Explanation of Significant Differences

Ringwood Mines/Landfill Superfund Site

Borough of RingwoodPassaic County, New Jersey

EPARegion2 April 2015

INTRODUCTION

The purpose of this Explanation of SignificantDifferences (ESD) is to explain the changes madeby the U.S. Environmental Protection Agency(EPA) to the final soil remedy selected for theRingwood Mines/Landfill Superfund site in 2014.

Under Section 117 (c) of the ComprehensiveEnvironmental Response, Compensation, andLiability Act of 1980 (CERCLA or Superfund), asamended, EPA is required to publish an ESD when,after issuance of a Record of Decision (ROD),subsequent enforcement or remedial actions lead tosignificant, but not fundamental, changes in theselected site remedy. Sections 300.435(c)(2)(i) and300.825(a)(2) of the National Oil and HazardousSubstances Contingency Plan (NCP) set forth thecriteria for issuing an ESD and requiring that anESD be published if the remedy is modified in away that differs significantly in either scope,performance, or cost from the remedy selected inthe ROD for the site.

This ESD presents the details ofEPA's decision tochange to a contingency remedy identified in the2014 ROD. This ESD provides a brief history ofthe site, describes the original and contingencyremedies, and explains how, subsequent to thefinalization of the decision document, activities ledto the change to the contingency remedy.

EPA's June 2014 Operable Unit Two (OU2) RODfor the Ringwood Mines/Landfill Superfund siteselected, among other things, the excavation andoff-site disposal of an estimated 71,000 cubic yards

of contaminated fill material from the 0'ConnorDisposal Area (OCDA) (see Figure 1), placement ofat least six inches of topsoil throughout theexcavated area to enable revegetation ofthe OCDA,restoration of wetlands that would be disturbedduring implementation of this remedy andgroundwater monitoring in the OCDA until agroundwater remedy for the site is addressed in theOperable Unit Three (OU3) ROD.

The OU2 ROD also called for implementation ofAlternative 4A, Site Grading and PermeableEngineered Cap as a contingency remedy for theOCDA should the Borough of Ringwood advanceits plans to use a portion of the OCDA as theBorough's recycling center and provided assurancesthat the recycling center would be constructed in atimely manner.

This ESD serves to document EPA's decision toimplement the contingency remedy for the OCDA.

SUMMARY OF SITE HISTORY,CONTAMINATION PROBLEMS, ANDSELECTED REMEDY

The site is located in a historic iron mining districtin the Borough of Ringwood, Passaic County, NewJersey. The site is approximately 500 acres in sizeand includes 48 residential properties, an inactivemunicipal landfill, abandoned mine shafts, filledmine pits, an industrial refuse disposal area, smallsurficial dumps, a municipal recycling center and arugged, forested area within the Ringwood StatePark. The site is drained by four brooks that

ultimately lead to the Wanaque Reservoir, whichsupplies drinking water to much of northern NewJersey. The residents in the immediate area of thesite receive their water from municipal wells whichare unaffected by the site. The land whichcomprises the site has been utilized for the miningof iron ore almost continuously from the mid-1700sto the early 1900s.

From 1965 until about 1971, the site was used forthe disposal of waste materials from Ford MotorCompany's Mahwah facility, including cardboardand other packing materials, scrap car parts, paintsludge and scrap and dented drums containinghardened sealing and insulating material. Wastewas disposed of in two former iron mining pits(Peter's Mine Pit and the Cannon Mine Pit) as wellas a former mine tailing disposal area, now calledthe OCDA.

The results of a July 1982 Site Inspection conductedby the New Jersey Department of EnvironmentalProtection (NJDEP) identified levels of benzene,ethylbenzene, and xylene in water samples collectedfrom the Peters Mine airshaft, which led to theSite's inclusion on the National Priorities List(NPL) in 1983.

From 1984 through 1988, Ford implemented aRemedial Investigation (RI), completed aFeasibility Study (FS) and removed over 7,000cubic yards of paint sludge and associated soil fromthe Site.

In September 1988, EPA issued a ROD whichselected long-term monitoring of groundwaterand surface water as the remedy for the site.The site was deleted from the NPL in 1994,with the presumption that all paint sludge anddrums of hazardous substances had beenremoved from the site. The deletion wasfurther supported by the determination thatgroundwater at the site did not pose anunacceptable threat to human health and theenvironment.

In 1989,1995 and again in 1998, additionalpaint sludge was located at the site, promptingseveral additional removal actions by Ford.

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The site was restored to the NPL in September2006, which was prompted by the discovery ofadditional significant quantities of paintsludge at the site.

In 2005 and 2010, the Ford Motor Companyentered into enforcement agreements with EP Awhich required the performance of anadditional RI and FSs for the site.

