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Title
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Eng
Effect of Winter Storm on Water Quality and Fish Toxicity: The Duwamish and Nisqually Rivers
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Date
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2007
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Creator
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Eng
Ubilava, Miriam
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Subject
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Eng
Environmental Studies
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extracted text
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EFFECT OF WINTER STORM ON WATER QUALITY AND FISH
TOXICITY
THE DUWAMISH AND NISQUALLY RIVERS
by
Mariam Ubilava
A Thesis: Essay of Distinction
Submitted in partial fulfillment
Of the requirements for the degree
Master of Environmental Studies
The Evergreen State College
June 2007
i
This Thesis for the Master of Environmental Studies Degree
by
Mariam Ubilava
has been approved for
The Evergreen State College
by
____________________
Maria Bastaki, PhD.
Member of the Faculty
____________________
Date
ii
TABLE OF CONTENTS
TITLE PAGE……………………………..………………………………….
iii
APPROVAL PAGE ………………………………………………………….
iv
TABLE OF CONTENTS ………………………………...………………….
v
LIST OF FIGURES …………………………………………………………. vi
LIST OF TABLES …………………………………………………………… vii
ACKNOWLEDGEMENT ……………………………………………………. viii
Chapter I. INTRODUCTION ………………………………………………. 1
I. a. The Duwamish River, Geography and History ……....… 3
I. b. The Nisqually River, Geography and History………….. 7
Chapter II. WASHINGTON STATE WATER QUALITY STANDARDS. 11
II. a Dissolved Oxygen ………………………………….………
II. b. Water Temperature …………………………….………...
II. c. Water pH Level ...…………………………….……………
II. d. Fecal Coliform Bacteria ...……………….……………….
II. e. Water Turbidity ...…………………………….…………...
II. f. Nitrate, Nitrite and Nitrogen .……………….…………….
II. g. Metals: Dissolved Copper and Lead ...………….………
12
15
17
19
21
22
24
Chapter III. METHODOLOGY ……………………………….……………. 25
III. a. Data sources ……………….………………..……………
III.a.a. Water quality data..……………………..…………..….
III. a. b. Precipitation data ……………………..………..…….
III.b. Data Analysis ……………………………….…………….
25
25
26
29
iii
TABLE OF CONTENTS (continued)
Chapter IV. RESULTS ……………………………………..……………. 31
IV. a. FC Bacteria ……………………………….…………….. 35
IV. b. Ammonia Nitrogen .………………………………..……. 38
IV. c. Nitrate-Nitrite Nitrogen ..………………………….……. 39
IV. d. Dissolved Oxygen ...…………………………….…….. 41
IV. e. pH level ..…………….……………………………..…… 43
IV. f. Water Temperature ....……………………………..…… .45
IV. g. Water Turbidity .…………..…………………………..…. 46
IV. h. Dissolved Copper and Dissolved Lead .…………….... 48
IV. i. Comparing the Duwamish River Urban Runoff
to the Nisqually River Non-urban Runoff .…………….. 53
Chapter V. DISCUSSIONS ..………...…………………………….…….. 57
Chapter VI. CONCLUSSIONS AND RECOMMENDATIONS ..…….… 64
VII. LITERATURE CITED …………………………………. .……………. 67
iv
LIST OF FIGURES
Figure 1. Precipitation Data at Tukwila and Panter Creek
Gauges (2002-2006) ………………………………………..…. 27
Figure 2. Precipitation data at the Panter Crek Gauge for
the Duwamish River (1990-2006) …………………………...
34
Figure 3. Precipitation data at the Panter Crek Gauge for the
Nisqually River (1988-2006) …………….…………………….
34
Figure 4. Number of Fecal Coliform Bacteria in the Duwamish
river at Tukwila in Winter and In Summer (1990-2006) ……
36
Figure 5. Number of Fecal Coliform Bacteria in the Nisqually
river at Nisqually in Winter and In Summer (1979-2006)…..
37
Figure 6. Concentration of Ammonia Nitrogen in the Duwamish
river at Tukwila in Winter and In Summer (1990-2006) ……
38
Figure 7. Concentration of Ammonia Nitrogen in the Nisqually
river at Nisqually in Winter and In Summer (1979-2006)….
39
Figure 8. Concentration of Nitrate-Nitrite Nitrogen in the
Duwamish river at Tukwila in Winter and In Summer
(1990-2006) ……………………………………………………..
40
Figure 9. Concentration of Ammonia Nitrogen in the
Nisqually river at Nisqually in Winter and In Summer
(1979-2006) …………………………………………………..…… 41
Figure 10. Dissolved Oxygen Level in the Duwamish river
at Tukwila in Winter and In Summer (1990-2006) ……….… 42
Figure 11. Dissolved Oxygen Level Figure in the Nisqually river at
Nisqually in Winter and In Summer (1979-2006) ………..…. 43
Figure 12. pH Level in the Duwamish river at Tukwila in Winter
and In Summer (1990-2006) …………………………..…..…. 44
Figure 13. pH Level in the Nisqually river at Nisqually in Winter
and In Summer (1979-2006) ……………………..…………… 44
Figure 14. Water Temperature in the Duwamish river at Tukwila
in Winter and In Summer (1990-2006) …………….………. . 45
v
LIST OF FIGURES (continued)
Figure 15. Water Temperature in the Nisqually river at Nisqually
in Winter and In Summer (1979-2006) ……………..……….. 46
Figure 16. Water Turbidity in the Duwamish river at Tukwila in
Winter and In Summer (1990-2006) ……………….………… 47
Figure 17. Water Turbidity in the Nisqually river at Nisqually in
Winter and In Summer (1979-2006) ……………………….. 48
Figure 18. FC Bacteria in the Duwamish and Nisqually Rivers
(1990-2006) …………………………………………………… 53
Figure 19. Ammonia Nitrogen in the Duwamish and Nisqually
Rivers (1990-2006) …………………………………………… 54
.
Figure 20. Nitrate-Nitrite Nitrogen in the Duwamish and
Nisqually Rivers (1990-2006) ……………………………….. 54
Figure 21. Dissolved Oxygen Level in the Duwamish and
Nisqually Rivers ………………………………………………. 55
vi
LIST OF TABLES
Table 1. Aquatic Life Dissolved Oxygen Criteria in Fresh Water ……… 12
Table 2. Aquatic Life Temperature Criteria in Fresh Water ………...…. 14
Table 3. Aquatic Life pH Criteria in Fresh Water ....……………..….….. 16
Table 4. Water Contact Recreation Bacteria Criteria in Fresh
Water …………………………………………………………..…. 17
Table 5. Aquatic Life Turbidity Criteria in Fresh Water .......……..……. 19
Table 6. Concentration of Dissolved Copper and Lead in the
Duwamish River …………………………………………..….. 21
Table 7. Concentration of Dissolved Copper and Lead in the
Nisqually River ………………………………………….….…... 21
Table 8. Differences in water quality parameters between
summer and winter: paired T-tests for the Duwamish
and Nisqually Rivers ……………..……………………………. 29
Table 9. Equations for Calculating Chronic and Acute Criteria for
Copper and Lead ………………………………………….……. 45
Table 10. Water Quality Criteria of Dissolved Copper and Lead
in the Duwamish River at Tukwila ………………..……..….. 46
Table 11. Water Quality Criteria of Dissolved Copper and Lead
in the Nisqually River at Nisqually ……………………..…… 47
Table 13. Statistical Values of T-Test, Comparing the Duwamish and
Nisqually Rivers Water pollutant and Quality Parameters …. 51
vii
ACKNOWLEDGMENTS
My deepest appreciation is extended to my adviser, Maria Bastaki,
for her greatest support, guidance and valuable suggestions, which were
very helpful for developing this research.
I would like to thank Dylan Monahan, Chad Brown and Brandon
Slone for providing me with data and necessary information to complete
this thesis.
I would like to thank my parents, Lali Zautashvili and Rezo Ubilava
for all of their support and efforts, which made me a person such as I am
now.
I would like to thank my brother, David, for his critical comments,
advises and support during the whole life and especially during the last
two years.
I would like to thank all MES faculty members and my friends, who
made my stay at Evergreen and in Olympia pleasant and hence my
academic and social life enjoyable.
I would like to express my big appreciation to the Edmund Muskie
Fellowship Program for providing me with the financial assistance to study
in the United States.
viii
ABSTRACT
Effect of Winter Storms on Water Quality and Fish Toxicity
The Duwamish and Nisqually Rivers
Mariam Ubilava
The Duwamish river receives urban runoff, while the Nisqually river
receives agricultural runoff. The Duwamish watershed has diverse
industrial activities, which increase pollution level in the river and has
impact on water quality parameters. Agricultural farms and lands around
the Nisqually watershed increase pollution of river basin from agricultural
activities and facilities. Fecal coliform bacteria, ammonia nitrogen, nitratenitrite nitrogen, water temperature, dissolved oxygen, water turbidity, pH
level and heavy metals (dissolved copper and lead) were analyzed, in
order to see health risk to fish in these river basins – specifically in
salmon. The Washington State Department of Ecology monitors the
Duwamish river site at Tukwila since 1990 and the Nisqually river site at
Nisqually since 1978. There were some days when water quality
parameters (fecal coliform bacteria and water temperature) exceeded
water quality criteria and could cause fish toxicity. The research shows
that pollution level is greater in winter than in summer, due to stormwater
runoff in both rivers, and the Duwamish river is more polluted than
Nisqually river, presumable because of the urban runoff in the Duwamish
watershed. The Department of Ecology, Department of Transportation and
other state and local agencies are working on reducing pollution level in
the Duwamish and Nisqually rivers, in order to protect fish wildlife and
biodiversity.
ix
Chapter I
INTRODUCTION
This thesis analyzes and compares water quality parameters and
chemical concentrations in the Duwamish river at Tukwila (water sample
station 09A0701) and Nisqually river at Nisqually (water sample station
11A0802) during the winter and summer seasons. The two rivers are
located in the same geographic area of Northwestern United States, in
Washington State, but the Duwamish River has an urban runoff, while the
Nisqually River has a non-urban runoff.
