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RMP Coring Plans 2010 and Onward RMP CFWG Meeting June 2009.

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Presentation on theme: "RMP Coring Plans 2010 and Onward RMP CFWG Meeting June 2009."— Presentation transcript:

1 RMP Coring Plans 2010 and Onward RMP CFWG Meeting June 2009

2 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

3 Approach RMP/CEP Select RMP S&T (random) and continuous (undiked) wetland sites 2.Vibracore in Bay, Livingstone (piston) core in wetlands/watershed 3.Freeze long core sections in field 4.Saw core into 2.5cm sections 5.Analyze sections at ~15 year intervals Using prelim. radiodating, literature estimates

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

5 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

6 Lessons RMP/CEP Waiting for preliminary radiodating slowed study 2.17 cores x 10 sections/core = 170 samples 3.Created backlog at RMP laboratories (3+ years equivalent of S&T samples) 4.Total cost $300k+, hard to reduce, especially analytical costs (1 site = 10 samples x X analytes)

7 Conceptual Model Sedimentation (from isotopes, bathymetric history) –Similar in segment (shared water, sediment) –But mesoscale differences (trib/shore proximity, etc) Pollutant distribution function of –Sedimentation history –Local land use/ loading

8 Bay Hg Results < 1960

9 Conceptual Model Fits Radiodating fits bathymetric history –North Bay erosive ( 137 Cs, 210 Pb 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

10 Wetland Hg Results < 1960

11 Wetland Results Radiodating fits sea level rise –All areas net depositional (2-3mm/year) –Lower South Bay subsiding, 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?

12 Need Cores? Better than before, but enough? –N = 11 from RMP/CEP from USGS N depends on which analytes –Maybe OK for Baywide scale but not enough for segment specific modeling (N=2) Time frame needed –Before models need new data Resolution needed

13 Option 1: Repeat 2006 Effort RMP S&T (random) sites, 5 wetland, all Bay segments 2.Gravity/hammer core in Bay, Livingstone (piston) core in wetland 3.Freeze/saw subsampling 2.5cm sections 4.Analyze up to 10 sections at ~10cm (skipping) intervals ( samples) PCBs, PBDEs, metals, TOC, grainsize 5.Total cost $350k+ ($300k in 2006)

14 Option 2: Incremental Efforts 1.2 RMP S&T (random) sites (optionally +1 wetland?) in one Bay segment per year 2.Gravity/hammer core in Bay, Livingstone (piston) core in wetland 3.Freeze/saw subsampling into 2.5cm sections 4.Analyze up to 10 sections at ~10cm (skipping) intervals PCBs, PBDEs, metals, TOC, grainsize 5.Cost ~$50k for Bay cores, ~$75 w/ wetland

15 Budget 2010, Two Bay Cores Sample Collection & Processing$5,500 Laboratory Analysis$34,250 Radiodating 6600 PCBs, PBDEs Metals, Hg 6400 TOC, grainsize 2500 Proj Mgmnt, QC & Reporting$8,000 Total$47,750

16 +/- Incremental Approach Few sites, more often (e.g. 2 per segment, 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 can be decided depending on program needs

17 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 Qs

18 Nitty Gritty Details Example design to follow if desired

19 Siting Approach Use new random RMP S&T sites + Continue to build larger scale spatial data ± May get stations w/ similar characteristics - Low odds for special sites of interest (hot spots, watershed deltas, dep/erosional

20 Sampling Approach Unpowered (push/gravity/hammer) cores + Low equipment needs/cost -Cores >1m deep may be difficult

21 Sectioning Approach Field freezing, saw sectioning + Easy sectioning post sampling (solid core) + No hold time issues (within ~1 year) -Freezing causes core distortion -Clean (e.g. Teflon) saw difficult/impossible, but the devil we know (Alternatively) Field or lab extrusion + No freezing needed (~ambient or cooler chilling) ± Cleanliness unknown, depends on execution (staff, location, equipment) -Need extruding equipment/attachments

22 Analysis Approach Select set interval subsamples + Know which sections to send to labs a priori + Results from radiodating/chem labs sooner -Less flexibility on section spacing (longer or shorter cores, fast/slow deposition areas) ± (alternatively wait for radiodating, irregular spacing) Skip sections + No need to composite 1 sample = 1 section, -May miss narrow peaks (how likely?) ± (alternatively composite sections)

23 Analysis Approach Analyte selection- highest needs for particle associated persistent pollutants of concern –PCBs –Hg –PBDEs (top 5 sections each core) –??? Add geologic /anthropogenic factors –ICP-MS trace elements –TOC, grainsize

24 Approach Summary 1.2 RMP S&T (random) sites (optionally +1 wetland?) in one Bay segment per year 2.Gravity/hammer core in Bay, Livingstone (piston) core in wetland 3.Freeze/saw subsampling into 2.5cm sections 4.Analyze up to 10 sections at ~10cm (skipping) intervals PCBs, PBDEs, metals, TOC, grainsize 5.Cost ~$50k for Bay cores, ~$75 w/ wetland

25

26 Dating: Bathymetric History (USGS Bruce Jaffe) Sum bathymetric changes between surveys + deposition – erosion Some sites depositional & erosional different periods

