Voluntary Mixing Zone Phase Out Strategy

Prepared by:

Chesapeake Bay Program's
Pollution Prevention and Point Source Workgroup
Of the Toxics Subcommittee

To Address:

The Zero Release Objective in the Chesapeake 2000 Agreement

and

The Mixing Zone Phase Out Goal in the Toxics 2000 Strategy

Draft Date: August 10, 2001


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The following text is quoted from the Chesapeake 2000 Agreement and the Toxics 2000
Strategy to provide the reader with the origin of the decision to seek the voluntary
elimination of mixing zones by point sources discharging persistent or bioaccumulative
toxics in permitted concentrations greater than the applicable water quality standard at
"end of pipe". These are final and approved commitments by the Chesapeake Bay
Executive Council.

Chesapeake 2000 Agreement Commitment:

"Through continual improvement of pollution prevention measures and other
voluntary means, strive for zero release of chemical contaminants from point
sources, including air sources. Particular emphasis shall be placed on achieving,
by 2010, elimination of mixing zones for persistent or bioaccumulative toxics"

Toxics 2000 Strategy Commitment:

To accomplish this objective, the signatories commit to:

Mixing Zone Phase Out

^Strive to meet water quality standards for persistent or bioaccumulative chemical
contaminants at the point of discharge through continual improvement of pollution
prevention measures and other voluntary means.

•	By 2001, establish a baseline for the facilities not meeting water quality
standards at the point of discharge for persistent or bioaccumulative
chemical contaminants and by 2003 and 2007 report on their progress in
reducing concentrations at the point of discharge in order to eliminate mixing zones.

•	An initial emphasis shall be placed on phasing out mixing zones for persistent or
bioaccumulative chemical contaminants in the following areas:

-	Regions of Concern,

-	Areas of Emphasis,

-	303(d) listed waters for persistent or bioaccumulative chemical contaminants,

-	Areas under finfish or shellfish advisories caused by persistent or
bioaccumulative chemical contaminants.1

1- Where field monitoring exists to support an advisory.


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Mixing Zone Phase Out Strategy
IC Draft - September 18, 2001

Background:

A voluntary mixing zone phase out is one action of many needed to achieve the "zero
release" goal that industries and Chesapeake Bay stakeholders have agreed to in the
Chesapeake 2000 Agreement. Addressing mixing zones for persistent or bioaccumulative
toxics will result in the reduced potential for acute and chronic impacts to aquatic
resources and human health. The advantage of using voluntary means gives point source
dischargers the opportunity to choose how and when to phase out their mixing zones.

Who created this strategy?

The Pollution Prevention and Point Source workgroup of the Toxics Subcommittee has
been charged with developing this draft Voluntary Mixing Zone Phase Out Strategy to
achieve a voluntary elimination of point source mixing zones for persistent or
bioaccumulative toxics.

A targeted approach for implementation:

Persistent or bioaccumulative toxics:

The Strategy defines persistent or bioaccumulative toxics as toxic contaminants
that persist, contaminants that bioaccumulate, and contaminants that both persist
and bioaccumulate. The workgroup is currently developing and selecting an
initial list of contaminants for addressing this phase out. The list will be reviewed
and updated on a periodic basis. Each jurisdiction or watershed will also prioritize
efforts based on local water quality issues and risk. (See page 3 for the persistent
or bioaccumulative list)

Geographic Priorities:

This strategy places an initial emphasis on phasing out mixing zones for persistent
bioaccumulative toxics following the geographic focus of the Toxics 2000
Strategy.

•	Regions of Concern,

•	Areas of Emphasis

•	303(d) listed waters for persistent or bioaccumulative chemical
contaminants and

•	Areas under finfish or shellfish advisories caused by persistent or
bioaccumulative chemical contaminants.

This effort will expand to the rest of the Chesapeake Bay watershed after the
focus areas have been assessed. Facilities outside of these focus areas identified
in the mixing zone baseline as not meeting water quality standards at the point of
discharge for persistent or bioaccumulative chemical contaminant will be
evaluated in 2003 on their progress in reducing concentrations at the point of
discharge. Based on that evaluation, each jurisdiction or watershed will also
prioritize efforts based on local water quality issues and risk. In 2007, all

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Mixing Zone Phase Out Strategy
IC Draft - September 18, 2001

facilities will again be evaluated for progress in reducing concentrations at the
point of discharge and further action plans developed as necessary.

Mixing Zone Phase Out Priority:

Recognition will be given to any facility that voluntarily phases out its mixing zone for
any pollutant. In addition to the geographic priorities noted above and due to limited
resources, the following list represents an additional prioritization component base on the
mixing zone itself.

1.	Mixing zones in compliance with permit limits based on the size of the mixing zone
and the concentration or loading of contaminant

2.	Mixing zones already attaining the water quality standard at end of pipe

3.	Other releases above water quality standards (variances that exceed end of pipe water
quality standards). For example, mixing zones in PA are prohibited instead they are
called effluent compliance time areas.

