Characterization ofToxic Chemicals in Puget Sound

and Major Tributaries

Tom Gries and David OsterbergWashington State Department of Ecology

Introduction

• Puget Sound Toxics Loading Analysis– Compiled relevant information, estimated loads,

identified data gaps

– Developed box model for transport and fate of toxic

chemicals (e.g., PCBs)

– Estimated loading after land use-based water quality

monitoring in two watersheds (Wed 6A)

– Estimated loading from ocean exchange and from

monitoring near mouths of major rivers

– Synthesis (Platform session 1A)

Objectives

• Measure concentrations of toxic chemicals in and entering Puget Sound– To reduce uncertainty of

Box Model outputs →– To calibrate Box Model

• Assess spatial and temporal variability

• Estimate loads

Sampling Design: Marine WatersCollected water samples from:• 7 stations• 2 depths/station• 3 seasons

Sampling Design: Marine SPMCollected SPM in sediment traps• Moored at 5 sites• Trap array at 1-2 depths• Nov 2009 to Jan 2010

Sampling Design – Major Rivers• Collect depth-integrated

samples from 3 quarter points in each channel

• Collect surface grabsfor petroleum-related compounds

• TSS, organic carbon, and metals similar to other studies; most organics seldom detected

• POC, total zinc, and PBDEs most variable• Total PCBs < recent Canadian study• Total PBDEs often 10X Canadian study

Parameter (UOM) Det. Freq. Min. Median Mean CV Max.

TSS (mg/L) 100 0.8 1.6 1.7 0.60 6.0 DOC (mg/L) 100 0.61 0.75 0.76 0.12 0.97 POC (mg/L) 100 0.03 0.06 0.13 2.44 1.78 TOC (mg/L) 100 0.66 0.81 0.89 0.43 2.75 Total Arsenic (µg/L) 100 1.16 1.41 1.42 0.06 1.56 Total Cadmium (µg/L) 100 0.059 0.084 0.085 0.12 0.112 Total Copper (µg/L) 100 0.19 0.38 0.41 0.52 1.37 Total Lead (µg/L) 88 0.015 0.070 0.085 0.64 0.230 Total Zinc (µg/L) 100 0.41 0.69 0.86 1.23 7.44 Total PCBs (pg/L) 100 6.09 24.0 26.3 0.57 75.1 Total PBDEs (pg/L) 24 51.0 749 2,860 1.98 18,700

Results: Marine Water Column

Results: Spatial Variability• DOC, copper, lead, PCBs: PS > OB• Cadmium: ocean boundary > Puget Sound

• Deep > Surface– Arsenic, total lead– Total PCBs →

• Surface > Deep– DOC in ocean

boundary waters

Results: Spatial Variability

Results: Ocean Exchange

• Net exchange = Mass exported – Mass imported

• Mass exported = volume out x flow-weighted concentrations of surface layer at Main, Whidbey and Hood Canal basin sites

• Mass imported = volume into Puget Sound x concentrations of deep layer at Haro Strait and San Juan de Fuca sites

EBSI

CB

• Boundaries• Admiralty Inlet• Deception Pass

• 2-layer circulation• Deep water flows into

Puget Sound• Surface water flows out

of Puget Sound

Parameter Estimated Net Exchange

(mT/yr) Direction of net transport (based on current study)

TSS (mg/L) 160 - 330 (x1000) Export

TOC (mg/L) 240 - 400 (x1000) Export

Arsenic (µg/L) 24 - 28 Export

Cadmium (µg/L) -3.3 to -3.9 Import

Copper (µg/L) 30 - 105 Export

Lead (µg/L) -18 to -20 Import

Zinc (µg/L) 0 to 150 Export

Total PAHs (µg/L) -6 to +9 Unknown – based on nondetects

Total PCBs (pg/L) -0.001 to +0.002 Unknown – insufficient data

Total PBDEs (pg/L) -3.8 to +0.2 Unknown – too variable

• Based on model-predicted water fluxes and25th-75th percentile concentrations …

• Most parameters exported• Cadmium and lead imported

Results: Ocean Exchange

ConclusionsGeneral• Concentrations of toxics low in marine

waters and near mouths of rivers• Concentrations of non-halogenated

organics seldom detected in whole water• Organics detected more frequently in

samples of SPM

Marine waters• Concentrations of organic carbon, and

metals similar to other studies• Concentrations of toxics often greater in

Puget Sound and at depth (e.g., PCBs)• PBDE concentrations high and variable• Net export of most toxic chemicals out of

Puget Sound (except cadmium and lead)

Conclusions (continued)

Marine SPM• Sedimentation and flux of toxic chemicals

greater in basins with more developed

watersheds

• Chemical fluxes in Hood Canal less than in

South Puget Sound (except copper)

• Rates can be compared to Box Model-

predicted losses via sedimentation

Conclusions (continued)

River water• Concentrations of conventionals, nutrients, and

metals in rivers similar to other studies• Most measured daily loads from river mouths

within ranges estimated from

monitoring/modeling

Overall?• Results improve choice of input values for the

Puget Sound Box Model and ability to calibrate it

Conclusions (continued)

Recommendations• To further improve estimates of external

loading, sample more intensively near model boundaries and measure concentrations of most variable toxics (PBDEs)

• To improve detection frequency of non-polar organic compounds, focus future sampling on collection/analysis of SPM

• See details: http://www.ecy.wa.gov/biblio/1103008.html

AcknowledgmentsEcology staff:Bruce Barbour, Julia Bos,Randy Coots, Karin Feddersen, Mya Keyzers, Stuart Magoon, Jim Maroncelli, Dean Momohara, Dale Norton, Greg Pelletier,Brian Pickering, Mindy Roberts, Nancy Rosenbower, Dave Serdar, Janice Sloan,John Weakland, Leon Weiks,Jeff Westerlund

Reserved Slides

Parameters Measured• Metals (dissolved and total arsenic, cadmium, copper,

lead, and zinc)• Organic compounds (33 chlorinated pesticides, 55

semivolatile organics, 22 PAHs, 209 PCB congeners, 26 PBDE congeners)

• Conventional parameters (total suspended solids, dissolved and total organic carbon)

• Nutrients (nitrogen and phosphorus), hardness, and petroleum-related compounds (TPH and oil and grease) in river water only

• Total PCB Concentrations– Range 6.9-75.1 pg/L (mean = 26.3 pg/L)– Puget Sound (30.7 pg/L) > Ocean Boundary (20.4 pg/L)– Ocean boundary < Dangerfield et al, 2007 (42 pg/L)– Deep layer (32.7 pg/L) > surface layer (15.1 pg/L)

• Total PBDEs– Detection frequency <25%– Range 50-19,000 pg/L (mean = 2900 pg/L)– Measured concentrations highly variable– 6/10 detections and two highest concentrations from

ocean boundary sites– Results often 10X greater than Dangerfield et al study

Results: Marine Water Column

Sampling SPMfrom Rivers

River SPM Results

• Detection frequency 20% for petroleum-related

compounds, semivolatile organics, and chlorinated

pesticides

• 16 of 22 PAHs measured routinely detected in SPM

with 30-210 µg/Kg TPAH (mean = 120 µg/Kg)

• Mean PCBs = 410 ng/Kg

• Mean PBDEs = 1700 ng/Kg