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

9

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

8

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

}

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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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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32

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

34

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)

35

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

o, ... """'

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

40

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 finkel.ethan@epa.gov

Sarah White Community Involvement Coordinator (CIC) 617-918-1026 white.sarah@epa.gov

EPA Site Profile Page: http://www.epa.gov/superfund/walton

MassDEP Contacts:

David Buckley State Project Manager 617-556-1184 david.buckley@state.ma.us

42