Superfund Record of Decision Nc State University Lot 86 Farm Unit #1 Raleigh NC


                                    EPA/ROD/R04-96/277
                                    1996
EPA Superfund
     Record of Decision:
     NORTH CAROLINA STATE UNIVERSITY (LOT 86,
     FARM UNIT #1)
     EPA ID: NCD980557656
     OU01
     RALEIGH, NC
     09/30/1996

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                         RECORD OF DECISION
                        NC STATE UNIVERSITY
                          LOT 86 SUPERFUND
                               SITE

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                         TABIiE OF CONTENTS

DECISION SUMMARY	1-1
     I.   SITE NAME, LOCATION AND DESCRIPTION	1-1
          A. Introduction	1-1
          B. Site Description	1-1
          C. Demography and Land Use	1-1
          D. Geology	1-1
          E. Hydrogeology	1-2
          F. Climate/Meteorology	1-2

     II.  SITE HISTORY AND ENFORCEMENT ACTIVITIES	2-1
          A. Site History	2-1
          B. Summary of Previous Investigations  	 2-1
          C. Enforcement Activities	2-1

     III. HIGHLIGHTS OF COMMUNITY PARTICIPATION  	 3-1

     IV.  SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE
          STRATEGY	4-1

     V.   SUMMARY OF SITE CHARACTERISTICS	5-1
          A. Groundwater Investigation  	 5-1
          B. Soil Investigation	5-2
          C. Surface Soil Investigation	5-2
          D. Subsurface Soil Results	5-3

     VI.  SUMMARY OF SITE RISKS	6-1
          A. Contaminants of Cancer	6-1
          B. Exposure Assessment	6-1
          C. Toxicity Assessment	6-1
          D. Risk Characterization	6-2
          E. Environmental Assessment	6-5
          F. Conclusions	6-5

     VII. APPLICABLE OR RELEVANT AND APPROPRIATE
          REQUIREMENTS  (ARARs)	 7-1
          A. Action-Specific ARARs	7-1
          B. Location-Specific ARARs  	 7-1
          C. Chemical-Specific ARARs	7-2

     VIII. REMEDIAL ACTION OBJECTIVES  	 8-1
          A. Groundwater	8-1
          B. Extent of Contamination Above Remediation
             Levels	8-2

     IX.  DESCRIPTION OF ALTERNATIVES	9-1
          A. Remedial Alternatives to Address Groundwater
             Contamination  	 9-1

     X.   SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES .  .10-1
          A. Comparative Analysis of Soil Alternatives   . .  .10-4
          B. Comparative of Groundwater Alternatives  .  . .  .10-5

     XI.  THE SELECTED REMEDY	11-1
          A. Soil Remediation	11-1
          B. Groundwater Remediation	11-1
          C. Extraction and Performance Standards	11-2

APPENDIX I
     RESPONSIVENESS SUMMARY

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                    DECLARATION FOR THE RECORD OF DECISION

SITE NAME AND LOCATION

NC STATE UNIVERSITY LOT 86 SITE,
RALEIGH, WAKE COUNTY, NORTH CAROLINA

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial action for the NC State University Lot 86
Site in Raleigh, Wake County, North Carolina, chosen in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980  (CERCLA),  as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA) and, to the extent practicable, the
National Contingency Plan  (NCP).  This decision is based on the administrative record file for
this Site.

The State of North Carolina concurs with the selected remedy.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from this Site, if not addressed by
implementing the response action selected in this Record of Decision, may present an imminent
and substantial endangerment to public health, welfare, or the environment.

DESCRIPTION OF THE SELECTED REMEDY

This remedy addresses the principle threat of contaminated groundwater emanating from beneath
the Site.

The major components of the selected remedy include:

       SOIL

       The soil remedy is In-situ Mixing and Encapsulation. The soils will be mixed intially
       within the bore hole and the VOCs that are released as a result of the mixing will be
       captured via a specially designed bore hole shroud,  and treated.   The treatment may
       include but not be limited to liguid vapor separation, in-line prefiltration for dust and
       particulate removal, followed by parallel activated carbon filter banks. The remaining
       contaminants will be solidified in-situ
       using various pozzolan-portland cement based formulations delivered to and dispersed
       within the soil column as a grout.

       GROUNDWATER

       Extraction of groundwater at the Site that is contaminated above Remediation Goals as
       provided in Table 11-1 of this document.

       Onsite treatment of extracted groundwater via air stripping,  and carbon adsorption;
       Discharge of treated groundwater to surface water or local publicly owned treatment
       works(POTW) .

STATUTORY DETERMINATIONS

The selected remedy is protective of human health and the environment, complies with federal and
state reguirements that are legally applicable or relevant and appropriate to the remedial
action, and is cost-effective.  This remedy utilizes permanent solutions and alternative
treatment technology to the maximum extent practicable, and satisfies the statutory preference
for remedies that employ treatment that reduces toxicity, mobility,  or volume as a principal
element.  Since this remedy may result in hazardous substances remaining onsite above health
based levels, a review will be conducted within five years after commencement of remedial action
to ensure that the remedy continues to provide adeguate protection of human health and the
environment.

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DECISION SUMMARY

I. SITE NAME, LOCATION AND DESCRIPTION

A. Introduction

The North Carolina State University Lot 86 Site (herinafter referred to as the "Lot 86 Site" or
the "Site") is a 1.5-acre site located on the west side of Raleigh, North Carolina (Figure 1-1).
The NCSU Lot 86 site served as a disposal site for chemical and low level radioactive wastes
(LLRW) generated in the educational and research laboratories at NCSU from 1969 until 1980. The
wastes were disposed in subsurface trenches and covered with native soils. The waste deposited
in the trenches is responsible for the groundwater and soil contamination present on Site.

B. Site Description

The NCSU Lot 86 site is northeast of Carter-Finley Stadium and immediately south of the Wade
Avenue Extension right-of-way and is surrounded by state-owned property (figure 1-2). The site
is bound on the west by the stadium parking area and surround by trees on the three remaining
sides.

The source of the contamination is attributed to solvents, pesticides, heavy metal, acids, and
low-level radioactive waste buried in trenches which are 10' deep varying in lengths from 50 to
150 feet, totaling 2000 linear feet.

C. Demography and Land Use

The 1.5 acre site is located on and surrounded by state-owned property. The site is secured
with a chain-link fence with a padlock on the gate. The site is covered with grass and weeds
and no structures are present. A large grass-covered open area, adjacent to the west of the
site and north of Carter-Finley Stadium, is used for parking during stadium events. The road
leading into this area from Old Trinity Road is used as a jogging path by NCSU students, faculty
and area residents. Trees along the fence north of the site screen the view from Wade Avenue.
A pine forest borders the site to the east and south. The nearest water supply well is located
approximately 2,000 feet southeast of the site at the Medlin residence.

D. Geology

The region's crystalline bedrock weathers chemically and physically in-place to form a
unconsolidated mantle of soils and partially weathered rock termed the regolith. The regolith
consist of three distinct zones: residual soils at the surface, saprolite, and weathered rock.
The surface soils of the study area included low compressibility silts, high compressibility
silts, micaceous silts, and low to high compressibility clays. The saprolite is somewhat porous
and granular due to the disintegration of feldspar crystals and solution removal of some
internal rock mass and volume solids. Saprolite retains many aspects of the parent bedrock
(banding, foliation, and structural features such as fractures) and its grain size ranges from
clay to boulders. Silts and sands are common components, micas may be present in great guantity.
The saprolite is directly underlain by a weathered rock zone. The weathered rock zone is of
variable thickness and physical character; there is no sharp delineation between the regolith
and the bedrock. The bedrock surface is uneven; the rock may be fractured or fissured for
several hundred feet within its unaltered mass.

E. Hydrogeology

Groundwater occurs in the silty clay/granular soils (residual and saprolite) and in the
underlying crystalline bedrock under generally water table (unconfined) conditions. The
unconsolidated soils aguifer is chiefly replenished by the infiltration of precipitation where
the unit is exposed. The shallow unconsolidated residual soil/saprolite water-bearing unit exist
at depths ranging from 20 ft to 40 ft below land surface, and flows west northwest toward Wade
Avenue.

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F.  Climate/Meteorology

The average annual precipitation is 46 inches, with July and August being the wettest months.
Average monthly temperatures range from a low of 40.2 degrees Fahrenheit(5F) in January to a
high or 78.85F in July.  The warm summer temperatures combined with heavier precipitation in
these months serve to maintain a typically humid environment.

II.  Site History

The NCSU Lot 86 Site was used as a hazardous chemical and low level radioactive waste site
beginning in 1969.  The waste was generated in the University's educational and research
laboratories.  The site was divided into two separate areas as shown on Figures 2-1; the western
area received the hazardous chemical waste, and the eastern area received low level radioactive
waste  (LLRW).  Burial of waste was discontinued in November 1980, to comply with regulations
promulgated under the Resource Conversation and Recovery Act  (RCRA).

The chemical wastes were placed in trenches and back filled with approximately 2 feet of native
soils.  There are 22 trenches approximately 10 feet deep and varied from 50 to 150 feet in
length.  Types or chemical buried at the site include solvents, pesticides, inorganics, acids,
and bases. NCSU reported that it had disposed of approximately 11,000 cubic yards of chemical
waste at the site.  Quantities reported included lightly contaminated soils and water as well as
actual waste materials.

Radiological wastes were buried in trenches approximately 6 feet deep and 50 to 120 feet long.
Nine trenches were reportedly excavated and used for LLRW disposal.  The depth of wasted in the
bottom of the trenches was reported to be 2 feet with 4 feet of native soil cover material.
Records concerning waste disposal in this area are maintained by the NCSU Radiation Protection
office in complete conformance with applicable AEC/NRC regulations.  These records indicate
that the wastes were properly disposed at the site.  Most of the LLRW waste is in solid from,
primarily animal carcasses, which range in size form rats to whole sheep.  Radionuclides
present in the waste include tritium, carbon-14, iron-59, phosphorus-32.

The site was placed on the National Priority List  (NPL) in October 1984,  based on results from
an inspection completed earlier in June.



III.  HIGHLIGHTS OF COMMUNITY PARTICIPATION

Pursuant to CERCLA Section 113(K)(2)(B)(i-v) and Section 117, the RI/FS Report and the Proposed
Plan for the NC State Lot 86 Site were released to the public for comment on June 26, 1996.
These documents were made available to the public administrative record located in the
information repository maintained at the EPA Docket Room in Region IV and at the Cameron Village
Regional Public Library, 1930 Clark Avenue, and D. H. Hill library, North Carolina State
University, Raleigh, North Carolina.

