South Puget Sound Model Nutrient Study
Entry ID: wa_de_spasm

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Summary
Abstract: Ecology's Southwest Regional Office (SWRO) is concerned about nonpoint
and point source nutrient loading to the southern portion of Puget
Sound (located south of The Narrows near Tacoma). Their major concern
is that the past and future growth around this region may cause
adverse effects on water quality due to increased eutrophication. The
SWRO requested that the Environmental Investigations and Laboratory
Services (EILS) Program evaluate the ability of the South Sound to
assimilate nutrients, and if needed, recommend point source waste load
allocations (WLAs) and nonpoint source load allocations (LAs) for
controlling nutrients.

Excessive nutrient inputs can accelerate the eutrophication process
and affect water quality in the following ways: 1) increase the growth
of algae and cause shifts in community structure, leading to the
predominance of undesirable forms (e.g., toxic phytoplankton blooms);
2) alter the balance between phytoplankton, zooplankton, fish and
shellfish that may result in an unusually high accumulation rate of
organic matter on bottom sediments, which may depress bottom oxygen
concentrations; 3) change the aerobic bacteria populations to
anaerobic sulfate-reducing bacteria, that can poison the water column
with hydrogen sulfide, which may lead to further community structure
changes; and 4) affect recreational activities due to objectionable
odors, and unsightly algal mats.

The capacity of South Sound to assimilate pollutants from its drainage
basins is presently not well understood. The major goal of this
project is to develop a computer model that can be used to simulate
hydrodynamics and water quality, characterize and evaluate pollutant
loading, and identify specific point and nonpoint sources of
pollutants to South Sound. If needed, another goal of the project will
be to establish a total maximum daily load (TMDL) for waterbodies not
meeting standards. The TMDL will be used to regulate pollutant loads
and establish appropriate point source wasteload allocations (WLAs),
and nonpoint source load allocations (LAs).

Technical Approach Section 303(d) of the Clean Water Act, requires
states to develop TMDLs for their waterbodies that are not meeting
their designated uses under technology-based pollutant
controls. However, Ecology has not adopted nutrient criteria or
recommended procedures for protecting waterbodies from excessive
nutrient loading. Since no site-specific or numeric nutrient criteria
exist for the Puget Sound, criteria must be developed to protect the
designated uses and water quality standards. For the South Sound, EILS
is proposing to develop site-specific nutrient criteria based on
linking measured nutrient concentrations (or loads) and an endpoint
indicator--i.e., dissolved oxygen concentrations.

The marine water quality standards for dissolved oxygen vary according
to the classification of a waterbody. The waterbody Classes AA, A, and
B are required to have dissolved oxygen concentrations which exceed
7.0, 6.0, and 5.0 mg/L, respectively, to meet state standards. In
addition, the following applies to all of the Classes: "When natural
conditions, such as upwelling, occur, causing the dissolved oxygen to
be depressed near or below the criterion, natural dissolved oxygen
levels may be degraded by up to 0.2 mg/L by human-caused activities."
This last condition is likely to be the endpoint indicator to link
changes in nutrient concentrations (loading) to water quality
violations which may occur in South Sound. The reason the South Sound
is considered a good candidate for linking the effects of nutrients to
dissolved oxygen concentrations and the allowable 0.2 mg/L degradation
is because many of the bays and inlets in the region have periods
(primarily in late summer) when oxygen concentrations drop below the
criteria.

The natural dissolved oxygen concentrations in many of the South Sound
waters are sometimes lower than the criteria because upwelled Pacific
Ocean water flowing into the Puget Sound can have naturally low
dissolved oxygen. Newton et al., (1997) assessed dissolved oxygen
concentrations in Puget Sound and suggested that bottom dissolved
oxygen concentrations can be exacerbated in areas that have strong
density stratification (e.g., in areas with freshwater input), high
production due to inhibited mixing, and oxidation of sunken organic
material (i.e., dead phytoplankton.). Eutrophication will likely have
the greatest impact in South Sound areas where flushing is low, where
strong density stratification occurs, and where phytoplankton growth
may be nutrient limited, such as in bays and inlets.

