Since the passing of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) parties involved in real estate transactions have become extremely concerned with the liabilities inherent with contaminated properties. The reason for the concern is due to the punitive legislation and costly cleanup associated with these properties.

Asset transfers accompanied by a properly completed due diligence process provides all parties with an understanding of the liabilities involved with the transfer, and in the event of environmental contamination being discovered after the transaction, helps qualify the new owner for the innocent landowner defense.

This chapter presents the various assessment methods used by environmental professionals and attorneys to assess real property for environmental impairment. This material should be found useful for attorneys assisting clients in evaluating, limiting, and managing risk with real property assets.

• Levels of Assessment
• Due Diligence
• Transaction Screening Assessment
• Phase I Environmental Site Assessment
• Phase II Site Investigation
• Phase III Remedial Investigation/Remedial Action

1.2 Levels of Assessment

The parties involved in a transfer of property may conduct various levels of environmental assessments. These assessments are completed to protect themselves from acquiring contaminated property and or CERCLA liability . The levels of assessment are referred to throughout the industry as the following: Due Diligence, Environmental Transaction Screen, Phase I Environmental Site Assessment (Phase I ESA), Phase II Site Investigation (Phase II SI), Phase III Remedial Investigation/ Feasibility Study (Phase III RI/FS). The term “environmental assessment” is used to describe the overall process, which may include more than one of these phases.

A description of these phases are provided below:

1.2.1 Due Diligence

Due diligence is the most common level of assessment used to determine whether a commercial or industrial property is environmentally sound; and to inform parties involved in the transfer of the property of it’s environmental condition. Due diligence incorporates elements of the transaction screen, Phase I Assessment, Phase II Investigation and Phase III Remediation if the property is contaminated. The scope of work involved in the due diligence will vary with each property.

Due diligence is particularly important in that it may later be used to satisfy some of the conditions of the “innocent landowner defense”. Under this defense the assessment must include all appropriate inquiry into the previous ownership and uses of the property consistent with good commercial or customary practice. However, there are no regulatory guidelines that define “ all appropriate inquiry” or “ good commercial or customary practice”.

1.2.2 Transaction Screen Assessment (TSA)

A Transaction Screen Assessment (TSA) is the least involved of the assessments and is performed to determine if a full Phase I ESA is necessary. The TSA may also be called a preliminary evaluation, initial assessment or property screening. The TSA is a scaled down version of the Phase I ESA. Buyers will typically perform this level of assessment themselves and determine if they need to go to a full Phase I ESA and retain outside consultation. This TSA will not satisfy due diligence and will not qualify a party for the innocent landowner defense. The TSA is typically not completed on commercial or industrial properties and is reserved for agricultural or residential properties with no history of commercial or industrial use.

1.2.3 Phase I Environmental Site Assessment (Phase I ESA)

Phase I ESA process is used to establish if a property may have been impacted and suffered environmental degradation from past uses, and/or from adjacent properties. This process is usually not intrusive and uses investigative techniques to discover what contaminants may be present on site. Site inspection, interviews, historical maps, aerial photos, city directories and sources of information can be used to conduct this level of investigation. A Phase I ESA may also be called a due diligence evaluation, transfer assessment or site evaluation.

1.2.4 Phase II Site Investigation (Phase II SI)

A Phase II SI is an intrusive investigation involving the collection of air, soil and water samples to confirm if the property has been impacted by contaminants causing environmental degradation. This phase may also be referred to as subsurface investigation, test pit investigation, or baseline environmental assessment.

1.2.5 Phase III Remedial Investigation/ Feasibility Study (Phase III RI/FS)

A Phase III RI/FS may be completed to fully define or characterize the extent of soil and water impact identified in the Phase II SI. During this phase remediation alternatives can be developed with cost estimates and feasibility studies. This Phase may also be called remedial action investigation, site characterization, or remedial investigation.

1.3 Summary

Each environmental assessment will progress based on the site and findings in each phase of the assessment. If the Phase I ESA discovers no potential impacts from prior uses then assessment process may stop there. If the Phase I ESA process concludes the property may have been impacted from past use then a Phase II SI would be performed to confirm the findings in the Phase I ESA. If the Phase II SI discovers contamination then a Phase III RI/FS may be completed to define the extents of the contamination, remediation alternatives, feasibility studies and cost estimates.