Variants of mixing zones will also be evaluated in this process. The impact of mixing to
determine reasonable potential in the NPDES permitting process (e.g., the cause and
effect of reasonable potential decision that results in no permit limit for a pollutant, the
decision based on the high cost to make a marginal decrease in pollutant loading),
administrative mixing assignments in reasonable potential determination and outfall
relocation (all in relation to persistent or bioaccumulative toxics) will be reported on in
2003 and 2007. Any new mixing zone for persistent or bioaccumulative pollutants
initiated after December 2000 will be evaluated and reported in 2003 and 2007.

Implementing the Strategy:

The strategy focuses on six main areas. An expanded explanation of each bullet point is
provided in the following sections, which make up the steps for tracking strategy
implementation success:

1.	Profile the mixing zone situation in the Bay watershed and establish a baseline from
which to measure progress.

2.	Conduct outreach and education of point sources and the general public within the
Bay watershed.

3.	Provide technical assistance, identify technology needs and identify incentives as
mixing zone elimination projects are initiated by point sources.

4.	Provide recognition for point sources voluntarily phasing out mixing zones.

5.	Close the deal- A step by step example of how to educate, encourage, secure, and
complete a voluntary mixing zone phase out.

6.	Tracking progress towards meeting the commitment

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Mixing Zone Phase Out Strategy
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I. Profile the Mixing Zone Situation in the Bay and Establish a Baseline from
which to Measure Progress

A). Select a discrete list of chemicals to be used in the initial mixing zone

Profiling and Baseline Determination:

The following list of chemicals will be used in a baseline analysis to identify mixing
zones that exist in the Chesapeake Watershed for these contaminants. This list is to be
dynamic and represents a first cut for analysis purposes. Chemicals will be added as
new data becomes availability to justify their inclusion on the list.

The following list of contaminants were selected based on the following criteria that was
applied to the EPA's PBT list and the Chesapeake Bay Program's Chemicals of Concern
list (appendix A):

A.	Appearance on EPA's PBT list or Appendix A of the Toxics 2000 Strategy's
Appendix A- Chemicals of Concern list.

B.	Must be discharged by a point source and have a water quality standard.

C.	The eight metals have been selected based on the Mixing Zone Task Force, work
group expertise, and the Toxics Subcommittee input.

D.	Must be either a persistent contaminant or bioaccumulative contaminant, or both

E.	This list is only for data analysis purposes.

1.	Mercury and its	4.	Copper	9. PAHs 1
compounds	5.	Arsenic	10. PCBs 2

2.	Lead and its	6.	Cadmium	11. Hexachlorobenzene
compounds	7.	Nickel	12. dioxins and furans

3.	Chromium	8.	Zinc	13. Octachlorostyrene

By 2003, expand the analysis to a) facilities outside the initial focus area (throughout the
Bay Watershed), and b) any new chemicals responsible in the areas of initial focus (see
the four bullets under the mixing zone commitment) the initial focus areas and c) "non-
limited" mixing zones. Final analysis will include all facilities "not meeting water
quality standards at the point of discharge for persistent or bioaccumulative chemical
contaminants"

While the following banned substances are recognized as persistent or bioaccumulative
toxics, they are not expected to have a mixing zone. Thus they will not be included in
this analysis:

Aldrin/Dieldrin	Chlordane	Toxaphene

Mirex	DDT, DDD, DDE	Kepone

1-	Polyaromatic hydrocarbons- a group of specific chemical contaminants

2-	Polychlorinated Biphenyls- another group of chemical contaminants

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Mixing Zone Phase Out Strategy
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B) The protocol to identify mixing zones that involves the selected list of chemicals
includes the following:

1)	The CBPO will construct a list of the point source facilities in the Bay watershed that
are in our Toxics Point Source database that are major facilities. The State and
District Jurisdictions will be responsible for conducting the analysis and tracking
progress. Data will be shared with the Bay Program for tracking purposes.

2)	Initially focus the analysis on the Regions of Concern (ROC) and the Areas of
Emphasis (AOE) to determine a protocol. Apply protocol to 303(d) listed waters for
persistent or bioaccumulative chemical contaminants and Areas under finfish or
shellfish advisories caused by persistent or bioaccumulative chemical contaminants.
Finish this analysis by 2001.

3)	By 2003, expand the analysis to a) facilities outside the initial focus area (throughout
the Bay Watershed), and b) any new chemicals listed as being responsible for
impairments in the areas of initial focus (see the four bullets under the mixing zone
commitment) and c) "non-limited" mixing zones. Final analysis will include all
facilities "not meeting water quality standards at the point of discharge for
persistent or bioaccumulative chemical contaminants".

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Mixing Zone Phase Out Strategy
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II. Conduct outreach and education of point sources and the general public
within the Bay watershed.

ACTION: Organize a series of topic specific Industry and POTW Roundtables to get
buy-in from environmental managers and corporate senior level
management on the voluntary mixing zone phase out and Chesapeake Bay
Program goals. Topics to be addressed include:

•	Environmental benefits for the phase out

•	Industry benefits to phasing out mixing zones

•	Recognition

•	Incentives- (e.g., Can regulatory flexibility be explored?)

•	Barriers to pursuing a voluntary phase out

•	Funding opportunities

•	Industry Compliance policies

•	Pollution Prevention and treatment technologies
Progress: Plan state specific roundtables to introduce the concept,

initially. As follow up, explore other relevant topics.

