Blades Groundwater Superfund Site Blades Sussex County Delaware Operable Unit 2 Record of Decision for Interim Action


BLADES GROUNDWATER SUPERFUND SITE
BLADES, SUSSEX COUNTY, DELAWARE

OPERABLE UNIT 2

RECORD OF DECISION
FOR INTERIM ACTION

United States Environmental Protection Agency
Region 3
1600 John F. Kennedy Boulevard
Philadelphia, PA 19103-2852

February 2024

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BLADES GROUNDWATER
SUPERFUND SITE OPERABLE UNIT 2
BLADES, SUSSEX COUNTY, DELEWARE

RECORD OF DECISION
FOR INTERIM ACTION

Table of Contents

1.	DECLARATION	1

2.	DECISION SUMMARY	4

I.	SITE NAME, LOCATION, AND DESCRIPTION	4

II.	SITE HISTORY AND ENFORCEMENT ACTIVITIES	4

III.	HIGHLIGHTS OF COMMUNITY PARTICIPATION	9

IV.	SCOPE OF THE SELECTED REMEDY	9

V.	SITE CHARACTERISTICS	10

A.	Physical Setting	10

B.	Geology	10

C.	Nature and Extent of Contamination	11

D.	National Historical Preservation Act	11

VI.	CURRENT AND POTENTIAL FUTURE LAND AND RESOURCE USES	11

VII.	SUMMARY OF SITE RISKS	12

A.	Human Health Risk Assessment Summary	13

B.	Summary of Ecological Risk Assessment	16

C.	Summary of Site Risks	16

VIII.	REMEDIAL ACTION OBJECTIVES	16

IX.	SUMMARY OF REMEDIAL ACTION ALTERNATIVES	17

X.	COMPARATIVE ANALYSIS OF ALTERNATIVES	20

A.	Criteria Used to Compare Cleanup Alternatives	20

B.	Detailed Analysis of Proposed Remedial Alternatives	21

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XI.	SELECTED REMEDY	26

A.	Summary of the Rationale for the Selected Remedy	27

B.	Summary of the Estimated Costs	28

C.	Performance Standards	28

D.	Expected Outcome of the Selected Remedy	28

XII.	STATUTORY DETERMINATIONS	28

A.	Compliance with Applicable or Relevant and Appropriate Requirements	29

B.	Cost-Effectiveness	29

C.	Utilization of Permanent Solutions and Alternative Treatment Technologies to
the Maximum Extent Practicable and Preference for Treatment as a Principal
Element	30

D.	Five Year Review Requirements	30

E.	Documentation of Significant Changes	30

3. RESPONSIVENESS SUMMARY	31

TABLES

Table 1 - Risk Findings

Table 2 - Remedial Alternatives Evaluated

Table 3 - Evaluation Criteria for Superfund Remedial Alternatives

Table 4 - Cost Estimate of Alternatives

FIGURES

Figure 1 - Site Location Map
Figure 2 - Site Layout

Figure 3 - 2021-2022 Residential Well Sampling
Figure 4 - Selected Remedy - Water Main Extension

APPENDICES

Appendix A-Administrative Record Index
Appendix B - ARARs and TBCs
Appendix C - Risk Assessment Calculations
Appendix D - Detailed Cost Estimate
Appendix E - DNREC Concurrence Letter

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RECORD OF DECISION FOR INTERIM ACTION

BLADES GROUNDWATER SUPERFUND SITE
OPERABLE UNIT 2

1. DECLARATION

Site Name and Location

The Blades Groundwater Superfund Site (Site) is located in Blades, Sussex County, Delaware.
The Site was placed on the National Priorities List (NPL) on September 3, 2020. The National
Superfund Database Identification Number is DEN000304203. For administrative purposes the
Site has been separated into two Operable Units. Operable Unit 1 (OU1) addresses
contaminated media Site-wide. Operable Unit 2 (OU2) addresses public exposure to
contaminants in private drinking water wells from contaminated groundwater. This Record of
Decision (ROD) for interim action only addresses the remedy for OU2. A remedy for OU1 will be
addressed in a separate and subsequent ROD.

Statement of Basis and Purpose

This ROD presents the selected interim remedial action (Selected Remedy) for OU2. The
Selected Remedy was chosen in accordance with the requirements of the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) 42 U.S.C. §§ 9601
et seq., as amended, and, to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R. Part 300. This decision document explains the
factual and legal basis for the Selected Remedy for OU2 at the Site. The information supporting
this decision is contained in the Administrative Record (AR) for the Site, which was developed in
accordance with Section 113(k) of CERCLA, 42 U.S.C. § 9613(k). This AR file is available for
review online at https://semspub.epa.gov/src/collection/03/AR67374. The AR file index
(Appendix A) identifies each document contained in the AR file upon which the selection of the
remedy is based. The signed ROD will become part of the AR for the Site.

The Delaware Department of Natural Resources and Environmental Control (DNREC) concurs
with the Selected Remedy for OU2 (Appendix E).

Assessment of the Site

The Selected Remedy in this ROD for interim action is necessary to protect public health or
welfare or the environment from actual or threatened releases of hazardous substances,
pollutants, or contaminants into the environment.

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Description of the Selected Remedy

The Selected Remedy for 0U2 addresses exposure to current and future residents to
groundwater containing unacceptable levels of Site-related contamination.

The contamination at the Site consists of heavy metals (including cobalt, hexavalent chromium,
and lead) and perfluoroalkyl/polyfluoroalkyl substances (PFAS) in groundwater. Groundwater is
the sole drinking water source for both public and domestic potable water in Blades and the
surrounding area. Residences within the town limits of Blades are connected to the public
water supply, which treats groundwater prior to distribution; however, residences located
beyond town limits to the southwest rely on domestic groundwater wells for potable water.
The area subject to this Selected Remedy are the residences located south and southwest,
outside of the town limits of Blades, bounded by Morgan Branch and the Nanticoke River as
depicted in Figure 2.

The Selected Remedy (Alternative 5) consists of the following components:

1.	Extending an existing public water line and connecting residential properties whose
private wells are currently impacted or potentially impacted by Site-related
contaminants.

2.	Implementing institutional controls such as local ordinances and/or groundwater
management zones to prevent the installation of new potable wells.

3.	Maintaining existing point-of-entry treatment systems (POETS) / point-of-use treatment
systems (POUTS) until connection to the public water line is complete.

The Selected Remedy will ensure long-term public protection from contaminated groundwater
until groundwater is restored to beneficial use under OU1.

Statutory Determinations

The Selected Remedy is protective of human health and the environment, complies with
Federal and State requirements that are legally applicable or relevant and appropriate to the
remedial action, is cost-effective, and utilizes permanent solutions to the maximum extent
practicable.

Because this Selected Remedy will result in hazardous substances remaining on-Site above
levels that allow for unlimited use and unrestricted exposure, a review will be conducted within
five years after commencement of the interim remedial action to ensure that the remedy
continues to provide adequate protection of human health and the environment. Such reviews
will be conducted a minimum of every five years thereafter, until EPA determines that
hazardous substances remaining at the Site do not prevent unlimited use and unrestricted
exposure at the Site.

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ROD Data Certification Checklist

The following information is included in the Decision Summary (Part 2) of this ROD. Additional
information can be found in the Administrative Record for the Site:

ROD CERTIFICATION CHECKLIST

Information

Location/Page Number

Contaminants of Concern (COCs) and respective
concentrations

Section VII, page 13

Baseline risk represented by COCs

Section VII, page 15

Cleanup levels established for COCs and the basis for
these levels

Section XI, page 27

Current and reasonably anticipated future land use
assumptions potential future beneficial uses of
groundwater used in the baseline risk assessment and
ROD

Section VI, page 11

Potential land and groundwater uses that will be
available at the Site as a result of the Selected Remedy

Section VI, page 11

Estimated capital, annual Operations & Maintenance
(O&M), and total present worth costs, discount rate, and
the number of years over which the remedy cost
estimates are projected

Section X, page 26

Key factors that led to selecting the remedy

Section XI, page 26

Authorizing Signature

This ROD for interim action documents the Selected Remedy for OU2 of the Site. EPA selected
this interim remedial action with the concurrence of DNREC.

Digitally signed by PAUL

PAUL LEONARD LEONARD

Date: 2024.02.09 12:53:56 -05'00'

Paul Leonard, Director

Superfund and Emergency Management Division

EPA Region 3

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INTERIM RECORD OF DECISION
BLADES GROUNDWATER SUPERFUND SITE
OPERABLE UNIT 2

2. DECISION SUMMARY

I. SITE NAME, LOCATION, AND DESCRIPTION

The Site is located within the Town of Blades, Sussex County, Delaware. The Site is
approximately 0.5 square miles, lying primarily between the Nanticoke River, Morgan Branch,
and Route 13 (See Figure 1). The Site was finalized on the National Priorities List (NPL) on
September 3, 2020. The National Superfund Database Identification Number for this Site is
DEN000304203. Contaminants commonly related to plating operations including metals and
per- and polyfluoroalkyl substances (PFAS) have been detected in residential drinking water
downgradient of the Site. EPA Region 3 is the lead agency for the Site, and DNREC is the
support agency.

II. SITE HISTORY AND ENFORCEMENT ACTIVITIES

There are two likely source areas of contamination related to this Site located in the Town of
Blades: Procino Plating (now known as Procino Enterprises), an active metal plating facility, and
the former Peninsula Plating facility, which is currently vacant land. The locations of Procino
Plating and former Peninsula Plating are shown in Figure 2. Below is a brief overview of the
operational history and environmental investigations conducted at both facilities, prior to the
Site being listed on the NPL. Additional information regarding these investigations can be found
in Sections 2.2 and 2.3 of the June 2019 Final Site Inspection (SI) Report. Investigations prior to
2018 did not include the collection or analysis of PFAS.

Procino Plating

Procino Plating is an active plating facility that began operations in Blades in 1985, performing
ornamental/decorative plating with copper, nickel, and chromium (See Figure 2). From 1994-
2002, Procino Plating received a series of Notices of Violation (NOVs) from DNREC and EPA
citing labeling, training and operational deficiencies related to handling of hazardous waste.
Procino Plating responded with notification letters stating that the deficiencies had been
corrected. None of the NOVs cited spillage, discharges, or releases of hazardous wastes. In
December 2007 and February 2008, DNREC and EPA conducted inspections, collected samples,
and interviewed employees at the Procino Plating. These inspections coincided with the 2007
discontinuation of plating operations in the second building when equipment was being
dismantled to create rental space. Procino Plating was issued an NOV pursuant to the Resource
Conservation and Recovery Act (RCRA). The operational and regulatory histories of the Procino
Plating facility led to DNREC, in cooperation with EPA, conducting a preliminary assessment (PA)

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at Procino Plating in 2010 due to chemical use, primarily metals, and the potential impact to soil
and groundwater.

During the 2010 PA, photographs were taken that showed the presence of Atotech Fumetrol®
140. Fumetrol is used as a mist suppressant to control the emission of chromium mists created
during the plating process. Perfluorooctane sulfonic acid (PFOS) is an active ingredient within
Fumetrol 140. PFOS was not identified or investigated as a contaminant of concern in 2010
since there was not as much toxicity data or analytical methods available as there are now. As a
result of the PA, a site investigation was recommended due to chemical use and the potential
to impact soil and groundwater. DNREC performed the SI activities in 2010 and 2011.

The SI included sampling any registered/permitted private water supply wells within the Town
of Blades limits. Water samples were collected from outdoor spigots of residential homes with
registered and accessible private wells where access was granted. Twelve private water supply
wells surrounding the Procino Plating facility were sampled. Soil and groundwater samples
were collected and analyzed for volatile organic compounds (VOCs), semivolatile organic
compounds (SVOCs), polychlorinated biphenyls (PCBs), pesticides, and for total and dissolved
target analyte list (TAL) inorganics on the Procino Plating property. Based on the results, DNREC
recommended further investigation. Procino Plating entered into a Voluntary Cleanup Program
agreement with DNREC in 2011 to complete the investigation.

From 2012 to 2015, Procino Plating's contractor performed various remedial investigation (Rl)
activities to characterize subsurface stratigraphy, determine groundwater elevations and flow
direction, determine the extent and magnitude of contamination, and assess potential human
health risks. Soil and groundwater at Procino Plating were not analyzed for PFAS during this
investigation.

In 2015, an interim removal action was completed by Procino Plating's contractor that
consisted of removing a portion of the facility's concrete slab floor, collecting soil samples for
the purpose of delineating chromium concentrations, and removing chromium impacted soil
with a mini excavator. Approximately 20 cubic yards of soil were removed from a 10-foot by 10-
foot area to depths of 6 to 8 feet below ground surface (bgs). A polyvinyl chloride (PVC) piping
system was also installed to facilitate potential future remedial injections.

In 2018, a chromic acid tank was overfilled with water and overflowed into a secondary
containment and crawlspace beneath the building. The total volume of solution spilled was
unknown, but 600 gallons were captured in the secondary containment. Procino Plating's
contractor removed the impacted soil for off-site disposal.

Peninsula Plating

The former Peninsula Plating facility was located within the former Blades Commercial Complex
at the intersection of Market Street and River Road (See Figure 2). Peninsula Plating operated
from 1992 to 1995 conducting brass, copper, and chrome plating operations. In 1995 the

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DNREC Hazardous Waste Management Branch conducted a site visit at the Peninsula Plating
facility. DNREC noted the presence of plating process chemicals, including nickel sulfate, sulfuric
acid, chromic acid, hexavalent chromium, hydrofluoric acid, nickel chloride, copper cyanide,
copper sulfate, zinc cyanide, and cadmium fluoroborate. Peninsula Plating closed shortly
thereafter, following a history of noncompliance with industrial waste discharge permits and
Emergency Planning and Community-Right-to-Know Act (EPCRA) requirements.

DNREC's Emergency Response and Enforcement Branches informed EPA Region 3 that the
former plating building contained numerous vats, tanks, drums, and containers of hazardous
materials. EPA conducted a CERCLA Removal Action at the abandoned Peninsula Plating facility
in mid to late 1995. The removal action included the removal of 78 55-gallon drums of
hazardous waste and 30 cubic yards of hazardous solids, including flammable and corrosive
liquids, oxidizers, and liquids contaminated with cadmium and chromium. DNREC performed an
SI at Peninsula Plating in 1999. Samples collected during the SI included soil and groundwater
samples from three on-site monitoring wells and one public supply well. With the exception of
the concentrations of arsenic, inorganics were not detected in the soil samples at
concentrations exceeding EPA or DNREC standards. Chromium was detected in three soil
samples at concentrations ranging from 2.4 mg/kg to 9.4 mg/kg. Organic analysis of soil
samples indicated several polycyclic aromatic hydrocarbons (PAHs) at concentrations exceeding
EPA and DNREC standards. Analysis of groundwater samples indicated concentrations of
aluminum, iron, and manganese in the on-site monitoring wells at concentrations above DNREC
regulatory standards and/or EPA maximum contaminant levels (MCLs). Chromium was not
detected in the collected groundwater samples. Organic constituents were not detected in
groundwater at concentrations exceeding the EPA or DNREC standards.

Based on the Procino and Peninsula facilities' operational and regulatory histories, previous
investigations, and the advancement of PFAS testing, EPA and DNREC furthered their
investigations. In 2018, EPA, in coordination with DNREC, conducted a site-wide investigation
(2018 SI) to further define the extent of contamination, assess the relative threat posed to
human health and the environment, and determine the need for additional action under
CERCLA.

Public Supply Well Sampling

All residences within the corporate limits of the Town of Blades are connected to the municipal
water supply. The Town of Blades maintains three municipal water supply wells. In February
2018, based on information pertaining to the use of PFAS at metal plating facilities and
potential hazards associated with consumption of PFAS, DNREC, in consultation with EPA,
collected samples from the Town of Blades' municipal supply wells to analyze for PFAS. Results
indicated each of the three public supply wells had a summed total concentration of
perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) ranging from 96.2 ppt
to 187.1 ppt,1 which was greater than the combined health advisory level (HAL) of 70 parts per

1 In 2016 EPA released a HAL for combined PFOA and PFOS at 70 ppt. At the time of this sampling, the HAL of 70
ppt was the level DNREC was acting upon. On June 15, 2022, EPA issued interim updated drinking water health
advisories for PFOA at 0.004 ppt and PFOS at 0.02 ppt that superseded those EPA issued in 2016.

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trillion (ppt). As a result of the HAL exceedance, DNREC and Delaware Department of Health
(DPH) began distributing alternative water to Blades' residents as a precautionary measure. On
February 19, 2018, DNREC funded and installed a carbon filtration system on the Blades water
supply system. On February 28, 2018, DNREC and DPH announced that a follow-up sampling of
the treated Blades water supply, in conjunction with the carbon filtration system, showed non-
detect levels for PFAS. The public water system continues to be sampled on a reoccurring basis
to ensure protectiveness and the sample results continue to be below standards.

Residential Well Sampling

Residences outside of the Blades town limits are served by private domestic wells. In February,
March, and April of 2018, EPA collected domestic well water samples from 54 locations for
PFAS analysis. PFAS concentrations exceeded the combined HAL of 70 ppt in effect at the time
for PFOS and PFOA concentrations in seven of the domestic wells located southwest of Blades.
PFOS was the main contaminant detected with concentrations up to 350 ppt.

Subsequently during 2018, DNREC provided drinking water filters to all residents with domestic
wells impacted with PFOA/PFOS concentrations above 52.5 ppt (75% of the HAL in effect in
2018). DNREC provided the filters to eight residences and has continued to provide
replacement filters as needed.

On September 3, 2020, EPA added the Site to the NPL based on the conclusions of the 2018 SI
that identified chromium, copper, nickel, zinc, and cyanide above EPA health-based screening
levels and/or MCLs in groundwater and soil. Additionally, PFAS, specifically PFOA and PFOS,
were detected above EPA's 2016 HAL in groundwater.

Remedial Investigation/Removal Action

After listing on the NPL, EPA began Rl activities to define the nature and extent of
contamination. EPA conducted routine sampling of the public water supply to ensure the
treated water continued to meet federal and state drinking water standards.2 Additionally, EPA
contacted 97 households through mailings and door-to-door visits, requesting permission to
sample residents' domestic well water for a full suite of analysis, including PFAS compounds.

A total of 55 residents agreed to sampling which included residences that were previously
sampled and residences that had not been previously sampled during the 2018 residential
sampling event. Samples were collected from outdoor spigots or indoor taps in the event
outdoor spigots were not available. Figure 3 depicts the approximate boundaries of the
residential sampling effort. Based upon results, several constituents exceeded tapwater
Regional Screening Levels (RSLs). Notably, hexavalent chromium, cobalt, lead, and PFOS
exceeded either the MCL pursuant to the Safe Drinking Water Act, or the Removal
Management Level (RML). RMLs are used to support the decision for EPA to undertake a

2 As of December 2023, the Town of Blades will be responsible for conducting routine public water supply
sampling.

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removal action under CERCLA. Based on the RML and MCL exceedances, EPA conducted a
removal action at 12 residences whose owners granted access. EPA issued a removal action
memorandum in March 2022 to address the hexavalent chromium, cobalt, and lead that was
found to exceed action levels in well water of nine households. An addendum to EPA's removal
action memorandum was issued in August 2022 to add additional residences where lead
exceeded the MCL and cobalt exceeded the RML (two additional households) after resampling
had occurred, and additionally to address PFOS after EPA's RMLs were updated to be more
stringent3 (two additional households). At these locations, there were residential wells where
more than one contaminant was found to be above its respective RML or MCL at a given
location. The removal action was conducted to address exceedances for multiple contaminants
when present.

At these 12 residences, either Point-of-Entry Treatment Systems (POETS) / Point-of-Use
Treatment Systems (POUTS) were installed based on space availability and access to plumbing.
POETS were installed in residences where there was enough space to accommodate the system
(e.g., garage, basement, or closet) and the system could be connected to the well plumbing that
would route to the entire household. POUTS were installed at locations where POETS were not
feasible. EPA installed POUTS in bathroom and kitchen sinks, where a resident is most likely to
ingest water. A total of 2 POETS were installed at 2 residences, and a total of 21 POUTS were
installed at 10 residences.

In 2021, Delaware passed House Bill 8, which required DNREC and DPH to work cooperatively to
issue MCLs for PFOA and PFOS. In anticipation, DPH issued an Implementation Plan proposing
MCLs for PFOA at 21 ppt, 14 ppt for PFOS and 17 ppt for the sum of both PFOS and PFOA. 4
DNREC currently provides filters as a preventive measure to residences (where the resident
allows such assistance) where domestic well concentrations are equal to or greater than 4 ppt
PFOA or PFOS.

Due to the contamination found in domestic well water, EPA created OU2 for an interim action
to provide a consistent source of treated or alternative water to residences whose well water is
impacted or likely to become impacted. EPA is continuing the Site-wide Rl under OU1 to define
the nature and extent of contamination (and to identify any other potential source areas) and
will subsequently propose and select a final remedial action to address Site-wide
contamination. The area subject to this interim action is outside of the Town of Blades, to the
south and southwest, bounded by Morgan Branch and the Nanticoke River.

In August of 2022, EPA finalized the Rl Report, including the Human Health Risk Assessment
(HHRA), for OU2 to summarize the residential sampling effort and to calculate unacceptable risk
posed by contaminant levels from the results. Additional information on the HHRA can be

3 The RML for hexavalent chromium is 3.5 parts per billion (ppb); the RML for cobalt is 18 ppb; the MCL for lead is
15 ppb; the RML for PFOS is 120 ppt.

4 This link provides the Delaware Division of Public Health's PFOA and PFOS MCL Implementation Plan that DNREC
uses as a proactive measure to provide water filters to residences.
https://www.dhss.delaware.gov/dhss/dph/hsp/files/MCLimplementationPlanPFAS.pdf.

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found under the Summary of Site Risks section of this ROD and Appendix C of the August 2022
Rl Report for Operable Unit 2. Because the HHRA indicated that contaminants in well water
posed an unacceptable risk to some residents, EPA identified and evaluated various remedial
alternatives to address this risk in a February 2023 Feasibility Study (FS). The remedial
alternatives presented in the FS were evaluated by EPA and a Preferred Alternative was
proposed for public comment in the Proposed Remedial Action Plan (Proposed Plan) in June
2023.

III.	HIGHLIGHTS OF COMMUNITY PARTICIPATION

Pursuant to Section 113(k)(2)(B) of CERCLA, 42 U.S.C. § 113(k)(2)(B), the Rl and FS reports, the
Proposed Plan, and other documents relating to OU2 were released to the public for comment
on June 29, 2023. These documents were made available to the public online at
https://semspub.epa.gov/src/collection/03/AR67374. in the EPA Administrative Records Room
at EPA's Region 3 office in Philadelphia, and in the Seaford District Library in Seaford, Delaware.
The notice of availability of these documents was published in the Seaford Star and a fact sheet
detailing the Proposed Plan was mailed to local citizens on June 29, 2023.

A public comment period was held from June 29, 2023, until July 28, 2023. EPA held a public
meeting on July 20, 2023, at the Blades Fire Company, located at 200 E. 5th Street, Blades,
Delaware 19973. During the public meeting, EPA gave a formal presentation on EPA's Proposed
Plan, followed by a "Question and Answer" session where representatives from EPA answered
questions regarding the Site and the Proposed Plan. All significant comments related to OU2 are
provided in the Responsiveness Summary. No written comments were received on the
Proposed Plan. All comments provided in the Responsiveness Summary are from the July 20,
2023, public meeting. A transcript of the public meeting is available in the Administrative
Record.

IV.	SCOPE OF THE SELECTED REMEDY

During the Rl, contaminants commonly related to plating operations including metals (cobalt,
lead, and hexavalent chromium) and PFAS have been detected in residential drinking water
downgradient of the Site. A removal action was conducted in an expedited manner by EPA to
address the immediate risk posed by the contamination. The OU2 interim remedial action set
forth in this ROD provides a permanent remedy to prevent the exposure to current and future
residents to groundwater containing unacceptable levels of Site-related COCs.

This OU2 interim remedial action will be consistent with the final remedial action for the
restoration of groundwater to beneficial use at the Site (OU1). The final remedial action will be
the subject of a future proposed plan and ROD following completion of the OU1 RI/FS, which
addresses all contaminated media at the Site.

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V. SITE CHARACTERISTICS

A. Physical Setting

The Town of Blades is located along the southern bank of the Nanticoke River, a tributary of the
Chesapeake Bay, and north of Morgan Branch, which flows west to converge with the
Nanticoke River, as seen on Figure 1. The Site is located in the Coastal Plain Physiographic
Province, which consists of a seaward-dipping wedge of unconsolidated and semi-consolidated
sediments.

B. Geology

Overburden Composition

In general, the Site is underlain by the Nanticoke River Group deposits, which consist of the
Turtle Branch and Kent Isle formations and are related to rise and high stand of sea level; the
formation can consist of beach, tidal flat, open estuary, marsh, swamp, and fluvial deposits.
These deposits underlie terraces that flank the margins of the present Nanticoke River and its
tributaries.

Hydrogeology

The surficial aquifer (Columbia aquifer) extends over a large part of the Delmarva Peninsula.
The aquifer consists of unconsolidated sand and gravel and includes the Nanticoke River Group
deposits where present. The aquifer contains water predominantly in the unconfined
conditions of the sand and gravel beds, but clay beds can create locally semi-confined
conditions. Within the vicinity of Blades, the fine-grained beds of the Manokin Formation are at
the base of the Columbia aquifer. Therefore, the aquifer acts as both an unconfined and semi-
confined aquifer with a saturated thickness ranging from 30 to 100 feet.

The deep aquifer (Choptank aquifer) consists of multiple fining-upward sequences of fine to
coarse sand and shelly and gravelly sand, that grade into sandy clayey shelly silt and is isolated
from the contaminant plume by sub-surface confining units, notably the St. Mary's formation.

Groundwater is encountered at shallow depths, between 9 and 12 feet below ground surface
(bgs). Groundwater flow across the Site has both horizontal and vertical flow components.
Groundwater in the Columbia aquifer exists under the water table (unconfined) conditions.
Based on groundwater elevations collected during the 2018 SI, it was inferred that groundwater
flow at the Procino facility was generally north to south, towards Morgan Branch. However, a
complete description of the horizontal and vertical groundwater flow characteristics and the

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influence of pumping on groundwater and surface water will continue to be defined as part of
theOUl Rl.

C. Nature and Extent of Contamination

Past investigations and assessments have identified the presence of organic, inorganic, and
PFAS-containing materials that were stored and used at the former Peninsula and Procino
Plating facilities. Therefore, these properties are probable source areas for metals and PFAS
found in environmental media. These contaminants have been identified in drinking water
samples from residential wells close to the Site and downgradient from these facilities. During
the continued OU1 Rl, other potential source areas will be investigated, and the nature and
extent of contamination will be more fully defined.

The most significant pathway for contaminant migration is from uncontrolled releases at
historical and current source areas that infiltrate the soil column and migrate downward into
groundwater. Once in the groundwater, contaminants migrate via horizontal and vertical
pathways through the saturated zone of the Columbia aquifer. The operation of municipal and
domestic wells may draw contaminants to well intakes. Surface water bodies (Nanticoke River
and Morgan Branch) also likely influence the local flow of groundwater in and around the Site.

To date, public, domestic, and monitoring well samples confirm the presence of PFAS in
groundwater. Furthermore, elevated concentrations of metals, including cobalt, hexavalent
chromium, and lead were detected in domestic wells.

D. National Historical Preservation Act

EPA has initiated National Historic Preservation Act (NHPA) consultation with stakeholders
including Delaware State Historic Preservation Office (DESHPO), DNREC, Delaware Nation, and
Delaware Tribe of Indians. These consultation efforts led to the consummation of
"Programmatic Agreement Among the Environmental Protection Agency, and the Delaware
State Historic Preservation Office Regarding Implementation of Interim Remedial Action for
Blades Groundwater Superfund Site, Operable Unit 2 Blades, Sussex County, DelawareThis
document was made effective on November 6, 2023. This document sets forth procedures to
determine if historical properties are present and, if historical properties are present,
procedures for avoidance or minimization of adverse impacts on historic properties that will be
implemented as part of the interim remedial action for the Site and can be found in the
Administrative Record.

VI. CURRENT AND POTENTIAL FUTURE LAND AND RESOURCE USES

The current and reasonably anticipated future land use in the Town of Blades and surrounding
areas is residential land use, however light commercial and industrial facilities exist in and

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around the Town of Blades. Groundwater is the sole drinking water source for both public and
domestic potable water in the Town and the surrounding area. It is expected future land and
groundwater uses will remain the same. The land use controls associated with the Selected
Remedy (see selected ICs) will be consistent with current and any future land and groundwater
use.

VII. SUMMARY OF SITE RISKS

During the OU2 Rl, an HHRA was conducted to determine the current and potential future
effects of contaminated drinking water on human health in the absence of any cleanup actions
at the Site. A baseline risk assessment (before any cleanup) provides the basis for taking a
remedial action and indicates the exposure pathway(s) that need to be addressed by the
remedial action. This section summarizes the results of the HHRA at the Site.

For more detailed human health information, please refer to the August 2022 Blades
Groundwater HHRA available in the Administrative Record for the Site. Human health risk
summary tables from the HHRA are included as Appendix C to this ROD.

WHAT IS RISK AND HOW IS IT CALCULATED?

A Superfund human health risk assessment estimates the baseline risk. The baseline risk is an
estimate of the likelihood of health problems occurring if no cleanup action were taken at a site. To
estimate the baseline risk at a Superfund site, EPA undertakes a four-step process:

Step 1: Analyze Contamination

Step 2: Estimate Exposure

Step 3: Assess Potential Health Dangers

Step 4: Characterize Site Risk

In Step 1, EPA looks at the concentrations of contaminants found at a site as well as past scientific
studies on the effects these contaminants have had on people (or animals, when human studies are
unavailable). Comparisons between site-specific concentrations and concentrations reported in past
studies help EPA to determine which contaminants are most likely to pose the greatest threat to
human health.

In Step 2, EPA considers the different ways that people might be exposed to the contaminants
identified in Step 1, the concentrations that people might be exposed to, and the potential frequency
and duration of exposure. Using this information, EPA calculates a "reasonable maximum exposure"
scenario, which portrays the highest level of human exposure that could reasonably be expected to
occur.

In Step 3, EPA uses the information from Step 2 combined with information on the toxicity of each
chemical to assess potential risks. EPA considers two types of risk: cancer and non-cancer risk. The
likelihood of any kind of cancer resulting from a Superfund site is generally expressed as an upper
bound probability; for example, a "1 in 10,000 chance." In other words, for every 10,000 people that

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could be exposed, one extra instance of cancer may occur as a result of exposure to site
contaminants. An extra cancer case means that one more person could get cancer than would
normally be expected to from all other causes. For non-cancer health effects, EPA calculates a
"hazard index." The key concept here is that a "threshold level" (measured as a HI of equal to or less
than 1) exists below which non-cancer health effects are no longer predicted.

In Step 4, EPA determines whether site risks are great enough to cause health problems for people at
or near the Superfund site. The results of the three previous steps are combined, evaluated, and
summarized. EPA adds up the potential risks from the individual contaminants and exposure
pathways and calculates a total site risk. Generally, cancer risks between 10"4 and 10 s, and a non-
cancer HI of 1 or less are considered acceptable for EPA Superfund sites.

A. Human Health Risk Assessment Summary

The HHRA was conducted for 13 residential locations where groundwater concentrations
exceeded EPA and/or DNREC action levels to characterize and quantify the current and
potential future human health risks that would occur if no remedial action were taken to
address contaminated drinking water at the Site. The HHRA identifies the potential exposure
pathways in which people may be exposed to Site contaminants, the toxicity of the
contaminants present, and the potential for carcinogenic and non-carcinogenic effects to occur
from exposure to the contaminants.

Identification of Contaminants of Concern

The selection of contaminants of potential concern (COPCs) is a risk-based screening step to
identify chemicals that should be included in the quantitative risk assessment. The selection of
COPCs was based on information regarding chemical substances found at the Site including
chemical-specific concentrations, occurrence, distribution, and toxicity. COPCs include only
those chemicals with positive detections and are limited to those chemicals that exceed the
selection criterion. Screening levels based on residential exposure assumptions were used for
this HHRA as a health-protective screening tool to be protective of all potential current and
future Site uses. The COCs identified in the HHRA include cobalt, hexavalent chromium, lead,
PFOA, and PFOS.

Risk assessments are conducted using an exposure point concentration (EPC) for each COPC.
The EPC represents an estimated concentration to which a receptor is assumed to be
continuously exposed while in contact with an environmental medium. Consistent with EPA's
Supplemental Guidance to RAGS: Calculating the Concentration Term, a conservative estimate
of the mean concentration is used as the EPC. The EPC is generally defined as the 95 percent
upper confidence limit (UCL) on the mean and is calculated using EPA's ProUCL 5.1 software.

EPCs used in the risk assessment are presented in Appendix C.

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Exposure Assessment

The exposure assessment portion of the risk assessment defines and evaluates the type and
magnitude of human exposure to the chemicals present at or migrating from a site. Based on
current and potential future land use at the site, residents (child/adult) were identified as
potential receptors. Groundwater within the study area is used as a drinking water source and
several surveys have been conducted to identify residential wells within the study area that
may be impacted by the groundwater contaminant plume.

Exposure to lead was assessed using the following models:

• The latest version of EPA's Integrated Exposure Uptake Biokinetic (IEUBK) Model for
lead (version 2). This model is typically used to evaluate lead exposure assuming a
residential land use scenario.

• EPA's Adult Lead Methodology (2003b and 2017). This methodology is typically used to
evaluate lead exposure assuming a non-residential land use scenario.

The IEUBK Model for lead is designed to estimate blood levels of lead in children (under 7 years
of age) based on either default or site-specific input values for air, drinking water, diet, dust,
and soil exposure. Studies indicate that infants and young children are extremely susceptible to
adverse effects from exposure to lead. Considerable behavioral and developmental
impairments have been noted in children with elevated blood-lead levels. Historically blood-
lead levels greater than 10 micrograms per deciliter (|ag/dL) were considered to be a "concern."
Current scientific literature on lead toxicity indicates that adverse health effects are associated
with blood-lead (PbB) levels below the long-held target of 10 |ag/dL. Specifically, evidence exists
of clear cognitive declines in young children with PbB levels between 2 and 8 |ag/dL (as
referenced in the December 2016 EPA Office of Land and Emergency Management [OLEM]
Memo). Therefore, a value of 5 |ag/dL was used as the acceptable blood lead level in this HHRA.

The exposure factors used to estimate intake for residents (child/adult) are presented and
defined in Appendix C.

Toxicity Assessment

The toxicity assessment for the COPCs examines information concerning the potential human
health effects of exposure to COPCs. The goal of the toxicity assessment is to provide, for each
COPC, a quantitative estimate of the relationship between the magnitude and type of exposure
and the severity or probability of human health effects.

The toxicity values applied in the HHRA can be found in Appendix C.

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Risk Characterization

EPA has set a target risk range of 10~4 to 10~6 for a lifetime excess carcinogenic risk. An excess
lifetime cancer risk means the acceptable risk to an individual of developing cancer from
exposure over a lifetime to carcinogens at a site is between 10,000 to 1 (10~4) and 1,000,000 to
1 (10~6). For non-carcinogenic contaminants, EPA sets a target Hazard Index (HI) of no greater
than 1. The hazard quotient (HQ) measures the risk posed by each exposure pathway (i.e.,
inhalation, ingestion, and dermal contact) for a single non-carcinogenic contaminant at a site,
while the HI is the sum of all of the HQ values for the respective receptor (e.g., child or adult
resident).

The COCs identified in the HHRA include cobalt, hexavalent chromium, lead, PFOA, and PFOS.

Of the 13 select locations, the HHRA determined that there is unacceptable risk, exceedance of
regulatory thresholds (carcinogenic risk 1E-4, non-carcinogenic HI of 1), from drinking water to
child and adult receptors, as summarized in Table 1 below.

Table 1: Risk Findings

Risk Findings

Number of Locations

Highest Threshold
Exceedances

No unacceptable risk

None

--

Cobalt in drinking water-
unacceptable risk to child and
adult receptors

9 locations

Non-carcinogenic HI of 5

Lead in drinking water -
unacceptable risk to child
receptor

3 locations

Greater than 5% of children
exposed exceed a blood lead
level of 5 |ag/dL

PFOA and PFOS in drinking
water - unacceptable risk to
child and adult receptors

4 locations child and adult
3 locations child only

Non-carcinogenic HI of 6

Hexavalent Chromium in
drinking water - risk to the
lifetime receptor

1 location

Carcinogenic risk of 2E-04

A summary of the carcinogenic and non-carcinogenic risks are presented in Appendix C.

15

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Risk from Lead

Residential exposures to lead in soil and groundwater were evaluated using EPA's Integrated
Exposure Uptake Biokinetic (IEUBK) lead model. The results of the IEUBK model indicate that
risks for current child residents exposed to lead in surface soil do not exceed the EPA goal of no
more than 5% of children exceeding a 5 microgram per deciliter (|ag/dL) blood-lead level.
However, the IEUBK model also indicates that risks to future child residents exposed to lead in
both groundwater and surface/subsurface soil exceed the EPA goal; lead in groundwater was
responsible for the exceedance of the benchmark for residential exposures to lead.

B. Summary of Ecological Risk Assessment

A Screening Level Ecological Risk Assessment (SLERA) was not conducted as part of the OU2 Rl
activities because OU2 specifically addresses the contamination found in residential drinking
water. Ecological risk will be assessed for the Site in a future Rl and ROD for OU1.

C. Summary of Site Risks

In summary, the HHRA for the Site demonstrates the presence of unacceptable risk to human
health, and that remedial actions are necessary to reduce the risks to within or below EPA's
acceptable risk range. EPA has identified the COCs that pose the greatest potential
unacceptable risk to human health and the environment at the Site. Therefore, EPA has
determined that the Selected Remedy for this Interim ROD is necessary to protect public health
or welfare or the environment from actual or threatened releases of hazardous substances into
the environment.

VIII. REMEDIAL ACTION OBJECTIVES

Remedial Action Objectives (RAOs) are specific goals developed to address the Site COCs and
exposure pathways to protect human health and the environment. These objectives are based
on available information and standards, such as applicable or relevant and appropriate
requirements (ARARs), to-be-considered (TBC) guidance, and Site-specific risk-based levels.

The RAO established for this interim remedial action is to:

• Prevent current and future residential exposure to groundwater containing
unacceptable levels of Site-related COCs.

