6. Pier 59 – The Seattle Aquarium
Elliot Bay
Duwamish River
Image from Google Earth
7. 15 Minute Data from Seattle Aquarium Station
(1/2008-present)
TopTurbidity
(1m)
Bottom
Turbidity (10m)
Rainfall
(Mithun, Inc., 2014)
(King County, 2014)
Methods
8. Data Processing
• Remove values
>500, <0 NTU
• Daily average top
& bottom
turbidity
• Daily total rainfall
• Remove 1st
portion of
dataset
• Cross-covariance
analysis
9. Cross-Covariance: Rainfall &TopTurbidity
• 4 significant time lags, -1 year, 3 days,~25 days, ~40 days
• Positive cross-covariance
• Scatter
Cross-covariance between rainfall and top turbidity from 8/2010 to 11/2014. Red line indicates significant correlation with 99% CI.
10. Cross-covariance between rainfall and bottom turbidity, 8/2010 to 11/2014. Red line indicates significant correlation with 99% CI.
• No significant cross-covariation at any time lag
Cross-Covariance: Rainfall & Bot.Turbidity
11. Discussion
• BottomTurbidity
• No cross-covariance at any time lag
• Other physical drivers?
• Tides, currents, waves
• TopTurbidity
• 3 day lag as hypothesized – urban runoff?
• -1 year likely due to seasonality
• ~25 and ~40 day lags?
12. Where is the Runoff Originating?
• Urban runoff contributes different sediment
concentrations and contaminant types than runoff
from undeveloped land
• Sampling station influenced by Duwamish River
13. Pier 59 – The Seattle Aquarium
Duwamish River
2 km
Elliot Bay
Image from Google Earth
14. • Hydraulic responses
different time lags
• 3 days – urban overland
• ~25 days, ~40 days –
Duwamish River
catchment
• Source tracking of
suspending sediment?
• Topic for future research
(Mabel, 2007)
(Brown, 2010)
15. Rainfall Patterns
• Rainfall events span multiple days
• Covariance for individual daily total rainfall
• Not representative of physical processes
• Future research
18
16
17
14
10
9
5
6
9
13
18
19
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
DaysofRainfallperMonth
Days of Rainfall per Month - Seattle, WA
(City of Seattle, 2014)
16. Stormwater Management
• Combined Sewer
Overflows
• Dry weather may reduce
sediment loading
• Wet weather may
drastically increase
loading
• Future research
(King County, 2014)
17. Calibration?
• Turbidimeters can have
calibration/performance issues
• Drift
• Negative values
• Sensor blockages spikes
• In-situ instruments difficult to
maintain
• Potential impact on results
(King County, 2014)
19. Uncertainty in Analysis
Calibration Issues
Not Capturing
Physical Processes
(Rainfall Patterns,
etc.)
Missing Data
Conclusion
• Hypothesis?
• Not proven or rejected
• Modifications to analysis
20. Top
Turbidity
in Elliot
Bay
Overland
Urban Runoff
River Flows
Stormwater
Discharge &
CSO
Other
Contributors
toTurbidity
(algae, etc.)
Conclusion
• Complex
relationship with
inputs
• More research
needed
• Turbidity
generation location
• Bottom turbidity
mechanisms
• Impact of CSO
Bottom
Turbidity
in Elliot
Bay?
22. References
• Benbennick, D. An Outline Map of Washington with County Boundaries. Wikimedia Commons. 2006.
http://commons.wikimedia.org/wiki/File:Map_of_Washington_counties,_blank.svg
• Brown, P. Image of the Duwamish River. IvestigateWest. 2010. <http://crosscut.com/2010/12/07/environment/20426/Duwamish-River-Should-cleanup-make-
fish-safe-eat-r/ >
• Chelton, D. Commentary: Short-term Climatic Variability in the Northeast Pacific Ocean. Oregon State University Press: Corvalis, OR, 1984, 87-99.
• Czuba, J., Magirl, C., Czuba, C., Grossman, E., Curran, C., Gendaszek, A., Dinicola, R. Sediment Load from Major Rivers into Puget Sound and its Adjacent
Waters. United States Geological Survey, 2011, Fact Sheet 2011-3083.
• Davis, A., Mohammad, S., Ni, S. Loading Estimates of Lead, Copper, Cadmium, and Zinc in Urban Runoff from Specific Sources. Chemosphere, 2001, 44, 997-
1009.
• Elliot Bay Waterfront Recontamination Study. Washington State Department of Ecology, 1995, Panel Publication 9, Ecology Publication 95-335.
• Goransson, G., Larson, M., Bendz, D. Variation in Turbidity with Precipiration and Flow in a Regulated River System – River Gota Alv, SW Sweden. Hydrology
and Earth System Science, 2013, 17, 2529-2542.
• Hoffman, E., Mills, Latimer, J., Quinn, J. Annual Input of Petroleum Hydrocarbons to the Coastal Environment via Urban Runoff. Can. J. Fish. Aquat. Sci., 1983,
4Q(Suppl. 2): 41-53.
• Image of Seattle Waterfront. 2013. <http://thesunbreak.com/wp-content/uploads/2013/04/IMGP2905.jpg >
• King County Marine Moorings. King County, WA, 2014. < https://green2.kingcounty.gov/marine-buoy/default.aspx>
• Combined Sewer Overflow Status. King County, WA, 2014.< http://www.kingcounty.gov/environment/wastewater/CSOstatus/Overview.aspx >
• Lahet, F., Stramskim D. MODIS imagery of turbid plumes in San Diego coastal waters during rainstorm events. Remote Sensing of Environment, 2010, 114, 332–
344.
• Mabel, J. The Green River at Tukwila.. Wikimedia Commons. 2007. <http://en.wikipedia.org/wiki/Duwamish_River#mediaviewer/File:Tukwila_-
_Duwamish_River_-_01.jpg >
• Seattle Aquarium. Mithun, Inc. 2014.< http://mithun.com/projects/project_detail/seattle_aquarium/ >
• Urban Waters Initiative, 2007, Sediment Quality in Elliot Bay. Washington State Department of Ecology, 2009, Publication 09-03-014.
• Seattle Monthly Averages and Records. The City of Seattle, 2014. < http://www.seattle.gov/living-in-seattle/environment/weather/averages-and-records>
• Schiff, K., Bay, S. Impacts of Stormwater Discharges on the Nearshore Benthic Environment of Santa Monica Bay. Marine Environmental Research, 2003, 56,
225-243.
• Ringman, S. Runoff turns Elliot Bay into murky stew. The Seattle Times. 2011. <http://seattletimes.com/html/localnews/2013981790_elliottbay20m.html >
