RMP Coring Study Wrapup RMP CFWG Meeting June

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RMP Coring Study Wrapup RMP CFWG Meeting June 2010

RMP Coring Study Wrapup RMP CFWG Meeting June 2010

Core- What Is It Good For? • Bay pollutant inventory – erosional time bombs?

Core- What Is It Good For? • Bay pollutant inventory – erosional time bombs? • Model validation – Conceptual &/or mechanistic • Model development – Empirical, mechanistic, hybrid – Can recalibrate, but better up front

RMP/CEP Sites (Bay) • Representative – inventory, sedimentation • 3 sites Central Bay, 2

RMP/CEP Sites (Bay) • Representative – inventory, sedimentation • 3 sites Central Bay, 2 sites each other segments • Preference to RMP repeat stations

Distribution of Sites (Wetland) • Loading history – Depositional zones • 1 site each

Distribution of Sites (Wetland) • Loading history – Depositional zones • 1 site each segment – – – Pt Edith Martinez Wildcat Richmond Damon Sl. Oakland Greco Island Coyote Creek • +1 watershed site – Alviso Marina

Bay Hg Results < 1960 < 1960

Bay Hg Results < 1960 < 1960

Conceptual Model Fits in Bay • Radiodating fits bathymetric history – North Bay erosive

Conceptual Model Fits in Bay • Radiodating fits bathymetric history – North Bay erosive (137 Cs near surface) – Central, South Bay ~neutral, or erosive – Lower South Bay depositional • Contamination fits sediment history – Top core sections ~ RMP surface sediments – Lower contamination in deepest sections • pre industrial background – Contaminants elevated in industrial period • Metals ~uniform downcore, PCBs higher nearer surface

Wetland Hg Results < 1960 < 1960

Wetland Hg Results < 1960 < 1960

Wetland Results • Radiodating fits sea level rise – All areas net depositional (2

Wetland Results • Radiodating fits sea level rise – All areas net depositional (2 -3 mm/year) – Lower South Bay subsided, higher deposition • Contamination fits sediment history – Top core sections ~ RMP surface sediments – Usually lower contamination in deepest sections • pre industrial background – Contaminants elevated in industrial period • Sharper/higher peaks than in Bay cores • Watershed (Alviso) site ambiguous – Rapid deposition, but where is Hg peak?

Core- What Was It Good For? • Bay pollutant inventory – Few time bombs

Core- What Was It Good For? • Bay pollutant inventory – Few time bombs other than LSB, wetlands • Model validation – Results fit conceptual model of • mostly terrestrial/watershed sources • In-Bay dispersion, dilution • Model development – Some data for next generation of models

Immediate Next Steps • Close of review comment period • Revisions, final report July

Immediate Next Steps • Close of review comment period • Revisions, final report July 5 Near-term additions • Dioxins in Bay cores (4 -5 sections x 11 cores) for exposure risk $57 k – Need wetlands if info on loading history needed • Any need for more PBDEs? – Only 3 wetlands. Remaining wetlands (+Bay) would provide contrast to older legacy – Lab currently has samples, will discard

Longer Term Next Steps? • Better than before, but enough? – N = 11

Longer Term Next Steps? • Better than before, but enough? – N = 11 from RMP/CEP + 2 -5 from USGS • N depends on which analytes – OK for Baywide scale but few for segment specific modeling (N=2) – Nothing in shallow waters (<2 m) • Time frame needed – Before new models need data • Resolution needed – What scale are we actually planning to act on?

Logistical Lessons 1. Waiting for preliminary radiodating slowed study 2. Created backlog at RMP

Logistical Lessons 1. Waiting for preliminary radiodating slowed study 2. Created backlog at RMP laboratories (3+ years equivalent of S&T samples) 17 cores x 10 sections/core = 170 samples 3. Total cost $300 k+, hard to reduce, especially analytical costs (1 site = 10 samples x X analytes)

Incremental Efforts 1. 2 Bay sites (optionally +1 wetland? ) in one Bay segment

Incremental Efforts 1. 2 Bay sites (optionally +1 wetland? ) in one Bay segment per year 2. Gravity/hammer core in Bay, Livingstone (piston) core in wetland 3. Analyze up to 10 sections at ~10 cm (skipping) intervals Cost ~$50 k for Bay cores, ~$75 w/ wetland (PCBs, Hg, metals, TOC, grainsize)

+/- Incremental Approach • Few sites, more often (e. g. 2 per segment, different

+/- Incremental Approach • Few sites, more often (e. g. 2 per segment, different ones yearly) + Better workload for labs (20+ vs 100+ samples at once) + Costs better spread for RMP + Can get info on segments w/ greatest data needs first - Long time to get full Baywide set • Other details decided depending on program needs

Back to Basic Questions • Do we need more cores? – Probably, especially if

Back to Basic Questions • Do we need more cores? – Probably, especially if we plan sub-segment scale models • All at once, or a few at a time? – A few at a time is easier for many logistical and budget reasons • When, where, how many? – Best early/before models finished, random/ representative of areas modeled, # samples depending on model questions, scale