2.0 Due Diligence

Due Diligence is a study of the property and it’s history to determine the likelihood of environmental degradation of the property. Information obtained through the study can help parties decide whether to complete the property transaction, what the property is worth, and which party shall bear the liability for remediation, if necessary.

Properly completed due diligence can also qualify a purchaser for the innocent landowner defense, and control liability in the event of the future discovery of contamination on the property.

If due diligence is ever to be used to support the innocent landowner defense, it may include a Phase I ESA, Phase II SI, and a Phase III RI/FS.

The extent and scope of the due diligence process is based on the presence, or absence of contamination, the level of study required to determine the extent of contamination, and the willingness of the parties involved to continue their involvement.

Once a study is complete and the condition of the property is determined, the three following scenarios may apply:

Uncontaminated Property (“Clean”): The innocent landowner defense claims that a property owner performed all appropriate inquiry to determine whether the property had been contaminated; under this category the property was found not to be contaminated.

Contaminated Property (a): If a property is found to be contaminated, the parties may develop an agreement defining that the transfer shall be completed after the seller completes the remediation of the property. Even after acquisition of the property the purchaser may still claim the innocent landowner defense, based on the belief that the contamination was adequately remediated and that an uncontaminated “clean” property was purchased.

Contaminated Property (b): If a purchaser knowingly buys contaminated property without remediation, the purchaser then takes on the responsibility for the environmental condition of the property and financial liability for remediation. In this case the purchaser is not qualified for the innocent landowner defense.

Four key elements must be understood about due diligence and its impacts:

¨The ASTM Standard;
¨The scope of environmental assessments in due diligence;
¨Strict, joint, several, and retroactive liability;
¨CERCLA, implications for various parties

Only two of these elements will be discussed in the remainder of this course they are the ASTM Standard, and the scope of environmental assessments in due diligence. The last two elements are beyond the scope of this course.

2.1 ASTM Standard

Due diligence can assist parties in avoiding liability, if properly performed. No government regulations exists to define the requirements of the process so the American Society for Testing and Materials (ASTM) has developed a standard for due diligence. This standard includes three separate titles:

¨E1527-00 Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process.

¨E1528-00 Standard Practice for Environmental Site Assessments: Transaction Screen Process.

¨E1903-00 Standard Guide for Environmental Site Assessments: Phase II Environmental Site Assessment Process.

The ASTM standard is accepted by the industry as the minimum requirements for performing due diligence. The remainder of this course shall present the requirements included in these standards for performing a TSA, Phase I ESA, Phase II SI, and Phase III RI/FS.

3.0 Transaction Screening Assessment

The Transaction Screen Assessment (TSA) is a simplified version of the Phase I ESA and is usually prepared by buyers on their own to determine if a full Phase I ESA and outside consultation is required.

This assessment is defined by the ASTM Standard E1528-00 and consists of a questionnaire that is filled out and is used to determine if any environmental may exist at the property. The use of this assessment is typically limited to low risk properties like agriculture and residential land with no prior industrial or commercial use. The use of this assessment alone would not qualify the buyer for the innocent landowner in the event of contamination being discovered on the property in the future.

The TSA is only a screening tool and should not be relied on solely to support an asset transfer of commercial or industrial property.

4.0 Phase I Environmental Site Assessment (Phase I ESA)

4.1 Purpose

The Phase I ESA is a study that reviews the current and past uses to determine the potential presence of contaminants. This study is typically the first in the due diligence process.

The findings of a Phase I ESA assists parties in determining the following:

¨ No contamination is likely and no further environmental evaluation is necessary, or;

¨Contamination and environmental degradation is likely and additional
investigation is necessary, such as a Phase II ESA.

This must include evaluation of past and present uses of target properties, adjacent properties and nearby properties within a specified distance. The study must include the following four major elements:

¨A records review;
¨A site reconnaissance;
¨Interviews with owners or occupants and government officials;
¨Preparation of the report and development of recommendations.

ASTM requirements for each of these elements is discussed detail in the following sections.

4.2 Records Review

This process involves obtaining records including a site description with location, legal descriptions, regulatory records for the site and surrounding properties, and historical uses of the site.

4.2.1 Ownership and Location of Site

Identify the current owner by name and address, and identify the tax map parcel number. Include tax maps, property surveys or available plans identifying property boundaries in the report.

