Walton and Lonsbury, Inc.
Superfund Site
EPA Public Information Meeting May 7, 2018
Attleboro Public Library
5/7/2018 1
Introductions
U.S. EPA
Ethan Finkel – Remedial Project Manager (RPM)
Sarah White – Community Involvement Coordinator (CIC)
Daniel Keefe – Superfund Section Chief
MassDEP
Dave Buckley – State Project Manager
EPA Contractor (AECOM)
Barbara Weir – Project Manager
Diane Silverman (TRC Solutions) – Project Human Health Risk Assessor
Agenda
Background Information
Remedial Investigation
Treatability Study
Feasibility Study
What’s Ahead
Q&A
Background
• Walton & Lonsbury (W&L) Operational History
• Contaminants
• EPA Removal Program
• EPA Remedial Program
Site History • Walton & Lonsbury operated a
chromium electroplating facility from 1940 to 2007
• Waste management practices during years of operation included: • Direct waste (“back door”) discharge
to abutting southern wetlands (ceased in 1970)
• Surface impoundment and lagoon (ceased in 1984)
• Underground and above-ground storage tanks
• Dry well
• Resulted in contaminated soils, sediment, surface water, groundwater, and indoor air
Walton & Lonsbury Facility
Brookside Apartments
Contaminants • Waste generated and associated with chromium electroplating include:
• Metals – chromic acid, chromic oxides • Solvents used as parts degreasers: volatile organic compounds (VOCs) – TCE, 1,1,1-
TCA) • Spent acid solution
• Primary site contaminants are chromium and trichloroethylene (TCE) • Chromium exists in different “forms” (oxidation states)
• Hexavalent chromium (Cr+6, Cr(VI), chromium(VI)) is very different from trivalent chromium (Cr+3, Cr(III), chromium(III)) • Cr(VI) more water soluble, more reactive, more toxic • Cr(III) much less toxic, essential element in humans
• “Total” chromium – accounts for both hexavalent and trivalent forms
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8
EPA “Removal Program” – Removal Action
Removal action (Oct 2010) to mitigate ongoing human health exposure to impacted soil and groundwater
• Removal of W&L buildings and residual waste materials
• Excavation and off-site disposal of contaminated sediment from southern wetland
• Building floor slab, cobble-filled pit, trenches, etc. remain at site
• Focus of efforts shifted east to residential areas
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Removal Action (cont.)
• Construction of an engineered cover to prevent upwelling of groundwater and isolate surficial soils adjacent to Bliss Brook (behind residential areas)
• Construction/installation of a permeable reactive barrier (PRB) wall upgradient to Bliss Brook to intercept groundwater discharge (reduce Cr+6 to Cr+3)
EPA Remedial Program
• Walton & Lonsbury site added to the National Priorities List (NPL) in May 2013 – “Superfund” site designation
• No viable “responsible party” to conduct environmental testing or cleanup operations • Owners/operators – deceased; • Financial inability of survivors; and • No corporate entity to “order” the cleanup
• Designation as “Superfund” site allows for government-funded cleanup
125 250 000 ---===----•Feet
, inch = 250 feet
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EPA Remedial vs. Removal Programs
• Removal program deals with acute or shorter term risks (i.e., emergency, time-critical or non-time critical actions)
• Remedial program deals with the residual or chronic risks (exposure over longer periods of time) • Iterative approach to determine the nature
and extent of contamination – what are the contaminants, how and where do they interact with the environment
Removal
Remedial
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Remedial Program – Milestones
• Remedial Investigation (RI) – how bad is it? • Investigate the nature and extent of contamination • Human Health Risk Assessment Evaluation of current/future risks
based on site investigations • Ecological Risk Assessment
• Feasibility Study (FS) – what cleanup options exist? • Analysis and evaluation of cleanup alternatives
• EPA Proposed Plan – what EPA thinks is the best alternative(s) • Protectiveness, compliance with state, federal, local laws • Short- and long-term effectiveness, cost, implementability, reduction in
toxicity, mobility, and volume • State and community acceptance
Remedial Program – Milestones (cont.)
