1. Environmental Due Diligence: Soil Vapor Intrusion Wednesday, May :00 p.m. - 1:00 p.m. Joseph G. Maternowski, Hessian & McKasy, PA Dana J. Wagner, Terracon Consultants, Inc.

2. Environmental Due Diligence- Vapor Intrusion
What is Vapor Intrusion and Why Do We Care?
II. Due Diligence Practices III. Risk and Liability Mitigation
Three areas of discussion today.

3. What is vapor and why do we care?
Volatile Organic Compounds (VOCs)
Releases to soil and groundwater
Migrate, Congregate and Infiltrate
Exposure to humans
VOCs used in mfg processes
Legacy impacts- vapor degreasing (Reed City, Michigan), septic systems (Evansville, IN), sanitary sewer (Brooklyn Center, MN), dry wells (Northeast Mpls)
Mixed use and residential development encroaching on former mfg sites with impacts
At Risk Populations- TCE- Women of Child bearing age. Day care and Residential use
Source: USEPA, 2011

4. What is vapor and why do we care?
Vapor intrusion is the transfer of a volatile organic compounds (VOCs) from releases to soil and groundwater and migration of vapors through the subsurface soil into a structure. Vapors typically follow preferential pathways such as cracks in walls and floors as well as other penetrations such as sewer lines and floor drains or other utilities.

5. II. Due Diligence Practices
Evaluation/Solution Path
Phase I ESA Identifies a REC/VEC
File review/desktop VI evaluation
LSI for vapor intrusion, as needed
Report, as needed
Vapor Mitigation, as needed
Typical scenario

6. II. Due Diligence Practices
Phase I Environmental Assessments
Using ASTM E and E
Identification of Recognized Environmental Conditions (RECs) from current or past on- or off-site industrial uses of hazardous substances and/or petroleum products which were released into the subsurface.
Evaluation of vapor encroachment/intrusion to the Site (buildings) from on- or off-site sources
Many potential sources to evaluate in some locations.
ASTM E Added “The movement of hazardous substances or petroleum products in any form, including, for example, solid and liquid at the surface or subsurface, and vapor in the subsurface,”  and requiring an analysis of surrounding property uses and data-base records for migration potential. 
E2600 : The Tier 1 screen even uses minimum search distances, focusing its analysis on potential petroleum releases within 1/10 of a mile from the target property, and up to 1/3 of a mile for hazardous material releases that migrate more easily than petroleum. 
Use critical distances in the ASTM E Vapor Encroachment Screening Standard to screen out VI concerns, to the extent appropriate:
Unless a Tier 1 screen can rule out a VEC, Guide 2600 calls for regulatory file reviews and/or soil, soil gas or groundwater sampling under a Tier 2 screen process
The critical distance is the lineal distance in any direction between the nearest edge of the contaminated plume and the nearest TP boundary, and is equal to 100 ft. for non-petroleum COC and petroleum LNAPL and 30 ft. for dissolved petroleum hydrocarbon COC.
Most consultants apply Tier 1 screen during Phase I ESA process to create technical basis for vapor decision making during Phase I ESA.

7. II. Due Diligence Practices
Example of Area where large plumes are affecting off-site commercial and residential properties.
Solvent release from disposal practices at former Henkel site led to a migrating solvent plume.
General Mills homes, tests, system installation.  Liability exposure due to Class Action filing. 
Source set well upgradient as well. General Mills made a technical argument – essentially through fingerprinting - that the TCE source was a different one.  Had upgradient well results that also pointed to another source(s). New site boundaries identified. 
Source: MPCA

8. II. Due Diligence Practices
St. Louis Park solvent plume and vapor intrusion site
MPCA will refer to EPA to cover large plumes.  St. Louis Park plume that affect large area.  Systems installed costs over $1M.  EPA pursuing cost recovery.
Source: MPCA

9. II. Due Diligence Practices
Type of Project- dictates approach and response
Sale
Acquisition
Refinance
Lease
Redevelopment
Lease Property- Concern with building and site causing concerns for operations and employee safety. Asbestos- BER but important if responsible as lessee.
Vapor- Private Equity acquisition- needed to respond to vapor concerns.
Sale- Understand issues which may impair deal- slow or result in cost and tail. Resolve prior to sale or acknowledge issues as part of deal. Clean environmental may enhance price and speed of deal.
Acquisition- Most traditional. Desire to preserve innocent landowner status. Identify issues which should be resolved prior to closing. Prepare for day when you will be seller.
Refinance- Lender has concerns with taking secured interest in property. Risk of foreclosure and having to sell property.
Redevelopment- Part of sale but proposed use to change so even though issues may have a No further Action letter, residual impacts will be excavated and need management or VMS may be needed due to changes to residential use. Significant costs.