The drainage area for the Duwamish river at water resources
inventory resources area (WRIA) #9 is approximately 372,358 acres,
which is located in King County. The watershed is divided in upper and
lower parts. The upper part is mountainous, while the lower one is part of
the Puget lowlands. The main land uses of the Duwamish watershed are
forestry (58%) and urban (18%) related uses. (Ecology, 2006, WRI #9).
The main species that inhabit this river basin are salmonids (Chinook,
coho and chum), steelhead trout and shellfish. (Green-Duwamish
Watershed, Initial Assessment, 1995)
1
2
Water resources inventory area 09
Water resources inventory area 11
1
The drainage area of the Nisqually river is approximately 491,258
acres. The land in the Nisqually basin is mainly forested (75%) and
includes some Agricultural use (5%). Salmonid and shellfish are the main
species that inhabit the Nisqually watershed
(http://www.ecy.wa.gov/pubs/0610039/11.pdf, 2007).
The water quality of the rivers depends on the type and the quantity
of runoff that in turn depend on land use and precipitation patterns. It is
expected that the higher the precipitation the higher the volume of runoff
to the river. Since precipitation follows seasonal patterns, it is also
expected that the amount of precipitation and therefore stormwater runoff
is greater during the winter in Washington state than in summer. Water
quality is critical for the successful spawning, rearing and migration of
salmons, salmonids and shellfish in the Duwamish and Nisqually rivers.
Washington State has set water quality standards for fresh water,
including rivers. At any time water quality parameters and chemical
concentrations in the Duwamish and Nisqually rivers should meet State
standards.
According to my hypothesis, stormwater runoff increases the
amount of chemicals, toxins and microbiological organisms in the river.
The northern Washington State has high level of storms during the winter
season. Rain storms increase the amount of stormwater runoff during the
winter season. According to this hypothesis, concentration of chemicals,
2
toxins and biological organisms in the Duwamish and Nisqually rivers
should be increased during the winter storms.
In order to see whether stormwater runoff increases water pollution, I
compare winter water quality parameters and chemical concentrations to
those of summer.
Water quality in the two rivers is evaluated qualitatively and quantitatively.
The types of pollutants are described and compared to test whether
pollution level of the Duwamish River during the winter is higher than in
summer. In addition, statistical tests (linear regression and t-pair test) are
performed to quantitatively compare the concentrations of the pollutants in
the two rivers and test whether urban runoff significantly affects water
pollution compared to non-urban runoff.
I. a. The Green-Duwamish River, Geography and History
Urbanization, industrialization and an agricultural development are
the main factors, affecting water quality. The Green Duwamish River is
one of the most polluted rivers in the Northern part of Washington State.
The main tributaries of the Green-Duwamish River are Black River,
Newakum Creek, Crisp Creek, Mill Creek, Springbrook Creek, Soos
Creek, Jenkins and Covington Creeks. The size of the Green River
watershed is 492 square miles, with 65 miles length from Elliot Bay to
3
Howard Handson Dam. Two dams have been built: Tacoma Water Supply
Division Dam in 1911 and Howard Hanson Dam in 1962. The salmon
species present in this river are Chinook, chum, coho, and winter
steelhead (http://dnr.metrokc.gov/wlr/watersheds/green.htm). The Green
river is divided in three parts: Upper Green river, Middle Green River and
Lower Green River. The lower Green River is the most polluted part of the
whole Green Duwamish River. It is the most urbanized and industrialized
region. The tributaries Auburn, Mill, Midway Creek and Mullen Slough are
contributing pollution in the Lower Green River. (Kraft T., 2004)
4
5
Pollution of this river basin has started from the 1890s, when the
City of Seattle began construction of sewage systems. The sewage
system and stormwater runoff were discharged into the Duwamish River,
Elliot Bay and Puget Sound (http://www.ldwg.org/history.htm). It is also
important to mention that construction of the port in Seattle in 1911
increased pollution level of the river basin. Increased concentration of
toxins in the river made the Washington State Pollution Control
Commission to publish reports in 1945 about the investigations of metals,
oils, sewage and industrial waste into the Green-Duwamish River.
In 2001 the U.S. Environmental Protection Agency (EPA) listed the
Lower Duwamish River in the federal Superfund site list (a list of the most
toxic contaminated sites in the country)
(http://www.duwamishcleanup.org/). According to Duwamish Cleanup
Coalition, Duwamish river crab and fish in 1998 had seven times more
cancer-causing chemicals than fish from clean site. Among the pollutants
found in salmon at the Duwamish river superfund site, there were PCBs,
heavy metals, pesticides, sewage, and other toxins. These pollutants
found in the Duwamish river increase risk of human health and well-being,
through consumption of food species from the river, as well as the health
of fish and wildlife (http://www.duwamishcleanup.org/index.php?page).
Pollution of the Duwamish River affects mainly local society, inhabitants
and tribes, in many levels. High level of toxicity in the fish and crabs
6
affects human health. At the same time it affects the development of the
economic sector. For local tribes fishing is a source of income. Minimizing
recreational and fishing activities influence on the local inhabitants
income. At the same time it is important to mention that there are several
of non-English speaking communities living and working around the lower
Duwamish river basin and close to the Port of Seattle. Low level of
information regarding to the Duwamish river pollution and effect on human
and environmental health, keeps them from effectively protecting
themselves and their families’ health, living and working environment.
The contributors and sources of pollution of Duwamish River are:
Boeing, the City of Seattle, King Country, and the Port of Seattle.
Stormwater runoff, which contributes heavy metals, oil and grease from
the streets, arsenic in cement materials, industrial and domestic waste
have a long-term effect on the river pollution
(http://www.duwamishcleanup.org/index.php?page=who_is_responsible).
I. b. The Nisqually River, Geography and History
Compared to the Duwamish River, the Nisqually River is one of the
most pristine rivers in the Washington State
(http://www.nisquallyriver.org). The Nisqually River has its source at the
Nisqually Glacier on Mount Rainier. It flows 78 miles through forests and
7
mountains. It flows through the Fort Lewis Military Reservation and the
Nisqually Indian Reservation and enters into the Puget Sound
(http://www.outstandingrivers.org/rivers/nisqually_river/).
8
9
The lower Nisqually River is a transport corridor for anadromous
salmonids and is a place for spawning for chum, chinook, coho and
steelhead habitats (Ecology, 2005).
10
Chapter II
WASHINGTON STATE WATER QUALITY STANDARDS
Pollution of water bodies derived from storm water is called nonpoint sources (NPS) pollution. Atmospheric deposition, sediment flow from
improperly managed construction sites, forest lands and eroding stream
banks in addition of the above are the sources of NPS pollution (Water
Quality Standards for Surface Waters of the State of Washington, 2006,
http://www.epa.gov/owow /nps/qa.html). According to “Water Quality
Standards for Surface Waters of the State of Washington” (WQSSWSW)
(2006) storm water is defined as “the portion of precipitation that does not
naturally percolate into the ground or evaporate, but flows via overland
flow, interflow, pipes, and other features of a storm water drainage system
into a defined surface water body, or a constructed infiltration facility”.
NPS pollution has a harmful effect on the ecosystem of the
Duwamish and Nisqually river basins. The purpose of the chapter 173201A WAC of WQSSWSW is to establish water quality standards for fecal
coliform bacteria, dissolved oxygen, water temperature, water pH level
and water turbidity for surface waters of Washington State consistent with
public health and protection of fish and wildlife. The surface waters are
11
protected by designated uses and criteria (Water Quality Standards for
Surface Waters of the State of Washington, 2006).
The following chapters include a qualitative and quantitative
analysis of water quality parameters such as water temperature, pH,
dissolved oxygen, turbidity, ammonia nitrogen, nitrate-nitrite nitrogen, fecal
coliform bacteria, and concentration of metals: dissolved copper and lead.
This chapter includes definitions of the abovementioned water quality
parameters, Washington State water quality standards, sampling
procedures and descriptions of their effects on water quality and fish.
The sampling procedure is determined by the Unites States
Environmental Protection Agency (EPA). Washington State Department of
Ecology samples Washington rivers monthly.
II. a Dissolved Oxygen
Dissolved Oxygen (DO) is oxygen dissolved in water. It is the
main source of oxygen for fish and aquatic life. Fish absorbs oxygen
directly from water through the gills. The sources of oxygen in water are:
wind and wave action, direct diffusion from the atmosphere and
photosynthesis. Photosynthesis is one of the most important sources of
oxygen in the aquatic environment. The level of oxygen during the night is
lower than during the day, which is explained by the absence of
photosynthesis during the night and the increasing respiration by fish and
12
plants (photosynthesis occurs, when sunlight shines on the plant in the
water, which is during the day time) (http://edis.ifas.ufl.edu).