Invite all pertinent stakeholders to meetings.

Schedule: Once facility lists are developed, roundtables can be

organized by February of 2002
Funding: Businesses for the Bay, EPA/State Pollution Prevention
Programs.

Partners: Businesses for the Bay, EPA/State Pollution Prevention
Programs.

ACTION: Develop and provide presentations (i.e., industry-to-industry and Bay
Program-to-industry) to Industry and Treatment Works about the
voluntary mixing zone phase out in order to inform them of the Strategy,
generate buy-in, and publicity. Presentations will include environmental
need and benefits, industry benefits, barriers, technologies, and solutions
to achieving the voluntary phase out as identified in the Industry
Roundtables.

Presentations will be tested first on the Pollution Prevention and Point
Source Workgroup for accuracy and consistency of message and then
tested on a focus group of industry trade associations or water federations
for feedback before presenting the final product to industry. Presentations
will take place throughout the duration of the Strategy and will include
updates to keep industry informed of the progress on the mixing zone
phase out effort.

In addition, presentations will include information on how to obtain
technical assistance from voluntary programs for mixing zone phase out as
well as other pollution prevention areas (e.g., Businesses for the Bay, state
assistance programs, etc.).

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Mixing Zone Phase Out Strategy
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Progress:	Development and trial testing in progress.

Schedule:	Complete by end of 2001.

Funding:	N/A.

Partners:	Point Source and Pollution Prevention Workgroup.

ACTION: Create a fact sheet to distribute as an outreach/education tool to inform
businesses and the public on the context of this targeted pollution
prevention effort; include information on technical assistance
opportunities. Draft follow up fact sheets/newsletters that target specific
topic areas (e.g., incentives, regulatory flexibility, and contaminants )

Progress: Draft of initial fact sheet is completed. Waiting on Bay

Program communications review
Schedule: Develop mailing lists or e-mailing lists for distribution:

utilize existing organizations such as AMSA, VAMWA, or
others to disseminate. Send out after completion of
strategy to begin the outreach efforts. Distribute as needed
bi-annually and post on Chesapeake Bay Program web site.
Funding: N/A

Partners: Businesses for the Bay, Elizabeth River Project, Anacostia
River Business Coalition, VAMWA, AMSA, and other
community and industry organizations. Utilize listserv and
other publication means.

ACTION: Publish mixing zone articles in technical journals and highlight case
studies for national recognition. Target group: consultants and other
engineers.

Progress: Once baseline and facility lists are established. Seek Bay

watershed facilities or national case studies.

Schedule: Submit an introductory article on the voluntary phase out.

Submit follow up articles based on survey of facilities.
Funding: N/A

Partners: Point Source and Pollution Prevention Workgroup,
Facilities with mixing zone phase out success.

Watershed Outreach:

ACTION: Submit articles periodically to newspapers, the Bay Journal and other Bay
publications to educate citizens, communities, local governments and
other partners about the voluntary mixing zones phase out. Articles will
vary beginning with a background article talking about the baseline and
overall concept.

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Progress:

Schedule:

Funding:
Partners:

Mixing Zone Phase Out Strategy
IC Draft - September 18, 2001

An article has been produced in the June 2000 Bay Journal,
which introduces the commitment and provides background
on the origin of the commitment.

Publish background/update article in Fall 2001 Bay
Journal. Publish follow up articles to highlight
accomplishments and progress. Promote first voluntary
phase out in local/national media.

N/A

Alliance for the Chesapeake Bay, Bay Program's
Communication Office, State Communication Offices, and
other journalists (e.g., Tom Horton, Baltimore Sun).

ACTION: Create a webpage on the Bay Program's website that explains the mixing
zone concept to citizens, businesses, and decision-makers. Site will cover
the scope of this initiative, timeline, and other important information.

Progress: Draft will be available soon for review
Schedule: Completion date: Summer 2001
Funding: N/A.

Partners: Pollution Prevention and Point Source Workgroup and the
Toxics Subcommittee

ACTION: Get air time on television to highlight the voluntary phase outs or other
progress made by industry and the partners involved.

Progress:

Schedule: Determine appropriate case study to highlight and time to

approach news stations.

Funding: N/A

Partners: Public television, major news stations, technical stations
(e.g., Discovery), and the Bay Program Communications
Team.

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Mixing Zone Phase Out Strategy
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III. Provide technical assistance, identify technology needs and identify

incentives as mixing zone elimination projects are initiated by point sources.

ACTION: EPA/States will sponsor workshops to identify technology needs and areas
for further pollution prevention (e.g. pretreatment programs and consumer
product contamination) that would aid in implementation of pollution
reduction activities and mixing zone elimination for contaminants
identified in this Strategy.

Progress:

Schedule:

Funding:

Partners:

Schedule at least one per state to begin this initiative, could
be part of initial roundtable discussions. A special session
during the 2002 Zero Release Conference will contain a
session on technology needs.

2002

Alliance for the Chesapeake Bay
Innovative Technologies Matrix Task Force, National
Pollution Prevention Roundtable, State P2 Programs, and
Businesses for the Bay.

ACTION: CBPO will evaluate and synthesize the results of a EPA headquarters

mixing zone phaseout cost analysis and industry and POTW case studies
to provide examples of potential cost benefits and costs to voluntarily
phase out a mixing zone.

