Five Year Review Include the Following
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THIRD FIVE-YEAR REVIEW REPORT FOR THE DUTCHTOWN TREATMENT PLANT SUPERFUND SITE DUTCHTOWN, ASCENSION PARISH, LOUISIANA AUGUST 17, 2011 PREPARED BY: United States Environmental Protection Agency Region 6 Dallas, Texas THIRD FIVE-YEAR REVIEW REPORT Dutchtown Treatment Plant Superfund Site EPA ID No. LAD980879449 Dutchtown, Ascension Parish, Louisiana This memorandum documents the United States Environmental Protection Agency’s (EPA’s) performance, determinations, and approval of the Dutchtown Treatment Plant Superfund Site (Dutchtown Site) third five-year review under Section 121(c) of the Comprehensive Environmental Response, Compensation, and Liability Act, 42 United States Code Section 9621(c), as provided in the attached Third Five-Year Review Report prepared by EA Engineering, Science, and Technology, Inc. (EA) on behalf of EPA. Summary of Third Five-Year Review Findings The third five-year review for the Dutchtown Site was performed through a review of site documents and site-specific requirements; a site inspection performed on June 1, 2011; interviews with personnel from the Louisiana Department of Environmental Quality (LDEQ) and ARCADIS Geraghty & Miller, Inc., the contractor to the Dutchtown Oil Treatment Site Participating Group (also known as the Dutchtown Steering Committee); and a review of data collected for the site during the third five-year review period. The site remedy included monitored natural attenuation of groundwater; maintaining the existing clay cap and fence; closing out the well on the former Watts (now Gaudet) property and drilling a replacement well; applying physical on-site controls such as access restrictions and installation of signs; implementing institutional controls (ICs) in the form of restrictions on future use of property, conveyance notifications, and/or restriction on use of groundwater from the site water wells. The remedial action (RA) was initiated in July 1997 with site mobilization; construction completion was attained in January 1998. Operation and maintenance (O&M) activities were scheduled quarterly for the first year after the RA, then semiannually from years 2 through 5. Starting in year 6, O&M activities were scheduled annually. The previous Five-Year Review Report (EPA 2007) stated that monitoring wells MW-10, MW-14, and MW-20 were lost, and they remain lost at the time of the current review. To date, the french drain located on the western edge of the site has not been formally investigated for the site-specific contaminants of concern (COCs). Monitoring wells MW-16 and MW-17 were plugged and abandoned in December 2003. The removal of these wells prevents monitoring of the groundwater south of the cap. Monitoring well MW-12 was plugged and abandoned in 2007. The third five-year review found that the selected remedy is performing as intended, and is protective of human health and the environment. The remedy will be protective in the long term provided the land use remains unchanged and site maintenance continues. Actions Recommended The O&M Plan should be updated to reflect the current monitoring network as well as provide an analysis of whether the lost monitoring wells (i.e., MW-10, MW-14, and MW-20) could provide a conduit for contamination to lower ground water intervals. A plugging and abandonment report should be provided for MW-12. The branches that have fallen on the fence should be removed and minor damage to the fence should be repaired. Should site land use change in the future, then it may be necessary to sample the french drain for the Dutchtown Site COCs. Based on the analytical results, future actions can be determined concerning the final disposition of the french drain. If development is proposed in the future, it may also be necessary to add one or more monitoring wells along the south side of the cap. Additional 1 rcs and/or access controls should also be considered at that time, to ensure that the selected remedy remains protective of human health and the environment. Site inspections should continue to be performed at least once per year to check the condition ofthe cap and site access restrictions (fencing and warning signs), and miscellaneous repairs and mowing should be performed as necessary to maintain current conditions. Determinations r have determined that the remedy for the Dutchtown Treatment Plant Superfund Site is protective of human health and the environment and that current human exposure is controlled. Thus the remedy is protective, and it will remain so provided the action items herein are addressed and corrective actions implemented. Samuel Coleman, P.E. Date I 1 Director Superfund Division, Region 6 U.S. Environmental Protection Agency 2 CONCURRENCES: THIRD FIVE-YEAR REVIEW REPORT DUTCHTOWN TREATMENT PLANT SUPERFUND SITE EPA ID No. LAD980879449 By: 1)ddJcfJJv Date: -----=-~L-----13.