Site Investigation and Remediation

Since the passage of the Resource Conservation and Recovery Act (RCRA) in 1976, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in 1980, and more recent State Hazardous Site programs, there has been an increasing need to conduct site investigations for hazardous site remediation. ECA engineers and geologists have extensive experience completing these types of projects.

CERCLA, RCRA AND STATE HAZARDOUS SITE INVESTIGATIONS

These investigations begin with identification of a site where a release has occurred. After a release is identified, environmental sampling and analysis is performed. If a release exceeding regulatory levels has occurred, notification of state and/or federal agencies is often required and, as a result, a site may be listed on a state or federal priority list. Listing is typically based on risk-based evaluation and scoring of a site.

In some cases, immediate source removal and other actions, such as receptor pathway elimination can result in elimination of the requirement to notify of a release or can result in a site not being listed for remedial action. ECA has been successful in using quick and innovative responses to avoid notification and to prevent listing of sites.

Accurate regulatory evaluation and scoring of a site may require additional assessment to determine the extent of releases and to collect receptor data (i.e., well locations, proximity of sensitive environmental areas, etc.). During initial assessment and any additional assessment, ECA anticipates feasible remedial alternatives so that assessment wells can later be converted into sparge or recovery wells. This approach can produce significant cost savings on sites that ultimately require remediation.

RISK ASSESSMENTS/SITE SCORING

Risk assessments and site scorings are performed to evaluate the risks to human health and ecological receptors associated with releases of hazardous substances. Federal and state regulations increasingly require that a risk-based approach be used for determining remediation goals and allowable discharge concentrations. These regulations include RCRA, CERCLA, CAA, CWA, and some state equivalents. With this development has come the opportunity for ECA to propose less stringent remediation and discharge standards for clients and to support such positions with site-specific risk-based analyses.

ECA risk assessment specialists bring expertise to each project in the fields of toxicology, statistics, environmental health, engineering, geology, groundwater hydrology, and surface-water hydrology.

The firm's scientists and engineers are trained to evaluate assessment alternatives to find cost-effective and feasible assessment solutions for meeting the environmental objectives of clients. Site-specific assessment data can support credible and defensible remediation goals that are less stringent than conservatively established default values designed to limit risks over a broad range of geological settings.

ECA performs all risk assessments in accordance with the most recent technical guidance and statistical methodologies approved by the USEPA or applicable states. ECA has up-to-date in-house information and uses only the most recent toxicological data available.

REMEDIAL SYSTEMS ENGINEERING AND DESIGN

ECA has considerable experience in applying a wide variety of remediation technologies to CERCLA, RCRA, and State Hazardous Waste Sites, as well as industrial, commercial, retail, and wholesale petroleum sites. ECA not only knows how to apply the latest remediation technologies but, also when, where, and how the technologies apply to particular environmental challenges. ECA's experience in this field ranges from simple excavation and disposal of soil to complex, multi-component remediation including soil vapor extraction (SVE), dual phase vapor extraction (DPVE), air sparging, in-situ and above ground bioremediation of soil and groundwater, air stripping, and effluent water treatment.

ECA typically combines the talents of geologists, senior technicians, and civil, geotechnical, and environmental engineers to design, install, and operate remediation systems.

ECA believes that the key to minimizing remediation costs is to rapidly develop and implement a turnkey source removal. Source removal and/or control prevents further impairment of the site. This approach satisfies the regulatory intent to cleanup sites as quickly as practicable and minimizes unnecessary remediation costs.

ECA begins the remediation process by developing a remedial action plan or corrective action plan. These plans may follow prescribed guidelines (e.g. CERCLA feasibility study, RCRA corrective measures study, etc.) or may be more generic. The plans outline how required cleanup levels can cost-effectively be achieved and may include preliminary design, construction, and operational details. ECA has successfully implemented remedial action plans for subsurface barriers, groundwater recovery wells, large diameter sumps with and without groundwater injection, and interceptor trenches.

During implementation of remedial actions, ECA provides on-site technical direction, inspection, and coordination of site remediation activities. These activities include complete installation and management of soil and groundwater remediation systems. Experienced, professional remediation personnel make critical decisions as the job progresses to control costs, maximize system efficiency, expedite schedules, maintain compliance with safety and hazardous substance handling protocols, and deal cost-effectively with changing site conditions.

Throughout the entire remediation process, ECA works closely with regulatory agencies to manage the implementation of the corrective measures. After developing scientific facts about the source, ECA develops an integrated remediation system that complies with site-specific negotiated cleanup levels. In-situ remediation systems such as bioremediation, air sparging, SVE, and DPVE are used to prevent long term risk associated with off-site disposal. ECA also utilizes aboveground remediation, such as soil piles where nutrients and oxygen are added to enhance bioremediation. ECA actively seeks out new technologies necessary for complex projects.

Finally, depending on the type of release and the client budget, it is sometimes advantageous to perform off-site disposal in pre-approved TSD facilities. ECA oversees the proper handling, containment, temporary storage, labeling, manifesting, transporting, and disposing of hazardous wastes.