10. II. Due Diligence Practices
Phase II May Be Required  
Assess RECs/VECs.
Determine relative extent and magnitude of releases.
Identify possible receptors.
Obtain sufficient data to assess materiality of issues.
Assist with cost opinion (pro forma) for acquisition and possible change in use including redevelopment.
Important to design Phase II to provide relevant information to accomplish deal goals.
Desire to limit but may short circuit higher confidence level.
Consultant should not a de facto arm of agency.
Anytime you test there is opportunity to find something. Seems obvious but never take testing lightly.
May create obligations not otherwise currently present.
Take Away: Fully evaluate with Consultant and counsel pros and cons of testing.

11. II. Due Diligence Practices
Vapor Intrusion Risk
Testing
Push Probe- Post Run Tubing (PRT)
Sub-slab
Indoor Air
Vapor Issues- very common in commercial practice these days.
Can result in delays in deal depending upon the situation. Test out requires paired sampling in heating and non-heating season. Heating November 1- March 31)
Can obligate landowner to take actions.
Take Away: Be prepared to deal with this.

12. II. Due Diligence Practices
Vapor Intrusion Risk
Sampling Depth and Influence of Building on Vapor Distribution (Non-Petroleum Compounds)
Rationale for conducting sub-slab testing.

13. II. Due Diligence Practices
How do we assess for vapors?
Push probe evaluations
Truck or track-mounted push probe rigs
Low-impact sampling
Typically for sampling outside the building footprint unless building operations allow space (i.e. garages, warehouse, etc.)
Fairly quick due to shallow sampling (upper 8 feet of soils and above water table)
Push Probe Evaluations
Less intrusive to building occupants, but does not replace need for sub-slab vapor sampling if issues noted.
Right of way testing used by MPCA to identify possible sources of vapors
Determine vapor cloud migration

14. II. Due Diligence Practices
How do we assess for vapors?
Sub-Slab Sampling- Vapor Pin
Using Cox Colvin Vapor Pin® or other sampling techniques
Used for sampling the lowest level of a building where the floor slab is in good condition (no large cracks or exposed soil)
Relatively quick means of sampling (“grab sample”)
Involves drilling a small hole through the floor slab to install the Vapor Pin®
Can be made permanent for other investigative uses
Additional sampling rounds
Pressure field extensions (measuring sub-slab air movement)
Post-mitigation monitoring
Sub-slab evaluations
Required under best management practice to establish whether or not mitigation is necessary.
BMP establish minimum amount if in program.
Can do less if just initial Phase II with understanding that more will be needed if issues.
BMP: If <33X ISVs- Heating (Nov-March) Non-heating (April-Oct)
BMP: If >33X ISVs but <33X EISVs- 2 Heating (Nov-March) 2 Non-heating (April-Oct) events
Should carefully evaluate locations.

15. II. Due Diligence Practices
How do we assess for vapors?
Indoor air evaluations
Not ideal in most cases
Not a primary evaluation tool
Longer sampling (8-24 hrs)
Return trip to collect samples
Better if used in conjunction with sub-slab testing (“paired sampling”)
Could identify compounds that we are not specifically looking for.
High potential for other background contaminants.
Sub-slab evaluations
Required under best management practice to establish whether or not mitigation is necessary where >33X ISV but <33X EISVs
2 Heating (Nov-March) and 2 Non-heating (April-Oct)
BMP establishes minimum amount paired sampling if in program.

16. II. Due Diligence Practices
How do we assess for vapors?
Indoor air evaluations- cont.
OSHA vs. ISVs
Sub-slab evaluations
OSHA standard for occupational exposures. Have EPCRA training.
ISVs for protection of general populations not subject to OSHA

17. II. Due Diligence Practices
Phase II Findings
Soil Vapor Impacts
Comparison to Risk Based Regulatory Standards
According to Land Use
Standards constantly evolving- primarily downward
Vapor Intrusion Risk is recent trend- Trichloroethylene (TCE) and Perchloroethene (PCE)
Context: Parts per billion- One drop of water in an Olympic size swimming pool- Or one mile on the way to Saturn…
Soil- SRVs and SLVs
Water- MCLs , HRLS and HBVs
Vapor- ISVs and 33X ISVs
Onsite is defined, confined and manageable (cost to cure).
Migration of GW and vapor impacts and 3rd Party Liability- major concern.
Lease Property- Vapor changed risk model. Need to account for it due to employee and/or tenant exposures.
TAKEAWAY: Account for impacts pre-closing or get solid indemnity. Know about vapor.