The level of DO varies in response to changes of water
temperature and atmospheric pressure. The higher the water temperature
the lower is the solubility of oxygen in water. Oxygen depletion (lack of
oxygen in the water) can occur in every season. However, summer is the
season when oxygen depletion (OD) occurs more often than in any other
three seasons. Cool water is more capable to hold oxygen than warm
water. The water with 7ºC temperature can hold 11.9 mg/L DO, while
warmer water (32º C) can hold only 7.4 mg/L DO (WSWQS, 2006). In the
warm water, the metabolism in fish increases, which increases oxygen
demand as well. Another reason of high level of DO is atmospheric
pressure. The higher the atmospheric pressure the higher is concentration
of DO. Atmospheric pressure increases oxygen solubility in water. DO
level in the surface waters can be decreased with higher concentrations of
organic and inorganic materials, chemicals and toxins
(http://edis.ifas.ufl.edu).
DO level in the water determines aquatic life’s wellbeing. When
oxygen consumption exceeds oxygen production, oxygen depletion occurs
(http://edis.ifas.ufl.edu). Oxygen depletion (OD) may cause fish mortality.
According to 2006 Washington State Water Quality Standards, minimum
DO level in the surface waters should be in the range 6.5mg/L - 9.5 mg/L.
13
Fish mortality in surface waters occurs when the level of DO concentration
is less than 2mg/L. The larger the fish the more affected by low level of
DO it is than smaller ones. In the Duwamish and Nisqually rivers DO level
was never observed as low as 2mg/L.
The 1-Day minimum DO required for aquatic life categories depends
on the species and varies between 6.5mg/L to 9.5 mg/L (Table 1.)
Table 1. Aquatic Life Dissolved Oxygen Criteria in Fresh Water
Category
Lowest 1-Day Minimum
Char Spawning and rearing
9.5 mg/L
Core Summer Salmonid Habitat
9.5mg/L
Salmonid Spawning, Rearing, and
8.0mg/L
Migration
Salmonid Rearing and Migration Only
6.5 mg/L
Non-anadromous Interior Redband Trout
8.0 mg/L
Indigenous Warm Water Species
6.5 mg/L
Source: Water Quality Standards for Surface Waters of the State of Washington, 2006
DO sampling procedure. The water samples for determining DO
level in the water are taken in the thalweg (the middle part of the river,
channel) (Washington State Water Quality Standards, 2006).
14
II. b. Water Temperature
Water Temperature is another main water parameter, which
determines surface water quality level. Temperature is different between
lowland streams and mountain rivers. Lowland streams are warmer, while
mountain streams are cooler. High temperature can cause oxygen
depletion in river, which could be followed by fish mortality
(http://www.state.ky.us/nrepc/water/wcpno.htm).
The temperature in the surface water can be increased naturally
(increasing atmospheric temperature) and by humankind activities, by
increasing non-point source (NPS) pollution (Water Quality Standards for
Surface Waters of the State of Washington, 2006). High water
temperature affects fish embryos. Lethality of embryos can occur, when 1DMax3 temperature is greater than 17.5ºC. For adult salmons migration 1DMax temperature should not be greater than 22ºC (WQSSWSW, 2006).
Metabolic changes of biological communities in rivers and streams depend
on water temperature. Water discharge, depth, season, time of day,
stream segment, solar radiation and human activities determine water
3
"1-DMax" or "1-day maximum temperature" is the highest water temperature
reached on any given day. This measure can be obtained using calibrated
maximum/minimum thermometers or continuous monitoring probes having sampling
intervals of thirty minutes or less. (Stream Sampling Protocols for the Environmental
Monitoring and Trends Section, 2001)
15
temperature. Chapter 173-201A WAC of WQSSWSW (2006) sets a 7DADMax4 temperature, in order to protect fish and wildlife, and have
sufficient level of fish spawning, rearing and migration in the Washington
State rivers. The highest tolerated temperature is different for different
species (Table 2.).
Table 2. Aquatic Life Temperature Criteria in Fresh Water
Category
Highest 7-DADMax
Char Spawning
9ºC
Char Spawning and rearing
12ºC
Salmon and Trout Spawning
13ºC
Core Summer Salmonid Habitat
16ºC
Salmonid Spawning, Rearing, and
17.5ºC
Migration
Salmonid Rearing and Migration Only
17.5ºC
Non-anadromous Interior Redband Trout
18ºC
Indigenous Warm Water Species
20ºC
Source: Water Quality Standards for Surface Waters of the State of Washington, 2006
4
"7-DADMax" or "7-day average of the daily maximum temperatures" is the
arithmetic average of seven consecutive measures of daily maximum temperatures. The
7-DADMax for any individual day is calculated by averaging that day's daily maximum
temperature with the daily maximum temperatures of the three days prior and the three
days after that date. (Stream Sampling Protocols for the Environmental Monitoring and
Trends Section, 2001)
16
Sapling procedure for Temperature. The samples for determining
water temperature should be taken from the well mixed water in the rivers
and streams, and not from the shallow part of the surface water and not
from the edge of the river (WSWQS, 2006. (Stream Sampling Protocols
for the Environmental Monitoring and Trends Section, 2001)
II. c. Water pH Level
pH level measures hydrogen ion concentration in water. The
measure of the river water pH shows how acidic or basic the water is
(http://www.grc.nasa.gov/WWW/K-12/fenlewis/Waterquality.html). pH
changes in the river influences on water quality and water chemistry,
which has an effect on fish health (http://www.fishdoc.co.uk/water/pH.htm)
Water pH level ranges from 0 to 14. The highest pH unit is 14, which
means the water is highly basic (alkaline). The neutral level of pH is 7. The
lower the pH the higher the acidity, so the closer to 0 the pH is the more
acidic it is. The changes of each pH unit are changes in the hydrogen ion
concentration relative to the hydroxyl ion concentration: the more
hydrogen ions the more acidic and the more hydroxyl ions the more
alkaline or basic. High or low levels of pH makes river inhospitable for fish
and aquatic life. The pH level in the fresh water basins should be within
the neutral range from 6.5 to 8.5 for effective fish spawning and rearing
17
(Table 3.) (Stream Sampling Protocols for the Environmental Monitoring
and Trends Section, 2001).
Table 3. Aquatic Life pH Criteria in Fresh Water
Category
pH units
Char Spawning and rearing
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.2 units.
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.2 units.
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.5 units.
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.5 units.
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.5 units.
Between 6.5 and 8.5, with a humancaused variation within the above range of
less than 0.5 units.
Core Summer Salmonid Habitat
Salmonid Spawning, Rearing, and
Migration
Salmonid Rearing and Migration Only
Non-anadromous Interior Redband Trout
Indigenous Warm Water Species
Source: Water Quality Standards for Surface Waters of the State of Washington, 2006
Sapling procedure for pH. Water samples for pH are collected by
the DO sample bucket. The probe of the pH meter is placed in the water
sample. The measurements should be reported on the Field Data Report
Form (Stream Sampling Protocols for the Environmental Monitoring and
Trends Section, 2001).
18
II. d. Fecal Coliform Bacteria
Fecal Coliform (FC) bacteria refer to that portion of the coliform
group of bacteria which presents in the intestinal tracts and feces of warmblooded animals. FC bacteria grow on warm temperature and are
produced by the fecal material of warm-blooded animals. Bacteria occur in
the water through domestic sewage
(http://www.state.ky.us/nrepc/water/wcpfcol.htm).
In recreational and fresh waters, the FC bacteria must not exceed a
geometric mean5 value of 50 colonies/100 ml in the extraordinary primary
contact recreation (Table 5). While in the primary contact recreation
category, it must not exceed a geometric mean value of 100
colonies/100ml. For secondary contact recreation FC bacteria must not
exceed a geometric mean value of 200 colonies/100 mL, (Table 4) (Water
Quality Standards for Surface Waters of the State of Washington,
Washington State Department of Ecology, 2006).
"Geometric mean" means either the nth root of a product of n factors, or the
antilogarithm of the arithmetic mean of the logarithms of the individual sample values
5
19
Table 4. Water Contact Recreation Bacteria Criteria in Fresh Water
Category
Extraordinary
Primary Contact
Recreation
Primary Contact
Recreation
Secondary Contact
Recreation
Bacteria Indicator
Fecal coliform organism levels must not exceed
a geometric mean value of 50 colonies/100 mL,
with not more than 10 percent of all samples (or
any single sample when less than ten sample
points exist) obtained for calculating the
geometric mean value exceeding 100
colonies/100 mL.
Fecal coliform organism levels must not exceed
a geometric mean value of 100 colonies /100
mL, with not more than 10 percent of all samples
(or any single sample when less than ten
sample points exist) obtained for calculating the
geometric mean value exceeding 200 colonies
/100 mL.
Fecal coliform organism levels must not exceed
a geometric mean value of 200 colonies/100 mL,
with not more than 10 percent of all samples (or
any single sample when less than ten sample
points exist) obtained for calculating the
geometric mean value exceeding 400 colonies
/100 mL.
Source: Water Quality Standards for Surface Waters of the State of Washington, 2006
Sampling procedure for Fecal Coliform bacteria. The detection limit
of FCB is 1 colony per 100 mL water. A 250 mL autoclaved bacterial
sampler bottle and fecal coliform sampler is used to determine amount of
FCB. After collecting sample for FCB, the sample should be placed in the
cooler in ice and shipped to Lab for analysis (Stream Sampling Protocols
for the Environmental Monitoring and Trends Section, 2001).
20
II. e. Water Turbidity
Water Turbidity is another criterion of aquatic life, which is
measured in nephelometric turbidity units (NTUs). Turbidity is the amount
of particulate matter suspended in water. Suspended soils that cause
turbidity are: clay, silt, organic and inorganic matter, microscopic
organisms, plankton and soluble colored organic compounds. High level of
turbidity makes the water cloudy, which has a negative effect on fish
spawning and rearing. Turbidity measures the scattering effect that
suspended matter has on light. Rain storms and therefore storm water
runoff (particles from the land are washed into the river) increase water
turbidity in rivers (http://ga2.er.usgs.gov/bacteria/helpturbidity.cfm).
