Breakout Session Notes
Estuary and Coastal Waters
Workshop on Water Quality Modeling for National-Scale
Economic Benefit Assessment
Washington DC, February 9-10, 2005

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DISCLAIMER
These proceedings have been prepared by Alpha-Gamma Technologies, Inc. under
Contract No. 68-W-01-055 by United States Environmental Protection Agency Office of
Water. These proceedings have been funded by the United States Environmental
Protection Agency. The contents of this document may not necessarily reflect the views
of the Agency and no official endorsement should be inferred.

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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
ESTUARY AND COASTAL WATERS
BREAKOUT GROUP NOTES
PARTICIPANTS
Aikman, Frank (National Oceanic and Atmospheric Administration)
Ali, Ghulum (US EPA, Office of Water)
Allen, Ashley (US EPA, Office of Water)
Besedin, Elena (Abt Associates, Inc.)
Cerco, Carl (US Army Corps of Engineers)
Dettmann, Edward (US EPA, Office of Research and Development)
Gross, Tom (National Oceanic and Atmospheric Administration)
Hayter, Earl (US EPA, Office of Research and Development)
Helm, Erik (US EPA, Office of Water)
Leeworthy, Bob (National Oceanic and Atmospheric Administration)
MacWilliams, Lauren (US EPA, Office of Water)
Parameswaran, Siva (Texas Tech University)
Pascual, Pasky (US EPA, Office of Research and Development)
Patchen, Richard (National Oceanic and Atmospheric Administration)
Powers, John (US EPA, Office of Water)
Sheng, Peter (University of Florida)
Slawecki, Theodore (Limno Tech, Inc.)
Swanson, Craig (Applied Science Associates, Inc.)
NOTE-TAKER
Peter von Loewe (Tetra Tech, Inc.)
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Estuary and Coastal Waters, Session 1
February 9, 1:00-3:30pm
Discussion Chairs: Carl Cerco (US Army Corps of Engineers)
Breakout Question
Scope out and characterize different approaches to modeling water quality in estuaries and
coastal waters for national scale benefit assessment (e.g., steady state, hydrodynamic, empirical,
probabilistic, etc.). What characteristics make these modeling approaches more or less suitable
for evaluating water quality benefits at a national scale? What are the capabilities and
limitations, advantages and disadvantages, or tradeoffs among the different water quality
modeling approaches? How would one go about developing each approach? How long should it
take and how much should it cost to develop each alternative? Rank order or rate the modeling
approaches in terms of their suitability for national-scale benefit assessment. Identify four off-
the-shelf models that EPA could use (e.g., modified tidal prism model, CE-QUAL-ICM). Rank
or rate these models in terms of in terms of their suitability for national-scale benefit assessment
Provide a rationale for each ranking or rating.
Discussion
To structure the discussion, Carl Cerco asked the participants to write down three modeling
approaches. Five minutes were allotted for this exercise, during which time the participants were
instructed to focus on approaches to modeling or modeling methodologies, rather than selecting
particular model codes.
Questions were raised (Richard Patchen and Craig Swanson) prior to the start of the exercise as
to what the "target" or "endpoint" should be for the modeling exercise.
Carl Cerco explained that the modeling approach should address the issue of modeling on a
national scale for economic benefit assessment, as described by the discussion topic for this
session.
After the 5 minutes had expired, Carl Cerco asked each of the participants what they had selected
as their 3 modeling approaches. There was some duplication of approaches selected (3D Time-
dependent, Box Model, and Data Assimilation), but 12 separate approaches were identified
during the exercise, as shown in the following table.