4.2.2 Current Use of the Site

The study should include a discussion of the current uses of the site. Each use or site activity should be reviewed to determine if activity may have resulted in contamination of the site. (For example; chemicals were used on site and disposed of through the site sewer system. This sewer system is discovered to consist of an on-site leach field that disposes septic waste by way of a subsurface disposal system (leach field). This would be a suspect activity and could trigger a Phase II SI.

4.2.3 Regulatory Agency Information Sources

Federal, state and local information sources must be searched during the Phase I ESA process. The ASTM Standard lists the federal and state environmental sources that must be reviewed, as well as the search distances for each source. Below is a list of the federal, state and local databases with search distances included in the standard:

¨Federal National Priorities list (NPL) – 1-mile radius
¨Federal Comprehensive Environmental Response Compensation and Liability Information System (CERCLIS) list – 1-mile radius
¨Federal RCRA Transportation, Storage and Disposal (TSD) Facilities list – 1-mile radius
¨Federal Emergency Response Notification System (ERNS) list – 1-mile radius
¨State list of hazardous waste sites CERCLIS and NPL equivalents – 1mile radius
¨State Landfill or Solid Waste Disposal Site list- ½ mile radius
¨State Leaking Underground Storage Tanks (LUST) list –1/2-mile radius
¨ State registered Underground Storage Tank (UST) list- property and adjacent properties
¨Local records on landfills/solid waste disposal facilities, hazardous waste/ contaminated sites, registered underground tanks, record of emergency release reports (SARA 304), and records of contaminated public wells.

4.2.4 Historical Uses of the Site

A study of the past and current uses of the site is of key importance to determining if a site has a high potential for being contaminated. This part of the Phase I ESA process is one of the most important parts and is where an experienced environmental professional will be recognized. The ASTM Standard requires researching the history of a site back to the first developed use, or to 1940 whichever is earlier. In order to meet the ASTM requirements at least one of the following standard historical sources must be consulted. The ASTM Standard specifies reviewing only as many historical sources as are necessary, reasonable ascertainable, and likely to be useful.
¨ Arial Photographs
¨ USGS topographic maps
¨ Sanborn Fire Insurance Maps
¨ Historic Maps
¨ Historic Directories
¨ Planning Department Records
¨ Tax Assessor Maps
¨ Tax Assessor Records

4.3 Site Reconnaissance

The purpose of a site reconnaissance is to obtain information indicating the likelihood of environmental contamination being present, from current or past operations. The following areas should be reviewed and addressed during the reconnaissance of Phase I ESA.

4.3.1 Physical Setting of Site

The physical setting of the Site must be inspected and documented, including acreage of the property with identification of the legal property boundaries. This can be determined from the tax assessor’s records or by a Site Plan provided by the owner. The ASTM Standard requires, as a minimum, a USGS topographic map be reviewed as a source of information on the physical setting of the property.

The layout of buildings, foundations, abandoned structures, and surface improvements should be documented in a site plan. The percentage of the Site occupied by buildings and pavement should be estimated and documented by the consultant. The general condition of floors (stains, oil, bulk chemicals) inside the buildings and outdoor areas should be noted.

The geology, topography and hydraulic features (ponds, rivers) on site should be reviewed to estimate the direction of ground water flow and surface runoff patterns. This information is interpreted by the environmental professional to assess the extent to which off-site migration of contaminants may impact the Site.

Naturally-occurring surface waters including stream, ponds lakes, rivers or wetlands located on site may be significant because they are a potential waste discharge points and may provide a conduit for contaminant migration to or from the Site. These features should be reviewed and evaluated for contaminant migration.

4.3.2 Site Features

The following natural and man-made features should be reviewed to determine how they were used, and the potential for discharge of contaminants via these features to the soil and water of the Site.

Water Sources- The facility’s drinking water or process water source(s) should be identified, including information on abandoned or active wells on site.

Water and Waste Management – Water and waste management units such as septic systems, lagoons, pits, catch basins, drywells, floor drains, sumps or surface impoundments should be identified and evaluated to determine if contaminants have been released to the site via these features.

