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RECORD OF DECISIONOPERABLE UNIT THREE

June 1994

Reeves Southeastern Superfund SiteHillsborough County, Florida

REGION IVAtlanta, Georgia

10489509

DECLARATION OF THE RECORD OF DECISION

SITE NAME AND LOCATION

Reeves Southeastern Corporation SiteHillsborough County, Florida

STATEMENT OF BASIS AND PURPOSE

This Record of Decision (ROD) document presents the selectedremedial action for the Reeves Southeastern Corporation site inHillsborough County, Florida. This ROD was developed inaccordance with the Comprehensive Environmental Response,Compensation and Liability Act (CERCLA) of 1980, as amended bythe Superfund Amendment and Reauthorization Act (SARA) of 1986,42 U.S.C. 9601 et seq., and to the extent practicable, theNational Oil and Hazardous Substances Pollution Contingency Plan(NCP) (Section 105 of CERCLA), 40 CFR Part 300. This ROD isbased on the Reeves Southeastern Site Operable Unit ThreeAdministrative Record.

The State of Florida, as represented by the Florida Department ofEnvironmental Protection (FDEP), has been the support agencyduring the Remedial Investigation and Feasibility Study processfor the Reeves Southeastern site. In accordance with 40 CFR300.430, FDEP, as the support agency, has provided input duringthis process. Based upon comments received from FDEP, it isexpected that concurrence will be forthcoming; however, a formalletter of concurrence has not yet been received.

DESCRIPTION OF THE REMEDY

This operable unit is the third of three operable units plannedfor the site. The first operable unit selected for this siteinvolves the remediation of the soils/sediment on the site. Thesecond operable unit addresses the contamination in the northernsurficial aquifer groundwater underlying the site.

The major components of the selected remedy include:»Vt

f&"•-'**

o Iftf Action;

o Long-Term Monitoring of the North Wetland and unnamedcreek;

DECLARATION STATEMENT

The EPA has determined that no action is necessary to ensure theprotection of human health or the environment. The five yearreview will apply to the no action remedy because monitoring ofthe North Wetland and unnamed creek will be performed.

John H. Hankinson, J». DateRegional Administrator

•?/.'!'*•

DECLARATION OF THE RECORD OF DECISION

SITE NAME AND LOCATION

Reeves Southeastern Corporation SiteHillsborough County, Florida

STATEMENT OF BASIS AND PURPOSE

This Record of Decision (ROD) document presents the selectedremedial action for the Reeves Southeastern Corporation site inHillsborough County, Florida. This ROD was developed inaccordance with the Comprehensive Environmental Response,Compensation and Liability Act (CERCLA) of 1980, as amended bythe Superfund Amendment and Reauthorization Act (SARA) of 1986,42 U.S.C. 9601 et seg., and to the extent practicable, theNational Oil and Hazardous Substances Pollution Contingency Plan(NCP) (Section 105 of CERCLA), 40 CFR Part 300. . This ROD isbased on the Reeves Southeastern Site Operable Unit ThreeAdministrative Record.

The State of Florida, as represented by the Florida Department ofEnvironmental Protection (FDEP), has been the support agencyduring the Remedial Investigation and Feasibility Study processfor the Reeves Southeastern site. In accordance with 40 CFR300.430, FDEP, as the support agency, has provided input duringthis process. Based upon comments received from FDEP, it isexpected that concurrence will be forthcoming; however, a formalletter of concurrence has not yet been received.

DESCRIPTION OF THE REMEDY

This operable unit is the third of three operable units plannedfor the site. The first operable unit selected for this siteinvolves the remediation of the soils/sediment on the site. Thesecond operable unit addresses the contamination in the northernsurficial aquifer groundwater underlying the site.

The major jijMponents of the selected remedy include t

o •$! Action;

o Long-Term Monitoring of the North Wetland and unnamedcreek;

TABLE OF CONTENTS

1.0 SITE NAME, LOCATION. ASP DESCRIPTION I

2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 3

3.0 HIGHLIGHTS OF COMHONITT PARTICIPATION 5

'4 . 0 SCOPE AMD POLE OF OPERABLE UNIT, ..............................6

5.0 SUMMARY OF SITE CHARACTERISTICS 75.1 Scope 75.2 General Site Characteristics 75.3 Results of VIS and Additional Studies 8

6.0 SUMMARY OF SITE RISKS 96.1 Human Health Risks 9

.1.1 Scope 9

.1.2 Chemicals or Concern Identification 13

.1.3 Exposure Assessment Information 14

.1.4 Toxlclty Assessment Information 14

.1.5 RJ.sk Characterisation Information 202 Environmental Risks , 22.2.1 Scope 22.2.2 Bioaccumulation 25.2.3 environmental Toxlclty Assessment * 25

6.3 Uncertainties and Limitations in the BRA Process 26

7.0 DESCRIPTION OF ALTERNATIVES 277.1 Applicable or Relevant and Appropriate Requirements 277.2 Description Of Alternatives 277.2.1 Description of Process '. 277.2.2 Alternative 1A - Ho Action 347.2.3 Alternative IB - Ho Action/Monitoring 347.2.4 Alternative 2 - Filling of Wetland and Unnamed Creek 347.2.5 Alternative 3A, 3fl, 3C - Excavation of Sediments 34

8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 358.1 Criteria for Evaluating Remedial Alternatives 358.2 Threshold Criteria 358.2.1 Overall Protection of Human Health and the

Environment 358.2.2 Compliance with ARARs 378.3 Primary Balancing Criteria 378.3.1 LojuhAuai Effectiveness 378.3.2 JtedOBaa of Toxlclty f Mobility or Volume 378.3.3 Sft4̂ BpH> Effectiveness 37

0.4 Modiryiag'criteria!'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. '.388.4.1 State Acceptance 388.4.2 Community Acceptance 38

_9.1 Selection of Remedy9.2 Major Coqponaata of Remedy.9.3 Compliance w±th ARARs

.38

.38

.39

.40

10.0 DOCUMENTATION Of SIGNIFICANT CHANGES. .40

» ̂

PAOS fJ Area Map 22 Sampling Locations .10

/ .3 Criteria for Evaluation of Remedial Alternatives.36

TABLES1 Sediment Data Summary 112 Surface Water Data Summary 123 Summary of Chemical Concentrations of the COCs

in the North Wetlands 154 Summary of Exposure Pathways for the

North Wetlands 165 Assumptions Used in Estimating Exposure via

Ingestion of Sediment 176 Assumptions Used to Estimate Exposure via

Dermal Contact of Sediment 107 Assumptions Used to Estimate Exposure via

Dermal Contact with Surface Water 198 Summary of Chronic Rfds and Slope Factors 219 Cancer Risk by Individual Pathway 2310 Hazard Index Estimates by Pathway .2411 Potential Chemical Specific ARARs 2812 Location Specific ARARs 29 - 3113 Action Specific .ARARs 32 - 33

" "" '"RECORD" OF' DECISION ""' il- 'OPERABLE UNIT THREE

REEVES SOUTHEASTERN SUPERFUND SITEHILLSBOROUGH COUNTY, FLORIDA

DECISION SUMMARY

1.0 SITE NAME, LOCATION. AND DESCRIPTION

The Reeves Southeastern Corporation Site is located in centralHillsborough County, Florida. The site consists of twofacilities located across the road from each other: the 17.36acre Reeves Southeastern Galvanizing (SEG) facility on the northside of State Road (SR) 574 approximately 1200 feet west ofFaulkenburg Road; and the 11.6 acre Reeves Southeastern Wire(SEW) facility located on the south side of SR 574 approximately600 feet west of Faulkenburg Road. Originally, just the SEGfacility was listed in the National Priorities List (NPL) and itwas considered to be the site. Because contamination wasdiscovered on the SEW facility during the RI, both facilities arenow considered part of the site. Both facilities are still inoperation. Two additional Superfund sites are located in thearea. These are the Peak Oil site, which is located immediatelywest of the SEW facility and the Bay Drums site, which is locatedimmediately west of the Peak Oil site. Figure One, taken fromthe Reeves site source characterization Feasibility Study (FS),shows a map of all three sites.

Currently, the area north of the SEG facility is Sabal IndustrialPark, a development containing various light industrial andoffice buildings. The area south of the Reeves site.is generallyundeveloped, but does encompass, about 400 acres owned byHillsborough County that contains a wastewater treatment plant, asolid waste resource recovery facility and an area designated asthe potential location of a new jail. There is no residentialdevelopment in the immediate vicinity; the nearest being .25miles east of the SEW facility. According to the Official ZoningAtlas for Hillsborough County (1985), the Reeves, Peak Oil andBay Drums properties are all currently zoned for lightmanufacturing. All of this information would indicate that it isunlikely that the future use of the property would includeresidential development.

The largote .building on the SEG facility is where commercialsteel prodHfert* are pre-treated and galvanized. There is also asmall offlpfc building and maintenance shed. A 300 gallon tanksituated in a small rectangular area in the northwest corner ofthe maintenance shed was used in the 1960s as a wastewater catchbasin during electroplating. Two inactive liquid wastepercolation/evaporation ponds are located in the north-centralpart of the property area. A waste-water pretreatment facilityand a double-lined storage basin for settled solids are locatedon the northeast portion of the SEG.

-i-

g. s

LEGEND:

.V

PEHCOOIION/IVAPORA MOMPONDS (UNLINED)

SOLIDS SIOftACCBASIN (LINED)

LACOON (UNLINEO)

t?

LACOON (UNUNCD)

PCRCOLAriON/CVAPOAAriONPONDS (UNLINEO)

or

lOPOC&M'inC CPNKMiK(.' fO'Jl ConlOUH(fttl *UOv[

The largest building on the SEW fac£lity~is"whefe titeel wire isdrawn, weaved into chain link fence, pro-treated and galvanized.The smaller building on the facility is an office building.There are three former percolation/evaporation ponds: one on thecentral western edge of the property (now backfilled); and two onthe southwestern corner of the property. There are severaloffsite wetlands near the three sites. The North Wetland is theone that is associated with the Reeves site.

