rmp coring plans 2010 and onward rmp cfwg meeting june 2009
TRANSCRIPT
RMP Coring Plans 2010 and Onward
RMP CFWG Meeting June 2009
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
Approach RMP/CEP 2006
1. 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 intervalsUsing prelim. radiodating, literature estimates
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 segment– Pt Edith Martinez– Wildcat Richmond– Damon Sl. Oakland– Greco Island– Coyote Creek
• +1 watershed site– Alviso Marina
Lessons RMP/CEP 2006
1. 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)
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
Bay Hg Results
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
LSB001LSB002
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SB001SB002
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
CB001CB002CB006
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SPB001SPB002
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SUB001SUB002
< 1960
< 1960
< 1960< 1960 < 1960 < 1960
< 1960< 1960
Conceptual Model Fits
• Radiodating fits bathymetric history– North Bay erosive (137Cs, 210Pb 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
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
LSB AlvisoLSB Coyote
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SB Greco
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
CB Damon
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SPB Wildcat
CONC (mg/Kg)
0 5
DE
PT
H (
cm)
0
100
SUB Edith
< 1960
< 1960
< 1960< 1960< 1960
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?
Need Cores?
• Better than before, but enough?– N = 11 from RMP/CEP + 2-5 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
Option 1: Repeat 2006 Effort
1. 10-11 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 sections4. Analyze up to 10 sections at ~10cm
(skipping) intervals (150-165 samples)PCBs, PBDEs, metals, TOC, grainsize
5. Total cost $350k+ ($300k in 2006)
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
Budget 2010, Two Bay Cores
Sample Collection & Processing $5,500
Laboratory Analysis $34,250
Radiodating 6600
PCBs, PBDEs 18750
Metals, Hg 6400
TOC, grainsize 2500
Proj Mgmnt, QC & Reporting $8,000
Total $47,750
+/- 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
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 Q’s
Nitty Gritty Details
• Example design to follow if desired
Siting Approach 2010+
• 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
Sampling Approach 2010+
• Unpowered (push/gravity/hammer) cores+ Low equipment needs/cost- Cores >1m deep may be difficult
Sectioning Approach 2010+
• 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
Analysis Approach 2010+
• 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)
Analysis Approach 2010+
• 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
Approach 2010+ 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
Dating: Bathymetric History
(USGS Bruce Jaffe)• Sum bathymetric
changes between surveys+ deposition – erosion
• Some sites depositional & erosional different periods
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
LSB001: Fast accumulation
~150cm to 1960 ~60cm to 1960
LSB002: Fast accumulation
~130cm to 1960 ~30cm to 1960
LSB Wetland Deposition
~80cm to 1960
Hg Analyses
• ICP-MS HF extract (CCSF) vs CVAFS aqua regia (MLML)CCSF vs. MLML Hg Concentration
CCSF
-0.5 0.0 0.5 1.0 1.5 2.0
MLM
L
-0.5
0.0
0.5
1.0
1.5
2.0
CCSF vs MLML Regression PlotOne:One
Lower South Bay 1960 = 30-60cm bay, 80cm C.Creek
LSB Metals
• Downcore concentrations noisy– Coyote Creek Hg max > Alviso!– Coyote Hg max @ 1960s depth (80cm)– Coyote Cu max @ 40cm = 1980s?
• ~max Cu discharge late 1970s (Palo Alto)
• ~surface sediment Cu USGS long term data
Conaway 2004 vs Current
5nmol/g ~ 1mg/kg
Lower South Bay PCBs
• PCB in bay cores max subsurface– LSB001 max @40cm
(60cm =1960)– LSB002 max @30cm
(30cm = 1960)
SB001: Continuous Erosion?