Progress:

Schedule:

Funding:
Partners:

EPA HQ has conducted an economic analysis. We are
working on getting that analysis to see what information
can be utilized in our outreach/marketing/education efforts.
Chesapeake Bay as well as national case studies will be
sought.

Workgroup needs to evaluate usability of this analysis by
2001 to judge whether it is usable for outreach and
education of Bay Watershed industries.

N/A

EPA HQ and others

ACTION: EPA/States will provide targeted technical assistance to interested

facilities through existing programs to aid in the phase out of mixing
zones.

Progress: Existing programs need to be evaluated for applicability.

Schedule:

Funding:

Partners: Businesses for the Bay Mentoring program, States non-
regulatory pollution prevention assistance, and the
Innovative Technologies Matrix.

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Mixing Zone Phase Out Strategy
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ACTION: Utilize mentor programs and other peer to peer technical assistance
programs to transfer technical assistance to those needing help

Progress: Mixing zone mentors are being currently sought.

Schedule: Mentors will help on an as needed basis.

Funding: N/A

Partners: Businesses for the Bay mentor network, Pennsylvania

Pretreatment information exchange (PIX), and other mentor
networks.

ACTION: Establish and identify mixing zone phase out projects that demonstrate

success and highlight economics, technology, pollution prevention action
and transferability to other facilities.

Progress:

Schedule:

Funding:

Partners:

Need to locate national or Bay businesses/municipalities
that have eliminated their mixing zones.

ACTION: Explore regulatory flexibility and other incentives programs to determine
what incentives can be offered to encourage the voluntary phase out of the
contaminants identified in this Strategy. Determine whether trading,
regulatory flexibility and other incentives can be explored in a voluntary
system or be linked to this initiative.

Progress:

Schedule:

Funding:

Partners:

Evaluate existing voluntary and regulatory flexibility
options for facilities from national and regional case
studies. Schedule a forum to explore these with program
managers, states, and facilities
To be determined.

To be determined.

EPA Project XL, States Environmental Council, and State
Agencies, etc.

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Mixing Zone Phase Out Strategy
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IV. Provide Recognition for Facilities Phasing out MZ

ACTION: Develop a process to recognize facilities committing to phase out mixing
zones. Encourage facilities committed to mixing zone phase out to
develop long term plans and milestones for press recognition and tracking
of progress. Encourage P2 options before treatment technologies.

Progress:

Schedule:

Funding:

Partners:

States and Bay Program will explore various voluntary
agreement options.

States/District/EPA/CBPO

ACTION: Recognize pollution prevention based voluntary phase outs of mixing
zones through the Businesses for the Bay Awards program or through
other pollution prevention programs awards systems.

Progress:

Schedule:

Funding:
Partners:

Evaluate other award programs to recognize facilities
completing a phase out.

Businesses for the Bay workgroup will need to approve the
award.

Businesses for the Bay and other pollution prevention
programs.

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Mixing Zone Phase Out Strategy
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V	Closing the Deal

1.	How is contact initiated with a point source complying with water quality standards
with a mixing zone?

•	Utilize the tools in the education and outreach section. States will utilize their
own individual approach for contacting each facility. Options include:

•	Director of Chesapeake Bay Program/Governor/Industry member sends a
letter to the facility manager discussing voluntary initiative and inviting
facilities for personal meeting and some background information. At the
meeting, State regulators, CBPO staff, non-regulatory pollution prevention
experts and mentors discuss initiative.

•	Organize large statewide forums with all key players above to introduce the
concept.

2.	Who follows - up?

•	Probably a non-regulatory entity. Peer mentors or pollution prevention experts.

•	At some point, state permiters will evaluate the permit for the facility.

3.	How does a voluntary project proposal to eliminate a mixing zone become an
"agreement"? Is a project proposal "approved"?

•	States/CBPO can choose a variety of options:

•	Voluntary agreements to phase out mixing zone with goals and progress
measuring points.

•	Voluntary agreements in a permit case-by-case basis.

•	Agreements in a Project XL or other regulatory flexibility option.

VI	Tracking Progress Towards Meeting the Commitment

1.	How / who will track progress of the project proposal?

•	States will submit data and reports on progress on the voluntary phaseout
initiative. The jurisdictions will explore a variety of ways to track and share
data with CBPO.

•	CBPO will develop indicators and ways to recognize facilities based on
outreach and education strategies/tools listed in previous sections.

2.	How / who will initiate the system of recognizing project in - progress or complete
(partially or completely successful)?

•	Partial success will be documented when a point source commits to phaseout out
the mixing zone for a contaminant in this strategy. Progress will be measured by
documentation of their actions taken and through monitoring data showing
consistent reduced concentrations of the contaminant at end of pipe. Partial
success will be determined when a facility is meeting the water quality standard.
Other progress can be demonstrated through monitoring data.

•	Complete success for a facility occurs when the permit is renewed without a
mixing zone.

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Mixing Zone Phase Out Strategy
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Timeline for Measuring Progress and Achieving Goals:

•	August 23, 2001: Implementation Committee review of voluntary mixing zone phase
out strategy.