EPA guidance states that "an interim action is limited in scope and only addresses areas/media
that also will be addressed by a final site/operable unit ROD. Reasons for taking an interim
action could include to:

• Take quick action to protect human health and the environment from an imminent
threat in the short term, while a final remedial solution is being developed; or

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• Institute temporary measures to stabilize the Site or operable unit and/or prevent
further migration of contaminants or further environmental degradation."5

This RAO is designed to support a final remedial action which will comply with CERCLA
requirements to clean up contaminants in groundwater and restore the groundwater to
beneficial use. Therefore, the RAO reflects the limited scope of an interim action. By preventing
human exposure to contaminated groundwater, the interim action will reduce Site risks by
ensuring the public is not exposed or potentially exposed to contaminants in groundwater prior
to the restoration of groundwater.

IX. SUMMARY OF REMEDIAL ACTION ALTERNATIVES

The Superfund law (CERCLA) requires that any remedy selected to address contamination at a
site must be protective of human health and the environment, cost-effective, in compliance
with promulgated standards or requirements that are determined to be ARARs, and consistent
with the NCP. The five Remedial Alternatives, as shown in Table 2, were evaluated to meet the
RAO for this interim remedial action.

Table 2: Remedial Alternatives Evaluated

Alternative

Description

No Action

Bottled Water

Point-of-entry Treatment Systems (POETS) / Point-of-use Treatment Systems
(POUTS)

Install Deeper Drinking Water Wells

Connection to Public Water Line and Institutional Controls (ICs)

Alternative 1: No Action

Consideration of this alternative is required by the NCP at 40 C.F.R. § 300.430(e)(6). Under
Alternative 1, no additional remedial action would be taken at the Site. The "no action"
alternative serves as a basis against which each of the other proposed remedial alternatives can
be compared. Under this alternative, the Site would remain in its present condition. Current
and future residents would remain exposed to Site-related contaminants in residential drinking
water wells. Under this alternative, the existing POETS and POUTS that have been provided by
EPA's removal program would no longer be maintained by EPA or DNREC and would be
properly removed.

Alternative 2: Bottled Water

Under this alternative, bottled water would be delivered to all impacted or potentially impacted
residences on a reoccurring basis and EPA would fund the delivery costs. This alternative would

5 A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision
Documents" (Office of Solid Waste and Emergency Response) (July 1999), at p. 8-2.

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be in effect until a future groundwater remediation project achieves cleanup goals and supplied
water is no longer necessary. Typically, a duration of up to 30 years is assumed for groundwater
remedies for the purposes of cost calculation.

Under this alternative, an initial bottle supply system/dispenser would be put in place in each
residence with large volume (e.g., 5-gallon) bottles. Reoccurring deliveries would provide water
as needed for each impacted or potentially impacted residence. Existing private wells would
remain in place for non-ingestion uses (e.g., bathing and irrigation) and monitored to evaluate
any changes in groundwater conditions.

Under this alternative, the existing POETS and POUTS that are provided by the EPA removal
program would be maintained by EPA until implementation of the alternative, at which point,
EPA would no longer maintain the systems.

Alternative 3: Point-of-entry Treatment Systems (POETS) / Point-of-use Treatment Systems
(POUTS)

Under this alternative, POETS/ POUTS would be installed at all impacted or potentially impacted
residences, and EPA would fund the cost of installation of the system. POETS are installed to
filter and treat all water entering the household. POUTS treat only the water intended for direct
consumption (drinking and cooking) and are typically installed at a single tap or limited number
of taps. This alternative would be in effect until a future groundwater remediation project
achieves cleanup goals and the treatment systems are no longer necessary. Typically, a
duration of up to 30 years is assumed for groundwater remedies for the purposes of cost
calculation.

Each residence would be evaluated for which type of treatment system would be most
appropriate, with the preferred option being POET which treats all water entering the home.
POETS/POUTS have already been installed at some residences, but they may not include all
processes necessary to remove all COCs. Residences where systems do not meet the
requirements to remove all COCs, to achieve the RAO, would require system upgrades.
Currently installed systems depended on the amount of space available (wall space/closet
space/garage/basement for POET, or POUT installed on bathroom and kitchen faucets when
space does not allow for POET). Filter/media replacement (various timing depending on the
filter/media) are required for both types of systems.

Monitoring of treated water would be performed to evaluate remedy protectiveness/success
and is assumed to be performed annually for 30 years; however, the frequency and duration of
monitoring could differ if this alternative were selected as the interim remedy.

Alternative 4: Install Deeper Water Wells

Under this alternative, new wells targeting groundwater below the contaminant plume would
be installed by EPA at each impacted or potentially impacted residence. The wells would be

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approximately 250 to 300 feet deep and screened in the Choptank aquifer, which is isolated
from the contaminant plume by the sub-surface confining geologic unit in the St. Mary's
formation.

Prior to installing individual private wells in the deeper aquifer, a pump test and sampling
would be performed to confirm that the aquifer could produce the necessary amount of water
and it is unimpacted by contaminants from the Site.

Each residence would have a new well installed and the existing wells would be abandoned. If
needed for residences near wetland resource areas, erosion control measures (i.e., silt fences)
would be installed prior to well installation. Evaluation of the best placement (both location and
depth) would be determined during pre-design and design efforts.

Monitoring of well water would be performed to evaluate remedy protectiveness and is
assumed to be performed annually for 30 years; however, the frequency and duration of
monitoring could differ if this alternative were selected as the interim remedy.

Under this alternative, the existing POETS and POUTS that are provided by the EPA removal
program would be maintained by EPA until implementation of the alternative, at which point,
EPA would no longer maintain the systems.

Alternative 5: Connection to Public Water Line and ICs

This alternative involves extending a public water line into the impacted area and connecting
impacted or potentially impacted residences to the public water line distribution system. Under
Alternative 5, upgrades or expansions to the public water system maintained by the Town of
Blades would be determined during the design phase in consultation with the state and the
town.

Capital costs would be funded by EPA, with monthly water use being paid by residents. This
alternative requires the agreement of affected residents to connect to the Blades' public water
system. Residents who elect to be connected would have their existing drinking wells
completely disconnected from the house water system and either abandoned by EPA or
converted to non-potable use if the intended use does not pose unacceptable risk. Residents
who elect not to be connected would continue to use their private drinking wells and all
associated costs to make a future connection the public water supply would be at the
homeowner's expense.

Under this alternative, the existing POETS and POUTS that have been provided by the EPA
removal program would be maintained by EPA until implementation of the alternative, at which
time EPA would no longer maintain the systems.

This alternative would eliminate exposure to contaminated groundwater by providing an
alternate water supply and implementing institutional controls (ICs) such as local ordinances

19

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and/or groundwater management zones to prevent the installation of new potable wells and
proper abandonment/capping of existing wells.

X. COMPARATIVE ANALYSIS OF ALTERNATIVES

A. Criteria Used to Compare Cleanup Alternatives

The remedial alternatives have been evaluated against the nine decision criteria set forth in the
NCP, 40 C.F.R. § 300.430(e)(9)(iii) and listed in Table 3 below. These nine criteria are organized
into three categories: threshold criteria, primary balancing criteria, and modifying criteria.
Threshold criteria must be satisfied in order for an alternative to be eligible for selection.
Primary balancing criteria are used to weigh major trade-offs among alternatives. Modifying
criteria are formally taken into account after public comment has been received on the
Proposed Plan.

In the remedial decision-making process, EPA describes the relative performance of each
alternative against the evaluation criteria and notes how each alternative compares to the
other alternatives under consideration. A detailed analysis of alternatives can be found in the
FS, which is in the Administrative Record file for the Site.

Table 3: Evaluation Criteria for Superfund Remedial Alternatives

Threshold
Criteria

1. Overall Protection of Human Health and the Environment determines whether
an alternative can adequately protect human health and the environment by
eliminating, reducing, or controlling exposures to hazardous substances,
pollutants or contaminants to levels that do not pose an unacceptable risk.

2. Compliance with ARARs evaluates whether an alternative meets Federal and
more stringent State environmental laws or facility siting laws, or whether a waiver
is justified.

Primary Balancing Criteria

3. Long-term Effectiveness and Permanence considers the ability of an alternative
to maintain protection of human health and the environment over time.

4. Reduction of Toxicity, Mobility, or Volume of Contaminants through
Treatment evaluates an alternative's use of treatment to reduce the harmful
effects of principal contaminants, their ability to move in the environment, and
the amount of contamination present.

5. Short-term Effectiveness considers the length of time needed to implement an
alternative and the risks the alternative poses to workers, residents, and the
environment during implementation.

6. Implementability considers the technical and administrative feasibility of
implementing an alternative, including factors such as the relative availability of
goods and services.

7. Cost includes the estimated capital and annual operation and maintenance
costs, as well as present worth cost of an alternative. Present worth cost is the
total cost of an alternative over time in today's dollar value. Cost estimates are
expected to be accurate within a range of +50 to -30 percent.

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8. State/ Support Agency Acceptance considers whether the State agrees with
EPA's analyses and recommendations, as described in the Feasibility Study and
Proposed Plan.

9. Community Acceptance considers whether the local community agrees with
EPA's analyses and preferred alternative. Comments received on the Proposed
Plan are an important indicator of community acceptance.

B. Detailed Analysis of Proposed Remedial Alternatives

1. Overall Protection of Human Health and the Environment

Alternative 1 (No Action) does not provide adequate protection of human health and the
environment because it does not eliminate or control the current and future risks from
exposure to contaminated groundwater. The No Action alternative will not be discussed further
in the nine criteria analysis because it does not satisfy the threshold criterion of providing
overall protection to human health.

Alternative 2 (Bottled Drinking Water) is effective in reducing risks related to ingestion of
contaminated groundwater. As contaminated groundwater would still enter residences, the
reliability of the alternative depends on residents being diligent in drinking only the bottled
water. Assuming the resident complies with use of bottled water, this alternative would be
protective to human health because exposure via ingestion of contaminated groundwater
would be eliminated.

Alternative 3 (POETS/POUTS) is effective in reducing risks related to ingestion of contaminated
groundwater. While exposure pathways related to contaminated groundwater may still exist in
a residence, depending on the type of system (POET vs. POUT), proper usage and maintenance
would reduce ingestion risks. Similar to Alternative 2, assuming that the resident complies with
use of POETS/POUTS, this alternative is considered protective of human health.

Alternative 4 (Installing Deeper Drinking Water Wells) involves replacing existing residential
wells with wells screened in a deeper aquifer not hydraulically connected to the impacted
Columbia aquifer. Assuming the deeper aquifer is free from contaminants, this alternative is
considered protective of human health.

Alternative 5 (Connection to Public Water Line and ICs) would protect human health by
eliminating the need to use contaminated groundwater from private drinking water wells in the
impacted areas. Alternative 5 would provide a permanent, treated and monitored water supply
to the residences through connection to a public water system. Additionally, ICs would prevent
the installation of new potable wells until groundwater is restored to its designated beneficial
use.

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2. Compliance with ARARs

Section 121(d) of CERCLA, 42 U.S.C. § 9621(d), and the NCP at 40 C.F.R. § 300.430(f)(l)(ii)(B),
require that remedial actions at CERCLA sites at least attain legally applicable or relevant and
appropriate Federal and State requirements, standards of control, and other substantive
environmental protection requirements, criteria, or limitations promulgated under Federal or
State law, which are collectively referred to as "ARARs," unless such ARARs are waived under
Section 121(d)(4) of CERCLA, 42 U.S.C. § 9621(d)(4), and the NCP at 40 C.F.R. §
300.430(f)(l)(ii)(C).

"Applicable" requirements are those cleanup standards, standards of control, and other
substantive requirements, criteria, or limitations promulgated under Federal environmental or
State environmental or facility-siting laws that specifically address a hazardous substance,
pollutant, contaminant, remedial action, location, or other circumstance at a CERCLA site. Only
those State standards that are identified by a State in a timely manner and that are more
stringent than Federal requirements may be applicable.

"Relevant and appropriate" requirements are those cleanup standards, standards of control,
and other substantive requirements, criteria, or limitations promulgated under Federal
environmental or State environmental or facility-siting laws that, while not "applicable" to a
hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance
at a CERCLA site, address problems or situations sufficiently similar to those encountered at the
CERCLA site that their use is well-suited to the particular site. Only those State standards that
are identified by a State in a timely manner and that are more stringent than Federal
requirements may be relevant and appropriate.

EPA also considers to-be-considered materials (TBCs), along with ARARs. TBCs are non-
promulgated criteria, advisories, or guidance, issued by Federal or State government that are
not legally binding and do not have the status of potential ARARs. However, TBCs may be
considered during development of remedial alternatives. EPA may use TBCs in determining the
necessary level of cleanup for protection of human health or the environment when ARARs do
not exist for particular contaminants.

ARARs for remedial action alternatives can be classified into one of the following three
functional groups:

• Chemical-Specific: Health-risk-based numerical values or methodologies that establish
concentration or discharge limits for particular contaminants. Often, these ARARs are used
to determine the extent of site remediation. In general, chemical-specific requirements are
set for a single chemical or a closely related group of chemicals. Examples include MCLs,
promulgated under the Safe Drinking Water Act (SDWA). Potential Federal and more
stringent State chemical-specific ARARs and TBCs for the Preferred Alternative are identified
in Appendix B.

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•	Location-Specific: Requirements that restrict remedial actions based on the characteristics
of the Site or its immediate environment. Examples of these areas regulated under various
Federal laws include floodplains, and wetlands. Federal and more stringent State location-
specific ARARs and TBCs identified for the Preferred Alternative are presented in Appendix
B.

•	Action-Specific: Requirements that set controls or restrictions on the design,
implementation, and performance levels (including discharge limits) of activities related to
the management of hazardous substances, pollutants, or contaminants. These action-
specific requirements do not in themselves determine the remedial alternative; rather, they
indicate how a selected alternative must be achieved. Federal and more stringent State
action-specific ARARs and TBCs for the Preferred Alternative are identified in Appendix B.

The major ARARs for this interim action include:

•	National Primary Drinking Water Standards: 40 C.F.R. §§ 141.50, 141.61 and 141.62
establish health-based standards (i.e., Maximum Contaminant Level Goals (MCLGs) and
MCLs) for public drinking water.

•	Delaware Regulations Governing the Construction and Use of Wells: 7 Del. Admin. C.
§ 7301 contains requirements governing the location, design, installation, use,
modification, repair, and sealing of all wells and associated equipment as well as
requirements for public and private potable wells.

All alternatives analyzed in this remedial decision-making process would meet their respective
ARARs for Federal and State laws. Achievement of chemical-specific ARARs in groundwater
within the aquifer will be addressed in a future decision document that addresses the
restoration of groundwater.

3. Long-Term Effectiveness and Permanence

Alternative 2 (Bottled Water) does not permanently eliminate the exposure pathway to
contaminated groundwater. There will be some residual risk since contaminated groundwater
would still enter residences. The reliability of this alternative depends on residents being
diligent in using bottled water for ingestion purposes. Alternative 2 would require extensive
coordination and scheduling for routine water deliveries/drop-offs for each residence.

Similar to Alternative 2, the long-term effectiveness of Alternative 3 (POETS/POUTS) depends
on the residents being diligent in using treated water for ingestion purposes and the installed
POETS/POUTS functioning properly. During previous removal actions at the Site, the POETS had
difficulty functioning as intended. This was the result of by-pass valves unintentionally being
turned on, or treatment solutions not properly reducing contaminants to acceptable levels.
Therefore, Alternative 3 requires continuous maintenance and oversight to ensure the technical
components of POETS/POUTS are functioning properly at each residence.

23

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Alternative 4 (Installing Deeper Drinking Water Wells) would be more reliable than Alternatives
2 and 3 at eliminating the risk to residents exposed to contaminated groundwater by
eliminating the reliance on the resident's diligence and filter monitoring and maintenance.
However, long-term effectiveness could be impacted by the potential of contaminating the
deeper aquifer by drilling a large number of well points through the confining layers of the
shallow aquifer. Long-term monitoring would also be needed to ensure that Site-related
contaminants don't migrate to the deeper aquifer over time. Additionally, Alternative 4 is
reliant on the deeper aquifer's ability to produce the necessary amount of water for all
residences.

Alternative 5 (Connection to Public Water Line and ICs) would be the most effective long-
term remedy because it would permanently eliminate the exposure pathway and provide
residents with a treated and monitored water supply through the connection to a public
water system. The Town of Blade's current water system is being effectively treated and
sampled on a reoccurring basis which demonstrates long-term effectiveness. Additionally,
ICs would prevent the installation of new potable wells until groundwater is restored to its
designated beneficial use. Alternatives 2, 3, and 4 are individual systems at a large number
of residences that would require more rigorous monitoring, maintenance, oversight, and
coordination than a single public water system. A single public water system poses the
least amount of residual risk.

4. Reduction of Toxicity. Mobility, or Volume throughTreatment

None of the alternatives evaluated reduce toxicity, mobility, or volume through treatment
processes.

Groundwater restoration will be addressed in a future OU1 proposed plan and decision
document.

5. Short-Term Effectiveness

Alternative 2 (Bottled Drinking Water) has no short-term risks to the workers providing bottled
water but does have minor short-term risks for the community related to delivery trucks on
local roads and with handling of the bottled water. The RAO would be achieved once bottled
water is supplied to each residence (approximately 1 month following design approval).
Alternative 3 (POETS/POUTS) has minor short-term risks to workers, specifically, if workers
were to come into contact with contaminated groundwater during system installation. This risk
would be mitigated through use of personal protective equipment (PPE). The RAO would be
achieved upon installation of the treatment systems (approximately 6 months following design
approval).

Alternative 4 (Installing Deeper Drinking Water Wells) would have short-term risks for the
community related to well drillers and contractors driving in the neighborhoods. Similar to
Alternative 3, drillers and contractors would mitigate minor short-term risks related to

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contaminated groundwater contact through use of PPE and would conduct work in accordance
with Occupational Safety and Health Administration (OSHA) requirements and implementation
of safe work practices. The RAO would be achieved upon installation of the new private wells
(approximately 6 months following design approval). Alternative 5 (Connection to Public Water
Line and ICs) would have a moderate but temporary disturbance on the local community during
water line (and any needed facilities) installation/construction. Construction workers would
conduct work in accordance with OSHA requirements and implementations of safe work
practices. The RAO would be achieved upon connection to the alternate water supply
(approximately 1 year following design approval).

Alternatives 2, 3, and 4 have similar short-term impacts on workers and community members.
Alternative 5 poses more risk to workers than the other alternatives; however, construction
necessary to connect residences to public water would be conducted in accordance with well-
established worker protection procedures.

6. Implementability

Alternatives 2 (Bottled Drinking Water) and 3 (POETS/POUTS) are easily implementable. The
resources required for implementation are readily available. However, the reliability of
Alternative 2 is based on the residences not using untreated groundwater as a drinking water
source. Alternative 3 also requires continuous maintenance and oversight to ensure the
POETS/POUTS are functioning correctly. There may be times when individual POETS/POUTS are
not functioning properly, which could lead to limited short-term exposure, and would require
diligent maintenance and oversight. Therefore, in terms of technology operation and reliability,
Alternative 3 may not be considered reliable.

Alternative 4 (Installing Deeper Drinking Water Wells) is more difficult to implement than
Alternatives 2 and 3, as it involves installing deep wells at a large number of residences, under
the assumption that the aquifer can adequately provide water to each residence. Test wells
would be needed to confirm the water supply is adequate, and free from contaminants. The
resources required for implementation of this alternative are readily available. Coordination
with local property owners, as well as local and state agencies would be required to locate and
develop a new water supply beneath all impacted residences.

Alternative 5 (Connection to Public Water Line and ICs) includes the most significant amount of
construction for installing water lines and potential new facilities but includes commonly used
technologies and engineering services. The resources required for implementation of this
alternative are readily available. Coordination with local property owners, railroad owners, and
local and state agencies would be required to install new water supply lines/connections to all
affected residences. Coordination with local property owners, as well as local and state
agencies would be required to determine implementation steps that may include temporary
roadway closures and detours.

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Alternative 5 would require more initial construction activities than the other alternatives,
however, the other alternatives would require more frequent maintenance and monitoring at a
large number of residences for as long as is required to remediate the groundwater (presumed
to be 30 years for cost estimation) or indefinitely.

7. Cost

Cost information for alternatives 2,3,4, and 5 over a presumed 30-year period is presented
below. These preliminary cost estimates are anticipated to be within -30 percent to +50 percent
of the actual costs of implementing each alternative. Alternative 2 (Bottled Water) is the least
expensive. Alternatives 3 (POET/POUT) and 5 (Water Line) are similar in cost. Alternative 4
(Deep Wells) has the largest capital cost. See Appendix D for the detailed cost estimate for
Alternative 5 and the Administrative Record for Alternatives 2, 3, and 4.

Table 4: Cost Estimate of Alternatives

Alternative

Description

Capital

O&M

Total

2

Bottled Water

$49,000

$4,094,000

$4,143,000

3

POETS/POUTS

$448,000

$5,753,000

$6,201,000

4

Install Deeper Wells

$7,108,000

$2,465,000

$9,573,000

5

Connection to Public
Water Line and ICs

$5,611,000

$127,000

$5,738,000

8.	State Acceptance

EPA and DNREC have consulted closely during preparation of the Proposed Plan and this ROD
for interim action. DNREC concurred with the Selected Remedy in a letter dated January 12,
2024 (Appendix E).

9.	Community Acceptance

EPA received a limited number of comments and questions concerning the Preferred
Alternative in the Proposed Plan (Alternative 5). A majority of the comments received from the
local community expressed support for EPA's Preferred Alternative. No written comments were
received on the Proposed Plan. All comments provided in the Responsiveness Summary section
are from the July 20, 2023, public meeting. A transcript of the public meeting is available in the
Administrative Record.

XI. SELECTED REMEDY

The Selected Remedy for OU2 is Alternative 5, Connection to Public Water Line and Institutional
Controls. The Selected Remedy will extend a public water line to properties whose private wells
are currently impacted with Site-related contaminants and to those properties that have the
potential to become impacted. The Selected Remedy requires the agreement of residents to

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connect to the public water system. Residents who elect to be connected will have their
existing drinking wells completely disconnected from the house water system and either
abandoned by EPA or converted to non-potable use if the intended use does not pose
unacceptable risk at EPA's expense. Once connected, residents would be responsible for the
recurring water bill. Residents who elect not to be connected would continue to use their
private drinking wells and all associated costs to make a future connection to the public water
supply would be at the homeowner's expense.

The area subject to this Selected Remedy are the residences located south and southwest,
outside of the town limits of Blades, bounded by Morgan Branch and the Nanticoke River as
depicted in Figure 2. This area encompasses the wells that have been impacted and based on
EPA's best professional judgement may be impacted in the future.

Existing POETS/POUTS will be maintained until connection to the public water line is
completed, at which time EPA would no longer maintain the systems. Additionally, institutional
controls such as local ordinances and/or groundwater management zones will be put in place to
prevent the installation of new potable wells until the aquifer is restored to beneficial use
under OU1.

EPA expects that a water line connection will likely be made in the River Road area (Figure 4).
Construction of the new water line will likely need to pass underneath the railroad tracks to
extend to the impacted residences. Erosion and dust control measures will be implemented
during the work. Water mains will be installed, and service connections/supply lines will be
installed at each residence. Repair of roadway pavement and driveways/lawns (as needed) will
be performed.

If additional production is needed for the system to maintain the necessary capacity, EPA
expects a new water supply well will be installed with a pump similar to the existing production
wells (providing a yield of 150 gallons per minute [gpm]) and screened in the lower Choptank
aquifer (approximately 300 feet bgs), which is not anticipated to be hydraulically connected to
the impacted Columbia aquifer. The groundwater from the Choptank aquifer will be sampled to
confirm sufficient yield and absence of contamination. If additional treatment is necessary, EPA
expects that a new treatment facility will be constructed with similar treatment processes as
the Town of Blades' current facility or the current facility will be upgraded. The size will be
appropriate for treating the flow from the new production well (150 gpm). If additional storage
is necessary, a storage tank will be constructed to manage the volume of expanded capacity.

A. Summary of the Rationale for the Selected Remedy

The Selected Remedy (Alternative 5) is most protective of human health because extension of
the public water supply will permanently eliminate the potential use of contaminated
groundwater as a drinking water source. Additionally, the Selected Remedy will provide
drinking water that is required to comply with all drinking water standards. The POETS/POUTS
provided under Alternative 3 can fail and result in short-term exposure until maintenance is

27

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performed, making the Selected Remedy more effective in the long-term. The Selected
Remedy is also readily implementable with relatively limited short-term impacts and is more
cost-effective compared to Alternative's 3 and 4.

Based on the information available at this time, EPA has concluded that the Selected Remedy
(Alternative 5: Public Water Line and ICs) meets the threshold criteria and provides the best
balance of trade-offs when compared to the other alternatives for OU2 with respect to the
balancing criteria. EPA expects the Selected Remedy to satisfy the following statutory
requirements of CERCLA Section 121(b), 42 U.S.C. § 9621(b): 1) to be protective of human
health and the environment; 2) to comply with ARARs (or justify a waiver); 3) to be cost-
effective; and 4) to utilize permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable. With respect to the fifth
statutory requirement, i.e., to satisfy the preference for treatment as a principal element (or
justify not meeting the preference), the Selected Remedy does not satisfy the preference for
treatment as a principal element. However, it does permanently eliminate or reduce the
exposure pathway to contaminated groundwater via residential wells. The final remedial action
for the Site, which will be proposed in a future proposed plan and decision document for OU1
and subject to public participation requirements, will address the remaining contaminated
media at the Site.

B. Summary of the Estimated Costs

The cost of the Selected Remedy (Alternative 5) is estimated to be $5,738,000, which is less
than the estimated cost of $6,201,000 for Alternative 3 and $9,573,000 for Alternative 4.
Detailed cost information for the Selected Remedy can be found in Appendix D.

C. Performance Standards

Performance standards do not apply to the off-Site treatment, under applicable law, of public
water to be supplied by the Town of Blades to residents via the newly installed water line.
Treatment of the public water will be conducted off-Site by the provider in compliance with all
drinking water standards.

D. Expected Outcome of the Selected Remedy

The Selected Remedy is expected to meet the RAO for this ROD for interim action:

• Prevent current and future residential exposure to groundwater containing
unacceptable levels of Site-related COCs.

XII. STATUTORY DETERMINATIONS

The OU2 Selected Remedy is protective of human health and the environment, complies with
Federal and State requirements that are legally applicable or relevant and appropriate to the
interim remedial action, is cost-effective, and utilizes permanent solutions to the maximum

-------
extent practicable.

Because the Selected Remedy will result in hazardous substances remaining onsite above
levels that allow for unlimited use and unrestricted exposure, a review will be conducted within
five years after commencement of the interim remedial action to ensure that the remedy
continues to provide adequate protection of human health and the environment. Such reviews
will be conducted a minimum of every five years thereafter, until EPA determines that
hazardous substances remaining at the Site do not prevent unlimited use and unrestricted
exposure at the Site.

A.	Compliance with Applicable or Relevant and Appropriate Requirements

An interim remedial action must comply with (or waive) those Federal and State requirements
that are applicable or relevant and appropriate to the limited-scope action. Therefore, the
focus is only on those ARARs specific to this interim remedial action. While the final remedial
action for OU1 will address the remaining Site-related contamination in all media, this interim
remedial action for OU2 will implement limited action to prevent human exposure to
contaminated groundwater in residential wells. The final remedial action for OU1, after any
necessary public participation requirements are met, will address the remaining unacceptable
risks presented by the Site.

A complete list of ARARs and TBCs for the Selected Remedy for OU2 is provided in Appendix B.
The major ARARs identified therein include, but are not limited to:

•	National Primary Drinking Water Standards: 40 C.F.R. §§ 141.50, 141.61 and 141.62
establish health-based standards (i.e., Maximum Contaminant Level Goals (MCLGs) and
MCLs) for public drinking water.

•	Delaware Regulations Governing the Construction and Use of Wells: 7 Del. Admin. C.
§7301 contains requirements governing the location, design, installation, use,
modification, repair, and sealing of all wells and associated equipment as well as
requirements for public and private potable wells.

B.	Cost-Effectiveness

The NCP, at 40 C.F.R. § 300.430(f)(l)(ii)(D), requires EPA to evaluate cost-effectiveness by
evaluating all the alternatives meeting the threshold criteria (protection of human health and the
environment and compliance with ARARs) against long-term effectiveness and permanence,
reduction of toxicity, mobility or volume through treatment, and short-term effectiveness to
determine overall effectiveness. Then overall effectiveness is compared to cost to determine
cost-effectiveness. As presented in Section X (Comparative Analysis of Alternatives), above, the
Selected Remedy provides the most long-term effectiveness and permanence, followed by
Alternative 4, and significantly trailed by Alternative 3 and then 2. All four alternatives are
evaluated equally for purposes of reduction of toxicity, mobility and volume through treatment

29

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since none of the alternatives would treat COCs. Each of the alternatives would pose a
manageable amount of impact on effectiveness in the short term. Thus, the Selected Remedy is
strongest in overall effectiveness. Further, Alternative 5, the Selected Remedy, is less costly
than Alternatives 4 and 3, the next most cost effective alternatives.

The Selected Remedy is cost-effective in providing overall protection of human health and the
environment by limiting the risk posed by Site COCs and meets all other requirements of
CERCLA and the NCP at a cost that is proportional to or less than the other alternatives that
were evaluated. Further, the Selected Remedy is readily implementable and provides a high
degree of both short- and long-term effectiveness. The estimated present value of the Selected
Remedy is approximately $5,738,000.

C. Utilization of Permanent Solutions and Alternative Treatment Technologies to
the Maximum Extent Practicable and Preference for Treatment as a Principal
Element

The Selected Remedy is an interim remedial action to protect people from exposure to
contamination in drinking water from groundwater. The Selected Remedy is not intended to
treat contamination or provide a permanent solution to contamination in groundwater. A
future proposed plan and decision document will address remaining contamination present in
all media at the Site for OU1.

D. Five Year Review Requirements

CERCLA Section 121(c), 42 U.S.C. § 9621(c), and Section 300.430(f)(4)(ii) of the NCP, 40 C.F.R. §
300.430(f)(4)(ii), require review of a remedy if the remedy results in hazardous substances,
pollutants, or contaminants remaining on-site above levels that allow for unlimited use and
unrestricted exposure. Any such review must be conducted no less often than every five years
after initiation of the interim remedial action.

Because hazardous substances will remain at the Site, the review required by Section 121(c) of
CERCLA and Section 300.430(f)(4)(ii) of the NCP will be conducted no less often than every five
years after initiation of the interim remedial action.

E. Documentation of Significant Changes

The Proposed Plan was released for public comment on June 29, 2023. EPA has reviewed all
comments submitted during the public comment period and determined that no significant
changes were necessary or appropriate to be made to the Selected Remedy, as originally
identified as the Preferred Alternative in the Proposed Plan.

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3. RESPONSIVENESS SUMMARY

This Responsiveness Summary summarizes the significant comments and concerns received
during the public comment period for the Proposed Plan for the Site and provides EPA's
responses to those comments. After reviewing and considering all public comments received
during the public comment period, EPA's Selected Remedy for OU2 \s Alternative 5—
Connection to Public Water Line and ICs.

The Proposed Plan and supporting documents were made available to the public in the
Administrative Record File, which was compiled to support selection of this Interim Remedial
Action. EPA provided notice to the public that the Administrative Record File could be viewed
online at https://semspub.epa.gov/src/collection/03/AR67374. or at the following locations:

Seaford District Library
600 N. Market Street
Seaford, DE 19973
Mon-Fri 10:00 am to 6:00 pm
(302) 629-2524

EPA Administrative Records Room

Administrative Records Coordinator

Four Penn Center

1600 John F. Kennedy Boulevard

Philadelphia, PA 19103

Phone:(215) 814-2469

Hours: Monday - Friday 8:30 am to 4:00 pm

By appointment only

The notice of availability of these documents was published in the Seaford Star and a fact sheet
detailing the Proposed Plan was mailed to local citizens on June 29, 2023.

A public comment period was held from June 29, 2023, until July 28, 2023. EPA held a public
meeting on July 20, 2023, at the Blades Fire Company, located at 200 E. 5th Street, Blades,
Delaware 19973. During the public meeting, EPA gave a formal presentation on EPA's Proposed
Plan, followed by a "Question and Answer" session where representatives from EPA answered
questions regarding the Site and the Proposed Plan. No written comments were received on
the Proposed Plan.

July 20. 2023 Public Meeting

All comments provided in this Responsiveness Summary are from the July 20, 2023 public
meeting. At this meeting, numerous question and comments were posed. Several of these
questions and comments did not pertain to OU2 and the specific cleanup alternatives from the
Proposed Plan and, thus, are not provided in this Responsiveness Summary. Below is a
summary of the public comments and EPA's responses during the public meeting. Repeated
questions and comments received during the public meeting are only listed once and similar
questions and comments are grouped together.

For full questions and corresponding answers provided at the public meeting, please see the
transcript of the public meeting, which is included in the Administrative Record.

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Comments Related to OU2 and the Specific Cleanup Alternatives from the Proposed Plan

Comment #1: A commentor asked if the distribution of public water would be metered.

EPA Response: EPA responded, yes, the water would be metered. Once connected,
residents would be responsible for the recurring water bill.

Comment #2: A commentor asked if the existing POET/POUT systems can stay in the house if
they want to keep it (post water line installation).

EPA Response: EPA responded that residents could keep the existing POET/POUT
system(s). However, EPA would no longer maintain the systems and the
cost/maintenance would be the responsibility of the resident.

Comment #3: A commentor mentioned they live in an area that would be at the end of the
proposed water line. They asked what happens to all the material and chemicals that flush
down the water line and expressed concerns about being at the end of the line and receiving
the residual material.

EPA Response: The design of the water line would be fully determined during the design
phase, but it is common for water lines to be configured as loop systems rather than
capping at the end of a road. The loop system would be considered on this project.

Comment #4: A commentor asked what the charge would be for the wastewater. The
commentor elaborated they would get charged for how much water they use, plus the sewage
going back. The commentor asked if that is included or if it would be separate.

EPA Response: EPA responded that the Preferred Alternative only involves providing
public water connections and does not include sewage/wastewater.

Comment #5: A commentor expressed their concern with the amount of water volume the
water line is going to take and whether the aquifer will be sustained. They asked will the aquifer
be able to handle this.

EPA Response: This information would be considered and determined during the design
phase. This includes activities such as aquifer testing to understand if and how
additional home connections would influence the aquifer.

Comment #6: A commentor asked, "what's the water pressure to the line?"

EPA Response: EPA did not know the exact water pressure at the time of this question
but ensured those present that the water line would meet all minimum water pressure
requirements and considerations for pounds per square inch (PSI) would be evaluated

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during the design phase for all piping structures.

Comment #7: A commentor asked if they could keep their well for irrigation because it would
be too costly to irrigate their land using public water.

EPA Response: EPA encouraged residents to allow EPA to abandon their well because of
unknown potential future risks from contamination, but EPA responded that as of now,
yes, residents can keep their private well for non-potable use if risks related to the
intended use allow for it.

Comment #8: A commentor asked if Blades has any plans to incorporate/annex the residents
outside of the town limits into the town. The commentor expressed opposition to this.

EPA Response: EPA responded that the current plan is to annex the residents into the
water authority but not into the Town of Blades.

Comment #9: A commentor asked if someone wants to build a new house or new building on
vacant parcels, will they be able to connect to the water line.

EPA Response: EPA responded certainly they can connect to the water line. If the new
construction occurs after the implementation of the water line, the property owner
would be responsible to cover the cost to connect.

Comment #10: A commentor asked if EPA has a time frame for all of this to happen.

EPA Response: EPA responded that following this public meeting the next step is to
develop the Record of Decision which may take approximately six months from now to
complete. The second phase is to design the remedy. Typically, designs take anywhere
from two to three years, but this period could vary with unforeseen circumstances.
Following the design approval, it is estimated the remedial action would be
implemented in one year.

Comment #11: A commentor asked, "what's the cost for the monthly water bill?"

EPA Response: EPA responded that according to the Blades municipality website, there
is a minimum $35.00/month charge that will cover the first 3,000 gallons. Any additional
usage is charged at $6.15/1,000 gallons.

Comment #12: A commentor in support of EPA's previous response to Comment #9 stated that
when they moved to town, they took advantage of connecting to the Blade's public water line
(formerly on private well water). They stated that the house includes two and a half baths and,
with comfortable water usage, their water bill is in fact $35. They stated that the contractors
the Town of Blades hired to connect the house to the water line were very cordial and mindful
of the residents and their property. The experience was fantastic, and it exceeded their

33

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expectations. The commentor said that, before connecting to public water, they had concerns
similar to those expressed by others in the meeting about water bills but the commenter was
pleasantly surprised with the process.

EPA Response: EPA thanked the commentor for their support and for offering their real-
life experience from a similar project.

Comment #13: A commentor asked if something was going to be done for the 73 families that
are affected over the two- or three-year period waiting for the water line to be installed.

EPA Response: EPA stated that the 73 homes includes homes that are currently
impacted, and homes that have the potential to be impacted over time, should
contamination migrate. Based upon the residential sampling efforts, the homes that had
elevated concentrations of contamination in their well water were addressed by EPA
through a Removal Action where treatment systems were installed at the residences.

Comment #14: A commentor asked if EPA felt comfortable to install a well to some depth that
was not contaminated. They asked if 300 feet was deep enough.

EPA Response: EPA stated that the nature and extent of contamination is still being
assessed under Operable Unit 1. It is the agency's current understanding that the
contamination is primarily in the shallow aquifer, however, there may be areas where
groundwater migrates deeper.

To that point, one of the alternatives that was evaluated (Alternative 4) was targeting
new deep wells 250-300 feet below ground surface into the Choptank Aquifer. This
aquifer/depth is desirable because the St. Mary's confining unit overlays the Choptank
Aquifer which would act as a barrier in the event contamination migrates vertically to
that depth. EPA also explained that the downside of drilling a large number of wells
through the confining layer is that it may create pathways for contamination to migrate
vertically into the Choptank Aquifer.

Comment #15: A commentor asked what the life expectancy of the carbon filters is that are
currently being used by the Town of Blades. The commentor elaborated there was a quote in
the News Journal at the time the carbon filters were installed on the public water that said the
filters would eventually be spent. The commentor asked who would absorb the cost of
replacing these filters.

EPA Response: EPA indicated the Town of Blades, as the water authority, would be
responsible for replacement of the treatment system carbon filters. EPA indicated there
has been ongoing monitoring to evaluate over time to determine how the carbon is
functioning and if there is any evidence of contaminant breakthrough (exceeding or
close to exceeding drinking water standards). While EPA cannot predict the exact life
expectancy of the carbon filters, EPA did mention that the public water has been

34

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sampled 12 times on a quarterly basis and has not shown signs of breakthrough.

