f^CPjfy	EPA/600/F-16/060
www.epa.gov/ord
U.S. ENVIRONMENTAL PROTECTION AGENCY	INFORMATION SHEET
OFFICE OF RESEARCH AND DEVELOPMENT
National Health and Environmental Effects Research Laboratory
Atlantic Ecology Division, Narragansett Rl 02882
NARRAGANSETT-3VS MODEL OVERVIEW
In an effort to advance sustainability, EPA
Region 1 (New England) and the EPA Office of
Research and Development (ORD) are
collaborating on a project to address the
problem of nutrient impairment to ecological
functions in sensitive waterways. The project is
based on the Triple Value (3V) framework, an
innovative approach that captures the dynamic
interrelationships among economic,
environmental, and social systems.
Economy	Society
Sustainability
Environment
This approach is being piloted in the
Narragansett Bay watershed with the
development of a policy simulation tool that
draws from watershed-specific data and
stakeholder input. The model, entitled
Narragansett-3VS (Triple Value Simulation)
enables users to explore different scenarios,
interpret results, and evaluate outcomes of
selected policies or interventions aimed at
reducing adverse impacts of nutrients on the
watershed. The model is based on an
integrated assessment methodology called
System Dynamics and is intended to serve as a
communication tool that can help build shared
understanding of policy alternatives among
diverse groups including technical experts,
policy makers, and citizens. The model is not
intended to support specific permitting
decisions or individual site constraints; rather,
the goal is to create scenarios that launch
strategic dialogue about alternative water
resource management policies. The 3V
framework is transferable to other locations
and to other issues.
The model schematic on page 3 illustrates the 3V framework of economy, environment, and society,
including the primary variables included in the Narragansett-3VS model, as well as key relationships
among them. The schematic shows the indicators and relationships included in the model (solid lines),
as well as additional ones that have been identified as important elements of the system that the
model represents, but which could not be included quantitatively in the model (dashed lines). Black
lines indicate amplifying causal relationships while red lines indicate diminishing causal relationships.
Interventions are represented by green circles and are situated on the targeted causal relationships.
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The main elements of the schematic can be grouped into loadings (boxes with arrows pointing toward
the grey box labeled "Flows of water, nutrients, pathogens via land, groundwater, surface water"),
environmental relationships (boxes and arrows in the "Environment" section of the schematic), and
impacts on economy and society (all other boxes and arrows). The model currently focuses on
nitrogen (N) as the key nutrient.
An outline of the scenario setting options and a list of the key output indicators available for the
Narragansett-3VS model are provided below. Additionally, innovative interventions such as N recovery
and reuse, and new employment sectors, can be considered in future scenarios.
OPTIONS AVAILABLE FOR SETTING SCENARIOS
1)	Specify the interventions: Methods used to reduce nitrogen loadings or to increase nitrogen
removal for Narragansett Bay include specified reductions from:
•	Upgrades to Wastewater Treatment Facilities (WWTFs).
•	Upgrades to Onsite Wastewater Treatment Systems (OWTSs).
•	Reductions in nitrogen loading from animal waste.
•	Reductions in nitrogen loading from agricultural fertilizer.
•	Reductions in nitrogen loading from residential lawn fertilizer.
•	Reductions in atmospheric deposition of nitrogen.
•	Nitrogen reduction in the water body through removal by aquaculture farms.
•	Reductions in nitrogen loadings from surface water runoff through use of Low Impact
Development/Green Infrastructure (LID/GI) to reduce effective impervious area.
2)	Specify the magnitude of change for each intervention: Magnitude of change expressed as a
percent (e.g., 40% reduction in N loading, or 10 % reduction in impervious area).
3)	Specify the timing of impact for each intervention: Year at which change is achieved, can include
interim targets (e.g., 5% reduction by 2020 and 20% reduction by 2030).
4)	Specify the geographic location of impact for the interventions:
•	WWTF reductions, LID/GI, and residential fertilizer reductions can be specified by region of
the watershed.
•	The number of aquaculture farms can be specified by location within the Bay.
