
0.9% solution for 16 hours, 1 and then disposed of in
landfills in accordance with local and state regulations and
EPA interim practices or by proper incineration.

Contaminated, hard, nonporous surfaces will be disinfected
as described in necropsy section. *

Literature Cited and References

American Association of Veterinary Laboratory Diagnosticians
(2004) Best Management Practices for Handling Suspect Biosaf
ety Level 2 Animal Transmissible Spongiform Encephalopathy
(TSE) Diagnostic Samples (Scrapie, Chronic Wasting Disease
and Transmissible Mink Encephalopathy) in Animal Health

Brown P and Gajdusek DC (1991) Survival of scrapie virus
after 3 years’interment. Lancet 337:269-270.

Centers for Disease Control and Prevention (CDC) (2003a)
Fatal degenerative neurologic illnesses in men who
participated in wild game feasts – Wisconsin 2002. Morbidity
and Mortality Weekly Report 52:125-127. February 21, 2003.

Centers for Disease Control and Prevention (CDC) (2003b)
Guidelines for environmental infection control in
health-care facilities. Recommendations of CDC and the
Healthcare Infection Control Practices Advisory Committee
(HICPAC). Morbidity and Mortality Weekly Report 52:1-42.
June 6, 2003.

Environmental Protection Agency (EPA) (1994) BID for Medical
Waste Incinerators - Proposed Standards and Guidelines:
Control Technology Performance Report for New and Existing
Facilities, EPA-453/R-94-044a. Office of Air Quality
Planning and Standards. July 1994.

Environmental Protection Agency (EPA) (2004a) Letter from
James J Jones, Director, Office of Pesticide Programs to Don
Ament, Commissioner, Colorado Department of Agriculture.
File Symbol: 04-CO-02. March 4, 2004. See also letters to
N. Dakota, S. Dakota, Utah, and Wyoming.

Environmental Protection Agency (EPA) (2004b) Memorandum
from Robert Springer, Director, Office of Solid Waste to
RCRA Division Directors (Regions I-X), Superfund Division
Directors (Regions I-X), and OSWER Office Directors.
Recommended Interim Practices for Disposal of Potentially
Contaminated Chronic Wasting Disease Carcasses and Waste.
April 6, 2004.

Miller MW, Williams ES, Hobbs NT, Wolfe LL (2004)
Environmental sources of prion
transmission in mule deer. Emerging Infectious Diseases
[serial on the internet, e-published ahead of print].

Miller MW, Wild MA, Williams ES (1998) Epidemiology of
chronic wasting disease in Rocky Mountain elk. Journal of
Wildlife Diseases 34:532-538.

O’Rourke KI, Besser TE, Miller MW, Cline TF, Spraker TR,
Jenny AL, Wild MA, Zebarth GL, Williams ES (1999) PrP
genotypes of captive and free-ranging Rocky Mountain elk
(Cervus elaphus nelsoni) with chronic wasting disease.
Journal of General Virology 80:2765-2769.

Palsson PA (1979) Rida (scrapie) in Iceland and its
epidemiology. In: Prusiner SB, Hadlow WJ (Eds.) Slow
transmissible diseases of the nervous system, Vol. I.
Academic Press, New York NY; pp. 357-366.

Sigurdson CJ, Williams ES, Miller MW, Spraker TR, O’Rourke
KI, Hoover EA (1999) Oral transmission and early lymphoid
tropism of chronic wasting disease PrPres in mule deer fawns
(Odocoileus hemionus). Journal of General Virology

Williams ES and Miller MW (2002) Chronic wasting disease in
deer and elk in North America. Review Scientifique et
Technique, Office International des Epizooties 21:305-316.

World Health Organization (1999) Infection control
guidelines for transmissible spongiform encephalopathies.
Report of a World Health Organization consultation. Geneva,
Switzerland, March 23-26, 1999. WHO/CDS/CSR/APH/2000.3,

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