United States
  Environmental Protection
Wastewater Response Protocol
Planning For and Responding To
Wastewater Contamination
Threats and Incidents
December 2011
Module 5:
Public Health and Environmental Impact
Response Guide

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                         Table of Contents - Module 5

1 Introduction	 5-1
2 Plan the Public Health/Environmental Response (Pre-threat Phase)	5-1
3 Determine the Public Health Consequences and Environmental Impacts Resulting
  from the Contamination Event (Post-threat Phase) 	5-3
4 Implement Appropriate Operational Responses (Post-threat Phase)	5-4
5 Implement the Public Notification Strategy (Post-threat Phase)	5-5
6 Make Available Short Term Alternate Sanitary Services (Post-threat Phase)	5-6
7 Summary	5-7
8 Appendices	5-7

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                                    Planning and Preparation
                                         Threat Warning
                                    Initial Threat Evaluation
Immediate Operational
  Response Actions
                                      Site Characterization
                                         and Sampling
                                         Public Health
                                       Response Actions
                                        Sample Analysis
                                          Is Incident

                                   Remediation and Recovery
                              Wastewater Response Protocol Toolbox

1 Introduction

Module 5 provides guidance for the public
health and environmental protection response
to a wastewater contamination threat or
incident. The response is one component of
the overall threat management process which
is described in Module 2, the Contamination
Threat Management Guide. This response
includes those actions taken by utilities, health
entities, and regulatory agencies to decrease
the public health  and safety consequences, as
well as negative effects on the environment,
which may result from a contamination threat
or incident. Public health and environmental
responders in this context include the utility,
local and state health and environmental
departments, the  EPA, and the Centers for
Disease Control and Prevention because
they may all  be involved in choosing and
implementing the public health/environmental
response actions  taken during a contamination

The public health and environmental
protection response consists of the five
actions listed below:
Action taken before a threat occurs
   Plan the public health and environmental
Actions taken after a threat occurs
   Determine the public health and
    environmental consequences resulting
    from this particular wastewater
    contamination incident
   Implement appropriate operational
   Implement public notification
   If necessary,  make available short term
    alternate sanitary services
2 Plan the Public Health/
  Environmental  Response
  (Pre-threat Phase)

The public health/environmental response
should be planned and coordinated between
utilities, public health agencies, and
environmental regulatory agencies before a
threat occurs. Utilities document their planning
when preparing their Emergency Response
Plan (ERP). State and local health agencies
typically develop a Public Health Response
Plan that covers responses to all types of public
health emergencies (including but not limited
to water emergencies). Regulatory agencies
have developed extensive environmental
protection plans to be used in response to a
variety of contingencies. In their planning,
utilities, health agencies, and regulatory
agencies should address several issues as they
relate to a response in the event of a threatened
or actual contamination event in a wastewater

First, during the planning phase, the roles
and responsibilities of the agencies involved
in public health and environmental impact
response should be identified. At this point, the
utility should define its intended role in future
public health/environmental impact responses.


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          Secondly, an effort should be made to integrate
          public health and environmental protection
          agency planning into the utility's ERP. The
          utility should investigate how the public
          health response plans of local and State health
          departments, and the environmental protection
          plans of regulatory agencies, address
          wastewater contamination incidents. They
          should then integrate appropriate portions of
          these plans into the utility ERP.
          The utility should also develop a
          communications strategy. Rapid and reliable
          communications are crucial to ensuring a
          prompt and coordinated public health and
          environmental response. Plans  should be made,
          prior to an incident, that describe who should
          be notified, when and how they should be
          notified, and what types of information they
          should be given consistent with any applicable
          laws and regulations. A backup communication
          and notification system should be put into
          place in the event that phone networks are
          not functioning. Those notified may include
          emergency responders,  government and non-
          governmental agencies, critical customers
          such as hospitals, and the public. Especially
          important is two-way communication
          between wastewater utilities and public health
          agencies. The Incident Commander (who
          may or may not be from the utility) should
          report contamination threats to the public
          health agency so that physicians and hospitals
                                                       can be on alert to report potential signs and
                                                       symptoms to the health department. Similarly,
                                                       public health agencies should communicate
                                                       with wastewater utilities regarding unusual
                                                       symptoms being reported by the medical
                                                       community that may have a connection to

                                                       Finally, prior to a threat being received, the
                                                       involved organizations should develop plans
                                                       for operational and public health responses
                                                       to be taken during a threat or incident. The
                                                       operational steps should be designed to
                                                       minimize the impact of a contamination event
                                                       on public health  and the environment. The plan
                                                       should identify the agency or organization that
                                                       is responsible for carrying out the action(s), as
                                                       well as the circumstances under which certain
                                                       actions are to be taken. The organizations
                                                       should also assess the feasibility and potential
                                                       effectiveness of these operational steps. At the
                                                       same time these  agencies should determine the
                                                       potential impacts of specific  response actions
                                                       on the community.
                                                       It is during the planning phase that gaps in
                                                       operating procedures, technical capabilities,
                                                       and communications should be identified
                                                       and addressed. As with all response plans,
                                                       regularly exercising the public health/
                                                       environmental impact plan is critical to
                                                       effective implementation during an emergency.
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Exercises should involve not only the utility
but also health agencies, regulatory agencies,
and public safety response agencies.