Aerial photographs from the 1950s show that the North Wetland andunnamed creek predated the SEG facility. In the late 1970s, thedevelopers of Sabal Industrial Park submitted a permitapplication for the construction of a stormwater managementsystem for the proposed development. The Permit ApplicationAppraisal, dated May 9, 1978, included the unnamed creek as apart of the system and defined the unnamed creek as a swale. Aletter from FDER dated December 31, 1981 states that the NorthWetland drainage system is a part of the already existingstormwater management system for Sabal Park and a letter from theSouthwest Florida Water Management District (SWFWMD) dated April18, 1984 reconfirms this. The plat for the Sabal Park MasterDrainage Plan that was submitted to SWFWMD in 1984 clearly showsthat the unnamed creek and, by extension, the North Wetland areconsidered by Sabal Park to be a part .of its stormwatermanagement system. In the early 1990s, after the sampling forthe WIS had taken place, the unnamed creek was dredged by anunknown party.

2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES

The SEG facility was originally, built and operated as AcmePlating and Galvanizing Company in the mid-1960s. In 1970, thefacility was acquired by Metal Coatings, Inc, which merged intothe Southeastern Galvanizing Corporation in 1971. Throughinternal reorganizations, Southeastern Galvanizing Corporationbecame the Southeastern Galvanizing Division of ReevesSoutheastern Corporation. The SEG facility utilized twodepressions as percolation/evaporation ponds for theirwastewater. The ponds were later enlarged to their present sizeof 100' by 100' each, with 5' berms surrounding them and a belowgrade depth of about 10'. The ponds were used for disposing ofprocess wa*tewater until 1982, when the current wastewaterpretreatagfttp system was installed. Wastewater from the facilityis now dlfS&arged into the local publicly owned treatment works(POTW)

The SEW facility was originally built in 1955 and operated byFlorida Wholesale Fence, Inc., a subsidiary of Reeves Fences,Inc. Through two mergers, Florida Wholesale Fence became the .Southeastern Wire Division of Reeves Southeastern Corporation.The first percolation/evaporation pond for disposal of SEW'swastewater was built in 1955 and was used until it was backfilled

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lh'the"lat:e-1960&V Its dimensibhs were •approximately' 75'' longand 25' wide and was located along the central western border ofSEW. A second pond was constructed prior to 1969; it wassubdivided in 1975 to form the two current ponds in the southwestcorner of the facility. Both ponds are approximately 35' by 35',and are surrounded by a 3' berm. The ponds were excavated to adepth of 3'. Discharge into these ponds ceased in 1980 when SEWbegan using its wastewater pretreatment program. Discharge fromthis facility also goes into the local POTW.

The U.S. EPA conducted a site investigation in 1981 thatindicated elevated metal levels in surface water and groundwaterat the SE6 facility. Subsequently, the Florida Department ofEnvironmental Protection (FDEP) (formerly the Florida Departmentof Environmental Regulation) conducted a survey of the types andmagnitude of chemical contamination at SE6; this survey resultedin the 1982 placement of SE6 on EPA's National Priorities List(NPL). Reeves contracted in 1985 with CH2MHill for a terrainconductivity survey utilizing electromagnetic inductiontechnology to be performed at both SEW and SE6. The resultsindicated a possible groundwater contamination problem in thesurficial aquifer underneath both facilities.

In 1988, the Reeves Southeastern Corporation and a group ofpotentially responsible parties (PRPs) for the adjacent Peak Oilsite signed individual Administrative Orders of Consent (AOCs) toperform source characterization Remedial Investigations andFeasibility Studies (RI/FSs) at their respective sites. Underthe AOCs, the Peak Oil PRPs agreed to perform a sourcecharacterization RI/FS at the Peak Oil site and the ReevesSoutheastern Corporation would perform a source characterizationRI/FS at its SEG and SEW facilities. EPA decided to perform asource characterization RI/FS at the Bay Drums site. The resultsof,the source characterization RI/FS for the Reeves site and theresulting remedy decision is documented in the Operable Unit One- Record of Decision. October 1992. That remedy decisionconsists of the following! excavation of contaminated soils andsediments on the SEG and SEW facilities; backfilling of excavatedareas with clean fill; solidification/stabilization of thecontaminated soils and sediments; disposal of the solidifiedmaterial above the water table on the SEG facility; and cappingof the solidified material with a low permeability cap.

In additiqttb-.to the source control RI/FSs, the Peak Oil and BayDrums PRPipiind the Reeves Southeastern Corporation agreed in aseparate AOC to perform.an area-wide groundwater RI/FS. Theresults of the groundwater RI/FS and the resulting remedyselection on the groundwater underlying the Reeves site aredocumented in the operable Unit Two - Record of Decision*September 1993. The remedy decision consists of the following»natural attenuation of the Northern Surficial Aquifer;installation of additional monitor wells in the Northern

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Surficial Aquifer; prevention of discharge of groundwater fromthe Northern Surficial Aquifer into the surface water in theunnamed creek; installation of a monitor well in the UpperFloridan Aquifer in the general vicinity of the former productionwells on the Reeves SEG facility; implementation of an intensivewell survey within a one mile radius of the site; and completionof the remedial design for the contingency remedy. Thecontingency remedy, to be implemented 2.6 years after completionof the OU1 remedy should the OU2 remedy be failing, is to pumpand treat the groundwater in the Northern Surficial Aquifer andthen discharge the treated water into the POTW.

EPA conducted the Wetlands Impact Study (WIS) at the same timethe area-wide groundwater RI/FS was being conducted by Reeves andthe Peak Oil/Bay Drums PRPs. The risk assessment was provided bythe PRP groups as a part of the area-wide RI. The FS wasdeveloped by EPA personnel information provided by the PRP groupsand the WIS.

In February 1993, Reeves signed a Modification to the site-specific RI/FS AQC under which Reeves agreed to perform theRemedial Design for the OU1 remedy. For the Reeves OU1 and OU2remedies, EPA issued a special notice letter (SNL) to the ReevesSoutheastern Corporation on September 30, 1993. The SNL offeredReeves the opportunity' to perform the OU1 and OU2 remedies andreimburse outstanding EPA past costs relating to the site.Reeves and EPA Region IV signed a Consent Decree (CD) in whichReeves agreed to perform the work, pay EPA's future oversightcosts and reimburse EPA's past costs. The past cost amount was$297,778.28. The CD was referred to the Department of Justice(DOJ) on April 21, 1994.

3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

Community relations for the Reeves Site has, for the most part,been handled in conjunction with the Peak Oil and Bay Drumssites. Interest in the Reeves site itself has been minimal.What community interest that has been noted was focused on EPAactivities at the other two Super fund sites. This is probablydue to the removal at Peak Oil, where contaminated sludge from alagoon was incinerated, and the removal at Bay Drums, where alarge pile of roofing shingles had to be removed from the site inorder to cgpduct the RI/FS.

'The sourcfl̂ icontrol RI/FS was completed and presented to thepublic in Angnst 1992. A public meeting was held at the BrandonCommunity College on August 18, 1992, at which the Agency'spreferred alternative for the Reeves source control cleanup planwas presented. The preferred alternatives for the sources at thePeak Oil and Bay Drums sites were also presented at this meeting.The preferred alternative was, in fact, the cleanup plan that wasselected in the October 1992 ROD. The area-wide groundwater

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RI/PS-was- completed and presented ̂ a the public in February 1993.The public meeting was held on February 24, 1993. The preferredalternative presented at this meeting for the Reeves site was apump-and treat remedy for the northern surficial aquifer. Theselected remedy in the ROD was natural attenuation, with thepump-and-treat system selected as a contingency remedy. Inaddition, measures will be taken in the design process to preventthe surficial aquifer from draining into the unnamed creek. Theonly written comments received on the Reeves site from eithercomment period came from the Reeves Corporation itself.

The North Wetland WIS/FS and Proposed Plan for the ReevesSoutheastern Site were released to the public on April 30, 1994.These documents were released in conjunction with the Peak Oil/Bay Drums Central and South Wetlands WIS/FSs and Proposed Plansand were made available to the public in both the AdministrativeRecord and the information repository maintained at the EPADocket Room in Region IV and at the Brandon Public Library. Thenotice of availability of these documents and announcement of thepending public meeting was published in the T̂ mp* Tribune on May3, 1994. A public comment period was held from May 2 to May 31,1994. The public meeting was held on May 11, 1994. At themeeting, representatives from EPA presented the two ProposedPlans and answered questions regarding the problems at the threesites and the wetlands remedial alternatives under considerationfor the North, Central and South Wetlands. A response to thecomments received for the North Wetland during the public commentperiod is included in the Responsiveness Summary, which isAppendix A of this ROD. This decision document presents theselected remedial action for the North Wetland and unnamed creek.at the Reeves Southeastern Site, in Hillsborough County, Florida,chosen in accordance with CERCIA, as amended by SARA, and, to theextent practicable the National Contingency Plan. The decisionfor this site is based on the Administrative Record.

4.0 SCOPE AND ROLE OF OPERABLE UNIT

As with many Superfund sites, the problems at the ReevesSoutheastern site are complex. As a result, EPA divided the workinto three operable units (Oils). These are:

o OH Ones Contamination in the soils and sediments;"••'i «•

o OÔ Jfcos Contamination in the groundwater;

o OO Threei Contamination in the North Wetland and unnamedcreek.