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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Approach
Votes
Steady State 2D, 3D Hydro and Groundwater
I
3D Time Dependent
III
Box Model/Tidal Prism
Nil
Ecosystem
I
Data Assimilation/Statistical/Regression/Neural Networking
III
Physical Model
I
Load Reduction Model (50% reduction = 50% improvement)
I
Sentinal Estuaries
I
Baysian
I
Community Based
I
4D Integrated Model
I
Near-field Mixing Model
I
Carl Cerco suggested adding a "comparative" model approach to the list of approaches, but
discussion was refocused and this approach was not added.
A dialog began to clarify the definition of some of the approaches (John Powers and Richard
Patchen) and whether some of the categories were redundant or inappropriate.
There was some discussion regarding some of the approaches as to whether or not these were
approaches or requirements. Those deemed as requirements, as opposed to approaches, were
separated out into a separate list below.
	Requirement
Good, Cheap, Easy	
Predictive of Swimability	
Predict Fish Habitat	
Considers Commercial Fishing	
Considers Aquaculture Additives	
Considers Fish Species	
Flexible	
Ability to Identify Uncertainty	
Based on the inventory of approaches and requirements, the discussion was turned (Theodore
Slawecki) to focus on the evaluation of national modeling approaches.
As a result, Carl Cerco asked the participants what national-scale pollutants would need to be
addressed in such a modeling system. The following list was produced.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Pollutants to be Considered
Pathogens	
Solids	
Metals	
Nutrients	
Drugs	
Organics	
Temperature	
Invasive Species	
Carl Cerco then asked what the time scale/time step would have to be to consider modeling these
pollutants and to obtain results useful in assessing economic benefits.
The group agreed that this would be a question for an economist rather than a water quality
modeler, and the question was posed to John Powers. John Powers' response was that the time
interval would depend on the pollutant and criteria for that pollutant.
There was some discussion regarding a daily time step (Earl Hayter) requirement for situations
where the majority of pollutant loading occurs during episodic high flow periods (i.e., Hg). The
discussion also considered using seasonal time steps for some pollutants (i.e., metals).
In a continuation of the discussion regarding requirements of economic modeling, Bob
Leeworthy described how NOAA looks at "place-based" economic models. He mentioned that
annual time scales work best for these, and had also looked at daily, weekly, and monthly time
scales.
Richard Patchen then asked John Powers, being an economist, whether a model producing output
at 30-second time steps would represent a non-attainment condition if one time step fell below
the criteria for a given pollutant.
John Powers responded that the economy field is still trying to figure this out, but that in that
case, frequency of non-attainment should be considered.
John Powers mentioned that it is unclear whether the water body must be "safe" or "attaining"
for all periods, or frequently.
Richard Patchen suggested that a 6-48 hour minimum time step be used to represent critical
episodic events.
Carl Cerco introduced another exercise for the group to investigate the preferences of the group.
The following chart was drawn on the board and the participants were asked which type of
modeling they would prefer with respect to modeling on a national scale.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Valuable
Less Valuable
Easy Hard
A discussion ensued regarding which types of models were included in each of the boxes. It was
decided that the valuable/easy category would include statistical and box models, and the
valuable/hard category would include 2D/3D hydrodynamic and groundwater and 4D integrated
models. Easy/less valuable models would be load reduction models. The votes were then
tallied:
Valuable
Less Valuable
4
CO


Easy Hard
In an effort to define which modeling methods are easy, hard, valuable, and less valuable, the
participants voted on the particular methods and where they thought they should be put in this
matrix. The following shows the results of the voting.
2

4
1

10


5

3
1
Steady-state
3-D
Box/Tidal Prism
1
9

1


12

7
1
3

Statistics
Load reduction
4-D integrated

10


Ecosystem
4
1
4

Mixing zone
Following the tally, Tom Gross questioned the ability of statistical models to forecast. He noted
that to do so, they would use extrapolation techniques that are unbound by physical or empirical
data when simulating conditions outside of observations. He mentioned that these are useful
when operating within conditions confined by observed values, but extrapolation may give
inappropriate results.
John Powers asked if physical models could extrapolate through time and space.
A number of responses were yes, including from Tom Gross, Carl Cerco, and Earl Hayter.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
A discussion comparing physical and statistical models ensued. Statistical models are not
confined by physics, and would be less appropriate for long-term simulations where the
likelihood of extreme conditions is greater.
Carl Cerco asked whether the easy/valuable models should be developed for application on a
national scale in the short term, and the hard/valuable models be developed over the long term.
The group thought that these types should be developed coincidentally and not staggered.
End of Breakout Group Discussion
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Estuary and Coastal Waters, Session 2
February 10, 8:30am-10:45am
Discussion Chairs: Gross, Tom (National Oceanic and Atmospheric Administration)
Breakout Question
Achieving a degree of spatial and temporal scale and resolution in water quality models that is
consistent with national-scale economic benefit assessment needs has been recognized as an
issue in past benefit assessments.
o How are different scales and resolutions more or less appropriate for different types of
benefits and different approaches to benefit assessment?
o Finer resolution in model outputs is generally obtained by increasing the precision, and
resolution of model inputs. However, accurate specification of the input variables in large-
scale model applications has been a problem in the past because of data limitations and
inconsistencies in the resolution of input variable databases. How could the choice of a
modeling approach or a model address this problem?
o Would EPA be doing itself a disservice by using a model intended to achieve relatively high
levels of precision without sufficient knowledge about the inputs of a site being modeled to
achieve that level of precision?
o Refer to the alternative modeling approaches you characterized in Breakout Session 1. Rank
order or rate these modeling approaches in terms of their ability to achieve both the spatial
and temporal scale and resolution needed for national scale benefit assessment. Provide a
rationale for each ranking or rating.
Discussion
To structure the discussion, Tom Gross asked the participants to write down three national-scale
indices of water quality. Five minutes were allotted for this exercise. The following table was
developed based on the responses of the participants.
Initially, the indices were listed, but the group felt that some of the indices should be separated
into two groups: Services and products of nature.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Indices
Services(Q s) \Properties of Nature (X,)


