Environmental Due Diligence and Site-Specific Sampling
Site-specific environmental investigation involving soil, groundwater, soil vapor, sub-slab vapor, indoor air, underground storage tank concerns, laboratory analysis, data interpretation and written reporting.
Site-specific environmental investigation
A Phase II Environmental Site Assessment is an investigation used to evaluate whether contamination is present in selected areas of concern at a property. Unlike a Phase I ESA, which primarily involves records review, historical research, interviews and a site inspection, a Phase II ESA generally includes physical sampling and laboratory analysis.
A Phase II ESA is commonly requested after a Phase I assessment identifies a recognized environmental condition, suspected release, underground storage tank concern, dry-cleaning operation, gas station, auto-repair use, industrial activity, chemical-storage area, vapor-intrusion concern or another condition requiring site-specific data.
Depending on the property and objective, the investigation may include soil, groundwater, soil vapor, sub-slab vapor, indoor air, surface water, sediment or other environmental media.
Environmental due diligence stages
The two assessments serve related but different purposes. The Phase I identifies potential environmental concerns; the Phase II collects physical data about 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 recognized environmental conditions
Sampling locations and analytical parameters should be based on the Phase I findings, site history, suspected source, property layout, transaction objective and applicable jurisdiction.
Historic fuel dispensing, underground tanks, fill ports, piping and petroleum handling may warrant soil, groundwater or vapor sampling.
Chlorinated solvents and other volatile chemicals may create soil, groundwater and vapor-intrusion concerns.
Petroleum products, waste oil, solvents, floor drains, hydraulic equipment and former tanks may require investigation.
Known or suspected tanks, fill pipes, vent pipes, petroleum odors, stained soil or incomplete closure records may warrant testing.
Historic processes, chemical storage, waste handling, machine shops and loading areas may create several potential source areas.
Volatile chemicals in soil or groundwater may migrate toward an occupied building through cracks and utility pathways.
Redevelopment planning may require environmental data about contaminants, source areas and affected media.
Buyers, sellers, lenders, attorneys and investors may request sampling before acquisition, refinancing or development.
Environmental media and investigation support
The scope may include one environmental medium or several complementary sampling methods depending on the recognized environmental condition and project objective.
Soil samples may be collected near tanks, former operations, stained soil, fill areas, drains, chemical-storage locations or other suspected source areas.
Groundwater may be evaluated where subsurface contamination, petroleum impacts, solvent migration or monitoring-well data are relevant.
Soil vapor samples may help evaluate VOCs and other vapor-forming contaminants in the subsurface near or beneath a property.
Samples may be collected beneath a building slab when the potential for contaminant-vapor migration into the building is being evaluated.
Indoor and outdoor air samples may be included in a vapor-intrusion evaluation together with a survey of potential indoor chemical sources.
View indoor air testingTesting may address tank locations, suspected releases, petroleum impacts, closure observations or property-transaction concerns.
View UST assessment servicesGround-penetrating radar, electromagnetic methods or magnetometry may help evaluate suspected tanks, buried objects and subsurface features.
Selected projects may require samples from drainage features, ponds, streams, outfalls, sediment or other environmental media.
Sample containers, preservation, holding times, quality-control samples and laboratory methods are selected for the media and analytes.
Documentation may include sample identifiers, depths, media, photographs, field notes, figures or site plans when included in the scope.
Results are reviewed with site history, sample location, depth, reporting limits and selected due-diligence or regulatory criteria.
Reports may present the scope, methods, results, figures, interpretation, assumptions, limitations and recommended next steps.
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, degreasers, 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 may be associated with combustion, fill, petroleum, manufactured gas and certain historic industrial uses.
Lead, arsenic, mercury, chromium, cadmium, nickel and other metals may be selected based on site operations and historic fill.
PCB analysis may be appropriate for certain electrical, manufacturing, hydraulic-fluid or historic industrial concerns.
Agricultural, landscaping, pest-control, storage or manufacturing history may warrant selected pesticide or herbicide 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. Sampling locations are normally selected from Phase I findings, historic site uses, visible conditions and the conceptual understanding of potential contaminant migration.
Investigation areas may include tanks, former dispensers, fill pipes, floor drains, loading areas, chemical-storage areas, stained soil, dry-cleaning equipment, waste handling locations and former manufacturing operations.
Soil vapor, sub-slab vapor and indoor air
Vapor intrusion may occur when volatile chemicals migrate from contaminated soil or groundwater toward an overlying building and enter through cracks, utility penetrations, sumps, floor drains, crawl spaces, basements or other pathways.
A vapor-intrusion investigation may include soil vapor, sub-slab vapor, indoor air and outdoor air samples. Building surveys and an inventory of indoor products and chemical sources are important because indoor activities can affect air-sample results.
Heating oil, gasoline and petroleum releases
Underground tanks and associated piping can create environmental concerns during property transactions, tank closure, redevelopment or suspected-release investigations.
A Phase II scope may include review of the known or suspected tank location, geophysical findings, soil observations, soil samples, groundwater samples, vapor samples and petroleum-related laboratory analysis.
View Underground Storage Tank ServicesDefine the purpose before fieldwork begins
The project purpose affects the number of samples, locations, methods, screening criteria, documentation and level of investigation.
Focused sampling may be designed to answer specific buyer, seller, lender or attorney questions before a transaction.
Sampling may evaluate whether selected contaminants are present in suspected source areas and environmental media.
Additional sampling may be required to define the horizontal and vertical extent of confirmed environmental impacts.
Agency-directed work may require jurisdiction-specific work plans, methods, reporting, notifications and licensed professionals.