OU One has been addressed in the Reeves OU One - ROD. October1992. OU Two has been addressed in the OU Two - ROD, September1993. The Reeves OU Three will address the North Wetland andunnamed creek. This is planned to be the final Operable Unit for

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the Reeves site. The Peak Oil/Bay Drums OU Four will address theCentral and the South Wetlands. The Peak Oil and Bay Drums OUFour will be selected in a separate ROD.

5.0 SUMMARY OF SITE CHARACTERISTICS

5.1 Scope

This section will discuss general site characteristics andoutline the results of the WIS and other North Wetland samplingevents. The issue of source contamination is addressed in theOperable Unit One - Record of Decision; the issue of groundwatercontamination is addressed in the Operable Unit Two - Record ofDecision.

5.2 General Site Characteristics

Climate in the Tampa area is characterized by mild winters andrelatively long, humid, warm summers.. Spring and fall tend to bedry, with the majority of the rainfall in the summer. Thegeneral topography is flat. The land use in the area is eitherindustrial or undeveloped, with the nearest single familyresidential area being 0.25 miles east of the SEW facility.Topographically, surface elevations on the SEG facility rangefrom 36 feet above mean sea level (MSL) at the southern boundaryto 26 feet above MSL on the northern boundary. The southernportion of the SEW facility slopes gradually toward the south andsouthwest toward small wetland areas. The area around the twofacilities is relatively flat.

•

The groundwater system beneath the area consists of two majorwater bearing unitst a surficial aquifer and the Floridanaquifer system. The surficial aquifer, which is defined as aClass IIB aquifer, is from 8.5 feet to 37 feet thick with asaturated thickness of about 5 to 25 feet. It is separated fromthe Floridan aquifer by the Hawthorne formation, a clayey low-permeability layer from 16 to 40 feet thick. The surficialaquifer is hydraulically connected to the wetlands near the siteand the flow direction varies seasonally. Water levels alsofluctuate seasonally and change rapidly in response to rainfalland other natural influences. Although regionally the Floridanaquifer flows to the west-southwest, in the vicinity of the sitethe flow 4ttK«ction shifts to the northwest. This is thought tobe due tô Rt* proximity of the site to the Tampa Bypass Canal,which IMfTdly cuts into the low-permeability layer and reachesthe upper̂ fldridan aquifer in several places. The Floridanaquifer ia the primary source of drinking water and water forindustrial use in Hillsborough County, however, there are nopermitted wells which are used for drinking water in the generalvicinity of the site. To EPA's knowledge, the surficial aquiferis not currently used for any purpose. It meets the criteria forclassification as a Class IIB aquifer under EPA's groundwater

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protection7'Strategy. A Class IIB'agti'ifer̂ iŝ &nSidered apotential drinking water source.

The North Wetland is located to the immediate west of the ReevesSEG facility. It is about 1.75 acres in size and is located inthe maintained right-of-way of power lines and is the only one ofthe studied wetlands with a surface water inlet and outflow.After rain events, surface water inflow originates in a ditchparalleling SR 574 and running west between the Peak Oil/BayDrums sites and the south side of the road. The topographiccontour of the SEW facility would tend to cause surface waterrunoff to the south of the plant, not into the ditch. This ditchis joined by runoff from the Peak Oil/Bay Drums sites via aseries of culverts that run from the sites under the CSX railroadand then into the drainage ditch. The surface water then runsthrough a culvert under SR 574 at the power lines and then entersthe North Wetland. It exits the North Wetland and flows in adrainage ditch northeast and crosses the northwest corner of theSEG facility, where it is joined by a drainage ditch carryingrunoff from the SEG facility. The drainage ditch (a.k.a theunnamed creek) then heads north, where it is joined by the runofffrom the parking lots of various other office buildings andanother road, and eventually flows into the retention pond forthe stormwater drainage system at Sabal Industrial Park. Theoutflow from the retention pond flows into the Tampa Bypasscanal. The classification of the wetland was conducted accordingto a U.S. Fish & Wildlife methodology. The vegetativeclassification is palustrine system, emergent/aquatic bed class.

5.3 Results of WIS and Additional Studies

The topography of the SEG site slopes toward the northwest. Thedrainage off the SEG facility is into a drainage ditch that runsfrom the east to the west of the facility, immediately south ofthe two ponds, then turns north and joins the, unnamed creekimmediately north of the northwest corner of the facility. Othersources of contamination for the North Wetland can potentially beidentified. In particular, stormwater in an urban settingcontains elevated levels of inorganics such as zinc, lead,copper, cadmium and chromium from vehicular use of highways andparking lots. The sources of such inorganics include vehicleparts such aa brakes, tires and hydraulic fluids, as well asdirect faljfjbat from the atmosphere and degradation of highwaymaterials £||

A limited Jnibunt of sampling done for the WIS tested materialfrom the site itself. Surface water from the two inactive pondsand soil from the eastern part of the SEG facility did not showsignificant toxicty to the test organisms. Sediments from the.SEG ponds, however, are highly toxic. Other onsite soil areasthat showed toxicity were the former drum storage area and theonsite drainage ditch. The onsite source areas that tested toxic

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will, be addressed by the Operable Unit One remedy that wasselected in the October 1992 Record of Decision.

Three phases of sampling were done for the North Wetland and theunnamed creek. Phase I sampling took place in November 1989 andPhase 2 sampling took place in January 1990. Phase 1 and Phase 2were composed of both surface water and sediment sampling. BothPhase 1 and Phase 2 data were used in the WIS. On its own,Reeves undertook a third phase of sampling. This data was takenin 1993 and consisted only of sediment sampling. The samplepoints are shown on Figure Two. The sediment data is reported inTable One and the surface water data is reported in Table Two.The data reported in these two tables have been narrowed down tothe data reported for the contaminants of concern (as selected inChapter Three of this FS). The entire range of results can befound in Tables 4.5 and 4.6 of the WIS. The levels of metalsfound in the North Wetland are comparable to those found in thedrainage ditch leading to it. The levels found during the WIS inthe unnamed creek, after being joined by drainage off the SEGfacility, were significantly higher than the levels in either theNorth Wetland or upgradient drainage ditch. However, since thefield work for the WIS was completed, the unnamed creek has beendredged by an unknown entity. Sampling performed on Reeves'behest by its consultant in 1993 indicate that the current levelsof contaminants of concern (COCs) in the unnamed creek aresignificantly lower than the levels found during the sampling forthe WIS. Surface water levels in the North Wetland andupgradient drainage were comparable; the levels weresignificantly higher in the unnamed creek. There are no 1993sample results for comparison purposes for the surface water.

The WIS concluded that the wetlands associated with the threeSuperfund sites provide a diversity for a balanced community ofplants and animals. The ecological functions of these wetlandswere rated as moderate to high. The apparent toxicity of thesediment does not appear to impair the wetland functions. On theother hand, the WIS showed that the unnamed creek associated withdrainage from the SEG facility was severely impacted by heavymetal contamination.

6.0 SUMMARY OF SITE RISKS

A baseline risk assessment (BRA) was conducted as part of the RIto estimate the health or environmental problems that couldresult if the Northern Wetland was not remediated. A BRArepresents an evaluation of the "No Action" alternative, in thatit identifies the risk present if no remedial action is taken.The assessment considers environmental media and exposure

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Station 10

Station B(OMC)

Station A(NOW) Station 1

Station 4

TABLE ONESediment Data Summary (MG/KG)

Station

Date 19-••••••••arsenic

cadmium

chromium

lead

mercury

nickel

zinc

4

BJjj^JJ

n.rni.e2.8N

92. 2N

860

.24

9.8

2960

6

320

1100

.4

19

4500

1

89••••••46N

2M

168N

3070

.16

71.9

4480M

93mm^5.2

K>I

TABLE TWOSurface Water Data Summary (U6/L)

Station

Date•••••••̂•••Ml

arsenic

cadmium

chromium

lead

mercury

nickel

zinc

4

UAE/J9Tir̂ P̂fvF— * . ,-.

—5.1

—--37.9

A (01-NOW)

11/30/89

3B

--

--

--NA

4. IB

48.7

B (01-UNC)

11/30/89

41. 2S

9.8

135

352

NA

155

172000

1/9/90__

--16

15

— —--11000

10

11/10/89__

—--5W

— —--1410

( — ) - non detect.B - Analyte found in associated blank as well as in sample.W - The post-digestion spike for furnace AA analysis is outside of the

85-115% control limits while sample absorbance is less than 50% ofthe spike absorbance.

patKvfays that-could'result""fri"uriacceptabr̂ levels of exposure 'In •'the foreseeable future. Data collected and analyzed during theRI provided the basis for the risk evaluation. The BRA processcan be divided into four components: contaminant identification;exposure assessment; toxicity assessment; and riskcharacterisation.

Two separate BRAs have been developed for this site: the firstdeveloped for the site-specific source control RI/FS; the seconddeveloped as part of the area-wide groundwater RI/FS. The sourcecontrol BRA is discussed in detail in the Operable Unit One ROD(October 1992) and the Northern Surficial Aquifer BRA isdiscussed in detail in the Operable Unit Two ROD (September1993). The BRA for the North Wetland and associated drainageditch was developed as a part of the area-wide BRA. This sectionwill discuss the BRA for the North Wetlands and associateddrainage system.