The notice of availability for these documents was published in the Raleigh News & Observer on
June 26, 1996.  A public comment period on the documents was held from June 26, 1996 to July 26,
1996.  A copy of the notice was mailed to the individuals on the mailing list.  In addition, a
public meeting was held on July 9,  1996.  At this meeting, representatives from EPA answered
guestions about problems at the Site and the remedial alternatives under consideration.

Other community relations activities included;

       •      Community Relations plan finalized in May of 1993 and a copy was placed in
              information repository.

       •      Issuance of a Fact Sheet on the RI/FS process in August 1993.

       •      Public meeting on September 7,  1993,  to discuss the superfund process.   The meeting
              was announced by a display ad that appeared in the newspaper on August 31,  1993.

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• Issuance of a Fact Sheet on the Proposed Plan for the Lot 86 Site on June 26, 1996,
in conjunction with the announcement that was displayed in the Raleigh News &
Observer. The meeting was held on July 9, 1996.

IV. SCOPE AND ROIiE OF RESPONSE ACTION WITHIN SITE STRATEGY

The Lot 86 Site will not be subdivided into phases or operable units. The remedial action
described in this documents will address all medias of concern, including any and all principal
threats.

Medias of concern include the contaminants contained in the on site trenches and the resulting
groundwater plume migrating to the west, northwest. This final remedy is intended to address
the entire Site with regard to the principal threats to human health and the environment posed
by the site as indicated in the risk assessment. The findings of the risk assessment are
included in the RI Report and are summarized in Section VI of this document.

V. SUMMARY OF SITE CHARACTERISTICS

The Remedial Investigation (RI) at the N.C. State Lot 86 Site included the characterization of
routes of contaminant migration which included the soil and groundwater. The Site did not
include any surface features.

A. Groundwater Investigation

The goal of the groundwater investigation was to verify the reliability of groundwater samples
previously taken during previous investigations as well as supplement that sample data to fully
assess the extent and level of contamination present in the aguifer system.

To accomplish that goal, eight new stainless steel monitoring wells were constructed during the
investigation (Figure 5-1) to supplement the existing wells installed by the University during
previous studies. Samples were collected from the 8 new stainless steel wells, 11 existing
wells (4 stainless steel, 7 PVC), and one domestic well (Medlin residence).

Groundwater organic results indicated that VOCs were the most prevalent group with low levels of
semivolatile organics and pesticides detected. VOC concentrations are notably higher in the
shallow aguifer than in the bedrock aguifer, with the highest concentration near the landfill.
Chloroform, methylene chloride, benzene, carbon tetrachloride, and trichloroethane (TCE) were
identified as compounds detected most freguently and at the highest concentrations. VOCs were
not present in background and upgradient wells. The highest VOC concentrations in groundwater
occurred in wells MW-37, MW-36s, MW-5A, and MW-1B in the top 5 to 10 feet of the saturated zone,
just off the west and northwest portions of the landfill, nearest the trenches. Low levels of
VOCs were detected in some of the deep wells. Concentrations decrease significantly with
depth and as you move away from the landfill to the north and west.

All of the semivolatile and pesticide detection in groundwater were low level concentrations.
Within the semivolatile organic group, three parameters were detected at three different wells.
Bis(2-ethlyhexyl)phthalate was detected at 41 milligrams per liter(mg/1) in the background
well, MW-34D. Isophorone was detected at 570 mg/1 in MW-37, and napthalene was detected at 30
mg/1 in MW-36S. Pesticides (chlordane, dieldrin, and lindane) were detected in shallow wells
MW-34S, MW-35S, and MW-37, respectively.

Arsenic, barium, chromium, copper, lead, manganese, and zinc were identified in downgradient
wells at concentrations above those present in the upgradient wells. Of those only Arsenic, was
detected at 110 Ig/1 in MW-36D, however arsenic was not found in MW-36S. Lead was detected at
concentrations of 21 Ig/1 and 31 Ig/1 at MW-36S and MW-37 respectively. Concentration of
manganese above MCL was detected in all of the shallow wells including the background well.
Concentrations ranged from 370 Ig/1 at MW-34S to 20,000 Ig/1 at MW-36S. Maganese was also found
at concentrations above MCL in the bedrock aguifer at several locations.

All groundwater samples were analyzed for carbon-14 and tritium. Carbon 14 was detected in one
well just above the detection limit of 500 pCi/1 at 522 pCi/1 in MW-38. Tritium was detected at

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three wells at concentrations ranging from 711 pCi/1 to 6000 pCi/1, which are well below the MCL
of 20,000 pCi/1.

B. Soil Investigation

The purpose of the shallow soil samples was to determine if contaminants had migrated
horizontally from the trenches and if surficial contamination was evident. Surface soil samples
were collected from 0' to I'-O" intervals. Shallow soil samples were collected from shallow
soil borings at intervals of 4'0" to 6'-0" and 10'-0" to 12'-0" below existing ground surface.
Surface and shallow soil samples were also taken from monitoring well borings at 2 foot
intervals above the water table and at 5 foot intervals below the level at which groundwater was
encountered. At MW-34S, MW-35D, and MW-36S two to five representative samples were collected.
The 93 samples collected were subjected to gross volatile hydrocarbon and radiation field
screening, as well as selected VOC screening using the GC. Based on the screening results,
selected samples were shipped to th laboratory for TAL/TCL confirmational analysis. (See Figure
5-2 for depiction of sample locations.)

C. Surface Soil Results

In general, all detected volatile organics in surface soils were at low concentrations. The
most freguently detected VOC was acetone (six detects), which included two detection at a
background location. Other VOC detections included 1,2-dichloropropane, 1,1-dichloroethane,
chloroform, methlyene chloride, tetrachloroethene, toluene, and trichloroethene.

The most frequent detection within the semivolatile group was bis(2-ethlyhexyl)phthalate, with
one of four detections occurring at a background location. All detected semivolatile
concentrations were less than 5 mg/kg and average less than 1 mg/kg. All detection of
pesticides were less than 8 Ig/kg. Aroclor 1260 was detected at SB-25-01 at 40.3 Ig/kg.

Concentrations of inorganic parameters in surface soil samples from the vicinity of the landfill
are similar to those in background samples and those typical of soils in this part of North
Carolina. Most of the highest metals concentrations were observed in the background samples.

Selected surface soil samples were analyzed for carbon-14 and tritium. There were no detectable
levels of tritium (0.2 picocuries per gram(pCi/g)) or carbon-14 (0.5pCi/g).

D. Subsurface Soil Results

Subsurface organic results indicate that semivolatiles and pesticides are not of concern in the
deeper soils. Volatile organic exhibited more of a presence in subsurface soils, primarily in
well borings closest to the disposal trenches (MW-37 and MW-38). In the saturated soils
chemicals detected were at low levels, and increased in concentration closer to the top of the
groundwater table. All of the maximum VOC concentrations and the trace concentrations of
semivolatile compounds were detected in the 35 to 37-foot depth interval in wells MW-37 and
MW-38.

In the saturated soils, the highest volatile concentrations were observed in the top of the
saturated zone. Acetone, 2-butanone, 4-methly-2-pentanone, and chloroform were the most
freguently detected chemicals, with the maximum concentrations occuring at the 40 to 42 foot
depth interval in boring MW-38. Subsurface inorganics are comparable with those in background
samples and those typical of soils in this part of North Carolina. Of the radioactive
constituents tritium was the only one detected, and those detection were very near the detection
limits.

VI. SUMMARY OF SITE RISKS

The NC State Lot 86 Site is releasing contaminants into the environment. The Baseline Risk
Assessment Report presents the results of a comprehensive risk assessment that addresses the
potential threats to public health and the environment posed by the Site under current and
future conditions, assuming that no remedial actions take place, and that no restrictions are
placed on future use of the Site. The Baseline Risk Assessment being summarized in this section

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considered the Site risks associated with the soils, groundwater and the air pathways associated
with those two medias.

The Baseline Risk Assessment Report consists of the following sections: identification of
chemicals of potential concern; toxicity assessment; human exposure assessment, risk
characterization; and environmental assessment. All sections are summarized below.

A. Contaminants of Concern

Data collected during the RI was reviewed and evaluated to determine the contaminants of concern
at the Site which are most likely to pose risks to the public health. These contaminants were
chosen for each environmental media sampled.

Once these contaminants of concern were identified, exposure concentrations in each media were
estimated. Exposure point concentrations were calculated for groundwater and surface soils
using the lesser of the 95 percent upper confidence limit concentration or the maximum detected
value as the reasonable maximum exposure (RME) point concentration. Exposure point
concentrations for groundwater are shown in Table 6-1. Exposure point concentration for the
surficial soils are presented in Table 6-2

B. Exposure Assessment

The exposure assessment evaluates and identifies complete pathways of exposure to human
population on or near the Site. Current and future exposure scenarios include potential surface
soil exposure via incidental ingestion and dermal contact; ingestion of groundwater; and
inhalation of volatiles evolved from groundwater during household water use. Further detail and
mathematical calculations can be reviewed in the Baseline Risk Assessment (BRA). Table 6-3
provides the exposure assumptions that were used in the BRA.