Underground Storage Tanks (USTs) and Aboveground Storage Tanks (ASTs) – All USTs and ASTs should be located and described, including gasoline tanks, heating oil tanks, waste oil tanks, emergency generators tanks, oil-water separators and other product tanks. Information on the tanks should include location, product stored, registration status, volume, contents stored over the life of the tank, the age, construction material, corrosion protection, inventory control, results of testing, and past malfunctions with the tank. In addition, these tanks should be inspected for signs of leaks or failures.

Evidence of removed or abandoned tanks should be searched for including patched pavement, vent pipes and fill ports.

Leaking USTs and ASTs may be significant source of contamination and this feature should be thoroughly assessed.

Electric Transformers – The presence of electric transformers and capacitors should be determined during the site inspection. These transformers should be inspected for leaks and determine if they contain Polychlorinated Phynols (PCBs).

Monitoring Wells – If present on site the purpose of the wells should be determined and all test data should be obtained and included in the report.

4.4 Interviews

4.4.1 Interviews with Key Site Personnel

Interviewing site personnel or individuals knowledgeable with the current and historic uses of the Site is of key importance. Interviews with key personnel must be attempted, and a record of interviews should be included in the report.

4.4.2 Interviewing Government Officials

Government officials should be reviewed to obtain information about the recognized environmental condition of the Site. Interviews can be conducted in person or by phone and a record of the interview should be included in the report.

4.5 Research Specifically for Stock Purchase Transactions

Research for stock purchase transactions will not be covered in this course.

4.6 Report

The purpose of the Phase I ESA report is to document the recognized environmental conditions discovered during the course of the assessment. The report must describe the methods, information sources used, and the standards to which the work was performed, present the findings, and support the conclusion and recommendations.

The following is a typical outline of a Phase I ESA Report:

I. Introduction
II. Site Location and Description
III. Description of Current and Prior Site Use
IV. Summary of Findings and Conclusions
V. Recommendations
VI. Limitations
Attachments
Site Location Map
Site Map
Aerial Photographs
Sanborn Fire Insurance Maps
Chain-of-Title Documentation
Photographs

4.6.1 Summary of Findings and Conclusions

The environmental professional provides an opinion on the probability of the Site being impacted with environmental contaminants from past or current use. When developing these opinions the consultant should consider the following aspects of the assessment:

¨ The nature of evidence and whether it is conclusive;
¨The quality of information collected, including whether the information is corroborated by other sources;
¨ The potential environmental liabilities resulting from the environmental conditions;
¨ The possible actions the lead regulatory agency will take regarding each environmental condition.

The ASTM standard recommends that reports include in the findings and conclusion section, a statement that the ESA has been performed in accordance with the standard, the address of the Site, and any exceptions to or exclusions from the standard.

4.6.2 Recommendations

Phase I ESA Reports may conclude with a discussion of recommendations. These recommendations typically provide a rationale for additional investigation, if recommended.

4.6.3 Limitations

Limitations should be included to remind parties of the limits of the study. Typical limitations are exclusion of asbestos and lead, and use of the report by third parties. The report should also identify the party who is intended to rely on the report. Attorneys may wish to label the reports attorney-client privilege to avoid having to produce the document in the event of a subpoena.

5.0 Phase II Site Investigation (Phase II SI) Process

5.1 Purpose

The Phase II Site Investigation (SI) is defined as an intrusive study of the Site’s soil, sludge, water, groundwater, and waste material to evaluate both the location and the extent of impacts from historical uses. SI’s are performed to verify the presence of environmental contaminants alleged to be on site, as determined by the Phase I ESA.

According to the ASTM Standard (E1903-00) the SI has four main components:

¨The development of the scope of work;
¨The investigation methods and activities;
¨The evaluation and presentation of the data;
¨The preparation of the findings and conclusions.

ASTM requirements for each of these elements is discussed detail in the following sections.

5.2 Defining Objective and Scope of Work

A scope of work should be defined that states what the areas of concern are, how they will be investigated, and what they will be investigated for. All parties should agree on this scope and objective prior to performing the investigation.

5.3 Identifying the Potential Contaminants

A list of the contaminants believed to be on site should be developed. This list is based the contaminants and chemicals used on site and should be identified in the Phase I ESA

5.4 Migration Pathways

Once a list of potential contaminants has been developed and areas of concern have been defined, migration pathways can be predicted. A migration pathway is a route a contaminant may have traveled and entered into the soil and groundwater of the Site, or how it has been dispersed throughout the Site. For example a historical disposal of contaminants into an on-site septic system will allow the contaminants to migrate from the septic system, via the leach field piping, into the soil and leach into the groundwater. The contaminants could then migrate in the groundwater towards a domestic well.