According to the Department of Ecology Water Quality Standards
for Surface Waters of Washington State 2006, turbidity level in fresh
waters should not exceed the background of 50 NTU by more than 5-10
NTU depending on the species (Table 5).
21
Table 5. Aquatic Life Turbidity Criteria in Fresh Water
Category
NTUs (turbidity should not
exceed)
Char Spawning and rearing
Core Summer Salmonid Habitat
Salmonid Spawning, Rearing, and
Migration
Salmonid Rearing and Migration
Only
Non-anadromous Interior Redband
Trout
Indigenous Warm Water Species
5 NTU over background when the
background is 50 NTU or less
5 NTU over background when the
background is 50 NTU or less
5 NTU over background when the
background is 50 NTU or less
10 NTU over background when the
background is 50 NTU or less
5 NTU over background when the
background is 50 NTU or less
10 NTU over background when the
background is 50 NTU or less
Source: Water Quality Standards for Surface Waters of the State of Washington, 2006
According to the chapter 173-201A-200 WAC of Water Quality
Standards for Surface Waters of the State of Washington (2006) turbidity
criteria can be modified after in-water constructions, which result in the
disturbance of in-place sediments.
II. f. Nitrate, Nitrite and Nitrogen
Nitrogen is one of the most widely distributed chemical elements in
the world. 80% of air contains nitrogen. Nitrogen can be organic and
inorganic. Inorganic nitrogen can exist as nitrate NO3-, nitrite NO2-,
ammonia NH3+ or molecular gas N2. The main sources of nitrogen in rivers
are septic tanks, municipal and industrial wastewater, animal waste and
car exhausts. Nitrites are easily converted to nitrates in water by bacteria.
22
Nitrates reduce DO level in rivers, which cause oxygen depletion. Nitrites
have effect on fish by developing “brown blood disease”
(http://www.state.ky.us/nrepc/water/wcpno.htm). Nitrite enters into the
fish’s bloodstream system through gills. Hemoglobin combines with nitrite
and forms methemoglobin. Methemoglobin blocks transportation of
oxygen in the blood and turns blood into chocolate-brown color. When
there is lack of oxygen in the body, fish starts gasping
(http://msucares.com/pubs/infosheets/is1390.htm). In humans, nitrates
also react with hemoglobin in blood cells and produce methemoglobin.
The “Blue baby” disease or methemoglobinemia is a serious disease in
babies, which is developed by producing methemoglobin. The nitrate level
above 0.5 mg/l, and nitrite and nitrogen levels above 90mg/l has toxic
effect on fish (http://www.state.ky.us/nrepc/water/wcpno.htm).
Nitrates in rivers occur through insufficiently and inefficiently treated
waste-waters, and ineffective filtration systems. Nitrite is broken down to
nitrate by bacteria. If nitrite production exceeds conversion of nitrite to
nitrate, fish in the river are at risk for brown blood disease
(http://msucares.com/pubs/infosheets/is1390.htm) .
Sampling procedure for Nutrients. Nutrients include nitrogen and
phosphorus. The detection limit for ammonia and nitrate-nitrite nitrogen is
0.01 mg/. After taking water sample, the bottle with water sample is
23
labeled, placed in the cooler and shipped to Lab (Stream Sampling
Protocols for the Environmental Monitoring and Trends Section, 2001).
II. g. Metals: Dissolved Copper and Lead
The concentration level of metals in the Duwamish river at 09A080
water sample station was sampled in 2002-2003 water years (Table 6) by
the Washington State department of Ecology. In the Nisqually river at
11A070 water sample station, metals were sampled in 1998-1999, 20012002 (Table 7) water sample years.
Table 6. Concentration of
Dissolved Copper and Lead
in the Duwamish River
Sampling
date
12/11/2002
Dissolved
Cu (ug/L)
1.11
Dissolved
Pb (ug/L)
0.244
2/24/2003
0.48
0.04
6/16/2003
0.43
0.036
8/18/2003
0.36
N/D*
Table 7. Concentration of
Dissolved Copper and Lead
in the Nisqually River
Sampling
date
Dissolved
Cu (ug/L)
12/13/1998
2.3
2/23/1999
1
Dissolved
Pb (ug/L)
0.1
0.06
N/D
6/28/1999
0.4
12/11/2001
1.1
0.05
N/D
2/19/2002
0.9
6/25/2002
0.4
N/D
N/D
8/27/2002
0.6
24
Chapter III
METHODOLOGY
III. a. Data sources
III.a.a Water quality data
The water quality monitoring data for this thesis were downloaded
from the Washington State Department of Ecology’s web-site:
http://www.ecy.wa.gov/apps/watersheds/riv/station.asp?theyear=&tab=fina
l_data&scrolly=174&sta=09A080&docextension=.xls&docextension=.xls
for the Duwamish river at Tukwila at 09A080 water sample station and
http://www.ecy.wa.gov/apps/watersheds/riv/station.asp?theyear=&tab=fina
l_data&scrolly=579&wria=11&sta=11A070 for the Nisqually river at
Nisqually at 11A070 water sample station in March, 2006.
The water quality monitoring data on the Duwamish river were
taken at Tukwila, at the 09A080 water sample station. The Duwamish river
at Tukwila is considered a class A water category (excellent water
category).
The Nisqually river water quality monitoring data were taken at Nisqually,
at the 11A070 water sample station. The Nisqually river is also classified
as water quality category A.
25
III. a. b.Precipitation data
Precipitation data for the Duwamish and Nisqually river basins, was
downloaded from King County’s web-site at
http://dnr.metrokc.gov/wlr/waterres/hydrology/DataReport.aspx , in April,
2007.
Precipitation data for the region were recorded at the Sea-Tac airport
precipitation monitoring station at the site Panther Creek precipitation
gauge, with a site code 03u. Precipitation records from the gauge at the
site Tukwila I&I Rain Gage with a site code TUKW would have been more
representative of the Duwamish river because this site is closer to water
sample station 09A080 than Panther Creek precipitation gauge. However,
the Tukwila I&I Rain Gage gauge was installed only in October 1st, 2002
and historical precipitation data from this station is only available since this
day http://dnr.metrokc.gov/wlr/waterres/hydrology/DataReport.aspx .
To avoid bias in precipitation data and to see whether they could be used
as a representative precipitation data for the Tukwila area, I compared
precipitation data at the site Panther Creek precipitation gauge to Tukwila
precipitation gauge for the period since October 2002 (the Tukwila gauge
was established in October 2002) (Figure 1).
26
precipitation (inches)
1.4
1.2
Tukwila Gauge
1
Panter Creek Gauge
0.8
0.6
0.4
0.2
0
9/20/2006
7/22/2006
5/23/2006
3/24/2006
1/23/2006
11/24/2005
9/25/2005
7/27/2005
5/28/2005
3/29/2005
1/28/2005
11/29/2004
9/30/2004
8/1/2004
6/2/2004
4/3/2004
2/3/2004
12/5/2003
10/6/2003
8/7/2003
6/8/2003
4/9/2003
2/8/2003
12/10/2002
10/11/2002
8/12/2002
6/13/2002
4/14/2002
2/13/2002
12/15/2001
10/16/2001
8/17/2001
6/18/2001
4/19/2001
years
Figure 1. Precipitation Data at Tukwila and Panter Creek Gauges (20012006). The precipitation data are taken in the same days when water was
sampled at the Duwamish River water sample station.
The precipitation data at the Tukwila site matches closely those at
the Panter creek site. In some cases there were small differences
observed. For example, in January 24, 2001 precipitation at Tukwila
Gauge was 0.06 inches, while at Panter Creek Gauge it was 0.12 inches.
Another small difference is recorded in August 22, 2001. Precipitation was
0.24 inches greater at Tukwila Gauge (1.25 inches) than in Panter Creek
gauge (1.04 inches). In January 27, 2003 there was difference in
precipitation between these two gauges, with a difference of 0.23 inches
(0.54 inches precipitation at Tuwkila gauge and 0.21 inches of
precipitation at Panter Creek gauge). Another big difference occurred in
December 13, 2004. Precipitation at Tukwila gauge was 0.42 inches, while
at Panter Creek was no precipitation. In February 14, 2005, 0.33 inches of
precipitation was recorded at Panter creek gauge, while there was no
27
precipitation at Tukwila gauge. More differences of precipitation between
these two gauges were observed in June 13, 2005 (difference 0.3 inches)
and in December 14, 2005 (0.09 inches of precipitation at Panter Creek
Gauge and no precipitation at Tukwila gauge). There were no more
significant differences in precipitation data between these two gauges.
Observation on precipitation data at Tukwila and Panter Creek gauges
shows that there are some small precipitation differences between these
two gauges, but not significant. Small difference in precipitation does not
affect the linear regression tests. Therefore the precipitation data obtained
from the Panther Creek gauge is a good approximation to precipitation at
the Tukwila area.
The water sample station 11A080 in the Nisqually river is located in
King county as well. There is no available long-term historical precipitation
record for this gauge. Because of that and because the 11A070 water
sample station and Panter Creek precipitation gauge are located in the
same county and are geographically in close proximity as it relates to
weather phenomena, I used the historical precipitation data from Panter
Creek as a surrogate for the precipitation at the Nisqually river. The Panter
Creek gauge started operating from 1988.