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                                   Table 6-1

                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
             Shallow Groundwater Exposure Point Concentrations
Groundwater Analyte
 INORGANICS
 Barium
 Chromium
 Cobalt
 Lead
 Manganese
 Nickel
 VOLATILE ORGANICS
 Acetone
 Benzene
 Bromodichloromethane
 Bromoform
 Carbon Tetrachloride
 Chlorobenzene
 Chloroform
 Dibromochloromethane
   95% UCL of
     Mean
Concentration
    (Ig/L)

    2,780
      919
    4,936
    1,440
   54,500
    5,051

   72,200
   45,300
  209,800
   22,715
   17,100
   75,967
  312,000
    4, 609
Ig/L = micrograms per liter
pCi/L = picoCuries per liter
                                       Site-Related Samples
    Maximum
Concentrations
    (Ig/L)

      950
     17.0
     88.0
     31.0
    20,000
     73.0

    15,500
    14,000
      280
      35.5
     6,400
      150
    63,000
     3.35
  Exposure
    Point
Concentrations
    (Ig/L)

     950
    17.0
    88.0
    31.0
   20,000
    73.0

   15,500
   14,000
     280
     35.5
    6,400
     150
    63,000
     3.35
                           Table 6-1 (Continued)

                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
              Shallow Groundwater Exposure Point Concentrations

                                       Site-Related Samples
Groundwater Analyte
      95% UCL of
         Mean
    Concentration
         (Ig/L)
        Maximum
    Concentrations
        (Ig/L)
       Exposure
        Point
    Concentrations
        (Ig/L)
1,1-Dichloroethene
1,2-Dichloroethene (total)
1,2-Dichloropropane
2-Hexanone
Methylene Chloride
4-Methyl-2-pentanone
1,1,2,2-Tetrachloroethane
Tetrachloroethene
Toluene
1,1,2-Trichloroethane
Trichloroethene
Vinyl Chloride
SEMI-VOLATILE/ORGANICS
Isophorone

Ig/L = micrograms per liter
pCi/L = picoCuries per liter
       27,500
        9,191
       41,800
        4,952
       64,500
       66,682
      246,676
      697,000
      455,000
       74,091
      904,000
        4,774
        2,
         21.0
         31.0
          865
         5.45
        18,000
         110
         200
        5,000
        1,500
         135
        1,250
         3.7

         570
        21.0
        31.0
         865
        5.45
       18,000
        110
        200
       5,000
       1,500
        135
       1,250
        3.7

        570

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                          Table 6-1 (Continued)

                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
             Shallow Groundwater Exposure Point Concentrations
                                       Site-Related Samples
Groundwater Analyte
             95% UCL of
                Mean
           Concentration
               (Ig/L)
PESTICIDES/PCBs
gamma-BHC
Dieldrin
RADIONUCLIDES
Tritium
                0.05
                13.4
concentrations in pCi/L)
                1,200
         Maximum
     Concentrations
         (Ig/L)

         0.016
         0.013

         6,000
Ig/L = micrograms per liter
pCi/L = picoCuries per liter
                                 Table 6-1
       Exposure
         Point
     Concentrations
        (Ig/L)

        0.016
        0.013

        1,200
                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
               Deep Groundwater Exposure Point Concentrations

                           Site-Related Samples
   Groundwater
    Analyte
       95% UCL of
          Mean
     Concentration
         (Ig/L)
   Maximum
Concentrations
   (Ig/L)
Exposure Point
Concentrations
    (Ig/L)
 INORGANICS
 Arsenic                 2,350
 Chromium                4,003
 Copper                 11,403
 Manganese               3,130
 Zinc                    8,600
 VOLATILE ORGANICS
 Acetone                   959
 Benzene                   549
 Bromodichloromethane      541
 Carbon Tetrachloride      199
 Chlorobenzene             2.8
 Chloroform                640
 1,2-Dichloroethane      2,947
 1,2-Dichloropropane       699
 Methylene Chloride        155

Ig/L = micrograms per liter
pCi/L = picoCuries per liter
                            110
                            20.0
                            48.0
                            460
                            67.0

                            190
                            7.3
                            44.0
                            39.0
                            1.0
                            510
                            2.5
                            28.0
                            59.0
                      110
                      20.0
                      48.0
                      460
                      67.0

                      190
                      7.3
                      44.0
                      39.0
                      1.0
                      510
                      2.5
                      28.0
                      59.0

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                           Table 6-1 (Continued)

                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
               Deep Groundwater Exposure Point Concentrations

                           Site-Related Samples
Groundwater
Analyte

4-Methyl-2-pentanone
1, 1, 2, 2-Tetrachloroethane
Tetrachloroethene
Toluene
Trichloroethene
95% UCL of
Mean
Concentration
(Ig/L)
3.3
101
5,546
16.8
88,159
Maximum
Concentrations
(Ig/L)

3.0
5.8
5.7
1.3
20.0
Exposure Point
Concentrations
(Ig/L)

3.0
5.8
5.7
1.3
20.0
RADIONUCLIDES (concentrations in pCi/L)
Carbon- 14
Tritium
1, 679
7,560
522
3,890
522
3,890
Ig/L = micrograms per liter
pCi/L = picoCuries per liter

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                                 Table 6-2

                    North Carolina State University Site
                 Chemicals of Potential Concern Detected in
                     Soil Exposure Point Concentrations

                                         Site-Related Samples
                         95% UCL of
 Surface Soil Analyte       Mean
                        Concentration
                            (mg/kg)
               Maximum
            Concentrations
               (mg/kg)
               Exposure Point
               Concentrations
                  (mg/kg)
INORGANICS
Chromium
Nickel
SEMI-VOLATILE ORGANICS
Bis(2-ethylhexyl)phthalate
PESTICIDES/PCBs
Aroclor 1260
alpha-Chlordane
gamma-Chlordane
P,P'-DDE
P,P'-DDT
Dieldrin
VOLATILE ORGANICS
Chloroform
1,2-Dichloroethane
1,2-Dichloropropane
Methylene Chloride
65.3
 7.2
89.0
13.0

 1.5
65.3
 7.2

1.32
0.03
0.006
0.004
0.008
0.007
0.006
0.01
0.01
0.01
0.01

0
0
0
0
0
0
0
0
0
0.04
.005
.003
.007
.006
.005
.006
.003
.013
.003
0.03
0.005
0.003
0.007
0.006
0.005
0.006
0.003
0.01
0.003
mg/kg = milligrams per kilogram

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Exposure
 Media

Groundwater
Surficial
  Soils
                    Table 6-3

       Potential Exposure Pathways/Routes

Scenario              Receptor


 Future       Resident (Child, Youth 7-16, and Adult)
 Current      Visitor (Child, Youth 7-16, and Adult)
              Recreational Person (Child, Youth 7-16, and Adult)
              Student (Adult)

 Future       Resident (Child, Youth 7-16, and Adult)
      Exposure Pathways
1.   Ingestion of drinking water
2.   Inhalation of VOCs released
    to indoor air

1.   Incidental ingestion
2.   Dermal contact
                                                                                   1.  Dermal contact
                                                                                   2.  Incidental ingestion

-------
C. Toxicity Assessment

Under current EPA guidelines, the likelihood of adverse effects occurring in humans from
carcinogens and noncarcinogens are considered separately. These are discussed below. Table 6-4
summarizes the carcinogenic and noncarcinogenic toxicity criteria for the contaminants of
concern.

Cancer slope factors (CSFs) have been developed by EPA for estimating excess lifetime cancer
risk associated with exposure to potentially carcinogenic chemicals. CSFs, which are expressed
in units of (mg/kg-day) -1, are multiplied by the estimated intake dose of a potential
carcinogen, in mg/kg-day, to provide an upperbound estimate of the excess lifetime cancer risk
associated with exposure at that intake level. The term "upperbound" reflects the conservative
estimate of the risks calculated from the slope factor. Use of this approach makes
underestimation of the actual cancer risk highly unlikely. Cancer potency factors are derived
from the results of human epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation and uncertainty factors have been applied.

Reference Doses (RfDs) have been developed by EPA for indication of the potential for adverse
health effects from exposure to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of acceptable lifetime daily exposure levels for
humans, including sensitive individuals. Estimated intake dose of chemicals from environmental
media can be compared to the RfD. RfDs are derived from human epidemiological studies or animal
studies to which uncertainty factors have been applied. These uncertainty factors help ensure
that the RfDs will not underestimate the potential for adverse noncarcinogenic effects to occur.

In the case of lead, EPA recommends the use of the Agency's Uptake Biokinetic model which
predicts blood-lead levels for children ages 0.5-7 years under various exposure scenarios and
lead concentrations.

D. Risk Characterization

The risk characterization step of the baseline risk assessment process integrates the toxicity
and exposure assessments into guantitative and gualitative expressions ofrisk. The output of
this process is a characterization of the Site-related potential noncarcinogenic and
carcinogenic health effects.

Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the hazard guotient (HQ), or the ratio of the estimated intake derived from the
contaminant concentration in a given medium to the contaminant's reference dose. By adding the
HQs for all contaminants within a medium or across all media to which a given population may be
reasonably exposed, the Hazard Index (HI) can be generated. Calculation of a HI in excess of
unity indicates the potential for adverse health effects. Indices greater than one will be
generated anytime intake for any of the chemicals of concern exceeds its Reference Dose (RfD).
However, given a sufficient number of chemicals under consideration, it is also possible to
generate a HI greater than one even if none of the individual chemical intakes exceeds their
respective RfDs.

Carcinogenic risk is expressed as a probability of developing cancer as a result of lifetime
exposure to a contaminant concentration in a given medium. Excess lifetime cancer risks are
determined by multiplying the intake level with the cancer potency factor. EPA's acceptable
target range for carcinogenic risk is one-in-ten-thousand (1E-4) to one-in-one-million (1E-6).

-------
                                  Table 6-5
             Lifetime Cancer Risk - Current and Future Scenarios
                Reasonable Maximum Exposure Concentrations
 Exposure Medium

 Surface Soil
 Groundwater - Shallow
 Groundwator - Deep
 Total
Current
Student
3x10 -8
NE
NE
3x10 -8
Current Current Recreational Future
Visitor
7x10
NE
NE
7x10
-9


-9
Person Residen'
3x10
NE
NE
3x10
-7


-7
7x10
1x10
4x10
1x10
-7
-1
-3
-1
NE = Not evaluated in this pathway

-------
Neither a cancer slope factor nor a reference dose is available for lead. Instead, blood lead
concentrations have been accepted as the best measure of exposure to lead. The EPA has
developed a biokinetic/uptake model to assess chronic and nonchronic exposure of children to
lead. The uptake/biokinetic model estimates total lead uptake resulting from diet, inhalation,
and ingestion of soil/dust, water, paint, and placental transport to the fetus. The
uptake/biokinetic model calculates the uptake and blood lead levels for the most sensitive
population, children ages 0 to 6 years old. EPA uses a blood lead level of 10 micrograms per
deciliter (ug/dl) as the benchmark to evaluate lead exposure.

Current use

The current visitor, student, and recreational person at the NC state site were assumed to be
potentially exposed to chemicals in the surface soil only. There are no current exposures to
groundwater, therefore groundwater risks were not evaluated under a current use scenario. Table
6-5 presents the current carcinogenic risk, Table 6-6 presents the current Hazard Index.

Future use

The future use scenario considers the possibility that future on-site or nearby residents are
exposed to chemicals in the groundwater and surface soils. Consumption of the water from the
contaminated plume would result in an unacceptable risk to human health and the environment.
Table 6-5 lists the lifetime cancer risk, and Table 6-6 provides the total hazardous index for
future senario.