•	September 31,2001: States identify facilities with mixing zones for persistent or
bioaccumulative toxics in the Regions of Concern and Areas of Emphasis.

•	December 31, 2001: Toxics Subcommittee establishes a baseline for the facilities not
meeting water quality standards at the point of discharge for persistent or
bioaccumulative chemical contaminants and selects performance measures to be
tracked.

•	December 31, 2001 States complete identification of facilities with mixing zones in
all priority geographic areas.

•	December 31, 2001 begin outreach with B4B roundtables in MD/VA/DC.

2002

•	March 31, 2002: Contact established with 25% of facilities in the priority geographic
regions identified in the baseline following implementation steps identified in the
voluntary Mixing Zone Phase Out Strategy.

•	June 30, 2002: Contact established with 50% of facilities in the priority geographic
regions identified in the baseline following implementation steps identified in the
voluntary Mixing Zone Phase Out Strategy.

•	September 30, 2002: Contact established with 75% of facilities in the priority
geographic regions identified in the baseline following implementation steps
identified in the voluntary Mixing Zone Phase Out Strategy.

•	December 31, 2002: Contact established with 100% of facilities in the priority
geographic regions identified in the baseline following implementation steps
identified in the voluntary Mixing Zone Phase Out Strategy.

2003

•	January 1 - December 31, 2003: continue implementation steps and measure
progress.

•	December 31, 2003: Toxics Subcommittee reports on the progress of facilities not
meeting water quality standards at the point of discharge for persistent or
bioaccumulative chemical contaminants in reducing concentrations at the point of
discharge in order to eliminate mixing zones.

2004

•	June 30, 2004: Contact established with 25% of facilities in the non-priority
geographic areas identified in the baseline (refined in 2003) following
implementation steps (as may be modified) identified in the voluntary Mixing Zone
Phase Out Strategy.

•	December 31, 2004: Contact established with 50% of facilities in the non-priority
geographic areas identified in the baseline (refined in 2003) following

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Mixing Zone Phase Out Strategy
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implementation steps (as may be modified) identified in the voluntary Mixing Zone
Phase Out Strategy.

2005

•	June 30, 2005: Contact established with 75% of facilities in the non-priority
geographic areas identified in the baseline (refined in 2003) following
implementation steps (as may be modified) identified in the voluntary Mixing Zone
Phase Out Strategy.

•	December 31, 2005: Contact established with 100% of facilities in the non-priority
geographic areas identified in the baseline (refined in 2003) following
implementation steps (as may be modified) identified in the voluntary Mixing Zone
Phase Out Strategy.

2006-2007

•	January 1 2006 - December 31, 2007: continue implementation steps and measure
progress.

•	December 31, 2007: Toxics Subcommittee reports on the progress of facilities not
meeting water quality standards at the point of discharge for persistent or
bioaccumulative chemical contaminants in reducing concentrations at the point of
discharge in order to eliminate mixing zones.

2008-2009

•	January 1 2008 - December 31, 2009: continue implementation steps and measure
progress.

2010

Toxics Subcommittee reports on progress to achieve elimination of mixing zones for

persistent or bioaccumulative toxics.

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Append ix-A

Back ground information on mixing zones

What did we commit to?

The Governors of MD, VA, and PA, the EPA
Administrator, the Administrator of the Chesapeake Bay
Commission and the Mayor of District of Columbia
endorse voluntary phaseout of mixing zones for
persistent or bioaccumulative toxics in Chesapeake Bay
Watershed. By signing both the Chesapeake Bay Agreement
and the Toxics 2000 Strategy, the signatories are asking that
point sources in the Chesapeake Bay Watershed commit to
the following commitments:

Zero Release Objective: To achieve the following
Chesapeake 2000 Bay Agreement commitment "Through
continual improvement of pollution prevention measures and
other voluntary means, strive for zero release of chemical
contaminants from point sources, including air sources.
Particular emphasis shall be placed on achieving, by 2010,
elimination of mixing zones for persistent or bioaccumulative
toxics.

What are mixing zones?

A mixing zone is an area where pollutants from a point
source's discharge pipe are mixed with receiving waters to
dilute the pollutants concentration. Inside a mixing zone,
discharges of the pollutant are allowed to exceed the water
quality limits set by a state. It is assumed that the brief
exceedance of the water quality standard will not
significantly impact aquatic organisms. At the boundary of
the mixing zone, the concentration of the chemical must
meet the water quality standard set for that particular body of
water. The size of mixing zones is site specific and may
vary.

How a mixing zone is determined?

Mixing zones are a legal regulatory option a point source can
choose to comply with water quality standards. Mixing
zones are site specific, scientifically based, developed
according to applicable rules, regulations and policies and
undergo rigorous regulatory review prior to issuance of a
National Pollution Discharge Elimination System (NPDES)
permit by the states and EPA. In order to issue a NPDES
permit with a mixing zone, the permitting authority has
determined that 1) the mixing zone would not cause
impairment of the receiving water, 2) There is no lethality to
organisms passing through the mixing zone and 3) there are
no significant health risks, considering likely pathways of
exposure. A NPDES permit is issued in accordance with the
administrative process act (APA) of the NPDES authority.

How will we do it?