• Record of Decision (ROD) • Documents and memorializes final selected remedy
• Remedial Design (RD) • Design of the selected remedy
• More specific details as to how the remedy will be built and constructed
• Remedial Action (RA) • The cleanup itself
• Dependent upon construction funding
Remedial Investigation (RI) – Phased Approach
• Phase 1 (Jun 2014 – Aug 2014) • Collect soil and sediment samples, install monitoring wells into bedrock, sample surface water
and groundwater
• Phase 2 (Oct 2014 – Mar 2015) • Install additional wells, collect more samples of soil, sediment, surface water, and groundwater • Sample air beneath (sub-slab) and within (indoor) homes over or near TCE groundwater plume
• Phase 3 (Jul 2015 – May 2016) • Focused investigation of bedrock groundwater plume – how deep into rock do contaminants go?
• Focused investigation of sediment – toxicity tests and pore water sampling
• Phase 4 (Oct 2016 – Dec 2016) • Focused investigation of soil toxicity (ecological risks)
• Earthworm survival and contaminant bioaccumulation
• Seedling germination
RI – Phased Approach (cont.)
• Draft RI Report (Jun 2016) • Identify data gaps from previous phases
• Phase 5 (Nov 2017 – Jan 2018) • Updated EPA guidance – collect and analyze soil samples for lead testing
• Surface water and groundwater sampling and surveying
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SURFACE AND SUBSURFACE SOIL SAMPLE LOCATION PLAN
• •
Surface and Subsurface Soil Sample Locations
Historic Sample Location
New Sample Location
• FARMERS
POND
SEDIMENT SAMPLE LOCATION PLAN
• •
Sediment and Surface Water Sample Locations
Historic Sample Location
New Sample Location
WALTON"''
f BUNGAY
RIVER
MONITORING WELL LOCATION PLAN
• • fl~A.Q
JI ' H" {.:J;..
~1 1-.,
Groundwater Sample Locations
Historic Monitoring Well
New Monitoring Well
WALTON ST
Total Chromium Concentration Range (mg/kg)
• <= 16
• • •
>16 -1 ,000
>1,000 - 5,000
>5,000 SURFACE SOIL TOTAL CHROMIUM
CONCENTRATION RANGES
WALTON ST
Hexavalent Chromium Concentration Range (mg/kg)
• • •
Not Detected or Detected <0.2
>0.2 - 100
>100
BUNGAY RIVER
SURFACE SOIL HEXAVALENT CHROMIUM CONCENTRATION RANGES
RI Phases – Results Total vs. Hex Chrome
FARMERS
POND t
Total Chromium Concentration Ranges (mg/kg)
• <=23
• >23-1000
• >1000 - 5000
• >5000
-" SEDIMENT TOTAL CHROMIUM CONCENTATIONS
Total Chromium in Sediment
• Highest in Southern Wetland where Walton & Lonsbury discharged waste
• Concentrations detected above reference samples found as far south as Mechanics Pond • High total chromium not
necessarily indicative of high hexavalent chromium
• Toxicity tests on sediment showed no toxicity, regardless of chromium concentrations
ST
• AECOM Surface Water Sample
HEXAVALENT CHROMIUM* IN SURFACE WATER
FALL 2014
• Field filtered results, label units are µg/L Hexavalent Chromium in Surface Water
• Detected in Bliss Brook
• Highest concentrations between SD-210 and SD-212
• Shallow groundwater plume discharging to this area of Bliss Brook
• Toxicity test results showed toxicity to water fleas at SD-210 and SD-212
3 GROUNDWATER RESULTS FOR HEXAVALENT
CHROMIUM IN OVERBURDEN (µg/L)
Hexavalent Chromium in Overburden Groundwater
• Plume extends from Walton & Lonsbury property to Bliss Brook
• Shallow overburden groundwater discharges into Bliss Brook
• Deep overburden groundwater passes underneath Bliss Brook
• Total chromium concentrations are similar to hexavalent chromium (Cr is all in Cr(VI) form)
• Permeable reactive barrier wall has some effect in reducing toxic Cr(VI) to less toxic Cr(III)
Si
Total Chromium Concentration Ranges
in Surface Soil and Sediment (mg/kg)
• <=RME Reference Sample Concentration
• >RME Reference Sample Concentration - 1000
• >1,000 - 5,000
• >5,000
--- Hexavalent Chromium Concentration, µg/L
GENERALIZED EXTENT OF CHROMIUM CONTAMINATION