Contaminant Risk

The quantified carcinogenic risk and non-carcinogenic hazard indices by contaminant are provided
in Table 6-7 and 6-8 respectively.

Potential Risk Associated with Radionuclides

The radionuclides associated with the NC State site, carbon-14 and tritium, were found at
concentrations above their natural background concentrations. However, the levels of carbon-14
and tritium at the Site fall below the limits for release to the environment (800,000 pCi/L for
carbon-14 and 3,000,000 pCi/L for tritium) and the concentration limits in public drinking water
supplies which are 3,200pCi/L for carbon-14 and 60,000 pCi/L for tritium. The beta particle
activity is also below the MCL of 4 mrem/yr.

Radionuclide Shallow Aguifer Deep Aguifer
Tritium 0.0614 mrem/yr 0.199 mrem/yr

Carbon-14 0.877 mrem/yr 0.877 mrem/yr

The calculated lifetime risk associated radionuclides at the Site which EPA calculates by
integrating intakes over a 30 year time period to account for the length of time people
live in one residence, is provided below.

Radionuclide Shallow Aguifer Deep Aguifer

Tritium 2x10 -6 5x10 -6
Carbon-14 1x10 -5

Total hazard indices for the hypothetical future exposure scenario exceeded 1.0 for the
ingestion of groundwater, however hazard indices for soils fall below benchmark level of 1.0.

-------
                                         Table 6-6

           Total Hazard Index Using Reasonable Maximum Exposure Concentrations
                                Current and Future Scenarios
                         Current Visitor
Current Recreational
       Person
Future Resident
   Exposure   Current    Child    Youth             Child    Youth             Child    Youth
    Medium    Student     1-6     7-16     Adult     1-6      7-16   Adult      1-6      7-16   Adult
Surface soil   0.02
                         0.002    0.001    0.001     0.1
                                                              0.03   0.02
                                                                                0.2
                                                                                         0.04    0.02
Groundwater     NE
- Shallow
                          NE
                                   NE
                                            NE
                                                      NE
                                                               NE     NE
                                                                                2022     1358     853
Groundwater
- Deep
                NE
                          NE
                                   NE
                                            NE
                                                      NE
                                                               NE     NE
                                                                                 42
                                                                                          28
                                                                                                   18
Total
               0.02
                         0.002    0.001    0.001
                                                     0.1     0.03   0.02
                                                                                2064     1386     871
   NE = Not evaluated in this scenario.

-------
                                           Table 6-7

                          Carcinogenic Risks for Substances of Concern
                                  (Reasonable Maximum Concentration)
                                   That Pose a Carcinogenic Risk
                                 Exceeding One in One Million  (10  -6)
Exposure Medium
Current
Student
  Current
Recreational
  Person
Current
Visitor
                                                  Future Resident
  Surface Soil
                          NC
                                          NC
                                                           NC
                                                                                 NC
Groundwater - Shallow
                          NE
                                          NE
                                                           NE        Benzene  (7  x  10  -3)
                                                                     Bromodichloromethane  (3  x 10  -4)
                                                                     Bromoform (5  x  10  -4)
                                                                     Carbon Tetrachloride  (1  x 10  -2)
                                                                     Chloroform  (9 x  10 -2)
                                                                     Dibromochloramethane  (5  x 10  -6)
                                                                     1,1-Dichloroethene,  (3 x 10  -4)
                                                                     Methylene Chloride (2 x  10 -3)
                                                                     1,1,2,2-Tetrachloroethane (7  x  10 -4)
                                                                     Tetrachloroethene  (5 x 10 -3)
                                                                     1,1,2-Trichloroethene  (1 x 10 -1)
                                                                     Trichloroethene  (4 x 10  -4)
                                                                     Vinyl Chloride  (1  x 10 -4)
                                                                     Isophorone  (9 x  10 -6)
                                                                     Dieldrin  (7 x 10 -6)
Groundwater - Deep
                           NE
                                         NE
                                                          NE
                                             Arsenic  (3 x 10 -3)
                                             Benzene  (4 x 10 -6)
                                             Bromodichloromethane  (5 x  10  -5)
                                             Carbon Tetrachloride  (9 x  10  -5)
                                             Chloroform  (8 x 10 -4)
                                             1,2-Dichloroethane  (4 x 10  -6)
                                             Methylene Chloride  (8 x 10  -6)
                                             1,1,2,2-Tetrachloroethane  (2  x  10  -5)
                                             Tetrachloroethene  (5 x 10  -6)
                                             Trichloroethene  (6 x 10 -6)
NC = Not of concern; did not exceed 1 x 10 -6 risk.
NE = Not evaluated.

-------
                                               Table  6-8
                              Noncarcinogenic Risks  for  Substances  of Concern
                                   (Reasonable Maximum Concentration)
                                Where Pathway Hazard Index Exceeds  One
Exposure Medium
Current
Student
   Current
Recreational
    Person
Current
Visitor
                                                                            Child 1-6
Future Resident

 Youth 7-16
                                                                                                                                      Adult
Surface Soil
                          NC
                                         NC
                                                      NC
                                                                                NC
                                                                                                              NC
                                                                                                                                        NC
Groundwater - Shallow
                          NE
                                         NE
                                                      NE
                                                   Barium (0.9)
                                                  Chromium (0.2)
                                                  Manganese  (256)
                                                    Nickel (0.2)
                                                    Acetone(15)
                                              Bromodichloromethane  (2)
                                                   Bromoform (0.2)
                                             Carbon Tetrachloride  (790)
                                                  Chlorobenzene  (2)
                                                  Chloroform (806)
                                              1,1-Dichloroethene  (0.2)
                                              1,2-Dichloroethene  (0.4)
                                              1,2-Dichloropropane  (14)
                                              Methylene  Chloride  (38)
                                               Tetrachloroethene  (64)
                                                    Toluene  (0.7)
                                              1,1,2-Trichloroethane  (4)
                                                  Trichloroethene  (27)
                                                    Isophorone  (0.2)
                                                                       Barium (0.6)
                                                                     Chromium (0.1)
                                                                     Manganese (172)
                                                                       Nickel (0.2)
                                                                     Acetone (10)
                                                                 Bromodichloromethane (1)
                                                                     Bromoform (0.2)
                                                                Carbon  Tetrachloride  (531)
                                                                     Chlorobenzene  (2)
                                                                     Chloroform (542)
                                                                1,1-Dichloroethene  (0.1)
                                                                1,2-Dichloroethene  (0.3)
                                                                1,2-Dichloropropane  (9)
                                                                Methylene  Chloride  (26)
                                                                 Tetrachloroethene  (43)
                                                                     Toluene (0.5)
                                                                1,1,2-Trichloroethane (3)
                                                                    Trichloroethene  (18)
                                                                     Isophorone (0.1)
                                                                                 Barium (0.4)
                                                                               Manganese (108)
                                                                                Nickel (0.1)
                                                                                Acetone (6)
                                                                          Bromodichloromethane (0.8)
                                                                                 Bromoform (0.1)
                                                                           Carbon Tetrachloride (333)
                                                                                Chlorobenzene (1)
                                                                                 Chloroform (340)
                                                                             1,2-Dichloroethene (0.2)
                                                                             1,2-Dithloropropane (6)
                                                                             Methylene Chloride (16)
                                                                              Tetrachloroethene (27)
                                                                                  Toluene (0.3)
                                                                              1,1,2-Trichloroethane  (2)
                                                                                Trichloroethene (11)

-------
                                            Table 6- 8
                          Noncarcinogenic Risks for Substances of Concern
                                 (Reasonable Maximum Concentration)
                               Where Pathway Hazard Index Exceeds One
Exposure Medium
Current
Student
   Current
Recreational
    Person
Current
Visitor
                                                                          Child  1-6
 Future Resident

Youth 7-16
                                                                                                                                       Adult
Groundwater - Deep
                             NE
                                             NE
                               NE            Arsenic  (2 3)
                                             Chromium  (0.3)
                                              Manganese  (6)
                                              Acetone  (0.2)
                                         Bromodichloromethane  (0.3)
                                          Carbon Tetrachloride  (5)
                                              Chloroform  (7)
                                        1,2-Dichloropropane  (0.4)
                                        Methylene Chloride  (0.1)
                                         Trichloroethene  (0.2)
                                                                Arsenic  (16)
                                                               Chromium  (0.2)
                                                                Manganese  (4)
                                                                Acetone  (0.1)
                                                          Bromodichloromethane  (0.2)
                                                           Carbon Tetrachloride  (3)
                                                               Chloroform  (4)
                                                           1,2-Dichloropropane  (0.3)
                                                          Trichloroethene  (0.1)
                                                                           Arsenic (10)
                                                                           Chromium (0.1)
                                                                           Manganese  (2)
                                                                      Bromodichloromethane (0.1)
                                                                        Carbon Tetrachloride  (2)
                                                                           Chloroform (3)
                                                                      1,2-Dichloropropane  (0.2)
NC  =  Not of concern; did not exceed a hazard index of 1 in this pathway
NE  =  Not evaluated

-------
E. Environmental Assessment

Risk to terrestrial wildlife was evaluated qualitatively based on the potential for exposure and
on the available toxicity information for the chemicals of potential concern. There is a
potential for several of the chemicals of potential concern to be toxic to numerous terrestrial
species, as well as a potential for several of these chemical to bioaccumulate and to biomagnify
though the terrestrial food chain, however the risks to terrestrial receptors are expected to be
low based on the low potential for exposure.

No contaminants in groundwater (presuming groundwater discharges to surface water) exceeded
federal and regional WQC. The results show that acute or chronic adverse effects are not
expected for aguatic life inhabiting Richland Creek.

F. Conclusions

The NC State Site has one primary media of concern, which is groundwater. The surface soils
were evaluated and the resulting determination was that the surface soils posed no substantial
risk to human health or the environment. The sub-surface soils on the other hand were found to
be a continuing source of contamination to the groundwater and should be addressed.

Actual or threatened releases of hazardous substances from this Site via the groundwater if not
addressed by implementing the response action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the environment.

VII. APPLICABLE RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)

Section 121(d) of CERCLA, as amended by SARA, requires that remedial actions comply with
requirements or standards set forth under Federal and State environmental laws. The
requirements that must be complied with are those that are applicable or relevant and
appropriate to the (1) potential remedial actions, (2) location, and (3) media-specific
chemicals at the Site.