The following factors control nutrient enrichment, eutrophication, and
oxygen depletion: (1) nutrient loading rates from atmospheric
deposition, tributary inflows, point source discharges, nonpoint
source inputs (shorelands), and sediment-water exchange; (2)
hydrodynamic characteristics such as tides, stratification, mixing,
and freshwater inflow; and (3) photosynthetic characteristics and
processes such as light availability (season, depth), temperature,
growth, death, respiration, settling, and other phytoplankton
kinetics.

In order to determine the nutrient concentration that can be
assimilated into the South Sound without causing violations of the
endpoint target, EILS is proposing to model the waterbody. Model
predictions will be used to establish the nutrient criteria by
simulating estimated critical conditions and nutrient loading based on
past, present, and future water quality scenarios.

The central issues in calibrating the hydrodynamic or circulation
model of the South Sound will be simulating the tides, currents, and
salinity gradients. The pattern and motion of water in the South Sound
influences the distribution of dissolved oxygen. For example,
stratification established by light, fresh water inputs, and salty
Pacific Ocean water inflows may limit the vertical exchange of
dissolved oxygen and increase oxygen depletion in the bottom
waters. Although much more complicated, the circulation may also
affect algal productivity and the ultimate deposition and
decomposition of the organic mater produced from algal blooms.

The central issues in calibrating the water quality model will be
simulating the primary production by algae, decomposition of oxygen
containing material, and the concentration of dissolved
oxygen. Understanding the planktonic organisms, the effects of
nutrient enrichment, and the rates and pathways of organic matter
production and decomposition will determine the precision and accuracy
of the model to predict dissolved oxygen concentrations.

In order to predict circulation and water quality with the EFDC model
the suite of variables listed below will have to be determined by
using a combination of historical and newly collected data.

Circulation/Transport

Stage (tide gauge data)
Current (velocity and direction)
Salinity
Suspended Solids
Tributary freshwater inflows
Precipitation
Wind (speed and direction)
Atmospheric pressure/relative humidity/cloud cover
Temperature (water and air)

Eutrophication/Dissolved Oxygen

Salinity
Suspended solids
Dissolved oxygen
Nitrate-nitrite-N
Total kjeldahl-N
Total phosphorus
Primary Production
Metals (iron, manganese)
Silica
Zooplankton
Temperature
Biochemical Oxygen Demand (CBOD/NBOD)
Total and dissolved organic carbon
Ammonium-N
Ortho-phosphate
Solar Radiation
Light Extinction
Algal Composition/Biomass (diatoms, dinoflagellates, cyanobacteria,
greens)
Chlorophyll a/phaeopigments
Tributary Loads (nutrients, BOD)

Sediment

Sedimentation Rate (lead 210/sediment cores)
Sediment Oxygen Demand
Resuspension Rates (percent solids, silica)
Particulate Flux (nutrient transport and cycling, pigment transport
and distribution)

Information was obtained from
"http://www.ecy.wa.gov/ecyhome.html".

Related URL
Link: VIEW EXTENDED METADATA
Description: Metadata in Biological Data Profile format.


Geographic Coverage
 N: 49.39 S: 45.15  E: -116.53  W: -125.15

Data Set Citation
Dataset Originator/Creator: Washington State Department of Ecology
Dataset Title: South Puget Sound Model Nutrient Study
Dataset Release Place: Olympia, Washington
Dataset Publisher: Washington State Department of Ecology
Online Resource: http://www.ecy.wa.gov/ecyhome.html