After further consideration of the question and post-meeting discussions with DNREC,
EPA would like to clarify and expand the response. The length of time that carbon will
remain effective is not based on a fixed length of time but is based on the variable
conditions such as the amount of water flowing through the treatment system,
contaminant concentrations and other water chemistry conditions. The best way to
determine when to replace the carbon is based on the effluent concentration
(determined from testing a water sample collected after the water has passed through
the carbon treatment system). The groundwater analytical result concentrations
collected from the effluent are analyzed over time. The water provider uses the data to
determine when the concentrations will become close to exceeding the drinking water
standard or when the contaminant levels could be expected to exceed the drinking
water standard; at that time, the carbon will be replaced. Since the effluent
concentrations are still very low, EPA is not able to estimate when to expect
breakthrough and thus is not able to determine when the carbon will need to be
replaced.

Comment #16: A commentor asked if EPA will continue to monitor the treated water after the
water line is in.

EPA Response: EPA stated that the water provider is responsible for the ongoing
treatment and sampling of provided water. After the commentor expressed concerns
regarding whether the water provider will faithfully ensure the quality of the public
water, EPA indicated there are annual water quality reports and publicly available
information to provide the community with results and provide confirmation to the
community that the treatment is functioning properly.

Comment #17: A commentor asked, "If EPA came in and found the PFAS contamination, how
come Blades didn't find this years ago?"

EPA Response: EPA cannot comment on behalf of the Town of Blades, however, PFAS is
a relatively recently discovered contaminant in groundwater. Until 2018, EPA and DNREC were
not aware that PFAS could be in drinking water or that sampling for PFAS was necessary. As
PFAS became better understood, including the industrial uses of the compound, it prompted
EPA and DNREC to begin investigating.

Comment #18: A commentor asked if any wells have been tested on the other side of Morgan
Branch.

EPA Response: EPA stated the current understanding is OU2 is hydraulically bounded by
the Nanticoke River and Morgan Branch. As the OU1 remedial investigation continues, if
evidence is discovered suggesting the contamination is migrating beyond the water
body boundaries, EPA will respond accordingly.

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Comment #19: A commentor asked, "If the water should all of a sudden clear up in the next
four or five years, can I go back using my private well?"

EPA Response: EPA stated that the Selected Remedy will be implemented until groundwater is
restored to its beneficial use. When the groundwater no longer poses an unacceptable risk to
human health and the environment, the commenter can go back to using their private well for
drinking water. However, EPA noted restoration of groundwater to beneficial use can take
decades.

36

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FIGURES

Figure 1: Site Location Map
Figure 2: Site Layout

Figure 3: 2021-2022 Residential Well Sampling
Figure 4: Selected Remedy - Water Main Extension

37

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38

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Legend

ra Town of Blades Boundary

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Figure 2
Site Layout

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Revised: 4/28/2023

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39

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40

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Legend

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41

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APPENDIX A
ADMINISTRATIVE RECORD INDEX

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III
1600 John F. Kennedy Blvd.

Philadelphia, Pennsylvania 19103

BLADES GROUNDWATER
OU 2 REMEDIAL ACTION ADMINISTRATIVE RECORD FILE

INDEX OF DOCUMENTS
AVAILABLE 6/29/2023, UPDATED//2024
https://semspub.epa.gov/src/collection/03/AR67374

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Introduction

The "Administrative Record" is the collection of documents which form the basis for the U. S.
Environmental Protection Agency's (EPA) selection of a response action at a Superfund site.
Superfund is the name given to the Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA) which can be found in Title 42 of the U.S. Code (U.S.C.) at Sections
9601 through 9675. Response actions under Superfund can be either "removal actions" or
"remedial actions." As the EPA decides what to do at the site of a release of hazardous
substances, the EPA compiles documents concerning the site and EPA's decision into an
"Administrative Record File." Documents may be added to the Administrative Record File from
time to time. Once the EPA Regional Administrator or the Regional Administrator's delegate
signs the decision document memorializing the selection of an action, the documents which
form the basis for the selection of an action are known as the "Administrative Record." An
Administrative Record file is required by CERCLA, as amended by the Superfund Amendments
and Reauthorization Act (SARA).

The Administrative Record will be available for public review during normal business hours in an
electronic computer imaged format at the selected repository and by appointment only at the
Environmental Protection Agency (EPA), Region 3 office which is located at the address given on
the cover page. The Administrative Record is treated as a non-circulating reference document.
Individuals may review documents contained in the Administrative Record, according to the
procedures at the local repository and at the EPA Region 3 office. The Administrative Record
will be maintained at the repository until further notice. EPA may send additional documents to
the repository as work progresses at the Site. The EPA may hold formal public comment periods
at certain stages of the response process. The public is urged to use the formal public comment
periods to submit written comments to the EPA regarding the actions at the Site.

Except as explained below, this index and the record were compiled in accordance with the
EPA's Revised Guidance on Compiling Administrative Records for CERCLA Response Actions,
EPA/OSRE/OEM/OSRTI (September 20, 2010), and/or in accordance with Superfund Removal
Procedures Public Participation Guidance for On-Scene Coordinators: Community Relations and
the Administrative Record, OSWER 9360.3-05 (July 1992), and/or the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part 300. Consistent with 40
CFR Sections 300.805 (a) (2), and 300.810 (a) (2), Region 3 has listed, in the Administrative
Record Index (or in bibliographies of documents listed in the Index), guidance documents which
may form a basis for the selection of this response action (EPA Guidance Documents, Non-Site
Specific). Unless the guidance documents indexed were generated specifically for the Site, the
guidance documents may not be present in the Administrative Record. However, it should be
noted that the EPA does maintain an extensive collection of Superfund response action
guidance documents available in electronic format on the EPA website at:
https://www.epa.eov/superfund/superfund-policy-euidance-and-laws.

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Additionally, the EPA guidance related to Superfund cleanup enforcement may be found on the
website at the following address:

http://cfpub.epa.eov/compliance/resources/policies/cleanup/superfund.

This page is titled, "Superfund Cleanup Policies and Guidance."

The Administrative Record is listed in chronological order with the earliest dated document at
the top and followed by documents which may be "Undated."

Documents in the Administrative Record File have been redacted due to the presence of
confidential business information, personal identifiable information, and/or other privileged
materials. The redactions are evident from the face of the document and the word "Redacted"
appears in the title on the index.

3

-------
OU 2 REMEDIAL ACTION ADMINISTRATIVE RECORD FILE
BLADES GROUNDWATER	INDEX OF DOCUMENTS	In CHRONOLOGICAL Order

Updated //2024

DOC ID

DOC DATE

TITLE

PAGE COUNT

ADDRESSEE NAME

AUTHOR NAME

2342514

02/16/2021

REDACTED FINAL FIELD SAMPLING PLAN

110

ROVIRA,EDUARDO (EPA)

SOLLENBERGER,CHRIS (TETRATECH INC.)

2342512

04/01/2021

REDACTED FINAL COMPREHENSIVE QUALITY ASSURANCE
PROJECT PLAN (QAPP) - REVISION 1

134

(EPA)

(AECOM)

2342510

04/08/2021

REDACTED DRAFT TRIP REPORT - BACKGROUND MONITORING
WELL INSTALLATION (COVER LETTER ATTACHED)

30

TAYLOR,DANIEL (EPA)

SOLLENBERGER,CHRIS (TETRATECH INC.)

2342509

11/01/2021

REDACTED AMENDMENTTO COMPREHENSIVE QUALITY
ASSURANCE PROJECT PLAN (QAPP) - REVISION 2

15

(EPA)

(AECOM)

2339302

12/06/2021

REDACTED TRIP REPORT - 6/2021 PUBLIC WATER SUPPLY
SAMPLING EVENT

30

TAYLOR,DANIEL (EPA)

(AECOM)

2336396

12/21/2021

REDACTED FINAL TRIP REPORT - 4/2021 SECOND QUARTERLY
GROUNDWATER SAMPLING EVENT (COVER LETTER ATTACHED)

155

(EPA)

(TETRATECH)

2336398

12/21/2021

REDACTED FINAL TRIP REPORT - 7/2021 SECOND QUARTERLY
GROUNDWATER SAMPLING EVENT (COVER LETTER ATTACHED)

163

(EPA)

(TETRATECH)

2336399

03/01/2022

REDACTED TRIP REPORT -11/2021 THIRD QUARTERLY
BACKGROUND WELL SAMPLING EVENT

17

TAYLOR,DANIEL (EPA)

(AECOM)

2334965

03/22/2022

ACTION MEMORANDUM: REQUEST FOR FUNDS FOR REMOVAL
ACTION & CONSISTENCY EXEMPTION FROM 12-MONTH LIMIT

10

LEONARD,PAUL (EPA)

LEONARD,PAUL (EPA) | ROVIRA,EDUARDO
(EPA) |TOWLE,MICHAEL,T (EPA)

2345902

04/04/2022

REDACTED TRIP REPORT - 9/2021 & 10/2021 RESIDENTIAL
WELL SAMPLING EVENT

102

TAYLOR,DANIEL (EPA)

(AECOM)

2339303

04/27/2022

REDACTED TRIP REPORT -1/2022 PUBLIC WATER SUPPLY
SAMPLING EVENT

12

TAYLOR,DANIEL (EPA)

(AECOM)

2339304

04/27/2022

REDACTED TRIP REPORT -10/2021 PUBLIC WATER SUPPLY
SAMPLING EVENT

14

TAYLOR,DANIEL (EPA)

(AECOM)

2336397

04/27/2022

REDACTED TRIP REPORT -1/2022 FOURTH QUARTERLY
BACKGROUND WELL SAMPLING EVENT

45

TAYLOR,DANIEL (EPA)

(AECOM)

2342513

06/01/2022

REDACTED FINAL REMEDIAL INVESTIGATION WORK PLAN

406

(EPA)

(AECOM)

2342508

06/01/2022

REDACTED FINAL COMPREHENSIVE QUALITY ASSURANCE
PROJECT PLAN (QAPP)

241

(EPA)

(AECOM)

2338485

06/27/2022

OU 2 SCREENING OF ALTERNATIVES

8

TAYLOR,DANIEL (EPA)

(AECOM)

2342511

08/01/2022

REDACTED OU 2 FINAL REMEDIAL INVESTIGATION REPORT

456

TAYLOR,DANIEL (EPA)

(AECOM)

2338587

08/08/2022

TRIP REPORT - 5/2022 EXISTING MONITORING WELL
INVENTORY & STREAM GAUGE INSTALLATION EVENT

8

TAYLOR,DANIEL (EPA)

(AECOM)

4

-------
OU 2 REMEDIAL ACTION ADMINISTRATIVE RECORD FILE
BLADES GROUNDWATER	INDEX OF DOCUMENTS	In CHRONOLOGICAL Order

Updated //2024

DOC ID

DOC DATE

TITLE

PAGE COUNT

ADDRESSEE NAME

AUTHOR NAME

2334964

08/11/2022

ACTION MEMORANDUM: REQUEST FOR ADDITIONAL FUNDS
FOR REMOVAL ACTION & CHANGE OF SCOPE

9

LEONARD,PAUL (EPA)

LEONARD,PAUL (EPA) | ROVIRA,EDUARDO
(EPA) |TOWLE,MICHAEL,T (EPA)

2339300

08/26/2022

REDACTED TRIP REPORT - 4/2022 PUBLIC WATER SUPPLY
SAMPLING EVENT

31

TAYLOR,DANIEL (EPA)

(AECOM)

2339306

09/13/2022

REDACTED FINAL TRIP REPORT - 4/2022 & 5/2022 RESIDENTIAL
WELL RESAMPLING EVENT

12

TAYLOR,DANIEL (EPA)

(AECOM)

2342522

11/22/2022

REDACTED TRIP REPORT - 7/2022 PUBLIC WATER SUPPLY
SAMPLING EVENT

14

TAYLOR,DANIEL (EPA)

(AECOM)

2342525

12/02/2022

REDACTED TRIP REPORT - 7/2022 RESIDENTIAL WELL
CONFIRMATION SAMPLING EVENT

14

TAYLOR,DANIEL (EPA)

(AECOM)

2342516

12/06/2022

TRIP REPORT - 7/2022 EXISTING WELL SAMPLING & SYNOPTIC
GAUGING EVENT

103

TAYLOR,DANIEL (EPA)

(AECOM)

2345901

01/01/2023

REDACTED OU 2 FINAL DETAILED ALTERNATIVES EVALUATION

114

(EPA)

(AECOM)

2345900

02/01/2023

REDACTED OU 2 FINAL FEASIBILITY STUDY (FFS)

138

(EPA)

(AECOM)

2342524

02/21/2023

REDACTED TRIP REPORT - 8/2022 & 10/2022 RESIDENTIAL
WELL CONFIRMATION SAMPLING EVENTS

14

TAYLOR,DANIEL (EPA)

(AECOM)

2342523

03/10/2023

REDACTED TRIP REPORT -10/2022 PUBLIC WATER SUPPLY
SAMPLING EVENT

14

TAYLOR,DANIEL (EPA)

(AECOM)

2345102

05/08/2023

MEMO TO FILE REGARDING UPDATES FROM
FEASIBILITY/REMEDIAL ALTERNATIVE EVALUATION &
PROPOSED PLAN

21

(FILE)

TAYLOR,DANIEL (EPA)

2347864

06/01/2023

FACT SHEET: EPA PROPOSES PLAN TO PROVIDE CLEAN WATER
TO AFFECTED RESIDENTS

4



(EPA)

2347865

06/29/2023

OU 2 PROPOSED REMEDIAL ACTION PLAN (PRAP)

28



(EPA)

2368370

07/20/2023

OU 2 PROPOSED REMEDIAL ACTION PLAN (PRAP) PUBLIC
MEETING TRANSCRIPT

93



(LEXITAS LEGAL)

2368369

11/06/2023

OU 2 PROGRAMMATIC AGREEMENT AMONG EPA &
DELAWARE STATE HISTORIC PRESERVATION OFFICE (COVER
LETTER ATTACHED)

19



KILLSCROW,BRAD (DELAWARE TRIBE OF
INDIANS) | LEONARD,PAUL
(EPA) | RATSEP,TIMOTHY (DE DEPT OF
NATURAL RESOURCES &
ENVIRONMENTAL CONTROL
(DNREC))|SAVERY,SUZANNE (DELAWARE
STATE HISTORIC PRESERVATION OFFICE)

5

-------
APPENDIX B
ARARs and TBCs

-------
ARAR

Citation

Class

Synopsis

Relevance to Remedy

Chemical-Specific

Maximum Contaminant

40 C.F.R. §§

Relevant and

Establishes maximum contaminant levels

Groundwater in the area of concern is currently

Levels (MCLs) promulgated

141.61 and

appropriate

(MCLs) for common organic and inorganic

being used as a source of drinking water for

under the Safe Drinking

62.



contaminants, which are applicable to

residents. MCLs establish health-based standards

Water Act of 1974, as





public drinking water supplies.

(i.e., MCLs) for public drinking water. MCLs are

amended, 42 U.S.C. §§ 300f







relevant and appropriate since the selected

et seq. (SDWA)







remedy of a public drinking water line is required
to meet MCLs in order to provide potable water to
residents.

Safe Drinking Water Act,

40 C.F.R. §

Relevant and

Establishes non-zero maximum

Ground water in the area of concern is currently

National Primary Drinking

141.51(b).

appropriate

contaminant level goals (MCLGs) for public

being used for public consumption by residents. A

Water Regulations- MCL





water supplies. MCLGs are health goals for

public drinking water supply line will be designed

Goals (MCLGs)





drinking water sources.

and implemented to supply drinking water to all
residences in OU2.

Drinking Water Health

None

To Be

Health Advisories are estimates of risk

PFAS compounds have been detected in the area of

Advisory for PFOA and PFOS



Considered

from consumption of contaminated

this interim remedial action.

(EPA Office of Drinking





drinking water. They provide information



Water), 2016





on contaminants that can cause human
health effects and are known or
anticipated to occur in drinking water.



Interim Drinking Water

None

To Be

Health Advisories are estimates of risk

PFAS compounds have been detected in the area of

Health Advisory for



Considered

from consumption of contaminated

this interim remedial action.

perfluorooctanoic acid





drinking water. They provide information



(PFOA) [EPA 822-R-





on contaminants that can cause human



22-003] and





health effects and are known or



perfluorooctanesulfonic





anticipated to occur in drinking water.



acid (PFOS) [EPA 822-









R-22-004] (EPA Office









of Water), 2022









EPA Proposed National

None

To Be

Establishes a proposed maximum

PFAS compounds have been detected in the area

Primary Drinking Water



Considered

contaminant level for PFOA and PFOS

subject to this interim remedial action.

Regulation (NPDWR) for





applicable to all public water supplies



PFOA, PFOS, PFNA, HFPO-DA,





Nationwide.



PFHxS, and PFBS.









Delaware Regulations

16 Del.

Relevant and

These regulations define the maximum

Groundwater in the area of concern is currently

Governing Drinking Water

Admin. C. §

Appropriate

contaminant levels (MCLs) for potable use

being used as a source of drinking water for

-------
Systems

4462-9.0.



of groundwater.

residents. MCLs establish health-based standards
(i.e., MCLs) for public drinking water. MCLs are
relevant and appropriate since the selected
remedy of a public drinking water line is required
to meet MCLs in order to provide potable water to
residents.

Delaware Proposed Statute
Governing Drinking Water
Systems

Del. H.B. 8,
151st Gen.
Assem.
(2021).

To Be
Considered

Delaware has proposed a statute directing
DNREC and DPH to work together to issue
primary MCLs for PFOA and PFOS. In
anticipation, Delaware DPH has issued an
implementation plan proposing MCLs for
PFOS-14 parts per trillion/liter (ng/l),
PFOA-21 ng/l and combined 17 ng/l.

PFAS compounds have been detected in the area of
this interim remedial action.

ARAR

Citation

Class

Synopsis

Relevance to Remedy

Location-Specific

Regulations promulgated
under Section 106 of the
National Historical
Preservation Act of 1966, as
amended (NHPA) 54 U.S.C. §
306108

36 C.F.R
Part 800

Applicable

Section 106 of the NHPA requires any
Federal undertaking to consider the effect
the activity may have on any historic
property. It is the responsibility of a
Federal agency to identify historic
properties potentially affected by an
undertaking, assess its effects and seek
ways to avoid, minimize or mitigate any
adverse effects on historic properties.

The water line construction meets the definition of
an "undertaking" under 36 C.F.R. § 800.16(y).
Accordingly, EPA will take the appropriate steps to
identify historic property and then after assessing
its potential effects, seek ways to avoid, or
minimize those effects.

Regulations under the
Migratory Bird Treaty Act of
1918, as amended ("MBTA"),
16 U.S.C. § 703

16 U.S.C. §
703 and 50
C.F.R. §
10.13

Applicable

Section 703 of the MBTA prohibits the take
(including killing, capturing, selling,
trading, and transport) of protected
migratory bird species that are native to
the United States without prior
authorization by the U.S. Fish and Wildlife
Services("FWS"). The species protected as
migratory birds under the MBTA are listed
in 50 C.F.R. § 10.13.

Appropriate actions will be taken during the water
line construction to ensure that no on-Site
migratory birds listed at 50 C.F.R. § 10.13, or their
nests are adversely affected.

Consultation requirements
under Section 7 of the
Endangered Species Act of

50 C.F.R. §§

402.01-

402.17

Applicable

The ESA requires consultation between
the FWS and other Federal agencies to
ensure that any agency action authorized,

Consultation will occur with FWS to ensure the
water line construction does not jeopardize the
continued existence of any endangered or

-------
1973, as amended ("ESA"),
16 U.S.C § 1536

funded, or carried out by these agencies is
not likely to jeopardize the continued
existence of any endangered or
threatened species or result in the
destruction or adverse modification of
habitat of such species.

threatened species or result in the destruction or
adverse modification of habitat of these species.

Protection of Floodplains

44 C.F.R §§
9.2-9.18

Relevant and
Appropriate

Requires minimization of harm to or within
the floodplain.

There is a potential for work to be performed
within the floodplains of the Nanticoke River and
Morgan Branch. 6

Protection of Wetlands

44 C.F.R §§
9.2-9.18

Relevant and
Appropriate

Requires the minimization of the
destruction, loss, or degradation of
wetlands.

Requires the preservation and
enhancement of the natural and beneficial
wetlands values.

There is potential for work to be performed that
may impact wetlands.7

ARAR

Citation

Class

Synopsis

Relevance to Remedy

Action-Specific

Stormwater regulations
promulgated under the CWA,
33 U.S.C. §§ 1251 et seq.

40 C.F.R. §
122.26(c)(1)

(ii)

Relevant and
Appropriate

This regulation requires the operator of a
new stormwater discharge associated with
small construction activity, as defined by
40 C.F.R. § 122.26(b)(15), to maintain
certain information about the nature of
the site, the nature of on-site activities,
proposed best management practices to
control pollutants in stormwater during

Provides best management practices to control
contaminants of concern in stormwater during the
construction of the water line. Information
required to be maintained under this regulation
will be reported to appropriate Delaware and
Federal officials. No permit will be obtained.8

6 See also (1) Executive Order 11988, Section 1 (which requires action to reduce the risk of flood loss, to minimize the impact of floods on human safety, health and
welfare, and to restore and preserve the natural and beneficial values served by floodplains) and 2(a)(2) (which requires consideration of alternatives to avoid
adverse effects and incompatible development in floodplains); (2) Executive Order 13690, Section 2(c) (which requires use of natural systems, ecosystem processes,
and nature-based approaches when developing alternatives for consideration). Federal Agencies are required to comply with executive order requirements.

7 See also Executive Order 11990, Section 1(a) (which requires action to minimize the destruction, loss, or degradation of wetlands and to preserve and enhance
beneficial values of wetlands) and 2(a) (which requires taking action to avoid construction in wetlands unless there is no practicable alternative to such construction
and the proposed action includes all practicable measures to minimize harm to wetlands which may result from such use). Federal Agencies are required to comply
with executive order requirements.

8 See 42 U.S.C. § 9621(e) and 40 C.F.R. § 300.400(e) (No Federal, state, or local permit is required for the on-site portion of a response action conducted under
Section 104 of CERCLA. The term on-site means the areal extent of contamination and all suitable areas in very close proximity to the contamination necessary for
implementation of the response action.)

-------






and after construction activities, an









estimate of the runoff coefficient of the









site, and the name(s) of the receiving









water(s).



Delaware Hazardous

7 Del. C. Ch.

Relevant and

HSCA gives DNREC the authority to ensure

The interim remedy being implemented at the site

Substance Cleanup Act

91.

Appropriate

cleanup of facilities with a release or

will be conducted under oversight from Delaware

(HSCA)





imminent threat of release of hazardous
substances.

HSCA.

Delaware Regulations

7 Del.

Relevant and

Establishes the long-term stewardship of a

The regulations will establish institutional controls,

Governing Hazardous

Admin. C. §

Appropriate

remedial action including maintenance,

such as a groundwater management zone that may

Substance Cleanup

1375-12.7.5



monitoring environmental covenants, and
required compliance with institutional
controls.

be required following completion of the remedy.

Delaware Regulations

16 Del.

Applicable

Establishes plans and specifications for the

The interim remedy chosen for implementation is

Governing Drinking Water

Admin. C. §



construction of a new public water supply

the construction and installation of a public water

Systems

4462-1.11.



or alteration of an existing public water
supply.

supply line to serve the area of concern.

Delaware Regulations

26 Del. C. §

Relevant and

Establishes regulations of all public utilities

The chosen interim remedy is the installation of a

Governing Public Service

203C

Appropriate

including their rates, property rights,

public water line.

Commission





equipment, facilities, service territories
and franchises. These regulations address
the expansion of a water supply lines.



Delaware Sediment and

7 Del.

Relevant and

Establish the Delaware statewide sediment

The interim remedy being implemented is

Stormwater Regulations

Admin. C. §§

Appropriate

and stormwater management plans

construction of a public water utility line. Sections



5101-3.4.1.5



requirements including those for

3.4.1.5 and 3.7.15 are relevant and appropriate to



and 3.7.15



dewatering of trenches and minor liner
utility disturbances.

any soil disturbance for the water line installation if
the soil disturbance is greater than 1.0 acres, all the
requirements for the Construction General Permit
will be required including minimizing sediment
tracking and removing of the sediment from the
roadway.

Regulations Governing the

7 Del.

Relevant and

Establishes minimum requirements

The interim remedy chosen is the installation of

Construction and Use of

Admin. C. §

Appropriate

governing the location, design, installation,

new public water line serving the residences in the

Wells

7301-3.6;



use, disinfection, modification, repair, and

Site. The remedy will comply with all relevant and



3.12.4;



sealing of all wells and associated

appropriate requirements to use, cap, and



3.12.9;



equipment as well as requirements for

abandon any private drinking water wells which



5.5.9;



public and private potable water wells.

will no longer be used following implementation.

-------


5.5.10;
5.11.5; 10.3





As well as any relevant and appropriate
requirements in the event a new public water well
is required in order to supply water to the Towns of
Blades public water supply.

Delaware Regulations
Governing the Allocation of
Water

7 Del.

Admin. C. §

7303-3.4;

5.5

Relevant and
Appropriate

Establishes authority for Delaware to
regulate the withdraw of groundwater for
public use.

The interim remedy chosen for implementation is
the installation of a public water supply line.
Groundwater modeling may be necessary to make
sure current Town of Blades public water supply
wells are adequate for additional residents.
Additionally, if modeling shows that existing supply
will not meet the capacity needs these regulations
provide for new water allocation permit
perimeters.

Delaware Air Quality
Management Regulations

7 Del.

Admin. C. §§
1103-1.6;
3.0; 11

Relevant and
Appropriate

The regulations establish the ambient air
quality and particulate emissions for the
state of Delaware.

The interim remedy will include excavation of the
water line areas. These regulations will apply to
any dust or emissions from construction vehicles.

Delaware Air Quality
Management Regulations

7 Del.

Admin. C. §
1106

Relevant and
Appropriate

The regulations establish particulate
emissions during construction and
material handling.

The interim remedy will include excavation of the
water line areas. These regulations will apply to
any dust or emissions from construction vehicles.

Delaware Division of
Transportation Solutions

2 Del.

Admin. C. §§
2400- 3.0 -
4.0.

Relevant and
Appropriate

Establishes Regulations within the State of
Delaware including policies and
procedures for adjusting, relocating, and

accommodating utility facilities and private
lines within the public right-of-way of
DelDOT-maintained highways and streets,
including any utility work related to
highway project construction in the right-
of-way of DelDOT-maintained streets and
highways.

The chosen interim remedy is the installation of a
public water line that will use the right of way in
public right of way.

Delaware Regulations
Governing Control of Water
Pollution

7 Del.

Admin. C. §
7201,

Subsections

Applicable

Contains water quality regulations for
discharging into surface and groundwater.

Applicable for potential discharge of treated
groundwater into surface water (dewater). Also
applicable for potential storm water runoff into
Morgan Branch or the Nanticoke River.

-------


7, 8, 9, 10,
11, 12, 13







Delaware Water Quality
Standards

7 Del.

Admin. C. §
7401,

Subsections
3-6, 8-10,
11.1, 11.2,
11.3, 11.4,
11.6, 12

Applicable

Standards are established in order to
regulate the discharge into state waters in
order to maintain the integrity of the
water.

Applicable because the groundwater management
system will most likely discharge to surface water
(the final discharge point will be determined in
design).

-------
APPENDIX C
RISK ASSESSMENT CALCULATIONS

-------
Human Health Risk Assessment
Table of Contents

ATTACHMENT 1: HUMAN HEALTH RISK ASSESSMENT DATA SETS

Table A1-1 Selection of Exposure Pathways
Table A1-2 Samples Used Within HHRA - Summary

ATTACHMENT 2: HUMAN HEALTH IDENTIFICATION OF CONSTITUENTS OF INTEREST

Table

A2-1

Table

A2-2

Table

A2-3

Table

A2-4

Table

A2-5

Table

A2-6

Table

A2-7

Table

A2-8

Table

A2-9

Table

A2-10

Table

A2-11

Table

A2-12

Table

A2-13

Table

A2-14

Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Occurrence, Distribution
OU2; Groundwater, Wei
Surrogate Toxicity Used

and Selection of Constituents of Interest (Direct Contact ¦
0124)

and Selection of Constituents of Interest (Direct Contact ¦
0155)

and Selection of Constituents of Interest (Direct Contact ¦
0170)

and Selection of Constituents of Interest (Direct Contact ¦
0173)

and Selection of Constituents of Interest (Direct Contact ¦
0176)

and Selection of Constituents of Interest (Direct Contact ¦
0182)

and Selection of Constituents of Interest (Direct Contact ¦
0197)

and Selection of Constituents of Interest (Direct Contact ¦
0212)

and Selection of Constituents of Interest (Direct Contact ¦
0275)

and Selection of Constituents of Interest (Direct Contact ¦

0500)

and Selection of Constituents of Interest (Direct Contact ¦

0501)

and Selection of Constituents of Interest (Direct Contact ¦
0510)

and Selection of Constituents of Interest (Direct Contact ¦
0527)

within Human Health Risk Assessment

ATTACHMENT 3: HUMAN HEALTH EXPOSURE ASSESSMENT CALCULATIONS
Human Health Exposure Point Concentration Summary

Table A3-1 Exposure Point Concentration Summary (Direct Contact - Groundwater)
Table A3-2 Exposure Point Concentration Summary (Vapor Intrusion - Groundwater)
Table A3-3 Residential VISL Model Input Values for Vapor Intrusion from Groundwater

ATTACHMENT 4:

Values Used for Daily Intake and Dermally Absorbed Dose Calculations: Reasonable Maximum
Exposure

Reasonable Maximum Exposure: Incidental Ingestion and Dermal Absorption of
Table A4-1 Groundwater

Reasonable Maximum Exposure: Inhalation of Vapors from Groundwater to Indoor Air
Table A4-2 | (Shower/Vapor Intrusion)

Page 1 of 5

-------
Human Health Risk Assessment
Table of Contents

Environmental Transport and Fate Models

Table A4-3 Dermal Worksheet for Groundwater (Potable Use)

Table A4-4 Modeled Groundwater-to-Vapor Concentrations while Showering

Lead Exposure Modeling Results

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results, Lead in Groundwater,
Table A4-5 Child Resident, Residential Well 0155 Tapwater Results

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results, Lead in Groundwater,
Table A4-6 Child Resident, Residential Well 0176 Tapwater Results

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results, Lead in Groundwater,
Table A4-7 Child Resident, Residential Well 0212 Tapwater Results

ATTACHMENTS: HUMAN HEALTH TOXICITY ASSESSMENT AND RISK CHARACTERIZATION
CALCULATIONS

Cancer and Non-Cancer Toxicity Data

Table A5-1
Table A5-2
Table A6-1
Table A6-2

Non-Cancer Toxicity Data - Oral/Dermal
Non-Cancer Toxicity Data - Inhalation
Cancer Toxicity Data - Oral/Dermal
Cancer Toxicity Data - Inhalation

Calculation of Chemical Cancer Risks and Non-Cancer Hazards: Reasonable Maximum

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Exposure

Table

A7-1

Table

A7-2

Table

A7-3

Table

A7-4

Table

A7-5

Table

A7-6

Table

A7-7

Table

A7-8

Table

A7-9

Table

A7-10

Table

A7-11

Table

A7-12

Table

A7-13

Table

A7-14

Table

A7-15

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

ntrusion); Reasonable Maximum Exposure (Well 0124)

ntrusion); Reasonable Maximum Exposure (Well 0124)

ntrusion); Reasonable Maximum Exposure (Well 0124)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0170)

ntrusion); Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0176)

Page 2 of 5

-------
Human Health Risk Assessment
Table of Contents

Table

A7-16

Table

A7-17

Table

A7-18

Table

A7-19

Table

A7-20

Table

A7-21

Table

A7-22

Table

A7-23

Table

A7-24

Table

A7-25

Table

A7-26

Table

A7-27

Table

A7-28

Table

A7-29

Table

A7-30

Table

A7-31

Table

A7-32

Table

A7-33

Table

A7-34

Table

A7-35

Table

A7-36

Table

A7-37

Table

A7-38

Table

A7-39

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

ntrusion); Reasonable Maximum Exposure (Well 0182)

ntrusion); Reasonable Maximum Exposure (Well 0182)

ntrusion); Reasonable Maximum Exposure (Well 0182)

ntrusion); Reasonable Maximum Exposure (Well 0197)

ntrusion); Reasonable Maximum Exposure (Well 0197)

ntrusion); Reasonable Maximum Exposure (Well 0197)

ntrusion); Reasonable Maximum Exposure (Well 0212)

ntrusion); Reasonable Maximum Exposure (Well 0212)

ntrusion); Reasonable Maximum Exposure (Well 0212)

ntrusion); Reasonable Maximum Exposure (Well 0275)

ntrusion); Reasonable Maximum Exposure (Well 0275)

ntrusion); Reasonable Maximum Exposure (Well 0275)

ntrusion); Reasonable Maximum Exposure (Well 0500)

ntrusion); Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0527)

Summary of Chemical Cancer Risks and Non-Cancer Hazards for Constituents of Interest:
Reasonable Maximum Exposure

Current/Future On-Sifr
Table A9-1 Groundwater (Vapor

Current/Future On-Sifr
Table A9-2 Groundwater (Vapor

e Resident (Child) - Groundwater, Groundwater (Potable Use),
ntrusion); Reasonable Maximum Exposure (Well 0124)
e Resident (Adult) - Groundwater, Groundwater (Potable Use),
ntrusion); Reasonable Maximum Exposure (Well 0124)

Page 3 of 5

-------
Human Health Risk Assessment
Table of Contents

Table

A9-3

Table

A9-4

Table

A9-5

Table

A9-6

Table

A9-7

Table

A9-8

Table

A9-9

Table

A9-10

Table

A9-11

Table

A9-12

Table

A9-13

Table

A9-14

Table

A9-15

Table

A9-16

Table

A9-17

Table

A9-18

Table

A9-19

Table

A9-20

Table

A9-21

Table

A9-22

Table

A9-23

Table

A9-24

Table

A9-25

Table

A9-26

Table

A9-27

Table

A9-28

Table

A9-29

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

Groundwater (Vapor

ntrusion); Reasonable Maximum Exposure (Well 0124)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0155)

ntrusion); Reasonable Maximum Exposure (Well 0170)

ntrusion); Reasonable Maximum Exposure (Well 0170)

ntrusion); Reasonable Maximum Exposure (Well 0170)

ntrusion); Reasonable Maximum Exposure (Well 0173)

ntrusion); Reasonable Maximum Exposure (Well 0173)

ntrusion); Reasonable Maximum Exposure (Well 0173)

ntrusion); Reasonable Maximum Exposure (Well 0176)

ntrusion); Reasonable Maximum Exposure (Well 0176)

ntrusion); Reasonable Maximum Exposure (Well 0176)

ntrusion); Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),

ntrusion); Reasonable Maximum Exposure (Well 0500)

Page 4 of 5

-------
Human Health Risk Assessment
Table of Contents

Table

A9-30

Table

A9-31

Table

A9-32

Table

A9-33

Table

A9-34

Table

A9-35

Table

A9-36

Table

A9-37

Table

A9-38

Table

A9-39

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0500)
Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0501)
Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0501)
Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0501)
Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0510)
Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0510)
Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0510)
Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0527)
Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0527)
Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use),
Groundwater (Vapor Intrusion); Reasonable Maximum Exposure (Well 0527)

Page 5 of 5

-------
Human Health Risk Assessment

This Page Intentionally Blank

AECOM

-------
Attachment 1
Human Health Risk Assessment Data Sets

-------
Human Health Risk Assessment

This Page Intentionally Blank

AECOM

-------
Table A1-1
Selection of Exposure Pathways
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario
Timeframe

Medium

Exposure
Medium

Exposure Point

Receptor Population

Receptor
Age

Exposure Route

Type ot
Analysis

Rationale for Selection or Exclusion of Exposure Pathway

















Receptor may ingest groundwater as a source of tap water.

Child

Quant

Receptor may ingest groundwater as a source of tap water.

Child/Adult

Quant

i ne cancer risK estimates tor tne aauit resiaent years; ana cnna resident (b years; are
added together (26 years) to address lifetime exposure to groundwater. The non-cancer
hazard evaluations are treated separately for child and adult resident.

OU2 Resident

Dermal

Adult

Quant

Receptor may come into contact with groundwater (tap water).

Child

Quant

Receptor may come into contact with groundwater (tap water).

Child/Adult

Quant

i ne cancer risK estimates tor tne aauit resiaent years; ana cnna resiaent (b years; are
added together (26 years) to address lifetime exposure to groundwater. The non-cancer
hazard evaluations are treated separately for child and adult resident.

Indoor Air

Groundwater at OU2

OU2 Resident

Inhalation

Adult

Quant

Receptor may inhale VOCs from groundwater via vapor intrusion into residence.

Child

Quant

Receptor may inhale VOCs from groundwater via vapor intrusion into residence.

Child/Adult

Quant

i ne cancer risK estimates tor tne aauit resiaent years; ana cnna resiaent (b years; are
added together (26 years) to address lifetime exposure to groundwater. The non-cancer
hazard evaluations are treated separately for child and adult resident.

Shower Air

Groundwater at OU2

OU2 Resident

Inhalation

Adult

Quant

Receptor may inhale vapors while showering since groundwater is used as a tap water
source.

Child

Quant

Receptor may inhale vapors while bathing since groundwater is used as a tap water
source.

Child/Adult

Quant

i ne cancer risK estimates tor tne aauit resiaent years; ana cnna resiaent (b years; are
added together (26 years) to address lifetime exposure to groundwater. The non-cancer
hazard evaluations are treated separately for child and adult resident.

