EBC Site Remediation & Redevelopment Program:

Mass DEP Reopening

Old Trichloroethylene (TCE) Sites

Environmental Business Council of New England

Energy Environment Economy

Welcome

Jon Kitchen

Chair, EBC Site Remediation &

Redevelopment Committee

Senior Project Manager, Civil & Environmental Consultants, Inc.

Environmental Business Council of New England

Energy Environment Economy

Program Introduction & Overview

Ed Van Doren

Program Chair

Principal Environmental Engineer

CDM Smith

Environmental Business Council of New England

Energy Environment Economy

Checking In On Sites with Residual

TCE – Why & How

Paul Locke

Assistant Commissioner

Massachusetts Department of Environmental

Protection

Environmental Business Council of New England

Energy Environment Economy

The Legalities: Understanding How

MassDEP Can Reopen a Closed Site?

Elizabeth F. Mason

Attorney

McLane Middleton

Environmental Business Council of New England

Energy Environment Economy

Trichloroethene Vapor Intrusion Assessment

– Case Study for an Industrial Facility in

Massachusetts

Pamela O. Fahey

Senior Environmental Scientist

CDM Smith

November 2017

MassDEP Trichloroethene Vapor Intrusion Assessment

Case Study for Industrial Facility in Massachusetts

Pam Fahey

Erika Parsons

Ed Van Doren

Introduction

MassDEP contacted the facility due to a change in the TCE groundwater GW-2 standard.

MassDEP called the facility to discuss reopening of TCE sites and requested a vapor intrusion assessment of the facility and the adjacent residences.

MassDEP sent a letter identifying the facility as the site PRP

PRP was required to either perform an indoor air assessment or the MassDEP would do it.

8

TCE Standard Changes

9

Year Activity

1985-1987 EPA releases TCE toxicity values in IRIS – used by states to set groundwater standards to protect public health

1988 MassDEP develops TCE groundwater standard – 300 ppb

1989 EPA withdraws TCE toxicity values from IRIS due to uncertainty with scientific studies

2000 The site completes groundwater remediation, meets MassDEP standard of 300 ppb

2011 EPA releases new toxicity values, much lower than before, including new chronic RfC that is used to assess short term inhalation exposures

2014 MassDEP lowers TCE GW-2 groundwater standard – 5 ppb

2016 MassDEP searches database for all sites that had or have TCE levels greater than the new standard of 5 ppb

TCE in Residential and Workplace Indoor Air

10

Employee and Community Outreach/Risk Communications

CDM Smith met with local facility management group to bring them up to speed regarding the letter

Together we prepared and addressed three employee all hands meetings

The local facility manager and CDM Smith met with neighbors Letters with access agreements

Final letter with sampling summary

Local health agent also informed

11

Vapor Intrusion Assessment Activities

Sub-slab soil gas sampling and analysis

Indoor air sampling and analysis

Ambient air sampling and analysis

Interview with facility health and safety manager to inventory chemicals used in facility

MassDEP did not allow groundwater sampling as the only means of vapor intrusion assessment

12

Facility Sub-Slab Soil Gas Sampling

13

Facility indoor air sampling

14

Residential sub-slab soil gas and indoor air sampling

15

Challenges associated with the residential evaluations

Very old structures 1735 to mid 1800s.

Dirt and concrete floors.

Multi-level living spaces.

Storage of consumer chemical products.

16

Facility Assessment Results Soil Gas: TCE was detected in CDM-SG-4 at 1,730 µg/m3,

greater than C/I screening level of 120 µg/m3

Indoor Air: TCE was not detected in any indoor air samples Secure building foundation

HVAC system

Trans-1,2-DCE Detected in soil gas CDM-SG-3 at 3,810 µg/m3 , greater than C/I

screening level of 3,700 µg/m3

Detected in all indoor air samples (252 µg/m3 to 5,000 µg/m3)

C/I indoor air screening level is 53 µg/m3

Disclosed prior to sampling that it is in a degreaser used at the facility 17

Residential Assessment Results

TCE was not detected in indoor air at any residence – NO VI

Carbon tetrachloride detected in each home at or slightly above residential limit of 0.54 µg/m3 (background-based value) Non-detect in all subsurface soil gas samples Present in ambient air at 0.554 µg/m3

Residential concentrations ranged from 0.554 µg/m3 to 0.749 µg/m3

Residential Basement Basement full of paints, solvents, sprays 1,1,1-TCA detected in basement at 12 µg/m3 (limit is 3 µg/m3)

Likely impacting first floor (1.31 µg/m3), subsurface (3.09 µg/m3), sub-slab (5.67 µg/m3)

18

Conclusions and Follow-up

Additional indoor air sampling event completed at facility in winter 2017 MassDEP agreed to only indoor air sampling at the facility No additional sub-slab soil gas sampling

No vapor intrusion at residences

No additional sampling at the residences

Abandonment of sub-slab soil gas sampling points at the residences in fall 2016 and at the facility in the spring 2017

19

Reports and Submittals

Submitted scopes of work for MassDEP review.