Diversity

X
Biomass

X
Positive Recreational Use
X

Aquatic Health
X

Bacterial Contamination
X
X
Turbidity

X
Sediment Alteration

X
Woody Debris

X
Sediment Transport and Potable Water
X

Fish Safety Consumption
X

DO

X
Algal Concentrations/ HAB

X
Navigable Waters
X

SAV

X
Sustainability
X

Aesthetics
X

Good Flushing

X
Nutrient Flux

X
Fishable
X

Swimmable
X

Boatable
X

Potable
X

John Powers suggested use of the following formula to determine the utility of a given index:
U= U(Qs(Xi))
where U is utility, Qs is the designated use/service, and X is a property of nature.
os=n x,wi
1
where W is the index.
Discussion ensued (Bob Leeworthy, Tom Gross, and John Powers) regarding willingness to pay
(WTP) approaches, and whether economic models exist to calculate the public's WTP.
John Powers responded that there are economic models to do so.
Tom Gross felt the need to group the indices into coarse service (Qs) groups for further
discussion. The groups chosen were fish safety, aquatic health, recreational use, and human
health.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Tom Gross asked the group for their thoughts on which properties of nature (Xi) were
applicable to maintaining each of the services, and for the time scale or time step each would
require for national scale modeling purposes. The table below was developed based on group
responses.
Properties of Nature (X,)
DO
Turbidity
Mixing
Nutrients
;Sediment Transport
Algal Blooms
; Bacterial Contamination
Temperature/ Salinity
; Ecosystem Webs/Biodiversity ;
Biomass
Pathogens
Coarse Q s Groups
Coresponding X,
Required Time Scale
Fish Safety
Bioaccumulation (toxins)
Seasonal, regional

Bioaccumulation (pathogens)
episodic (daily, hourly)

DO
Patchy
Aquatic Health
DO
Seasonal, regional

Turbidity
episodic (daily, hourly)

Flushing, mixing
Patchy
Recreational Use
Pathogens
Seasonal, regional

Algal Productivity
episodic (daily, hourly)


Patchy
Human Health
Risk Assessment
Seasonal, regional

pathogens, toxics
episodic (daily, hourly)


Patchy
Richard Patchen asked if higher resolution is worth it with respect to economic benefit analyses.
General discussion concluded that for a large range of time scales, it is important, depending on
the particular index and property of nature. Shorter time scales would be useful in simulating
discrete periods where criteria are being exceeded, while longer time scales would be useful for
forecasting. It was concluded that forecasting for risk probability assessment would require full
resolution.
John Powers explained that high temporal resolution is valuable because a WTP value can be
derived for a change in the number of days of beach closures, for example.
Theodore Slawecki noted that statistical models cannot predict beach closures for a specific day
because they are probabilistic in nature.
Tom Gross mentioned that Hindcasting or probabilistic studies for a 10-year period, for example,
have value to build a likelihood of closures per year.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Craig Swanson suggested that a database of likelihoods could be developed for beach closures
base on existing data.
Richard Patchen mentioned that he could never see not needing fine time scale models with
predictive capability.
Carl Cerco thought that a box-type model would potentially be a good candidate for Hg in
sediment, and possibly better than a 3D hydrodynamic model, as data availability is not available
for that system. This is commonly a limiting factor for model resolution.
Discussion ensued regarding conversion or communication of model results from one type of
model to another. Someone noted that the coarsening of a 3D model to a box model is relatively
easy, while the conversion of a box model to a 3D model is not possible. It was noted that
computer power is cheap and to keep the technology curve in mind. Computer power is likely to
get even cheaper.
Peter Sheng discussed the concept of Grid computing and the Integrative modeling paradigm
where computer resources are exploited to their max to enable researchers to connect and use a
full suite of models for most any application. There remains little reason to not do the fully
resolved model anymore.
Discussion occurred regarding the need for collaboration of research labs and the development of
new paradigms for modeling on a large scale.
End of Breakout Group Discussion
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
Estuary and Coastal Waters, Session 3
February 10, l:00pm-3:30pm
Discussion Chairs: Cerco, Carl (US Army Corps of Engineers)
Breakout Question
What modeling and benefit assessment issues should EPA be thinking about as it develops a
strategic development plan for water quality models that could be used in national scale benefit
assessment in estuaries and coastal waters?
Discussion
To structure the discussion, Carl Cerco asked the participants to write down five properties of the
"ideal model." Five minutes were allotted for this exercise.
There was a general discussion following this request regarding the system and pollutants being
modeled, and the temporal and spatial scale of the model.
Carl Cerco responded that the characteristics should describe a model designed to consider
economic benefits and water quality at a national scale.
Following the five allotted minutes, the following list of characteristics was produced.
Interactive: 5 properties of an ideal model
Transparent and documented	
Calculates uncertainty	
Adaptable	
Spatially-explicit to about 1km2	
Multiple pollutants	
Scalable to National/Regional	
Multi-dimensional	
Coupled to hydro, watershed	
Pre and post-processor	
Verifiable	
Universal	
Answers management questions	
Fast	
Self-calibrating	
Scalable in Space and Time	
Flexible in Formulation, Endpoints and Modules
Can be run by a non-modeler	
Useful in Forecasting	
Doesn't take a lot of Data, and data is available
Clearly-defined inputs	
Carl Cerco then asked the group about what would be needed to develop the "ideal" model.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
A large list of needs was produced and summarized into the following categories.
¦	Money
¦	People
¦	Data
¦	Objectives
¦	Buy-in
¦	Time
¦	Framework
Carl Cerco asked the group to lump the remaining responses on a group by group basis. The first
group to be discussed was the "Framework" group.
Richard Patchen asked whether the components of the framework could be hypothetical or if
they had to currently exist in order to add them to the list.
Carl Cerco responded that he would add components that currently do not exist and make note
that they do not. The list of "Framework" components is shown below, with a "?" designating a
component that does not exist or exists but is not satisfactory.
¦	Good Theory
¦	Flydro model
¦	Atmospheric Deposition
¦	Eutrophication
¦	Sediment Transport
¦	Ecological Model?
¦	Pollutant Transport and Fate
¦	Watershed
¦	Processors?
¦	Endpoints?
¦	Economic Model
¦	Linkage?
Richard Patchen asked John Powers about the types of economic models that are available today,
and if they are as rigorous as the water quality models.