The remaining four actions, described
below, should be taken following the utility
becoming aware of an accidental or intentional
contamination threat. These actions may
be taken individually, or in combination, at
any point throughout the threat management
process. However some actions may be
required to be taken at specified times.
3 Determine the Public
  Health Consequences and
  Environmental Impacts
  Resulting from the
  Contamination Event
  (Post-threat Phase)

Once the possible identity of the contaminant
(or contaminants) has been determined, the
utility and other responders should obtain
information on the properties and potential
health and safety consequences of the
contaminant, as well as possible impacts on
the environment and wastewater operations.
This information will help inform response
decisions.  Some public health/public safety
factors of concern include the acute and
chronic health effects of human exposure to the
contaminant, exposure routes of concern (e.g.,
inhalation or dermal contact), contaminant
concentrations that are toxic or infective, and
the flammability of vapors. Environmental
factors of concern include the stability of the
contaminant in water and the potential impact
of the contaminant on living organisms in the
receiving waters as well as on downstream
users of the receiving waters (e.g., drinking
water utilities). Operational concerns include
the ability of wastewater treatment processes to
remove or inactivate the contaminant, as well
as the contaminant's potential to damage the
biological treatment process in  the wastewater
A good source for information on properties,
health effects, and environmental impacts
of a variety of chemical, biological, and
radiological contaminants of concern for
drinking water and wastewater is EPA's Water
Contaminant Information Tool (WCIT).
For these contaminants, WCIT provides
information about relevant topics such as
chemical or pathogen properties, medical
aspects, toxicity, as well as decontamination
methods for wastewater infrastructure and the
effect of wastewater treatment processes on
contamination concentrations. Access to this


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secure, web-accessible database is available
to water utilities, regulators, health agencies,
and others free of charge. However, prior
registration is required. Additional information
on WCIT is available at http://www.epa.gov/

Another factor relevant to determining the
consequences of a contamination event
is assessment of the actual spread of the
contaminant in the wastewater system.
This assessment can be accomplished using
manual methods which are  simply based on
the utility's knowledge of flow patterns in the
collection system. The assessment can also be
conducted through the use of hydraulic models
such as EPA's SewerNet.

SewerNet is an integrated, GIS-based
simulation model for consequence assessment
of sanitary and storm water collection
systems affected by contamination events.
It can be applied to any storm, sanitary, or
combined sewer system. The model is capable
of predicting the routing of contaminated
storm water and/or sanitary flow through the
sewer network, from points of collection to
treatment facilities or direct discharge points.
It can account for chemical transformations
and losses that might occur during transport,
such as volatilization or adsorption onto pipe
walls, and can analyze the consequences of a
variety of contamination scenarios. Additional
information on SewerNet is available at the
following website:

The Contaminant Characterization and
Transport Worksheet (Appendix 13) is a form
that could be used to help organize information
that will lead to the identification of the
contaminant. It can also facilitate decisions
on appropriate operational responses and
provide more accurate information for public

4 Implement Appropriate
  Operational  Responses
  (Post-threat Phase)

Certain operational responses, identified during
the pre-threat phase planning process, may
be implemented in response to a 'Possible'
or 'Credible' contamination threat. The
objectives of operational response actions
should be to minimize exposure of the
public and wastewater system employees
to the contaminated wastewater, decrease
the negative impact on the environment,
lessen the potential impact on the wastewater
infrastructure, and provide additional time to
evaluate whether or not the threat is 'Credible'
or 'Confirmed.' Some operational responses
include the following and can be implemented
if consistent with applicable laws and

   Isolate and store contaminated wastewater
    (e.g., in backup storage basins or tanks, if
   Slow the influent flow of wastewater
    into the treatment plant to permit more
    extensive treatment.
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    Isolate redundant unit wastewater
    treatment processes, if available, to
    prevent the contaminant from damaging
    the entire treatment process.
    Increase disinfectant concentrations to
    reduce the passage of infectious pathogens
    through the treatment plant and into the

