is stormwater harming our streams?
TRANSCRIPT
STREAMS?harming our
STORMWATERIs
urbanizedwatersheds
stormwater
METALS
Long-term stream monitoring
King County, WA
Toxicity
ToxicityBaseflow comparison
ToxicityBaseflow comparisonTrends over time
ToxicityBaseflow comparisonTrends over timePollutant sources
33 sites
Seattle
Tacoma
1993-2010
grabsamples
2-6x/yr
after 24h dry & ¼” rain
ICP-MS
24 metalstotal & dissolved
Toxicity
Human health (WA Water Quality Stds)
rare:
Nickel Thallium
widespread:
Arsenic
Human health (WA Water Quality Stds)
Aquatic life (WA Water Quality Stds)
rare:
Copper Lead
common:
Mercury
Aquatic life (WA Water Quality Stds)
Salmonids (draft screening values)
Copper Lead
Salmonids (draft screening values)
Cadmium
Zinc
common towidespread:
Silver
???:
Baseflowcomparison
Baseflowcomparison2001-2003
Total concentrationshigher in stormflow:
As Cd Cr Cu Ni Pb Sb V Zn
Toxics:
Others:
Ba Be Co Fe
Total concentrations and dissolvedhigher in stormflow:
As Cd Cr CuNi Pb Sb V Zn
Ba Be Co Fe
Toxics:
Others:
Trends
Cr Cu Ni Pb Zn
Some toxics decreased
Cr Cu Ni Pb Zn
Some toxics decreased
Hardness increased
protectiveCa Mg
Sources
weathering
Iron as tracer
weathering
most metals
most streams
weathering
total
dissolved
Iron correlations
tota
l copper
(µg/L
)
total iron (µg/L)
Iron correlations
tota
l copper
(µg/L
)
total iron (µg/L)
tota
l copper
(µg/L
)
total iron (µg/L)
Iron correlations
Mill Creek:to
tal m
eta
l (µ
g/L
)
total iron (µg/L)
Mill Creek: Old industrial dumpto
tal m
eta
l (µ
g/L
)
total iron (µg/L)
Toxicity concerns:mercurycopper, lead, zinc
Trends were improving.
Weathering was amajor source.
Photo credits:• Stream sampling: King County DNRP• Lake Union aerial: Jelson25 (Wikipedia)• Stormwater outfall: Blake Feist (NOAA Fisheries)• Blacksmith: NBC News• Rain: Tuncay (Flickr)• ICP: Wblanchard (Wikipedia)• Toddler in lake: King County DNRP• Nickel: US Mint• Thallium: Rob Lavinsky irocks.com (Flickr)• Arsenic: Tomihahndorf (Wikipedia)• Aquarium: Angelo Juan Ramos (Flickr)• Copper: Jonathan Zander (Wikipedia)• Lead: KBD Photography (Flickr)• Mercury: Dedvedev (Wikipedia)• Salmon migrating: J Armstrong (UW)• Zinc: Raysonho (Wikipedia)• Cadmium: W Oelen (Wikipedia)• Silver: Elekes Andor (Wikipedia)• Seattle waterfront: Seattle DOT• Seattle historic Third Ave. construction: Seattle Municipal Archives