England 0 CERCLA Remedial Investigation and Response Actions at Former England Air Force Base, Louisiana

24 Aug 2023: The purpose of this amendment is to update the Synopsis, post Government responses to contractor questions and extend the SF 330 submission date to 05 September 2023. 09 Aug 2023 - Attached to this amendment are draft government responses and draft Synopsis. The SF330 submission date is extended to 25 August 2023. Final documents will be posted soon (Minimal if any charges are expected).The Contractor shall provide A-E Services for the AFCEC environmental projects and are expected to complete activities such as:? Develop a preliminary geological and hydrological Conceptual Site Model (CSM), from available data at the installation from previous investigations and remedial actions and identify potential sampling points including groundwater monitoring well locations, to define the groundwater migration and geologic preferential pathways for contaminant migration. Consider sequence stratigraphy and lithological data available from historical reports to define a preliminary

geological model.? Aid in the placement of new groundwater monitoring wells supporting the RI, conduct preliminary sampling of surface water, groundwater, and sediment to establish a baseline of PFAS.? Develop and update of plans documenting the methods and procedures that will be used to conduct the RI including defining the nature and extent of PFAS contamination.? Collect and analyze geologic, geophysical, hydrogeological, ecological, chemical, physical and hydrologic data.? Collect and analyze environmental samples such as groundwater, soil, surface water, sediment, tissue, and drinking water.? Manage and dispose of investigation derived waste (IDW) and other waste generated during the execution of the activities.? Refine the Conceptual Site Exposure Model (CSEM) using validated environmental data to identify migration and sample pathways by which populations may be exposed to contaminants.? Perform a source strength assessment of PFAS impacted vadose zone sources.? Conduct Baseline Risk Assessments (BRAs) to evaluate the risk to human health and the environment in accordance with Louisiana?s Risk Evaluation/Corrective Action Program (RECAP) requirements (LDEQ, 2003).? Conduct Response Actions to respond to imminent threats to human health and the environment such as providing alternate water including bottled water and treatment systems.? Evaluate preliminary remedial alternative options to support RI scoping and response actions.? Design and implement interim remedial actions to manage migration or stabilize the site.? Prepare CERCLA documents such as RI, time critical removal actions, non-time critical removal actions, and other decision documents such as an Explanation of Significant Differences, interim proposed plans and interim ROD.? Support meetings such as public, stakeholder, and regulatory interface.? Update the CERCLA administrative record (AR) with applicable work products and reports.? Prepare and present expert testimony. All Questions are due 21 July 2023 at 5:00pm CST. This posting is related to the one posted on 11 May 2023.