Because some of these actions could violate
permit conditions or the Clean Water Act,
these actions should only be taken after
consultation with the regulatory agency. If
the utility is considering a bypass, the utility
should note that the conditions for a bypass
are described in 40 CFR 122.41(m). If the
permittee knows in advance of the need for a
bypass, it shall submit prior notice at least ten
days before the date of the bypass, if possible.
In the case of an unanticipated bypass, the
permittee shall submit on 24 hour notice if the
following conditions are met: (A) bypass was
unavoidable to prevent loss of life, personal
injury, or severe property damage; (B) there
were no feasible alternatives to the bypass, and
(C) the permittee submitted notices as required
under paragraph (m)(3) of this section. CWA
Section 301(f) governs the discharge of any
radiological, chemical, or biological warfare
agent, any high-level radioactive waste, or any
medical waste, into the navigable waters. The
cost of restoring the contaminated plant versus
the environmental and economic damage to
the watershed must be carefully considered. In
addition, downstream drinking water treatment
plants should be notified since this could
impact their ability to provide safe drinking
water to the public.

The Public Health Response Action Worksheet
in Appendix 14 can be utilized to organize
information to aid in the evaluation of
containment options, issuance  of public
notification, and provision of alternate sanitary
5 Implement the Public
  Notification Strategy
  (Post-threat Phase)

Public notification will be a key component of
an effective response to a 'Credible' threat or
'Confirmed' incident. It may also be required
by applicable laws and regulations.  Public
notification may be needed to reduce or
mitigate exposure to a contaminant and prevent
panic. In the case of a 'Credible' contamination
threat, if time allows, the utility should consult
with the wastewater primacy agency, and the
public health agency, to determine whether or
not the situation warrants public notification.

Once the decision has been made to notify
the public, it is important to evaluate the type
of information that should be delivered to
the public. Any available information about
the suspected contaminant will support the
process of developing a notification message.
If the identity of the contaminant is known
with a sufficient degree of confidence as a
result of the threat evaluation, then the public



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notification may be crafted to deal with the
specific risks to public health and safety posed
by the contaminant. At a minimum generally,
the public notification could include:

    Description of the contaminant
    How the contaminant was introduced into
    the wastewater system
    Geographical extent of the affected area
    Potential risks to which the public may
    be exposed (e.g., explosive fumes and/or
    toxic vapors)
    Protective actions the public should take
    (e.g., evacuation)
    Actions being taken by authorities to
    control the situation
    Reassurance that the public will be kept

In an extreme situation, it may become
necessary to advise the public not to flush
toilets (Do Not Flush order). This could occur,
for example, if the drinking water supply had
become contaminated with substances that
present an inhalation risk if aerosolized or
volatilized.  In this situation, the public would
probably also receive a Do Not Use order for
the drinking water system. In the event that it
becomes necessary to communicate with the
public concerning a contamination  event in
the wastewater system, the communication
will most likely occur through the media
(TV, radio, newspapers). Methods such as
email notices, reverse 911, and door-to-door
notifications may also be used. To facilitate this
communication, and maintain the credibility
of the utility, as well as public health and
regulatory agencies, it is important to maintain
a communications plan, try to establish a
working relationship with the local media
prior to an event, and deal with the media in a
forthright manner.

6 Make Available Short Term
  Alternate Sanitary Services
  (Post-threat Phase)

In the event that the wastewater collection
system, or a portion of it, is temporarily not
usable, the response will have to include
provision of alternate sanitation options. A
similar situation occurred in the past when
portions of the wastewater collection system
were destroyed by explosions in Akron, Ohio
(1977) and Louisville, Kentucky (1981) as
described in Module 1 of the Toolbox. Options
for temporary sanitary facilities may include
deployment and maintenance of portable
toilets, home waste treatment devices, or
packaged systems.
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The wastewater utility and local authorities
may or may not have the resources to provide
alternate sanitation facilities. In the event
that local resources are overwhelmed,  state
and federal agencies may need to provide

7 Summary

The public health and environmental response
to an intentional or accidental wastewater
contamination event includes the actions taken
to control the public health/safety, property/
infrastructure damage, and environmental
consequences resulting from biological,
chemical or radiological  contaminants.

The utility should plan the response with
other organizations prior to receipt of a threat.
This includes identification of the roles and
responsibilities of agencies involved in the
response, development of a communication
strategy, and evaluation of the feasibility of
various  operational responses.

Once the utility and other responders
become aware of a contamination threat,
they should determine the public health and
environmental consequences resulting from
the contamination, implement operational
responses, notify the public, and if necessary,
provide alternate sanitary services.

Much of the success of the public health and
environmental response depends on adequate
pre-planning and effective communications
among all the response organizations involved.
8 Appendices

The following are examples of forms that may
be used to facilitate the public health response:
    Contaminant Characterization and
    Transport Worksheet
    Public Health Response Action Worksheet
These forms can be found in the Appendices
located at the end  of the Toolbox.

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