Temporal Coverage
Start Date: 1998-01-01


Location Keywords
OCEAN > PACIFIC OCEAN > Puget Sound


Science Keywords
ATMOSPHERE >ATMOSPHERIC WATER VAPOR >HUMIDITY    [Definition]
ATMOSPHERE >ATMOSPHERIC WATER VAPOR >WATER VAPOR    [Definition]
ATMOSPHERE >ATMOSPHERIC WINDS >CONVERGENCE/DIVERGENCE    [Definition]
ATMOSPHERE >PRECIPITATION >PRECIPITATION AMOUNT    [Definition]
BIOSPHERE >VEGETATION >NUTRIENTS    [Definition]
HUMAN DIMENSIONS >ENVIRONMENTAL IMPACTS >CONTAMINANT LEVELS/SPILLS    [Definition]
TERRESTRIAL HYDROSPHERE >SURFACE WATER >STAGE HEIGHT    [Definition]
TERRESTRIAL HYDROSPHERE >WATER QUALITY/WATER CHEMISTRY >SUSPENDED SOLIDS    [Definition]
OCEANS >OCEAN CHEMISTRY >DISSOLVED GASES >DISSOLVED OXYGEN    [Definition]
OCEANS >OCEAN CHEMISTRY >NITROGEN >TOTAL NITROGEN    [Definition]
OCEANS >OCEAN CHEMISTRY >NUTRIENTS    [Definition]
OCEANS >OCEAN CHEMISTRY >PH    [Definition]
ATMOSPHERE >ATMOSPHERIC PRESSURE    [Definition]


ISO Topic Category
BIOTA
CLIMATOLOGY/METEOROLOGY/ATMOSPHERE


Quality
In order to improve the usefulness of the South Puget Sound Nutrient
Study results and focus the planning process, a Quality Assurance
Project Plan (QAPP) will be completed in FY99 (see Project Schedule).
EILS guidelines and specifications for preparing a QAPP will be
followed (Ecology, 1991). At a minimum, the QAPP will contain a
review of the following elements:

1. Project description
2. Project objectives and goals
3. Study design
4. Data analysis and modeling
5. Project schedule and laboratory budget
6. Project organization
7. Data quality objectives and analytical procedures
8. Sampling procedures

The QAPP will discuss the data needed to calibrate and confirm the
EFDC model, and establish nutrient loading to the modeled area. The
QAPP will also discuss in more detail how the model will be used to
determine the potential to violate water quality criteria, and
recommend waste load allocations (WLAs) for point sources and load
allocations (LAs) for nonpoint sources of nutrients. However,
developing a rough calibrated EFDC model (using historical data) of
the South Sound will be pursued in parallel with preparing the QAPP.

An important part of defining the data quality objectives for this
project will be to identify what decisions and actions might be taken
based on the proposed study. Ecology's regional office watershed
managers (see Project Organization) will need to develop decision
statements for addressing the results of the study. The decision
statements should address what decisions and actions Ecology will make
if specific parts of South Sound are estimated to have increased algal
growth and reduced dissolved oxygen concentrations because of human
caused contributions of nutrients. EPA (1997) has identified the
following specific activities for developing decision statements:

Define the alternative actions that could result from resolution of
the principal study question.

Combine the principal study question and the alternative actions into
a decision statement.

If applicable, organize multiple decisions to be made by priority.


Access Constraints
None


Use Constraints
None


Keywords
fecal coliform
dissolved oxygen
total nitrogen
pH
toxic substances


Data Set Progress
IN WORK


Data Center
Department of Ecology, Washington State    [Information]
Data Center URL: http://www.ecy.wa.gov/

Data Center Personnel
Name: GREGORY PELLETIER
Phone: 360.407.6485
Fax: 360.407.6884
Email: gpel461 at ecy.wa.gov
Contact Address:
Washington State Department of Ecology
Environmental Investigations and Laboratory Services Program
Watershed Assessments Section
Post Office Box 47600
City: Olympia
Province or State: Washington
Postal Code: 98504-7600
Country: USA


Personnel
ROBERT CUSIMANO
Role: TECHNICAL CONTACT
Phone: (360) 407-6000
Email: bcus461 at ecy.wa.gov
Contact Address:
Washington State Department of Ecology
Environmental Investigations and Laboratory Services Program
P.O. Box 47710
City: Olympia
Province or State: WA
Postal Code: 98504-7710
Country: USA


TYLER B. STEVENS
Role: DIF AUTHOR
Phone: (301) 614-6898
Fax: 301-614-5268
Email: Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA



Creation and Review Dates
DIF Creation Date: 2002-07-30
Last DIF Revision Date: 2012-12-12
Future DIF Review Date: 2003-07-30

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