Toxic Chemicals in Puget Sound and Major Tributaries Tom Gries and David Osterberg Washington 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 and main 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
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 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 and 25 th -75 th percentile concentrations … Most parameters exported Cadmium and lead imported Results: Ocean Exchange
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
Depth-integrated samples at 3 quarter points in channel Surface grabs for petroleum-related compounds
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: 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 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 SPM from 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 µg/Kg TPAH (mean = 120 µg/Kg) Mean PCBs = 410 ng/Kg Mean PBDEs = 1700 ng/Kg