~0cm to 1960 ~15cm to 1960
Core ID: SB001, X: 564867.30345800000, Y: 4163027.619000000001858 depth: -1221898 depth: -1231931 depth: -1571956 depth: -1241983 depth: -1462005 depth: -1602006 depth: -161Reconstructed horizons: 0
SB002: No Change ~1950s
~0cm to 1960 ~12cm to 1960
SB Wetland Deposition
~30cm to 1960
South Bay Metals
• Downcore concentrations noisy– Cu max @ Greco Island similar to Coyote, but
into 1960s zone.– Greco Hg max ~uniform in wetland to 55cm =
1930s? (1960s Cs penetration to 30cm)
South Bay1960 = 12-15cm bay, 30cm wetland
Se Normalized to Percent Fines (mg/Kg)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
Greco Island SB001S SB002S RMP 5 Year Average
Hg Normalized to Percent Fines (mg/Kg)
0.0 0.2 0.4 0.6 0.8
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
Greco Island SB001S SB002S RMP 5 Year Average
Cu Normalized to Percent Fines (mg/Kg)
0 20 40 60 80 100
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
Greco Island SB001S SB002S RMP 5 Year Average
• PCB in bay max near surface– SB001 (continuous
erosion) at top ~5cm – SB002 (no change since
1950s) ~10cm
South Bay1960 = 12-15cm bay, 30cm wetland
CB001: No Change ~1940s
~0cm to 1960 ~5cm to 1960
CB002: Erosion to ~1920s
~0cm to 1960 ~20cm to 1960
CB006: Continuous Erosion
~0cm to 1960 ~12cm to 1960
Core ID: CB006A, X: 566290.21976900000, Y: 4174242.035890000001858 depth: -1061898 depth: -1341931 depth: -1321956 depth: -1831983 depth: -220Reconstructed horizons: 0
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, Cu @ surface,
60cm
Central Bay1960 = 5-20cm bay, ?? wetland
Se Normalized to Percent Fines (mg/Kg)
0.0 0.5 1.0 1.5 2.0 2.5
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
CB - CB001SCB - CB002SCB - CB006SACB - Damon SloughRMP 5 yr average
Hg Normalized to Percent Fines (mg/Kg)
0 2 4 6 8
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
CB - CB001SCB - CB002SCB - CB006SACB - Damon SloughRMP 5 yr average
Cu Normalized to Percent Fines (mg/Kg)
0 20 40 60 80 100 120 140 160 180
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
CB - CB001SCB - CB002SCB - CB006SACB - Damon SloughRMP 5 yr average
• PCB in bay max near surface– CB sites no change or
eroding
PCBs Normalized to Percent Fines (mg/Kg)
0.01 0.1 1 10 100
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
CB - CB001SCB - CB002SCB - CB006SACB - Damon SloughRMP 5 yr average
Central Bay PCBs1960 = 5-20cm bay, ?? wetland
SPB001: Erosion to ~1920s
~0cm to 1960 ~5cm to 1960
SPB002: Erosion to ~1880s
~0cm to 1960 ~2cm to 1960
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
San Pablo Bay1960= 2-5cm bay, ?? wetland
• PCB in bay max near surface– SPB sites eroding, no
reservoir
PCBs Normalized to Percent Fines (mg/Kg)
0.01 0.1 1 10
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
SPB - SPB001SSPB - SPB002SSPB - Wildcat MarshRMP 5 yr Average
San Pablo Bay PCBs1960= 2-5cm bay, ?? wetland
SU001: Erosion to ~1910s
~0cm to 1960 ~2cm to 1960
SU002: Erosion to ~1890s
~0cm to 1960 ~80cm to 1960?!!
Suisun Metals
• Hg highly variable @ Pt Edith and SU002– No dating for wetland cores yet
• SU002 max concentrations in top section– Hg, Se, Cu, subsurface spikes as well
Suisun Bay1960 = 2-80cm?! bay, ?? wetland
Se Normalized to Percent Fines (mg/Kg)
0 2 4 6 8 10D
epth
(cm
)
0
20
40
60
80
100
120
140
160
SU - Point EdithSU - SU001SASU - SU002SARMP 5 yr Average
Hg Normalized to Percent Fines (mg/Kg)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
SU - Point EdithSU - SU001SASU - SU002SARMP 5 yr Average
Cu Normalized to Percent Fines (mg/Kg)
0 200 400 600 800 1000 1200
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
SU - Point EdithSU - SU001SASU - SU002SARMP 5 yr Average
• PCB signal mixed– Bay sites erosional
according to bathymetry– SU002 mixed history
• (PCBs > RMP surface seds at 100cm)
Suisun Bay PCBs1960 = 2-80cm?! bay, ?? wetland
Hg Normalized to Percent Fines (mg/Kg)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Dep
th (
cm)
0
20
40
60
80
100
120
140
160
SU - Point EdithSU - SU001SASU - SU002SARMP 5 yr Average
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
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?)
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
Implications?
• Few ticking time bombs in Bay– So far, so good (2 of [90 + 11])– Largely WYSIWYG
• Surface ~ deeper for metals• Surface >~ deeper for PCBs
• Wetland cores capture historical pulses
• Historical loads mostly eroded, or already dispersed in Bay
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?