From recognized condition to written findings
We review the recognized environmental conditions, site history, records, maps, prior reports and project objective.
Areas, media, depths, analytes, methods and quality-control needs are selected for the environmental question.
Access, utilities, subcontractors, drilling, geophysical work, building conditions and site-safety needs are addressed.
Soil, groundwater, vapor, indoor air or other samples are collected according to the agreed project scope.
Samples are submitted using suitable containers, preservation, chain-of-custody and media-specific analytical methods.
Results are reviewed with sample locations, depths, site history, QA/QC information and selected screening criteria.
The report documents the scope, methods, findings, assumptions, limitations and recommended next steps.
Environmental due-diligence documentation
The final format depends on the transaction, investigation objective, number of samples, regulatory context and agreed scope.
View Licensing and CertificationsUnderstanding the investigation boundaries
Findings apply to the locations, depths, media and conditions included in the sampling plan.
A non-detect at one location does not prove that contamination is absent from all portions of a property.
Groundwater, vapor, building pressure and environmental conditions can vary seasonally and over time.
A focused due-diligence scope may not define the complete horizontal or vertical extent of environmental impacts.
Real estate, redevelopment and property management
Related property and environmental services
Property and environmental guidance
Basements, floor cracks, sumps, utility penetrations and below-grade spaces can affect contaminant and odor pathways.
Read article Indoor Chemical SourcesIndoor materials and products should be considered when interpreting indoor air results during chemical-vapor investigations.
Read article Building HazardsBuilding-material hazards may require separate evaluation during redevelopment, renovation or real estate due diligence.
Read article Resource LibraryBrowse Angstrom articles about environmental testing, building conditions, contamination, indoor air and property documentation.
Browse all articlesOfficial standards and agency resources
Review current technical standards and federal, New York and New Jersey resources related to environmental site investigation, laboratory analysis, vapor intrusion and contaminated properties.
Standard practice addressing the objectives, scope, scientific approach and reporting of Phase II environmental site assessments.
Open ASTM resource EPAEPA information about Phase I review, Phase II sampling and environmental assessment of properties considered for redevelopment.
Open EPA guide EPAFederal information about subsurface vapor sources, migration pathways, indoor air and vapor-intrusion assessment.
Open EPA resource NYSDECNew York guidance for site characterization, remedial investigation and remediation under DEC remedial programs.
Open NYSDEC guidance NYSDOHNew York State public-health information about soil vapor, sub-slab vapor, indoor air and exposure-pathway evaluation.
Open NYSDOH resource NYSDOHSearch New York environmental laboratories by matrix, analyte, analytical method and approved accreditation field.
Search laboratories NJDEPNew Jersey technical guidance for contaminated-site investigation, remediation and redevelopment.
Open NJDEP guidance NYSDECNew York information concerning releases from regulated underground storage tank systems.
Open NYSDEC resourceRegional environmental due diligence
Angstrom provides Phase II assessment support throughout the New York metropolitan region and nearby areas of New Jersey and Connecticut, subject to project scope, access and jurisdictional requirements.
Supporting environmental due-diligence projects in Nassau County, Suffolk County, Queens and nearby Long Island communities.
View Rockville Centre locationSupporting Manhattan, Brooklyn, Queens, the Bronx, Staten Island and New York City property transactions.
View Manhattan locationSupporting Westchester County and selected environmental projects in nearby areas of southern Connecticut.
View White Plains locationPhase II environmental site assessment questions
A Phase II ESA is a site-specific environmental investigation that generally includes physical sampling and laboratory analysis to evaluate whether contamination is present in selected areas of concern.
It is commonly performed when a Phase I ESA identifies a recognized environmental condition, suspected release, underground tank, vapor-intrusion concern or former operation that requires site-specific testing.
Samples may include soil, groundwater, soil vapor, sub-slab vapor, indoor air, outdoor air, surface water, sediment or other media depending on the site history and project objective.
No. Some projects require soil borings or monitoring wells, while others may involve vapor, indoor air, surface soil or other targeted sampling. The field method depends on the concern and required sample depth.
Yes. Testing may include soil vapor, sub-slab vapor, indoor air and outdoor comparison samples when vapor-forming chemicals are part of the recognized environmental condition.
A suspected tank may require records review, visual inspection and geophysical screening. Soil or groundwater sampling may then be used to evaluate whether a suspected tank affected the environment.
Not necessarily. A limited Phase II ESA may answer specific transaction questions. Full horizontal and vertical delineation normally requires a sampling plan developed specifically for that purpose.
The findings may support additional sampling, contaminant delineation, agency consultation, vapor mitigation, tank work, remediation planning or other follow-up actions 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.
Helpful information includes the property address, Phase I ESA, recognized environmental conditions, site plan, transaction deadline, suspected tanks, former operations, available reports, requested media and lender or attorney requirements.
Angstrom provides Phase II assessment support in New York City, Long Island, Westchester, southern Connecticut, eastern New Jersey and nearby areas.
Request a Phase II environmental assessment
Provide the property location, Phase I findings, former property uses, suspected source areas, tank concerns, vapor concerns, transaction deadline and environmental media that may require testing.
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Angstrom Testing Services LLC provides independent environmental consulting, industrial hygiene assessments, indoor air quality diagnostics, and environmental sampling throughout New York City, Long Island, Westchester, and surrounding areas.
Services include mold testing and air sampling, asbestos inspections, indoor air quality testing, lead inspections, and water quality testing. Angstrom provides testing and consulting services only and is not financially affiliated with remediation or abatement contractors.