Quant = Quantitative; VOC = volatile organic compound

-------
Table A1-2
Samples Used Within HHRA - Summary
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Medium

Exposure
Area

Sample
Location

Sample
Name

Type

Date

Vertical
Unit

Result Count

VOC

SVOC

PFAS

PCB

DIOX

TMET

CYANIDE

TOTAL

WP

OU2

0155

C0BF8

N

9/20/2021

-

55

67

4

2

1

21

1

151

WP

OU2

0510

C0BF6

N

9/20/2021

-

55

67

4

2

1

21

1

151

WP

OU2

0173

C0BG1

N

9/21/2021

-

55

67

4

2

1

21

1

151

WP

OU2

0176

C0BG2

N

9/21/2021

-

55

67

3

2

1

21

1

150

WP

OU2

0501

C0BH8

N

9/22/2021

-

54

19

4

2

1

21

1

102

WP

OU2

0124

C0BK1

N

9/27/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0182

C0BL8

N

9/29/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0197

C0BM1

N

9/30/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0275

C0BN3

N

10/5/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0500

C0BM9

N

10/5/2021

-

55

68

3

2

1

21

1

151

WP

OU2

0527

C0BN2

N

10/5/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0170

C0BN7

N

10/6/2021

-

55

68

4

2

1

21

1

152

WP

OU2

0212

C0BP1

N

10/7/2021

-

55

68

4

2

1

21

1

152

Notes:

FD = Field Duplicate Sample	PFAS = Perfluorinated Compounds

N = Primary Sample	PCB = Polychlorinated Biphenyls

WP = Potable Water	DIOX = Dioxins/Furans

VOC = Volatile Organic Compounds	TMET = Total Metals
SVOC = Semi-Volatile Organic Compounds

-------
Attachment 2
Human Health Risk-Based Screening Results

-------
Table A2-1

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0124)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0124

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

0.17

J

0.17

J

mq/l

1/1

100%

0.082-0.082

0.17

MDC

19



RSL

28.9

No

No

MDC < SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-1

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0124)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0124

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-1

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0124)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0124

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-1

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0124)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0124

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000051

J

0.000051

J

mq/l

1/1

100%

N/A

0.000051

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.002-0.002

0.002

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.00056

J

0.00056

J

mq/l

1/1

100%

0.002-0.002

0.00056

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.0058



0.0058



mq/l

1/1

100%

0.00039-0.00039

0.0058

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.011



0.011



mq/l

1/1

100%

0.00039-0.00039

0.011

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0012

J

0.0012

J

mq/l

1/1

100%

0.00039-0.00039

0.0012

MDC

0.006



RSL

No SL

No

No

MDC < SL

Total Metals

Aluminum



7429-90-5

130



130



mq/l

1/1

100%

4-4

130

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

480



480



mq/l

1/1

100%

1.9-1.9

480

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

2



2



mq/l

1/1

100%

0.17-0.17

2

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

0.16

J

0.16

J

mq/l

1/1

100%

0.14-0.14

0.16

MDC

0.18



RSL

No SL

No

No

MDC < SL

Calcium



7440-70-2

8400



8400



mq/l

1/1

100%

120-120

8400

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.51

J

0.51

J

mq/l

1/1

100%

0.32-0.32

0.51

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

30



30



mq/l

1/1

100%

0.19-0.19

30

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

250



250



mq/l

1/1

100%

0.4-0.4

250

MDC

80



RSL

No SL

No

Yes

MDC > SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

9.8

J-

9.8

J-

mq/l

1/1

100%

0.21 -0.21

9.8

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

190



190



mq/l

1/1

100%

0.17-0.17

190

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

8



8



mq/l

1/1

100%

0.2-0.2

8

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

140



140



mq/l

1/1

100%

1.6-1.6

140

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 4.6 J 4.6 J |jg/L 1/1 100% 2.6-2.6 4.6 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-1

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0124)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0124

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J- = The result is an estimated quantity, but the result may be biased low.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-2

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0155)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0155

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.88-0.88

0.88

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-2

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0155)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0155

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0052-0.0052

0.0052

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.96-0.96

0.96

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0063-0.0063

0.0063

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

CO
CO
I

CO
CO

3.3

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.66-0.66

0.66

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.5-4.5

4.5

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-2

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0155)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0155

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.83-0.83

0.83

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0058-0.0058

0.0058

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.01 -0.01

0.01

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.47-0.47

0.47

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.009-0.009

0.009

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.016-0.016

0.016

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0078-0.0078

0.0078

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0039-0.0039

0.0039

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.8-2.8

2.8

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.8-0.8

0.8

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.1 -3.1

3.1

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0051 -0.0051

0.0051

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0056-0.0056

0.0056

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.63-0.63

0.63

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0073-0.0073

0.0073

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

LO
CO
I

LO
CO

3.5

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.023-0.023

0.023

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0083-0.0083

0.0083

MDL

180

*

RSL

No SL

No

No

MDL< SL

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

-------
Table A2-2

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0155)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0155

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Pyrene V

129-00-0

N/A

N/A

mq/l

0/1 0%

0.013-0.013

0.013 MDL

12

RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

2.6E-10



2.6E-10



mq/l

1/1

100%

N/A

2.6E-10

MDC

0.00000012

*

RSL

3.61 E-05

No

No

MDC < SL

Total PCB Congener

V

TPCB_CON

0.00013

J

0.00013

J

mq/l

1/1

100%

N/A

0.00013

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0017-0.0017

0.0017

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

N/A



N/A



mq/l

0/1

0%

0.0017-0.0017

0.0017

MDL

0.039



RSL

No SL

No

No

MDL< SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.6



RSL

No SL

No

No

MDL< SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.00059

J

0.00059

J

mq/l

1/1

100%

0.00035-0.00035

0.00059

MDC

0.004



RSL

No SL

No

No

MDC < SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0012

J

0.0012

J

mq/l

1/1

100%

0.00035-0.00035

0.0012

MDC

0.006



RSL

No SL

No

No

MDC < SL

Total Metals

Aluminum



7429-90-5

180



180



mq/l

1/1

100%

4-4

180

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

0.38

J

0.38

J

mq/l

1/1

100%

0.33-0.33

0.38

MDC

0.052



RSL

No SL

No

Yes

MDC > SL

Barium



7440-39-3

1100



1100



mq/l

1/1

100%

1.9-1.9

1100

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

1.5



1.5



mq/l

1/1

100%

0.17-0.17

1.5

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

0.33

J

0.33

J

mq/l

1/1

100%

0.14-0.14

0.33

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

8700



8700



mq/l

1/1

100%

120-120

8700

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.73

J

0.73

J

mq/l

1/1

100%

0.32-0.32

0.73

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

15



15



mq/l

1/1

100%

0.19-0.19

15

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

140



140



mq/l

1/1

100%

"3-
O

I

o

140

MDC

80



RSL

No SL

No

Yes

MDC > SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

23



23



mq/l

1/1

100%

0.21 -0.21

23

MDC

15



RSL

No SL

No

Yes

MDC > SL

Manganese



7439-96-5

120



120



mq/l

1/1

100%

0.17-0.17

120

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

8.8

JB+

8.8

JB+

mq/l

1/1

100%

0.2-0.2

8.8

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

3.1

J

3.1

J

mq/l

1/1

100%

1.2-1.2

3.1

MDC

8.6



RSL

No SL

No

No

MDC < SL

Zinc



7440-66-6

270



270



mq/l

1/1

100%

1.6-1.6

270

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 4.8 J 4.8 J |jg/L 1/1 100% 2.6-2.6 4.8 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

CASRN = Chemical Abstracts Service Registry Number

-------
Table A2-2

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0155)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0155

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value
MCL = Maximum Contaminant Level
MDC = Maximum Detected Concentration
N/A = Not Applicable
ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-3

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0170)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0170

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

1.4



1.4



mq/l

1/1

100%

0.079-0.079

1.4

MDC

0.22



RSL

0.972

Yes

Yes

MDC > SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-3

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0170)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0170

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-3

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0170)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0170

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-3

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0170)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0170

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.00014

J

0.00014

J

mq/l

1/1

100%

N/A

0.00014

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

0.0029



0.0029



mq/l

1/1

100%

0.0018-0.0018

0.0029

MDC

0.0059



RSL

No SL

No

No

MDC < SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0064



0.0064



mq/l

1/1

100%

0.0018-0.0018

0.0064

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.31



0.31



mq/l

1/1

100%

0.0035-0.0035

0.31

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.26



0.26



mq/l

1/1

100%

0.0035-0.0035

0.26

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.015



0.015



mq/l

1/1

100%

0.00035-0.00035

0.015

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

110



110



mq/l

1/1

100%

4-4

110

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

69



69



mq/l

1/1

100%

1.9-1.9

69

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

0.34

J

0.34

J

mq/l

1/1

100%

0.17-0.17

0.34

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.18



RSL

No SL

No

No

MDL< SL

Calcium



7440-70-2

9500



9500



mq/l

1/1

100%

120-120

9500

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

6.6

J+

6.6

J+

mq/l

1/1

100%

0.32-0.32

6.6

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

5.87



5.87



mq/l

1/1

100%

5.9-5.9

5.87

MDC

0.035



RSL

No SL

No

Yes

MDC > SL

Cobalt



7440-48-4

6.5



6.5



mq/l

1/1

100%

0.19-0.19

6.5

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

63



63



mq/l

1/1

100%

"3-
O

I

o

63

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

2.5



2.5



mq/l

1/1

100%

0.21 -0.21

2.5

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

40

J+

40

J+

mq/l

1/1

100%

0.17-0.17

40

MDC

43



RSL

No SL

No

No

MDC < SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

53



53



mq/l

1/1

100%

0.2-0.2

53

MDC

39



RSL

No SL

No

Yes

MDC > SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

38



38



mq/l

1/1

100%

1.6-1.6

38

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 N/A N/A |jg/L 0/1 0% 2.6-2.6 2.6 MDL 0.15 RSL 20.1 No See DSA MDL > SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-3

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0170)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0170

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J+ = The result is an estimated quantity, but the result may be biased high.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-4

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0173)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0173

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.86-0.86

0.86

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-4

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0173)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0173

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0052-0.0052

0.0052

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.93-0.93

0.93

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0063-0.0063

0.0063

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

CM
CO
I

CM
CO

3.2

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.4-4.4

4.4

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-4

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0173)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0173

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

O
CO

I

o

CO

0.81

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0058-0.0058

0.0058

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.01 -0.01

0.01

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.46-0.46

0.46

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.009-0.009

0.009

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.016-0.016

0.016

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0078-0.0078

0.0078

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0039-0.0039

0.0039

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.8-2.8

2.8

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.78-0.78

0.78

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.3-1.3

1.3

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3-3

3

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0051 -0.0051

0.0051

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0056-0.0056

0.0056

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.5-1.5

1.5

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.61 -0.61

0.61

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0073-0.0073

0.0073

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.4-3.4

3.4

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.023-0.023

0.023

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0083-0.0083

0.0083

MDL

180

*

RSL

No SL

No

No

MDL< SL

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

580



RSL

No SL

No

No

MDL< SL

-------
Table A2-4

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0173)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0173

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Pyrene V

129-00-0

N/A

N/A

mq/l

0/1 0%

0.013-0.013

0.013 MDL

12

RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000049

J

0.000049

J

mq/l

1/1

100%

N/A

0.000049

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.00086

J

0.00086

J

mq/l

1/1

100%

0.0018-0.0018

0.00086

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.0078



0.0078



mq/l

1/1

100%

0.00035-0.00035

0.0078

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.024

J

0.024

J

mq/l

1/1

100%

0.00035-0.00035

0.024

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0023



0.0023



mq/l

1/1

100%

0.00035-0.00035

0.0023

MDC

0.006



RSL

No SL

No

No

MDC < SL

Total Metals

Aluminum



7429-90-5

85



85



mq/l

1/1

100%

4-4

85

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

430



430



mq/l

1/1

100%

1.9-1.9

430

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

1.1



1.1



mq/l

1/1

100%

0.17-0.17

1.1

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

0.16

J

0.16

J

mq/l

1/1

100%

0.14-0.14

0.16

MDC

0.18



RSL

No SL

No

No

MDC < SL

Calcium



7440-70-2

6800



6800



mq/l

1/1

100%

120-120

6800

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.63

J

0.63

J

mq/l

1/1

100%

0.32-0.32

0.63

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

22



22



mq/l

1/1

100%

0.19-0.19

22

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

60



60



mq/l

1/1

100%

"3-
O

I

o

60

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

2.9



2.9



mq/l

1/1

100%

0.21 -0.21

2.9

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

220



220



mq/l

1/1

100%

0.17-0.17

220

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

7.3

JB+

7.3

JB+

mq/l

1/1

100%

0.2-0.2

7.3

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

70



70



mq/l

1/1

100%

1.6-1.6

70

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 9.5 J 9.5 J |jg/L 1/1 100% 2.6-2.6 9.5 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

CASRN = Chemical Abstracts Service Registry Number

-------
Table A2-4

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0173)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0173

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value
MCL = Maximum Contaminant Level
MDC = Maximum Detected Concentration
N/A = Not Applicable
ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-5

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0176)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0176

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.86-0.86

0.86

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-5

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0176)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0176

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0052-0.0052

0.0052

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.93-0.93

0.93

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0063-0.0063

0.0063

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

CM
CO
I

CM
CO

3.2

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.4-4.4

4.4

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-5

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0176)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0176

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

O
CO

I

o

CO

0.81

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0058-0.0058

0.0058

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.01 -0.01

0.01

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.46-0.46

0.46

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.009-0.009

0.009

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.016-0.016

0.016

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0078-0.0078

0.0078

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0039-0.0039

0.0039

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.8-2.8

2.8

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.78-0.78

0.78

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.3-1.3

1.3

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3-3

3

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0051 -0.0051

0.0051

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0056-0.0056

0.0056

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.5-1.5

1.5

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.61 -0.61

0.61

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

0.017

JB

0.017

JB

mq/l

1/1

100%

0.0073-0.0073

0.017

MDC

0.12



RSL

6.29

No

No

MDC < SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.4-3.4

3.4

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.023-0.023

0.023

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0083-0.0083

0.0083

MDL

180

*

RSL

No SL

No

No

MDL< SL

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

580



RSL

No SL

No

No

MDL< SL

-------
Table A2-5

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0176)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0176

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Pyrene V

129-00-0

N/A

N/A

mq/l

0/1 0%

0.013-0.013

0.013 MDL

12

RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000043

J

0.000043

J

mq/l

1/1

100%

N/A

0.000043

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.039



RSL

No SL

No

No

MDL< SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

N/A



N/A



mq/l

0/1

0%

0.00036-0.00036

0.00036

MDL

0.6



RSL

No SL

No

No

MDL< SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

N/A



N/A



mq/l

0/1

0%

0.00036-0.00036

0.00036

MDL

0.004



RSL

No SL

No

No

MDL< SL

Perfluorooctanoic acid (PFOA)



335-67-1

N/A



N/A



mq/l

0/1

0%

0.00036-0.00036

0.00036

MDL

0.006



RSL

No SL

No

No

MDL< SL

Total Metals

Aluminum



7429-90-5

47



47



mq/l

1/1

100%

4-4

47

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

420



420



mq/l

1/1

100%

1.9-1.9

420

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

0.93

J

0.93

J

mq/l

1/1

100%

0.17-0.17

0.93

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

0.2

J

0.2

J

mq/l

1/1

100%

0.14-0.14

0.2

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

7800



7800



mq/l

1/1

100%

120-120

7800

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.61

J

0.61

J

mq/l

1/1

100%

0.32-0.32

0.61

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

14



14



mq/l

1/1

100%

0.19-0.19

14

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

70



70



mq/l

1/1

100%

"3-
O

I

o

70

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

320



320



mq/l

1/1

100%

54-54

320

MDC

1400



RSL

No SL

No

No

MDC < SL

Lead



7439-92-1

15



15



mq/l

1/1

100%

0.21 -0.21

15

MDC

15



RSL

No SL

No

Yes

MDC > SL

Manganese



7439-96-5

160



160



mq/l

1/1

100%

0.17-0.17

160

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

6.6

JB+

6.6

JB+

mq/l

1/1

100%

0.2-0.2

6.6

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

120



120



mq/l

1/1

100%

1.6-1.6

120

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 9 J 9 J |jg/L 1/1 100% 2.6-2.6 9 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

CASRN = Chemical Abstracts Service Registry Number

-------
Table A2-5

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0176)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0176

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value
MCL = Maximum Contaminant Level
MDC = Maximum Detected Concentration
N/A = Not Applicable
ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-6

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0182)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0182

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

0.069

J

0.069

J

mq/l

1/1

100%

0.058-0.058

0.069

MDC

2.8



RSL

9.09

No

No

MDC < SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

0.15

J

0.15

J

mq/l

1/1

100%

0.079-0.079

0.15

MDC

0.17



RSL

2.74

No

No

MDC < SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

0.14

J

0.14

J

mq/l

1/1

100%

0.079-0.079

0.14

MDC

0.22



RSL

0.972

No

No

MDC < SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-6

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0182)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0182

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

0.16

J

0.16

J

mq/l

1/1

100%

0.053-0.053

0.16

MDC

14



RSL

533

No

No

MDC < SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-6

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0182)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0182

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-6

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0182)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0182

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000036

J

0.000036

J

mq/l

1/1

100%

N/A

0.000036

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

0.0011

J

0.0011

J

mq/l

1/1

100%

0.0019-0.0019

0.0011

MDC

0.0059



RSL

No SL

No

No

MDC < SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0078



0.0078



mq/l

1/1

100%

0.0019-0.0019

0.0078

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.052



0.052



mq/l

1/1

100%

0.00038-0.00038

0.052

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.22



0.22



mq/l

1/1

100%

0.0019-0.0019

0.22

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.013



0.013



mq/l

1/1

100%

0.00038-0.00038

0.013

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

19

J

19

J

mq/l

1/1

100%

4-4

19

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

180



180



mq/l

1/1

100%

1.9-1.9

180

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

0.27

J

0.27

J

mq/l

1/1

100%

0.17-0.17

0.27

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.18



RSL

No SL

No

No

MDL< SL

Calcium



7440-70-2

11000



11000



mq/l

1/1

100%

120-120

11000

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

2200

*

RSL

No SL

No

No

MDL< SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

25



25



mq/l

1/1

100%

0.19-0.19

25

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

4.6



4.6



mq/l

1/1

100%

0.4-0.4

4.6

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

470



470



mq/l

1/1

100%

54-54

470

MDC

1400



RSL

No SL

No

No

MDC < SL

Lead



7439-92-1

0.73

J

0.73

J

mq/l

1/1

100%

0.21 -0.21

0.73

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

380



380



mq/l

1/1

100%

0.17-0.17

380

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

2.5



2.5



mq/l

1/1

100%

0.2-0.2

2.5

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

16



16



mq/l

1/1

100%

1.6-1.6

16

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 3.6 J 3.6 J |jg/L 1/1 100% 2.6-2.6 3.6 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-6

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0182)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0182

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number

COPC = Chemical of Potential Concern

DSA = Data Sensitivity Analysis

HAL = Health Advisory Level

J = Indicates an estimated value

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-7

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0197)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0197

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

0.51



0.51



mq/l

1/1

100%

0.079-0.079

0.51

MDC

0.22



RSL

0.972

No

Yes

MDC > SL

Chloromethane

V

74-87-3

0.19

J

0.19

J

mq/l

1/1

100%

0.082-0.082

0.19

MDC

19



RSL

28.9

No

No

MDC < SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-7

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0197)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0197

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

0.13

J

0.13

J

mq/l

1/1

100%

0.053-0.053

0.13

MDC

14



RSL

533

No

No

MDC < SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-7

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0197)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0197

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-7

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0197)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0197

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000041

J

0.000041

J

mq/l

1/1

100%

N/A

0.000041

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

0.0024



0.0024



mq/l

1/1

100%

0.0019-0.0019

0.0024

MDC

0.0059



RSL

No SL

No

No

MDC < SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0084



0.0084



mq/l

1/1

100%

0.0019-0.0019

0.0084

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.05



0.05



mq/l

1/1

100%

0.00037-0.00037

0.05

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.15



0.15



mq/l

1/1

100%

0.0019-0.0019

0.15

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.016



0.016



mq/l

1/1

100%

0.00037-0.00037

0.016

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

N/A



N/A



mq/l

0/1

0%

4-4

4

MDL

2000



RSL

No SL

No

No

MDL< SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

160



160



mq/l

1/1

100%

1.9-1.9

160

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

N/A



N/A



mq/l

0/1

0%

0.17-0.17

0.17

MDL

2.5



RSL

No SL

No

No

MDL< SL

Cadmium



7440-43-9

0.33

J

0.33

J

mq/l

1/1

100%

0.14-0.14

0.33

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

12000



12000



mq/l

1/1

100%

120-120

12000

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.46

J

0.46

J

mq/l

1/1

100%

0.32-0.32

0.46

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

13



13



mq/l

1/1

100%

0.19-0.19

13

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

17



17



mq/l

1/1

100%

0.4-0.4

17

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

0.47

J

0.47

J

mq/l

1/1

100%

0.21 -0.21

0.47

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

180



180



mq/l

1/1

100%

0.17-0.17

180

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

1.8



1.8



mq/l

1/1

100%

0.2-0.2

1.8

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

18



18



mq/l

1/1

100%

1.6-1.6

18

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 3.2 J 3.2 J |jg/L 1/1 100% 2.6-2.6 3.2 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-7

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0197)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0197

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number

COPC = Chemical of Potential Concern

DSA = Data Sensitivity Analysis

HAL = Health Advisory Level

J = Indicates an estimated value

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-8

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0212)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0212

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

0.28

J

0.28

J

mq/l

1/1

100%

0.079-0.079

0.28

MDC

0.22



RSL

0.972

No

Yes

MDC > SL

Chloromethane

V

74-87-3

0.24

J

0.24

J

mq/l

1/1

100%

0.082-0.082

0.24

MDC

19



RSL

28.9

No

No

MDC < SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-8

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0212)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0212

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-8

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0212)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0212

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-8

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0212)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0212

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000061

J

0.000061

J

mq/l

1/1

100%

N/A

0.000061

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

0.0034



0.0034



mq/l

1/1

100%

0.0019-0.0019

0.0034

MDC

0.0059



RSL

No SL

No

No

MDC < SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0024



0.0024



mq/l

1/1

100%

0.0019-0.0019

0.0024

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.0096



0.0096



mq/l

1/1

100%

0.00037-0.00037

0.0096

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.057



0.057



mq/l

1/1

100%

0.00037-0.00037

0.057

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.011



0.011



mq/l

1/1

100%

0.00037-0.00037

0.011

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

130



130



mq/l

1/1

100%

4-4

130

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

67



67



mq/l

1/1

100%

1.9-1.9

67

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

0.27

J

0.27

J

mq/l

1/1

100%

0.17-0.17

0.27

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.18



RSL

No SL

No

No

MDL< SL

Calcium



7440-70-2

7100



7100



mq/l

1/1

100%

120-120

7100

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.39

J

0.39

J

mq/l

1/1

100%

0.32-0.32

0.39

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

1.6



1.6



mq/l

1/1

100%

0.19-0.19

1.6

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

290



290



mq/l

1/1

100%

0.4-0.4

290

MDC

80



RSL

No SL

No

Yes

MDC > SL

Iron



7439-89-6

810



810



mq/l

1/1

100%

54-54

810

MDC

1400



RSL

No SL

No

No

MDC < SL

Lead



7439-92-1

16



16



mq/l

1/1

100%

0.21 -0.21

16

MDC

15



RSL

No SL

No

Yes

MDC > SL

Manganese



7439-96-5

24

J+

24

J+

mq/l

1/1

100%

0.17-0.17

24

MDC

43



RSL

No SL

No

No

MDC < SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

2.1



2.1



mq/l

1/1

100%

0.2-0.2

2.1

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

72



72



mq/l

1/1

100%

1.6-1.6

72

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 N/A N/A |jg/L 0/1 0% 2.6-2.6 2.6 MDL 0.15 RSL 20.1 No See DSA MDL > SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-8

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0212)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0212

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J+ = The result is an estimated quantity, but the result may be biased high.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-9

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0275)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0275

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-9

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0275)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0275

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

0.068

J

0.068

J

mq/l

1/1

100%

0.062-0.062

0.068

MDC

0.28



RSL

0.632

No

No

MDC < SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-9

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0275)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0275

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-9

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0275)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0275

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.00017

J

0.00017

J

mq/l

1/1

100%

N/A

0.00017

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0017-0.0017

0.0017

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0026



0.0026



mq/l

1/1

100%

0.0017-0.0017

0.0026

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.02



0.02



mq/l

1/1

100%

0.00035-0.00035

0.02

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.06



0.06



mq/l

1/1

100%

0.00035-0.00035

0.06

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0074



0.0074



mq/l

1/1

100%

0.00035-0.00035

0.0074

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

6.4

J

6.4

J

mq/l

1/1

100%

4-4

6.4

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

110



110



mq/l

1/1

100%

1.9-1.9

110

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

N/A



N/A



mq/l

0/1

0%

0.17-0.17

0.17

MDL

2.5



RSL

No SL

No

No

MDL< SL

Cadmium



7440-43-9

0.2

J

0.2

J

mq/l

1/1

100%

0.14-0.14

0.2

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

12000



12000



mq/l

1/1

100%

120-120

12000

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

2200

*

RSL

No SL

No

No

MDL< SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

1.8



1.8



mq/l

1/1

100%

0.19-0.19

1.8

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

63



63



mq/l

1/1

100%

0.4-0.4

63

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

2900



2900



mq/l

1/1

100%

54-54

2900

MDC

1400



RSL

No SL

No

Yes

MDC > SL

Lead



7439-92-1

2.5



2.5



mq/l

1/1

100%

0.21 -0.21

2.5

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

56

J+

56

J+

mq/l

1/1

100%

0.17-0.17

56

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

1.9



1.9



mq/l

1/1

100%

0.2-0.2

1.9

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

1.2

J

1.2

J

mq/l

1/1

100%

1.2-1.2

1.2

MDC

10



RSL

No SL

No

No

MDC < SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

180



180



mq/l

1/1

100%

1.6-1.6

180

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 N/A N/A |jg/L 0/1 0% 2.6-2.6 2.6 MDL 0.15 RSL 20.1 No See DSA MDL > SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-9

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0275)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0275

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J+ = The result is an estimated quantity, but the result may be biased high.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-10

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0500)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0500

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

0.11

J

0.11

J

mq/l

1/1

100%

0.082-0.082

0.11

MDC

19



RSL

28.9

No

No

MDC < SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-10

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0500)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0500

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

0.36

J

0.36

J

mq/l

1/1

100%

0.053-0.053

0.36

MDC

14



RSL

533

No

No

MDC < SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-10

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0500)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0500

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-10

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0500)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0500

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000082

J

0.000082

J

mq/l

1/1

100%

N/A

0.000082

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.039



RSL

No SL

No

No

MDL< SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.6



RSL

No SL

No

No

MDL< SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.004



RSL

No SL

No

No

MDL< SL

Perfluorooctanoic acid (PFOA)



335-67-1

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.006



RSL

No SL

No

No

MDL< SL

Total Metals

Aluminum



7429-90-5

110



110



mq/l

1/1

100%

4-4

110

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

690



690



mq/l

1/1

100%

1.9-1.9

690

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

3.6



3.6



mq/l

1/1

100%

0.17-0.17

3.6

MDC

2.5



RSL

No SL

No

Yes

MDC > SL

Cadmium



7440-43-9

0.44

J

0.44

J

mq/l

1/1

100%

0.14-0.14

0.44

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

8600



8600



mq/l

1/1

100%

120-120

8600

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

2200

*

RSL

No SL

No

No

MDL< SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

26



26



mq/l

1/1

100%

0.19-0.19

26

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

53



53



mq/l

1/1

100%

0.4-0.4

53

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

2.6



2.6



mq/l

1/1

100%

0.21 -0.21

2.6

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

180

J+

180

J+

mq/l

1/1

100%

0.17-0.17

180

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

13



13



mq/l

1/1

100%

0.2-0.2

13

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

220



220



mq/l

1/1

100%

1.6-1.6

220

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 N/A N/A |jg/L 0/1 0% 2.6-2.6 2.6 MDL 0.15 RSL 20.1 No See DSA MDL > SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-10

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0500)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0500

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J+ = The result is an estimated quantity, but the result may be biased high.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-11

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0501)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0501

Chemical(1)

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6>

Source

visl(4)

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-T richloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-T richlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

0.96



0.96



mq/l

1/1

100%

0.079-0.079

0.96

MDC

0.22



RSL

0.972

No

Yes

MDC > SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

-------
Table A2-11

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0501)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0501

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

O

I

o

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

O

I

o

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

0.025

JB

0.025

JB

mq/l

1/1

100%

0.014-0.014

0.025

MDC

12



RSL

No SL

No

No

MDC < SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.00004

J

0.00004

J

mq/l

1/1

100%

N/A

0.00004

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA) 375-95-1 0.0036 0.0036 |jg/L 1/1 100% 0.0018-0.0018 0.0036 MDC 0.0059 RSL No SL No No MDC
-------
Table A2-11

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0501)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0501

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.012



0.012



mq/l

1/1

100%

0.0018-0.0018

0.012

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.11



0.11



mq/l

1/1

100%

0.0018-0.0018

0.11

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.13



0.13



mq/l

1/1

100%

0.0018-0.0018

0.13

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.017



0.017



mq/l

1/1

100%

0.00035-0.00035

0.017

MDC

0.006



RSL

No SL

No

Yes

MDC > SL

Total Metals

Aluminum



7429-90-5

4

J

4

J

mq/l

1/1

100%

4-4

4

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

200



200



mq/l

1/1

100%

1.9-1.9

200

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

N/A



N/A



mq/l

0/1

0%

0.17-0.17

0.17

MDL

2.5



RSL

No SL

No

No

MDL< SL

Cadmium



7440-43-9

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.18



RSL

No SL

No

No

MDL< SL

Calcium



7440-70-2

15000



15000



mq/l

1/1

100%

120-120

15000

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

1.7

J

1.7

J

mq/l

1/1

100%

0.32-0.32

1.7

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

16



16



mq/l

1/1

100%

0.19-0.19

16

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

3.3



3.3



mq/l

1/1

100%

0.4-0.4

3.3

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

190

J

190

J

mq/l

1/1

100%

54-54

190

MDC

1400



RSL

No SL

No

No

MDC < SL

Lead



7439-92-1

0.22

J

0.22

J

mq/l

1/1

100%

0.21 -0.21

0.22

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

260



260



mq/l

1/1

100%

0.17-0.17

260

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

2.3

JB+

2.3

JB+

mq/l

1/1

100%

0.2-0.2

2.3

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

3.2

J

3.2

J

mq/l

1/1

100%

1.2-1.2

3.2

MDC

8.6



RSL

No SL

No

No

MDC < SL

Zinc



7440-66-6

34



34



mq/l

1/1

100%

1.6-1.6

34

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide

V

57-12-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.15

RSL

20.1

No

See DSA

MDL > SL

Notes:

% = Percent
AL = Action Level

CASRN = Chemical Abstracts Service Registry Number

COPC = Chemical of Potential Concern

DSA = Data Sensitivity Analysis

HAL = Health Advisory Level

J = Indicates an estimated value

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

-------
Table A2-11

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0501)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0501

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-12

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0510)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0510

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.86-0.86

0.86

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-12

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0510)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0510

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0052-0.0052

0.0052

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.93-0.93

0.93

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0063-0.0063

0.0063

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

CM
CO
I

CM
CO

3.2

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.4-4.4

4.4

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-12

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0510)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0510

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

O
CO

I

o

CO

0.81

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0058-0.0058

0.0058

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.01 -0.01

0.01

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.46-0.46

0.46

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.009-0.009

0.009

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.016-0.016

0.016

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0078-0.0078

0.0078

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0039-0.0039

0.0039

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.8-2.8

2.8

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.78-0.78

0.78

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.3-1.3

1.3

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3-3

3

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0051 -0.0051

0.0051

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0056-0.0056

0.0056

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.5-1.5

1.5

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.61 -0.61

0.61

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0073-0.0073

0.0073

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.4-3.4

3.4

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.023-0.023

0.023

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0083-0.0083

0.0083

MDL

180

*

RSL

No SL

No

No

MDL< SL

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

580



RSL

No SL

No

No

MDL< SL

-------
Table A2-12

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0510)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0510

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Pyrene V

129-00-0

N/A

N/A

mq/l

0/1 0%

0.013-0.013

0.013 MDL

12

RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

5.8E-10



5.8E-10



mq/l

1/1

100%

N/A

5.8E-10

MDC

0.00000012

*

RSL

3.61 E-05

No

No

MDC < SL

Total PCB Congener

V

TPCB_CON

0.000044

J

0.000044

J

mq/l

1/1

100%

N/A

0.000044

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.039



RSL

No SL

No

No

MDL< SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.6



RSL

No SL

No

No

MDL< SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

N/A



N/A



mq/l

0/1

0%

0.00035-0.00035

0.00035

MDL

0.004



RSL

No SL

No

No

MDL< SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0011

J

0.0011

J

mq/l

1/1

100%

0.00035-0.00035

0.0011

MDC

0.006



RSL

No SL

No

No

MDC < SL

Total Metals

Aluminum



7429-90-5

90



90



mq/l

1/1

100%

4-4

90

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

1300



1300



mq/l

1/1

100%

1.9-1.9

1300

MDC

380



RSL

No SL

No

Yes

MDC > SL

Beryllium



7440-41-7

1.6



1.6



mq/l

1/1

100%

0.17-0.17

1.6

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

0.39

J

0.39

J

mq/l

1/1

100%

0.14-0.14

0.39

MDC

0.18



RSL

No SL

No

Yes

MDC > SL

Calcium



7440-70-2

9100



9100



mq/l

1/1

100%

120-120

9100

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.69

J

0.69

J

mq/l

1/1

100%

0.32-0.32

0.69

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

20



20



mq/l

1/1

100%

0.19-0.19

20

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

100



100



mq/l

1/1

100%

"3-
O

I

o

100

MDC

80



RSL

No SL

No

Yes

MDC > SL

Iron



7439-89-6

N/A



N/A



mq/l

0/1

0%

54-54

54

MDL

1400



RSL

No SL

No

No

MDL< SL

Lead



7439-92-1

5.6



5.6



mq/l

1/1

100%

0.21 -0.21

5.6

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

140



140



mq/l

1/1

100%

0.17-0.17

140

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

9.6

JB+

9.6

JB+

mq/l

1/1

100%

0.2-0.2

9.6

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

3.1

J

3.1

J

mq/l

1/1

100%

1.2-1.2

3.1

MDC

8.6



RSL

No SL

No

No

MDC < SL

Zinc



7440-66-6

69



69



mq/l

1/1

100%

1.6-1.6

69

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 11 11 |jg/L 1/1 100% 2.6-2.6 11 MDC 0.15 RSL 20.1 No Yes MDC>SL

Notes:

% = Percent
AL = Action Level

CASRN = Chemical Abstracts Service Registry Number

-------
Table A2-12

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0510)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0510

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value
MCL = Maximum Contaminant Level
MDC = Maximum Detected Concentration
N/A = Not Applicable
ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-13

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0527)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0527

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Volatile Organic Compounds (VOCs)

1,1,1-Trichloroethane

V

71-55-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

800



RSL

893

No

No

MDL< SL

1,1,2,2-Tetrachloroethane

V

79-34-5

N/A



N/A



mq/l

0/1

0%

0.05-0.05

0.05

MDL

0.076



RSL

4.18

No

No

MDL< SL

1,1,2-Trichloroethane

V

79-00-5

N/A



N/A



mq/l

0/1

0%

0.042-0.042

0.042

MDL

0.041



RSL

0.779

No

See DSA

MDL > SL

1,1,2-Trichlorotrifluoroethane (Freon 113)

V

76-13-1

N/A



N/A



mq/l

0/1

0%

0.099-0.099

0.099

MDL

1000



RSL

28.5

No

No

MDL< SL

1,1-Dichloroethane

V

75-34-3

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

2.8



RSL

9.09

No

No

MDL< SL

1,1-Dichloroethene

V

75-35-4

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

28



RSL

22.7

No

No

MDL< SL

1,2,3-Trichlorobenzene

V

87-61-6

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

0.7



RSL

No SL

No

No

MDL< SL

1,2,3-Trichloropropane

V

96-18-4

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

0.00075



RSL

2.89

No

See DSA

MDL > SL

1,2,4-Trichlorobenzene

V

120-82-1

N/A



N/A



mq/l

0/1

0%

0.068-0.068

0.068

MDL

0.4



RSL

4.97

No

No

MDL< SL

1,2,4-Trimethylbenzene

V

95-63-6

N/A



N/A



mq/l

0/1

0%

0.051 -0.051

0.051

MDL

5.6



RSL

33

No

No

MDL< SL

1,2-Dibromo-3-chloropropane

V

96-12-8

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.00033



RSL

0.0381

See DSA

See DSA

MDL > SL

1,2-Dibromoethane

V

106-93-4

N/A



N/A



mq/l

0/1

0%

0.052-0.052

0.052

MDL

0.0075



RSL

0.221

No

See DSA

MDL > SL

1,2-Dichlorobenzene

V

95-50-1

N/A



N/A



mq/l

0/1

0%

0.045-0.045

0.045

MDL

30



RSL

351

No

No

MDL< SL

1,2-Dichloroethane

V

107-06-2

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.17



RSL

2.74

No

No

MDL< SL

1,2-Dichloropropane

V

78-87-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.82



RSL

4.44

No

No

MDL< SL

1,3,5-Trimethylbenzene

V

108-67-8

N/A



N/A



mq/l

0/1

0%

0.067-0.067

0.067

MDL

6



RSL

23.2

No

No

MDL< SL

1,3-Dichlorobenzene

V

541-73-1

N/A



N/A



mq/l

0/1

0%

0.071 -0.071

0.071

MDL

30

*

RSL

351

No

No

MDL< SL

1,4-Dichlorobenzene

V

106-46-7

N/A



N/A



mq/l

0/1

0%

0.047-0.047

0.047

MDL

0.48



RSL

3.42

No

No

MDL< SL

1,4-Dioxane

V

123-91-1

N/A



N/A



mq/l

0/1

0%

0.9-0.9

0.9

MDL

0.46



RSL

3570

No

See DSA

MDL > SL

2-Butanone (MEK)

V

78-93-3

N/A



N/A



mq/l

0/1

0%

lo
I

lo

1.5

MDL

560



RSL

274000

No

No

MDL< SL

2-Hexanone

V

591-78-6

N/A



N/A



mq/l

0/1

0%

0.68-0.68

0.68

MDL

3.8



RSL

1060

No

No

MDL< SL

4-Methyl-2-pentanone (MIBK)

V

108-10-1

N/A



N/A



mq/l

0/1

0%

O
I

o

0.71

MDL

630



RSL

70200

No

No

MDL< SL

Acetone

V

67-64-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

1800



RSL

No SL

No

No

MDL< SL

Benzene

V

71-43-2

N/A



N/A



mq/l

0/1

0%

0.085-0.085

0.085

MDL

0.46



RSL

1.92

No

No

MDL< SL

Bromochloromethane

V

74-97-5

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

8.3



RSL

83.9

No

No

MDL< SL

Bromodichloromethane

V

75-27-4

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.13



RSL

1.08

No

No

MDL< SL

Bromoform

V

75-25-2

N/A



N/A



mq/l

0/1

0%

0.095-0.095

0.095

MDL

3.3



RSL

152

No

No

MDL< SL

Bromomethane

V

74-83-9

N/A



N/A



mq/l

0/1

0%

0.058-0.058

0.058

MDL

0.75



RSL

1.98

No

No

MDL< SL

Carbon disulfide

V

75-15-0

N/A



N/A



mq/l

0/1

0%

0.092-0.092

0.092

MDL

81



RSL

145

No

No

MDL< SL

Carbon tetrachloride

V

56-23-5

N/A



N/A



mq/l

0/1

0%

0.086-0.086

0.086

MDL

0.46



RSL

0.499

No

No

MDL< SL

Chlorobenzene

V

108-90-7

N/A



N/A



mq/l

0/1

0%

0.064-0.064

0.064

MDL

7.8



RSL

51.9

No

No

MDL< SL

Chloroethane

V

75-00-3

N/A



N/A



mq/l

0/1

0%

0.074-0.074

0.074

MDL

830



RSL

1050

No

No

MDL< SL

Chloroform

V

67-66-3

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

0.22



RSL

0.972

No

No

MDL< SL

Chloromethane

V

74-87-3

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

19



RSL

28.9

No

No

MDL< SL

cis-1,2-Dichloroethene

V

156-59-2

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

3.6



RSL

No SL

No

No

MDL< SL

cis-1,3-Dichloropropene

V

10061-01-5

N/A



N/A



mq/l

0/1

0%

0.069-0.069

0.069

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Cyclohexane

V

110-82-7

N/A



N/A



mq/l

0/1

0%

0.065-0.065

0.065

MDL

1300



RSL

123

No

No

MDL< SL

Dibromochloromethane

V

124-48-1

N/A



N/A



mq/l

0/1

0%

0.073-0.073

0.073

MDL

0.87



RSL

No SL

No

No

MDL< SL

Dichlorodifluoromethane

V

75-71-8

N/A



N/A



mq/l

0/1

0%

0.12-0.12

0.12

MDL

20



RSL

0.815

No

No

MDL< SL

Ethylbenzene

V

100-41-4

N/A



N/A



mq/l

0/1

0%

0.079-0.079

0.079

MDL

1.5



RSL

4.45

No

No

MDL< SL

-------
Table A2-13

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0527)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0527