6.1.2 Chemicals of Concern Identification

Based on the study area data, the BRA selected chemicals ofpotential concern (COPCs) to focus on those likely to pose thegreatest threat to human health. The final list of COPCs for thesite-wide BRA included chemicals found on all three sites. Forreasons that are more fully explained in another Chapter, it hasbeen determined that the main contributor to any potentialproblem in the North Wetlands is the Reeves SEG facility.Therefore the initial selection of COPCs for the North Wetlandswould be the same as the COPCs identified in the Reeves SiteSource Characterisation Baseline Risk Assessment, February 1992.These COPCs are as followss

o arsenico cadmiumo chromiumo goldo leado mercuryo nickelo polychlorinated biphenyls (PCBs)o polynuclear aromatic hydrocarbons (PAHs)o 1,2.4-trichlorobenzeneo dfe-

•Jr1*'

•â ŜŜ J* — • * . . - -. '•• 4ll • ™* ••"• -• — . » » - * _ _ .*.».-, .- --,

the list because it was not found in the surface water or <sediment of the North Wetland. The final list of chemicals ofconcern (COCs) for the North Wetlands and associated drainageareas is aa followst

o arsenico cadmiumo chromiumo leado mercuryo nickelo zinc

Appropriate exposure point concentrations (EPC) were thencalculated for each COG. The COCs, the highest concentrationsdetected and the EPCs are found in Table Three.

6.1.3 Exposure Assessment Information

Generally, there are two scenarios developed for the BRAi acurrent use scenario; and a potential future use scenario. TheNorth Wetland presents a potential route of exposure throughwading and subsequent contact with chemicals in the water. Forthe current use scenario, exposures are assumed to occur totrespassers near the site. These individuals would be exposedthrough dermal contact and incidental ingestion of sediments andincidental contact with sediment. Direct ingestion of surfacewater was not considered because the water in the wetland wouldnot ordinarily be considered suitable for drinking. Incidentalingestion of the surface water was not considered beqause thewetland is too shallow for swimming. For the future usescenario, exposures are assumed to occur to children andteenagers living at the site. The exposure pathways would remainthe same. The summary of exposure pathways and scenarios can befound in Tables Four through Seven.

6.1.4 Toxicitv Assessment Information

Slope factors (SFs) have been developed by BPA's CarcinogenicAssessment Group for estimating excess lifetime cancer risksassociated with exposure to the potentially carcinogeniccontaminant(s) of concern. SFs, which are expressed in units of(mg/kg-da»|̂ , are multiplied by the estimated intake of apotential̂ puecinogen, in mg/kg-day, to provide an upper-boundestimate CjiLthe excess lifetime cancer risk associated withexposure at that intake level. The term "upper bound" reflectsthe conservative estimate of the risks calculated from the SF.Use of this approach makes underestimation of the actual cancerrisk highly unlikely. Slope factors are derived from the resultsof human epidemiological studies or chronic animal bioassays towhich animal-to-human extrapolation and uncertainty factors havebeen applied (e.g., to account for the use of animal data to

-14-

TABLE THREESummary of Chemical Concentrations of the Chemicals of

Concern in the North Wetlands

Chemical

Arsenic

Cadmium

Chromium

Lead

Mercury

Nickel

Zinc'S

Media

surfacewater

sediment

surfacewater

sediment

surfacewater

sediment

surfacewater

sediment

surfacewater

sediment

surfacewater

sediment

•urface:«terr sediment

Concentrationsurface water (ug/1)sediment (mg/kg)

HighestConcentrationDetected

3

12.7

ND

1.6

ND

108

5

266

ND

1.1

6

4.9

1410

3430

Exposure PointConcentration

2

8.7

— —

1.28

—

73.8

4

177

—

0.712

6

4.7

971

2200

-15-

TABLE FOURSummary of Exposure Pathways

for the North Wetland

Current Use Condition/Onsite Trespasser

Dermal contact with sediments

Dermal contact with surface waters

Incidental ingestion of sediments

Future Use Conditions/Onsite Resident

Dermal contact with sediments

Dermal contact with surface waters

Incidental ingestion of sediments

-16-

TABLE FIVEAssumptions Used to Estimate Exposure via

Ingestion of Sediment

Parameter

ChemicalConcentrations inSediment

Ingestion Rate(mg/day)

Exposure Frequency(days /year)

Exposure Duration(years)

Body Weight (kg)

Average Time (days)None arc inogensCarcinogens

Current UseTrespasser

Future Use Resident

see EPCs in Table Three

100

30

9

35

3,28525,550

100

30

9

35

3,28525,550

-17-

TABLE SIXAssumptions Used to Estimate Exposure via

Dermal Contact of Sediment

Parameter

ChemicalConcentrations inSediment

Skin Area Exposed(cm2)

Deposition Factor(mg/cmVday)

Exposure Frequency(days /year)

Exposure Duration(years)

Body Weight (kg)

Average Time (days)Noncarc inogensCarcinogens

Absorption Factor(unit less)

Current UseTrespasser

Future Use Resident

see EPCs in Table Three .

1520

0.2

30

9

30

3,28525,550

Chemical Specific

1520

0.2

30

9

30

3,28525,550

Chemical Specific

•4./;."•

-18-

TABLE SEVENAssumptions Used to Estimate Exposure via

Dermal Contact with Surface Water

Parameter

ChemicalConcentrations inSediment

Skin Area Exposed(cm2)

Dermal PermeabilityCoefficient (cm/hr)

Exposure Time(hour s /day)

Exposure Duration(years)

Exposure Frequency(days /year)

Body Weight (kg)

Average Time (days)NoncarcinogensCarcinogens

Absorption Factor(unit less)

Current UseTrespasser

Future Use Resident

see EPCs in Table Three

1520 1520

Chemical Specific

1

9

30

35

3,28525,550

Chemical .Specific

1

9

30

35

3,28525,550

Chemical Specific

-19-

predict effects on humans).. Reference doses (RfDs)̂ have .beendeveloped by EPA for indicating the potential for adverse healtheffects from exposure to contaminant(a) of concern exhibitingnonearcinogenic effects. RfDs, expressed in units of mg/kg-day,are estimates of lifetime daily exposure levels for humans,including sensitive individuals. Estimated intakes ofcontaminant(s) of concern ingested from contaminateddrinkingwater can be compared to the RfD. RfDs are derived fromhuman epidemiological studies or animal studies to whichuncertainty factors have been applied (e.g., to account for theuse of animal data to predict effects on humans). The ChronicDaily Intake (GDI) factors and the applicable route-specificSlope Factors for the chemicals of concern can be found in TableEight.

Environmental contamination with lead presents a problem in thedevelopment of the BRA. This is because the "normal" backgroundexposures to lead from sources such as food, water and airtogether contribute a substantial fraction of what EPA considersthe "acceptable" level of exposure and because the normallyaccepted measure of maximum allowable exposure is expressed notas a daily intake as is for most chemicals, but as aconcentration in the blood. EPA has examined several proceduresfor assessing lead and currently recommends the Uptake/Biokinetic(UBK) model be used to predict blood lead concentrationsresulting from environmental concentrations of lead. For thisBRA, version 0.4 of the UBK model was used. Blood levels forcancer risk is calculated from the following equations

Risk = GDI x SF

children from 0-6 years of age were modeled. Based on adirective from EPA Region IV, acceptable exposures were definedas those that result in predicted blood levels of less than 10ug/dl in at least 95% of the exposed children.

6.1.5 Risk Characterization Information

For carcinogens, risks are estimated as the incrementalprobability of an individual developing cancer over a life-timeas a result of exposure to the carcinogen. Excess life-timewhere s

•-*

risk = * «6it less probability (e.g., 2E-6) of an individualdevelopinf£cancer;

GDI = chronic daily intake averaged over 70 years (mg/kg-day);SF= slope-factor, expressed as (mg/kg-day)'1

These risks are probabilities that are generally expressed inscientific notation (e.g., 1E-6). An excess lifetime cancer riskof 1E-6 indicates that, as a reasonable maximum estimate, an

-20-

OiiU

TABLE EIGHTSummary of Chronic Rfds and Slope Factors

Chemical

Arsenic

Cadmium

Chromium

Lead

Mercury

Nickel

Zinc

Oral Toxicity

R£0(mg/kg/day)

3.00E-4

5.00E-4

5.00E-3

MA

3.00E-4

2.00E-2

3.00E-1

SFI/ (mg/kg/day)

1.75

NA

NA

NA

NA

NA

NA

Reference

IRIS

IRIS

IRIS

UBK modelusedinstead

HEAST

IRIS

IRIS

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individual has-a 1 in 1,00.0,000 additional .chance of developingcancer as a result of site-related exposure to a carcinogen overa 70-year lifetime under the specific exposure conditions at asite. The National Contingency Plan (NCP) states that sitesshould be remediated to chemical concentrations that correspondto an upper-bound cancer risk to an individual not exceeding 1E-6to 1E-4 excess lifetime risk.

The potential for noncarcinogenic effects is evaluated bycomparing an exposure level over a specified time period (e.g.,life-time) with a reference dose derived for a similar exposureperiod. The ratio of exposure to toxicity is called a hazardquotient (HQ). By adding the HQs for all contaminant(s) ofconcern that affects the same target organ (e.g., liver) within amedium or across all media to which a given population mayreasonably be exposed, the Hazard Index (HI) can be generated. .

The HQ is calculated as followss

Non-cancer HQ * COI/RfD

wherei

GDI = Chronic Daily Intake

RfD « reference dose; and

CDI and RfD are expressed in the same units and represent thesame exposure period (i.e., chronic, subchronic, or short-term).

Using these procedures, the lifetime cancer rates estimated to becaused by the surficial aquifer at these sites can be found inTable Nine. The hazard index due to ingestion of surficialaquifer water for both future use scenarios are greater than 1.0.The results can be seen in Table Ten. The results for both thecarcinogenic and the noncarcinogenic COCs were well within therange that EPA considers acceptable.

The UBK model predicts as its output a probability curve aroundthe geometric mean of the blood lead concentrations, from whichthe 95th percentile of the children's blood level concentrationcan be determined. The model calculated that the percent ofexposed cftttpUiren predicted to have blood levels below 10 ug/dl is99.70%.

