Toxic 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 (Poster session 10D)

– 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)

Goals

• Provide concentration data for toxic chemicals entering Puget Sound– To reduce uncertainty of outputs from Puget

Sound Toxics Box Model →

• Provide concentration data for toxic chemicals in Puget Sound– To calibrate the Box Model

Objectives• Measure concentrations of toxics in:

– Surface and deep waters of Puget Sound basins and ocean boundary waters

– Five largest tributaries to Puget Sound– Suspended particulate matter (SPM) at the

same marine and freshwater sites• Evaluate spatial and temporal variability in

concentrations• Calculate loads

Sampling Design: Marine Waters• 7 stations representing

Box Model cells andmain ocean boundary

• 2 depths per station• 3 seasons: summer,

fall, and winter

• 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

Results: Marine Water Column

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: 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

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

• Most parameters exported• Cadmium and lead imported

Results: Ocean Exchange

Parameter Estimated Net Exchange (mT/yr)

Direction of Net Transport (based on current study)

TSS +160-330 x103 Export TOC +240-400 x103

Total Arsenic +24-28 Total Cadmium -3.2 to -3.9 Import Total Copper +30-110 Export Total Lead -18 to -20 Import Total Zinc 0-150 Export Total PAHs -6 to +9 Uncertain – based on ND Total PCBs -0.001 to +0.001 Uncertain – insufficient data Total PBDEs -3.8 to +0.2 Uncertain – data too variable

Sampling Design: Marine SPM

Sediment traps• Five sites and 1-2 depths• Represented Box Model

boundaries / cells• From Nov ‘09 – Jan ‘10

Results: Marine SPM • Only recovered deep Hood Canal traps !

• Analyzed SPM from ‘08 South Sound traps

• Gross sedimentation < urban embayments

• Chemical fluxes in Hood Canal < in South

Sound (except copper)

• Rates can be compared to Box Model-

predicted sedimentation losses

Conclusions: Marine Waters

• Detected parameters found in low concentrations• Organic carbon, metals, and PCB concentrations

similar to other studies• Semivolatile organics, PAHs, and chlorinated

pesticides seldom detected• PCBs greater in Puget Sound and at depth• PBDE concentrations relatively high and variable• Most parameters likely exported out of Puget

Sound (cadmium imported)• Sedimentary flux of toxics associated with SPM in

Hood Canal less than in more developed basins

Sampling Design – 5 Rivers• Depth-integrated

samples at 3 quarter points in channel

• Surface grabs for petroleum-related compounds

Conclusions - Rivers

• Concentrations of most detectable parameters low and similar to other studies

• Petroleum-related compounds, BNAs and chlorinated pesticides seldom detected

• Organics detected more often in SPM• Some spatial and temporal differences• Most measured daily loads within ranges

estimated from monitoring studies

Summary• Low detection frequency for many organic

compounds in marine and river water• When detected, concentrations of toxics in marine

and river water generally low• Concentrations in Puget Sound often greater than

in ocean boundary waters• Concentrations in deep layers often greater than

in surface layers• Net export of toxic chemicals out of Puget Sound,

except cadmium and lead

• Sedimentation and flux of toxic chemicals greater

in basins with more developed watersheds

• Concentrations of conventionals, nutrients, and

metals in river water similar to other studies

• Marine and river water results improve choice of

input values for the Puget Sound Box Model and

ability to calibrate it

• Organic chemicals more likely to be detected in

SPM than in water samples

Summary (continued)

Recommendations• To improve estimates of external loading:

– Sample more intensively near model boundaries and measure concentrations of most variable toxics (PBDEs)

– Sample more frequently (especially during storm-related flows) and analyze fewer chemicals

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

• Skim through report: http://www.ecy.wa.gov/biblio/1103008.html

Recommendations

Acknowledgments

Ecology 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