Applicable requirements are those requirements specific to the hazardous substance, location,
and/or contemplated remedial action, that are, or will be, related to the Site. These
requirements would have to be met under any circumstance. Relevant and appropriate requirements
are those requirements that address problems or situations sufficiently similar to those
encountered at the Site, so that their use is well suited to the Site, but for which the
jurisdictional prerequisites have not been met.

This Section examines the cleanup criteria associated with the contaminants found and the
environmental media contaminated.

A. Action-Specific ARARs

Action-specific ARARs are technology-based, establishing performance, design, or other similar
action-specific controls or regulations on activities related to the management of hazardous
substances or pollutants. Potential action-specific ARARs/are presented in Table 7-1.

B. Location-Specific ARARs

Location-specific ARARs are design requirements or activity restrictions based on the
geographical or physical positions of the Site and its surrounding area. Potential location-
specific ARARs are presented in Table 7-2.

-------
Standard, Requirements, Criteria, or
          Limitations
          Table 7-1
POTENTIAL ACTION-SPECIFIC ARARs
     NC STATE LOT 86 SITE

                  Citation
Federal
Disposal - Discharge to Surface Water/POTW

Clean Water Act

Requires use of Best Available Treatment
Technology (BATT)
National Pollutant Discharge Elimination
System Permit Regulations
Discharge must be consistent with the
requirements of a Water Quality Management
Plan approved by EPA

STATE
North Carolina Groundwater Standards

Wastewater Discharge to Surface Waters

North Carolina Air Pollution Control
Requirements

North Carolina Water Quality Standards

North Carolina Sedimentation Control Rules

North Carolina Solid Waste Management Rules
             33 USC 1351-1376
             40 CFR 122
             40 CFR 122
             (Subpart C)
             40 CFR 122


             NCAC 15A-2L

             NCAC 15A-2H

             NCAC 15A-2D,  2H & 2Q


             ISA NCAC 2B

             ISA NCAC 4

             ISA NCAC 13 B
                          Description
Use of best available technology economically achievable is required to
control discharge of toxic Pollutants to POTW

Use of best available technology economically achievable is required to
control discharge of toxic pollutants discharged to surface waiers
                                     Discharge,  must comply with EPA-approved Water Quality Management
                                     Plan
Groundwater quality standards, regulates injection wells

Regulates surface water discharge

Air pollution control air quality and emissions standards


Surface water quality standards.

Requirements for prevention of sedimentation pollution.

Siting and design requirements for hazardous waste TSDs
  Applicable or Relevant &
        Appropriate
Relevant & Appropriate



Applicable




Relevant & Appropriate


Applicable

Applicable

Applicable


Relevant and Appropriate

Relevant and Appropriate

Relevant and Appropriate

-------
                              Table 7-2
                   POTENTIAL LOCATION-SPECIFIC ARARs
                           NC STATE LOT 86 SITE
                                                                                         Description
RCRA Location Standards                             4 OCFR 2 64.18(b)      A treatment/storage/disposal/ (TSD)  facility must  be designed,  constructed,     May be  relevant  and appropriate if
                                                                         operated,  and maintained to avoid washout  on  a  100  year floodplain.             an onsite  TSD  facility is required
                                                                                                                                                         as part  of overall  remediation and
                                                                                                                                                         it exists  within the 100 year
                                                                                                                                                         floodplain.

Fish and Wildlife  Conservation Act                 16USC 2901 et  seq.   Requires states to identi fy signi fleant  habitats  and develop conservation      Confirmation with the responsible
                                                                         plans  for these areas.                                                          state agency regarding the site
                                                                                                                                                         being located  in one of these
                                                                                                                                                         significant habitats ins required.

Floodplain Management  Executive Order   Executive Order 11988; 40  CFR   Actions that are to occur in  floodplain  should  avoid adverse effects,          Remedial actions are to prevent
                                                    6.302                minimi ze potential harm, restore and preserve natural and beneficial value     incursion  of contaminated
                                                                                                                                                         groundwater onto forested
                                                                                                                                                         floodplain
Wetlands Management  Executive  Order     Executive Order 11990;  4 OCFR    Action to minimize the destruction, loss  or  degradation of weHands            Potential  remedial  alternatives
                                                    6.302                                                                                                within wetlands.   Requirement is
                                                                                                                                                         relevant and appropriate.

STATE
North Carolina Solid Waste  Management Rules     15A NCAC 13B.0500       Siting requirements for solid waste disposal  units.

-------
                                                        Table 7-3
                                            POTENTIAL CHEMICAL-SPECIFIC ARARS
                                             NC STATE UNIVERSITY LOT 86 SITE
                                                                                             Description
Federal
Safe Drinking Water Act
                                                                                                                                   The  MCLs for organic & inorganic contaminants  are
                                                                                                                                   relevant and appropriate for groundwater at  the  site
                                                                                                                                   since  it is it potential water source
Primary Maximum                     40 CFR 142             Primary MCLs are  adopted for the protection of human     Relevant  &
Contaminant Levels                                         health but include  an  analysis of feasibility & cost of  Appropriate
                                                           attainment

                                                           EPA has also established Maximum Contaminant level
                                                           Goals  (MCGLs).  The nonenforceable standards are
                                                           based on health criteria.   The MCGLs are goals for the
                                                           nation's water supply

National Secondary Drinking Water   40 CFR 143
Standards
                                           Stat. 642 (1986)       no known  or  anticipated adverse health effects            Appropriate contaminants are relevant & appropriate  for
                                                                                                                                          groundwater at the site since it is  a  potential
North Carolina Drinking Water  Act



North Carolina Drinking Water  and      15A NCAC 2L         Establishes groundwater  class!fication and water             Applicable    Guidelines for allowable levels of toxic  organic  and
Groundwater Standards                                      quality standards.                                                          inorganic compounds in groundwater used for
                                                                                                                                       drinking water.
North Carolina Surface Water  Effluent   15A NCAC 2B.04 00    Establishes limits  and guidelines for effluent               applicable     May be applicable if treated groundwater  is
Limitations                                                 discharged to waters  of the state.                                           discharged to surface waters.

North Carolina Air Pollution  Control   15A NCAC 2D, 2H, & 2Q  Regulates ambient air quality and establishes air
Regulations                                                   quality standards for hazardous air pollutants.

-------
 Standard, Requirements
  Criteria, or Limitations
Surface Water

Clean Water Act

Water Quality Criteria
                                          Description
Applicable
or relevant

appropriate
40 CFR 131
Air
Clean Air Act
National Emission  &  Standards for
Hazardous Air
Pollutants
                                                               Sets  primary and secondary air standards  at  levels to               Will be relevant  &  appropriate if on-site treatment
                                                               protect  public health & welfare                        Relevant &    units are part  of remedial action
                                                                                                                      Appropriate
                 Provides  emission standards for hazardous air
                 pollutants  for which no ambient air quality standard
                 exists                                                  Relevant &
                                                                         Appropriate
           Will be  relevant  & Appropriate if on-site treatment
           units are  put  of  remedial action

-------
Federal classification guidelines for groundwater are as follows:

• Class I: Groundwater that is irreplaceable with no alternative source or is
ecologically vital;

• Class II: A - Groundwater currently used for drinking water;

B - Groundwater potentially available for drinking water;

• Class III: Groundwater not considered Class IIA.

State classification guidelines are based on best usage (NCAC 2L.0201). Under the State system
the aguifer is considered Class GA groundwater, existing or potential source of drinking water
supply for humans under the state system.

C. Chemical-Specific ARARs

Chemical-specific ARARs include those laws and regulations governing the release of materials
possessing certain chemical or physical characteristics, or containing specified chemical
compounds. These reguirements generally set health or risk-based concentration limits or
discharge limitations in various environmental media for specific hazardous substances,
contaminants, and pollutants. Potential chemical-specific ARARs are listed in Table 7-3.

VIII. REMEDIAL ACTION OBJECTIVES

A. Groundwater

Based on the results of the RI, the baseline risk assessment and considering the reguirements
for risk reduction, risk-based remediation levels, and the ARARs, the remedial action objectives
specifically developed for groundwater at the Site are presented in Table 8-1. The objectives
in establishing the remediation levels were:

• Prevent migration of contaminants to surface water that would result in
contamination to levels greater that the Ambient Water Quality Criteria (AWQC).

• Control future releases of contaminants to ensure protection of human health and the
environment (SARA Section 121 [d]).

• Permanently and significantly reduce mobility, toxicity, or volume of characteristic
hazardous-waste with treatment (SARA Section-121(d])

The final remediation levels were selected as the most conservative of the federal and state
chemical-specific ARARs, and if a standard did not exist, the risk-based goals were applied.
However, the average background concentration was selected as the remediation level if it
exceeded the most conservative level.

B. Extent of contamination Above Remediation Levels

The chemical groups found above the remediation levels in groundwater are volatile organics and
metals. The approximate locations of the contaminant plumes are shown in Figures 8-1, 8-2, 8-3,
and 8-4. The estimated volume of groundwater contamination 300,000 gallon. The extent of soil
contamination is primarily below surface in northwest corner of the landfill in the vicinity of
the disposal trenches with an estimated volume 12,000 cubic yards. The most prevalent chemicals
present were VOCs.

-------
                             TABIiE 8-1
            REMEDIAL ACTION OBJECTIVES FOR GROUNDWATER
                 NC STATE UNIVERSITY LOT 86 SITE
                      RALEIGH, NORTH CAROLINA
       Contaminant
Remediation
Level (Ig/1)
Basis
         Benzene
      1       NC Groundwater Quality Standard
              (15NANC 02L)
    Carbon Tetrachloride
              Contract Quantitation limit
              (CRQL)
       Chloroform
              Contract Quantitation limit
              (CRQL)
    Methylene Chloride
              NC Groundwater Quality Standard
              (15NANC 02L)
    Tetrachloroethene
              Contract Quantitation limit
              (CRQL)
         Acetone
      700     NC Groundwater Quality Standard
              (15NANC 02L)
    Bromodichloromethane
              Contract Quantitation limit
              (CRQL)
    1,2-Dichloropropane
              Contract Quantitation limit
              (CRQL)
    1,1,2-Trichloroethane
              Contract Quantitation limit
              (CRQL)
     Trichloroethene
              NC Groundwater Quality Standard
              (15NANC 02L)
        Manganese

         Arsenic
      370     Background Concentration

      10      Contract Quantitation limit
              (CRQL)

-------
IX. DESCRIPTION OF ALTERNATIVES

Figure 9-1 summarizes the technologies considered for remediating the contamination, at the
Site. The table also provides the rationale as to why certain technologies were not retained
for further consideration after the initial screening.