6.2.1 Scope

The Area-Wide Wetland Impact Study (WIS) has two objectives! (1)to evaluate the ecological status of wetlands in the study area;and (2) to extend the toxicity testing to include possible source

-22-

TABLE NINECancer Risk by Individual Pathway

SCENARIO/EXPOSEDPOPULATION

RISK

CURRENT USE -

Dermal Contact,Surface water

Ingest ion, Sediment

Dermal Contact,Sediment

CHEMICAL

TRESPASSER

2E-9

1E-6

9E-8

FUTURE USE -

Dermal Contact,Surface water

Ingestion, Sediment

Dermal Contact,Sediment

• RESIDENT

2E-9

1E-6

9E-8

-23-

TABLE TENHazard Index Estimates by Pathway

SCENARIO/EXPOSEDPOPULATION

RISK

CURRENT USE -

Dermal Contact,Surface water

Ingest ion, Sediment

Dermal Contact,Sediment

CHEMICAL

TRESPASSER

0.0003

0.03

0.001

FUTURE USE -

Dermal Contact,Surface water

Ingest ion. Sediment

Dermal Contact,Sediment

- RESIDENT

0.0003

0.03

0.001

-24-

materials, soil, surface water and samples from the three sites.Since the source material from the Reeves site is addressed inOperable Unit One, that information is not further discussedhere.

Five wetlands were considered in the Area-Wide WIS. Thesewetlands ares The North Wetland; the Central Wetland; the SouthWetland; the Spray Field Wetland and the Cypress Pond Wetland.The latter two wetlands have no relation to any of the threesites, but instead were selected as comparison wetlands based ontheir hydrologic, vegetative, and sediment similarities to thethree site related wetlands.

6.2.2 Bioaccui"ulation

Overall, fish and crayfish sampled from the various wetland areasthat comprise this study were not impacted with a wide spectrumof chemicals at concentrations grossly over background. Theexception is the very high concentrations of iron and zinc foundin either fish or crayfish samples from the unnamed creek.Several inorganic analytes were widely present over the areasampled at concentrations moderately over background. Theseinclude aluminum, barium, copper, iron, manganese, titanium andzinc. Mercury concentrations in tissue analyzed were typically.lower than the national mean values. However, three of the foursamples of fish and crayfish taken from the reference wetlandsexceeded criteria proposed for the protection of birds that mayprey upon them.

6.2.3 Environmental Toxicity Assessment

This section discusses the results of the toxicologicalassessment performed to determine the impact constituents mayhave upon the biota. Samples of water, soils and sediment wereevaluated for toxicity based on acute and chronic test resultsafter various organisms were exposed to various site media.Water samples were tested using a bacterium, a freshwater algae,a small freshwater cladoceran, a freshwater fish and a species oflettuce. Sediment samples were eluated and the eluates producedwere tested using the same suite of organisms. The datagenerated indicated the following!

waters of the North, Central, and South Wetlandslittle toxicity to the organisms tested;

The sediments of each wetland area studied were atleast chronically toxic to daphnia;

The water and sediment of the unnamed creek at thenortheast corner of the Reeves SEG facility were toxicto almost all organisms tested;

-25-

o The sediments of the Cypress Pond were highly toxic tofish, daphnids, algea, and bacteria.

It should be noted that, since the WIS was completed, someunknown entity has dredged the unnamed creek area that was highlytoxic. As discussed in Section 5.3 of this ROD, data taken in1993 indicates the levels in the sediments are now lower than thelevels found in the WIS.

6.3 Uncertainties and Limitations in the BRA Process

Risk assessment provides a systematic means for organizing,analyzing, and presenting information on the nature and magnitudeof risks posed by chemical exposures. Nevertheless,uncertainties and limitations are present in all BRAs because ofthe quality of available data and the need to make assumptionsand develop inferences based on incomplete information aboutexisting conditions and future circumstances. Theseuncertainties and limitations should be recognized and consideredwhen discussing quantitative risk estimates. In general, theuncertainties and limitations in the BRA can be classified in thefollowing categories:

o environmental sampling and laboratory measurement;

o mathematical fate and transport modeling;

o receptor exposure assessment; and

o toxicological assessment.

The BRA is based on surface water and sediment data specific tothe sites gathered for the Area-Wide RI. The quality of datadepends on the adequacy of the set of rules or procedures thatspecify how a sample is selected and handled. The qualityassurance and quality control procedures used to minimizeuncertainties were based on Region IV procedures and werereviewed and approved in advance by EPA. They are described indetail in the RI Report.

The use of mathematical models to predict the fate and transportof chemicals is accepted by EPA, however, EPA does not specifywhich modrtls would be the most appropriate to use in any givensituationŝ Because few models have been authoritatively verifiedby field ojlifr vat ions, there is some uncertainty associated withtheir use.: Tradeoffs in the various models between simplicity,generality and accuracy are made on a site specific basis and arebased in part of the professional judgement of the technicalstaff involved in that particular site.

In the BRA, a large number of assumptions are made to assesspotential human exposure. In the absence of site specific data,

-26-

many of this BRA's assumptions were assumptions made by EPA. Ascan be expected any time that an assumption is made, there issome dispute as to the appropriate level of conservatism shouldbe factored into that assumption.

Available scientific information is currently insufficient toprovide a thorough understanding of all the toxic properties ofchemicals to which humans are potentially exposed. This makes itnecessary in some cases to infer these properties byextrapolating them from data obtained under other conditions ofexposure, generally in experimental laboratory animals. This mayintroduce uncertainties of two types into the BRAs those relatedto extrapolating from one species to another and those related toextrapolating from the high exposure doses usually used inexperimental animal studies to the lower doses usually estimatedfor human exposure situations.

7.0 DESCRIPTION OF ALTERNATIVES

7.1 Applicable or Relevant and Appropriate Requirements (ARARs)

Section 121 (d)(2)(A) of CERCLA specifies that SuperfundRemedial Actions must meet any Federal standard, requirement,criteria or limitation that is determined to be an applicable orrelevant and appropriate requirement (ARAR). ARARs fall intothree categories! contaminant-specific; location-specific; andaction-specific. Some rules do not specifically apply to aremedial action; however, because of the subject matter, they mayprovide some guidance in implementing a chosen RA. These rulesare called to-be-considered (TBCs). Potential ARARs.and TBCs canbe found in Tables Eleven through Thirteen.

7.2 Description of Alternatives

7.2.1 Description of Process

The contaminated material both at the site and in the NorthWetland and unnamed creek was evaluated in regard to theapplicability of the RCRA Land Disposal Requirements (LDRs) andit was determined that the RCRA LDRs were not an ARAR.

Based on the HIS results, EPA conducted a FS to identify andevaluate ojfbropriate remedial alternatives for minimizing risksto people'SpA the environment which could be caused bycontaminated surface water and sediments in the North Wetland andthe unnaaatT creek. EPA considered six remediation alternativesin the wetlands FS. Those six alternatives are listed in the FSas Alternatives LA, IB, 2, 3A, 3B and 3C. Two of thesealternatives are variations of the mandatory no actionalternative developed as required by the National ContingencyPlan (NCP). The no action alternative is developed to provide abaseline comparison of human health and environmental benefit to

-27-

TABLE ELEVENPotential Chemical-Specific ARARs and TBCs

Authority/Requirement • •

to

CWA Dredge and FillProvisions, 40 CFRPart 230

"• i

Restricts discharge ofdredge or fill materialthat will have anadverse impact onwetlands .

Relevant andAppropriate

Cons ider at ionin thedevelopmentofalternativesif remedyinvolvesdredging,filling, orotherexcavationactivitiesnear or inwetland

State

Florida Regulationof StormwaterDischarge, FAC 17-25.020(14)

Florida Regulationof StormwaterDischarge, FAC 17-25.020(16)

Florida Regulationof StormwaterDischarge, FAC 17-25.025

Definition of a"Stormwater DischargeFacility"

Definition of a "Swale"

Defines the design andperformance standardsrequired of a stormwatermanagement system.

Relevant andAppropriate

Relevant andAppropriate

Relevant andAppropriate

Cons ider at ionin thedevelopmentof remedialactionobjectives

Considerationin thedevelopmentof remedialactionobjectives

Considerationin thedevelopmentof remedialactionobjectives

Florida Rules onHazardous WasteWarning Signs, FAC17-736

Requires use ofappropriate warningsigns to inform publicof potentially harmfulconditions at the site,

Applicable May berequired onborders ofWetland

•j.

\

TABLE THIRTEENPotential Action-Specific ARARs and TBCs

Authority/Requirement

Description Status Consideration inthe FS

Federal

Identification andListing ofHazardous Waste, 40CFR Part 261

Identifies solidwastes which aresubject toregulation ashazardous waste

Applicable Considered indevelopment ofalternatives

Land DisposalRestrictions(LDRfl), 40 CFR 268

Regulations identifyhazardous wastesthat are restrictedfrom land disposaland define thecircumstances underwhich an otherwiseprohibited waste maycontinue to bedisposed.

Applicable Considered indevelopment ofalternatives

Water QualityStandards [CWA402(a)(l)]

Effluent limitationsare required toachieve allappropriate statewater qualitystandards

To Be Considered Considered inthe developmentof remedialalternatives

VI(•I

Florida SurfaceWater Standards,FAC 17-302.300

Florida HazardousWaste Rules, FAC17-730

Florida PermitRegulations, FAC17-4

State

Antidegradationpolicy for surfacewater quality.Prohibits dischargeof wastes intoFlorida waterswithout treatment toprotect beneficialuses

Florida hazardouswaste managementregulations

Establishesprocedures andrequirements toobtain a permit fromFDER

Relevant andAppropriate

Applicable

Applicable

Considered inthe developmentof remedialalternatives ifa remedyinvolvesdischarge tosurface waterthat areconsidered"waters of thestate"

Considered inthe developmentof remedialalternatives ifa remedyinvolveshazardous wastetreatment,storage ordisposal

Considered inthe developmentof remedialalternatives ifa Florida permitis required

.1:

l̂a provided by the active remediation alternatives.In conjunction with the source characterization and groundwaterRI/FSs, the North Wetland FS was developed. It assumes that theReeves selected source control and groundwater remedial actionswill be implemented.