To accomplish this objective, the signatories

commit to:

Mixing Zone Phase Out

^Strive to meet water quality standards for persistent or
bioaccumulative chemical contaminants at the point of
discharge through continual improvement of pollution
prevention measures and other voluntary means.

•	By 2001, establish a baseline for the facilities not
meeting water quality standards at the point of
discharge for persistent or bioaccumulative chemical
contaminants and by 2003 and 2007 report on their
progress in reducing concentrations at the point of
discharge in order to eliminate mixing zones.

•	An initial emphasis shall be placed on phasing out
mixing zones for persistent or bioaccumulative
chemical contaminants in the following areas:

Regions of Concern,

Areas of Emphasis,

-	303(d) listed waters for persistent or
bioaccumulative chemical contaminants,

-	Areas under finfish or shellfish advisories caused
by persistent or bioaccumulative chemical -
contaminants.

Emphasis is placed on voluntary pollution prevention
Measures to achieve this goal.

Point source
facility

What is a mixing zone?

Concentration of
contaminant briefly exceeds
water quality standard within
the mixing zone

At the Edge of mixing zone
the concentration of the
contaminant meets the
water quality standard

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Why would a point source have a mixing
zone?

Regulatory agencies have long recognized that the
potential toxicity of an effluent will tend to decrease as it
mixes with the receiving water body, simply due to
dilution. Certain regulatory procedures have evolved to
account for this tendency. These procedures result in
less stringent permit effluent limitations compared to the
limits that would be applied if dilution were ignored. In
theory these procedures can be used to develop less
stringent limits without compromising environmental
protection.

Concerns have arisen that this practice of recognizing a
"mixing zone" may not be sufficiently protective in all
cases, e.g. where sediment contamination may be an
issue. While there are often significant costs that a
discharger must bear when mixing zones are eliminated,
it may be difficult to directly identify a specific
environmental improvement that would be associated
with the elimination of a particular mixing zone.
Nonetheless, the Chesapeake Bay Program has
determined that the concerns about the reduced level of
protection associated with applying mixing zones are
sufficiently high that dischargers should be encouraged
to eliminate them whenever feasible, on a voluntary
basis.

Why phaseout mixing zones?

A voluntary mixing zone phase out is one step toward
achieving the "zero release" goal that industries have
agreed to in the Chesapeake 2000 Agreement. By 2010,
we are asking point sources to voluntarily eliminate all
mixing zones for these contaminants throughout the
watershed. In addition there are other benefits and
reasons:

Reduced acute and chronic water quality
impacts

Eliminating mixing zones will result in the reduced
potential for acute and chronic impacts to aquatic
resources from persistent or bioaccumulative toxics
briefly exceeding water quality standards in the actual
mixing zone. An elimination of mixing zones will also
result in a reduction of mass loading to the ecosystem,
especially to the sediment habitat, and a reduced
potential long term bioaccumulative impacts from that
facility. Bioaccumulative impacts from mercury and
PCBs can be seen in the fish advisories which exist in
many parts of the Bay for these substances, and in EPA's
issuance of a nationwide advisory for freshwater fish
containing mercury.

Cont'd on column 2

Continued from column 1
Reduced loadings to sediment
The 1999 Chesapeake Bay Basinwide Toxics Loading
Inventory indicates that anywhere from 60-90% of metals
such as copper and mercury are trapped in the tidal river
sediments and not flushed out of the tidal rivers. The 1999
Toxics Characterization report indicates that in some
Chesapeake Bay tidal rivers the concentrations of metals,
pesticides, PAHs, and PCBs are elevated to levels that
indicate probable adverse effects to aquatic resources. At
these levels, these chemical contaminants may be
bioavailable and impacting living resources. A voluntary
phaseout of mixing zones is one step to reduce net loadings
to the Chesapeake Bay sediments of metals and other
persistent chemical contaminants.

Limitations of the Mixing Zone designation
There are also examples of shortcomings in the design of a
mixing zone. One, mixing zones that have been established
in State's permitting policies have still resulted in unintended
benthic degradation in the mixing zone. Second, the design
may not consider the cumulative load and effect from
multiple sources of different contaminants within a mixing
zone. Another, mixing zones may be subjected to extreme
tide or environmental conditions, when these events occur
violations of the water quality standard outside of the mixing
zone edge may occur at no fault to the facility, but rather due
to a limitation in the design for normal flow conditions. For
these and other reasons, the Bay Program urges a voluntary
phaseout of mixing zones for persistent or bioaccumulative
toxics.

Benefits to the Facility

Recognition for committing to voluntary phaseout:

-	Press for committing to voluntary phaseout

-	Potential pollution prevention awards and public

exposure for environmental stewardship

-	Potential regulatory incentives

What chemicals will we focus on?

EPA's Great Lakes regulatory Mixing Zone phase out
focuses on bioaccumulative chemicals of concern (BCC).
The Chesapeake Bay Program will focus on some of the
chemicals on the BCC list, but not others because these
contaminants are not being released by point sources in the
Chesapeake Bay Watershed, although some of these "legacy
contaminants" appear to be impacting living resources from
other sources. Due to the State impaired water reports and
the Toxics Characterization report this phaseout will also
focus on metals. Data indicate these persistent toxics are
potentially impacting aquatic living resources in the
Chesapeake Bay tidal waters.

