source tracing – lower duwamish waterway
TRANSCRIPT
Source Tracing
Lower Duwamish Waterway
Seattle Public UtilitiesOctober 24, 2013
SPU source control website:
http://www.seattle.gov/util/Services/Drainage_&_Sewer/PollutionControl/index.htm
Lower Duwamish Waterway
215 outfalls
– 151 storm drains
– 8 CSOs
� 5 mile reach
� Tidally influenced
2
– 8 CSOs
– 4 emergency overflows
– 5 ditches/swales
– 7 major seeps
– 40 unknown outfalls
Lower Duwamish Waterway
� Contaminants of concern in sediment:
– PCBs
– Arsenic
– Dioxins/furans
– Phthalates
3
– Phthalates
– PAHs
– Other metals
� ~450 sq mile upper basin
� Study area:
� 8,400 acre separated storm drain
� 20,000 acre combined sewer system
Source Samples� Inline traps
� Inline grabs
� Onsite catch basins
� Right-of-way catch basins
� Street dirt and soil
4
Source Tracing: PCBs
Hotspots
� T117
� GTSP/NBF
Samples through Dec 2012
� GTSP/NBF
� KC-Jorgensen SD
� Rainier Commons
� Others
5
Metal Shredding Facility
� Elevated PCBs, Hg found:
– Right-of-way and onsite catch basins
PCBs = 18.3 mg/kg
Hg = 2.72 mg/kg
– Inline grabs
6
– Inline grabs
PCBs = 1.6 mg/kg
Hg = 1.88 mg/kg
– Roof drains/gutters
PCBs = 4.6 mg/kg
Hg = 2.56 mg/kg
� Transport pathways:
– Fugitive dust
– Track out
– Stormwater runoff
Shredder
Storage yard
Metal Shredding Facility
� SPU cleans storm drains
in 2009-2010
� PCBs and Hg elevated in
CB adjacent to driveway
entrance within 6 months
� CB cleaned several times,
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Shredder
Storage yardStorage yard
Shredder
Shredder
Storage yard� CB cleaned several times,
but PCBs, Hg remain
elevated
Metal Shredding Facility
� SPU issued NOV (2009), negotiated voluntary compliance agreement (2010-2011)
– Route roof runoff through onsite treatment system
– Sweep streets
Shredder
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– Sweep streets
– Install Filterra™ unit in problem catch basin
� State revising NPDES permit
Storage yard
ASR-”fluff” pile
Material stockpile
Old BreweryPCBs in building paint
� 2004: Found 10 mg/kg PCBs
in ROW catch basin
� Up to 321,000 mg/kg in
exterior building paint
� EPA TSCA site
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� EPA TSCA site
� 2013: EPA reviewing Work
Plan for cleanup
Old BreweryPCBs in building paint
� 2004: Found 10 mg/kg PCBs in
ROW catch basin
� 2008: SPU jets and cleans lines
� Owner installed filter fabric in
CBs
� 2012: SPU re-samples lines
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� 2012: SPU re-samples lines
PCBs elevated (7.3 – 12.4
mg/kg)
� 2013: Rainier Commons jets
and cleans lines again.
Ecology Building Survey
1,000
Min
� Composite samples from buildings constructed 1950-1977
� 2 or more buildings per composite
� 38 Paint and 17 caulk samples
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0.88
3
0
1
10
100
Paint
PC
Bs (
mg
/kg
)
Min
Max
Median
Average
Caulk
39% detect 47% detect
PCBs: Land Use
92%
47%
40%
50%
60%
70%
80%
90%
100%
Perc
en
t d
istr
ibu
tio
n
PCBs in SPU source samples
Residential (n = 84)
Industrial (n = 631)
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2% 2% 1% 1% 1%
10%15%
7%3% 2% 5% 2% 2% 3% 2% 2%
0%
10%
20%
30%
<130
130 -
200
200 -
400
400 -
600
600 -
800
800 -
1,0
00
1,0
00 -
2,0
00
2,0
00 -
3,0
00
3,0
00 -
5,0
00
5,0
00 -
10,0
00
10,0
00 -
50,0
00
>50,0
00
Perc
en
t d
istr
ibu
tio
n
PCBs (ug/kg dw)
Arsenic
� Marine lumber storage yard
� Ammoniacal copper zinc
arsenate (ACZA)
� 710 mg/kg As in dirt in yard
� 750 mg/kg As in ditch in
street
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Arsenic
� Find 544 mg/kg As in ditch downstream of property
� Ecology order owner to cleanup
� Owner cleans up 10’ x 100’ section of ROW
� Up to 220 mg/kg As remains at edge of excavation
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