7.2.2 Alternative 1A - No Action Alternative

For this alternative, no action would be taken to removeorcontrol any of the constituents of the sediments in the NorthWetland. The North Wetland and the unnamed creek would be leftin their present condition without disturbing the sediments. Ano action response provides a baseline assessment for comparisonwith other alternatives for the North Wetland and unnamed creekthat contain greater levels of response. Under no action, noremedial technologies would be implemented. However, these otheroperable units will improve the general conditions in the areaand thus should have a beneficial effect on the North Wetland.

TOTAL COST: $0

7.2.3 Alternative IB - No Action/Monitoring

Monitoring of the sediments would be conducted at intervals overa period of eight years to verify that the improved conditions inthe North Wetland is maintained. Under no action/monitoring, noremedial technologies would be implemented in the North Wetland.

TOTAL COSTi $39,860

7.2.4 Alternative 2 - Filling of Wetland and nnnamed

Filling of the North Wetland and the unnamed creek would involvethe removal of vegetation and placement of clean fill over areasof sediment that exceed the clean-up goals established by theEPA. It would further be necessary to construct a replacementdetention pond and replacement swale to handle the stormwatermanagement functions currently handled by the North Wetland andthe Drainage Swale. It may also be necessary to prepare andimplement a mitigation plan for the wetland that would bedestroyed.

TOTAL COST*

with land gferchase - $546,250without land purchase - $316,250

— Excavation of Sediments

These alternatives would involve the excavation of sediments.Excavated sediments would have to be placed on adjacent land ordisposed off site. Due to the low levels of constituents in the

-34-

sediments, it would not be necessary to place the excavated --sediments in a RCRA Subtitle c hazardous waste landfill or totreat the sediments by solidification or other means. However, .it would be necessary to determine a location for placement ofthe sediments. Three options have been identified aspossibilities. Those options are as follows:

o Alternative 3A - disposal in industrial waste landfillin Georgia;

o Alternative 3B - disposal in Springhill RegionalSanitary Landfill in Graceville, Florida;

o Alternative 3C - disposal in Pinellas County Landfillin St. Petersburg, Florida.

After completion of the excavation activities, the excavated areawould have to be backfilled with clean soil from an off-sitelocation, and the original contours would have to be established.It then would be necessary to replant the site with appropriatevegetation. Monitoring of the vegetation would be necessary fora period of three years to verify the establishment of theplants .

TOTAL COST:

o Alternative 3A - $2,526,550

o Alternative 3B - $2,003,300

o Alternative 3C - $2,311,644

8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

8.1 Criteria for Evaluatin gmedial Alternatives

In selecting its preferred cleanup alternative, EPA uses ninecriteria to evaluate each of the detailed alternatives developedin the FS. Those nine criteria are explained in more detail inFigure Three on the next page. The comparison of the sixalternatives using those criteria can be found in the remainderof Section 8 of this ROD.

8.2 Thraqhtfjtf Criteria

8.2.1 Overall Protection of H"*»J*" Health and the Environment

Protection of human health and the environment is provided byAlternatives 2, 3A, 3B and 3C. Alternatives 1A and IB provideslighter lesser protection of the environment in that thesealternatives would leave levels of two metals that are slightlyabove the ER-Ls.

-35-

REMEDIAL ALTERNATIVES

\ cleanup alternative, EPA uses the following criteria to evaluate each of -leloped in the Feasibility Study (FS). 'The first two criteria are essential and,

must be met before an alternative can be considered further. The next five are .used :to furtherevaluate EPA's proposed plan after public comment period has ended and comments from theState have been received. All nine criteria are explained in more detail hen. ' ***'

8.2.2 Compliance with ARARs

All of the alternatives meet ARARs.

8.3 Primary Balancing Criteria

8.3.1 Long—Terra Effectiveness and Permanence

Alternatives LA and IB have the least long-term effectivenessinthat nothing would be done. Alternative 2 has relatively morelong-term effectiveness because it prevents further degradationof the environment by preventing contact between the contaminatedmedia and the ambient environment. Alternatives 3A, 3B and 3Cprovide the most long-term effectiveness and permanence bypermanently removing the contaminated media from the site.

8.3.2 Reduction of Toxicity. Mobility, or VolnfQ

Alternatives LA and IB wouldn't result in any reduction oftoxicity, mobility or volume. Alternative 2 would result in areduction of toxicity and mobility by preventing contact betweenthe contaminated media and the ambient environment. Thisalternative would not affect volume. Alternatives 3A, 3B and 3Coffer the reduction of toxicity, mobility and volume bypermanently removing the contaminated media from the site.However, given the proximity of the North Wetland to the road,there is the possibility that this may not be a permanentcondition.

8.3.3 Short-Term Effectiveness

The short-term effectiveness of Alternatives LA and IB is higherthan that of Alternatives 2, 3A, 3B and 3C. The reason is thatthere is some minimal hazard to workers who would be involved inthe construction of these four alternatives.

8.3.4 Implement** hi 1 t'fcy

Alternatives LA and IB have no administrative barriers toimplementation. Alternative 2 may require mitigation, under theClean Water Act in addition to the alternative as described.Alternative* 2, 3A, 3B and 3C will require obtaining thepermissioB̂ jof the property owners of the land on which the NorthWetland ajM$ the unnamed creek are located. Alternatives 3A, 3Band 3C nuqfr require permits to transport and dispose of thecontaminated material.

8.3.5 Cost

The cost of the six alternatives are compared belowi

o Alternative 1A - $0

o Alternative- IB ^rc» ;.)•>•*. "$39̂ 860- •.•-

o Alternative 2w/ land purchase - $546,250w/out land purchase - $316,250

o Alternative 3A - $2,526,550

o Alternative 3B - $2,003,300

o Alternative 3C - $2,311,644

8.4 Modifying Criteria

8.4.1 State Acceptance

The State of Florida, as represented by the Florida Department ofEnvironmental Regulation (FDEP), has been the support agencyduring the Remedial .Investigation and Feasibility Study processfor the Reeves Southeastern site. In accordance with the 40 CFR300.430, FDEP, as the support agency, has provided input duringthis process. Based upon comments received from FDEP, it isexpected that concurrence will be forthcoming; however, a formalletter of concurrence has not yet been received.

8.4.2 Community Acceptance

The general public in the community expressed no major concernsabout the selected remedy during the public comment period. Thecomments are discussed in detail in the Responsiveness Summary,which is Appendix A of this ROD.

9.0 SELECTED REMEDY

9.1 Selection of Remedy

Based upon consideration of the requirements of CERCLA, the NCP,the detailed analysis of alternatives and public and statecomments, EPA has selected alternative IB, the NoAction/Monitoring remedy, as the remedy for this site. Resultsof the Wetlands Impact Study and the Area-Wide Baseline RiskAssessment indicated that no action is necessary at the site.However, bj|pause contaminants were found at levels abovebackgroundjJHJi wetland sediment and surface water, monitoring ofwetland BtjpEace water, sediment, and the nearby surficial aquifershall be conducted.

The purpose of the selected remedy is to assess the overallecologic status of the North Wetland and unnamed creek as theOperable Units One and Two remedies are being implemented.Monitoring data shall be compared to past wetland data, FloridaSurface Water Standards (F.A.C, 17-302) and NOAA sediment ER-L

-38-

and ER-tt screening values. The remedies for Operable Units Oneand Two (described in detail in the ROD-OU1. Reeves Site. October1992 and the RQD-OU2. Reeves Site. September 1993) are expectedto significantly reduce or eliminate the potential for the ReevesSoutheaster site to act as sources of contamination to the NorthWetland and unnamed creek. However, If monitoring indicates apotential threat to human health or the environment, EPA, inconsultation with the State of Florida, will reconsider theprotectiveness of this alternative and the need for additionalremedial actions.

The estimated cost for the remedy is $39,860. This SelectedRemedy is protective of human health and the environment.

9.2 Ma-lor Components of the Remedy

The No Action/Monitoring remedy consists of ecologicalassessments of the wetlands for a period of at least 8 years, tobe performed on no less that a semiannaual basis for the first 5years. The 8 year time period was selected to parallel theapproximately eight year time period that the OU2 naturalattenuation remedy is anticipated to take. If the OU2groundwater remedy takes longer than eight years, then themonitoring of the North Wetland and unnamed creek will beextended to match the monitor period for the OU2 remedy.Depending on the final selection of the engineering measures thatwill be undertaken to prevent infiltration of the surficialaquifer into the unnamed creek, the installation of surficialaquifer monitor wells immediately upgradient of the unnamedcreek, for the purpose of monitoring the discharge of thesurficial aquifer into the surface water in the unnamed, may berequired. Every effort shall be made to time the monitoringschedule such that one or two assessments occur before workbegins on the Operable Units One and Two remedies. The remainingassessments shall occur once the Operable Unit One and Tworemedies have been implemented. Each assessment shall includethe following:

a. General vegetation surveys to assess the composition andhealth of the plant communities and collection of samples toassess relative abundance and diversity of aquaticvertebrates and invertebrates.

b. Stapling and analysis of wetland surface water,sediMSKt, and biota. At a minimum, assays shall beconducted for the COCa identified in the FS and Section 6 ofthis ROD. Toxicity and Bioaccumulation analysis shall beconducted at least once each year of sampling (at a minimum,8 rounds in all).

c. Field measurement of hardness, Ph, temperature,dissolved oxygen and conductivity at each sampling station.

-39-

d. Monitoring selected siirficial'aquifer Wells7for tHe-safieparameters as in part b and c of this section.