__L_0___'_11__ _ MfChaelHebert, U.S. EPA Remedial Project Manager By Date: f UI &f4; ~ ----4//3~~---------- Cathy Gilmore, U.S. EPA Section Chief, LouisianalNew Mexico/Oklahoma Section Date: Donald Williams, U.S. EPA -»';----/------+---/(n- B~;;fanCh Date: -----;~~,-------g,----v--(J~~-- 41i'£. Faultry, U.S. EPA / Associate Director, edial Branch Date: _?!----'--1-'---9tiJ__ B y : ~:::::::::~~~~~===-____ Date: ~/Il ! ( Mark Peycke, U. ----~,~~--------- Chief, Superfund Branch, Office of Regional Counsel Date: _0-'--U_7 <-----/I__f B Y ~Pam Phillips,~ ~ U.S. EPar Deputy Director, Superfund Division 3 CONTENTS Section Page LIST OF TABLES ....................................................................................................................................... iii LIST OF ACRONYMS ............................................................................................................................... iv EXECUTIVE SUMMARY .................................................................................................................... ES-1 1.0 INTRODUCTION ........................................................................................................................... 1 2.0 SITE CHRONOLOGY .................................................................................................................... 2 3.0 BACKGROUND ............................................................................................................................. 4 3.1 PHYSICAL CHARACTERISTICS .................................................................................... 5 3.2 LAND AND RESOURCE USE ......................................................................................... 5 3.3 HISTORY OF CONTAMINATION .................................................................................. 5 3.4 INITIAL RESPONSE ......................................................................................................... 5 3.5 BASIS FOR TAKING ACTION ........................................................................................ 6 4.0 REMEDIAL ACTIONS................................................................................................................... 7 4.1 SELECTED REMEDY ....................................................................................................... 7 4.2 REMEDY IMPLEMENTATION ....................................................................................... 8 4.3 OPERATION AND MAINTENANCE .............................................................................. 8 4.4 OPERATION AND MAINTENANCE COST ................................................................. 10 5.0 PROGRESS SINCE THE SECOND FIVE-YEAR REVIEW....................................................... 10 5.1 PROTECTIVENESS STATEMENT FROM SECOND FIVE-YEAR REVIEW ............ 10 5.2 SECOND FIVE-YEAR REVIEW RECOMMENDATIONS AND FOLLOW-UP ACTIONS ......................................................................................................................... 11 5.3 STATUS OF RECOMMENDED ACTIONS ................................................................... 11 6.0 FIVE-YEAR REVIEW PROCESS ................................................................................................ 12 6.1 ADMINISTRATIVE COMPONENTS ............................................................................ 12 6.2 COMMUNITY INVOLVEMENT ................................................................................... 12 6.3 DOCUMENT REVIEW ................................................................................................... 12 6.4 DATA REVIEW ............................................................................................................... 13 6.5 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENT REVIEW .. 14 6.5.1 Chemical-Specific Applicable or Relevant and Appropriate Requirements ........ 15 6.5.2 Action-Specific Applicable or Relevant and Appropriate Requirements ............ 16 6.5.3 Location-Specific Applicable or Relevant and Appropriate Requirements ......... 16 6.6 SITE INSPECTION .......................................................................................................... 16 6.7 SITE INTERVIEWS ......................................................................................................... 17 7.0 TECHNICAL ASSESSMENT ...................................................................................................... 18 7.1 QUESTION A: IS THE REMEDY FUNCTIONING AS INTENDED BY THE DECISION DOCUMENTS? YES. .................................................................................. 18 7.2 QUESTION B: ARE THE ASSUMPTIONS USED AT THE TIME OF REMEDY SELECTION