RESULTS OF TEN YEAR MONITORING PROGRAM AT PIER 53-55 SEDIMENT CAP

ALONG SEATTLE WATERFRONT

CAP 54 WHERE ARE YOU ?

HOW HAVE YOU BEEN FOR THE PAST 10 YEARS ?

ARE YOU READY FOR COMPANY ?

Metro’s Report in 1984 Showed Toxicant Problems In Elliott Bay

Metro Funding Treatment Plants Limited Funding For Cleanup

• Expensive Construction Projects– West Point plant to secondary treatment– Expansion at Renton plant – Move Renton discharge to Puget Sound

• Inexpensive Sediment Cleanup Projects– In-Place Sediment Cap at Denny Way CSO

using clean sand US Army CORP dredged.

Elliott Bay/Duwamish Restoration Program (EB/DRP)

• 1990 Lawsuit by NOAA against Metro and City of Seattle

• Announced same day Metro started in-place capping at Denny Way CSO (March 1990)

• 1991 Settlement by Metro and City of Seattle for $ 24 Million

EB/DRP Provided Funds For Three Sediment Cleanup Projects

• $ 12 Million – SEDIMENT REMEDIATION – 3 Projects

• $ 2 Million – ADDED SOURCE CONTROL – 2 Basins

• $ 10 Million - HABATAT ENHANCEMENT – 6 Projects

EB/DRP Projects Show In-place Capping Costs Less

• 1992 - Pier 53-55 In-Place Sediment Cap-- 4.5 Acres cost -- $ 300 Thousand

• 1999 - Norfolk CSO - Dredge and Cap-- 1 Acre cost -- $ 2 Million

• 2004 - Duwamish/Diagonal Dredge & Cap-- 7 Acres cost -- $ 10 Million

Location of Pier 53-55 cap

Cap Covers Area Off Pier 53 - 55

Pier 54 Where Are You ?In The Middle At Iver’s !

Man Admires Seattle Views

Man Looks For Pier 53-55 Cap

Six Monitoring Tasks Required

• 13 -- bottom stakes to show cap thickness • 7 -- stations show surface chemistry change• 4 --stations show benthic recolinization• 5 --coring stations show chemical isolation• 3 -- diver video transects show cap surface• 4 -- monitoring reports

Expanded Sampling Frequency

• DENNY WAY CAP• 1990 - Baseline• 1991 - 1-yr postcap• 1992 - 2-yrs postcap• 1994 - 4-yrs postcap

• 1996 - 6-yrs postcap

• 2000 - 10-yrs postcap

• PIER 53-55 CAP• 1992 - Baseline• 1993 - 1-yrs postcap

• 1996 - 4-ys postcap

• 2002 - 10-yrs postcap

Importance Of Cap Monitoring

• Supported decision to cap large area of Eagle Harbor to isolate high PAH’s.

• Supported decision to cap where Bell Street Marina is located along Seattle waterfront.

• Provides support to using capping as method for cleaning up Seattle waterfront.

Thanks For Good Monitoring

• Field sampling -- KC field crew• Sample preparation and analysis -- KC labs

– (conventionals lab, metals lab, organics lab, aquatox lab)

• Monitoring reports-- KC marine monitoring

• Diver work -- Outside contract• Bentic taxonomy -- Outside contract

Liberty RV and Diver Boat

Buoys mark stations

Diver measures stakes on bottom

Bottom stake

and

measuring rod

Surface grab sampler

Coring equipment and diver

Core samples through cap

Removing Old Wing Wall Greatly Impacted Cap Surface

13 Measuring Stake Locations

4 Benthic Taxonomy Stations

5 Coring Station Locations

7 Surface Chemistry Stations

LPAH Source Spreads To Cap

HPAH Source Spreads To Cap

Lead Source Spreads To Cap

LPAH Distribution Gradient

Total LPAH

0100020003000400050006000700080009000

10000

VG5 VG6 VG2 VG1 VG3 VG4 VG7

Con

cent

ratio

n in

ppb

, Dry

Wei

ght

May 92

May 93

Jul 94

Aug 96

Sep 02

HPAH Distribution Gradient

Total HPAH

02000400060008000

100001200014000160001800020000

VG5 VG6 VG2 VG1 VG3 VG4 VG7

Con

cent

ratio

n in

ppb

, Dry

Wei

ght

May 92

May 93

Jul 94

Aug 96

Sep 02

Copper Distribution Gradient

Copper, Total ICP

0102030405060708090

100

VG5 VG6 VG2 VG1 VG3 VG4 VG7

Con

cent

ratio

n in

ppm

, Dry

Wei

ght

May 92

May 93

Jul 94

Aug 96

Sep 02

LPAH Change With Time

Total LPAH

-5000

5000

15000

25000

35000

45000

55000

65000

75000

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in

ppb

, dry

wei

ght

VG5

VG6

VG2

VG1

VG3

VG4

VG7

Expanded LPAH Change

Total LPAH

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in

ppb

, dry

wei

ght

VG5

VG6

VG2

VG1

VG3

VG4

VG7

HPAH Change With Time

Total HPAH

0

10000

20000

30000

40000

50000

60000

70000

80000

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in p

pm, d

ry w

eigh

t

VG5

VG6

VG2

VG1

VG3

VG4

VG7

Expanded HPAH Change

Total HPAH

0

5000

10000

15000

20000

25000

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in

ppm

, dry

wei

ght

VG5

VG6

VG2

VG1

VG3

VG4

VG7

Lead Change With Time

Lead

0

20

40

60

80

100

120

140

160

180

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in m

g/kg

, dry

weigh

t

VG5

VG6

VG2

VG1

VG4

VG3

VG7

Phthalate Change With Time

Bis(2-Ethylhexyl) Phthalate

0

50

100

150

200

250

300

350

400

450

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in

ppb

, dry

wei

ght

VG5

VG6

VG2

VG1

VG3

VG4

VG7

PCB Change With Time

Total PCB

0

20

40

60

80

100

120

140

160

May 92 May 93 Aug 96 Sep 02

Con

cent

ratio

n in

ppb

, dry

wei

ght

VG5

VG6

VG2

VG1

VG3

VG4

VG7

CONCLUSIONS:• Adjacent activities can recontaminate cap.• Impact gradient with distance from source.• PAHs and metals at moderately impacted

stations drop to equilibrium in 3 years.• Takes more than 9 years at most impacted. • PAHs and metal way below standards.• PCBs and Phthalates increasing.• One phthalate exceeds standard at one site.

Why More In-Place Capping Is Appealing For Seattle Waterfront• Provides clean bottom for biota.• Less expensive than dredging and disposal.• Less dispersion of contaminate sediment.• Useful for cleaning up large area of bottom.• Can be used near existing pier structures.• Can be used under existing piers• Reduces resuspension and recontamination.