Summary of Chromium Results
• Contamination found in Southern Wetland a result of direct discharge from the Walton & Lonsbury facility
• Contamination in Bliss Brook due to discharge of shallow groundwater to surface water
• Contamination moves downstream and is transported through water and on soil particles
3 GROUNDWATER RESULTS FOR TCE
IN OVERBURDEN (µg/L)
TCE in Overburden Groundwater
• TCE plume is slightly south of chromium plume – waste and disposal practices occurred at different areas of the Walton & Lonsbury property
• Several properties overlying TCE contamination plume
• Evaluation for potential vapor intrusion
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vapor intrusion throug cracks in found ion sl
water table
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roundwat r plume of voes
Vapor Intrusion
• Migration of vapor-forming chemicals (volatile organic compounds, such as TCE) from any subsurface source into an overlying building
• VOC-contaminated groundwater volatilization soil vapor migration vapor intrusion via cracks in building foundation slab
***
D
INDOOR AIR SAMPLE LOCATION PLAN
NOVEMBER 2016
Legend
-- Bliss 8100k
--PRB Groundwatltf Treatment Trench
Grounct«ate, Collection Pipe
D Former BuHd!ng F001prln1
[=1 &cavabon Extent
~ l.Jmit of Cap Installed by Removal Program
1111 umil of Clos.d Lagoon Area
Combined Wotl.1nds
E:::J Emergent/Open Water Wetland
~ Foras1ed/Sh1ub Welland
1111 Open Water
• Home not umpled clue to Jn&ence of SSOS. •• Home not wmpi.o beclUM c iubanclonMI ··•Aocnaforwmplingnotw-nted
0 AECOM 50
1·1,200
100 200 Feet
Testing for Vapor Intrusion • Phase 2 (2015) sampling event
• Sub-slab vapor and indoor air sampling
• SUMMA canisters – 24-hour tests
Vapor Intrusion Testing – Results
• Properties near or overlying groundwater plume were sampled (sub-slab soil gas and indoor air) • No detection or low detection below health-based screening levels
• No unacceptable risks no mitigation system required
• Properties with existing vapor mitigation systems tested to ensure functioning as intended (i.e., creating negative pressure differential) • All systems (sub-slab depressurization systems, SSDS) functioning as designed
• Periodic testing may be warranted
Surface Water and Sediment Toxicity Tests • More reliable method than a comparison of results to literature values
• Conducted using site-specific samples to directly measure toxicity and environmental risks
Surface water – 1 species Sediment – 2 species • Ceriopaphnia dubia (water flea) • Hyalella azteca (amphipod)
• Chironomus dilutus (midgefly) Measurement endpoints: • Survival Measurement endpoints: • Reproduction • Survival
• Biomass
ST
• AECOM Surface Water Sample
HEXAVALENT CHROMIUM* IN SURFACE WATER
FALL 2014
• Field filtered results, label units are µg/L
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~ 40 .0 0 41 z 'o 30 .0 .. 41
..0 E ~ 20 .0 41 Cl Ill
~ 10.0 <
00
>-
-
Figure 18. Average Brooder Reproduction for 6-Day C. dubia Walton & Lonsbury Surface Water Toxicity Test
Southern Wetland Bungay R. Bliss Brook
Mechanics Pond/
-- - -
f-- -- ~
~
f-- - -- - f-- >->--- -
~ - -- - ~ -~ -
240' 20 1 205 220· 305 312 207' 212 210 218
Sample Location
• Reference location
120 "ii > 100 ·s; :i 8 0)
.#- 60
40
20
0
Figl:llre 1A. Pe1rcent Survival for 6-Daiy C. ,dr.,bia Waltcm & Lo1nslbury Surface Wa-teir Toxicity Testing
240.. 201
Mech nics Pondl/ Bun ,1 R. Pili ,<; Pinnol:
200 220'" 305 312 2or 212 210 218
Sam pie L,o,caliom
• Flefereocg loca!iollS
Surface Water Toxicity Test Results
POND t
Total Chromium Concentration Ranges (mg/kg)
• <=23
• >23-1000
• >1000 - 5000
• >5000 SEDIMENT TOTAL
CHROMIUM CONCENTATIONS
Figure 1. Summary of H. azteca survival
120_ 0 ____ Mechanics _____ ---------.. ·-· ... .. . ···----·-Pond/Bungay River Southern Wetland
100.0
,.-,.
