Environmental Due Diligence and Targeted Site Sampling
Targeted soil, groundwater and vapor sampling used to investigate recognized environmental conditions, suspected releases, underground storage tanks and other property-specific environmental concerns.
Site-Specific Environmental Investigation
A Phase II Environmental Site Assessment is a site-specific investigation used to determine whether contamination is present in selected areas or environmental media. It commonly follows a Phase I ESA that identifies a recognized environmental condition or another concern requiring physical data.
Unlike a Phase I ESA, which relies primarily on records review, historical research, interviews and site reconnaissance, a Phase II ESA generally involves targeted sampling and laboratory analysis. Depending on the concern, samples may include soil, groundwater, soil vapor, sub-slab vapor, indoor air or other media.
The scope should be developed from the property's history, suspected source, conceptual migration pathways and the decision the client, lender, attorney or other project participant needs to make.
Environmental Due Diligence Stages
A Phase I identifies potential environmental concerns. A Phase II uses targeted field investigation and analytical data to evaluate selected concerns.
Primary question: Are there recognized environmental conditions or other concerns that warrant further evaluation?
Primary question: Is contamination present in the selected media and areas of concern that were investigated?
Common Environmental Concerns
Sampling locations and analytical parameters should be selected from the Phase I findings, site history, suspected source, property layout, transaction objective and applicable jurisdiction.
Fuel dispensing, tanks, piping and petroleum handling may warrant soil, groundwater or vapor investigation.
Chlorinated solvents and other volatile chemicals may create soil, groundwater and vapor-intrusion concerns.
Waste oil, solvents, drains, chemical storage, hydraulic equipment and historic operations may create source areas.
Known or suspected tanks, petroleum odors, stained soil or incomplete closure records may warrant targeted testing.
Vapor-forming contaminants in soil or groundwater may migrate toward an occupied building.
Buyers, sellers, lenders, attorneys and investors may request sampling before acquisition, refinancing or redevelopment.
Targeted Environmental Media Sampling
The field program is selected for the recognized environmental condition and the environmental media that can answer the project question.
Soil samples may be collected near tanks, former operations, stained soil, drains, chemical-storage locations or other suspected source areas.
Groundwater may be evaluated where petroleum impacts, solvent migration or other subsurface contamination could affect groundwater.
Vapor samples may be used to investigate vapor-forming contaminants in the subsurface and potential migration toward occupied buildings.
Air samples may be incorporated into a vapor-intrusion evaluation together with a building survey and review of indoor chemical sources.
View indoor air testingGeophysical screening may help evaluate suspected tanks or buried features, followed by targeted environmental sampling when warranted.
View UST servicesSample handling, analytical methods, QA/QC, data review, figures, interpretation, limitations and recommended next steps are documented as scoped.
Site-History-Based Analytical Testing
Analytical parameters should be selected from the former site uses, suspected releases, environmental media, regulatory requirements and project objective.
Solvents, dry-cleaning chemicals, fuel-related compounds and other volatile contaminants.
Gasoline, fuel oil, diesel, waste oil and petroleum-related compounds associated with tanks and vehicle operations.
Semi-volatile compounds associated with petroleum, historic fill, combustion and selected industrial uses.
Lead, arsenic, mercury, chromium, cadmium, nickel and other metals selected from site history and media.
PCB analysis may be appropriate for selected electrical, manufacturing, hydraulic-fluid or historic industrial concerns.
Agricultural, landscaping, pest-control, storage or manufacturing history may warrant selected pesticide analysis.
Subsurface Source-Area Investigation
Soil and groundwater samples may be used to evaluate whether contaminants are present near a suspected source or beneath a property. Sample locations should be based on the environmental concern, historic use, field observations and the conceptual understanding of potential contaminant migration.
Soil Vapor, Sub-Slab Vapor and Indoor Air
Vapor intrusion can occur when volatile chemicals migrate from a subsurface source toward a building and enter through cracks, utility penetrations, sumps, floor drains or other openings.