The wetland remedial action will be considered complete when thefollowing conditions are met:

a) (1) engineering measures taken to prevent discharge ofgroundwater to the unnamed creek have proven to beeffective; or

(2) monitoring wells immediately upgradient of theunnamed creek demonstrate that groundwater dischargingto the surface water in the unnamed creek does notexceed F.A.C. 17-302 surface water standards for site-related contamination;

b) Operable Unit Two groundwater cleanup goals identifiedin the OU2 ROD (or any subsequent modification of thosecleanup goals) have been met; and

c) a review of post-ROD monitoring data confirms theeffectiveness of the selected remedy in providingadequate protection of human health and theenvironment.

9.3 Compliance with ARARs

The Florida Administrative Code Chapter 17-302 MaximumContaminant Levels (MCLs) for class III surface water bodies areconsidered to be ARARs for the site wetlands. NOAA ER-M/ER-Lvalues are not ARARs for this site, but will serve as guidelinesto assess overall conditions in the wetlands. The Floridasurface water standards and the NOAA ER-Ls may not be initiallymet by the selected remedy. However, these values are expectedto be achieved over a short period of time once the source andgroundwater remedies are implemented. Once the Reeves source andgroundwater remedial actions are implemented, the potential forcontaminant transport from the Reeves Southeastern facilitieswill be significantly reduced.

10.0 DOCUMENTATION OF SIGNIFICANT CHANGES

In the North Wetland FS, F.A.C. 17-302 was listed as a TBC ratherthan as aa-JURAR. In listing it as a TBC, EPA was narrowlyfocusing oil" its application to surface water runoff from the roadand other non-site sources. F.A.C. 17-302 is an ARAR in regardto hazardous substances discharges into the surface water fromthe site. The ARARs table in the ROD has been modified toreflect this change.

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RECORD OF DECISIONOPERABLE UNIT THREE

APPENDIX ARESPONSIVENESS SUMMARY

Reeves Southeastern Superfund SiteHillaborough County, Florida

v RESPONSIVENESS SUMMARY •.... .,REEVES SOUTHEASTERN SUPERFUND SITE

HILLSBOROUGH COUNTY, FLORIDA

I. Overview

The United States Environmental Protection Agency (EPA) held apublic comment period from May 2, 1994 to June 1, 1994 forinterested parties to comment on EPA's Proposed Plan for OperableUnit (OU) Three addressing the North Wetland and unnamed creek atthe Reeves Superfund Site. The comment period was originally setto end on May 31, but because the newspaper ran the notice a daylate, on May 3, the comment period was extended to June 1.During this comment period, the EPA held a public meeting at theBrandon Campus of the Hillsborough Community College on May 11,1994. At this time, EPA representatives presented both theresults of the studies undertaken at the site and EPA's preferredalternative for addressing the surface water and sedimentcontamination in the North Wetland and unnamed creek. EPA alsoinformed the audience about the one day extension of the publiccomment period.

A summary of EPA's response to comments received during thepublic comment period, known as the responsiveness summary, is •required under Section 117 of CERCLA. EPA has considered all ofthe comments summarized in this responsiveness summary indetermining the final selected remedy presented in the Record ofDecision for OU Three.

This responsiveness summary consists of the following sections!

I. Overview; This section provides an overview of thecontents of the responsiveness summary.

II. Background of CoTmnunitv Involvement an Concerns i Thissection provides a brief history of community interestand concerns regarding the Peak Oil /Bay Drums site.

Ill . Sniwarv of MB "lor Questions and Consents Received fromthe General Public During the Public Comn̂ nt Period andEPA 'B Responses i This section presents both oral andwritten comments submitted by the public and interestedgovernment agencies during the public meeting andfBblic comment period, and provides the responses toti|Me comments.

section presents comments submitted by the PRP, theReeves Southeastern Corporation, and EPA's reply tothose comments. These comments were contained in theJune 1, 1994 letter from Gayle Carlson, Esq., (Reeves'attorney) to Martha Berry, RPM/EPA. The PRP's comments

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are subdivided: in£q, threte- sections-: . .Comments on the. Proposed Plan; the Feasibility Study; and the ~Administrative Record.

II. Background of Community Involvement and Concerns

In accordance with Sections 113 and 117 of CERCLA, EPA hasconducted community relations activities at the Reeves site toensure that the public remains informed concerning progress atthe site. EPA periodically issued press releases to keep thepublic informed. There was moderate local press coverage ofEPA's activities, and EPA held meetings with county and stateofficials to advise them of the progress at the site.

A community relations plan (CRP) was developed in 1988 andrevised in 1989 to establish EPA's plan for communityparticipation during remedial activities. Following completionof the Wetlands Impact Study and Feasibility Study (WIS/FS), aProposed Plan fact sheet was mailed to local residents and publicofficials in May 1994. The fact sheet detailed EPA's preferredalternative for addressing the contamination in the North Wetlandand unnamed creek. Additionally, the Administrative Record forthe site, which contains site related documents including the WISand FS reports and the Proposed Plan, .was made available forpublic review at the information repository in the Brandon PublicLibrary. A notice of the availability of the AdministrativeRecord for the Reeves site was published in the Tampa Tribune onMay 3, 1994.

Finally, EPA held a public meeting in Brandon, Florida on May 11,1994 at the College to discuss the remedial alternatives underconsideration and to answer any questions concerning the ProposedPlans for the North, Central and South Wetlands at the Bay Drums,Peak Oil and Reeves Superfund Sites. Although attendance wasfairly low,.a few concerns were raised during this meeting.Questions were raised concerning all three wetlands sites; thisResponsiveness Summary only addresses comments directed towardsall three sites in general or the North Wetland in particular.Comments that apply specifically to the Central and SouthWetlands and proposed remedies are addressed in theResponsiveness Summaries for the ROD for those wetlands. EPA'sresponses to these concerns from the meeting and from writtencomments that were submitted to the Agency are summarized inSection XXX. The Reeves Southeastern Corporation also submitteda number of questions in writing. Because Reeves is the PRP, itscomments are addressed separately in Section IV. A transcript ofthis public meeting, was prepared by a certified notary public,and this document is a part of the Administrative Record uponwhich the remedy selected in the OU Three Record of Decision isbased.

Following the issuance of the final Record of Decision for OU

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Three, EPA will continue to Keep"tlie community informed about* *̂progress at the site through fact sheets and informal informationmeetings. Additionally, design and construction documentspertaining to the implementation of OU Three will be. placed inthe information repository at the Brandon Public Library.

Ill. Smwary of Major Questions and Comments Received from theGeneral Public During the Public Comment Period and EPA'aResponses

1. Comment: In the Proposed Plan, the following statements aremade concerning the results of the WIS:

a. The sediment of each wetland area studiedwere at least chronically toxic to daphnia.

b. The water and sediment of the unnamed creekat the northeast corner of the Reeves SEG facilitywere toxic to almost all organisms tested.

c. The sediments of the Cypress Pond were highlytoxic to fish, daphnids, algea, and bacteria.

How would the preferred alternative, NoAction/Monitoring, satisfactorily address theseissues?

Response: The responses to these issues are addressed in theorder they were asked:

*

a. Of the five, wetlands studied, two, theCypress Swamp and the Spray Field Wetland, werestudied to provide "background" data for the WIS.CERCLA only authorizes EPA to demand cleanup ofproblems caused by the Superfund site. Since thetoxicity to the daphnia also resulted from thesediments in the two background wetlands, EPAconcluded that this was not a problem that couldbe attributed to contamination from the site.

b. The WIS found that the water and sedimentfrom this area was indeed highly toxic. However,visual observation since the completion of the WIS

*'*' by several people familiar with how the unnamedcreek historically looked indicated that theunnamed creek had been dredged and straightenedout by an unknown entity since the WIS samplingevent. Sediment sampling conducted by Reeves in1993 confirmed that the levels of COCs in thesediment were dramatically lower than the levelsfound during the WIS. It is EPA's conclusion thatthe current levels of COCs in the sediment would

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not cause significantly more toxicity to aquaticorganisms that would be caused by sediment fromthe background wetlands. To assure that this isthe case, EPA is proposing to require an extensivemonitor plan that would require chemicalcharacterization, bioaccumulation andtoxicological analyses testing over a period ofyears. If the monitoring required under the planshows that there is extensive toxicity posed bythe current levels of COCs, then EPA will use thatinformation to reassess the appropriateness of theremedy.

c. EPA is not authorized under CERCLA to addressthe Cypress Swamp as a part of this projectbecause the Cypress Swamp is not a part of, oraffected by, the Reeves site. It was used as abackground wetland for the WIS.

2. Comment: In the Proposed Plan, EPA states thatimplementation of the preferred alternative wouldleave levels of two metals slightly above the ER-Ls. After reviewing the data in Table 1 of theProposed Plan, it appears that the ER-Ls areexceeded in the sediments for each of the sevenmetals represented. Chromium was found in levelsup to four times the ER-L level, lead up toeighty-eight times, mercury up to 1.6 times,nickel up to 2.4 times and, finally, zinc atlevels up to 93 times. Please explain thisdiscrepancy.

Response: In making this statement in the Proposed Plan, EPAwas referring to the 1993 data taken from samplepoints A, B and 10. Sample points 4 and 1 areupstream from the North Wetland and the levelsfound in these samples are most likely the resultof stormwater runoff from the road. Informationfound in Appendix A of the TS states that metals,including lead and zinc, are a significantcomponent of road runoff. Sample points A, B and10, which are all downstream from sample points 4and 1, are the sample points affected by surfacewater runoff from the SE6 facility. Based on themost recent sampling from these three samplingpoints, implementation of the preferredalternative would leave levels of two metalsslightly above the ER-Ls.