A. Remedial Alternatives to Address Soil Contamination

The following alternatives were developed to address subsurface soil contamination at the Site:

Alternative 1: No Action

Alternative 2: Institutional Action

Alternative 3: Containment/Capping

Alternative 4: Soil Vapor Extraction

Alternative 5: On-Site incineration

Alternative 6: Low Temperature Thermal Desorption

Alternative 7: In-situ Mixing and Encapsulation

The remedial alternatives to address soil contamination are discussed below.

Alternative 1: No Action

The no action alternative for soils provides a baseline for comparing other alternatives. No
remedial activities would be implemented, long-term human health and environmental risks for
the site would essentially be the same as those that currently exist.

Total Capital Costs $ 0
Present Worth 0 & M Costs $475,000
Total Present Worth Costs $475,000

Alternative 2: Institutional Controls

This alternative is similar to Alternative No. 1 except that deed restrictions plus physical
barriers would be used to restrict access to the site. Deed restriction would include zoning
ordinances that prohibit construction on, or use of, the site during the time that the soil
remains contaminated above cleanup goals. Physical barriers would include fencing, signs, etc.
to prevent access the site.

Total Capital Costs $ 59,100
Present Worth 0 & M Costs $641,820
Total Present Worth Costs $700,920

Alternative 3: Containment/Capping

Containment by capping, would involve the installation of an impervious layer over the area of
contaminated soil (considered to be an area of approximately 40,000 sguare feet) and development
of a stormwater management system to route stormwater off the cap in an acceptable manner.

Total Capital Costs $ 550,000
Present Worth 0 & M Costs $ 641,820
Total Present Worth Costs $1,191,820

Alternative 4: Soil Vapor Extraction

This technology involves creating a movement of air through the soil via series of injection
wells. The movement of air would then vaporize the VOCs and would also assist in oxidizing any
metals present. The vaporized gas would then be removed from the ground by a series of vacuum

-------
wells. This alternative would remediate the soils in the unsaturated zone vertically between
the landfill trenches and the groundwater table. The effectiveness of the system will be
dependent on the soil permeability allowing air to move through soils. The precise layout and
extent of the system would have to be determined by further investigation and pilot test.

Total Capital Costs $ 500,000
Present Worth 0 & M Costs $1,842,677
Total Present Worth Costs $2,342,677

Alternative 5: On-site Incineration

On-site incineration involves excavation and stockpiling of the contaminated material. The
excavated material would then be conditioned prior to being incinerated on-site. Properly
prepared material when incinerated results in a clean ash residue. The excavated area would be
backfilled with the ash supplemented with clean imported soil. The incineration would take
place with a mobile incinerater which would be brought to the site and set up, together with a
soil conditioning plant, to receive the contaminated soil. It would be operating as a continuous
process with a through put of about 50 cubic yards per day. The incineration would take about 1
year to complete, not including the test burn, mobilization, and start-up.

Total Capital Costs $ 500,000
Present Worth 0 & M Costs $10,300,000
Total Present Worth Costs $10,800,000

Alternative 6: Low Temperature Thermal Desorption

The process consists of a heated chamber with temperatures of 700 to 900 degrees Fahrenheit.
Contaminated soil are excavated, preconditioned, broken up, and then fed into the chamber in a
continuous operation. Contaminants are driven off the soil by the heat and are captured in the
next stage (bag house, GAG, or other eguivalent system). The treated soil is placed back in the
ground and the capture contaminants are sent off-site for disposal to an authorized incinerator
or for regeneration.

Total Capital Costs $ 800,000
Present Worth 0 & M Costs $ 4,950,000
Total Present Worth Costs $ 5,750,000

Alternative 7: In-situ Mixing and Encapsulation

The soils will be mixed initially within the bore hole and the VOCs that are released as a
result of the mixing will be captured via a specially designed bore hole shroud, and
treated. The treatment may include but not be limited to liquid vapor separation, in-line
prefiltration for dust and particulate removal, followed by parallel activated carbon filter
banks. The remaining contaminants will be solidified in-situ using various pozzolan-portland
cement based formulations delivered to and dispersed within the soil column as a grout.

Total Capital Costs $ 931,000
Present Worth 0 & M Costs $ 0
Total Present Worth Costs $ 931,000

B. Remedial Alternatives to Address Groundwater Contamination

The following alternatives were developed to address groundwater contamination at the Site:

Alternative 1: No Action

Alternative 2: Institutional

Alternative 3: Groundwater Extraction, Treatment, and Discharge

Alternative 4: Biotreatment

Alternative 5: Intrinsic Degradation

-------
The remedial response actions to address groundwater contamination are discussed below.

Alternative 1: No Action

This alternative provides the baseline case for comparing remedial actions for groundwater and
the level of improvement achieved. The groundwater will be monitored and recorded semiannually
and a status report issued every 5 years for 30 years. All samples would be collected and
analyzed for the contaminants of concern.

There are no capital costs associated with this alternative. Operating costs are based on the
review of Site conditions every five years for a period of thirty years. There would be no
maintenance costs.

Total Capital Costs $ 0
Present Worth 0 & M Costs $ 300,000
Total Present Worth Costs $ 300,000

Alternative 2: Limited Action

This alternative is identical to the no-action alternative described above except that it
includes implementation of institutional controls. Those institutional controls would include
deed restrictions to restrict access to contaminated groundwater on the site. Deed restrictions
could included zoning ordinances that prohibit use of groundwater at the site and in areas
downgradient to Richland Creek, during the time that the groundwater is not usable.

Total Capital Costs $ 0
Present Worth 0 & M Costs $ 500,000
Total Present Worth Costs $ 500,000

Alternative 3: Groundwater Extraction, Treatment, Discharge

This alternative includes extraction of the contaminated groundwater, VOC removal using air
stripping, followed by carbon adsorption for the removal of organics, and discharge of the
treated effluent. Groundwater monitoring is reguired to evaluate remediation as it progresses.
A period of 30 years is assumed for complete remediation. If an offsite discharge option is
selected the treated effluent would meet the surface water discharge criteria of the NPDES
permit that would be obtained during the remedial design phase. The groundwater system will be
designed to operate 24 hours per day. System controls would allow for complete automatic
operation with minimal operator attention. Alarms and switches would be furnished for fail-safe
operation.

Total Capital Costs $ 343,500
Present Worth 0 & M Costs $ 1,762,190
Total Present Worth Costs $ 2,100,000

Alternative 4: Biotreatment of Groundwater

Biotreatment of the groundwater is a closed-loop system consisting of nutrients and possibly a
carbon source addition into the upgradient groundwater through and an infilltration trench to
facilitate bioremediation of the groundwater contaminants. The groundwater will be pump from a
down gradient location using three extraction wells to control flow and enable groundwater
sampling, and recirculation of the extracted water. This alternative would also include long
term monitoring.

Total Capital Costs $ 209,000
Present Worth 0 & M Costs $ 1,356,830
Total Present Worth Costs $ 1,600,000

Alternative 5: Intrinsic Degradation

Intrinsic degradation involves the transformation of site contaminants into a innocuous state
naturally, without any external aids or treatments. Simply stated, chemicals present would
transform chemically into a harmless state. To guantify the viability of this option an

-------
evaluation of contaminant transformation under environmental conditions has to be conducted.

              Total Capital Costs           $   100,000
              Present Worth 0 & M Costs     $   500,000
              Total Present Worth Costs     $   600,000

X.  SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The remedial alternatives to address contamination were evaluated using the nine evaluation
criteria as set forth in the NCP, 40 CFR °300.430(e)(9).   A brief description of each of the
nine evaluation criteria is provided below.

THRESHOLD CRITERIA

1.   Overall Protection of Human Health and the Environment addresses how an alternative as a
whole will protect human health and the environment.  This includes an assessment of how the
public health and the environmental risks are properly eliminated, reduced, or controlled
through treatment, engineering controls, or controls placed on the property to restrict access
and (future) development.  Deed restrictions are examples of controls to restrict development.

2.   Compliance with Applicable or Relevant and Appropriate Reguirements (ARARs) addresses
whether or not a remedy complies with all state and federal environmental and public health laws
and reguirements that apply or are relevant and appropriate to the conditions and cleanup
options at a specific site. If an ARAR cannot be met, the analysis of the alternative must
provide the grounds for invoking a statutory waiver.

PRIMARY BALANCING CRITERIA

3.   Long-term Effectiveness and Permanence refers to the ability of an alternative to maintain
reliable protection of human health and the environment over time once the cleanup levels have
been met.

4.   Reduction of Toxicity, Mobility, and Volume are the three principal measures of the overall
performance of an alternative.  The 1986 amendments to the Superfund statute emphasize that,
whenever possible, EPA should select a remedy that uses a treatment process to permanently
reduce the level of toxicity of contaminants at the site; the spread of contaminants away from
the source of contaminants; and the volume, or amount, of contamination at the Site.

5.   Short-term Effectiveness refers to the likelihood of adverse impacts on human health or the
environment that may be posed during the construction and implementation of an alternative until
cleanup levels are achieved.

6.   Implementability refers to the technical and administrative feasibility of an alternative,
including the availability of materials and services needed to implement the alternative.

7.   Cost includes the capital (up-front) cost of implementing an alternative, as well as the
cost of operating and maintaining the alternative over the long-term, and the net present worth
of both the capital and operation and maintenance costs.

MODIFYING CRITERIA

8.   State Acceptance addresses whether, based on its review of the RI/FS and Proposed Plan, the
State concurs with, opposes, or has no comments on the alternative EPA is proposing as the
remedy for the Site.

9.   Community Acceptance addresses whether the public concurs with EPA's proposed plan.
Community acceptance of this proposed plan will be evaluated based on comments received at the
public meetings and during the public comment period.

These evaluation criteria relate directly to reguirements in Section 121 of CERCLA, 42 USC
Section 9621, which determine the overall feasibility and acceptability of the remedy.

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Threshold criteria must be satisfied in order for a remedy to be eligible for selection.
Primary balancing criteria are used to weigh major trade-offs between remedies.   State and
community acceptance are modifying criteria formally taken into account after public comment is
received on the proposed plan.  Table 10-1 provides a summary of all the alternatives.  The
comparative analysis of the potential remedial alternatives to address Site contamination are
discussed below.