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Isopropylbenzene

V

98-82-8

N/A



N/A



mq/l

0/1

0%

0.076-0.076

0.076

MDL

45



RSL

121

No

No

MDL< SL

m,p-Xylene

V

179601-23-1

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

19

*

RSL

45.5

No

No

MDL< SL

Methyl Acetate

V

79-20-9

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

2000



RSL

No SL

No

No

MDL< SL

Methyl Tert Butyl Ether

V

1634-04-4

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

14



RSL

533

No

No

MDL< SL

Methylcyclohexane

V

108-87-2

N/A



N/A



mq/l

0/1

0%

0.08-0.08

0.08

MDL

1300

*

RSL

123

No

No

MDL< SL

Methylene chloride

V

75-09-2

N/A



N/A



mq/l

0/1

0%

0.053-0.053

0.053

MDL

11



RSL

555

No

No

MDL< SL

o-Xylene

V

95-47-6

N/A



N/A



mq/l

0/1

0%

0.075-0.075

0.075

MDL

19



RSL

63.3

No

No

MDL< SL

Styrene

V

100-42-5

N/A



N/A



mq/l

0/1

0%

0.082-0.082

0.082

MDL

120



RSL

1210

No

No

MDL< SL

Tetrachloroethene

V

127-18-4

N/A



N/A



mq/l

0/1

0%

0.083-0.083

0.083

MDL

4.1



RSL

7.25

No

No

MDL< SL

Toluene

V

108-88-3

N/A



N/A



mq/l

0/1

0%

0.077-0.077

0.077

MDL

110



RSL

2390

No

No

MDL< SL

trans-1,2-Dichloroethene

V

156-60-5

N/A



N/A



mq/l

0/1

0%

0.081 -0.081

0.081

MDL

6.8



RSL

12.9

No

No

MDL< SL

trans-1,3-Dichloropropene

V

10061-02-6

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.47

*

RSL

6.04

No

No

MDL< SL

Trichloroethene

V

79-01-6

N/A



N/A



mq/l

0/1

0%

0.062-0.062

0.062

MDL

0.28



RSL

0.632

No

No

MDL< SL

Trichlorofluoromethane

V

75-69-4

N/A



N/A



mq/l

0/1

0%

0.11 -0.11

0.11

MDL

520



RSL

No SL

No

No

MDL< SL

Vinyl chloride

V

75-01-4

N/A



N/A



mq/l

0/1

0%

0.07-0.07

0.07

MDL

0.019



RSL

0.164

No

See DSA

MDL > SL

Semi-Volatile Organic Compounds (SVOCs)

1,1 '-Biphenyl

V

92-52-4

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.083



RSL

4.71

No

See DSA

MDL > SL

1,2,4,5-Tetrachlorobenzene

V

95-94-3

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.017



RSL

No SL

No

See DSA

MDL > SL

1-Methylnaphthalene

V

90-12-0

N/A



N/A



mq/l

0/1

0%

0.0055-0.0055

0.0055

MDL

1.1



RSL

No SL

No

No

MDL< SL

2,3,4,6-Tetrachlorophenol



58-90-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

24



RSL

No SL

No

No

MDL< SL

2,4,5-Trichlorophenol



95-95-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

120



RSL

No SL

No

No

MDL< SL

2,4,6-Trichlorophenol



88-06-2

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

1.2



RSL

No SL

No

See DSA

MDL > SL

2,4-Dichlorophenol



120-83-2

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4.6



RSL

No SL

No

No

MDL< SL

2,4-Dimethylphenol



105-67-9

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

36



RSL

No SL

No

No

MDL< SL

2,4-Dinitrophenol



51-28-5

N/A



N/A



mq/l

0/1

0%

0.98-0.98

0.98

MDL

3.9



RSL

No SL

No

No

MDL< SL

2,4-Dinitrotoluene



121-14-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.24



RSL

No SL

No

See DSA

MDL > SL

2,6-Dinitrotoluene



606-20-2

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.049



RSL

No SL

No

See DSA

MDL > SL

2-Chloronaphthalene

V

91-58-7

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

75



RSL

No SL

No

No

MDL< SL

2-Chlorophenol

V

95-57-8

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

9.1



RSL

No SL

No

No

MDL< SL

2-Methylnaphthalene

V

91-57-6

N/A



N/A



mq/l

0/1

0%

0.0066-0.0066

0.0066

MDL

3.6



RSL

No SL

No

No

MDL< SL

2-Methylphenol



95-48-7

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

93



RSL

No SL

No

No

MDL< SL

2-Nitroaniline



88-74-4

N/A



N/A



mq/l

0/1

0%

"3-

oo
I

oo

3.4

MDL

19



RSL

No SL

No

No

MDL< SL

2-Nitrophenol



88-75-5

N/A



N/A



mq/l

0/1

0%

2.7-2.7

2.7

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

3,3'-Dichlorobenzidine



91-94-1

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.13



RSL

No SL

No

See DSA

MDL > SL

3-Nitroaniline



99-09-2

N/A



N/A



mq/l

0/1

0%

0.67-0.67

0.67

MDL

19

*

RSL

No SL

No

No

MDL< SL

4,6-Dinitro-o-cresol



534-52-1

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.15



RSL

No SL

No

See DSA

MDL > SL

4-Bromophenyl phenyl ether

V

101-55-3

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Chloro-3-methyl phenol



59-50-7

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

140



RSL

No SL

No

No

MDL< SL

4-Chloroaniline



106-47-8

N/A



N/A



mq/l

0/1

0%

4.6-4.6

4.6

MDL

0.37



RSL

No SL

No

See DSA

MDL > SL

4-Chlorophenyl phenyl ether

V

7005-72-3

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

4

*

RSL

No SL

No

No

MDL< SL

4-Methylphenol



106-44-5

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

37



RSL

No SL

No

No

MDL< SL

-------
Table A2-13

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0527)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0527

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

4-Nitroaniline



100-01-6

N/A



N/A



mq/l

0/1

0%

0.85-0.85

0.85

MDL

3.8



RSL

No SL

No

No

MDL< SL

4-Nitrophenol



100-02-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.2

*

RSL

No SL

No

See DSA

MDL > SL

Acenaphthene

V

83-32-9

N/A



N/A



mq/l

0/1

0%

0.0061 -0.0061

0.0061

MDL

53



RSL

No SL

No

No

MDL< SL

Acenaphthylene

V

208-96-8

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

53

*

RSL

No SL

No

No

MDL< SL

Acetophenone

V

98-86-2

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

190



RSL

No SL

No

No

MDL< SL

Anthracene

V

120-12-7

N/A



N/A



mq/l

0/1

0%

0.011 -0.011

0.011

MDL

180



RSL

No SL

No

No

MDL< SL

Atrazine



1912-24-9

N/A



N/A



mq/l

0/1

0%

0.48-0.48

0.48

MDL

0.3



RSL

No SL

No

See DSA

MDL > SL

Benzaldehyde

V

100-52-7

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

19



RSL

No SL

No

No

MDL< SL

Benzo(a)anthracene

V

56-55-3

N/A



N/A



mq/l

0/1

0%

0.0094-0.0094

0.0094

MDL

0.03



RSL

62.3

No

No

MDL< SL

Benzo(a)pyrene



50-32-8

N/A



N/A



mq/l

0/1

0%

0.017-0.017

0.017

MDL

0.025



RSL

No SL

No

No

MDL< SL

Benzo(b)fluoranthene



205-99-2

N/A



N/A



mq/l

0/1

0%

0.0082-0.0082

0.0082

MDL

0.25



RSL

No SL

No

No

MDL< SL

Benzo(g,h,i)perylene

V

191-24-2

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

12

*

RSL

No SL

No

No

MDL< SL

Benzo(k)fluoranthene



207-08-9

N/A



N/A



mq/l

0/1

0%

0.0041 -0.0041

0.0041

MDL

2.5



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethoxy)methane



111-91-1

N/A



N/A



mq/l

0/1

0%

2.9-2.9

2.9

MDL

5.9



RSL

No SL

No

No

MDL< SL

bis(2-Chloroethyl)ether

V

111-44-4

N/A



N/A



mq/l

0/1

0%

2.1 -2.1

2.1

MDL

0.014



RSL

17

No

See DSA

MDL > SL

bis(2-Chloroisopropyl)ether

V

108-60-1

N/A



N/A



mq/l

0/1

0%

2.3-2.3

2.3

MDL

71



RSL

No SL

No

No

MDL< SL

bis(2-Ethylhexyl)phthalate



117-81-7

N/A



N/A



mq/l

0/1

0%

0.82-0.82

0.82

MDL

5.6



RSL

No SL

No

No

MDL< SL

Butyl benzyl phthalate



85-68-7

N/A



N/A



mq/l

0/1

0%

1.4-1.4

1.4

MDL

16



RSL

No SL

No

No

MDL< SL

Caprolactam



105-60-2

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

990



RSL

No SL

No

No

MDL< SL

Carbazole

V

86-74-8

N/A



N/A



mq/l

0/1

0%

3.2-3.2

3.2

MDL

29

*

RSL

No SL

No

No

MDL< SL

Chrysene



218-01-9

N/A



N/A



mq/l

0/1

0%

0.0054-0.0054

0.0054

MDL

25



RSL

No SL

No

No

MDL< SL

Dibenzo(a, h)anthracene



53-70-3

N/A



N/A



mq/l

0/1

0%

0.0059-0.0059

0.0059

MDL

0.025



RSL

No SL

No

No

MDL< SL

Dibenzofuran

V

132-64-9

N/A



N/A



mq/l

0/1

0%

2.2-2.2

2.2

MDL

0.79



RSL

No SL

No

See DSA

MDL > SL

Diethyl phthalate



84-66-2

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500



RSL

No SL

No

No

MDL< SL

Dimethyl phthalate



131-11-3

N/A



N/A



mq/l

0/1

0%

2-2

2

MDL

1500

*

RSL

No SL

No

No

MDL< SL

Di-n-butyl phthalate



84-74-2

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

90



RSL

No SL

No

No

MDL< SL

Di-n-octyl phthalate



117-84-0

N/A



N/A



mq/l

0/1

0%

0.64-0.64

0.64

MDL

20



RSL

No SL

No

No

MDL< SL

Fluoranthene



206-44-0

N/A



N/A



mq/l

0/1

0%

0.012-0.012

0.012

MDL

80



RSL

No SL

No

No

MDL< SL

Fluorene

V

86-73-7

N/A



N/A



mq/l

0/1

0%

0.0072-0.0072

0.0072

MDL

29



RSL

No SL

No

No

MDL< SL

Hexachlorobenzene

V

118-74-1

N/A



N/A



mq/l

0/1

0%

1.9-1.9

1.9

MDL

0.0098



RSL

0.133

See DSA

See DSA

MDL > SL

Hexachlorobutadiene

V

87-68-3

N/A



N/A



mq/l

0/1

0%

1.7-1.7

1.7

MDL

0.14



RSL

0.414

See DSA

See DSA

MDL > SL

Hexachlorocyclopentadiene

V

77-47-4

N/A



N/A



mq/l

0/1

0%

1.6-1.6

1.6

MDL

0.041



RSL

0.0786

See DSA

See DSA

MDL > SL

Hexachloroethane

V

67-72-1

N/A



N/A



mq/l

0/1

0%

2.6-2.6

2.6

MDL

0.33



RSL

2.29

See DSA

See DSA

MDL > SL

lndeno(1,2,3-cd)pyrene



193-39-5

N/A



N/A



mq/l

0/1

0%

0.0069-0.0069

0.0069

MDL

0.25



RSL

No SL

No

No

MDL< SL

Isophorone



78-59-1

N/A



N/A



mq/l

0/1

0%

1.8-1.8

1.8

MDL

78



RSL

No SL

No

No

MDL< SL

Naphthalene

V

91-20-3

N/A



N/A



mq/l

0/1

0%

0.0077-0.0077

0.0077

MDL

0.12



RSL

6.29

No

No

MDL< SL

Nitrobenzene

V

98-95-3

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

0.14



RSL

99.3

No

See DSA

MDL > SL

N-Nitroso-di-n-propylamine



621-64-7

N/A



N/A



mq/l

0/1

0%

2.4-2.4

2.4

MDL

0.011



RSL

No SL

No

See DSA

MDL > SL

N-Nitrosodiphenylamine



86-30-6

N/A



N/A



mq/l

0/1

0%

3.6-3.6

3.6

MDL

12



RSL

No SL

No

No

MDL< SL

Pentachlorophenol



87-86-5

N/A



N/A



mq/l

0/1

0%

0.024-0.024

0.024

MDL

0.041



RSL

No SL

No

No

MDL< SL

Phenanthrene

V

85-01-8

N/A



N/A



mq/l

0/1

0%

0.0087-0.0087

0.0087

MDL

180

*

RSL

No SL

No

No

MDL< SL

-------
Table A2-13

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0527)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0527

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

Phenol



108-95-2

N/A



N/A



mq/l

0/1

0%

2.5-2.5

2.5

MDL

580



RSL

No SL

No

No

MDL< SL

Pyrene

V

129-00-0

N/A



N/A



mq/l

0/1

0%

0.014-0.014

0.014

MDL

12



RSL

No SL

No

No

MDL< SL

DIOX

Total PCDD/F TEQ (Mammal) V TEQ-M-DF N/A N/A |jg/L 0/1 0% N/A N/A - 0.00000012 * RSL 3.61 E-05 No No No values for dioxin TEQ

PCB

Total PCB TEQ (Mammal)

V

TEQ-M-PCB

N/A



N/A



mq/l

0/1

0%

N/A

N/A

-

0.00000012

*

RSL

3.61 E-05

No

No

No values for dioxin TEQ

Total PCB Congener

V

TPCB_CON

0.000071

J

0.000071

J

mq/l

1/1

100%

N/A

0.000071

MDC

0.044

*

RSL

1.65

No

No

MDC < SL

Perfluorinated Compounds

Perfluorononanoic acid (PFNA)



375-95-1

N/A



N/A



mq/l

0/1

0%

0.0018-0.0018

0.0018

MDL

0.0059



RSL

No SL

No

No

MDL< SL

Perfluorohexanesulfonic acid (PFHxS)



355-46-4

0.0017

J

0.0017

J

mq/l

1/1

100%

0.0018-0.0018

0.0017

MDC

0.039



RSL

No SL

No

No

MDC < SL

Perfluorobutanesulfonic acid (PFBS)



375-73-5

0.012



0.012



mq/l

1/1

100%

0.00037-0.00037

0.012

MDC

0.6



RSL

No SL

No

No

MDC < SL

Perfluorooctanesulfonic acid (PFOS)



1763-23-1

0.065



0.065



mq/l

1/1

100%

0.0018-0.0018

0.065

MDC

0.004



RSL

No SL

No

Yes

MDC > SL

Perfluorooctanoic acid (PFOA)



335-67-1

0.0047



0.0047



mq/l

1/1

100%

0.00037-0.00037

0.0047

MDC

0.006



RSL

No SL

No

No

MDC < SL

Total Metals

Aluminum



7429-90-5

100



100



mq/l

1/1

100%

4-4

100

MDC

2000



RSL

No SL

No

No

MDC < SL

Antimony



7440-36-0

N/A



N/A



mq/l

0/1

0%

0.32-0.32

0.32

MDL

0.78



RSL

No SL

No

No

MDL< SL

Arsenic



7440-38-2

N/A



N/A



mq/l

0/1

0%

0.33-0.33

0.33

MDL

0.052



RSL

No SL

No

See DSA

MDL > SL

Barium



7440-39-3

130



130



mq/l

1/1

100%

1.9-1.9

130

MDC

380



RSL

No SL

No

No

MDC < SL

Beryllium



7440-41-7

0.33

J

0.33

J

mq/l

1/1

100%

0.17-0.17

0.33

MDC

2.5



RSL

No SL

No

No

MDC < SL

Cadmium



7440-43-9

N/A



N/A



mq/l

0/1

0%

0.14-0.14

0.14

MDL

0.18



RSL

No SL

No

No

MDL< SL

Calcium



7440-70-2

12000



12000



mq/l

1/1

100%

120-120

12000

MDC

Nutrient



N/A

Nutrient

No

No

Classified as an essential nutrient

Chromium, Total



7440-47-3

0.5

J

0.5

J

mq/l

1/1

100%

0.32-0.32

0.5

MDC

2200

*

RSL

No SL

No

No

MDC < SL

Chromium, Hexavalent



18540-29-9

N/A



N/A



mq/l

0/1

0%

1-1

1

MDL

0.035



RSL

No SL

No

See DSA

MDL > SL

Cobalt



7440-48-4

4.4



4.4



mq/l

1/1

100%

0.19-0.19

4.4

MDC

0.6



RSL

No SL

No

Yes

MDC > SL

Copper



7440-50-8

7.7



7.7



mq/l

1/1

100%

0.4-0.4

7.7

MDC

80



RSL

No SL

No

No

MDC < SL

Iron



7439-89-6

290



290



mq/l

1/1

100%

54-54

290

MDC

1400



RSL

No SL

No

No

MDC < SL

Lead



7439-92-1

0.55

J

0.55

J

mq/l

1/1

100%

0.21 -0.21

0.55

MDC

15



RSL

No SL

No

No

MDC < SL

Manganese



7439-96-5

56

J+

56

J+

mq/l

1/1

100%

0.17-0.17

56

MDC

43



RSL

No SL

No

Yes

MDC > SL

Mercury



7439-97-6

N/A



N/A



mq/l

0/1

0%

0.06-0.06

0.06

MDL

0.2

*

RSL

No SL

No

No

MDL< SL

Nickel



7440-02-0

3.2



3.2



mq/l

1/1

100%

0.2-0.2

3.2

MDC

39



RSL

No SL

No

No

MDC < SL

Selenium



7782-49-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

10



RSL

No SL

No

No

MDL< SL

Silver



7440-22-4

N/A



N/A



mq/l

0/1

0%

0.18-0.18

0.18

MDL

9.4



RSL

No SL

No

No

MDL< SL

Thallium



7440-28-0

N/A



N/A



mq/l

0/1

0%

0.23-0.23

0.23

MDL

0.02



RSL

No SL

No

See DSA

MDL > SL

Vanadium



7440-62-2

N/A



N/A



mq/l

0/1

0%

1.2-1.2

1.2

MDL

8.6



RSL

No SL

No

No

MDL< SL

Zinc



7440-66-6

22



22



mq/l

1/1

100%

1.6-1.6

22

MDC

600



RSL

No SL

No

No

MDC < SL

Total Cyanide

Cyanide V 57-12-5 N/A N/A |jg/L 0/1 0% 2.6-2.6 2.6 MDL 0.15 RSL 20.1 No See DSA MDL > SL

Notes:

% = Percent
AL = Action Level

-------
Table A2-13

Occurrence, Distribution, and Selection of Constituents of Interest (Direct Contact - OU2; Groundwater, Well 0527)

Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current and Future

Medium: Groundwater (Drinking Water)
Well: 0527

Chemical|1!

CASRN

Minimum Detected
Concentration

Maximum
Detected
Concentration

Units

Detection
Frequency

Range of Method
Detection Limits

Screening
Concentration

Screening
Level (2'3'5'6)

Source

VISL'4'

Exceed
VISL?

COPC
Flag
(Yes/No)

Rationale for
Selection/Deletion

CASRN = Chemical Abstracts Service Registry Number
COPC = Chemical of Potential Concern
DSA = Data Sensitivity Analysis
HAL = Health Advisory Level
J = Indicates an estimated value

J+ = The result is an estimated quantity, but the result may be biased high.

MCL = Maximum Contaminant Level

MDC = Maximum Detected Concentration

N/A = Not Applicable

ND = Non-Detect or Not Detected

"PFOA and PFOS Combined" = Combined total of the detected concentrations of PFOA and PFOS (non-detect results were not included in the summation).

RL = Reporting Limit

RSL = Regional Screening Level

|jg/L = micrograms per liter

USEPA = United States Environmental Protection Agency

(1)	"V" indicates that the chemical is volatile.

(2)	Groundwater data screened against USEPA Tap Water RSLs, last updated May 2022 (TR = 1E-6, THQ = 0.1).

(3)	An asterisk,"*", indicates surrogate toxicity information was used to derive a Screening Level (see Table A2-14).

(4)	Groundwater data screened against USEPA Residential Groundwater VI SLs, last updated May 2022 (TR= 1E-6, THQ = 0.1). Site-specific, system temperature was set to 20.5 Celsius (average of recorded temperatures taken infield).

(6) Lead is compared to the EPA tap water RSL of 15 |jg/L, which represents the 90th percentile concentration of lead found in tap water samples collected nationwide (Lead and Copper Rule, 56 Federal Register 26460-26564, dated June 7,1991) and
is not a risk-based number, but rather an action level.

-------
Table A2-14

Surrogate Toxicity Used within Human Health Risk Assessment
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Chemical

CASRN

Surrogate

CASRN

1,1-Dichloropropene

563-58-6

1,3-Dichloropropene

542-75-6

1,3-Dichlorobenzene

541-73-1

1,2-Dichlorobenzene

95-50-1

1-Chlorohexane

544-10-5

Chlorobenzene

108-90-7

2,2-Dichloropropane

594-20-7

1,2-Dichloropropane

78-87-5

4-lsopropyltoluene

99-87-6

Cumene

98-82-8

cis-1,3-Dichloropropene

10061-01-5

1,3-Dichloropropene

542-75-6

m,p-Xylene

179601-23-1

m-Xylene

108-38-3

Methylcyclohexane

108-87-2

Cyclohexane

110-82-7

trans-1,3-Dichloropropene

10061-02-6

1,3-Dichloropropene

542-75-6

2-Nitrophenol

88-75-5

2-Amino-4,6-dinitrophenol

96-91-3

3&4-Methylphenol

108-39-4/106-44

3-Methylphenol

108-39-4

3-Nitroaniline

99-09-2

2-Nitroaniline

88-74-4

4-Bromophenyl phenyl ether

101-55-3

Pentabromodiphenyl ether

32534-81-9

4-Chlorophenyl phenyl ether

7005-72-3

Pentabromodiphenyl ether

32534-81-9

4-Nitrophenol

100-02-7

2-Amino-4,6-dinitrophenol

96-91-3

Acenaphthylene

208-96-8

Acenaphthene

83-32-9

Benzo(g,h,i)perylene

191-24-2

Pyrene

129-00-0

Carbazole

86-74-8

Fluorene

86-73-7

Dimethyl phthalate

131-11-3

Diethyl phthalate

84-66-2

Phenanthrene

85-01-8

Anthracene

120-12-7

Total PCDD/F TEQ (Mammal)

TEQ-M-DF

2,3,7,8-Tetrachlorodibenzo-p-dioxin

1746-01-6

Total PCB TEQ (Mammal)

TEQ-M-PCB

2,3,7,8-Tetrachlorodibenzo-p-dioxin

1746-01-6

Total PCB Congener

TPCB_CON

Polychlorinated Biphenyls (low risk)

1336-36-3L

Chromium, Total

7440-47-3

Chromium, Trivalent

16065-83-1

Mercury

7439-97-6

Methyl Mercury

22967-92-6

Notes:

PCB = Polychlorinated Biphenyls

PCDD = Polychlorinated Dibenzodioxins

CASRN = Chemical Abstracts Service Registry Number

TEQ = Toxicity Equivalence Factor

-------
-------
Table A3-1

Exposure Point Concentration Summary (Groundwater)
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

COPC

Units

Detection

Minimum

Maximum

Exposure Point Concentrationll!

Frequency

Concentration

Concentration

Value

Units

Statistic

Groundwater - Direct Contact (DC)

Well 0124

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.000011

0.000011

0.000011

mg/L

Max

Barium

mg/L

1/1

0.48

0.48

0.48

mg/L

Max

Cobalt

mg/L

1/1

0.03

0.03

0.03

mg/L

Max

Copper

mg/L

1/1

0.25

0.25

0.25

mg/L

Max

Manganese

mg/L

1/1

0.19

0.19

0.19

mg/L

Max

Cyanide

mg/L

1/1

0.0046

0.0046

0.0046

mg/L

Max

Well 0155

Arsenic

mg/L

1/1

0.00038

0.00038

0.00038

mg/L

Max

Barium

mg/L

1/1

1.1

1.1

1.1

mg/L

Max

Cadmium

mg/L

1/1

0.00033

0.00033

0.00033

mg/L

Max

Cobalt

mg/L

1/1

0.015

0.015

0.015

mg/L

Max

Copper

mg/L

1/1

0.14

0.14

0.14

mg/L

Max

Lead

mg/L

1/1

0.023

0.023

0.023

mg/L

Max

Manganese

mg/L

1/1

0.12

0.12

0.12

mg/L

Max

Cyanide

mg/L

1/1

0.0048

0.0048

0.0048

mg/L

Max

Well 0170

Chloroform

mg/L

1/1

0.0014

0.0014

0.0014

mg/L

Max

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.00026

0.00026

0.00026

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.000015

0.000015

0.000015

mg/L

Max

Chromium, Hexavalent

mg/L

1/1

0.00587

0.00587

0.00587

mg/L

Max

Cobalt

mg/L

1/1

0.0065

0.0065

0.0065

mg/L

Max

Nickel

mg/L

1/1

0.053

0.053

0.053

mg/L

Max

Well 0173

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.000024

0.000024

0.000024

mg/L

Max

Barium

mg/L

1/1

0.43

0.43

0.43

mg/L

Max

Cobalt

mg/L

1/1

0.022

0.022

0.022

mg/L

Max

Manganese

mg/L

1/1

0.22

0.22

0.22

mg/L

Max

Cyanide

mg/L

1/1

0.0095

0.0095

0.0095

mg/L

Max

Well 0176

Barium

mg/L

1/1

0.42

0.42

0.42

mg/L

Max

Cadmium

mg/L

1/1

0.0002

0.0002

0.0002

mg/L

Max

Cobalt

mg/L

1/1

0.014

0.014

0.014

mg/L

Max

Lead

mg/L

1/1

0.015

0.015

0.015

mg/L

Max

Manganese

mg/L

1/1

0.16

0.16

0.16

mg/L

Max

Cyanide

mg/L

1/1

0.009

0.009

0.009

mg/L

Max

Well 0182

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.00022

0.00022

0.00022

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.000013

0.000013

0.000013

mg/L

Max

Cobalt

mg/L

1/1

0.025

0.025

0.025

mg/L

Max

Manganese

mg/L

1/1

0.38

0.38

0.38

mg/L

Max

Cyanide

mg/L

1/1

0.0036

0.0036

0.0036

mg/L

Max

Well 0197

Chloroform

mg/L

1/1

0.00051

0.00051

0.00051

mg/L

Max

-------
Table A3-1

Exposure Point Concentration Summary (Groundwater)
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

COPC

Units

Detection
Frequency

Minimum
Concentration

Maximum
Concentration

Exposure Point Concentration(1)

Value

Units

Statistic

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.00015

0.00015

0.00015

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.000016

0.000016

0.000016

mg/L

Max

Cadmium

mg/L

1/1

0.00033

0.00033

0.00033

mg/L

Max

Cobalt

mg/L

1/1

0.013

0.013

0.013

mg/L

Max

Manganese

mg/L

1/1

0.18

0.18

0.18

mg/L

Max

Cyanide

mg/L

1/1

0.0032

0.0032

0.0032

mg/L

Max

Well 0212

Chloroform

mg/L

1/1

0.00028

0.00028

0.00028

mg/L

Max

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.000057

0.000057

0.000057

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.000011

0.000011

0.000011

mg/L

Max

Cobalt

mg/L

1/1

0.0016

0.0016

0.0016

mg/L

Max

Copper

mg/L

1/1

0.29

0.29

0.29

mg/L

Max

Lead

mg/L

1/1

0.016

0.016

0.016

mg/L

Max

Well 0275

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.00006

0.00006

0.00006

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.0000074

0.0000074

7.4E-06

mg/L

Max

Cadmium

mg/L

1/1

0.0002

0.0002

0.0002

mg/L

Max

Cobalt

mg/L

1/1

0.0018

0.0018

0.0018

mg/L

Max

Iron

mg/L

1/1

2.9

2.9

2.9

mg/L

Max

Manganese

mg/L

1/1

0.056

0.056

0.056

mg/L

Max

Well 0500

Barium

mg/L

1/1

0.69

0.69

0.69

mg/L

Max

Beryllium

mg/L

1/1

0.0036

0.0036

0.0036

mg/L

Max

Cadmium

mg/L

1/1

0.00044

0.00044

0.00044

mg/L

Max

Cobalt

mg/L

1/1

0.026

0.026

0.026

mg/L

Max

Manganese

mg/L

1/1

0.18

0.18

0.18

mg/L

Max

Well 0501

Chloroform

mg/L

1/1

0.00096

0.00096

0.00096

mg/L

Max

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.00013

0.00013

0.00013

mg/L

Max

Perfluorooctanoic acid (PFOA)

mg/L

1/1

0.000017

0.000017

0.000017

mg/L

Max

Cobalt

mg/L

1/1

0.016

0.016

0.016

mg/L

Max

Manganese

mg/L

1/1

0.26

0.26

0.26

mg/L

Max

Well 0510

Barium

mg/L

1/1

1.3

1.3

1.3

mg/L

Max

Cadmium

mg/L

1/1

0.00039

0.00039

0.00039

mg/L

Max

Cobalt

mg/L

1/1

0.02

0.02

0.02

mg/L

Max

Copper

mg/L

1/1

0.1

0.1

0.1

mg/L

Max

Manganese

mg/L

1/1

0.14

0.14

0.14

mg/L

Max

Cyanide

mg/L

1/1

0.011

0.011

0.011

mg/L

Max

Well 0527

Perfluorooctanesulfonic acid (PFOS)

mg/L

1/1

0.000065

0.000065

0.000065

mg/L

Max

Cobalt

mg/L

1/1

0.0044

0.0044

0.0044

mg/L

Max

Manganese

mg/L

1/1

0.056

0.056

0.056

mg/L

Max

Notes:

-------
Table A3-1

Exposure Point Concentration Summary (Groundwater)
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

COPC

Units

Detection

Minimum

Maximum

Exposure Point Concentration(1)

Frequency

Concentration

Concentration

Value Units Statistic

- = Not Evaluated	mg/L = milligram per liter

COPC = Chemical of Potential Concern

(1) Data set too small to calculate meaningful statistics. Therefore, maximum concentration was used for exposure point concentration.

-------
Table A3-2

Exposure Point Concentration Summary (Vapor Intrusion - Groundwater)
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

COPC

Units

Detection

Minimum

Maximum

Exposure Point Concentration '1,2]

Frequencyll!

Concentration

Concentration

Value Units Statistic

Groundwater - Vapor Intrusion (VI) - Well 0170

Chloroform

pg/L

1/1

1.4

1.4

0.176 |jg/m3 Max

Notes:

- = Not Evaluated	|jg/m3 = micrograms per cubic meter

COPC = Chemical of Potential Concern |jg/L = microgram per liter

(1)	Data set too small to calculate meaningful statistics. Therefore, maximum concentration was used for exposure point concentration.

(2)	The maximum concentration was used to estimate an indoor air concentration using the USEPA Vapor Intrusion Screening Level
(VISL) Calculator (see Table A3-3). A site-specific system temperature of 20.5 Celsius was used.

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware



Resident Air

Form-input

Variable

Default Value

Value

AFgw (Attenuation Factor Groundwater) unitless

0.001

0.001

AFSS (Attenuation Factor Sub-Slab) unitless

0.03

0.03

EDres (exposure duration) years

26

26

ED0_2 (mutagenic exposure duration tirst phase) years

2

2

ED2_6 (mutagenic exposure duration second phase) years

4

4

ED6_16 (mutagenic exposure duration third phase) years

10

10

ED-I6-26 (mutagenic exposure duration fourth phase) years

10

10

EFres (exposure frequency) days/year

350

350

EFq.2 (mutagenic exposure frequency tirst phase) days/year

350

350

EF2-6 (mutagenic exposure frequency second phase) days/year

350

350

EF6.16 (mutagenic exposure frequency third phase) days/year

350

350

EF16_26 (mutagenic exposure frequency fourth phase) days/year

350

350

ETres (exposure time) hours/day

24

24

ETq.2 (mutagenic exposure time tirst phase) hours/day

24

24

ET2-6 (mutagenic exposure time second phase) hours/day

24

24

ET6-i6 (mutagenic exposure time third phase) hours/day

24

24

ET16_26 (mutagenic exposure time fourth phase) hours/day

24

24

THQ (target hazard quotient) unitless

0.1

0.1

LT (lifetime) years

70

70

TR (target risk) unitless

0.000001

0.000001

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Resident Vapor
Intrusion
Screening
Levels (VISL)









Is Chemical

















Sufficiently

Is Chemical















Volatile and

Sufficiently





Target Sub-Slab







Does the

Toxic to Pose

Volatile and Toxic

Target Indoor



and Near-source





Does the

chemical

Inhalation Risk

to Pose Inhalation

Air



Soil Gas





chemical meet

have

Via Vapor

Risk Via Vapor

Concentration



Concentration





the definition

inhalation

Intrusion from

Intrusion from

(TCR=1E-06 or



(TCR=1E-06 or





for volatility?

toxicity data?

Soil Source?

Groundwater

THQ=0.1)



THQ=0.1)



CAS

(HLC>1E-5 or

(IUR and/or

(Cvp >

Source? (Che >

MIN(Cia,c,Cia,

Toxicity

Csg,Target

Chemical

Number

VP>1)

RfC)

Ci,a,Target?)

Ci,a,Target?)

nc) (|jg/m3)

Basis

(H9/m3)

Chloroform

67-66-3

Yes

Yes

Yes

Yes

1.22E-01

Cancer

4.07E+00

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Resident Vapor
Intrusion
Screening
Levels (VISL)



Target





















Groundwater







Temperature













Concentration

Is Target

Pure Phase

Maximum

for Maximum

Lower











(TCR=1E-06 or

Groundwater

Vapor

Groundwater

Groundwater

Explosive











THQ=0.1)

Concentration

Concentration

Vapor

Vapor

Limit LEL











Cgw,Target

< MCL? (Cgw

Cvp (25 °C)

Concentration

Concentration

(% by

LEL

IUR

IUR

RfC

Chemical

(M9/L)

< MCL?)

(|jg/m3)

Che (|jg/m3)

(°C)

volume)

Ref

(ug/m3)-1

Ref

(mg/m3)

Chloroform

9.72E-01

Yes (80)

1.26E+09

9.99E+08

2.05E+01

-



2.30E-05

IRIS

9.77E-02

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Resident Vapor
Intrusion
Screening
Levels (VISL)







Carcinogenic









VISL TCR=1E-

Noncarcinogenic



RfC

Mutagenic

06

VISL THQ=0.1

Chemical

Ref

Indicator

Cia,c(|jg/m3)

Cia,nc(|jg/m3)

Chloroform

ATSDR

No

1.22E-01

1.02E+01

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Resident
Vapor
Intrusion
Risk

Chemical

CAS Number

Site Groundwater
Concentration
Cgw (ng/L)

Site Indoor Air
Concentration Ci,a
(|jg/m3)

VI Carcinogenic
Risk CDI (|jg/m3)

VI Carcinogenic
Risk CR

VI Hazard

CDI
(mg/m3)

VI Hazard
HQ

IUR (ug/m3)-
1

IUR
Ref

Chloroform

67-66-3

1.40E+00

1.76E-01

6.26E-02

1.44E-06

1.69E-04

1.73E-03

2.30E-05

U

*Sum



-

-

-

1.44E-06

-

1.73E-03

-



-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Resident
Vapor
Intrusion
Risk

Chemical

Chronic

RfC
(mg/m3)

RfC
Ref

Temperature (°C) for
Groundwater Vapor
Concentration

Mutagen?

Chloroform

9.77E-02

U

2.05E+01

No

*Sum

-



-



-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Chemical
Properties





Does the chemical

Does the chemical













Henry's





meet the definition

have inhalation













Law



CAS

for volatility?

toxicity data? (IUR









MCL

HLC (atm-

Constant

Chemical

Number

(HLC>1E-5 or VP>1)

and/or RfC)

MW

MW Ref

S (mg/L)

S Ref

(ug/L)

m3/mole)

(unitless)

Chloroform

67-66-3

Yes

Yes

1.19E+02

PHYSPRO

7.95E+03

PHYSPRO

8.00E+01

3.67E-03

1.50E-01

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Chemical
Properties



Henry's





Enthalpy of

Enthalpy of











Law

Henry's Law



vaporization @

vaporization at the











Constant

Constant



groundwater

normal boiling



Normal



Exponent



(20.5 °C)

Used in Calcs

H and HLC

temperature AHv.gw

point AHv,b

AHv,b

Boiling Point



for

Chemical

(unitless)

(unitless)

Ref

(cal/mol)

(cal/mol)

Ref

BP (K)

BP Ref

AHV.gW

Chloroform

1.26E-01

1.26E-01

PHYSPROP

7.45E+03

6.99E+03

CRC

3.34E+02

PHYSPROP

3.45E-01

-------
Table A3-3

Residential VISL Model Input Values for Vapor Intrusion from Groundwater
Reasonable Maximum Exposure
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Chemical
Properties







Vapor











Vapor



Pressure





Lower





Pressure



VP

Critical



Explosive





VP

VP

(20.5 °C)

Temperatur

Tc

Limit LEL (%

LEL

Chemical

(mm Hg)

Ref

(mm Hg)

e Tc (K)

Ref

by volume)

Ref

Chloroform

1.97E+02

PHYSPROP

1.62E+02

5.36E+02

CRC

-



-------
Environmental 1 ransport and bate Models

-------
Environmental Transport and Fate Models

Environmental transport and fate models are needed when data for chemical concentrations in
certain exposure media and/or at certain exposure locations are not available. A transport and
fate model may be a simple cross-media transfer calculation (e.g., volatilization from
groundwater) or complex mathematical simulation. This appendix describes the methods and
models for evaluating:

1)	Permeability of inorganics and organics in water

a) Risk Assessment Guidance for Superfund (RAGS) Part D dermal worksheet for
groundwater (Table A4-3 [Reasonable Maximum Exposure (RME)])

2)	Volatilization of organics from groundwater

a) Modeled groundwater to vapor concentrations while showering (Table A4-4)

Modeling the environmental transport and fate of chemicals requires the use of simplified
assumptions to simulate the environment. In reality, migration, dispersion, uptake, and
degradation of chemicals in environmental media involve many complex processes that are not
always accurately represented in models. Although the use of models does introduce a source of
uncertainty into the overall risk calculations, despite their shortcomings, models are useful tools
for developing a general understanding of chemical movement in the environment, which allows
the quantitative evaluation of some exposure pathways that would otherwise be limited to a
qualitative or descriptive evaluation. The uncertainties associated with modeling environmental
transport and fate is discussed in the uncertainty analysis in the human health risk assessment
(HHRA) section.