28
III.b. Data Analysis
Water sampling on the Tukwila station of the Duwamish river has
started since 1990 by the Washington State Department of Ecology. I
used water sample data from December 1990 to August 2006. To
compare the level of winter water quality criteria to summer, I calculated
averages of winter months (December, January and February) and
summer months (June, July, August) for water DO, pH, temperature,
turbidity, FC bacteria, ammonia nitrogen and nitrate-nitrite nitrogen.
The water quality monitoring data for the Duwamish river at Tukwila
had missing data for DO in July 2000 (was not sampled in this month). To
obtain an estimate for the missed data of DO, I calculated averages of DO
in months of July from 1991 to 2006 and put the received amount in July
2000.
I used water sample data from December 1977 to August 2006.
The water quality monitoring data for the Nisqually river had missing data
for turbidity in July and August 1985, and in August 1992, temperature in
January 1979, FC bacteria - in December 1990, August 1986 and June
1988, ammonia nitrogen in June 1988, and DO in January 1991 and
January 1995. To obtain an estimate of missing data I calculated averages
by months and plugged into the missed months.
To compare some of the Duwamish river water quality parameters
(FC bacteria, ammonia nitrogen, nitrate-nitrite nitrogen and DO) to the
29
same water quality parameters of the Nisqually river, these two rivers
were compared to each other (for each year) with paired t-test.
30
Chapter IV
RESULTS
To test the hypothesis that stormwater runoff increases pollution
level in the river I used linear regression and to test whether water quality
parameters are greater in winter than in summer, I used the paired t-test.
To compare the Duwamish water quality (for each year) to the Nisqually
water quality, I used the paired t-test.
To find whether stormwater runoff increases the number of Fecal
Coliform (FC) bacteria, I used linear regression, where precipitation was
the independent value and number of FC bacteria was the depended.
Linear regression on FC bacteria in the Duwamish river at water sample
station 09A080, shows that there is some but not highly significant
evidence (p= 0.04701, t=2.01, R2=0.041 with the slope b1=137) to infer
that increase in precipitation (that there is correlation between precipitation
and FC bacteria), increases the number of FC bacteria in the river basin.
Linear regression on FC bacteria for the Nisqually river at the water
sample station 11A070, shows that there is not enough statistical
evidence (p=0.453, t=0.753, R2= 0.005 with a slope b1=41) to infer that
there is correlation between precipitation and number of FC bacteria in the
Nisqually river.
31
To compare other water quality parameters (ammonia nitrogen,
nitrate-nitrite nitrogen, DO, pH, temperature and turbidity) in the
Duwamish and Nisqually rivers between winter and summer, the
differences between the two seasons by years were examined with paired
t-tests.
These tests showed that there is significant evidence to infer that
the water quality parameters nitrate-nitrite nitrogen, DO, pH, turbidity are
greater in winter than in summer and that, as expected, water temperature
is lower in winter than in summer in the Duwamish river. However, there
was not significant evidence to infer that ammonia nitrogen levels are
greater in winter than in summer. In the Nisqually river, the tests showed
that there is significant evidence to infer that the water quality parameters
ammonia nitrogen, nitrate-nitrite nitrogen, DO, pH, turbidity are all greater
in winter than in summer and, as expected, water temperature is lower in
winter than in summer (Table 8).
32
Table 8.
Differences in water quality parameters between summer
and winter: paired T-tests for the Duwamish and Nisqually Rivers
The Duwamish River
The Nisqually River
t-stat
p-value
t-stat
p-value
FC Bacteria
0.402
0.3465
1.53
0.067
Ammonia nitrogen
-0.2284
0.4114
4.508
<0.001
Nitrate-nitrite
11.4636
<0.001
19.0631
<0.001
DO
23.4129
<0.001
28.2946
<0.001
pH Level
0.0292
-2.0474
<0.001
- 6.371
Water
<0.001
-38.669
<0.001
-6.446
0.001
3.57
0.005
2.697
nitrogen
Temperature
Turbidity
According to my hypothesis, high amount of precipitation in winter
increases the number of FC bacteria, ammonia nitrogen, nitrate-nitrite
nitrogen, pH, DO, water turbidity in the Duwamish and Nisqually rivers. In
the Washington state more rain storms are observed in winter than in
summer. Because of that, storm water runoff is greater in winter than in
summer. Precipitation during the water sampling days from 1990 to 2006
in the Duwamish river at Tukwila is approximately 5.68 inches and 2.08
inches in summer (Figure 2.). As for Nisqually river precipitation during the
winter from 1988 to 2006 totally was 6.64 inches and 3.03 inches in
summer (Figure 3).
33
inches
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Winter
Summer
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
yeards
Figure 2. Precipitation Data at The Panter Creek Gauge for the Duwamish
River (1990-2006). The data are given seasonally, sampled once in a
month.
This chart represents season total precipitation at the Panter Creek
Gauge (from 1990 to 2006) for those days when the water was sampled in
inches
the Duwamish river at Tukwila water sample station - 09A080.
1.2
1
0.8
0.6
0.4
0.2
0
Winter
Summer
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
Years
Figure 3. Precipitation Data at the Panter Creek Gauge for the Nisqually
River (19988-2006). The data are given seasonally, sampled once in a
month.
34
This chart represents precipitation data at the Panter Creek Gauge
(from 1988 to 2006) in the specific water sampling days in the Nisqually
river at Nisqually water sample station - 11A070.
IV. a. FC Bacteria
The linear Regression on FC bacteria in the Duwamish River at
09A080 (at Tukwila) water sample station shows that there is some but
not strong evidence to infer that number of FC bacteria increases with
increased precipitation in the Duwamish river basin at 09A080 water
sample station (slope=133.44, t = 2.0126, p= 0.04701, R²=0.041). Linear
regression on FC bacteria shows that there is correlation between
precipitation and FC bacteria in the Duwamish river. Paired t-test shows
that there is not enough evidence to infer that number of FC bacteria is
greater (Figure 4) in winter than in summer (t=0.4024, p=0.3465).
35
800
600
Winter
400
200
Summer
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
Number of FC Bacteria
1000
years
Figure 4. Number of Fecal Coliform Bacteria in the Duwamish River at
Tukwila in Winter and in Summer (1990-2006). Samples done once in a
month, three times in a season.
The highest amount of FC bacteria in the Duwamish river at
Tukwila water sample station was observed on the following 5 occasions.
The first three occurred on days with no precipitation: about 870 FC
bacteria /100ml on 2/20/1991; 470 FC bacteria/100ml on 12/19/1995; 490
FC Bacteria on 6/18/1997. The other two occurred on days of low
precipitation: on 1/20/1998 510 FC bacteria was counted in the water and
precipitation was 0.01 inches. On 8/22/01, 610 FC bacteria was detected
in water sample, with 1.04 inches of precipitation.
As for the Nisqually river, the linear Regression on FC bacteria at
11A070 (at Nisqually) water sample station shows that there is not enough
evidence to infer that number of FC bacteria increases by increasing
precipitation and stormwater runoff (slope=41.75, t =0.75, p=0.45,
R²=0.041 ). Linear regression on FC bacteria shows that precipitation and
therefore stormwater runoff does not increase amount of FC bacteria in
36
the river. In other words there is no significant linear relationship between
precipitation and FC bacteria in the Nisqually river.
The t-pair test on Fecal Coliform bacteria in the Nisqually River at
11A070 (at Nisqually) shows that number of FC bacteria is not significantly
greater (figure 5) in winter than in summer (t=1.539, p= 0.067) in the
1000
800
600
Winter
400
Summer
200
0
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
Number of FC Bacteria
Nisqually River basin at Nisqually water sample station.
years
Figure 5. Number of Fecal Coliform Bacteria in the Nisqually River at
Nisqually in Winter and in Summer (1979-2006). Samples done once in a
month, three times in a season.
The highest amount of FC bacteria in the Duwamish river at
Tukwila water sample station was observed in 12/20/1989 for about 1000
FC bacteria and with no precipitation in this day, 1/29/1992 with 590 FC
bacteria with a daily precipitation of 0.38 inches. Another high amount of
FC was recorded in 7/13/1983. There is no precipitation record for this
day.
37
IV. b. Ammonia Nitrogen
The paired t-test on Ammonia Nitrogen in the Duwamish River at
09A080 water sample station shows that there is not enough evidence to
infer that level of Ammonia Nitrogen in winter is greater than in summer
(Figure 6) in the Duwamish river basin at Tukwila water sample station (t =
-0.2284, p= 0.4112).
0.15
mg/L
0.12
0.09
Winter
0.06
Summer
0.03
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 6. Concentration of Ammonia Nitrogen in the Duwamish River at
Tukwila in Winter and n Summer (1990-2006). Samples done once in a
month, three times in a season.
The highest concentration levels of ammonia nitrogen in the
Duwamish river at 11A070 water sample station is observed in 12/19/1995
0.098mg/L with no precipitation in this day and 0.152 mg/L in 12/16/1997
with precipitation of 1.5 inches (Figure 2.)
The paired t-test on Ammonia Nitrogen in the Nisqually River at
11A070 at 09A080 water sample station shows that there is significant
evidence to infer that level of Ammonia Nitrogen in winter is greater than
38
in summer (Figure 7) in the Nisqually river basin at Nisqually water sample
station (t = 4.5088, p<0.001).
0.15
mg/L
0.12
0.09
Winter
0.06
Summer
0.03
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
years
Figure 7. Concentration of Ammonia Nitrogen in the Nisqually River at
Nisqually in Winter and n Summer (1979-2006). Samples done once in a
month, three times in a season.
The highest concentration levels of ammonia nitrogen in the
Nisqually river were 0.14 mg/L in 1/14/1982. There are no records for
precipitation on this exact day at Panter Creek gauge.