20.0 ~
····---·-------Bliss Brook
* = significant differenc~ when compared to associated reference
Figure 4. Summary of C. dilutus Average Surviva
120.0 Mechanics
··-p-o-n-d/_B_u_n_g_a_y _____________ ~-----Southem Wetland
River 100.0 ----------------- -------· . ·-- -
l 80.0 1:i :>
"! :I 60.0 "' <II
f! 40.0 <II
:,, <=:
20.0
Sample location
Bliss Brook
Sediment Toxicity Test Results
Additional Toxicity Testing • Phase 4 – Conducted to eliminate uncertainty about ecological risks at
Southern Wetland and Bliss Brook • Few literature values (benchmarks for acceptable concentrations of chromium)
• Direct measure of potential risk to chromium
Invertebrates – earthworm survival rates and chromium uptake Aquatic vegetation – seedling germination and root elongation
14-day exposure period and measurement endpoint, 100% survival 28-day exposure period and percent emergence and survival endpoints, 95% emergence and 100% survival
Two water resource protection districts within City of Attleboro
• Orrs Pond • Bungay River
Portion of the Bungay River protection district extends into site review area
“Medium” Use & Value determination for groundwater (within the protection district) as a potential future drinking water source
Evaluate cleanup options to restore groundwater to its beneficial use as a potential future drinking water supply
Groundwater Use & Value Determination
.. Ofl'!O OEP-SS
PHASE 3 GROUNDWATER RESULTS FOR HEXAVAL Cl IRO I • I BEDROCK
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A ~oasSoi • Residential
• Wetland Soll ;th Potential RiSk orth Ave. (CIF) E,posure M•::.:tielYerds . West of ~ oil (Fl [Z] Sol 11 Res Surface/Subsulfac:e [ZJ W&L Property
_ St reams . Footpnnt
CIFonner Buid~nf ,am CJExcavatiOn ~ 1a11ed by Removal Prog r:::sa Umlt of Cap Area
Limit or Closed Lagoon
~ ml>ned Wetland~ ferWel1and
0 Emergen~;Wetlar'ld G:!I F«ested/S
- Open Water OOXionlD
S0-601: P':'3s:a1 ~=p~~ion (< 150µm): Total Leed l"I ' >200mg.4'.g
<2oomg/kg
C= Current F : FUute
J:71 155 NE.!!..,THAVE
5l NORTH AVE
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Updated EPA Lead Guidance
• Updated EPA guidance for evaluation of fine fraction (<150 μm) lead in soil
• Portion of lead in soil more representative of exposure • Previous sampling evaluated “coarse” fraction
• Phase 5 (Dec 2017) data collection from 4 exposure point areas:
• Residential area west of North Ave
• Residential area east of North Ave • Wetland surface soil at the Southern Wetland
• Wetland surface soil at Bliss Brook
• Perform in-vitro bioavailability (IVBA) lead analysis to determine site-specific bioavailability of lead in soil
• Evaluate risks to lead in soil using site-specific data
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Areas of Actionable Risk
W&L Property: Surface/Subsurface soils,
Shallow Groundwater
Bliss Brook: Surface Water
Site-Wide Groundwater: tap, irrigation, indoor air
Residential Yards West of North Ave:
Surface/wetland soils
Treatability Studies
• Evaluate feasibility of treatment of hexavalent chromium • Soil, overburden groundwater, and bedrock
groundwater
• Identify treatment reagents that are effective for each contaminated medium • Calcium Polysulfide (CaSx), Micro-scale zero valent iron
(ZVI), FerroBlack-H (FB-H), MRC
• Provide basis for estimating cost of hexavalent chromium treatment
• Titration testing followed by series of bucket tests
• Each treatment reagent blended with site soils and groundwater
• Effective treatment = removal of 90% Cr+6, total Cr
• Reagents with favorable results retained for further testing (e.g., additional metals, VOCs)
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Re g,ent
!=et ro91aa. (FeS suspension wilh ree su ide (NeSH)l
MRC (orgatlO&ulf,ur esterJipol:Ylactate)
Calcium fl'otysu 11d
(CaSx)
sarety
2S g:enern1!Joii atlow :PH .i conoem1•
Ev.ilu.i e during bn.cht t
Must oid acidic conditions
!::)(oellent ·sli.01t.term, xce'llen lon,g-terrn
Med1um'lo good
Shoukl pr11,1ide sho •t rmtr atment and !ong•'lerm bio tJeatm n
Good ·sho1Me.rm tJ atrmn , long-te m tre· lmen ie:s on na ·ve iron, may ool be s ,effecwe as Ferro ck
Mob' e ftacf on (Na.SH) p~ible tm.piilct kl S\nf~ce water. pH may be elev ed. al a during1 nch l@S
No e identified
H. :hlly mobile and d p, eel ro or, may itll)ac stonnwater, avoid use · ear stream
Cost
Mechum $550/ton
High $700/ton
Medium
Medium $500/ton
Othe:r ot·entlal Benefits
Very effec1Ne for As, 1, Pb .ind other multwa nt rnetars E:ffecil,;en on TCE 111nknoi,,,m
W I a:s.o I at voes
Ea orln S tu nje,ction,
Su,speneion of iron r;,.il1fcle5,, relatively difficult to creale 1.1111/onn d1str1b:ut!on
Mayb diffcu o get good diWi bulion
Mod:erat:e to difft::u o, injed: and ob· ·n unifoim d'istributio:n .