Steady-State Concentrations from Dermal Absorption of Water

EPA's RACjS Part E, Supplement Guidance for Dermal Risk Assessment (EPA, 2004) provides a
mathematical model to estimate chemical absorption from water through the skin of the receptor.
Dermal absorption of the groundwater is addressed for the resident.

The skin is assumed to be composed of two main layers, the stratum corneum and the viable
epidermis, with the stratum corneum as the main barrier to absorption. A two-compartment
distributed model was developed to describe the absorption of chemicals from water through the
skin as a function of both the thickness of the stratum corneum and the event duration (EPA,
2004).

The mathematical representation of the mass balance equation follows Fick's second law (as
described in EPA's RAGS Part E guidance) and is a partial differential equation with
concentration as a function of both time and distance. The exact solution of this model is
approximated by two algebraic equations for organics:

•	DA-Event 1: describes the absorption process when the chemical is only in the stratum
corneum, i.e., non-steady state, where absorption is a function of t-event1/2

•	DA-Event 2: describes the absorption process as a function of lag time (Tau-event) once
steady state is reached. One fundamental assumption is that absorption continues long
after the exposure has ended, i.e., the final absorbed dose (DAeVent) is estimated to be the
total dose dissolved in the skin at the end of the exposure (EPA, 2004).

Appendix D, Attachment 4, Page 1

-------
The DA-event equation for inorganics is solely based on the function of t-event. The DA-event
equations for organics and inorganics are documented in Table A4-3 using RAGS Part D
Dermal Worksheet format for the RME groundwater.

For highly lipophilic chemicals or for chemicals that are not highly lipophilic but exhibit a long
lag time (Tau-event), some of the chemical dissolved into the skin may be lost due to
desquamation (skin peeling) during that absorption period. A fraction absorbed term (FA) is
included in the evaluation of DAeVent to account for this loss of chemical due to desquamation.
For normal desquamation rates to completely replace the stratum corneum in about 14 days, only
chemicals with log Kow> 3.5 or chemicals with t-event> 10 hours (at any log Kow) would be
affected by this loss (EPA, 2004).

Volatilization of Organics from Groundwater

Vapor Concentrations while Showering

Modeled vapors in the shower due to volatilization from groundwater were estimated using the
Foster-Chrostowski model (Foster, S.A. andP.C. Chrostowski, June 1987 and 2003). Although
volatiles may gain access to ambient air from most typical household uses of groundwater,
showering produces higher concentrations because the warm water temperature facilitates
volatilization, and the volatilized chemicals and the receptor are confined in a relatively small
space. Chemical-specific parameters for the model (e.g., molecular weight, Henry's Law
Constant) were taken from EPA sources such as EPA's Regional Screening Level table (EPA,
2022a).

Table A4-4 presents the Foster-Chrostowski step-by-step equations used to estimate shower
vapor concentrations.

Groundwater to Indoor Air (Vapor Intrusion')

Onsite groundwater was screened against EPA's groundwater vapor intrusion screening levels
(VISLs) using EPA's on-line calculator (EPA, 2022b). VISLs were calculated using a residential
scenario, a target risk of 1 x 10"6, a target hazard quotient of 0.1, and a site-specific average
groundwater temperature of 20.5 °C (68.9 °F). The site-specific temperature was generated by
averaging the temperatures recorded in the field during sampling.

Volatile groundwater chemicals that exceeded the residential VISLs were carried forward as
COPCs. VISL was used to estimate indoor air concentrations for the commercial/industrial
worker and hypothetical resident scenarios. The VISL model output is provided in Table A3-3.

Appendix D, Attachment 4, Page 2

-------
REFERENCES

EPA, 2004. Risk Assessment Guidance for Superfund Volume 1: Human Health Evaluation

Manual (PartE, Supplemental Guidance for Dermal Risk Assessment), Final. Office of
Superfund Remediation and Technology Innovation, EPA/540/R/99/005, OSWER
9285.7-02EP, July 2004.

EPA, 2011. Exposure Factors Handbook: 2011 Edition, National Center for Environmental
Assessment, Office of Research and Development. EPA/600/R-09/052F, September
2011.

EPA, 2022a. User's Guide and Regional Screening Levels Tables Dated May 2022.

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/usersguide.htm.

EPA, 2022b. Vapor Intrusion Screening Level (VISL) On-Line Calculator. May 2022.
http://www.epa.g0v/oswer/vaporintrusion/guidance.html#Item6

Foster, S.A. andP.C. Chrostowski, 1987. "Inhalation Exposures to Volatile Organic

Contaminants in the Shower." Presentation at the 80th Annual Meeting of the Air
Pollution Control Association.

Foster and Chrostowski, 2003. Integrated Human Exposure Model, Version 2 (IHEM2) for

Volatile Organic Compounds. Prepared for Syracuse Research Corporation/EPA under
EPA Grant No. CR-8310921-0. December 26, 2003.

Appendix D, Attachment 4, Page 3

-------
Table A4-1

Values Used for Daily Intake and Dermally Absorbed Dose Calculations
Reasonable Maximum Exposure: Incidental Ingestion and Dermal Absorption of Groundwater
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: CuirenUFuture
Medium:	Groundwater

Exposure Medium: Groundwater (Drinking Water)

Exposure Route

Receptor Population

Receptor
Age

Exposure Point

Parameter
Code

Parameter Definition

Value

Units

Rationale/ Reference

Intake and Dermally Absoibed Dose Equations/ Model Name



(Current/Future)



Ingestion of Groundwater
(Potable Use)











Non-Mutagenic Constituents

Daily Intake (mg/kg-day) for carcinogens (adult) =

CGW x IRGWa x EF x FI-GW x EDa



Daily Intake



mg/kg-day



CGW

Exposure Point Concentration, groundwater

Site-Specific

mg/L



IRGWa

Ingestion Rate, groundwater - adult

2.5

L/day

USEPA, 2014 (USEPA 2011; Table 3-33; 90th percentile of
consumer-only ingestion of drinking water (2 21 years))

BWa x ATc

Daily Intake (mg/kg-day) for noncarcinogens (adult) =

CGW x IRGWa x EF x FI-GW x EDa

FI-GW

Fraction Ingested from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100%) is assumed)

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

BWaxATnc,a

Daily Intake for carcinogens (lifetime) (mg/kg-day) =

[Dl for carcinogens (adult) + Dl for carcinogens (child)]

EDa

Exposure Duration, adult

20

years

USEPA, 2014 (EDr(26 years) - EDc (6 years))

BWa

Body Weight, adult

80

kg

USEPA, 2014 (USEPA, 2011; Tables 8-3; weighted mean
values adults 21-78)

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,a

Averaging Time, noncarcinogens - adult

7300

days

USEPA, 1989 (ED x 365 days/year)











Ingestion

On-Site Resident
(Current/Future)

Child

Ingestion of Groundwater
(Potable Use)











Non-Mutagenic Constituents

Daily Intake (mg/kg-day) for carcinogens (child) =

CGW x IRGWc x EF x FI-GW x EDc

Dl

Daily Intake

Calculated

mg/kg-day

See equations

CGW

Exposure Point Concentration, groundwater

Site-Specific

mg/L



IRGWc

Ingestion Rate, groundwater - child

0.78

L/day

USEPA, 2014 (USEPA 2011; Tables 3-15 and 3-33; weighted
average of 90th percentile consumer-only ingestion of drinking
water (birth < 6 years))

BWc x ATc

Daily Intake (mg/kg-day) for noncarcinogens (child) =

CGW x IRGWc x EF x FI-GW x EDc

FI-GW

Fraction Ingested from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100%) is assumed)

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

BWcxATnc,c
Daily Intake for carcinogens (lifetime) (mg/kg-day) =

[Dl for carcinogens (adult) + Dl for carcinogens (child)]

EDc

Exposure Duration, child

6

years

USEPA, 2014 (USEPA 1991; pp 6 and 15)

BWc

Body Weight, child

15

kg

USEPA, 2014 (USEPA 2011; Table 8-1; weighted average of
mean body weights (birth to < 6 years))

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,c

Averaging Time, noncarcinogens - child

2190

days

USEPA, 1989 (ED x 365 days/year)











Ingestion

On-Site Resident
(Current/Future)

Lifetime

Ingestion of Groundwater
(Potable Use)











Mutagenic Constituents

Daily Intake (mg/kg-day) for mutagenic carcinogens (lifetime) =

CGW x FI-GW xlFWMadi

Dl

Daily Intake

Calculated

mg/kg-day

See equations

CGW

Exposure Point Concentration, groundwater

Site-Specific

mg/L



FI-GW

Fraction Ingested from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100%) is assumed)

ATc

Where IFWMadj (L/kg) =

EFxlRGWc „ . -

BWC X[(ED0-2X™F0-2MED2.6XADAF2.6)]»

BW "[(ed6-16,adaf6-16Hed16-26,adaf16-26)]

IFWMadj

Mutagenic Water Ingestion Rate - Age-adjusted

1019.9

L/kg

See equations

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

IRGWc

Ingestion Rate, groundwater - child

0.78

L/day

USEPA, 2014 (USEPA 2011; Tables 3-15 and 3-33; weighted
average of 90th percentile consumer-only ingestion of drinking
water (birth < 6 years))

BWc

Body Weight, child

15

kg

USEPA, 2014 (USEPA 2011; Table 8-1; weighted average of
mean body weights (birth to < 6 years))

EDO-2

Exposure Duration, 0-2 years

2

years

USEPA, 2005

ADAFO-2

Age Depend. Adjust. Factor, 0-2 years

10

unitless

USEPA, 2005

ED2-6

Exposure Duration, 2-6 years

4

years

USEPA, 2005

ADAF2-6

Age Depend. Adjust. Factor, 2-6 years

3

unitless

USEPA, 2005

ED6-16

Exposure Duration, 6-16 years

10

years

USEPA, 2005

ADAF6-16

Age Depend. Adjust. Factor, 6-16 years

3

unitless

USEPA, 2005

ED16-26

Exposure Duration, 16-26 years

10

years

USEPA, 2005

ADAF16-26

Age Depend. Adjust. Factor, 16-26 years

1

unitless

USEPA, 2005

IRGWa

Ingestion Rate, groundwater - adult

2.5

L/day

USEPA, 2014 (USEPA 2011; Table 3-33; 90th percentile of
consumer-only ingestion of drinking water (2 21 years))

BWa

Body Weight, adult

80

kg

USEPA, 2014 (USEPA, 2011; Tables 8-3; weighted mean
values adults 21-78)

IFWadj

Water Ingestion Rate - Age-adjusted

327.95

L/kg

See equations











-------
Table A4-1

Values Used for Daily Intake and Dermally Absorbed Dose Calculations
Reasonable Maximum Exposure: Incidental Ingestion and Dermal Absorption of Groundwater
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: CuirenUFuture
Medium:	Groundwater

Exposure Medium: Groundwater (Drinking Water)

Exposure Route

Receptor Population

Receptor
Age

Exposure Point

Parameter
Code

Parameter Definition

Value

Units

Rationale/ Reference

Intake and Dermally Absoifoed Dose Equations/ Model Name

Dermal Absorption

(Current/Future)



Dermal Absorption of
Groundwater
(Potable Use)











Non-Mutagenic Constituents

Dermally Absorbed Dose (mgftg-day) for carcinogens (adult) =

DA-event x EV x EF x FC-GW x EDa x SA-GWa



Dermally Absorbed Dose



mgftg-day

,

DA-event

Absorbed Dose per Event

Calculated

mgfcm2-event

USE PA, 2004

EV

Event Frequency

1

events/day

USEPA, 2004

BWa x ATc

Dermally Absorbed Dose (mgftg-day) for noncarcinogens (adult) =

DA-event x EV x EF x FC-GW x EDa x SA-GWa

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

FC-GW

Fraction of Contact from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100°/c) is assumed)

EDa

Exposure Duration, adult

20

years

USEPA, 2014 (EDr(26 years) - EDc (6 years))

SA-GWa

Skin Surface Area - groundwater, adult

19652

cm2

USEPA, 2014 (USEPA 2011; Table 7-9; weighted average of
mean values for male and female adults, 21-78))

BWaxATnc,a

Where:

For organic compounds in which t-event,a £ t-star:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

2 x FA x Kp x CGW x CF1 x SQRT([6 x tau-event x t-event,a]/n)

For organic compounds in which t-event,a > t-star:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

FA x Kp x CGW x CF1 x {It-event,a / (1 + B)] + (2 x tau-event) x [(1 + 3B +3B2) / (1 + B)2]}

For inorganic compounds:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

KpxCGWx CF1 xt-event,a

Dermally Absorbed Dose (mgftg-day) for carcinogens (lifetime) =

[DAD for carcinogens (adult) + DAD for carcinogens (child)]

BWa

Body Weight, adult

80

kg

USEPA, 2014 (USEPA, 2011; Tables 8-3; weighted mean
values adults 21-78)

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,a

Averaging Time, noncarcinogens - adult

7300

days

USEPA, 1989 (ED x 365 days/year)

t-star

Time to reach steady-state

Chemical-specific

hour

USEPA, 2004; tau-event x 2.4

FA

Fraction Absorbed, water

Chemical-specific

unitless

USEPA,2004

Kp

Permeability Coefficient, water

Chemical-specific

cm/hour

USEPA, 2004

CGW

Exposure Point Concentration, groundwater

Site-Specific

mgfl.



CF1

Conversion Factor 1

0.001

L/cm3



tau-event

Lag time per event

Chemical-specific

hours/event

USEPA, 2004

t-event,a

Event Duration, adult

0.71

hours/event

USEPA, 2014 (USEPA 2011; Tables 16-30 and 16-31;
weighted average of adult (21 to 78) 90th percentile of time
spent bathingtehowering in a day, divided by mean number of
baths/showers taken in a day)

B

Ratio of Kp through stratum comeum relative to
compound's Kp across the viable epidermis

Chemical-specific

unitless

USEPA,2004











Dermal Absorption

On-Site Resident
(Current/Future)

Child

Dermal Absorption of
Groundwater
(Potable Use)











Non-Mutagenic Constituents

Dermally Absorbed Dose (mgftg-day) for carcinogens (child) =

DA-event x EV x EF x FC-GW x EDc x SA-GWc

DAD

Dermally Absorbed Dose

Calculated

mgftg-day

See equations

DA-event

Absorbed Dose per Event

Calculated

mgfcm2-event

USEPA, 2004

EV

Event Frequency

1

events/day

USEPA, 2004

BWc x ATc

Dermally Absorbed Dose (mgftg-day) for noncarcinogens (child) =

DA-event x EV x EF x FC-GW x EDc x SA-GWc

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

FC-GW

Fraction of Contact from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100%) is assumed)

EDc

Exposure Duration, child

6

years

USEPA, 2014 (USEPA 1991; pp 6 and 15)

SA-GWc

Skin Surface Area - groundwater, child

6365

cm2

USEPA, 2014 (USEPA 2011; Table 7-9; weighted average of
mean values for male and female children <6 years)

BWcxATnc,c

Where:

For organic compounds in which t-event,c £ t-star:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

2 x FA x Kp x CGW x CF1 x SQRT[(6 x tau-event x t-event,cyn]

For organic compounds in which t-event,c > t-star:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

FA x Kp x CGW x CF1 x {It-event,c / (1 + B)] + (2 x tau-event) x [(1 + 3B +3B2) / (1 + B)2]}

For inorganic compounds:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

Kp x CGW x CF1 x t-event,c

Dermally Absorbed Dose (mgftg-day) for carcinogens (lifetime) =

[DAD for carcinogens (adult) + DAD for carcinogens (child)]

BWc

Body Weight, child

15

kg

USEPA, 2014 (USEPA 2011; Table 8-1; weighted average of
mean body weights (birth to < 6 years))

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,c

Averaging Time, noncarcinogens - child

2190

days

USEPA, 1989 (ED x 365 days/year)

t-star

Time to reach steady-state

Chemical-specific

hour

USEPA, 2004; tau-event x 2.4

FA

Fraction Absorbed, water

Chemical-specific

unitless

USEPA,2004

Kp

Permeability Coefficient, water

Chemical-specific

cm/hour

USEPA, 2004

CGW

Exposure Point Concentration, groundwater

Site-Specific

mgfl.



CF1

Conversion Factor 1

0.001

L/cm3



tau-event

Lag time per event

Chemical-specific

hours/event

USEPA, 2004

t-event,c

Event Duration, child

0.54

hours/event

USEPA, 2014 (USEPA 2011; Table 16-28; weighted average
of 90th percentile time spent bathing (birth to < 6 years))

B

Ratio of Kp through stratum comeum relative to
compound's Kp across the viable epidermis

Chemical-specific

unitless

USEPA,2004











Dermal Absorption

On-Site Resident
(Current/Future)

Lifetime

Dermal Absorption of
Groundwater
(Potable Use)











Mutagenic Constituents

Dermally Absorbed Dose (mgftg-day) for mutagenic carcinogens (lifetime) =

DA-event x DFWMadj
ATc

Where:

For organic compounds in which ETewrt.res^d| £ t-star
DA-event (Absorbed Dose per Event[mgfcm2-event]) =

2 x FA x Kp x CGW x CF1 x SQRT([6 x tau-event x ETroert.res.ad|yn)

DAD

Dermally Absorbed Dose

Calculated

mgftg-day

See equations

DA-event

Absorbed Dose per Event

Calculated

mgfcm2-event

USEPA, 2004

DFWMadj



8191633

cm2-event/kg

See equations

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ETevert-res-ad,

Resident Water Exposure Time - Age Adjusted

0.6708

hours/event

USEPA, 2005

t-star

Time to reach steady-state

Chemical-specific

hour

USEPA, 2004; tau-event x 2.4

FA

Fraction Absorbed, water

Chemical-specific

unitless

USEPA,2004

Kp

Permeability Coefficient, water

Chemical-specific

cm/hour

USEPA, 2004

-------
Table A4-1

Values Used for Daily Intake and Dermally Absorbed Dose Calculations
Reasonable Maximum Exposure: Incidental Ingestion and Dermal Absorption of Groundwater
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: CuirenUFuture
Medium:	Groundwater

Exposure Medium: Groundwater (Drinking Water)

Exposure Route

Dermal Absorption

Receptor Population

On-Site Resident
(Current/Future)

Receptor
Age

Lifetime

Dermal Absorption of
Groundwater
(Potable Use)

Parameter
Code

Parameter Definition

Exposure Point Concentration, groundwater

Value

Site-Specific

Units

mgfl.

Rationale/ Reference

CGW

CF1









tau-event

Lag time per event

Chemical-specific

hours/event

USEPA,2004

B

Ratio of Kp through stratum comeum relative to
compound's Kp across the viable epidermis

Chemical-specific

unitless

USEPA, 2004

t-event,c

Event Duration, child

0.54

hours/event

USEPA, 2014 (USEPA 2011; Table 16-28; weighted average
of 90th percentile time spent bathing (birth to < 6 years))

EDO-2

Exposure Duration, 0-2 years

2

years

USEPA, 2005

ED2-6

Exposure Duration, 2-6 years

4

years

USEPA, 2005

ED6-16

Exposure Duration, 6-16 years

10

years

USEPA, 2005

ED16-26

Exposure Duration, 16-26 years

10

years

USEPA, 2005

ADAFO-2

Age Depend. Adjust. Factor, 0-2 years

10

unitless

USEPA, 2005

ADAF2-6

Age Depend. Adjust. Factor, 2-6 years

3

unitless

USEPA, 2005

ADAF6-16

Age Depend. Adjust. Factor, 6-16 years

3

unitless

USEPA, 2005

ADAF16-26

Age Depend. Adjust. Factor, 16-26 years

1

unitless

USEPA, 2005

t-event,a

Event Duration, adult

0.71

hours/event

USEPA, 2014 (USEPA 2011; Tables 16-30 and 16-31;
weighted average of adult (21 to 78) 90th percentile of time
spent bathingtehowering in a day, divided by mean number of
baths/showers taken in a day)

EV

Event Frequency

1

events/day

USEPA, 2004

EF

Exposure Frequency

350

days/year

USEPA, 2014 (USEPA 1991; pg 15)

SA-GWc

Skin Surface Area - groundwater, child

6365

cm2

USEPA, 2014 (USEPA 2011; Table 7-9; weighted average of
mean values for male and female children <6 years)

BWc

Body Weight, child

15

kg

USEPA, 2014 (USEPA 2011; Table 8-1; weighted average of
mean body weights (birth to < 6 years))

SA-GWa

Skin Surface Area - groundwater, adult

19652

cm2

USEPA, 2014 (USEPA 2011; Table 7-9; weighted average of
mean values for male and female adults, 21-78))

BWa

Body Weight, adult

80

kg

USEPA, 2014 (USEPA, 2011; Tables 8-3; weighted mean
values adults 21-78)

DFWadj

Dermal water contact factor- age-adjusted

2610650

cm2-event/kg

See equations

EDc

Exposure Duration, child

6

years

USEPA, 2014 (USEPA 1991; pp 6 and 15)

EDa

Exposure Duration, adult

20

years

USEPA, 2014 (EDr(26 years) - EDc (6 years))











Intake and Dermally Absoibed Dose Equations/ Model Name

For organic compounds in which ET > t-stai:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

FA x Kp x CGW x CF1 x flErewrt.re^d| / (1 + B)] + (2 x tau-event) x [(1 + 3B +3B2) / (1 + B f_

For inorganic compounds:

DA-event (Absorbed Dose per Event[mgfcm2-event]) =

Kp x CGW x CF1 x ETewrt.res^d|

Resident Water Exposure Time - Age Adjusted (hours/event) =

t-event,c x (EDq-2 -^D^g) +t-event,a x (EDg.16+ED1g.2g)
EDq-2 + ED2-6 + ED6_16 +ED16_26

Resident Water Dermal Contact Factor - Age Adjusted (cm2-event/kg) =

r,,rr. . fEDcx SA"GWC EDgX SA"GWa\
^ BWC + BWa )

Resident Mutagenic Water Dermal Contact Factor - Age Adjusted (cm2-event/kg) =
SA-GW,

EVxEFx

BWC
SA-GWg
. BWa

± x(ED0_2x ADAF0_2+ED2-6x ADAF2_6) -
CED6-16x ADAFg-^+ED^.^x ADAF16_26)

Notes:

- Not applicaple
References:

U.S. Environmental Protection Agency (USEPA), 1989. Risk Assessment Guidance for Superfund. Human Health Evaluation Manual. Part A Interim Final. 9285.701A.

U.S. Environmental Protection Agency (USEPA), 2004. Risk Assessment Guidance for Superfund Volume 1: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment), Final, July 2004.

U.S. Environmental Protection Agency (USEPA), 2005. Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens. Risk Assessment Forum, EPA Washington, DC. 20460, EPW63Q/R-03/003F. March.

U.S. Environmental Protection Agency (USEPA), 2011. Exposure Factors Handbook: 2011 Edition. EPW 600/R-090/052F, September 2011.

U.S. Environmental Protection Agency (USEPA), 2014. Human Health Evaluation Manual. Supplemental Guidance: Update of Standard Default Exposure Factors. Office of Superfund Remediation and Technology Innovation. OSWER Directive 9200.1-120. February 6. Amended September 2015.

-------
Table A4-2
Values Used for Daily Intake Calculations
Reasonable Maximum Exposure: Inhalation of Vapors from Groundwaters Indoor Air (Shower/Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Medium: Groundwater
Exposure Medium: Air	

Exposure Route

Receptor Population

Receptor
Aae

Exposure Point

Parameter
Code

Parameter Definition

Value

Units

Rationale/ Reference

Intake and Dermally Absorbed Dose Equations/ Model Name





t

Inhalation of Groundwater











Non-Mutagenic Constituents



(Current/Future)



Vapors in Indoor Air

EC

Exposure concentration

Calculated

|jg/m3

See equations

Exposure concentration (ngftn3) for carcinogens (lifetime) =







(Showering)

CA

Exposure Point Concentration, shower air

Modeled

|jg/m3

Calculated (See Attachment A4)

CA x ETs x EV x EF x FH-GW x EDa X CF2









ETs

Exposure Time, shower

0.33

hours/event

See equations

ATcx CF1 X CF2









EV

Event Frequency

l

event/day













Ds

Shower Duration

0.71

hour/event

USEPA,2014

Exposure concentration (jjg/m3) for non-carcinogens (lifetime) =









Ra

Air Exchange Rate

0.0167

1/hr

Foster and Chrostowski, 1987

CA x ETs x EV x EF x FH-GW x EDa X CF2

















USEPA, 2011; Table 16-29, 95th percentile value of 60 min (1

ATnc,a x CF1









ts,a

Total Time in Shower Room

1

hour

hour) for 16 to <21 years, total time spent in bathroom for
shower and remaining in enclosed bathroom.

Where:









EF

Exposure Frequency

350

days/year

USEPA, 2014(USEPA, 1991; pg 15)

Exposure Time, shower (hr/event) =









FH-GW

Fraction Inhaled from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100°/Q is assumed)

[ e(-Ra«ts,a) e(Ra«(Ds-ts,a))l









EDa

Exposure Duration, adult

20

years

USEPA, 2014 (EDr (26 years) - EDc (6 years))









ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

L Ra Ra J









ATnc,a

Averaging Time, noncarcinogens- adult

7300

days

USEPA, 1989 (ED x 365 days/year)

Note: It is assumed that the child resident does not take showers; however, early life exposure









CF1

Conversion Factor 1

24

hours/day



via bathing is taken into account with the mutagenic calculations.









CF2

Conversion Factor 2

1000

jjg/mg

























Inhalation

On-Site Resident

Lifetime

Inhalation of Groundwater











Mutagenic Constituents



(Current/Future)



Vapors in Indoor Air

EC

Exposure concentration

Calculated

|jg/m3

See equations

Exposure concentration (ngftn3) for mutagenic carcinogens (lifetime) =







(Bathing'Shower)

CA

Exposure Point Concentration, shower air

Modeled

|jg/m3

Calculated (See Attachment A4)











EF

Exposure Frequency

350

days/year

USEPA, 2014(USEPA, 1991; pg 15)

CAxEFxEVxETs-adj |Y EDq_2X ADAFq_2+ED2-0X ADAF2-0+ \1









ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATcxCF1 " |\ED6_16xADAF6_16+ED16_26XADAF16_26/]









CF1

Conversion Factor 1

24

hours/day













EDO-2

Exposure Duration, 0-2 years

2

years

USEPA, 2005

Where:









ADAFO-2

Age Depend. Adjust. Factor, 0-2 years

10

unitless

USEPA, 2005

Exposure Time, shower - age adjusted (hr/event) =









ED2-6

Exposure Duration, 2-6 years

4

years

USEPA, 2005

[ e(-Ra * ts-adj) e(Ra*(Ds ts adj))l









ADAF2-6

Age Depend. Adjust. Factor, 2-6 years

3

unitless

USEPA, 2005









ED6-16

Exposure Duration, 6-16years

10

years

USEPA, 2005

L Ra Ra J









ADAF6-16

Age Depend. Adjust. Factor, 6-16 years

3

unitless

USEPA, 2005











ED16-26

Exposure Duration, 16-26 years

10

years

USEPA, 2005

Total Time in Shower Room - age adjusted (hour) =









ADAF16-26

Age Depend. Adjust. Factor, 16-26 years

1

unitless

USEPA, 2005











EDr

Exposure Duration, lifetime

26

years

USEPA, 2014 (USEPA, 2011; Table 16-108; 90th percentile for
current residence time)

ts,c x (ED0_2 +ED2-e) +ts,a x (ED6_16+ED16_26)
EDq-2 + ED2-6 + ED6_16 +ED16_26









EV

Event Frequency

1

events/day

USEPA, 2004









CF2

Conversion Factor 2

0.0167

hr/min













ETs-adj

Exposure Time, shower - age adjusted

0.31

hours/event

See equations











Ds-adj

Shower Duration

0.625

hours/event

USEPA, 2014; average of child and adult resident water











exposure times of 0.54 hours/event and 0.71 hours/event











Ra

Air Exchange Rate

0.0167

1/hr

Foster and Chrostowski, 1987











ts-adj

Total Time in Shower Room - age adjusted

1

hour

See equations



















USEPA, 2011; Table 16-29, 95th percentile value of 60 min (1











ts,c

Total Time in Bathroom - child

1

hour

hour) for 3 to < 6 years old, total time spent taking a bath and
remaining in enclosed bathroom.



















USEPA, 2011; Table 16-29, 95th percentile value of 60 min (1











ts,a

Total Time in Bathroom - adult

1

hour

hour) for 16 to <21 years, total time spent in bathroom for
shower and remaining in enclosed bathroom.























Inhalation

On-Site Resident

Adult

Inhalation of Groundwater











Non-Mutagenic Constituents



(Current/Future)



Vapors in Indoor Air

EC

Exposure concentration

Calculated

jjg/m3

See equations

Exposure concentration (jjg/m3) for carcinogens (adult) =







(Vapor Intrusion)

CA

Exposure Point Concentration, indoor air

Modeled

jjg/m3

Calculated (See Attachment A4)

CA x ET xEFx FH-GW x EDa









ET

Exposure Time

24

hours/day

USEPA,2014

ATcx CF1









EF

Exposure Frequency

350

days/year

USEPA, 2014(USEPA, 1991; pg 15)











FH-GW

Fraction Inhaled from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100°/Q is assumed)

Exposure concentration (jjg/m3) for non-carcinogens (adult) =









EDa

Exposure Duration, adult

20

years

USEPA, 2014 (EDr (26 years) - EDc (6 years))

CA x ET xEFx FH-GW x EDa









ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,ax CF1

-------
Table A4-2
Values Used for Daily Intake Calculations
Reasonable Maximum Exposure: Inhalation of Vapors from Groundwaters Indoor Air (Shower/Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Medium: Groundwater
Exposure Medium: Air	

Exposure Route

Receptor Population

Receptor
Aae

Exposure Point

Parameter
Code

Parameter Definition

Value

Units

Rationale/ Reference

Intake and Dermally Absorbed Dose Equations/ Model Name



(Current/Future)

t

Inhalation of Groundwater
Vapors in Indoor Air
(Vapor Intrusion)

ATnc,a

Averaging Time, noncarcinogens- adult

7300

days

USEPA, 1989 (ED x 365 days/year)

Exposure concentration (ngftn3) for carcinogens (lifetime) =

[EC for carcinogens (adult) + EC for carcinogens (child)]

CF1

Conversion Factor 1

24

hours/day























Inhalation

On-Site Resident
(Current/Future)

Child

Inhalation of Groundwater
Vapors in Indoor Air
(Vapor Intrusion)











Non-Mutagenic Constituents

Exposure concentration (jjg/m3) for carcinogens (child) =

CA x ET xEFx FH-GW x EDc

EC

Exposure concentration

Calculated

|jg/m3

See equations

CA

Exposure Point Concentration, indoor air

Modeled

|jg/m3

Calculated (See Attachment A4)

ET

Exposure Time

24

hours/day

USEPA,2014

ATcx CF1

Exposure concentration (jjg/m3) for non-carcinogens (child) =

CA x ET xEFx FH-GW x EDc

EF

Exposure Frequency

350

days/year

USEPA, 2014(USEPA, 1991; pg 15)

FH-GW

Fraction Inhaled from Source, groundwater

1

unitless

USEPA, 1989 (Default of 1 (100°/Q is assumed)

EDc

Exposure Duration, child

6

years

USEPA, 2014(USEPA, 1991; pp6and 15)

ATc

Averaging Time, carcinogens

25550

days

USEPA, 1989 (ED (70 years) x 365 days/year)

ATnc,c x CF1

Exposure concentration (ngftn3) for carcinogens (lifetime) =

[EC for carcinogens (adult) + EC for carcinogens (child)]

ATnc,c

Averaging Time, noncarcinogens - child

2190

days

USEPA, 1989 (ED x 365 days/year)

CF1

Conversion Factor 1

24

hours/day























Inhalation

On-Site Resident
(Current/Future)

Lifetime

Inhalation of Groundwater
Vapors in Indoor Air
(Vapor Intrusion)











Mutagenic Constituents

Exposure concentration (ngftn3) for mutagenic carcinogens (lifetime) =

EC

Exposure concentration

Calculated

|jg/m3

See equations

CA

Exposure Point Concentration, indoor air

Modeled

|jg/m3

Calculated (See Attachment A4)

EF

Exposure Frequency

350

days/year

USEPA, 2014(USEPA, 1991; pg 15)

ET

Exposure Time

24

hours/day

USEPA,2014

ATcxCF1 " [yEDg_igX ADAFg_1g+ED1g_26>
-------
Table A4-3

Dermal Worksheet for Groundwater (Potable Use)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Groundwater Chemical of Potential
Concern

CASRN

Source: USEPA, 2004, RAGS Part E Dermal Guidance

On-Site Hypothetical Resident (Child) - Groundwater
(Potable Use)

On-Site Hypothetical Resident (Adult) - Groundwater
(Potable Use)

On-Site Hypothetical Resident (Lifetime) - Groundwater
(Potable Use)

t-event
(hrs/event):

0.54

Selected DA-event

t-event
(hrs/event):

0.71

Selected DA-event

t-event
(hrs/event):

0.67

Selected DA-event

FA
unitless

Kp
cm/hr

Tau-event
hrs/event

B

Value

T*
hr

DA-Event 1
(L/cm'-event)

DA-Event 2
(L/cm'-event)

Equation

DA-event
(L/cm'-event)

DA-Event 1
(L/cm'-event)

DA-Event 2
(L/cm'-event)

Equation

DA-event
(L/cm'-event)

DA-Event 1
(L/cm'-event)

DA-Event 2
(L/cm'-event)

Equation

DA-event
(L/cm'-event)

Volatile Organic Compounds (VOCs)

Chloroform

67-66-3

1

6.83E-03

4.90E-01

2.87E-02

1.18E+00

9.71E-06

1.05E-05

DA-Event 1

9.71 E-06

1.11E-05

1.16E-05

DA-Event 1

1.11E-05

1.08E-05

1.13E-05

DA-Event 1

1.08E-05

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

335-67-1

1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Perfluorooctanesulfonic acid (PFOS)

1763-23-1

1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Cyanide

Cyanide

57-12-5

1

1.00E-03

1.47E-01

1.96E-03

3.53E-01

7.79E-07

8.34E-07

DA-Event 2

8.34E-07

8.93E-07

1.00E-06

DA-Event 2

1.00E-06

8.68E-07

9.64E-07

DA-Event 2

9.64E-07

Metals (Total)

Arsenic

7440-38-2

1

1.00E-03

2.76E-01

3.33E-03

6.63E-01

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Barium

7440-39-3

1

1.00E-03

6.18E-01

4.51 E-03

1.48E+00

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Beryllium

7440-41-7

1

1.00E-03

1.18E-01

1.15E-03

2.83E-01

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Cadmium (Water)

7440-43-9W

1

1.00E-03

4.48E-01

4.08E-03

1.08E+00

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Chromium, Hexavalent

18540-29-9

1

2.00E-03

2.06E-01

5.55E-03

4.93E-01

1.08E-06

-

DA-Event 1

1.08E-06

1.42E-06

-

DA-Event 1

1.42E-06

1.34E-06

-

DA-Event 1

1.34E-06

Cobalt

7440-48-4

1

4.00E-04

2.25E-01

1.18E-03

5.40E-01

2.16E-07

-

DA-Event 1

2.16E-07

2.84E-07

-

DA-Event 1

2.84E-07

2.68E-07

-

DA-Event 1

2.68E-07

Copper

7440-50-8

1

1.00E-03

2.39E-01

3.07E-03

5.73E-01

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Iron

7439-89-6

1

1.00E-03

2.16E-01

2.87E-03

5.19E-01

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Manganese

7439-96-5

1

1.00E-03

2.14E-01

2.85E-03

5.13E-01

5.40E-07

-

DA-Event 1

5.40E-07

7.10E-07

-

DA-Event 1

7.10E-07

6.71 E-07

-

DA-Event 1

6.71 E-07

Nickel

7440-02-0

1

2.00E-04

2.24E-01

5.89E-04

5.38E-01

1.08E-07

-

DA-Event 1

1.08E-07

1.42E-07

-

DA-Event 1

1.42E-07

1.34E-07

-

DA-Event 1

1.34E-07

Parameters:

B = Dimensionless Ratio of the Permeability Coefficient of a Compound Through the

Stratum Corneum Relative to its Permeability Coefficient Across the Viable Epidermis
CF3 = Conversion Factor 3, 0.001 L/cm3
FA = Fraction Absorbed Water
Kp = Dermal Permeability Coefficient of

Compound in Water
T* = Time to Reach Steady-State
t-event = Event Duration (scenario-specific)

Tau-event = Lag Time per Event
DABS = Dermal Absorption Factor
References:

USEPA, 2004. Risk Assessment Guidance for Superfund, Volume 1, Human Health Evaluation Manual,
Part E, Supplemental Guidance for Dermal Risk Assessment, Final, July, EPA/540/R/99/005.

For Organic Compounds:

If t-event < T*, then: DA-event 1:

2 x FA x Kp x CF 3 x

6 X Tevent % tevent

If t-event > T* then: DA-event 2 =

tevent

FA x CF 3 x Kp x

1 + B

(2 X Tevent) ^

/I + 3 B + 3B2\

V (1 + fi)2 J

For Inorganic Compounds:

DA-event 1 = KP x CF3 x t-event
No DA-event 2 equation for inorganics.