IV. c. Nitrate-Nitrite Nitrogen
The paired t-test on Nitrate-Nitrite-Nitrogen in the Duwamish River
at 09A080 water sample station shows that there is overwhelming
evidence to infer that level of Nitrate+Nitrite-Nitrogen in winter is greater
than in summer (Figure 8) in the Duwamish river basin at Tukwila water
sample station (t = 11.4636, p<0.001).
39
0.8
0.7
mg/L
0.6
0.5
0.4
winter
0.3
summer
0.2
0.1
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 8. Nitrate-Nitrite Nitrogen in the Duwamish River at Tukwila in
Winter and in Summer (1990-2006). Samples done once in a month, three
times in a season.
The highest concentration levels of Nitrate-Nitrite nitrogen in the
Duwamish river at Tukwila was observed in winter, 0.778 mg/L in
2/17/1999, with a precipitation of 0.09 inches in this day. 0.664mg/L of
Nitrate-nitrite nitrogen was observed in 1/19/200 and precipitation was
0.02 inches. 0.608 mg/L was in 1/24/2001 with precipitation of 0.12 inches
(Figure 2). There is an overall difference between winter and summer but
it is not directly related to precipitation level.
The paired t-test on Nitrate-Nitrite Nitrogen in the Nisqually River at
11A070 at 09A080 water sample station shows that there is significant
evidence to infer that level of Nitrate-Nitrite Nitrogen in winter is greater
than in summer (Figure 9) in the Nisqually river basin at Nisqually water
sample station (t = 19.0631, p<0.001).
40
mg/L
0.6
0.5
0.4
0.3
0.2
Winter
Summer
0.1
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
years
Figure 9. Nitrate-Nitrite Nitrogen in the Nisqually River at Nisqually in
Winter and in Summer (1986-2006). Samples done once in a month, three
times in a season.
The highest concentration levels of Nitrate-Nitrite nitrogen in the
Nisqually river at Nisqually was recorded in winter, 0.508 mg/L in
1/26/1993, with a precipitation of 0.12 inches in this day. 0.569mg/L of
Nitrate-nitrite nitrogen was recorded in 12/27/1996 with no precipitation in
this particular day. 0.515 mg/L was in 2/13/2006 with precipitation of 0.04
inches (Figure 3).
IV. d. Dissolved Oxygen
The paired t-test on DO in the Duwamish River at 09A080 water
sample station shows that there is overwhelming evidence to infer that
level of DO in winter is greater than in summer (Figure 10) in the
Duwamish river basin at Tukwila water sample station (t =23.4129,
p<0.001).
41
14
mg/L
12
10
winter
summer
8
6
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 10. Dissolved Oxygen Level in the Duwamish River at Tukwila in
Winter and in Summer (1990-2006). Sampled once in a month, three
times in a season.
The highest levels of DO were recorded in 12/12/1990 - 13.2 mg/L
and 13.19 mg/L in 2/24/2003. In these days water temperature were 6.1
°C and 4.7 °C.
The paired t-test on DO in the Nisqually River at 11A070 water
sample station shows that there is overwhelming evidence to infer that
level of DO in winter is greater than in summer (Figure 11) in the Nisqually
river basin at Nisqually water sample station (t = 18.2945, p<0.001).
42
mg/L
14
13
12
11
10
9
Winter
Summer
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
years
Figure 11. Dissolved Oxygen Level in the Nisqually River at Nisqually in
Winter and in Summer (1979-2006). Sampled once in a month, three
times in a season.
The highest levels of DO were recorded in 12/19/1990 – 14.1 mg/L,
13.4 mg/L –in 2/23/1993. In these days water temperature were 2.7 °C
and 3.8 °C.
IV. e. pH level
The paired t-test on pH in the Duwamish River at 09A080 water
sample station gives t = -2.0474, t value with a negative sign, and infers
that there is evidence to infer that pH level is greater in summer than in
winter (Figure 12) in the Duwamish river basin at Tukwila water sample
station (t =-2.0474, p = 0.0293).
43
8
pH
7.5
7
Winter
Summer
6.5
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 12. pH level in the Duwamish River at Tukwila in Winter and in
Summer (1990-2006). Sampled once in a month, three times in a season.
The paired t-test on pH in the Nisqually River at 11A070 at 09A080
water sample station shows that there is overwhelming statistical evidence
to infer that level of pH in winter is lower than in summer (Figure 13) in the
Nisqually river basin at Nisqually water sample station (t = -6.3716,
p<0.001).
8.5
pH
8
7.5
Winter
7
Sum mer
6.5
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
years
Figure 13. pH level in the Nisqually River at Nisqually in Winter and in
Summer (1979-2006). Sampled once in a month, three times in a season.
44
The higher pH levels were observed more in summer than in
winter. In 8/26/1987 pH level was 8.3, in 12/29/1987 - pH was 8.5 and in
6/29/1988 – 8.4.
IV. f. Water Temperature
The paired t-test on water temperature in the Duwamish River at
09A080 water sample station shows that there is overwhelming evidence
to infer that water temperature in summer is greater than in winter (Figure
14) in the Duwamish river basin at Tukwila water sample station (t =38.6691, p<0.001).
25
TEMP (C)
20
15
Winter
10
Summer
5
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 14. Water Temperature in the Duwamish River at Tukwila in Winter
and in Summer (1990-2006). Sampled once in a month, three times in a
season.
The temperature differences in winter and summer are mainly
explained by differences of air temperature in winter and summer.
45
The paired t-test on water temperature in the Nisqually River at
11A070 water sample station shows that there is overwhelming evidence
to infer that water temperature in winter is greater than in summer (Figure
15) in the Nisqually river basin at Nisqually water sample station (t = 6.446071884, p<0.001).
21
18
Temp (C)
15
12
Winter
Sum mer
9
6
3
0
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
years
Figure 15. Water Temperature in the Nisqually River at Nisqually in Winter
and in Summer (1978-2006). Sampled once in a month, three times in a
season.
IV. g. Water Turbidity
The paired t-test on water turbidity in the Duwamish River at
09A080 water sample station shows that there is significant evidence to
infer that water turbidity in winter is greater than in summer (Figure 16) in
the Duwamish river basin at Tukwila water sample station (t =3.5708, p =
0.00139).
46
Turbidity (NTU)
100
80
Winter
60
Summer
40
20
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 16. Water Turbidity in the Duwamish River at Tukwila in Winter and
in Summer (1990-2006). Sampled once in a month, three times in a
season.
As it is seen from figure 13, turbidity was greater in winter than in
summer. It reached its peak (94 NTU) in 2/20/1991, with no precipitation
on this or previous days. Higher level of turbidity in winter than in summer
is explained by greater water flow in winter than in summer, which is due
to more precipitation and storm water runoff in winter.
The paired t-test on water turbidity in the Nisqually River at 11A070
water sample station shows that there is significant evidence to infer that
water turbidity in winter is greater than in summer (Figure 17) in the
Nisqually river basin at Nisqually water sample station (t =2.6977, p =
0.0058).
47
Turbidity (NTU)
180
160
140
120
100
80
60
40
20
0
Winter
Summer
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
years
Figure 16. Water Turbidity in the Nisqually River at Nisqually in Winter and
in Summer (1978-2006). Sampled once in a month, three times in a
season.
As in the Duwamish river so in the Nisqually river higher level of
turbidity is observed in winter compare to summer (Figure 17). The
highest turbidity in the Nisqually river were 140 NTU 12/21/1994 with zero
precipitation in this specific day, 170 NTU 12/28/1998, no precipitation
was recorded in this day and 160 NTU 1/25/2005, with 0.07 inches of
precipitation,
IV. h. Dissolved Copper and Dissolved Lead
The Maximum Contaminant Level (MCL) of dissolved copper (Cu)
and lead (Pb) in the fresh waters is calculated by considering water
hardness (Table 9) (Ecology, Johnson A., 1994,
http://www.ecy.wa.gov/pubs/9458.pdf, Toxin Substances, WAC 173-201A240).
48
The criteria for dissolved Cu and Pb for the Washington state
waters is computed as a function of the relative water hardness. The
capacity of the water to bind elemenstal copper and transform to a less
toxic state to fish depends on water hardness. The higher hardness of the
water, the higher capacity of water to bind elemental copper.
(http://www.eho.wa.gov/searchdocuments/1997%20Archive/pchb%2096193%20summary%20judgment.htm ).
Table 9. Equations for Calculating Chronic and Acute Criteria for
Copper and Lead
Chronic Criteria
Acute Criteria
Source: Ecology, 1994, Johnson A.
In the Duwamish river at Tukwila, water sample station 09A080,
concentration level of metals were sampled four times during the 20022003 water year (twice in Winter 12/11/2002 and 2/24/2003, and twice in
summer 6/16/2003 and 8/18/2003) by the Washington State Department
of Ecology. The concentrations of dissolved copper in winter were
1.11ug/L and 0.48ug/L. The concentration levels of dissolved lead in
winter were 0.244ug/L and 0.04ug/L. In summer 2003 the concentrations
of dissolved copper were 0.43ug/L and 0.36ug/L. Dissolved lead in
49
summer (6/16/2003) were 0.036ug/L. In 8/18/2003 dissolved lead was not
determined. The hardness in winter was 48.4mg/L and 18.5mg/L, and
40.6mg/L and 49.3mg/L in summer. The table 10 summaries the water
quality criteria of dissolved copper and lead at given water hardness. The
values of dissolved copper and lead are within normal range.
Table 10. Water Quality Criteria of Dissolved Copper and Lead in the
Duwamish River at Tukwila
Hardness
Chroni
Acute
Concentratio
Chronic
Acute
Conc. of
mg/L
c
Toxicity
n of Dis. Cu
Tox. (Dis.