5.5 Sampling Strategy

The sampling strategy is developed to achieve the objective of the SI. The types of samples to be collected, laboratory analysis, areas of sampling, the depth and number of samples to be collected are determined. The sampling strategy should effectively evaluate the areas of concern to determine what environmental contaminants are present, what concentrations they are at, and define the source of the contaminants.

5.6 Investigation Methods and Activities

The methods of the investigation to be used are based on the required sampling strategy, geology of the Site, and the requirements of the sampling (depth, surface cover, location of suspect contaminants, etc.).

Some methods of investigations include collection of soil samples by hand augering, direct push sampling, rotary drill technology and excavation.

5.7 Site Investigation Work Plan

Before any work is completed an investigation work plan should be developed by the consultant. The objective of the work plan is to attain a consensus from all parties involved on the work to be performed. Note, the scope of work included in a proposal may be sufficient to satisfy the requirements of a work plan. The purpose of the work plan according to the ASTM Standard is to:

¨Explain what and where the environmental conditions are
¨Outline the objectives of the SI.
¨Explain the reasoning in the development of the sampling strategy and the analytical program.
¨Specify the sampling strategy, technologies, and analytical methods to be used.
¨Present QA/QC programs
¨Provide all pertinent details and information concerning implementation of the SI.
¨Detail the deliverables
¨Provide locations of sampling
¨Specify equipment decontamination
¨Analytical methods for each sample
¨List health and Safety requirements

5.8 Health and Safety Plan

A Site Health and Safety Plan (HASP) are prepared to protect the health of the on-site employees and provide protection to the surrounding community from the hazards of the SI. The HASP should be prepared by a health and safety professional.

5.9 Interpreting Sampling Data

If the SI discovers contaminants on site then consultant can typically determine if the contaminants present a problem by comparing the concentrations of contaminants to federal and state Standards, Criteria, or Guidelines (SCGs).

If contaminants detected on site are not listed in the SCGs than a risk assessment may need to be performed by the consultant to assess the significance of the findings.

5.9.1 Standards, Criteria, and Guidelines

Standards, Criteria, and Guidelines (SCGs) are the published allowable levels of contaminants in a particular medium (soil, water) and are set by the federal or state authorities. Standards are legally enforceable regulatory levels that must be complied with under specified conditions. Criteria or guidelines are not typically enforceable by law.

5.10 Site Investigation Report

The SI report should fully describe the work performed, document the information gathered, and provide an evaluation of the data. According to the ASTM Standard, in preparing the report the consultant must review all data collected, correlate it to the list of recognized environmental conditions, and determine if any contamination actually exists. If any investigation work was completed different than outlined in the work plan then the changes and reasons for the changes need to be discussed. The ASTM Standard suggests the SI report follow the following format:

I. Introduction
II. Background Information
III. Phase II SI Activities
IV. Evaluation and Presentaion of Results
V. Discussion of Findings and Conclusions
VI. Recommendations

Attachments: Tables, figures, photographs, boring logs, laboratory results, chain of custody forms.

Upon conclusion of the SI, the environmental conditions of the property will have been assessed and a determination made as to whether any contamination is present. If no contamination is discovered and reasonable inquiry has been made, then the consultant may recommend no further environmental evaluation for the Site. If contamination is discovered, then the parties may withdraw from the transaction, or negotiate the cost of remediation for the Site. If remediation cost estimates are needed, then additional investigation may be necessary to define the extent of the contamination and gather information for remediation alternatives and development of remediation cost.

6.0 Phase III Remedial Investigation/Remedial Action (Phase III RI/RA) Process

6.1 Purpose

A Phase III is a combination of investigations and remediation efforts performed to fully characterize and remediate environmental contamination and liabilities previously discovered on site during the Phase-II SI process.