27 Dating: Isotopes (USC Hammond) Cs in A-bomb –max ~1960 Pb decay –half life 22 yrs –Decay/ mixing dilution can look similar If Cs & Pb similar –likely mixing dilution

28 LSB001: Fast accumulation ~150cm to 1960~60cm to 1960

29 LSB002: Fast accumulation ~130cm to 1960~30cm to 1960

30 LSB Wetland Deposition ~80cm to 1960

31 Hg Analyses ICP-MS HF extract (CCSF) vs CVAFS aqua regia (MLML)

32 Lower South Bay 1960 = 30-60cm bay, 80cm C.Creek

33 LSB Metals Downcore concentrations noisy –Coyote Creek Hg max > Alviso! –Coyote Hg 1960s depth (80cm) –Coyote Cu 40cm = 1980s? ~max Cu discharge late 1970s (Palo Alto) ~surface sediment Cu USGS long term data

34 Conaway 2004 vs Current 5nmol/g ~ 1mg/kg

35 Lower South Bay PCBs PCB in bay cores max subsurface –LSB001 (60cm =1960) –LSB002 (30cm = 1960)

36 SB001: Continuous Erosion? ~0cm to 1960~15cm to 1960 Core ID: SB001, X: , Y: depth: depth: depth: depth: depth: depth: depth: -161 Reconstructed horizons: 0

37 SB002: No Change ~1950s ~0cm to 1960~12cm to 1960

38 SB Wetland Deposition ~30cm to 1960

39 South Bay Metals Downcore concentrations noisy –Cu Greco Island similar to Coyote, but into 1960s zone. –Greco Hg max ~uniform in wetland to 55cm = 1930s? (1960s Cs penetration to 30cm)

40 South Bay 1960 = 12-15cm bay, 30cm wetland

41 PCB in bay max near surface –SB001 (continuous erosion) at top ~5cm –SB002 (no change since 1950s) ~10cm South Bay 1960 = 12-15cm bay, 30cm wetland

42 CB001: No Change ~1940s ~0cm to 1960~5cm to 1960

43 CB002: Erosion to ~1920s ~0cm to 1960~20cm to 1960

44 CB006: Continuous Erosion ~0cm to 1960~12cm to 1960 Core ID: CB006A, X: , Y: depth: depth: depth: depth: depth: -220 Reconstructed horizons: 0

45 Central Bay Metals Bay downcore concentrations smaller range than in SB/LSB No dating for wetland cores yet –~20cm subsurface max for Hg, Se, Cu in wetland, –Similarly high conc for Se, surface, 60cm

46 Central Bay 1960 = 5-20cm bay, ?? wetland

47 PCB in bay max near surface –CB sites no change or eroding Central Bay PCBs 1960 = 5-20cm bay, ?? wetland

48 SPB001: Erosion to ~1920s ~0cm to 1960~5cm to 1960

49 SPB002: Erosion to ~1880s ~0cm to 1960~2cm to 1960

50 San Pablo Metals ~20cm surbsurface max for Hg, Se, Cu in wetland –No dating for wetland cores yet –No secondary metal peaks –Deeper concentrations fairly constant

51 San Pablo Bay 1960= 2-5cm bay, ?? wetland

52 PCB in bay max near surface –SPB sites eroding, no reservoir San Pablo Bay PCBs 1960= 2-5cm bay, ?? wetland

53 SU001: Erosion to ~1910s ~0cm to 1960~2cm to 1960

54 SU002: Erosion to ~1890s ~0cm to 1960~80cm to 1960?!!

55 Suisun Metals Hg highly Pt Edith and SU002 –No dating for wetland cores yet SU002 max concentrations in top section –Hg, Se, Cu, subsurface spikes as well

56 Suisun Bay 1960 = 2-80cm?! bay, ?? wetland

57 PCB signal mixed –Bay sites erosional according to bathymetry –SU002 mixed history (PCBs > RMP surface seds at 100cm) Suisun Bay PCBs 1960 = 2-80cm?! bay, ?? wetland

58 Results Sedimentation in segment ~similar (bathymetry, isotopes) –Suisun, San Pablo eroding –Central, South neutral/eroding –Lower South accreting Erosional areas Cs penetration = mixing? –Pollutant penetration by same mechanism

59 Results Sites within segments similar (from bathymetry and radiodates) –Suisun, San Pablo eroding –Central, South neutral/eroding –Lower South accreting Wetland cores indicate loading history –Subsurface max in wetlands everywhere –Layer often near surface (1950s?)

60 Summary Wetland pollutants track loading history –Metals match SB loading history –PCBs max ~1970s Bay pollutants more complex –Some sites well mixed, or eroded –Some sites not well predicted (esp SU002) Bathymetry, Cs, Hg mismatch Multiple deposition & erosion w/ seds from different watersheds

61 Implications? Few ticking time bombs in Bay –So far, so good (2 of [ ]) –Largely WYSIWYG Surface ~ deeper for metals Surface >~ deeper for PCBs Wetland cores capture historical pulses Historical loads mostly eroded, or already dispersed in Bay

62 Next Steps Get rest of data (radiodating, organics) More analytes (dioxins?) More normalization? (TOC in wetlands) Modeling accretion vs mixing for radioisotopes (USC) Understand discrepancies among data –Complex histories Develop strategy for future coring Partial reporting (Bay core metals) for Pulse –Full reporting 2009 Q3?


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