Tox.
Dis. Pb
Toxicit
(Dis. Cu)
(ug/L) in the
Pb)
(Dis. Pb)
(ug/L) in
y (Dis.
river
the river
Cu)
12/11/2002
48.4
5.48
7.7
1.11
6.3
22.3
0.244
2/24/2003
18.5
2.4
3.4
0.48
2.25
6.5
0.04
6/16/2003
40.6
4.7
6.5
0.43
0.69
17.8
0.036
8/18/2003
49.3
6.9
7.8
0.36
6.3
22.7
N/D*
In order to determine the metals criteria in the river, I used
equations given in the Table 2. Dissolved copper and lead at 48.4 mg/L,
18.5 mg/L, 40.6mg/L and 49.3 mg/L hardness should not exceed 5.48
ug/L, 2.4 ug/L, 4.7 ug/L, 6.9 ug/L, respectively, and for lead water quality
criteria at the same hardness is 6.3 ug/L, 2.25 ug/L, 0.69 ug/L and 22.7
ug/L, respectively. According to this calculation lead and copper did not
50
exceed water quality criteria in the Duwamish river at water sample
09A080 during the specific water sample days in 2002-2003.
The concentration levels of both metals, dissolved copper and
lead, in the Duwamish river, are greater in winter than in summer (Table
11), which is explained by increased urban runoff in winter than in
summer.
In the Nisqually river at the water sample station 11A070
concentration level of metals in the river were sampled in 1998-1999
(twice in winter and once in summer) and 2001-2002 (twice in winter and
twice in summer) water years. (Table 11).
Table 11. Water Quality Criteria of Dissolved Copper and Lead in the
Nisqually River at Nisqually
Date
Hardness
Chronic
Acute
Concentratio
Chronic
Acute
Conc. of
(mg/L)
Criteria
Criteria
n of Dis. Cu
Criteria
Criteria
Dis. Pb
(Dis.
(Dis.
(ug/L) in the
(Dis. Pb)
(Dis. Pb)
(ug/L) in
Cu)
Cu)
river
the river
0.1
12/13/1998
31
3.7
5.1
2.3
5.2
7.4
0.06
2.9
2/23/1999
23
6/28/1999
20
12/11/2001
23.9
2/19/2002
25.8
6/25/2002
24.4
3.05
24
3.01
4.46
3.8
1
3.4
0.4
3.96
1.1
4.26
0.9
4.04
0.4
4.6
0.6
4.56
6.69
N/D
6.1
4.11
6.34
0.05
5.16
4.6
6.78
N/D
3.2
4.7
6.97
N/D
6.83
N/D
8/27/2002
3.98
6.79
51
The metals criteria levels for the Nisqually river at 11A070 water
sample station were calculated by the same equations as for the
Duwamish river. The calculations show that dissolved copper and
dissolved lead, at 23.9 mg/L, 25.8 mg/L, 24.4mg/L, 24 mg/L, 31mg/L, 23
mg/L, and 20 mg/L hardness, should not exceed 3.7 ug/L, 2.9ug/L, 6.1
ug/L, 5.16 ug/L, 3.2 ug/L, 3.05 ug/L, 3.01 ug/L for dissolved copper, and
5.2 ug/L, 4.46 ug/L, 4.11 ug/L, 4.6 ug/L, 4.7 ug/L, 4.6 ug/L and 6.8 ug/L for
dissolved lead. The concentration of copper and lead in the Nisqually river
at 11A070 water sample station during the specific water sample days
meet water quality criteria.
Dissolved copper and lead in the Nisqually river in 1998-1999 and
2001-2002 winters are greater than in summer (Table 11) which is also
due to increased urban runoff in wet season (winter).
The negative health effect on fish from copper and lead would
occur when these metals did not meet water quality criteria. But there is
no evidence to infer that there was any ecological risk to fish in the
Duwamish and Nisqually rivers in the abovementioned water sample
years.
52
IV. i. Comparing the Duwamish River Urban Runoff to
the Nisqually River Non-urban Runoff
Urban runoff increases pollution of river basin more than non-urban
runoff. The Duwamish river, which has urban runoff, has more pollution
compared to the Nisqually river. Specifically Duwamish river shows higher
overall levels of FC bacteria (Figure 18), Ammonia Nitrogen (Figure 19),
Nitrate/Nitrite Nitrogen (Figure 20), and lower Dissolved Oxygen levels
Numver of FC Bacteria
(Figure 21).
1000
800
600
Duw amish
400
Nisqually
200
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
years
Figure 18. Comparing Number of FC Bacteria in the Duwamish river to the
Nisqually river. Sampled once in a month, three times in a season.
53
0.2
mg/L
0.15
Duwamish
Nisqually
0.1
0.05
0
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
sampling days
mg/L
Figure 19. Comparing Ammonia Nitrogen in the Duwamish river to the
Nisqually river. Sampled once in a month, three times in a season.
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Duwamish
Nisqually
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
sampling days
Figure 20. Comparing Nitrate-Nitrite Nitrogen in the Duwamish river to the
Nisqually river. Sampled once in a month, three times in a season.
54
14
mg/L
12
10
Duwamish
8
Nisqually
6
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
sampling days
Figure 21. Comparing Dissolved Oxygen Level in the Duwamish river to
the Nisqually river. Sampled once in a month, three times in a season.
Number of FC bacteria, ammonia nitrogen and nitrate-nitrite
nitrogen in the Duwamish river are significantly higher than in the
Nisqually river (for FC bacteria: t-value=0.05, p-values<0.002; ammonia
nitrogen: t-value=6.6, p-value<0.001; nitrate-nitrite nitrogen: t-value=15.67,
p-value<0.001; dissolved oxygen: t-value=-9.12, p-value<0.001). It was
expected that dissolved oxygen level would be greater in the Nisqually
river than in the Duwamish river (Table12), which is due to less urban
runoff. FC bacteria, ammonia nitrogen and nitrate-nitrite nitrogen has
effect on water quality parameters and therefore on DO level.
55
Table 12. Statistical Values of T-Test, Comparing the Duwamish and
Nisqually Rivers Water pollutant and Quality Parameters
t-value
p-value
mean
(Duwamish
river)±SD
mean
(Nisqually
river)±SD
FC Bacteria
5.05
<0.001
108±147.49
20±61.39
Ammonia Nitrogen
6.606
<0.001
0.03±0.02
0.014±0.009
Nitrate-Nitrite Nitrogen
15.67
<0.001
0.42±0.15
0.24±0.13
Dissolved Oxygen
-9.12
<0.001
10.43±1.53
11.29±0.99
56
Chapter V
DISCUSSIONS
According to Washington State Department of Ecology’s water
quality data, sampled from 1990 to 2006 in the Duwamish River at
Tukwila, 09A080 water sample station, the annual DO level ranges
between 7.6 mg/L and 13.2mg/L. DO level was never less than 7.5 mg/L
during the sampling from 1990 to 2006 water sampling years. In the
Nisqually River at 11A070 water sample station at Nisqually the annual
DO level is between 9.1 mg/L and 14.1 mg/L. DO level was never less
than 9.1 mg/L during the water sampling from 1977 to 2006. According to
these data DO levels in the Duwamish and Nisqually rivers are within the
range of Washington State water quality standards. There is no expected
negative effect on fish in these rivers.
The water temperature from 1991 to 2006 in the Duwamish River at
Tukwila is between 2.2 ºC and 6.8 ºC in winter and between 10.9 º C and
22.3 º C in summer. The water temperature exceeded water quality criteria
4 times in summer. In August 19, 1992, water temperature was 20.8 ºC, in
July 19, 1995 – 22.4 ºC, in July 21, 2003 – 22.3 º and August 15, 2005
was 20.4 º. In the Nisqually River at Nisqually water sample station the
57
water temperature in winter ranges between 3.2 ºC and 7.9 ºC. The range
of water temperature in summer is between 9.3 and 18.3 ºC. There are no
instances of exceeding the 7-DMax levels of temperature in the Nisqually
river. The calculation of average water temperature in the Nisqually river is
based on data collected from 1978 to 2006.
According to Bernhardt (1981) the upstream migration of Chinook
salmon and summer steal head is in summer (June, July and August).
Winter steelhead migrates upstream during the winter. Water temperature
in the Duwamish and Nisqually rivers in winter satisfies the migration pass
for summer steelheads and salmonids. The coho, chum and winter
steelhead start spawning in winter. According to WSWQS (2006) water
temperature in winter for spawning should be 9ºC-13ºC (depends on
species). The river basins water temperature does not exceed water
quality standard level for this activity. This means that water temperature
in the Duwamish and Nisqually rivers gives a sufficient spawning place to
coho, chum and winter steamheads. Summer Chinook rearing is in winter,
coho and winter steelhead is rearing during the whole year and summer
steelhead rearing is during the summer. According to WSWQS (2006) the
water temperature in summer should not exceed 17ºC for a productive
rearing. The Duwamish and Nisqually rivers satisfy Washington State
water quality standards. There were some days that water temperatures in
the Duwamish river were greater than acceptance level. Overall water
58
temperature is not expected to have negative effect on fish migration,
spawning and rearing in the Duwamish and Nisqually rivers.
High acidity or alkalinity has direct physical damage on fish skin,
gills and eyes. Prolonged toxicity and exposure to extreme pH levels
increase mucus production and epithelial hyperplasia (makes skin and gill
epithelia thicker), and cause stress in fish. Such kind of health problems in
fish can be followed by fish mortality. Fish maintains its own internal pH.