The site has been divided into four Areas ofConcern (AOCs) as follows:

• Peters Mine Pit Area - includes waste,fill material and soil located in andimmediately adjacent to the formerPeters Mine Pit;

• Cannon Mine Pit Area - includeswaste, fill material and soil located inand immediately adjacent to the formerCannon Mine Pit;

• O'Connor Disposal Area - includeswaste, fill material and soil located inand immediately adjacent to the formermine tailing disposal area; and

• Site-Related GroundwaterContamination - includes anygroundwater contamination resultingfrom disposal activities at the site.

Based upon the results of an additional RIlFS, inJune 2014, the OU2 ROD was signed which calledfor, among other things, the selection of Alternative5A for the OCDA. Alternative 5A requires theexcavation and off-site disposal of an estimated71,000 cubic yards of contaminated fill materialfrom the OCDA, placement of at least six inches oftopsoil throughout the excavated area to enablerevegetation of the OCDA, restoration of wetlandsthat would be disturbed during implementation ofthis remedy and groundwater monitoring in theOCDA until a groundwater remedy for the site isaddressed in the OU3 ROD.

In September 2013 the Borough of Ringwood,which owns the land that comprises the OCDA,provided plans to EPA for a new Borough recyclingcenter in the OCDA. The Borough indicated thatAlternative 4A, Site Grading and PermeableEngineered Cap, would be an alternative that would

be protective and compatible with this intendeduse. The Borough also noted that the capping calledfor in Alternative 4A would create a level area nearthe center of the OCDA, facilitating construction ofthe proposed recycling facility. The Boroughfurther indicated that the new recycling facilitywould replace the existing recycling facility andthat the existing recycling facility property wouldbe converted to green space for use by thesurrounding community.

As discussed in the OU2 ROD, if the land use at theOCDA were to change so that a portion of theOCDA were to be reused as the Borough'srecycling center, many ofEPA's concerns thatinformed selection of the selected remedy,Alternative SA, would be addressed with respect tothat reused portion. Among the primary reasonsfor EPA's selection ofthe selected remedy areconcerns regarding the potential for unauthorizedaccess to the area and associated damage to the capwhich may result if a containment alternative wasselected. However, under the Borough's proposal,the portion of the OCDA that would be used for therecycling facility would be capped with asphalt,which would mitigate concerns regarding damage tothe cap. Furthermore, the routine presence ofBorough employees at the recycling center woulddiscourage unauthorized access to this property.The Borough has also communicated its view thatthe existing recycling facility property would be abetter greenspace asset than the sloped property thatwould remain at the OCDA if the selected remedywere to be implemented.

DESCRIPTION OF SIGNIFICANTDIFFERENCES AND THE BASIS FORTHOSE DIFFERENCES

The OU2 ROD indicates that EPA would select thecontingency remedy as the remedy for the OCDAand appropriately document the selection of thecontingency remedy, if the following occurred:

(A) The Borough provides EPA with the followingwithin six months of the date of the OU2 ROD: (1)detailed engineering plans for the new recyclingcenter; (2) financial assurance(s) indicating thatsufficient funds will be available for construction of

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the recycling center; and (3) assurances andsupporting documentation indicating that theconstruction of the contingency remedy, includingthe recycling center, can and will be completedwithin either a shorter or, at least within acomparable timeframe than it would take toimplement the selected remedy, described above;and

(B) EPA determines that the information andassurance( s) that the Borough has submitted toEPA, as described above, are sufficient to allow thecontingency remedy to be implemented.

On December 19, 2014, the Borough of Ringwoodsubmitted documentation to EPA to attempt todemonstrate satisfaction of the aforementionedthree conditions for selection of the contingencyremedy. Documentation submitted by the Boroughincluded, but was not limited to:

(1) Ten drawings prepared by Engineering andLand Planning Associates, Inc., signed onDecember 12,2014, which provide detailedengineering plans for the new Borough recyclingcenter;

(2) A signed and notarized document entitled,"Declaration of Financial Assurance Relating to theMunicipal Recycling Center at the RingwoodMines/Landfill Superfund Site," dated December18,2014. This document notes that Ford hasreserved and committed $1.5 million to completethe construction of a new recycling center at theOCDA, should the contingency remedy be selectedby EPA; and

(3) A document entitled, "Ringwood Mines DraftTimeline Comparison for 0'Connor Disposal AreaAlternatives 4A and SA," dated December 18,2014.This document estimates that construction of theselected remedy would take 524 days whileconstruction of the contingency remedy and the newrecycling center is estimated at 262 days.