.3. Comment: Are NCAA's ER-Ls for inorganics applicable to thesediments in the wetlands, the unnamed creek andthe Cypress Pond? If not, please state what

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4.

specific criteria are to be used in assessingtoxicological risk of the contaminants to variousorganisms.

Responses Screening Guidelines for Inorganics were developedand are used by the National Oceanographic andAtmospheric Administration (NOAA). The ER-Llevels are the lowest screening levels used byNOAA for purposes of evaluating the effect ofsediments in wetland areas. These ER-L levels arethe most conservative of NOAA's screening levelsfor sediments and do not necessarily indicate thatsediment should be remediated to these levels.Other screening concentrations established by NOAAand used by the EPA Region IV in the WIS are theEffects Range—Median (ER-M) and the OverallEffects Threshold ("Threshold") levels. EPA doesnot have any promulgated standards for sediment,nor does EPA have a standard methodology forselecting acceptable sediment levels on a sitespecific basis.

Comment: In the NWFS, it was stated that the contaminatedsediments in the unnamed creek had been removed byan unnamed entity prior to the 1993 samplingevent. Does EPA know who this entity is or wherethis entity took the material?

Response: EPA is not aware of who this entity is or where ittook the material.

5. Comment:

Response:

v

The Florida Games and Florida Fresh WaterCommission have a list of animals, specificallybirds, that are not on the federal endangeredspecies list. When considering the potentialeffects on endangered species, does EPA look atlists of animals designated by state agencies ordoes EPA just use species that are listed by theU.S. Fish & Wildlife Service?

The concern behind this question seemed to be thatEPA did not consider State concerns when analyzingpotential effects on endangered species. However,CERCLA/SARA mandates that both the federal and thestate government designate agencies to function asNatural Resource Trustees (NRTs). One of themajor mandates of the NRTs is to determinepotential adverse effects on natural resources,which include wildlife and plantlife, as well asthreatened and endangered species. Formerly inthe State of Florida, there were two agenciesdesignated as NRTs: the Department of

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Environmental Regulation; and the Department ofNatural Resources. Recently, these two agencieswere merged into one, the Florida Department ofEnvironmental Protection (FDEP). Both the federaland the state NRTs had input into the entirewetlands investigation process and have concurredthat the preferred alternative in the ProposedPlan will be protective of both human health andthe environment.

IV. Summary of PRP Comments and EPA's Responses

The Proposed Plan

1. Comment: The "Description and History" section includes adetailed description of Reeves SoutheasternCorporation ("Reeves") and the Superfund studiesconducted at Reeves' Southeastern Galvanizing("SE6") and Southeastern Wire ("SEW") properties.This section incorrectly gives the impression thatthe North Wetiand is part of the SoutheasternGalvanizing site.

It is important to note that the North Wetland is*not and has never been a part of the propertyowned by Reeves. It also is important to notethat only the small portion of the drainage swale(referred to in the Proposed Plan as the "unnamedcreek") that crosses the northwest corner ofReeves' SEG property is owned by Reeves. Theremainder of the.drainage swale is owned by athird party. Additionally, Reeves has neverconducted any activities in or around the NorthWetland.

Based on the information in the Area-WideHydrologic Remedial Investigation Report ("Area-Wide RI") and the North Wetland Feasibility Study("NWFS"), impacts to the North Wetland would haveresulted from sources other than Reeves. As theNWFS notes, the Area-Wide RI states that thestormwater runoff at the SEG property flows northand west into the drainage swale, not to the NorthWetland. In addition, the NWFS (page 2-3) notes

'"" that the levels of inorganics in the North Wetlandare comparable to those in the upgradient drainageditch that flows into the North Wetland via theculvert under State Road 574.

The Proposed Plan and the Record of Decision to beissued subsequently should include discussions ofthe many other sources of potential impacts to the

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North Wetland and the drainage swale, which arediscussed in the NHFS. These other sourcesinclude, but are not limited to, air emissionsfrom the Hillsborough County Resource RecoveryPlant and stormwater runoff from ditches alongState Road 574, from a culvert under State Road574 (draining a 49-acre watershed south of thehighway, including the Peak Oil and Bay DrumsSuperfund Sites and the railroad tracks), and fromwest of the North Wetland (including drainagethrough a large area formerly an automobilesalvage yard and still containing remnants ofJunked vehicles and debris), and stormwater fromditches, storm sewer outfalls and sheetflow runoff

. from roadways, parking lots and other areas in anindustrial and office park.

In spite of statements to the contrary in certainEPA documents, these culverts remain open, and infact there are other culverts from the Peak Oiland Bay Drums Sites to the ditches along therailroad tracks that are still open (see theletter from John Goolsby contained in the Reeves'submittal by Gayle B. Carlson to David Abbottdated October 5, 1993, which is part of theAdministrative Record). We want to emphasize thecontinuing influences from these sites as well asthe likelihood that contaminants will be releasedfrom the Peak Oil and Bay Drums Sites to the NorthWetland during the remedial actions scheduled totake place at those sites.

Response: EPA does not dispute the significant points ofthis comment, therefore, EPA has no response.However, EPA emphasizes that the implementation ofthe remedies for the Peak Oil/Bay Drums sites, ifproperly done, should not result in the release ofcontamination from those sites.

2. Comment: Pages 2 and 4 of the Proposed Plan discuss onlyOperable Units One and Two that will be conductedby Reeves. This discussion should also includethe operable units for the Peak Oil and Bay Drums

3. Comment s

Response s

4. Comment:

Responses

the selected .operable unit remediea for all threesites in its decision documents. To provide thehistories for all three sites would be verycumbersome and would only grow more so as thevarious RD/RAs are implemented. EPA does agreewith the point that the source control RD/RAs atthe Peak Oil/Bay Drums sites may have ah impact onthe North Wetland and unnamed creek if the RD/RAsare not properly implemented.

The first paragraph on page 4, the phrase "withina one mile radius of the site" should be omittedto reflect the EPA's revised scope of work for theReeves OU2.

This revision will be made as appropriate infuture documents.

Page 5 of the Proposed Plan states as followss"Based on data developed in the Wetlands ImpactStudy ("WIS"), it has been determined that themain contributor to any potential problem in theNorth Wetlands is the Reeves SEG facility." Thisconclusion is not drawn in the WIS, and the WISactually states that surface water drainage fromthe Peak Oil and Bay Drums sites flows to theNorth Wetiand via a drainage ditch and a culvertunder SR 574 (see pages 2-3 and 5-1 of the WIS).With respect to the SEG property, the WIS states,in much less conclusive terms than reported onpage 5 of the Proposed Plan, that surface runofffrom the SEG property "appears probable" (see page5-1 of the WIS). Further, contrary to thisinconclusive intimation in the WIS, we show belowin the Feasibility Study comments that the SEGfacility could not have contributed to any impactsin the North Wetland. It is clear frominformation reported in the Area-Wide RI (seepages 4-76 through 4-78), the WIS (see pages 2-3and 5-1), and the North Wetland Feasibility Study(see, e.g., pages 2-7, 3-6, and 3-20) that thereare many sources that may have affected and may beaffecting the North Wetland.

There are many potential sources of contaminationof the North Wetland, of which the SEG facility isprobably one. The topography of the southwestcorner of the SEG facility slopes towards theNorth Wetland; therefore any contaminated soils inthat area could have been carried by stormwaterrunoff into the wetland. Regardless of the manysources of contamination for the North wetland,

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'there is no question that the SEG facility is themain contributor of contamination in the unnamedcreek and this is the area .of offsitecontamination that was of most concern to EPA andto the natural resource trustees.

5. Comment: At the top of the right-hand column on page 8 ofthe Proposed Plan, there is a reference to "bycontaminated groundwater in the Northern SurficialAquifer." It appears that the above phrase shouldbe deleted and replaced by "by the North Wetlandand the drainage swale."

Response: This error will be corrected in future documents.

6. Comment: Reeves agrees with the EPA's selection ofAlternative 1 B for the North Wetland OU3. Reevesnotes, however, that the cost estimate included inthe Proposed Plan may be significantlyunderstated, depending on the types of testingrequired (see Comment 5 below in the comments onthe North Wetland Feasibility Study).

Response: EPA concurs that the cost estimate in the ProposedPlan does not reflect the cost of the types oftesting requested by the natural resourcetrustees. However, the cost estimate is accuratein its relationship to the other cost estimatesand, thus, fulfills its requirement to provide anaccurate comparison of the relative costs of thealternatives.

The Feasibility Study

1. Comment: With respect to Sections 1.2.1 (Site Description)and 1.2.2 (Site History) of the NWFS, we hereincorporate Comment 1 from the Proposed Plandiscussion above.

Response: Please refer to EPA's response to Comment #1 onthe Proposed Plan.

2. Commenti With respect to Section 1.2.2 of the NWFS, we alsohere incorporate Comment 2 from the Proposed Plandiscussion above.

Response: Please refer to EPA's response to Comment f2 onthe Proposed Plan.

3. Comment: In the last paragraph of Section 1.2.2.1 (page 1-6), the phrase "within a one mile radius of thesite" should be deleted to reflect the EPA's

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revised scope of work for the Reeves OU2.

Responses This change will be reflected in future documents.

Commentt Reeves disagrees with the statement in Section2.2.1.1 (page 2-8) that "for the reasons that aremore fully explained in another Chapter, it hasbeen determined that the main contributor to anypotential problem in the North Wetlands is theReeves SEG facility." There simply is no otherchapter in the NWFS that discusses any basis forthe foregoing conclusion. To the contrary, asstated in Comments 1 and 4 from the Proposed Plandiscussion above, impacts to the North Wetlandhave resulted from sources other than Reeves. Asthe NWFS itself notes throughout, all thetopographical information collected during theArea-Wide RI shows that the stormwater runoff atthe SEG property flows north and west into thedrainage swale, not to the North Wetiand. TheNWFS includes several discussions of the manyother so