Extreme external (water) pH affects fish’s internal (blood) pH level, which
causes acidosis or alkalosis of the blood (too low and too high pH
respectively). Fluctuation of blood pH in fish can cause fish mortality in the
river basin. Several factors have an effect on pH level changes in river
(http://www.fishdoc.co.uk/water/pH.htm). Creating additional hydrogen or
hydroxyl ions, changes the pH level by added or dissolved compounds in
water. Cement and concrete make water more alkaline. Photosynthesis
plays one of the main roles in changing pH level. Plants and animals
respiration process excretes carbon dioxide in the water. By
photosynthesis, plants remove carbon dioxide and water becomes more
alkaline. The higher photosynthesis (more sunshine during the day and
algae in the water) the higher alkalinity of water is. According to these two
processes in the water, respiration and photosynthesis, the alkalinity and
acidity of water depends on day and night time cycle. During the day time
photosynthesis increases water alkalinity and during the night not having
photosynthesis and high respiration level increases acidity of water. High
59
level of pH increases the toxicity of some chemicals. The higher pH is the
more toxic ammonia is. Potassium permanganate is more toxic at high pH,
while chloramines-T is more dangerous at low pH
(http://www.fishdoc.co.uk/water/pH.htm).
The pH levels in the Duwamish river at Tukwila is between 6.8 and
7.6 and in the Nisqually river at Nisqually between 6.6 and 8.5. Compare
to Table 4, the pH levels of these river basins are sufficient for fish
spawning, rearing and migration.
Pollution level in rivers in winter is significantly greater than in
summer. Observations show that concentrations of copper and lead in the
Duwamish and Nisqually rivers are greater in winter than is summer. At
the same time water quality parameters: DO, turbidity, nitrate, nitritenitrate nitrogen and pH are greater in winter than in summer. The
observed concentrations of copper and lead are not expected to have
harmful effects on fish of these two rivers. The Duwamish and Nisqually
rivers are in the water class A (excellent water category). To consider
these rivers for class AA (extraordinary water category), more clean up
projects and TMDL studies should be implemented in these river basins.
The main pollutants for these basins are FC bacteria and ammonia
nitrogen. Water quality parameters (temperature and DO) did not meet
water quality standards several times during the specific water sample
days. In summer water temperature exceeded water quality criteria in
specific days in the Duwamish and Nisqually rivers.
60
The number of FC bacteria in the Duwamish River at 09A080 water
sample station did not meet secondary contact recreational water quality
criteria 13 times From these, the highest exceeding levels were observed
in February 1992, August 1994, December 1994, December 1995,
February 1996, June 1997, January 1998, August 2001 and December
2002. The highest amount of FC bacteria was 870/100ml–in February 20,
1991. In the Nisqually river at 11A070 water sample station the number of
FC bacteria did not meet secondary contact recreational water quality
criteria 4 times. In December 1981 the number of FC bacteria was
220/100ml, in July 1983 was 500/100ml, in December 1992 it was
1000/100ml and 590/100ml in January. High level of FC bacteria affects
water pH balance and depletes oxygen in the water. Sewage also
contains nitrogen and phosphorus, which in the rivers and surface waters
acts as a fertilizer for aquatic plants and algae. Therefore in addition to FC
bacteria sewage also increases photosynthesis during the day and leads
to depletion of oxygen during the night
(http://www.ecy.wa.gov/pubs/0210010.pdf).
The water turbidity in the Duwamish river at Tukwila exceeded
water quality criteria once in February 20, 1991 (94.5NTU) during the
whole 1990-2006 water sample years. In the Nisqually river water turbidity
did not meet water quality criteria 5 times during the water sampling 19782006 years. The highest number was 170 and 160 NTU, sampled in
December 28,1998 and January 25, 2005. In both of these rivers, high
61
numbers of water turbidity were sampled during the winter, which is
explained by more precipitation. Increasing water runoff into the rivers,
increases flow of clay, silt, organic and inorganic matters, microscopic
organisms, plankton and soluble colored organic compounds in the river.
The average amount of ammonia nitrogen and nitrate-nitrite
nitrogen in the Duwamish River at station 09A080 in winter is 0.03mg/L
and 0.54mg/L respectively, while in summer the average amount of
ammonia nitrogen and nitrite-nitrate nitrogen is 0.031mg/L and 0.307mg/L
respectively. In the Nisqually river at 11A070 water sample station
average amounts of ammonia nitrogen and nitrite-nitrate nitrogen in winter
is 0.02mg/L and 0.37mg/L vs. 0.01mg/L and 0.12mg/L in summer. The
higher concentration of nitrates in winter than in summer is explained by
agricultural runoff and increased amount of rain storm during the winter
season.
Nitrite is less toxic than ammonia. Nitrite level over 0.1mg/L in the
fresh water is considered as unacceptable, while nitrate level in the fresh
water should not exceed 50mg/L
(http://www.fishdoc.co.uk/water/nitrite.htm). Ammonia causes damage in
fish at level of 0.1mg/L. In higher alkalinity of water there is more ammonia
present, while at acidic level of pH more ammonium (NH4+) is present,
which is less toxic than ammonia. Ammonia more than 0.1mg/L in fresh
water causes the destruction of mucus membranes in the fish and
damages gills. At 0.1mg/L nitrite level symptoms of fish nitrite poisoning
62
includes gasping and fast gill movement. These symptoms occur during
the low level of DO as well. Higher level of nitrite can be followed by fish
mortality and brown blood disease in fish. Nitrate is less harmless to fish
than both nitrite and ammonia
(http://www.thetropicaltank.co.uk/cycling2.htm). High level of nitrate might
have long-term effect on fish’s growth and reproduction. Salty water,
sodium chloride in the water, works as a treatment from the actual toxicity
of nitrate. Fish gills take up chloride ions, which protect fish against the
nitrate poisoning (http://www.fishdoc.co.uk/water/nitrite.htm) .
Ammonia cause damage in the fish at level over 0.1mg/L. In the
Duwamish river the average level of nitrate in winter is 0.03mg/L and
0.031mg/L in summer. In June 22,1994 the level of ammonia nitrogen was
above the acceptance level (0.152mg/L). All other times ammonia nitrogen
was below the standard level.
63
Chapter VI
CONCLUSSIONS AND RECOMMENDATIONS
Water sampling in Washington rivers are done once a month during
the water sampling year. When the sample showed 1000 FC bacteria in
the Nisqually river in 12/20/1989 no new samples were taken in the same
month. Washington State should sample water more than once in the
month on exceptional occasions, if water does not meet water quality
standards and exceeding level is much higher than water quality criteria.
The urbanized area of the Duwamish watershed increases risk of river
pollution. Developing watershed runoff water quantity and quality models
will minimize flow of FC bacteria, nitrogen and metals into the river. This
by itself will reduce ecological and environmental risk to aquatic life and
people (recreational activities). Developing regional stakeholders’ and
public’s awareness programs will increase protection of watershed by
minimizing pollution level through human activities.
During the water sampling high level of FC bacteria and ammonia
nitrogen were observed in the Duwamish river. In order to minimize
pollution in the Duwamish river, stormwater runoff should be monitored
and managed. High level of infiltration systems in urbanized areas in the
Duwamish watershed should be installed. Dumping oil and grease from
64
the industrial sector should be eliminated. More clean up projects should
be implemented for the Duwamish river basin.
Concentration of metals and nitrogen in the Duwamish river should
be monitored and reduced. Increased level of nitrogen has negative effect
on DO level in water (cause oxygen depletion in rivers).
In 1996 the Nisqually river was listed in 303(d) list6 (do not meet
water quality standards for Fecal Coliform bacteria), Total Maximum Daily
Loads (TMDL)7 study conducted from March 2002 to September 2003 for
the Nisqually river showed improved trends and met FC bacteria water
quality standards (Ecology, 2007). Repairing on-site sewage systems and
managing loads of FC bacteria from the animal farms in the Nisqually river
are the main approaches to reduce flow of FC bacteria into the river. The
Pierce County Department of Community Services Housing Programs,
Nisqually Tribe, Thurston Conservation District , Tacoma-Pierce County
Health Department and Washington State Department of Transportation
are working together to reduce risk of river pollution from the FC bacteria.
The Tacoma-Pierce County Health Department is developing onsite sewage system management plan to identify type of on-site sewage
systems in Pierce County, enforce maintenance of these systems, and
reduce and eliminate potential health risks from these sewage systems in
the Nisqually water basin. Evidence of pet feces occurred during the
TMDL study. The Washington State Department of Transportation started
6
List for water bodies, which do not meet water quality standards
TMDL identifies how much pollution needs to be reduced to achieve clean water. (Ecology,
2007)
7
65
managing pet waste for the Nisqually basin area. The Nisqually Tribe is
planning to manage the removal of animal farms (located very close to
watershed) from the Nisqually watershed area.
Landowners’ awareness programs are planned by the Thurston
Conservation District to develop conservation and restoration plans, and
implement best management practices (C. James, 2007).
Managing stormwater runoff is one of the main tasks for reducing
pollution of the Nisqually river basin. Creating storwater infiltration systems
and bioretention cells (rain gardens) to treat stormwater (agricultural)
runoff will reduce pollution flow into the river. Infiltration systems and bioretention cells filtrate storwater from pesticides, nutrients, nitrogen, oil and
grease. Filtrated water will have less negative effect on water quality
parameters and therefore on fish.
66
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http://dnr.metrokc.gov/wlr/waterres/hydrology/DataReport.aspx , access
April 2007
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http://www.ecy.wa.gov/apps/watersheds/riv/station.asp?theyear=&tab=fina
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68