MassDEP rejected proposed groundwater sampling

Focus solely on indoor air concentrations

Complete report with results of sub-slab soil gas and indoor air sampling and assessment.

Individual letters to each of the home owners with each with laboratory results and a summary table.

No final written approval expected from MassDEP.

20

Project Management

Work was performed by the PRP MassDEP required initial sampling be completed within 60

days of initial letter

CDM Smith prepared Work Plan, communications, sampling and reporting

Direct communication with local facility management

Corporate communications support

21

Regulatory Environment

Massachusetts Contingency Plan (MCP)/Licensed Site Professional (LSP) compliance and support

Current Status under the MCP

22

Environmental Business Council of New England

Energy Environment Economy

Vapor Intrusion or How I Learned to

Stop Worrying and Love Indoor Air

Julianna Connolly & Todd Creamer

Geosyntec Consultants

Vapor Intrusion or: How I Learned to Stop

Worrying and Love Indoor Air

Julianna Connolly, LSP & Todd N. Creamer Boston, MA | 02 November 2017

25

TCE Sites & the MCP

Residential Commercial

No Significant Risk

2 µg/m3

8.8 µg/m3

Imminent Hazard – Women (pregnant or who may become pregnant)

>6 µg/m3

>24 µg/m3

Imminent Hazard – All Receptors

>20 µg/m3

>80 µg/m3

• risk-based concentrations are low

• No Significant Risk & Imminent Hazard concentrations are similar

• harder to close TCE sites with active vapor intrusion mitigation

• shutdown tests are important & often misunderstood

TCE Screening Levels from 25 US Jurisdictions

26

Common Management Strategy

Sample:

• Indoor air

• Sub-slab soil gas

Get confusing result

Sample again

27

Recommended Management Strategy

1. Exposure Assessment

2. Risk Communication

3. Timely Mitigation

28

Tell a Coherent Story

1. Exposure Assessment

2. Risk Communication

3. Timely Mitigation

29

Temporal & Season Variability: Building Pressure Control

30

Spatial Variability in Large Buildings

100 ft

Site investigation plan

31

Managing Spatial Variability: High Volume Sub-slab Sampling (HVS)

Fan or Vacuum

Sample Port

Extraction Point

Lung Box

32

Generalized CSMs for HVS

33

Background Sources

34

Distinguishing Background from VI: Field Methods

All are best when used to test

specific CSM hypotheses.

35

Satisfying to stakeholders when

you can ID a source.

Distinguishing Background from VI: Office Method

36

1.E-03

1.E-02

1.E-01

1.E+00

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05

Att

en

ua

tio

n F

ac

tor

Subslab Soil Gas Concentration (ug/m3)

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+00 1.E+01 1.E+02 1.E+03A

tte

nu

ati

on

Fa

cto

r

Subslab Soil Gas Concentration (ug/m3)

TCE

111TCA

PCE

cis12DCE

11DCA

11DCE

PCE

111TCA

TCE

FREON

1. Exposure Assessment

2. Risk Communication

3. Timely Mitigation

37

• Meet with stakeholders

• Listen

• Newsletter

• Website

• Phone hotline

• Listen

• Develop a plan

Management Strategy

1. Exposure Assessment

2. Risk Communication

3. Timely Mitigation

38

Management Strategy

Rapid Response Indoor Air Treatment

• Remove ~10-50% of VOCs

• Occupants report “fresher air”

• ~$1000 each

• Quiet fan

• Low electric consumption

• Carbon life weeks – couple years

• ~300-600 cfm:

– IAExch 4-48/day

Sources:

www.austinair.com

http://amaircare.com

www.airpura.com

www.allerair.com

39

Timely Mitigation

HVAC systems

• Added makeup air

• Pressure manipulation

• Watch for re-entrainment

40

• Use existing infrastructure

Targeted Mitigation is More Timely

100 ft

Conceptual mitigation

plan

41

Summary

1. Exposure Assessment

2. Risk Communication

3. Timely Mitigation

42

1. Tell Coherent Story

– Manage temporal & spatial variability

– Background sources

2. Meet, Listen, Outreach

3. Timely Mitigation

– Carbon units

– HVAC mods

– Use existing infrastructure

– Targeted SS venting

EBC Site Remediation & Redevelopment Program:

Mass DEP Reopening

Old Trichloroethylene (TCE) Sites