A vapor-intrusion investigation may include soil vapor, sub-slab vapor, indoor air and outdoor air samples. Building surveys and review of indoor chemical sources are important because indoor products and activities can influence air-sample results.
Heating Oil, Gasoline and Petroleum Releases
Known or suspected underground tanks can affect property transactions, redevelopment and environmental liability. A Phase II scope may incorporate tank-location information, geophysical findings, soil observations and targeted soil, groundwater or vapor sampling.
View Underground Storage Tank ServicesDefine the Purpose Before Fieldwork
The project objective controls the amount of sampling, documentation and follow-up investigation that may be necessary.
Focused sampling designed to address selected buyer, seller, lender or attorney questions.
Sampling used to determine whether selected contaminants are present in suspected source areas or media.
Additional investigation designed to evaluate the horizontal or vertical extent of confirmed impacts.
Agency-directed work may require specific work plans, methods, notifications, reporting and qualified professionals.
From Environmental Concern to Written Findings
Review Phase I findings, site history, prior reports, maps, records and the transaction objective.
Select areas, environmental media, depths, analytes, methods and QA/QC needs for the question being investigated.
Coordinate access, utilities and specialty subcontractors and collect the environmental samples included in the scope.
Submit samples to qualified laboratories and evaluate results with locations, depths, site history and selected criteria.
Document methods, results, interpretation, assumptions, limitations and recommended next steps when warranted.
Environmental Due-Diligence Documentation
The report format depends on the investigation objective, number of samples, regulatory context and agreed scope.
Real Estate, Redevelopment and Property Management
Closely Related Environmental Services
Official Technical Resources
Phase II due diligence and regulatory investigations are different scopes. The applicable standards and agency guidance depend on the project purpose and jurisdiction.
Current ASTM practice for the Phase II Environmental Site Assessment process.
Open ASTM resource EPAEPA overview of Phase I review, Phase II sampling and environmental assessment for redevelopment.
Open EPA guide NYSDECNew York guidance for site characterization, remedial investigation and remediation under DEC programs.
Open NYSDEC guidance NYSDOHNew York guidance and public-health information for soil vapor, sub-slab vapor and indoor-air evaluation.
Open NYSDOH resourceRegional Environmental Due Diligence
Angstrom supports environmental due-diligence projects throughout the New York metropolitan region and selected nearby areas, subject to scope, access, professional requirements and jurisdiction. View all Angstrom locations.
Supporting projects in Nassau County, Suffolk County, Queens and nearby Long Island communities.
View Rockville Centre locationSupporting Manhattan and environmental due-diligence projects throughout the five boroughs.
View Manhattan locationSupporting White Plains, Westchester County and selected nearby regional projects.
View White Plains locationPhase II Environmental Site Assessment Questions
A Phase II ESA is a site-specific investigation that generally uses physical sampling and laboratory analysis to evaluate selected environmental concerns at a property.
It is commonly performed after a Phase I ESA identifies a recognized environmental condition, suspected release, underground tank, vapor concern or former operation requiring site-specific testing.
Samples may include soil, groundwater, soil vapor, sub-slab vapor, indoor air, outdoor air or other media depending on the environmental concern and project objective.
No. Some investigations require soil borings or temporary groundwater points, while others may involve vapor, indoor air, surface soil or other targeted methods.
Yes. When vapor-forming chemicals are part of the concern, the scope may include soil vapor, sub-slab vapor, indoor air and outdoor comparison samples.
Not necessarily. A focused Phase II may answer selected due-diligence questions. Full horizontal and vertical delineation generally requires a scope developed specifically for that purpose.
The findings may support additional investigation, delineation, agency consultation, mitigation, remediation planning or other follow-up depending on the results and project context.
No. Angstrom provides independent environmental sampling, laboratory coordination, consulting and reporting. We do not perform excavation, tank removal, remediation or cleanup contracting.
Request a Phase II Environmental Site Assessment
Provide the property location, Phase I findings, former uses, recognized environmental conditions, suspected tanks, vapor concerns, available reports and transaction or project deadline.
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