-------
Table A4-4

Modeled Groundwater-to-Vapor Concentrations while Showering
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Groundwater Volatile COPC (Potable Use)

CASRN

MW
(g/mol)

H

(atm-m3/mol)

ki

(cm/hr)

kg
(cm/hr)

Kl
(cm/hr)

K„l
(cm/hr)

C,.,111
(ug/L)

C,d
(ug/L)

S

(uq/m3-min)

c„

(uq/m3)

Volatile Organic Compounds (VOCs)

Chloroform

67-66-3

1.19E+02

3.67E-03

1.21E+01

1.16E+03

1.14E+01

1.54E+01

1.00E+00

4.01E-01

1.34E+O0

8.01E-02

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

335-67-1





















Perfluorooctanesulfonic acid (PFOS)

1763-23-1





















Cyanide

Cyanide

57-12-5

2.60E+O1

1.01E-04

2.60E+O1

2.50E+O3

7.47E+O0

1.01E+01

1.00E+00

2.86E-01

9.53E-01

5.72E-02

Metals (Total)

Arsenic

7440-38-2





















Barium

7440-39-3





















Beryllium

7440-41-7





















Cadmium (Water)

7440-43-9W





















Chromium, Hexavalent

18540-29-9





















Cobalt

7440-48-4





















Copper

7440-50-8





















Iron

7439-89-6





















Manganese

7439-96-5





















Nickel

7440-02-0





















Notes:

(1) A value of 1 ug/L is used to calculate a shower concentration for all possible chemical of potential concerns (COPCs). The Site/COPC-specific groundwater exposure point concentration (EPC) will be multiplied by the generic air concentration value
to model shower air.

-- = Not Evaluated; only volatile chemicals evaluated; CASRN = Chemical Abstract Services Registry Number

Equations used for Foster-Chrostowski (1987) model

1) Derivation of Liauid-Film Mass Transfer Coefficient for the Shower Model

5) Derivation of Concentration Leaving Shower Droplet Shower Model

Values

calc
20
44

chem-specific

MW

20*(44/MW)Ub

Liquid-film mass transfer coefficient (cm/hour)

Liquid-film mass transfer coefficient for carbon dioxide (cm/hour)
Conversion factor (molecular weight of carbon dioxide)

Molecular Weight

2) Derivation of Gas-Film Mass Transfer Coefficient for the Shower Model

Values

calc
3000
18

chem-specific

kg= 3000* (18 /MW)ub

kg	Gas-film mass transfer coefficient (cm/hour)

Gas-film mass transfer coefficient for water (cm/hour)
Conversion factor (molecular weight of water)
MW	Molecular Weight

Values

calc
chem-specific
calc
2

60
1

Cwd = Cq * (1 - exp [ (-KaL * ts) / (60 * d) ])

C^j Concentration leaving shower droplet after time ts (|jg/L)
Cq Initial concentration in tap water (pg/L)
KaL Adjusted overall mass transfer coefficient (cm/hour)
ts	Shower droplet drop ti me (sec)

Interficial area for droplet multiplied by conversion factors
d	Shower droplet diameter (mm)

6) Derivation of VOC in Air Generation Rate Shower Model
S= (Cwd * FR) / SV

Values

calc	S	VOC in air generation rate (pg/m3-min)

calc	C^ Concentration leaving shower droplet after time ts(|jg/L)

-------
Table A4-5

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0155 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Lead Site-Specific Information for the Child Resident Scenario

Well ID

Medium

EPC Value

Units

0155

Groundwater

23

ljg/L

IEUBK Model Parameters



Value

Units

Indoor air lead concentration (% of outdoor)



30 [a]

%

AIR (by year)

Air Concentration







Age (years) =0-7



0.10 [a]

ug/m3

Time Outdoors







Age (months) = 6-12



1 [a]

hours

12-24



2 [a]

hours

24-36



3 [a]

hours

36-48



4 [a]

hours

48-60



4 [a]

hours

60-72



4 [a]

hours

72-84



4 [a]

hours

Ventilation Rate







Age (months) = 6-12



3.216 [a]

m3/day

12-24



4.970 [a]

m3/day

24-36



6.086 [a]

m3/day

36-48



6.954 [a]

m3/day

48-60



7.682 [a]

m3/day

60-72



8.318 [a]

m3/day

72-84



8.887 [a]

m3/day

Lung Absorption



32 [a]

%

-------
Table A4-5

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0155 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

DIET (by year)

Dietary Lead Intake







Age (months) = 6-12



2.26 [a]

|jg/day

12-24



5.03 [a]

|jg/day

24-36



5.21 [a]

|jg/day

36-48



5.38 [a]

|jg/day

48-60



5.64 [a]

|jg/day

60-72



6.04 [a]

|jg/day

72-84



5.95 [a]

|jg/day

ALTERNATE DIET SOURCES (by food class)

Used Alternate Diet Sources?



No

(Yes/No)

DRINKING WATER

Lead Concentration in drinking water



23

|jg Pb/L

Ingestion rate:







Age (months) = 6-12



0.40 [a]

L/day

12-24



0.43 [a]

L/day

24-36



0.51 [a]

L/day

36-48



0.54 [a]

L/day

48-60



0.57 [a]

L/day

60-72



0.60 [a]

L/day

72-84



0.63 [a]

L/day

-------
Table A4-5

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0155 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

SOIL/DUST INGESTION

Soil ingestion:











Age (months) =

6-12



200

[a]

|jg Pb/g



12-24



200

[a]

|jg Pb/g



24-36



200

[a]

|jg Pb/g



36-48



200

[a]

|jg Pb/g



48-60



200

[a]

|jg Pb/g



60-72



200

[a]

|jg Pb/g



72-84



200

[a]

|jg Pb/g

Household dust:











Age (months) =

6-12



150

[a]

|jg Pb/g



12-24



150

[a]

|jg Pb/g



24-36



150

[a]

|jg Pb/g



36-48



150

[a]

|jg Pb/g



48-60



150

[a]

|jg Pb/g



60-72



150

[a]

|jg Pb/g



72-84



150

[a]

|jg Pb/g

SOIL/DUST MULTIPLE SOURCE ANALYSIS

Average multiple source concentration



150.00 [a]

MQ/g

Mass fraction of outdoor soil to indoor dust conversion facto

0.70 [a]

unitless

Outdoor airborne lead to indoor household dust

1 nn Tai

jjg Pb/g dust

concentration







per |jg Pb/m3 air

ALTERNATE INDOOR DUST Pb SOURCES

Used Indoor Dust Pb Sources?



No



(Yes/No)

-------
Table A4-5

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0155 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS

Total lead absorption (at low intake): Total Soil

soil 30 [a]
dust 30 [a]
water 50 [a]
diet 50 [a]
alternate source 0 [a]

%
%
%
%
%

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS (continued)

Fraction of total net absorption at low intake rate that is
attributable to non-saturable (passive) processes

unitless

MATERNAL-TO-NEWBORN LEAD EXPOSURE

Mothers blood lead concentration at childbirth 0.6 [a]

|jg/dL

PLOTTING AND RISK ESTIMATION

Geometric standard deviation (GSD) for blood lead 1.6 [a]
Blood lead level (BLL) of concern 5 [a]

unitless
|jg/dL

COMPUTATION OPTIONS

Iteration time step for numerical integration 4 [a]

hours

PROBABILITY DISTRIBUTION PERCENT RESULTS

Geometric mean 4.1 Calc
Age Range 12-72 [a]
Percent above allowable BLL 34 Calc

unitless
months

%

Notes:

[1] Young child = 0-7 years of age (12-72 months) (EPA 2021b).
[a] IEUBK model default value (EPA 2021 a and 2021 b).



L/day = liters per day |jg/dL = micrograms per deciliter



-------
Table A4-5

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0155 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Pb = lead

jjg/m3 = micrograms per cubic meter
|jg/L = micrograms per liter

|jg/g = micrograms per gram
mg/kg = milligrams per kilogram

References:

EPA 2021a. Integrated Exposure Uptake Biokinetic Model for Lead in Children, Windows® version
(IEUBKwinv2 build 1.66) Dated May 2021.

EPA 2021b. User's Guide for the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK)
Windows® version 2 (Updated May 2021). The Technical Review Workgroup (TRW) Lead Committee.

-------
Prob. Density (Blood Pb]

Blood Pb Cone (|lg/dL)

Cutoff = 5.000 |lg/dl	Age Range = 12 to 72 months

Geo Mean = 4.100

GSD = 1.600	Run Mode = Research

% Above = 33.647	Comment = 0155- 23 ug/L

% Below = 66.353

These IEUBK Model results are valid as long as they were produced with an official, unmodified version of the IEUBK Model with a software certificate.

While IEUBK Model output is generally written with three digits to the right of the decimal point, the true precision of the output is strongly influenced by least precise input values.

-------
Table A4-6

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0176 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Lead Site-Specific Information for the Child Resident Scenario

Well ID

Medium

EPC Value

Units

0176

Groundwater

15

ljg/L

IEUBK Model Parameters



Value

Units

Indoor air lead concentration (% of outdoor)



30 [a]

%

AIR (by year)

Air Concentration







Age (years) =0-7



0.10 [a]

ug/m3

Time Outdoors







Age (months) = 6-12



1 [a]

hours

12-24



2 [a]

hours

24-36



3 [a]

hours

36-48



4 [a]

hours

48-60



4 [a]

hours

60-72



4 [a]

hours

72-84



4 [a]

hours

Ventilation Rate







Age (months) = 6-12



3.216 [a]

m3/day

12-24



4.97 [a]

m3/day

24-36



6.086 [a]

m3/day

36-48



6.954 [a]

m3/day

48-60



7.682 [a]

m3/day

60-72



8.318 [a]

m3/day

72-84



8.887 [a]

m3/day

Lung Absorption



32 [a]

%

-------
Table A4-6

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0176 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

DIET (by year)

Dietary Lead Intake







Age (months) = 6-12



2.26 [a]

|jg/day

12-24



5.03 [a]

|jg/day

24-36



5.21 [a]

|jg/day

36-48



5.38 [a]

|jg/day

48-60



5.64 [a]

|jg/day

60-72



6.04 [a]

|jg/day

72-84



5.95 [a]

|jg/day

ALTERNATE DIET SOURCES (by food class)

Used Alternate Diet Sources?



No

(Yes/No)

DRINKING WATER

Lead Concentration in drinking water



15

|jg Pb/L

Ingestion rate:







Age (months) = 6-12



0.40 [a]

L/day

12-24



0.43 [a]

L/day

24-36



0.51 [a]

L/day

36-48



0.54 [a]

L/day

48-60



0.57 [a]

L/day

60-72



0.60 [a]

L/day

72-84



0.63 [a]

L/day

-------
Table A4-6

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0176 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

SOIL/DUST INGESTION

Soil ingestion:











Age (months) =

6-12



200

[a]

|jg Pb/g



12-24



200

[a]

|jg Pb/g



24-36



200

[a]

|jg Pb/g



36-48



200

[a]

|jg Pb/g



48-60



200

[a]

|jg Pb/g



60-72



200

[a]

|jg Pb/g



72-84



200

[a]

|jg Pb/g

Household dust:











Age (months) =

6-12



150

[a]

|jg Pb/g



12-24



150

[a]

|jg Pb/g



24-36



150

[a]

|jg Pb/g



36-48



150

[a]

|jg Pb/g



48-60



150

[a]

|jg Pb/g



60-72



150

[a]

|jg Pb/g



72-84



150

[a]

|jg Pb/g

SOIL/DUST MULTIPLE SOURCE ANALYSIS

Average multiple source concentration



150.00 [a]

MQ/g

Mass fraction of outdoor soil to indoor dust conversion facto

0.70 [a]

unitless

Outdoor airborne lead to indoor household dust

1 nn Tai

jjg Pb/g dust

concentration







per |jg Pb/m3 air

ALTERNATE INDOOR DUST Pb SOURCES

Used Indoor Dust Pb Sources?



No



(Yes/No)

-------
Table A4-6

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0176 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS

Total lead absorption (at low intake): Total Soil

soil 30 [a]
dust 30 [a]
water 50 [a]
diet 50 [a]
alternate source 0 [a]

%
%
%
%
%

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS (continued)

Fraction of total net absorption at low intake rate that is
attributable to non-saturable (passive) processes

unitless

MATERNAL-TO-NEWBORN LEAD EXPOSURE

Mothers blood lead concentration at childbirth 0.6 [a]

|jg/dL

PLOTTING AND RISK ESTIMATION

Geometric standard deviation (GSD) for blood lead 1.6 [a]
Blood lead level (BLL) of concern 5 [a]

unitless
|jg/dL

COMPUTATION OPTIONS

Iteration time step for numerical integration 4 [a]

hours

PROBABILITY DISTRIBUTION PERCENT RESULTS

Geometric mean 3.466 Calc
Age Range 12-72 [a]
Percent above allowable BLL 22 Calc

unitless
months

%

Notes:

[1] Young child = 0-7 years of age (12-72 months) (EPA 2021b).
[a] IEUBK model default value (EPA 2021 a and 2021 b).



L/day = liters per day |jg/dL = micrograms per deciliter



-------
Table A4-6

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0176 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Pb = lead

jjg/m3 = micrograms per cubic meter
|jg/L = micrograms per liter

|jg/g = micrograms per gram
mg/kg = milligrams per kilogram

References:

EPA 2021a. Integrated Exposure Uptake Biokinetic Model for Lead in Children, Windows® version
(IEUBKwinv2 build 1.66) Dated May 2021.

EPA 2021b. User's Guide for the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK)
Windows® version 2 (Updated May 2021). The Technical Review Workgroup (TRW) Lead Committee.

-------
Prob. Density (Blood Pb]

Blood Pb Cone (|lg/dL]

Cutoff = 5.000 Jlg/dl	Age Range = 12 to 72 months

Geo Mean = 3.466

GSD = 1.600	Run Mode = Research

% Above = 21.707	Comment = 0176-15 ug/L

% Below = 78.213

These IEUBK Model results are valid as long as they were produced with an official, unmodified version of the IEUBK Model with a software certificate.

While IEUBK Model output is generally written with three digits to the right of the decimal point the true precision of the output is strongly influenced by least precise input values.

-------
Table A4-7

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0212 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Lead Site-Specific Information for the Child Resident Scenario

Well ID

Medium

EPC Value

Units

0212

Groundwater

16

|jg/L

IEUBK Model Parameter'



Value

Units









A'R (by year)

Air Concentration







Age (years) =0-7



0.10 [a]

ua/m3

Time Outdoors







Age (months) =6-12



1 [a]

hours

12-24



2 [a]

hours

24-36



3 [a]

hours

36-48



4 [a]

hours

48-60



4 [a]

hours

60-72



4 [a]

hours

72-84



4 [a]

hours

Ventilation Rate







Age (months) =6-12



3.216 [a]

m3/day

12-24



4.97 [a]

m3/day

24-36



6.086 [a]

m3/day

36-48



6.954 [a]

m3/day

48-60



7.682 [a]

m3/day

60-72



8.318 [a]

m3/day

72-84



8.887 [a]

m3/dav

Lung Absorption



32 [a]

%

-------
Table A4-7

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0212 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

DIET (by year)

/ Lead Intake





Age (months) =6-12

2.26 [a]

jjg/day

12-24

5.03 [a]

jjg/day

24-36

5.21 [a]

jjg/day

36-48

5.38 [a]

jjg/day

48-60

5.64 [a]

jjg/day

60-72

6.04 [a]

jjg/day

72-84

5.95 [a]

jjg/day

ALTERNATE DIET SOURCES (byfo

3d class)





No

(Yes/No)

DRINKING WATER

Lead Concentration in drinking water

16

jjg Pb/L

Ingestion rate:





Age (months) =6-12

0.40 [a]

L/day

12-24

0.43 [a]

L/day

24-36

0.51 [a]

L/day

36-48

0.54 [a]

L/day

48-60

0.57 [a]

L/day

60-72

0.60 [a]

L/day

72-84

0.63 [a]

L/day

-------
Table A4-7

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0212 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

SOIL/DUST INGESTION

gestion:





Age (months) =6-12

200 [a]

|jg Pb/g

12-24

200 [a]

|jg Pb/g

24-36

200 [a]

|jg Pb/g

36-48

200 [a]

|jg Pb/g

48-60

200 [a]

|jg Pb/g

60-72

200 [a]

|jg Pb/g

72-84

200 [a]

|jg Pb/g

Household dust:





Age (months) =6-12

150 [a]

|jg Pb/g

12-24

150 [a]

|jg Pb/g

24-36

150 [a]

|jg Pb/g

36-48

150 [a]

|jg Pb/g

48-60

150 [a]

|jg Pb/g

60-72

150 [a]

|jg Pb/g

72-84

150 [a]

|jg Pb/g

SOIL/DUST MULTIPLE SOURCE ANALYSIS

Average multiple source concentration

150.00 [a]

Mg/g

Mass fraction of outdoor soil to indoor dust conversion factor

0.70 [a]

unitless

Outdoor airborne lead to indoor household dust concentration

100 [a]

|jg Pb/g dust
per uq Pb/m3air

ALTERNATE INDOOR DUST Pb SC

)URCES



Used Indoor Dust Pb Sources?

No

(Yes/No)

-------
Table A4-7

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0212 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS

sad absorption (at low intake): Total Soil



soil 30 [a]

%

dust 30 [a]

%

water 50 [a]

%

diet 50 [a]

%

alternate source 0 [a]

%

BIOAVAILABILITY FOR GUT ABSORPTION PATHWAYS (continued)

Fraction of total net absorption at low intake rate that is . .
attributable to non-saturable (passive) processes



MATERNAL-TO-NEWBORN LEAD EXPOSURE

Mothers blood lead concentration at childbirth 0.6 [a]



PLOTTING AND RISK ESTIMATION

Geometric standard deviation (GSD) for blood lead 1.6 [a]



Blood lead level (BLL) of concern 5 [a]



COMPUTATION OPTIONS

Iteration time step for numerical integration 4 [a]



PROBABILITY DISTRIBUTION PERCENT RESULTS

Geometric mean 3.547 Calc

unities:

Age Range 12-72 [a]

months

Percent above allowable BLL 23 Calc

%

Notes:

[1 ] Young child = 0-7 years of age (12 - 72 months) (EPA 2021b).
[a] IEUBK model default value (EPA 2021a and 2021b).

L/day = liters per day

|jg/dl_ = micrograms per deciliter

-------
Table A4-7

Integrated Exposure Uptake Biokinetic (IEUBK) Model Results
Lead in Groundwater, Child Resident
Residential Well 0212 Tapwater Results
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Pb = lead

|jg/m3 = micrograms per cubic meter
jjg/L = micrograms per liter

References:

|jg/g = micrograms per gram
mg/kg = milligrams per kilogram

EPA 2021a. Integrated Exposure Uptake Biokinetic Model for Lead in Children, Windows® version
(IEUBKwinv2 build 1.66) Dated May 2021.

EPA 2021b. User's Guide for the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK)
Windows® version 2 (Updated May 2021). The Technical Review Workgroup (TRW) Lead Committee.

-------
Prob. Density (Blood Pb]

Blood Pb Cone [|ig/dL]

Cutoff = 5.000 |lg/dl	Age Range = 12 to 72 months

Geo Mean = 3.517

GSD = 1.600	Run Mode = Research

% Above = 23.246	Comment = 0212-16 ug/L

% Below = 76.754

These IEUBK Model results are valid as long as they were produced with an official, unmodified version of the IEUBK Model with a software certificate.

While IEUBK Model output is generally written with three digits to the right of the decimal point the true precision of the output is strongly influenced by least precise input values.

-------
5

Human Health Carcinogenic Risk and Non-Carcinogenic

Hazard Calculations

-------
Table A5-1
Non-Cancer Toxicity Data - Oral/Dermal
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Inteiest

Cluonic/
Subchionic

Oial RfD

Oial Absoiption
Effiencyfoi Deimal 'h

Absoibed RfD foi Deimal,?l

Piimaiy Taiget
Oigan/Systemls)

Combined Uncertainty/
Modifying Factois

RfD: Taiget Oigan(s)

Value

Units

Value

Units

Souice(s)

Date(s)'1'
(MM/DD/YYYY)

Volatile Organic Compounds (VOCs)

Chloroform

Chronic

0.01

mg/kg-day

1

0.01

mg/kg-day

HP

100

IRIS

3/18/2022

Chloroform

Subchronic

0.1

mg/kg-day

1

0.1

mg/kg-day

HP

100

ATSDR

2/1/2022

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Chronic

0.000003

mg/kg-day

1

3.00E-06

mg/kg-day

DV

300

ATSDR

6/9/2022

Perfluorooctanoic acid (PFOA)

Subchronic

0.000003

mg/kg-day

1

3.00E-06

mg/kg-day

DV

300

ATSDR

6/9/2022

Perfluorooctanesulfonic acid (PFOS)

Chronic

0.000002

mg/kg-day

1

2.00E-06

mg/kg-day

DV

30

ATSDR

6/8/2022

Perfluorooctanesulfonic acid (PFOS)

Subchronic

0.000002

mg/kg-day

1

2.00E-06

mg/kg-day

DV

30

ATSDR

6/8/2022

Cyanide

Cyanide

Chronic

0.0006

mg/kg-day

1

0.0006

mg/kg-day

RP

3000

IRIS

4/7/2022

Cyanide

Subchronic

0.02

mg/kg-day

1

0.02

mg/kg-day

OT; EN; NV

500

HEAST

7/31/1997

Metals (Total)

Arsenic

Chronic

0.0003

mg/kg-day

1

0.0003

mg/kg-day

DM; HM

3

IRIS

4/7/2022

Arsenic

Subchronic

0.005

mg/kg-day

1

0.005

mg/kg-day

DM

10

IRIS

4/7/2022

Barium

Chronic

0.2

mg/kg-day

0.07

0.014

mg/kg-day

NV

300

IRIS

4/7/2022

Barium

Subchronic

0.2

mg/kg-day

0.07

0.014

mg/kg-day

UR

10

ATSDR

2/1/2022

Beryllium

Chronic

0.002

mg/kg-day

0.007

0.000014

mg/kg-day

Gl

300

IRIS

4/7/2022

Beryllium

Subchronic

0.005

mg/kg-day

0.007

0.000035

mg/kg-day

-

100

HEAST

7/31/1997

Cadmium (Water)

Chronic

0.0001

mg/kg-day

0.05

0.000005

mg/kg-day

UR

3

ATSDR

2/1/2022

Cadmium (Water)

Subchronic

0.0005

mg/kg-day

0.05

0.000025

mg/kg-day

MS

100

ATSDR

2/1/2022

Chromium, Hexavalent

Chronic

0.003

mg/kg-day

0.025

0.000075

mg/kg-day

-

900

IRIS

4/7/2022

Chromium, Hexavalent

Subchronic

0.005

mg/kg-day

0.025

0.000125

mg/kg-day

HM

100

ATSDR

2/1/2022

Cobalt

Chronic

0.0003

mg/kg-day

1

0.0003

mg/kg-day

EN

3000

PPRTV

4/7/2022

Cobalt

Subchronic

0.003

mg/kg-day

1

0.003

mg/kg-day

EN

300

PPRTV

4/7/2022

Copper

Chronic

0.04

mg/kg-day

1

0.04

mg/kg-day

Gl

-

HEAST

7/31/1997

Copper

Subchronic

0.01

mg/kg-day

1

0.01

mg/kg-day

Gl

3

ATSDR

2/1/2022

Iron

Chronic

0.7

mg/kg-day

1

0.7

mg/kg-day

Gl

1.5

PPRTV

4/7/2022

Iron

Subchronic

0.7

mg/kg-day

1

0.7

mg/kg-day

Gl

1.5

PPRTV

4/7/2022

Manganese

Chronic

0.024

mg/kg-day

0.04

0.00096

mg/kg-day

NV

3

-

4/7/2022

Manganese

Subchronic

-

mg/kg-day

0.04

-

mg/kg-day

-

-

-

4/7/2022

Nickel

Chronic

0.02

mg/kg-day

0.04

0.0008

mg/kg-day

OT

300

IRIS

4/7/2022

Nickel

Subchronic

0.02

mg/kg-day

0.04

0.0008

mg/kg-day

OT

300

HEAST

7/31/1997

Notes:

- = No Value; mg/kg-day = milligrams per kilogram -day; RfD = Reference Dose

(1)	Source: U.S. Environmental Protection Agency (EPA) July 2004. Risk Assessment Guidance for Superfund. Volume 1: Human
Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Final. Office of Emergency and Remedial
Response. Washington D.C. EPA/540/R/99/005.

(2)	To derive the Absorbed RfD for Dermal, the oral RfD is multiplied by the oral absorption efficiency.

RfD: Target Organ Source Information:

ATSDR = Agency for Toxic Substance & Disease Registry (https://www.atsdr.cdc.gov)
HEAST = Health Effects Assessment Summary Table (https://www.epa-heast.ornl.gov/)
IRIS = Integrated Risk Information System (https://www.epa.gov/iris)

PPRTV = Provisional Peer-Reviewed Toxicity Values (https://www.hhpprtv.ornl.gov/)

-------
Table A5-1
Non-Cancer Toxicity Data - Oral/Dermal
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware



Cluonic/
Subchionic

Oial RfD

Oial Absoiption
Effiencyfoi Deimal 'h

Absoibed RfD foi Deimal,?l

Piimaiy Taiget
Oigan/Systemls)

Combined Uncertainty/
Modifying Factois

RfD: Taiget Oigan(s)

Constituent of Interest

Value

Units

Value

Units

Souice(s)

Date(s)'1'
(MM/DD/YYYY)

Taiget Oigan Codes:

DM = Dermal	HP = Hepatic	OT = Other

DV = Developmental	IM = Immune	RP = Reproductive

EN = Endocrine	MS = Musculoskeletal UR = Urinary

Gl = Gastrointestinal	NV = Nervous

-------
Table A5-2
Non-Cancer Toxicity Data - Inhalation
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Inteiest

Cluonic/
Subchionic

Inhalation RfC

Piimaiy Taiget
Oigan/Systemls)

Combined Uncertainty/
Modifying Factois

RfC: Taiget Oigan(s)

Value

Units

Souice(s)

Date(s)
(MM/DD/YYYY)

Volatile Organic Compounds (VOCs)

Chloroform

Chronic

0.097652352

mg/nf

HP

100

ATSDR

2/1/2022

Chloroform

Subchronic

0.244130879

mg/nf

HP

100

ATSDR

2/1/2022

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Chronic

-

-

-

-

-

6/9/2022

Perfluorooctanoic acid (PFOA)

Subchronic

-

-

-

-

-

6/9/2022

Perfluorooctanesulfonic acid (PFOS)

Chronic

-

-

-

-

-

6/8/2022

Perfluorooctanesulfonic acid (PFOS)

Subchronic

-

-

-

-

-

6/8/2022

Cyanide

Cyanide

Chronic

0.0008

mg/nf

EN

3000

-

4/7/2022

Cyanide

Subchronic

-

-

-

-

-

4/7/2022

Metals (Total)

Arsenic

Chronic

0.000015

mg/nf

-

-

Cal EPA

4/7/2022

Arsenic

Subchronic

-

mg/nf

-

-

-

4/7/2022

Barium

Chronic

0.0005

mg/nf

DV

1000

HEAST

7/31/1997

Barium

Subchronic

0.005

mg/nf

DV

100

HEAST

7/31/1997

Beryllium

Chronic

0.00002

mg/nf

IM; RS

10

IRIS

4/7/2022

Beryllium

Subchronic

-

mg/nf

-

-

-

4/7/2022

Cadmium (Water)

Chronic

0.00001

mg/nf

UR

3

ATSDR

2/1/2022

Cadmium (Water)

Subchronic

-

mg/nf

-

-

-

4/7/2022

Chromium, Hexavalent

Chronic

0.0001

mg/nf

RS

300

IRIS

4/7/2022

Chromium, Hexavalent

Subchronic

0.0003

mg/nf

RS

30

ATSDR

2/1/2022

Cobalt

Chronic

0.000006

mg/nf

RS

300

PPRTV

4/7/2022

Cobalt

Subchronic

0.00002

mg/nf

RS

100

PPRTV

4/7/2022

Copper

Chronic

-

-

-

-

-

4/7/2022

Copper

Subchronic

-

-

-

-

-

4/7/2022

Iron

Chronic

-

-

-

-

-

4/7/2022

Iron

Subchronic

-

-

-

-

-

4/7/2022

Manganese

Chronic

0.00005

mg/nf

NV

1000

IRIS

4/7/2022

Manganese

Subchronic

-

mg/nf

-

-

-

4/7/2022

Nickel

Chronic

0.00009

mg/nf

RS

30

ATSDR

2/1/2022

Nickel

Subchronic

0.0002

mg/nf

RS

30

ATSDR

2/1/2022

Notes:

--= No Value

N/A = Not Available

RfC = Reference Concentration

Mg/nf = micrograms per cubic meter

(1) With the exception of HEAST, source date represents when toxicity data were researched in on-line databases.

Target Organ Source Information:

ATSDR = Agency for Toxic Substance & Disease Registry (https://www.atsdr.cdc.gov)
Cal EPA = California Environmental Protection Agency (https://calepa.ca.gov/)

HEAST = Health Effects Assessment Summary Table (https://www.epa-heast.ornl.gov/)
IRIS = Integrated Risk Information System (https://www.epa.gov/iris)

PPRTV = Provisional Peer-Reviewed Toxicity Values (https://www.hhpprtv.ornl.gov/)

-------
Table A5-2
Non-Cancer Toxicity Data - Inhalation
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware



Cluonic/
Subchionic

Inhalation RfC

Piimaiy Taiget
Oigan/Systemls)

Combined Uncertainty/
Modifying Factois

RfC: Taiget Oigan(s)

Constituent of Inteiest

Value

Units

Souice(s)

Date(s)
(MM/DD/YYYY)

Target Organ Codes:

CV = Cardiovascular	IM = Immune	RS = Respiratory

DM = Dermal	NV = Nervous	UR = Urinary

DV = Developmental	OC = Ocular

HM = Hematological	OT = Other

HP = Hepatic	RP = Reproductive

-------
Table A6-1
Cancer Toxicity Data - Oral/Dermal
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Interest

Oral Cancer Slope Factor

Oral Absorption

Absorbed Cancer Slope
Factor for Dermal""

Weight of Evidence/ Cancer Guideline

Cancer Slope Factor

Value

Units

Effiency for Dermal 'h

Value

Units

Description

Source(s)

Date! si'"
(MM/DD/YYYYl

Volatile Organic Compounds (VOCs)

Chloroform

0.031

kg-day/mg

1

0.031

kg-day/mg

N/A

Cal EPA

3/18/2022

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

7.00E-02

kg-day/mg

1

0.07

kg-day/mg

N/A

DWSHA

6/9/2022

Perfluorooctanesulfonic acid (PFOS)

-

kg-day/mg

1

-

kg-day/mg

-

-

6/8/2022

Cyanide

Cyanide

-

-

1

-

-

-

-

4/7/2022

Metals (Total)

Arsenic

1.5

kg-day/mg

1

1.5

kg-day/mg

A

IRIS

4/7/2022

Barium

-

-

0.07

-

-

-

-

4/7/2022

Beryllium

-

-

0.007

-

-

-

-

4/7/2022

Cadmium (Water)

-

-

0.05

-

-

-

-

4/7/2022

Chromium, Hexavalent

0.5

kg-day/mg

0.025

20

kg-day/mg

N/A

Cal EPA

4/7/2022

Cobalt

-

-

1

-

-

-

-

4/7/2022

Copper

-

-

1

-

-

-

-

4/7/2022

Iron

-

-

1

-

-

-

-

4/7/2022

Manganese

-

-

0.04

-

-

-

-

4/7/2022

Nickel

-

-

0.04

-

-

-

-

4/7/2022

Notes:

- = No Value; (mg/kg-day)"1 = one over milligrams per kilogram-day

(1)	Source: U.S. Environmental Protection Agency (EPA) July 2004. Risk Assessment Guidance for Superfund. Volume 1:

Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Final. Office of Emergency and
Remedial Response. Washington D.C. EPA/540/R/99/005.

(2)	To derive the Absorbed Cancer Slope Factor for Dermal, the oral cancer slope factor is divided by the oral absorption
efficiency for dermal.

(3)	With the exception of HEAST, source date represents when toxicity data were researched in on-line databases.

Sources:

BaP x TEF = Carcinogenicity determined by adjusting benzo(a)pyrene (BaP) by a toxicity equivalence factor (TEF)

Cal EPA = California Environmental Protection Agency (https://calepa.ca.gov/)

DWSHA = Drinking Water Standards and Health Advisories (https://www.epa.gov/sdwa/epa-non-regulatory-health-based-drinking-water-levels)

HEAST = Health Effects Assessment Summary Table (https://www.epa-heast.ornl.gov/)

IRIS = Integrated Risk Information System (https://www.epa.gov/iris)

PPRTV = Provisional Peer Reviewed Toxicity Values for Superfund (https://hhpprtv.ornl.gov/)

USEPA, 1986 = Guidelines for Carcinogen Risk Assessment

USEPA, 1996 = Proposed Guidelines for Carcinogen Risk Assessment

Weight of Evidence:

A= Human Carcinogen (USEPA, 1986)

B1 = Probable Human Carcinogen - Based on Limited Evidence in Humans (USEPA, 1986)

B2 = Probable Human Carcinogen - Based on Sufficient Evidence in Animals (USEPA, 1986)

C = Possible Human Carcinogen (USEPA, 1986)

Carcinogenic to Humans (USEPA, 2005)

Known/Likely Human Carcinogen (USEPA, 1996)

LI = Likely to be Carcinogenic to Humans (PPRTV)

Likely to be Carcinogenic to Humans (USEPA, 2005)

N/A = Not Available

SU = Suggestive Evidence of Carcinogenicity in Humans (PPRTV)

Suggestive Evidence of Carcinogenic Potential (CP) (USEPA, 2005)

-------
Table A6-1
Cancer Toxicity Data - Oral/Dermal
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Interest

Oral Cancer Slope Factor

Oral Absorption

Absorbed Cancer Slope
Factor for Dermal""

Weight of Evidence/ Cancer Guideline

Cancer Slope Factor

Value

Units

Effiency for Dermal 'h

Value

Units

Description

Source(s)

Date! si'"
(MM/DD/YYYYl

USEPA, 1999 = Revised Draft Guidelines for Carcinogen Risk Assessment
USEPA, 2005 = Guidelines for Carcinogen Risk Assessment

-------
Table A6-2
Cancer Toxicity Data - Inhalation
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Interest

Inhalation Unit Risk

Weight of Evidence/ Cancer Guideline
Description

Inhalation Unit Risk

Value

Units

Source(s)

Date(s)'1'
(MM/DD/YYYY)

Volatile Organic Compounds (VOCs)

Chloroform

0.000023

m3/|jg

Likely to be Carcinogenic to Humans

IRIS

3/18/2022

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

-

-

-

-

6/9/2022

Perfluorooctanesulfonic acid (PFOS)

-

-

-

-

6/8/2022

Cyanide

Cyanide

-

-

-

-

4/7/2022

Metals (Total)

Arsenic

0.0043

m3/|jg

A

IRIS

4/7/2022

Barium

-

-

-

-

4/7/2022

Beryllium

0.0024

m3/|jg

Known/Likely Human Carcinogen

IRIS

4/7/2022

Cadmium (Water)

0.0018

m3/|jg

B1

IRIS

4/7/2022

Chromium, Hexavalent

0.084

m3/|jg

Known/Likely Human Carcinogen

Cal EPA

4/7/2022

Cobalt

0.009

m3/|jg

LI

PPRTV

4/7/2022

Copper

-

-

-

-

4/7/2022

Iron

-

-

-

-

4/7/2022

Manganese

-

-

-

-

4/7/2022

Nickel

0.00026

m3/|jg

N/A

Cal EPA

4/7/2022

Notes:

- = No Value

(|jg/m3)-1 = one over micrograms per cubic meter

(1) With the exception of HEAST, source date represents when toxicity data were researched in on-line
Sources:

BaP x TEF = Carcinogencity determined by adjusting benzo(a)pyrene (BaP) by
a toxicity equivalence factor (TEF)

Cal EPA = California Environmental Protection Agency (https://calepa.ca.gov/)

HEAST = Health Effects Assessment Summary Table (https://www.epa-heast.ornl.gov/)

IRIS = Integrated Risk Information System (https://www.epa.gov/iris)

PPRTV = Provisional Peer Reviewed Toxicity Values for Superfund (https://hhpprtv.ornl.gov/)

USEPA, 1986 = Guidelines for Carcinogen Risk Assessment

USEPA, 1996 = Proposed Guidelines for Carcinogen Risk Assessment

USEPA, 1999 = Revised Draft Guidelines for Carcinogen Risk Assessment

USEPA, 2005 = Guidelines for Carcinogen Risk Assessment

Weight of Evidence:

A= Human Carcinogen (USEPA, 1986)

B1 = Probable Human Carcinogen - Based on Limited Evidence in Humans (USEPA, 1986)

B2 = Probable Human Carcinogen - Based on Sufficient Evidence in Animals (USEPA, 1986)

C = Possible Human Carcinogen (USEPA, 1986)

Carcinogenic to Humans (USEPA, 2005)

Known/Likely Human Carcinogen (USEPA, 1996)

LI = Likely to be Carcinogenic to Humans (PPRTV)

Likely to be Carcinogenic to Humans (USEPA, 2005)

N/A= Not Available

Suggestive Evidence of Carcinogenic Potential (USEPA, 2005)

-------
Table A6-2
Cancer Toxicity Data - Inhalation
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Constituent of Interest

Inhalation Unit Risk

Weight of Evidence/ Cancer Guideline

Inhalation Unit Risk

Value

Units

Description

Source(s)

Date(s)'1'
(MM/DD/YYYY)

-------
Table A7-1

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanesulfonic acid (PFOS)

1.10E-05

mg/L

(2)









5.48E-07

mg/kg-day

2.00E-06

mg/kg-day

0.3









Cyanide

































Cyanide

4.60E-03

mg/L

(2)









2.29E-04

mg/kg-day

6.00E-04

mg/kg-day

0.4









Metals (Total)

































Barium

4.80E-01

mg/L

(2)









2.39E-02

mg/kg-day

2.00E-01

mg/kg-day

0.1









Cobalt

3.00E-02

mg/L

(2)









1.50E-03

mg/kg-day

3.00E-04

mg/kg-day

5









Copper

2.50E-01

mg/L

(2)









1.25E-02

mg/kg-day

4.00E-02

mg/kg-day

0.3









Manganese

1.90E-01

mg/L

(2)









9.47E-03

mg/kg-day

2.40E-02

mg/kg-day

0.4







Exp. Route Total







6







Dermal

Cyanide

































Cyanide

4.60E-03

mg/L

(2)









1.56E-06

mg/kg-day

6.00E-04

mg/kg-day

0.003









Metals (Total)

































Barium

4.80E-01

mg/L

(2)









1.05E-04

mg/kg-day

1.40E-02

mg/kg-day

0.008









Cobalt

3.00E-02

mg/L

(2)



-





2.64E-06

mg/kg-day

3.00E-04

mg/kg-day

0.009









Copper

2.50E-01

mg/L

(2)