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                             TABIiE 10-1
                    Remedial Action Alternatives
             NC State University Lot 86 Superfund Site
Alternative Description
IS No Action
2S Institutional
Control
3S Containment/Capping
4S Soil Vapor
Extraction
5S On-Site Incineration
6S Low Temperature
Thermal Desorption
7S Sub-Surface: in-situ
Mixing & Encapsulation
1G No Action
2G Limited Action
3G Groundwater

$
$
$
$
$
$
$
$
$
$
Cost
475,000
700,920
1,191,820
2,342, 677
10,800,000
5,750,000
931,000
300,000
500,000
2,100,000
                     Extraction Treatment
                     and Discharge

4G                     Biotreatment of       $   1,600,000
                        Groundwater

5G                        Intrinsic          $     600,000
                         Degradation

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A. Comparative Analysis of Soil Alternatives

The following alternatives were subjected to detailed analysis for soil remediation:

Alternative 1: No Action

Alternative 2: Insitutional Control

Alternative 3: Containment /Capping

Alternative 4: Soil Vapor Extraction

Alternative 5: On-Site Incineration

Alternative 6: Low Temperature Thermal Desorption

Alternative 7: In-situ Mixing and Encapsulation

Overall Protection of Human Health and the Environment

Each alternative was evaluated to determine whether it is likely to effectively mitigate and
minimize the long-term risk of harm to public health and the environment currently presented at
the Site. Alternative 1 does not provide any additional protection from site contaminants.
Alternative 2 would provide a greater degree of protection than No Action, however the
protection provided would not be much better than what currently exists at the Site.
Alternatives 3 and 7 would prohibit the infiltration of site runoff which could potentially add
to the groundwater contamination, thereby providing good overall protection of human health and
the environment. Alternative 7 provides a slightly better degree of protection than Alternative
3 because in addition to reduced permeablity this alternative will also reduce the concentration
of the VOCs present in the trenches. The greatest degree of overall protection that could be
provided, would only be achieved by the removal of contamination from the soils. Alternatives 4,
5, and 6 seek to remove contaminants from the soils providing the best overall protection.

Compliance With ARARs

The no action and the Institutional Controls alternatives would not comply with ARARs, and would
continue to allow contaminants to leach into the groundwater. Alternative 3 does not involve
treatment that would achieve ARARs either; however, this alternative by preventing further
migration of contamination from the disposal trenches, is consider to be protective of
groundwater. Alternative 7 provides treatment of VOCs and may provide some ARAR compliance
in-relation to VOCs. Alternatives 4, 5, and 6 included treatment options that will reduce the
level of contamination in the soils to meet ARARs. Alternative 4 would reguire a treatibility
study to determine if the level of contamination would be reduced to meet ARARs.

Long-term Effectiveness and Permanence

In Alternatives 1 and 2, will continue to allow contaminants to allow contaminants to migrate
off-site; therefore they are not considered to be permanent or provide reliable protection to
public health and the environment. Alternatives 3 and 7 prohibit further leaching from the
disposal trenches, thereby providing reliable protection and long term effectiveness.
Alternatives 5 and 6 will meet the remediation goals, providing the best degree of
protectiveness and permanence. The long term effectiveness and permanence of Alternative 4 is
uncertain.

Reduction of Toxicity, Mobility, and Volume

Alternatives 1 and 2 would not reduce the toxicity, mobility, or volume (T/M/V) of the
contaminants. Alternative 3 provides no reduction in toxicity or volume, however it does
provide some degree of reduction in the mobility of site contaminants. Alternatives 5 and 6
provide the maximum reduction of T/M/V. It is uncertain what degree of T/M/V Alternative 4 will
provide, however at this point it's expected results would fall between that of Alternatives 1
and 2 which provides no reduction in TMV and Alternatives 5 and 6. Alternative 7 will reduce
toxicity and volume of VOCs, and the mobility of the other contaminants present in the trenches

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along with the VOCs.

Short-term Effectiveness

Alternatives 1, 2 and 3 do not disturb the buried contaminants, thereby avoiding any increased
short term health and environmental risk to workers or nearby residents. Alternatives 4 and 7
involves an increased risk to on-site workers during installation, however the risk could be
easily controlled by the use of normal heath and safety practices.

Alternatives 5 and 6 provide the greatest degree of increased short term risk, because both
alternatives involve the excavation and storage of contaminated materials until the actual
treatment is completed.

Implementability

Alternative 1 reguires no further action and is readily implemented. Administrative and legal
actions reguired by Alternative 2 are easily implemented, particularly because the Site is owned
by the State of North Carolina. The cap reguired by Alternative 3 is easily constructed over
the area of contamination utilizing standard construction technigues. Alternative 4 will reguire
a Site specific treatability study, and the implementabilty of this alternative would depend
totally on the results of the treatabilty study. As a result of the number of unknowns
associated with the implemetability of this Alternative it is considered to be the most
difficult to implement. Alternatives 5 and 6 are very implementable, however they reguired a
large area to implement because of materials pre-processing and storage. Alternative 7 is very
implementable and has been used successfully at much larger sites.

Cost

Total present worth costs for the alternatives are presented in Table 10-1.

State Acceptance:

The State Recommends In-situ Mixing and Encapsulation as the soil remedy.

Community Acceptance:

The community is in favor of the soil remediation option of in-situ mixing and encapsulation.

B. Comparative Analysis of Groundwater Alternatives

The following alternatives were subjected to detailed analysis for groundwater remediation:

Alternative 1: No Action

Alternative 2: Limited Action

Alternative 3: Groundwater Extraction, Treatment,
and Discharge

Alternative 4: Biotreatment of Groundwater

Alternative 5: Intrinsic Degradation

Overall Protection of Human Health and the Environment

Each alternative was evaluated to determine whether it is likely to effectively mitigate and
minimize the long-term risk of harm to public health and the environment currently presented at
the Site. Alternative 1 does not eliminate any exposure pathways or reduce the level of risk.
Alternative 2 eliminates some exposure pathways, with a reduction in the potential risk of
groundwater ingestion and inhalation, however the potential for exposure still remains under a
future residential scenario. Alternatives 3 and 4 are active treatment technologies that seek
to remove contaminants from the groundwater, thereby being protective of human health and the
environment. Alternative 5 is a passive treatment technology which theorizes that the

-------
contaminants will attenuate naturally overtime. To date this treatment technology has not been
proven to be effective at the Lot 86 Site, however if proven effective, this alternative
initially would not provide any greater protection than Alternative 1, but over time contaminant
levels would attenuate providing adequate overall protection.

Compliance With ARARs

The no action and the limited action alternatives would not comply with ARARs. Alternative 3
would attain ARARs on the extracted groundwater, however there are some uncertainties about this
treatment technologies ability to extract all the contaminated groundwater from the aguifer.
Alternative 4 is expected to achieve a 80 to 90 percent reduction in level of contamination. It
is expected that residual levels of contamination will remain that may reguire waivers from
ARARs. Alternative 5 has not been shown to attain ARARS.

Long-term Effectiveness and Permanence

In Alternatives 1 and 2, contaminant migration through groundwater water discharge would
continue. In Alternative 3, there would be a maximum reduction in pathway exposure risk, and
further migration would be eliminated. Alternatives 4 as with Alternative 3 is expected to
reduce pathway exposure, however the reduction is expected to be less than that provided by
Alternative 3. Alternative 5 if proven to be effective at the Lot 86 Site, would provide long
term effectiveness and permanence. In the absence of that conclusive evidence Alternative 5 is
considered to provide the same level of effectiveness and permanence as Alternatives 1 and 2.

Reduction of Toxicity, Mobility, and Volume

Alternatives 1 and 2 would not reduce the toxicity, mobility, or volume (T/M/V) of the
contaminants. Alternative 3 provides the maximum reduction of T/M/V. In is uncertain what
degree of T/M/V Alternatives 4 and 5 will provide, however at this point their expected results
would fall between that of Alternatives 1 and 2 which provides no reduction in TMV and
Alternative 3.

Short-term Effectiveness

All of the alternatives can be implemented without significant risks to the community or on-site
workers and without adverse environmental impacts.

Implementability

Alternative 2, requiring deed restrictions presents no implementability problems. Alternative 3
could potentially require a NPDES permit or substantive compliance if the treated effluent is
discharged to surface water. Alternative 4 would require a site specific treatability study to
verify the viability or this alternative as well as a more tedious regulatory process because of
the closed loop system. Alternative 5 will require further modeling along with additional
monitoring, before this Alternative could be successfully implemented.

Cost

Total present worth costs for the groundwater alternatives are presented in Table 10-1.

Community Acceptance:

The community has expressed it's concern over the expenditure of additional funds associated
with the pump and treat option for groundwater when intrinsic degradation may be a cheaper
viable option.

XI. THE SEIiECTED REMEDY

Based upon consideration of the requirements of CERCLA, the NCP, the detailed analysis of the
alternatives and public and state comments, EPA has selected Alternatives 3G (groundwater pump
and treat) and 7S (In-situ Mixing and Encapsulation), as the remedy for this Site. At the
completion of this remedy, the risk associated with this Site has been calculated to be within
the accepted risk range determined to be protective of human health and the environment. The

-------
total present worth of the selected remedy is $ 3,031,000.00.

A. Soil Remediation

The soil component of the selected remedy will be in-situ mixing and encapsulation. The
technology involves a two stage process. The volatiles will be driven off and captured via a
specially designed bore hole shroud, and then treated in the first stage. The treatment may
include but not be limited to liguid vapor separation, in-line prefiltration for dust and
particulate removal followed by parallel activated carbon filter banks. The remaining
contaminants in the trenches will then be solidified in-situ, using various pozzolan-portland
cement based formulations delivered to and dispersed within the soil column as a grout. The
extent of encapsulation will be better defined during, the remedial design process, however
at a minimum the encapsulation shall extend to encompass a two foot radius around the confines
of the trenches. The Toxicity Characteristic Leaching Procedure (TCLP) (55 FR 11798, 1990) is
to be considered in the design of the soils encapsulation alternative.

B. Groundwater Remediation

Groundwater remediation will involve the extraction of the contaminated groundwater via
extraction wells. The extracted groundwater will be treated and discharged to either surface
water or the local POTW.

The treatment will consist of air stripping to remove volatile organics, and carbon adsorption
to remove organics. The groundwater system will operate 24 hours per day. System controls will
allow complete automatic operation with minimal operator attention. Long-term monitoring for
cleanup verification purposes and to track contaminant plume migration will be reguired. The
system is expected to operate 30 years; samples will be collected from existing wells on a
semi-annually basis for the first 5 years, and on an annual basis for the following 25 years.