High ly mobile, easy toinj easo.:i plugging of wells possible,
10.000
Figure 3-1
Cr+6 Testing Resu lts fo r Overburden Grou ndw at er
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Figu re3-2
Tota l Cr Test ing Resu lts fo r Overburden Groun dw ater
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Treatability Studies – Conclusions Overburden Groundwater • ZVI most effective in reducing Cr+6, and (>95%) total Cr removal • FB-H also effective in reducing Cr+6, and moderate (between 30-90%) total Cr removal • CaSx effective in reducing Cr+6, but less effective for total Cr • MRC very effective in reducing Cr+6 (>99%), but very high total Cr concentration results
Bedrock Groundwater • FB-H (most feasible reagent for bedrock GW) effective in reducing Cr+6 and total Cr
Unsaturated Soil • FB-H effective in treating site soil (92% Cr+6 removal) • ZVI may also be effective (addition of water likely necessary)
36
Feasibility Study – (General) Remedy Alternatives
• No Action (required by statute)
• Limited Action (e.g., monitoring, access or use restrictions)
• Containment (e.g., capping/covering waste in place, vapor
mitigation system)
• Removal (e.g., excavation and off-site treatment/disposal)
• Treatment: In-situ (e.g., permeable reactive barrier, chemical
reduction/oxidation)
• Treatment: Ex-situ (e.g., groundwater pump and treat system) 37
Site Institutional Controls (ICs)
• Non-engineered instruments, such as administrative and legal controls, that help to minimize the potential for exposure to contamination
• Ensure protectiveness of cleanup actions where residual contamination might be left in place
• Potential Site ICs: • Property restrictions (e.g., vapor mitigation systems, engineered cover) • Walton & Lonsbury property (prohibit certain future uses) • Groundwater use (e.g., prevent well installation, withdrawal)
38
Feasibility Study – Evaluate Options
Nine Criteria Evaluation
Threshold Overall protection of human health and environment Compliance with ARARs (State and Federal Laws)
Balancing Long-term effectiveness and permanence Reduction of toxicity, mobility, volume Short-term effectiveness Implementability Cost
Modifying (evaluated after release of Proposed Plan)
State Acceptance Community Acceptance
What’s Ahead – 2018
• Finalize the Remedial Investigation • Human Health Risk Evaluation
• Ecological Risk Assessment
• Prepare Feasibility Study • Detailed Analysis of Remedial Alternatives
• Release Proposed Plan (September) • Solicit community and state feedback/acceptance
• Hold public hearing
• 30-day public comment period
• Responsiveness Summary to address comments
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What’s Ahead (cont.)
• EPA signs Record of Decision (December) • Memorializes final selected cleanup remedy
• Remedial Design (RD) • Design of the selected remedy
• More specific details as to how the remedy will be built and constructed
• Remedial Action (RA) • The cleanup itself
• Dependent upon construction funding
41
Questions?
EPA Contacts:
Ethan Finkel Remedial Project Manager (RPM) 617-918-1293 [email protected]
Sarah White Community Involvement Coordinator (CIC) 617-918-1026 [email protected]
EPA Site Profile Page: http://www.epa.gov/superfund/walton
MassDEP Contacts:
David Buckley State Project Manager 617-556-1184 [email protected]
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