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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
John Powers responded that economic models exist, but are not process based and as rigorous as
the water quality models, but he thought that existing models could be adapted.
¦	Observations (Temporal, Spatial)
¦	Forcing Functions
¦	Socioeconomic Data
¦	Description of Domain
¦	Health Criteria
Carl Cerco then asked the group to list the types of data required for the "ideal" model. The
responses are listed below.
Carl Cerco then asked the group to list the types of people or staff required for the "ideal" model.
The responses are listed below.
¦	Programmers
¦	Information Technology
¦	Biologists
¦	Hydrologists
¦	Multidisciplinary Scientists
¦	Economists
¦	Managers
¦	Leaders
Carl Cerco asked the group if these personnel are in supply in the workforce.
The group thought that all were available, but some more than others, and that some require a
higher pay scale than others.
Carl Cerco began to ask the group about the pay scales for each position, but dismissed that
exercise.
Carl Cerco noted that programmers are a necessity in most advanced modeling projects, but are a
"dime a dozen."
Richard Patchen noted that although programmers are an important component, a programmer
with an environmental or economic background would be preferable, since based on his


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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
experience, many programmers are not familiar with water quality processes and don't have the
ability to QA/QC model code.
The group agreed that multidisciplinary scientists familiar with hydrology and ecology and who
also program would be key personnel.
Theodore Slawecki suggested that a leader would have to be driven and interactive in the
process, rather than a macro-manager. He thought someone with Bill Gates' abilities would be
appropriate for the role as leader.
¦	Political Savvy
¦	EPA, NOAA, USACE, etc..
¦	Scientific Community
¦	Regulated Population
¦	International
Carl Cerco asked the group what would be needed for buy-in.
The group acknowledged that each of the buy-in components would be required except for the
international component. This component would be more of a supplement for instilling buy-in
for the remaining stakeholders.
Carl Cerco asked the group what would be needed for time-accelerators. The following list was
developed.
¦	<10 Years
¦	Immediate Prototype for Buy-in (2 Years)
¦	Training, Communication
¦	Identify Parallel Tasks
¦	Economic, Engineer Linkage
¦	Deadline
¦	What's Different
¦	Environmental Endpoint
¦	Public Well-being
¦	Multiple User
¦	Economy of Scale
Tom Gross thought that a prototype for buy-in would be one of the more important components
on the list.
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Breakout Session Notes, Estuary and Coastal Waters
February 10, 2005
The group, in general, agreed that the economic-engineer linkage is a vital component that would
need to be established early on to promote progress on the system.
Carl Cerco asked the group what would be needed in terms of money to develop the "ideal"
modeling system. The following list was developed.
¦	Prototype
¦	First Shot
¦	Great Job
$1,000,000
$500,000
$10,000,000
End of Breakout Group Discussion
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