•	All other interventions affect the entire watershed.
5)	Specify cost of nitrogen reduction for each intervention:
•	Capital costs, including the costs of financing capital investments.
•	Ongoing costs: dollars per kg of N reduced.
6)	Specify financing options for each intervention:
•	Specify percent of cost publicly financed (as opposed to borne by citizens).
•	Specify interest rate and financing period for publicly financed interventions.
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SCHEMATIC OF ECONOMIC, SOCIAL, AND ENVIRONMENTAL VARIABLES AND RELATIONSHIPS IN THE NARRAGANSETT - 3VS MODEL
£
§
O
u>
Society
Economy
Watershed
population
Economic
development
Impervious
surfaces
\ Disposable
income
Municipal tax
revenue
Water use
Fishing &
tourism
Energy
use
Wastewater
treatment
Stormwater
runoff/
flood risk
Lawn
fertilizer
^ Beach
visits
Agriculture
& livestock
Atmospheric
deposition
Property
values
Flows of water, nutrients, pathogens
via land, groundwater, surface water
Forest
loss
Climate
change
¦ Pathogen
I loadings
Fresh water
loadings
Nitrogen
loadings
Phosphorus
loadings
Legend N
¦ | Sustainabiiity
_ Indicators
Amplifies
Diminishes
_>. Qualitative
Ulva growth
rate
Risk of hypoxia
& fish kills
Micro algal
blooms (Chi A)
Interventions
Precipitation
episodes
Air emission red
Fertilizer red
Aquaculture
WWTF treat
CSO tunnels
LID and Gl @
ISDS/septic upgrade
Water
clarity
Environment

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KEY OUTPUT INDICATORS
INDICATOR
UNITS
Scale
Economic/Social Indicators
Total and per capita cost of N reduction
dollars/year
Varies by Intervention
Total and per capita private N reduction costs
dollars/year
Varies by Intervention
Total public N reduction costs
dollars/year
Varies by Intervention
Total cost as percent of disposable income
%
Varies by Intervention
Commercial finfish landings
dollars
Whole Bay
Aquaculture revenue
dollars
Whole Watershed
Employment in aquaculture
jobs
Disaggregated
Beach visits
# of visits
Disaggregated
Value of beach visits
dollars
Disaggregated
Property value change
dollars
Disaggregated
Change in municipal tax revenue
dollars
Whole Watershed
Environmental Indicators
Total Nitrogen loadings
kg/year
Disaggregated
Nitrogen loadings by source category
kg/year
Disaggregated
Nitrogen concentration
mg/L
Disaggregated
Chlorophyll a
ug/L
Disaggregated
Water turbidity / clarity (secchi depth)
meters
Disaggregated
Ulva Growth Rate
%/day
Disaggregated
Eelgrass Improvement Potential
Unitless
Disaggregated
Hypoxia Risk
Unitless
Disaggregated
Due to data limitations, the model does not currently include several indicators that are considered
important elements of the system affected by nitrogen pollution in Narragansett Bay (or by policy
alternatives aimed at reducing nitrogen loadings). These indicators include dissolved oxygen, loadings
of other pollutants (e.g., pathogens, phosphorus, metals, and sediment), access to water, recreational
fishing and boating, aesthetics, human health, and flood risk.
QUALITY ASSURANCE
The Narragansett-3VS model was developed using quality assurance practices mandated by the EPA
and implemented by EPA ORD and our contractor. The model and documentation are currently
undergoing peer review.
CONTACTS FOR INFORMATION
The pilot study involved EPA's Office of Research and Development, EPA Region 1, and contractual
work with Industrial Economics, Inc. Inquiries may be directed to Dr. Marilyn ten Brink, (401-782-3078,
tenbrink.marilyn@epa.gov), Dr. Hal Walker (401-782- 3134, walker.henry@epa.gov) or Dr. Gary Foley
(919-541-0711, foley.garv@epa.gov) in the EPA Office of Research and Development, or to Johanna
Hunter (617-918-1041, hunter.johanna@epa.gov) in the EPA Region 1 Office of Ecosystem Protection.
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