Cont'd on next page column 1

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Cont'd from previous page, column 2

The final consensus based list for the voluntary phaseout of
persistent or bioaccumulative toxics is under development.
Additionally, an effort is underway to prioritise the
chemicals to focus the phaseout. A preliminary very draft
list of focus chemicals is: mercury and its compounds, lead
and its compounds, chromium, copper, arsenic, cadmium,
nickel, zinc, PAHs, PCBs, hexachlorobenzene, dioxins and
furans, and octachlorostyrene.

Where we will focus efforts?

The Chesapeake Bay Agreement goal commits the Bay
Program to voluntarily phase out mixing zones for persistent
or bioaccumulative toxics throughout the Chesapeake Bay
Watershed. In the Toxics 2000 Strategy, it is further clarified
by the Chesapeake Executive Council to initially focus on
point sources with mixing zones for persistent or
bioaccumulative toxics located in the watersheds of the
Regions of Concern, the Areas of Emphasis, watersheds with
a fish consumption advisory or watersheds listed as being
impaired (on the 303 (d) list for each state).

What is our early implementation strategy?

A voluntary strategy to guide progress...

The Bay Program, (EPA, state agencies, pollution prevention
programs, environmental groups, publicly owned treatment
works operators, and industry representatives), is working to
identify areas to focus collective efforts of the Bay Program
to achieve this commitment over the next ten years. The
strategy contains the following focus areas:

-	Establishing a baseline of facilities

-	Education and outreach

-	Identify technological needs

-	Recognition and incentives

-	One on one targeting

-	Tracking progress

What is EPA's Policy Stance on the National
Mixing Zone Regulation?

Currently, the Administration is not proposing a regulatory
phaseout of mixing zones. They are currently evaluating
standards and criteria and it appears that mixing zones will
not be an issue or area for regulatory change.

Other EPA initiatives related to the voluntary phaseout:
EPA's PBT (persistent bioaccumulative toxics) initiative
outlines a strategy to help reduce these contaminants from
the environment as well as monitoring initiatives. Our effort
should seek to coordinate with these initiatives.

How do TMDLs affect this voluntary initiative?

Total Maximum Daily Loads may require point source
facilities to comply with stricter than water quality standards.
The voluntary mixing zone phaseout may be one step for
industries to get ahead of a proposed TMDL. However, this
will be evaluated on a case by case basis.

How will the State/Bay Program permitting
offices handle new and renewal applications for
mixing zones?

It will be the jurisdictions policy to actively explore and
encourage non-mixing zone options to new and renewal
permit applications to mixing zones.

For More Information Contact:

Bob Steidel

Hopewell Regional Wastewater Treatment Facility

804-541-2210

bsteidel@hrwtf.org

Bob Dunn
DuPont

804-383-3895

Robert.L.Dunn@USA.dupont.com
Allison Wiedeman

US EPA- Chesapeake Bay Program Office

410-267-5733

wiedema n.a 11 i so \\d coa. gov

Darin Crew

Chesapeake Research Consortium
410-267-9860

crew.darin@epa.qov

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Appendix B

Definitions for the Mixing Zone Voluntary Phaseout Strategy

303 (d) listed waters:

The 1972 Clean Water Act requires the listing of streams, rivers, lakes and estuaries that do not meet
water quality standards. States must submit a list of these "water quality limited" waters to the
Environmental Protection Agency (EPA) every two years. For the mixing zone strategy, waters targeted
for the phaseout will focus on those waters listed as impaired for chemical contaminants or PoBTs.

Areas of Emphasis:

These are tidal rivers of the Chesapeake Bay where available ambient data indicate that there is a
significant potential for a chemical contaminant related problem within the river segment. This
designation is based on the report: Targeting Toxics: A Characterization Report - A Tool forDirecting
Management & Monitoring Actions in the Chesapeake Bay's Tidal Rivers. The report can be read at
http://www.chesapeakebay.net/pubs/792.pdf

Areas under finfish or shellfish advisories:

Waterbodies established by States where the analysis of fish, crab and shellfish data has identified where
contaminants pose a health concern to humans consuming them. The state then establishes consumption
advisories for those contaminants to protect human health. For the mixing zone strategy, only areas
under advisories for chemical contaminants will be considered in the priority area designation.

Businesses for the Bay:

A voluntary team of forward-looking businesses, industries, government facilities and other
organizations within the Chesapeake Bay watershed committed to implementing pollution prevention in
daily operations and reducing the releases of chemical contaminants, nutrients, and other wastes.

Chesapeake 2000 Agreement:

A voluntary agreement that will guide the next decade of restoration in the Chesapeake Bay watershed.
Signed by the Executive Council - Maryland Governor Parris N. Glendening; Pennsylvania Governor
Thomas J. Ridge; Virginia Governor James S. Gilmore, III; District of Columbia Mayor Anthony A.
Williams; U.S. Environmental Protection Agency Administrator Carol M. Browner; and Chesapeake
Bay Commission, Bill Boiling.