EPA has received and reviewed the materialssubmitted by the Borough of Ringwood and hasdetermined that the information and assurances thatthe Borough submitted has satisfied the criteria setforth in the OU2 ROD to allow the contingency

remedy to be implemented. Therefore, EPA hasselected the contingency remedy, as specified in theOU2 ROD, as the remedy to be implemented in theOCDA.

The contingency remedy, as specified in the OU2ROD, includes the following components:

• Consolidation of fill from the fringe areas ofthe OCDA to the center of this area toprovide level land which would permit reuseof this area;

• Installation of a minimum two-foot thickengineered permeable soil cap over theconsolidated fill materials, which willconsist of a geotextile fabric, 18 inches ofclean soil and six inches of top soil;

• Placement of six inches of clean fill inexcavated areas beyond the engineered capwhere soil/fill was removed forconsolidation under the cap to ensure properdrainage and a suitable substrate forplanting;

• Revegetation of the engineered soil cap andthe surrounding fill areas;

• Restoration of wetlands in the OCDA whichwere disturbed during implementation of theselected remedy, in coordination with theNJDEP's Land Use Program;

• Implementation of engineering controls,such as the installation of fencing and theplacement of boulders, to restrict access tothe capped area;

• Implementation of institutional control(s),such as deed notice(s), to maintain theintegrity of the cap;

• Long-term monitoring and maintenance ofthe capped area to ensure the integrity of thepermeable cap; and

• Monitoring of groundwater quality in theOCDA until a groundwater remedy isselected for the site.

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SUPPORT AGENCY COMMENTS

The NJDEP, after careful consideration of thecontingency remedy, supports this ESD, since thecontingency remedy is protective of human healthand the environment, and because the Borough ofRingwood and Ford Motor Company havecommitted to restore the current location of theBorough Recycling Center to a natural, green spaceecosystem of similar size and composition to thestream buffer zone that the OCDA currentlyoccupies.

FIVE-YEAR REVIEWS

Because the selected remedy, as modified by thisESD, will result in hazardous substances, pollutants,or contaminants remaining on-site above levels thatallow for unlimited use and unrestricted exposure, astatutory review will be conducted within five yearsafter initiation of the remedial action to ensure thatthe remedy is, or will be, protective of human healthand the environment.

AFFIRMATION OF STATUTORYDETERMINATIONS

The EPA and NJDEP believe that the remedy, asmodified, remains protective of human health andthe environment, complies with federal and staterequirements that are applicable or relevant andappropriate to this remedial action, and is cost-effective. In addition, the modified remedy utilizespermanent solutions and alternative treatmenttechnologies to the maximum extent practicable forthis site.

PUBLIC PARTICIPATION ACTIVITIES

Pursuant to NCP §300.825(a)(2), this ESD willbecome part of the Administrative Record file forthe site. The Administrative Record for the remedialdecisions related to the site is available for publicreview at the following locations:

u.S. EPA Records Center, Region 2290 Broadway, 18th Floor.New York, New York 10007-1866(212) 637-4308Hours: Monday-Friday - 9 am to 5 p.m., byappointment.

Ringwood Public Library30 Cannici DriveRingwood, New Jersey 07456Hours: Monday - Thurs. lOam to 9pm, Friday lOam- 5pm, Saturday lOam - 4pm

The EPA and NJDEP are making this ESDavailable to the public to inform them of the changemade to the remedy. Should there be any questionsregarding this ESD, please contact:

Joseph GowersRemedial Project ManagerNew Jersey Remediation Sectionu.S. Environmental Protection Agency290 Broadway, 19th FloorNew York, New York 10007-1866(212) 637-4413gowers.joe@epa.gov

With the publication of this ESD, the publicparticipation requirements set out in §300.4-35(c)(2)(i) of the NCP have been met.

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCYREGION II

DATE:

SUBJECT: Issuance of an Explanation of Significant Differences to Implement a Contingency Remedy forthe Ringwood Mines/Landfill Superfund Site, Ringwood, New Jersey

FROM: Doug Garbarini, ChiefNew York Remediation Branch

TO: Walter E. Mugdan, DirectorEmergency and Remedial Response Division

Please find attached for your approval an Explanation of Significant Differences (ESD) for theRingwood Mines/Landfill Site (Site), located in Ringwood, Passaic County, New Jersey. TheJune 30, 2014 Operable Unit Two Record of Decision (OU2 ROD) specifies criteria that need tobe met in order to implement a contingency remedy for the O'Connor Disposal Area (OCDA) ofthe Site. EPA has reviewed documentation submitted by the Borough of Ringwood and hasdetermined that this information satisfies the criteria specified in the OU2 ROD forimplementation of the contingency remedy. Therefore, this ESD has been prepared to implementthe contingency remedy for the OCDA.

ac owledge your approval of the attached ESD by signing below.

Walter E. MugdDirector, Emergency and Remedial Response Division