The objectives of the Phase III process include:

¨ Characterize the vertical and horizontal extent of soil and groundwater contamination;
¨ Assess health risks;
¨ Identify and review potential remedial action alternatives;
¨ Determine the feasibility of implementing these alternatives;
¨ Select and implement the most appropriate cleanup strategies

The standards for the Phase III process have been established by the CERCLA, and the National Oil and Hazard Substance Contingency Plan (NCP). The process has been developed for superfund sites and is designed to identify, evaluate, and select cost effective remedial action alternatives that adequately protect human health and the environment. Not all components of this process apply to all sites, but the general framework this evaluation process can be applied to each site to evaluate potential impact to public health, to assist in identifying applicable remedial action alternatives and in setting appropriate cleanup levels. The following sections provide and overview of the process.

6.2 Site Characterization

The objective of a site characterization is to fully define the horizontal and vertical extents of the soil and groundwater contamination, and gather on the physical properties of the site, including soil characteristics, groundwater conditions and surface water influences. This data is then used to develop remediation alternatives.

A work plan should be developed to characterize the site. The work plan can be agreed upon by all parties and include all quality control programs and specific standards to be used for characterization. The work plan should also provide details on collection, analysis, and review of soil, water and air.

6.3 Exposure Assessment and Selection of Remedial Action

Remediation of sites are typically designed to reducing the human exposure of contaminants to within an acceptable risk levels. The exposure evaluation is based on a contaminant being present at a certain level on site and migrating to a population where exposure to this population may occur. The remediation is then developed to reduce or control the exposures to allowable levels. Once a remedial action is complete, post remediation sampling and monitoring will continue to ensure the remediation was successful.

6.3.1 Public Health Evaluation Process

The health evaluation process begins with the identification of indicator chemicals (chemicals identified to be of greatest concern) at the site where a known release has occurred. Potential exposure pathways for these chemicals are identified by determining release sources and release media. Potential human exposure points are identified and characterized. Release sources are reevaluated within the context of potential human exposures to identify environmental transport methods and pathways (exposure routes and pathways). An evaluation of sensitive receptors (human populations) is also included in this phase of the exposure assessment.

Chemical releases are then quantified to estimate exposure point concentrations and to predict how these chemicals will react in, move through the environment, and expose human populations. Estimated exposure concentrations are calculated and compared to existing requirements and standards.

6.3.2 Indicator Chemicals

Indicator chemicals are chemicals identified on site to present the highest public health risk. These chemicals are considered the greatest public health risk because they represent the most toxic, mobile, and persistent and are those known to be present in the greatest amounts. A list of these indicator chemicals are developed per site and used in the public health assessment process.

6.3.3 Fate/Transport Evaluation

Receptors such as residential neighborhoods, onsite workers, and employees are first identified. The potential pathways for these populations to be exposed are determined, including ingestion of soil, inhalation of dust particulates, dermal (skin) contact, etc. The evaluation estimates the baseline environmental concentrations of indicator chemicals so that the duration of human exposure in the absence of remedial action can be determined. The evaluation estimates how and when exposures to human health will occur from the known hazardous waste on site.

6.3.4 Toxicology Assessment

Human intake of indicator chemicals are calculated from exposure point concentrations. The intake amounts at exposure points can be estimated or determined by actual sampling at the exposure point. The intake amounts are then used with toxicity data to perform a toxicology assessment. Toxicology assessments determine the increased health related risks associated with the exposure.

6.3.5 Remedial Action Alternatives Analysis

The analysis of each remediation alternative is an evaluation of how effective each alternative is on controlling the source of contamination, how migration is to be prevented, and how effective the alternative is in reducing exposures.

6.3.6 Remedial Action

Remediation selected for a site may be as simple as capping the contaminated soil on the site with a clean layer of soil and developing a vegetative growth (grass) cover. Other remediation alternatives may consist of a complete removal of the source contamination with a groundwater and vapor recovery system.

6.3.7 Closure, Post-Closure, and Certifications

Depending of the selected remediation method, closure and post closure sampling may be needed. For example, if remediation consists of capping a site with clean soil then no closure or post closure sample may need to be completed. Once the remediation is completed, the leading government agency directing the remediation would issue a certification letter, or a no-further-action letter indicating the remediation was complete.

If the remediation consisted of an ongoing groundwater and vapor recovery system then sampling may be required to demonstrate the groundwater had been cleaned to standards, and sampling may need to continue after closure to ensure contamination does not recur.

Each remediation strategy will be structured specifically for each site with closure sampling and monitoring requirements determined by the lead agency.