Chesapeake Bay Program:

The Chesapeake Bay Program is the unique regional partnership that's been directing and conducting the
restoration of the Chesapeake Bay since the signing of the historic 1983 Chesapeake Bay Agreement.
The Chesapeake Bay Program partners include the states of Maryland, Pennsylvania and Virginia; the
District of Columbia; the Chesapeake Bay Commission, a tri-state legislative body; the Environmental
Protection Agency, representing the federal government; and participating advisory groups.

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Chesapeake Bay Watershed:

The 64,000 square miles of land drained by the hundreds of thousands of rivers, creeks and streams
crisscrossing parts of New York, Pennsylvania, West Virginia, Delaware, Maryland, and Virginia and
the entire District of Columbia.

End of the pipe:

The point where the effluent from a point source enters the receiving water body. This is normally
defined in a NPDES permit.

Fact sheet:

A document which explains the background of a subject.

Industry compliance policies:

A policy set by the company, facility, or point source which outlines the philosophical attitude towards
meeting environmental regulations. Compliance policies determine what actions are taken when
environmental violations occur.

Mixing zone:

A mixing zone is an area where pollutants from a point source's discharge pipe are mixed with receiving
waters to dilute the pollutant's concentration. Inside a mixing zone, discharges of the pollutant are
allowed to exceed the water quality limits set by a state. It is assumed that the brief exceedance of the
water quality standard will not significantly impact aquatic organisms. At the boundary of the mixing
zone, the concentration of the chemical must meet the water quality standard set for that particular body
of water.

Non-limited mixing zones:

A non-regulatory use, mainly for permitting decisions, when mixing of the point source discharge with
the receiving water is evaluated to either establish effluent limits or determine the reasonable potential
for effluent limits for persistent or bioaccumulative toxics.

Persistent or bioaccumulative toxics:

A specific list of chemical contaminants which exhibit the properties of 1) being persistent in the aquatic
environment and having the potential to cause toxic impacts (certain metals), 2) being bioaccumulative
to organisms in the aquatic environment and having the potential to cause toxic impacts, or 3) being
bioaccumulative and persistent in the aquatic environment while having the potential to cause toxic
impacts to living resources (e.g. mercury and polychlorinated biphenyls). For this strategy this list of
chemical contaminants will be dynamic depending on available data and science and will be the focus of
the voluntary mixing zone phaseout.

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Point sources:

A source of pollution that can be attributed to a specific physical location; an identifiable, end of pipe
"point". For this strategy, a point source shall be considered a publicly owned treatment work, an
industrial/commercial facility, or federal facility having an NPDES discharge permit to waters within the
Chesapeake Bay.

Pollution prevention:

An activity that reduces or eliminates pollution at the source rather than through control or treatment
technologies at the end of the pipe or stack. Pollution prevention (P2) promotes a whole facility,
multimedia (air, waste, and water) perspective in order to avoid the transfer of pollutants from one waste
stream to another.

Pollution Prevention and Point Source Workgroup:

A workgroup under the Toxics Subcommittee charged with implementing and coordinating the point
source commitments of the Toxics 2000 Strategy, including implementing the mixing zone strategy.

Regions of Concern:

In these tidal rivers, available ambient data indicate that there are probable chemical contaminant related
problems. This designation is based on the report: Targeting Toxics: A Characterization Report - A
Tool forDirecting Management & Monitoring Actions in the Chesapeake Bay's Tidal Rivers. The report
can be read at http://www.chesapeakebay.net/pubs/792.pdf

Risk:

The probability of injury, disease, or death from exposure to a chemical agent or a mixture of chemicals.
Toxics 2000 Strategy:

A Chesapeake Bay watershed strategy for chemical contaminant reduction, prevention and assessment.
The strategy outlines more specific actions to meet the Chesapeake 2000 Bay Agreement Commitments.

Toxics Subcommittee:

The Subcommittee is charged with implementing the Toxics 2000 strategy signed by the Chesapeake
Executive Council in December 2000. The Subcommittee is responsible for the interjurisdictional
design, coordination, and implementation of ongoing and future efforts to identify, assess and control
existing sources of chemical contaminants, better understand their impacts on the Bay's living resources
and human health, and prevent future sources of chemical contaminants from causing impacts on the
Chesapeake Bay system. The Toxics Subcommittee reports to the Implementation Committee of the
Bay Program.

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Voluntary means:

Actions not required by law, but go above and beyond the law. For the mixing zones strategy, all
pollution prevention/treatment technologies implemented or voluntary agreements signed to meet this
goal constitute a voluntary mean.

Water quality standard:

Guidelines developed to protect the most sensitive designated "beneficial use" of a waterbody, this can
be a numeric concentration of a pollutant in the water column. The Clean Water Act requires each state
to designate "beneficial uses" and develop water quality standards to protect them. These beneficial uses
include fisheries, aquatic life, wildlife, recreation, drinking water supplies, agriculture, irrigation,
hydroelectric power and aesthetics. Examples of water quality characteristics for which standards have
been set to protect beneficial uses include pH, dissolved oxygen, temperature, turbidity, bacteria and
toxics. Federal law requires protection of the most sensitive beneficial use in any river, stream or lake.

Zero release of chemical contaminants:

The concept of striving to achieve a no net release of chemical contaminants to the environment through
pollution prevention.

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