18. II. Due Diligence Practices
Phase II Findings
Risk Comparison Tools
Look Up Tables (ISVs, RSLs, State Defaults)
EPA VISL Calculator
Johnson Ettinger
HERO (CA)
Biovapor
Federal Guidance- July 2015
Available on EPA Vapor Intrusion Webpage (
Generally updated every 6 months (Jun./Nov.) with Regional Screening Level (RSL) updates
Simple and easy to use
Limited Inputs:
land use (residential or commercial)
carcinogenic risk (default = 1x10-6)
hazard quotient (default = 1.0)
average groundwater temperature (default = 25ºC)
Soil gas VISLs calculated by dividing air inhalation RSL by α of 0.03
Groundwater VISLs calculated using air inhalation RSL, α of 0.001, and Henry’s law constant for selected analytes.

19. II. Due Diligence Practices
Are Reporting Requirements Triggered?
Requires Technical and Legal Analysis  
Minn. Stat. §
UST Reporting
MPCA Guidance
Within 24 hours of discovery. Affecting waters of the State- broadly defined. Report by party in control of release- property owner.
UST-release- registered consultants required to report if impacts present during tank removals. May jeopardize Petrofund status.
Federal reporting. RQ- release above threshold in 24 hour period.
MPCA guidance- Vapor- exceedances of ISVs in soil gas. Enforceable?
TAKEAWAY: Sellers need to be careful about Phase II testing and obligations it may create.

20. II. Due Diligence Practices
Other Considerations
Access Agreements
Notification: Tenants, Employees and/or Residents 
Is there a “Responsible Party”?
Who Pays?
Business Owner in Commercial Settings
RP and MPCA/USEPA
Access Agreements: Allow MPCA access. Obtain access to others property.
Notification: Understand legal implications of data. Can cause panic if not handed properly.
Can be difficult to identify RP. May not be solvent.
Opportunity for cost recovery if RP can be located. Otherwise borne by business.

21. III. Risk and Liability Mitigation
Role of Minnesota Voluntary Programs
Should You Seek Assurances or Not?
Situational.
Commercial practice errs on getting assurances.
Sooner or later this issue will be sussed out.
TAKEAWAY: Consider deal and risks.

22. III. Risk and Liability Mitigation
Role of Minnesota Voluntary Programs
VIC Program- Non-Petroleum
No Association Determination
No Further Action Letter
Certificate of Completion
Off-site Source Determination
Approval of Response Action Plans and Implementation
Completion of Vapor Mitigation Response Actions
Completion of Vapor Assessment Action (When Mitigation Not Necessary)
Addresses MERLA liability.
Prospective NAD- Lender, buyer, operator
Retroactive NAD- full investigation, Affidavit
NFA vs. NA- Action taken
COC- Highest form of assurance. Not available to RPs.
Vapor Releases- new frontier. Vapor No Association requiring two rounds of sampling to confirm no actions.
Vapor only NAD- full investigation.
VMS or SSD- describe difference
Partial VMS
Vapor Response Letters
TAKEAWAY: Vapor big issue

23. III. Risk and Liability Mitigation
Role of Minnesota Voluntary Programs
Petroleum Brownfield Program
Tank and Non-Tank Closure
General Liability Letter
Tank Removal Verification
Approval of Development Response Action Plans
and Implementation
Reiteration of statute.
Closure confirmation
MPCA PB now uses Oct 2016 Guidance

24. III. Risk and Liability Mitigation
MPCA Updated VI BMP Guidance October 31, 2016
Collect soil gas and/or sub-slab samples if within 100 feet of known or suspected vapor sources
More sampling needed to ascertain no VI risk (>10,000 sf to <20,000 sf = 6 samples
Minimum two sample sets: heating and in non-heating season for VI risk determination
Applied 33X Intrusion Screening Values to determine further testing or mitigative actions
Established Expedited ISVs.
If exceedance of 33X EISVs need to undertake response actions within 30 days
Special measures for TCE and at-risk populations
Outlines residential and industrial commercial requirements to obtain assurances
BMPs- no rulemaking involved. Point of contention, but no change likely.
MPCA has Vapor Team which assist with guidance and outreach to community stakeholders

25. III. Risk and Liability Mitigation
From BMP Guidance

26. III. Risk and Liability Mitigation
From BMP Guidance

27. III. Risk and Liability Mitigation
Completion of vapor mitigation response actions for on-site buildings
III.   Risk and Liability Mitigation
MPCA Other Guidance
Partial Building Mitigation
>30,000 sf
Confirmation Sampling
Verification Sampling
Partial building- new guidance with MPCA Michigan has Big Building Model
Assurances cover those parties not otherwise responsible for the release and where vapor is the only concern.