The groundwater treatment system will also reguire monitoring and maintenance. Monitoring of
the treatment system will include periodic sampling of the influent and effluent from the
treatment system and analysis in accordance with the permit reguirements.

C. Retraction and Performance Standards

Location of extraction wells, pumping rates and method of discharge will be determined during
the remedial design.

Groundwater shall be treated until the Remediation objectives listed in Table 11-1 are attained
throughout the contaminant plume.

The goal of this remedial action is to restore the groundwater to its beneficial use. Based on
information obtained during the RI, and the analysis of all remedial alternatives, EPA and the
State of North Carolina believe that the selected remedy will be able to achieve this goal:

Groundwater contamination may be especially persistent in the immediate vicinity of the
contaminants, source, where concentrations are relatively high. The ability to achieve
remediation levels at all points throughout the area of attainment, or plume, cannot be
determined until the extraction system has been implemented, modified, as necessary, and plume
response monitored over time.

If the selected remedy cannot meet the specified performance standards, at any or all of the
monitoring points during implementation, the contingency measures and goals described in this
section may replace the selected remedy and goals for these portions of the plume. Such
contingency measures will, at a minimum, prevent further migration of the plume and include a
combination of containment technologies and institutional controls. These measures are
considered to be protective of human health and the environment, and are technically practicable
under the corresponding circumstances.

The selected remedy will include groundwater extraction for an estimated period of 30 years,
during which time the system's performance will be carefully monitored on a regular basis and
adjusted as warranted by the performance data collected during operation. Modifications may
include any or all of the following:

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     a)  at individual wells where remediation levels have been attained, pumping may be
         discontinued;

     b)  alternating pumping at wells to eliminate stagnation points;

     c)  pulse pumping to allow aguifer eguilibration and encourage adsorbed contaminants to
         partition into groundwater;

     d)  installation of additional extraction wells to facilitate or accelerate cleanup of the
         contaminant plume.

To ensure that cleanup continues to be maintained, the aguifer will be monitored at those wells
where pumping has ceased on an occurrence of at least every 2 years following discontinuation of
groundwater extraction.

If it is determined, on the basis of the preceding criteria and the system performance data,
that certain portions of the aguifer cannot be restored to their beneficial use, all of the
following measures involving long-term management may occur, for an indefinite period of time,
as a modification of the existing system:

     a)  engineering controls such as physical barriers, or long-term gradient control provided
         by low level pumping, as contaminant measure;

     b)  chemical-specific ARARs may be waived for the cleanup of those portions of the aguifer
         based on the technical impracticability of achieving further contaminant reduction;

     c)  institutional controls may be provided/maintained to restrict access to those portions
         of the aguifer which remain above remediation levels;

    d)    continued monitoring of specified wells; and

    e)    periodic reevaluation of remedial technologies for groundwater restoration.

The decision to invoke any or all of these measures may be made during a periodic review of the
remedial action, which will occur at 5 year intervals in accordance with CERCLA Section 121(c).
The remedial actions shall comply with all ARARs  (See Sections VII).

The implementation of the remedial action portion of the groundwater remedy will be delayed two
years from the date of this Record of Decision.  During that time, EPA will consider any new
evidence submitted by interested parties that the reduction of groundwater contamination is
occurring at the site by means of natural processes.  If analytical results such as but not
limited to a decrease of groundwater contamination or the existence of breakdown products of the
original contaminants is presented, EPA will consider a change in remedy.

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                       TABIiE 11-1
       REMEDIAL ACTION OBJECTIVES FOR GROUNDWATER
             NC STATE UNIVERSITY LOT 86 SITE
                 RALEIGH, NORTH CAROLINA
       Contaminant
Remediation
Level (Ig/1)
           Basis
        Benzene
                             1
               NC Groundwater Quality Standard
               (15NANC 02L)
  Carbon Tetrachloride
               Contract Quantitation limit
               (CRQL)
      Chloroform,
               Contract Quantitation limit
               (CRQL)
  Methylene Chloride
               NC Groundwater Quality Standard
               (15NANC 02L)
  Tetrachloroethene
               Contract Quantitation limit
               (CRQL)
      Acetone
                            700
               NC Groundwater Quality Standard
               (15NANC 02L)
Bromodi chloromethane
               Contract Quantitation limit
               (CRQL)
1, 2-Dichloropropane
               Contract Quantitation limit
               (CRQL)
1,1,2-Trichloroethane
               Contract Quantitation limit
               (CRQL)
  Trichloroethene
               NC Groundwater Quality Standard
               (15NANC 02L)
    Manganese

     Arsenic
   370

    10
Background Concentration

Contract Quantitation limit
(CRQL)

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                         Appendix I
                    RESPONSIVENESS SUMMARY

Responsiveness Summary Overview

The Responsiveness Summary is the official record of how the Agency responded to public comments
as a part of the decision making process.  The responsiveness summary also provides the decision
makers of the lead Agency with the public's views, so that they are considered in the final
decision.

This document is segregated into three components; summary of the community's involvement, the
Agency's response to comments received at the proposed plan public meeting and the Agency's
response to written comments received form concern parties during the process.

Background of Community involvement and Concerns

The public concerns regarding this Site have been minimal. This is probably the result of the
Agency's rather extensive community relations efforts, and the fact that the contamination at
the Site has remained on State land and has not effected any of the neighboring communities.

Two public meetings were held.  The first meeting was held on September 7, 1993 to discuss the
superfund process, and the second meeting was the proposed plan meeting on July 9, 1996. Several
fact sheets were prepared and distributed through out the process.  The Remedial Investigation
(RI) and Feasibility Study (FS )  reports along with the Proposed Plan were released to the
public in June of 1996.  All of these documents as well as the Administrative Record were made
available to the public. Announcements of each meeting were advertised in the local newspaper
and press releases prepared.

Public Meeting Comments

These are the community concerns that were expressed as a result of the July 9, 1996 proposed
plan public meeting are as follows:

Comment:  A gentleman stood,  and expressed his concern over the amount of time the process has
taken to this point. He has been aware and following the progress of the Site for over ten
years, and wanted to know if were at an impasse over what was to be done next.

Response:  A decision as to what remedy will be selected will occur within the next 60 days, and
that the ongoing debate is a part of the formal comment period where all comments are heard and
factored into the final decision.

Comment:  The gentleman first expressed his disagreement with the estimated cost of the
alternatives, and further went on to ask why the Agency would not consider the cheaper remedy of
intrinsic degradation if it had a potential of working.  Especially since the site contaminants
aren't posing a threat the human health or the environment at this time.

Response:  In the Agency's evaluation of the alternatives, we are required to consider all of
the nine criteria not cost alone.

Comment:  The gentleman further stated that as a member of the community that he wanted to cast
his vote for intrinsic degradation and if it was deem ineffective at a later date another remedy
could be selected.

Response:  It is the Agency's intent at this time to gather the opinion of the affected
community and factor those concerns and opinions into the final remedy selection.

Comment:  Another citizen cast a dissenting vote for pump and treat and a favorable one for
natural attenuation.  He further stated that he has managed two natural attenuation sites in
North Carolina and one was successfully remediated and one wap underway.

Comment:  A gentleman wanted to know what was the origin of the cost documentation.

Response:  The cost figures come from the University's contractor and that is what the

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contractor represented to the University as the cost of implementing these alternatives.

Comment: When were these cost provided to the University?

Response: The cost estimates are about a year and a half old.

Comment: Could the cost be twice that much or three times that much?

Response: I am unable to answer that question.

Comment: Another citizen expressed concern over the potential escalation of the cost and the
impact that would have on the taxpayers.

Comment: A gentleman expressing his concern over the amount of time it has taken to get to this
point wanted to know how much more time is the State requesting to demonstrate that natural
attenuation will work.

Response: Dave Lown of the State responded to the question. Dave stated without providing a
specific time frame that the State was experienced in this area and would be looking for
specific criteria and that it would not turn into a 20 year research project.

Comments: A gentleman stated that he was aware that the State had experience with petroleum
sites or sites with hydrocarbon not chlorinated or halloginated solvents, and that he has seen
less evidence where chlorinated solvents break down.

Response: Dave Lown responded by stating that a report was submitted to USEPA pertaining
specifically to situation at the Lot 86 Site, and that included a fairly extensive literature
review of the degradation pathways and mechanisms to the contaminants specific to our situation.

Comment: Concern was expressed over the effect the delay in action would have on the migration
of the plume, especially as the potential for the spread of the plume into the bedrock aquifer.
The citizen referenced a Camp Dresser & Mckee document prepare for the Agency stating that the
potential to cleanup the site is good considering the limited exposure to the bedrock aquifer.

Comment: It was asked if the introduction of natural attenuation was a delay tactic.

Response: Dave Lown responded stating that everyone is in agreement on the soils remediation
and that would proceed in a expeditious manner. The debate is over pump and treat which is a
long term process and that a one to two year delay will have minimal effect on the overall
process.

Comment: A gentleman asked what is the status of the radioactive portion of the site.

Response: Our investigation of the radioactive portion of the Site revealed that the low level
radioactive waste did not pose a threat. The risk fell within the acceptable risk range.

Comment: Does the site have any affect on the Wade Avenue road projects or the Centennial
Coliseum.

Response: From a risk scenario standpoint the only scenario that would present a problem would
be a residential scenario which included the ingestion of the groundwater. The currently
proposed projects are not threatened or affected by the Site.

Response: Duane Knudson of N.C. State University stated that they task it's hydrogeologist to
determine if there was an impact on those projects by site, and he felt the that site would not
effect the proposed projects.

Response to Written Comments

There were no written comments received during the comment period.

General Response to Comments

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Comments were received indicating the belief that natural attenuation is occurring or may occur
in the groundwater at the site.  Even though there is no conclusive evidence of the reduction of
contaminants by natural processes occurring at this time, EPA believes that a delay giving time
for interested parties to gather additional evidence is warranted. Therefore, the implementation
of the remedial action section of the groundwater remedy will be delayed two years from the date
of this Record of Decision.  During that time, EPA will consider any new evidence submitted by
interested parties that the reduction of groundwater contamination is occurring by means of
natural processes at the site.  If analytical results such as a decrease in groundwater
contamination or the existence of breakdown products of the original contaminants is presented,
EPA will consider a change in remedy to this Record of Decision.  EPA believes that during this
time, the remedial design and subseguent cleanup of the soils can continue; and that the two
year delay in the groundwater remedial action will not impact the overall speed of the cleanup.

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