28. III. Risk and Liability Mitigation
Vapor Intrusion Risk
Designed Mitigation- Sub-slab Depressurization
Sumps
Risers
Blowers
Verification Testing
Operation and Maintenance
Underground chemical vapors can migrate from the source of contamination through the soil and  building foundations into indoor air creating a health concern.
The primary goal of vapor intrusion work is to identify and address potential human health risks.
Effective public communication is an essential aspect of vapor intrusion work. This includes public awareness of health risks from vapor intrusion, vapor intrusion areas of concern, areas where mitigation has been installed and areas where more testing is needed.
Building mitigation decisions are based on current and future possibilities of a health risk from vapor intrusion.
Multiple factors contribute to variations in soil vapor contaminant levels.
Seasonal sampling from multiple sampling points are needed to determine there is no vapor intrusion risk.
The effectiveness of a mitigation system needs to be verified with confirmation testing.
Expedited action is needed when the data indicates the potential for a short-term health risk.
A plan is needed to assure continued operation of mitigation systems until data shows continued operation is no longer needed.
Future property owners need to be notified of the presence and need for continued operation of mitigation systems or unresolved vapor intrusion risks. 
When there is a source creating vapor contamination, the best practice is to remediate the source if feasible.
The obligation for addressing the possibility of vapor intrusion into a building and the source of the contamination are different for Superfund responsible parties compared to non-responsible voluntary parties and property owners.
A clear and predictable process is important for timely facilitation of property transactions.

29. Sub-Slab Depressurization
MPCA has draft guidance on partial mitigation.
Passive systems no longer acceptable.

30. III. Risk and Liability Mitigation
Vapor Intrusion Risk
Designed Mitigation- New Construction Vapor Mitigation System
Bedded Horizontal Runs
Spray Applied or Sheet Membrane
Risers
Blower
Verification Testing
Operations and Maintenance
MPCA has draft guidance on partial mitigation.
Passive systems no longer acceptable.
Addition of barrier.
Parking structures may be considered mitigative. Must prove so.

31. VMS- New Construction
Waffle system for pile-grade beam based foundation system.
As noted MPCA has draft guidance on partial mitigation.
For assurances passive systems no longer acceptable. Other states still consider.
Addition of sealed vapor barrier.
Parking structures may be considered mitigative. Must prove so.

32. III. Risk and Liability Mitigation
SE Hennepin Area. MPCA testing request to over 20 commercial property owners.  Note: Areawide, source investigation.  Commercial entitles are self-pay. No homeowners in this area but generally MPCA will look to PRP to pay for homeowners testing and system installation and State will cover costs if no viable PRP.  
Multiple sources. Difficult to sort out.  State testing in ROW.  MPCA currently packaging SE Hennepin Area for EPA referral.  Implications for PRPs and any party who has declined to conduct requested testing. 
Superfund list.  8 of 10 new sites added have vapor issues as their driver.
Commercial Building Owners:
Properties around Superfund area also affected,
Source: MPCA

33. Multi-family Apartment Complex
Transaction- 93 year old Complex
Indemnity/Escrow
MPCA and MDH Involvement
Design and install of SSD
Deed Record
Approvals/Closeout
A client was in the process of selling a portfolio of multi-family apartment sites which included two, 93-year-old, three-story with basement, 43-unit apartment buildings located in Minneapolis, Minnesota. A Limited Site Investigation (Phase II) was performed which identified VOC impacts to both groundwater and soil vapor at the site.
Most notably, tetrachloroethene (PCE) was detected in soil vapor beneath the building at concentrations well in excess of the residential MPCA Intrusion Screening Values (ISVs).
22 sumps between the two buildings
Over a dozen “open to ground” locations sealed
PFE conditions met throughout
Decrease in sub-slab VOC concentrations noted upon post-mitigation testing
No detections of VOCs in indoor air above the ISV
Cost of around $350,000 (consulting and contractor costs)
Regulatory assurance letters issued for the prior and new owner
No Action for vapor, No Association Determination, etc.
Operations and Maintenance (O&M) plan in place for the system for the life of the building
Building and its occupants protected

34. III. Risk and Liability Mitigation
Selected MPCA Vapor Weblinks:
Blaine: Crest Cleaners
Bloomington: Lyndale Avenue Corridor
Excelsior: Pure Oil Bulk Storage Facility
Minneapolis: 55th and Lyndale Avenue South
Minneapolis: Diamond Lake Rd. and Nicollet Ave.
Minneapolis: General Mills/Henkel Corp.
Minneapolis: Minnehaha Ave. and Snelling Ave.
Minneapolis: SE Hennepin Ave.

35. Questions? Dana J. Wagner Terracon Consultants, Inc. 763-489-3161
Joseph G. Maternowski
Hessian & McKasy, PA