5.49E-05

mg/kg-day

4.00E-02

mg/kg-day

0.001









Manganese

1.90E-01

mg/L

(2)









4.17E-05

mg/kg-day

9.60E-04

mg/kg-day

0.04







Exp. Route Total







0.06





Exp. Point Total







7



Exp. Medium Total







7

Medium Total







7

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

7

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-2

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanesulfonic acid (PFOS)

1.10E-05

mg/L

(2)









3.30E-07

mg/kg-day

2.00E-06

mg/kg-day

0.2









Cyanide

































Cyanide

4.60E-03

mg/L

(2)









1.38E-04

mg/kg-day

6.00E-04

mg/kg-day

0.2









Metals (Total)

































Barium

4.80E-01

mg/L

(2)









1.44E-02

mg/kg-day

2.00E-01

mg/kg-day

0.07









Cobalt

3.00E-02

mg/L

(2)









8.99E-04

mg/kg-day

3.00E-04

mg/kg-day

3









Copper

2.50E-01

mg/L

(2)









7.49E-03

mg/kg-day

4.00E-02

mg/kg-day

0.2









Manganese

1.90E-01

mg/L

(2)









5.69E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







4







Dermal

Cyanide

































Cyanide

4.60E-03

mg/L

(2)









1.09E-06

mg/kg-day

6.00E-04

mg/kg-day

0.002









Metals (Total)

































Barium

4.80E-01

mg/L

(2)









8.03E-05

mg/kg-day

1.40E-02

mg/kg-day

0.006









Cobalt

3.00E-02

mg/L

(2)









2.01E-06

mg/kg-day

3.00E-04

mg/kg-day

0.007









Copper

2.50E-01

mg/L

(2)



-





4.18E-05

mg/kg-day

4.00E-02

mg/kg-day

0.001









Manganese

1.90E-01

mg/L

(2)









3.18E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.05





Exp. Point Total







4



Exp. Medium Total







4



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

2.63E-04

Ijg'm3

(2)









3.46E-03

jjg/m3

8.00E-01

jjg/m3

0.004







Exp. Route Total







0.004





Exp. Point Total







0.004



Exp. Medium Total







0.004

Medium Total







4

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

4

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-3

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Copper

Manganese

1.10E-05

4.60E-03

4.80E-01
3.00E-02
2.50E-01
1.90E-01

mg/L

mg/L

mg/L
mg/L
mg/L
mg/L

1.41E-07

5.90E-05

6.16E-03
3.85E-04
3.21E-03
2.44E-03

mg/kg-day

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)

(2)
(2)
(2)
(2)















Exp. Route Total















Dermal

Cyanide

Cyanide
Metals (Total)

Barium
Cobalt
Copper
Manganese

4.60E-03

4.80E-01
3.00E-02
2.50E-01
1.90E-01

mg/L

mg/L
mg/L
mg/L
mg/L

4.53E-07

3.29E-05
8.22E-07
1.71E-05
1.30E-05

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)
(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total











Exp. Medium Total











Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

2.63E-04

Ijg'm3

9.89E-04

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-4

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

4.80E-03

mg/L

(2)









2.39E-04

mg/kg-day

6.00E-04

mg/kg-day

0.4









Metals (Total)

































Arsenic

3.80E-04

mg/L

(2)









1.89E-05

mg/kg-day

3.00E-04

mg/kg-day

0.06









Barium

1.10E+00

mg/L

(2)









5.48E-02

mg/kg-day

2.00E-01

mg/kg-day

0.3









Cadmium (Water)

3.30E-04

mg/L

(2)









1.65E-05

mg/kg-day

1.00E-04

mg/kg-day

0.2









Cobalt

1.50E-02

mg/L

(2)









7.48E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Copper

1.40E-01

mg/L

(2)









6.98E-03

mg/kg-day

4.00E-02

mg/kg-day

0.2









Manganese

1.20E-01

mg/L

(2)









5.98E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







4







Dermal

Cyanide

































Cyanide

4.80E-03

mg/L

(2)









1.63E-06

mg/kg-day

6.00E-04

mg/kg-day

0.003









Metals (Total)

































Arsenic

3.80E-04

mg/L

(2)









8.35E-08

mg/kg-day

3.00E-04

mg/kg-day

0.0003









Barium

1.10E+00

mg/L

(2)









2.42E-04

mg/kg-day

1.40E-02

mg/kg-day

0.02









Cadmium (Water)

3.30E-04

mg/L

(2)









7.25E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

1.50E-02

mg/L

(2)









1.32E-06

mg/kg-day

3.00E-04

mg/kg-day

0.004









Copper

1.40E-01

mg/L

(2)



-





3.08E-05

mg/kg-day

4.00E-02

mg/kg-day

0.0008









Manganese

1.20E-01

mg/L

(2)



-





2.64E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.07





Exp. Point Total







4



Exp. Medium Total







4

Medium Total







4

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

4

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-5

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

4.80E-03

mg/L

(2)









1.44E-04

mg/kg-day

6.00E-04

mg/kg-day

0.2









Metals (Total)

































Arsenic

3.80E-04

mg/L

(2)









1.14E-05

mg/kg-day

3.00E-04

mg/kg-day

0.04









Barium

1.10E+00

mg/L

(2)









3.30E-02

mg/kg-day

2.00E-01

mg/kg-day

0.2









Cadmium (Water)

3.30E-04

mg/L

(2)









9.89E-06

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

1.50E-02

mg/L

(2)









4.49E-04

mg/kg-day

3.00E-04

mg/kg-day

1









Copper

1.40E-01

mg/L

(2)









4.20E-03

mg/kg-day

4.00E-02

mg/kg-day

0.1









Manganese

1.20E-01

mg/L

(2)









3.60E-03

mg/kg-day

2.40E-02

mg/kg-day

0.1







Exp. Route Total







2







Dermal

Cyanide

































Cyanide

4.80E-03

mg/L

(2)









1.13E-06

mg/kg-day

6.00E-04

mg/kg-day

0.002









Metals (Total)

































Arsenic

3.80E-04

mg/L

(2)









6.36E-08

mg/kg-day

3.00E-04

mg/kg-day

0.0002









Barium

1.10E+00

mg/L

(2)









1.84E-04

mg/kg-day

1.40E-02

mg/kg-day

0.01









Cadmium (Water)

3.30E-04

mg/L

(2)









5.52E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

1.50E-02

mg/L

(2)









1.00E-06

mg/kg-day

3.00E-04

mg/kg-day

0.003









Copper

1.40E-01

mg/L

(2)



-





2.34E-05

mg/kg-day

4.00E-02

mg/kg-day

0.0006









Manganese

1.20E-01

mg/L

(2)



-





2.01E-05

mg/kg-day

9.60E-04

mg/kg-day

0.02







Exp. Route Total







0.05





Exp. Point Total







2



Exp. Medium Total







2



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

2.74E-04

jjg/m3

(2)



-





3.61E-03

jjg/m3

8.00E-01

jjg/m3

0.005







Exp. Route Total







0.005





Exp. Point Total







0.005



Exp. Medium Total







0.005

Medium Total







2

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

2

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-6

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide
Cyanide
Metals (Total)

4.80E-03

mg/L

6.16E-05

mg/kg-day







(2)

















Arsenic

3.80E-04

mg/L

4.88E-06

mg/kg-day

1.50E+00

1/(mg/kg-day)

7E-06

(2)

















Barium

1.10E+00

mg/L

1.41E-02

mg/kg-day







(2)

















Cadmium (Water)

3.30E-04

mg/L

4.24E-06

mg/kg-day







(2)

















Cobalt

1.50E-02

mg/L

1.93E-04

mg/kg-day







(2)

















Copper

1.40E-01

mg/L

1.80E-03

mg/kg-day

-





(2)

















Manganese

1.20E-01

mg/L

1.54E-03

mg/kg-day







(2)



-











Exp. Route Total



7E-06











Dermal

Cyanide
Cyanide
Metals (Total)

4.80E-03

mg/L

4.73E-07

mg/kg-day







(2)

















Arsenic

3.80E-04

mg/L

2.60E-08

mg/kg-day

1.50E+00

1/(mg/kg-day)

4E-08

(2)

















Barium

1.10E+00

mg/L

7.54E-05

mg/kg-day







(2)

















Cadmium (Water)

3.30E-04

mg/L

2.26E-08

mg/kg-day







(2)

















Cobalt

1.50E-02

mg/L

4.11E-07

mg/kg-day







(2)

















Copper

1.40E-01

mg/L

9.60E-06

mg/kg-day







(2)

















Manganese

1.20E-01

mg/L

8.22E-06

mg/kg-day







(2)















Exp. Route Total



4E-08









Exp. Point Total



7E-06







Exp. Medium Total



7E-06







Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

2.74E-04

Ijg'm3

1.03E-03

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total



7E-06





Notes:















Total of Receptor Risks Across All Media

7E-06

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-7

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

(2)









6.98E-05

mg/kg-day

1.00E-02

mg/kg-day

0.007









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.50E-05

mg/L

(2)









7.48E-07

mg/kg-day

3.00E-06

mg/kg-day

0.2









Perfluorooctanesulfonic acid (PFOS)

2.60E-04

mg/L

(2)









1.30E-05

mg/kg-day

2.00E-06

mg/kg-day

6









Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

(2)









2.93E-04

mg/kg-day

3.00E-03

mg/kg-day

0.1









Cobalt

6.50E-03

mg/L

(2)









3.24E-04

mg/kg-day

3.00E-04

mg/kg-day

1









Nickel

5.30E-02

mg/L

(2)









2.64E-03

mg/kg-day

2.00E-02

mg/kg-day

0.1







Exp. Route Total







8







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

(2)









5.53E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0006









Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

(2)









2.58E-06

mg/kg-day

7.50E-05

mg/kg-day

0.03









Cobalt

6.50E-03

mg/L

(2)









5.71E-07

mg/kg-day

3.00E-04

mg/kg-day

0.002









Nickel

5.30E-02

mg/L

(2)









2.33E-06

mg/kg-day

8.00E-04

mg/kg-day

0.003







Exp. Route Total







0.04





Exp. Point Total







8



Exp. Medium Total







8



Indoor Air

Indoor Air
(Vapor Intrusion)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

1.76E-01

jjg/m3

(2)









1.69E-01

jjg/m3

9.77E+01

jjg/m3

0.002







Exp. Route Total







0.002





Exp. Point Total







0.002



Exp. Medium Total







0.002

Medium Total







8

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

8

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-8

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

(2)









4.20E-05

mg/kg-day

1.00E-02

mg/kg-day

0.004









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.50E-05

mg/L

(2)









4.49E-07

mg/kg-day

3.00E-06

mg/kg-day

0.1









Perfluorooctanesulfonic acid (PFOS)

2.60E-04

mg/L

(2)









7.79E-06

mg/kg-day

2.00E-06

mg/kg-day

4









Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

(2)









1.76E-04

mg/kg-day

3.00E-03

mg/kg-day

0.06









Cobalt

6.50E-03

mg/L

(2)









1.95E-04

mg/kg-day

3.00E-04

mg/kg-day

0.6









Nickel

5.30E-02

mg/L

(2)









1.59E-03

mg/kg-day

2.00E-02

mg/kg-day

0.08







Exp. Route Total







5







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

(2)









3.67E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0004









Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

(2)









1.96E-06

mg/kg-day

7.50E-05

mg/kg-day

0.03









Cobalt

6.50E-03

mg/L

(2)









4.35E-07

mg/kg-day

3.00E-04

mg/kg-day

0.001









Nickel

5.30E-02

mg/L

(2)









1.77E-06

mg/kg-day

8.00E-04

mg/kg-day

0.002







Exp. Route Total







0.03





Exp. Point Total







5



Exp. Medium Total







5



Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

1.12E-04

jjg/m3

(2)









1.48E-03

jjg/m3

9.77E+01

jjg/m3

0.00002







Exp. Route Total







0.00002





Exp. Point Total







0.00002



Exp. Medium Total







0.00002





Indoor Air
(Vapor Intrusion)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

1.76E-01

jjg/m3

(2)









1.69E-01

jjg/m3

9.77E+01

jjg/m3

0.002







Exp. Route Total







0.002





Exp. Point Total







0.002



Exp. Medium Total







0.002

Medium Total







5

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

5

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-9

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

1.80E-05

mg/kg-day

3.10E-02

1/(mg/kg-day)

6E-07

(2)

















Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.50E-05

mg/L

1.93E-07

mg/kg-day

7.00E-02

1/(mg/kg-day)

1E-08

(2)

















Perfluorooctanesulfonic acid (PFOS)

2.60E-04

mg/L

3.34E-06

mg/kg-day







(2)

















Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

2.34E-04

mg/kg-day

5.00E-01

1/(mg/kg-day)

1E-04

(2)

















Cobalt

6.50E-03

mg/L

8.34E-05

mg/kg-day







(2)

















Nickel

5.30E-02

mg/L

6.80E-04

mg/kg-day







(2)















Exp. Route Total



1E-04











Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

1.40E-03

mg/L

1.55E-06

mg/kg-day

3.10E-02

1/(mg/kg-day)

5E-08

(2)

















Metals (Total)

































Chromium, Hexavalent

5.87E-03

mg/L

2.52E-06

mg/kg-day

2.00E+01

1/(mg/kg-day)

5E-05

(2)

















Cobalt

6.50E-03

mg/L

1.78E-07

mg/kg-day







(2)



-













Nickel

5.30E-02

mg/L

7.27E-07

mg/kg-day







(2)















Exp. Route Total



5E-05









Exp. Point Total



2E-04







Exp. Medium Total



2E-04







Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

1.12E-04

Ijg'm3

4.22E-04

Ijg'm3

2.30E-05

m3/jj g

1E-08

(2)















Exp. Route Total



1E-08









Exp. Point Total



1E-08







Exp. Medium Total



1E-08









Indoor Air
(Vapor Intrusion)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

1.76E-01

jjg/m3

6.27E-02

jjg/m3

2.30E-05

m3/jj g

1E-06

(2)















Exp. Route Total



1E-06









Exp. Point Total



1E-06







Exp. Medium Total



1E-06





Medium Total



2E-04





Notes:















Total of Receptor Risks Across All Media

2E-04

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-10

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanesulfonic acid (PFOS)

2.40E-05

mg/L

(2)









1.20E-06

mg/kg-day

2.00E-06

mg/kg-day

0.6









Cyanide

































Cyanide

9.50E-03

mg/L

(2)









4.74E-04

mg/kg-day

6.00E-04

mg/kg-day

0.8









Metals (Total)

































Barium

4.30E-01

mg/L

(2)









2.14E-02

mg/kg-day

2.00E-01

mg/kg-day

0.1









Cobalt

2.20E-02

mg/L

(2)









1.10E-03

mg/kg-day

3.00E-04

mg/kg-day

4









Manganese

2.20E-01

mg/L

(2)









1.10E-02

mg/kg-day

2.40E-02

mg/kg-day

0.5







Exp. Route Total







6







Dermal

Cyanide

































Cyanide

9.50E-03

mg/L

(2)









3.22E-06

mg/kg-day

6.00E-04

mg/kg-day

0.005









Metals (Total)

































Barium

4.30E-01

mg/L

(2)









9.45E-05

mg/kg-day

1.40E-02

mg/kg-day

0.007









Cobalt

2.20E-02

mg/L

(2)









1.93E-06

mg/kg-day

3.00E-04

mg/kg-day

0.006









Manganese

2.20E-01

mg/L

(2)



-





4.83E-05

mg/kg-day

9.60E-04

mg/kg-day

0.05







Exp. Route Total







0.07





Exp. Point Total







6



Exp. Medium Total







6

Medium Total







6

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

6

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-11

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanesulfonic acid (PFOS)

2.40E-05

mg/L

(2)









7.19E-07

mg/kg-day

2.00E-06

mg/kg-day

0.4









Cyanide

































Cyanide

9.50E-03

mg/L

(2)









2.85E-04

mg/kg-day

6.00E-04

mg/kg-day

0.5









Metals (Total)

































Barium

4.30E-01

mg/L

(2)









1.29E-02

mg/kg-day

2.00E-01

mg/kg-day

0.06









Cobalt

2.20E-02

mg/L

(2)









6.59E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Manganese

2.20E-01

mg/L

(2)









6.59E-03

mg/kg-day

2.40E-02

mg/kg-day

0.3







Exp. Route Total







3







Dermal

Cyanide

































Cyanide

9.50E-03

mg/L

(2)









2.25E-06

mg/kg-day

6.00E-04

mg/kg-day

0.004









Metals (Total)

































Barium

4.30E-01

mg/L

(2)









7.19E-05

mg/kg-day

1.40E-02

mg/kg-day

0.005









Cobalt

2.20E-02

mg/L

(2)









1.47E-06

mg/kg-day

3.00E-04

mg/kg-day

0.005









Manganese

2.20E-01

mg/L

(2)



-





3.68E-05

mg/kg-day

9.60E-04

mg/kg-day

0.04







Exp. Route Total







0.05





Exp. Point Total







3



Exp. Medium Total







3



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

5.43E-04

jjg/m3

(2)



-





7.15E-03

jjg/m3

8.00E-01

jjg/m3

0.009







Exp. Route Total







0.009





Exp. Point Total







0.009



Exp. Medium Total







0.009

Medium Total







3

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

3

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-12

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Manganese

2.40E-05

9.50E-03

4.30E-01
2.20E-02
2.20E-01

mg/L

mg/L

mg/L
mg/L
mg/L

3.08E-07

1.22E-04

5.52E-03
2.82E-04
2.82E-03

mg/kg-day

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)

(2)
(2)
(2)















Exp. Route Total















Dermal

Cyanide

Cyanide
Metals (Total)

Barium
Cobalt
Manganese

9.50E-03

4.30E-01
2.20E-02
2.20E-01

mg/L

mg/L
mg/L
mg/L

9.36E-07

2.95E-05
6.03E-07
1.51E-05

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day

-





(2)

(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total











Exp. Medium Total











Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

5.43E-04

Ijg'm3

2.04E-03

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-13

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

9.00E-03

mg/L

(2)









4.49E-04

mg/kg-day

6.00E-04

mg/kg-day

0.7









Metals (Total)

































Barium

4.20E-01

mg/L

(2)









2.09E-02

mg/kg-day

2.00E-01

mg/kg-day

0.1









Cadmium (Water)

2.00E-04

mg/L

(2)









9.97E-06

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

1.40E-02

mg/L

(2)









6.98E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Manganese

1.60E-01

mg/L

(2)









7.98E-03

mg/kg-day

2.40E-02

mg/kg-day

0.3







Exp. Route Total







4







Dermal

Cyanide

































Cyanide

9.00E-03

mg/L

(2)









3.05E-06

mg/kg-day

6.00E-04

mg/kg-day

0.005









Metals (Total)

































Barium

4.20E-01

mg/L

(2)









9.23E-05

mg/kg-day

1.40E-02

mg/kg-day

0.007









Cadmium (Water)

2.00E-04

mg/L

(2)









4.39E-08

mg/kg-day

5.00E-06

mg/kg-day

0.009









Cobalt

1.40E-02

mg/L

(2)



-





1.23E-06

mg/kg-day

3.00E-04

mg/kg-day

0.004









Manganese

1.60E-01

mg/L

(2)









3.52E-05

mg/kg-day

9.60E-04

mg/kg-day

0.04







Exp. Route Total







0.06





Exp. Point Total







4



Exp. Medium Total







4

Medium Total







4

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

4

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-14

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

9.00E-03

mg/L

(2)









2.70E-04

mg/kg-day

6.00E-04

mg/kg-day

0.4









Metals (Total)

































Barium

4.20E-01

mg/L

(2)









1.26E-02

mg/kg-day

2.00E-01

mg/kg-day

0.06









Cadmium (Water)

2.00E-04

mg/L

(2)









5.99E-06

mg/kg-day

1.00E-04

mg/kg-day

0.06









Cobalt

1.40E-02

mg/L

(2)









4.20E-04

mg/kg-day

3.00E-04

mg/kg-day

1









Manganese

1.60E-01

mg/L

(2)









4.79E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







2







Dermal

Cyanide

































Cyanide

9.00E-03

mg/L

(2)









2.13E-06

mg/kg-day

6.00E-04

mg/kg-day

0.004









Metals (Total)

































Barium

4.20E-01

mg/L

(2)









7.02E-05

mg/kg-day

1.40E-02

mg/kg-day

0.005









Cadmium (Water)

2.00E-04

mg/L

(2)









3.34E-08

mg/kg-day

5.00E-06

mg/kg-day

0.007









Cobalt

1.40E-02

mg/L

(2)









9.37E-07

mg/kg-day

3.00E-04

mg/kg-day

0.003









Manganese

1.60E-01

mg/L

(2)



-





2.68E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.05





Exp. Point Total







2



Exp. Medium Total







2



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

5.14E-04

jjg/m3

(2)



-





6.77E-03

jjg/m3

8.00E-01

jjg/m3

0.008







Exp. Route Total







0.008





Exp. Point Total







0.008



Exp. Medium Total







0.008

Medium Total







2

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

2

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-15

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide
Cyanide
Metals (Total)

Barium

Cadmium (Water)

Cobalt

Manganese

9.00E-03

4.20E-01
2.00E-04
1.40E-02
1.60E-01

mg/L

mg/L
mg/L
mg/L
mg/L

1.16E-04

5.39E-03
2.57E-06
1.80E-04
2.05E-03

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)
(2)
(2)
(2)















Exp. Route Total















Dermal

Cyanide
Cyanide
Metals (Total)

Barium

Cadmium (Water)

Cobalt

Manganese

9.00E-03

4.20E-01
2.00E-04
1.40E-02
1.60E-01

mg/L

mg/L
mg/L
mg/L
mg/L

8.87E-07

2.88E-05
1.37E-08
3.84E-07
1.10E-05

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day

-





(2)

(2)
(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total











Exp. Medium Total











Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

5.14E-04

Ijg'm3

1.94E-03

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-16

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.30E-05

mg/L

(2)









6.48E-07

mg/kg-day

3.00E-06

mg/kg-day

0.2









Perfluorooctanesulfonic acid (PFOS)

2.20E-04

mg/L

(2)









1.10E-05

mg/kg-day

2.00E-06

mg/kg-day

5









Cyanide

































Cyanide

3.60E-03

mg/L

(2)









1.80E-04

mg/kg-day

6.00E-04

mg/kg-day

0.3









Metals (Total)

































Cobalt

2.50E-02

mg/L

(2)









1.25E-03

mg/kg-day

3.00E-04

mg/kg-day

4









Manganese

3.80E-01

mg/L

(2)









1.89E-02

mg/kg-day

2.40E-02

mg/kg-day

0.8







Exp. Route Total







11







Dermal

Cyanide

































Cyanide

3.60E-03

mg/L

(2)









1.22E-06

mg/kg-day

6.00E-04

mg/kg-day

0.002









Metals (Total)

































Cobalt

2.50E-02

mg/L

(2)









2.20E-06

mg/kg-day

3.00E-04

mg/kg-day

0.007









Manganese

3.80E-01

mg/L

(2)









8.35E-05

mg/kg-day

9.60E-04

mg/kg-day

0.09







Exp. Route Total







0.1





Exp. Point Total







11



Exp. Medium Total







11

Medium Total







11

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

11

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-17

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.30E-05

mg/L

(2)









3.90E-07

mg/kg-day

3.00E-06

mg/kg-day

0.1









Perfluorooctanesulfonic acid (PFOS)

2.20E-04

mg/L

(2)









6.59E-06

mg/kg-day

2.00E-06

mg/kg-day

3









Cyanide

































Cyanide

3.60E-03

mg/L

(2)









1.08E-04

mg/kg-day

6.00E-04

mg/kg-day

0.2









Metals (Total)

































Cobalt

2.50E-02

mg/L

(2)









7.49E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Manganese

3.80E-01

mg/L

(2)









1.14E-02

mg/kg-day

2.40E-02

mg/kg-day

0.5







Exp. Route Total







7







Dermal

Cyanide

































Cyanide

3.60E-03

mg/L

(2)









8.51E-07

mg/kg-day

6.00E-04

mg/kg-day

0.001









Metals (Total)

































Cobalt

2.50E-02

mg/L

(2)









1.67E-06

mg/kg-day

3.00E-04

mg/kg-day

0.006









Manganese

3.80E-01

mg/L

(2)









6.36E-05

mg/kg-day

9.60E-04

mg/kg-day

0.07







Exp. Route Total







0.07





Exp. Point Total







7



Exp. Medium Total







7



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

2.06E-04

jjg/m3

(2)









2.71E-03

jjg/m3

8.00E-01

jjg/m3

0.003







Exp. Route Total







0.003





Exp. Point Total







0.003



Exp. Medium Total







0.003

Medium Total







7

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

7

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-18

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.30E-05

mg/L

1.67E-07

mg/kg-day

7.00E-02

1/(mg/kg-day)

1E-08

(2)

















Perfluorooctanesulfonic acid (PFOS)

2.20E-04

mg/L

2.82E-06

mg/kg-day







(2)

















Cyanide

































Cyanide

3.60E-03

mg/L

4.62E-05

mg/kg-day







(2)

















Metals (Total)

































Cobalt

2.50E-02

mg/L

3.21E-04

mg/kg-day







(2)

















Manganese

3.80E-01

mg/L

4.88E-03

mg/kg-day







(2)















Exp. Route Total



1E-08











Dermal

Cyanide

Cyanide
Metals (Total)

Cobalt
Manganese

3.60E-03

2.50E-02
3.80E-01

mg/L

mg/L
mg/L

3.55E-07

6.85E-07
2.60E-05

mg/kg-day

mg/kg-day
mg/kg-day

-





(2)

(2)
(2)















Exp. Route Total













Exp. Point Total



1E-08







Exp. Medium Total



1E-08







Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

2.06E-04

Ijg'm3

7.74E-04

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total



1E-08





Notes:















Total of Receptor Risks Across All Media

1E-08

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-19

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

(2)









2.54E-05

mg/kg-day

1.00E-02

mg/kg-day

0.003









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.60E-05

mg/L

(2)









7.98E-07

mg/kg-day

3.00E-06

mg/kg-day

0.3









Perfluorooctanesulfonic acid (PFOS)

1.50E-04

mg/L

(2)









7.48E-06

mg/kg-day

2.00E-06

mg/kg-day

4









Cyanide

































Cyanide

3.20E-03

mg/L

(2)









1.60E-04

mg/kg-day

6.00E-04

mg/kg-day

0.3









Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

(2)









1.65E-05

mg/kg-day

1.00E-04

mg/kg-day

0.2









Cobalt

1.30E-02

mg/L

(2)









6.48E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Manganese

1.80E-01

mg/L

(2)









8.98E-03

mg/kg-day

2.40E-02

mg/kg-day

0.4







Exp. Route Total







7







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

(2)









2.02E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0002









Cyanide

































Cyanide

3.20E-03

mg/L

(2)









1.09E-06

mg/kg-day

6.00E-04

mg/kg-day

0.002









Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

(2)









7.25E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

1.30E-02

mg/L

(2)









1.14E-06

mg/kg-day

3.00E-04

mg/kg-day

0.004









Manganese

1.80E-01

mg/L

(2)



-





3.96E-05

mg/kg-day

9.60E-04

mg/kg-day

0.04







Exp. Route Total







0.06





Exp. Point Total







7



Exp. Medium Total







7

Medium Total







7

Notes:













Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

7

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-20

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

(2)









1.53E-05

mg/kg-day

1.00E-02

mg/kg-day

0.002









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.60E-05

mg/L

(2)









4.79E-07

mg/kg-day

3.00E-06

mg/kg-day

0.2









Perfluorooctanesulfonic acid (PFOS)

1.50E-04

mg/L

(2)









4.49E-06

mg/kg-day

2.00E-06

mg/kg-day

2









Cyanide

































Cyanide

3.20E-03

mg/L

(2)









9.59E-05

mg/kg-day

6.00E-04

mg/kg-day

0.2









Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

(2)









9.89E-06

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

1.30E-02

mg/L

(2)









3.90E-04

mg/kg-day

3.00E-04

mg/kg-day

1









Manganese

1.80E-01

mg/L

(2)









5.39E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







4







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

(2)









1.34E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0001









Cyanide

































Cyanide

3.20E-03

mg/L

(2)









7.56E-07

mg/kg-day

6.00E-04

mg/kg-day

0.001









Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

(2)









5.52E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

1.30E-02

mg/L

(2)









8.70E-07

mg/kg-day

3.00E-04

mg/kg-day

0.003









Manganese

1.80E-01

mg/L

(2)



-





3.01E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.05





Exp. Point Total







4



Exp. Medium Total







4



Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

4.09E-05

jjg/m3

(2)



-





5.38E-04

jjg/m3

9.77E+01

jjg/m3

0.000006









Cyanide

































Cyanide

1.83E-04

jjg/m3

(2)









2.41E-03

jjg/m3

8.00E-01

jjg/m3

0.003







Exp. Route Total







0.003





Exp. Point Total







0.003



Exp. Medium Total







0.003

Medium Total







4

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

4

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-21

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

6.55E-06

mg/kg-day

3.10E-02

1/(mg/kg-day)

2E-07

(2)

















Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.60E-05

mg/L

2.05E-07

mg/kg-day

7.00E-02

1/(mg/kg-day)

1E-08

(2)

















Perfluorooctanesulfonic acid (PFOS)

1.50E-04

mg/L

1.93E-06

mg/kg-day







(2)

















Cyanide

































Cyanide

3.20E-03

mg/L

4.11E-05

mg/kg-day







(2)

















Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

4.24E-06

mg/kg-day







(2)

















Cobalt

1.30E-02

mg/L

1.67E-04

mg/kg-day







(2)

















Manganese

1.80E-01

mg/L

2.31E-03

mg/kg-day

-





(2)















Exp. Route Total



2E-07











Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

5.10E-04

mg/L

5.64E-07

mg/kg-day

3.10E-02

1/(mg/kg-day)

2E-08

(2)



-













Cyanide

































Cyanide

3.20E-03

mg/L

3.15E-07

mg/kg-day







(2)

















Metals (Total)

































Cadmium (Water)

3.30E-04

mg/L

2.26E-08

mg/kg-day







(2)

















Cobalt

1.30E-02

mg/L

3.56E-07

mg/kg-day







(2)

















Manganese

1.80E-01

mg/L

1.23E-05

mg/kg-day







(2)















Exp. Route Total



2E-08









Exp. Point Total



2E-07







Exp. Medium Total



2E-07







Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

4.09E-05

[jg'm3

1.54E-04

[jg'm3

2.30E-05

m3/|jg

4E-09

(2)

















Cyanide

































Cyanide

1.83E-04

[jg'm3

6.88E-04

[jg'm3







(2)















Exp. Route Total



4E-09









Exp. Point Total



4E-09







Exp. Medium Total



4E-09





Medium Total



2E-07





Notes:















Total of Receptor Risks Across All Media

2E-07

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-22

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

(2)









1.40E-05

mg/kg-day

1.00E-02

mg/kg-day

0.001









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.10E-05

mg/L

(2)









5.48E-07

mg/kg-day

3.00E-06

mg/kg-day

0.2









Perfluorooctanesulfonic acid (PFOS)

5.70E-05

mg/L

(2)









2.84E-06

mg/kg-day

2.00E-06

mg/kg-day

1









Metals (Total)

































Cobalt

1.60E-03

mg/L

(2)









7.98E-05

mg/kg-day

3.00E-04

mg/kg-day

0.3









Copper

2.90E-01

mg/L

(2)









1.45E-02

mg/kg-day

4.00E-02

mg/kg-day

0.4







Exp. Route Total







2







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

(2)









1.11E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0001









Metals (Total)

































Cobalt

1.60E-03

mg/L

(2)









1.41E-07

mg/kg-day

3.00E-04

mg/kg-day

0.0005









Copper

2.90E-01

mg/L

(2)









6.37E-05

mg/kg-day

4.00E-02

mg/kg-day

0.002







Exp. Route Total







0.002





Exp. Point Total







2



Exp. Medium Total







2

Medium Total







2

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

2

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-23

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

(2)









8.39E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0008









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.10E-05

mg/L

(2)









3.30E-07

mg/kg-day

3.00E-06

mg/kg-day

0.1









Perfluorooctanesulfonic acid (PFOS)

5.70E-05

mg/L

(2)









1.71E-06

mg/kg-day

2.00E-06

mg/kg-day

0.9









Metals (Total)

































Cobalt

1.60E-03

mg/L

(2)









4.79E-05

mg/kg-day

3.00E-04

mg/kg-day

0.2









Copper

2.90E-01

mg/L

(2)









8.69E-03

mg/kg-day

4.00E-02

mg/kg-day

0.2







Exp. Route Total







1







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

(2)









7.35E-07

mg/kg-day

1.00E-02

mg/kg-day

0.00007









Metals (Total)

































Cobalt

1.60E-03

mg/L

(2)









1.07E-07

mg/kg-day

3.00E-04

mg/kg-day

0.0004









Copper

2.90E-01

mg/L

(2)









4.85E-05

mg/kg-day

4.00E-02

mg/kg-day

0.001







Exp. Route Total







0.002





Exp. Point Total







1



Exp. Medium Total







1



Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

2.24E-05

jjg/m3

(2)









2.95E-04

jjg/m3

9.77E+01

jjg/m3

0.000003







Exp. Route Total







0.000003





Exp. Point Total







0.000003



Exp. Medium Total







0.000003

Medium Total







1

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

1

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-24

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

3.59E-06

mg/kg-day

3.10E-02

1/(mg/kg-day)

1E-07

(2)

















Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.10E-05

mg/L

1.41E-07

mg/kg-day

7.00E-02

1/(mg/kg-day)

1E-08

(2)

















Perfluorooctanesulfonic acid (PFOS)

5.70E-05

mg/L

7.32E-07

mg/kg-day







(2)

















Metals (Total)

































Cobalt

1.60E-03

mg/L

2.05E-05

mg/kg-day







(2)

















Copper

2.90E-01

mg/L

3.72E-03

mg/kg-day







(2)















Exp. Route Total



1E-07











Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

2.80E-04

mg/L

3.10E-07

mg/kg-day

3.10E-02

1/(mg/kg-day)

1E-08

(2)

















Metals (Total)

































Cobalt

1.60E-03

mg/L

4.39E-08

mg/kg-day

-





(2)

















Copper

2.90E-01

mg/L

1.99E-05

mg/kg-day







(2)



-











Exp. Route Total



1E-08









Exp. Point Total



1E-07







Exp. Medium Total



1E-07







Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

2.24E-05

Ijg'm3

8.44E-05

Ijg'm3

2.30E-05

m3/jj g

2E-09

(2)















Exp. Route Total



2E-09









Exp. Point Total



2E-09







Exp. Medium Total



2E-09





Medium Total



1E-07





Notes:















Total of Receptor Risks Across All Media

1E-07

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-25

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

7.40E-06

mg/L

(2)









3.69E-07

mg/kg-day

3.00E-06

mg/kg-day

0.1









Perfluorooctanesulfonic acid (PFOS)

6.00E-05

mg/L

(2)









2.99E-06

mg/kg-day

2.00E-06

mg/kg-day

1









Metals (Total)

































Cadmium (Water)

2.00E-04

mg/L

(2)









9.97E-06

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

1.80E-03

mg/L

(2)









8.98E-05

mg/kg-day

3.00E-04

mg/kg-day

0.3









Iron

2.90E+00

mg/L

(2)









1.45E-01

mg/kg-day

7.00E-01

mg/kg-day

0.2









Manganese

5.60E-02

mg/L

(2)









2.79E-03

mg/kg-day

2.40E-02

mg/kg-day

0.1







Exp. Route Total







2







Dermal

Metals (Total)

































Cadmium (Water)

2.00E-04

mg/L

(2)









4.39E-08

mg/kg-day

5.00E-06

mg/kg-day

0.009









Cobalt

1.80E-03

mg/L

(2)









1.58E-07

mg/kg-day

3.00E-04

mg/kg-day

0.0005









Iron

2.90E+00

mg/L

(2)









6.37E-04

mg/kg-day

7.00E-01

mg/kg-day

0.0009









Manganese

5.60E-02

mg/L

(2)









1.23E-05

mg/kg-day

9.60E-04

mg/kg-day

0.01







Exp. Route Total







0.02





Exp. Point Total







2



Exp. Medium Total







2

Medium Total







2

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

2

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-26

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

7.40E-06

mg/L

(2)









2.22E-07

mg/kg-day

3.00E-06

mg/kg-day

0.07









Perfluorooctanesulfonic acid (PFOS)

6.00E-05

mg/L

(2)









1.80E-06

mg/kg-day

2.00E-06

mg/kg-day

0.9









Metals (Total)

































Cadmium (Water)

2.00E-04

mg/L

(2)









5.99E-06

mg/kg-day

1.00E-04

mg/kg-day

0.06









Cobalt

1.80E-03

mg/L

(2)









5.39E-05

mg/kg-day

3.00E-04

mg/kg-day

0.2









Iron

2.90E+00

mg/L

(2)









8.69E-02

mg/kg-day

7.00E-01

mg/kg-day

0.1









Manganese

5.60E-02

mg/L

(2)









1.68E-03

mg/kg-day

2.40E-02

mg/kg-day

0.07







Exp. Route Total







1







Dermal

Metals (Total)

































Cadmium (Water)

2.00E-04

mg/L

(2)









3.34E-08

mg/kg-day

5.00E-06

mg/kg-day

0.007









Cobalt

1.80E-03

mg/L

(2)









1.20E-07

mg/kg-day

3.00E-04

mg/kg-day

0.0004









Iron

2.90E+00

mg/L

(2)









4.85E-04

mg/kg-day

7.00E-01

mg/kg-day

0.0007









Manganese

5.60E-02

mg/L

(2)









9.37E-06

mg/kg-day

9.60E-04

mg/kg-day

0.01







Exp. Route Total







0.02





Exp. Point Total







1



Exp. Medium Total







1

Medium Total







1

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

1

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-27

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

7.40E-06

mg/L

9.50E-08

mg/kg-day

7.00E-02

1/(mg/kg-day)

7E-09

(2)

















Perfluorooctanesulfonic acid (PFOS)

6.00E-05

mg/L

7.70E-07

mg/kg-day







(2)

















Metals (Total)

































Cadmium (Water)

2.00E-04

mg/L

2.57E-06

mg/kg-day







(2)

















Cobalt

1.80E-03

mg/L

2.31E-05

mg/kg-day







(2)

















Iron

2.90E+00

mg/L

3.72E-02

mg/kg-day







(2)

















Manganese

5.60E-02

mg/L

7.19E-04

mg/kg-day

-





(2)















Exp. Route Total



7E-09











Dermal

Metals (Total)

Cadmium (Water)

Cobalt

Iron

Manganese

2.00E-04
1.80E-03
2.90E+00
5.60E-02

mg/L
mg/L
mg/L
mg/L

1.37E-08
4.93E-08
1.99E-04
3.84E-06

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)
(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total



7E-09







Exp. Medium Total



7E-09





Medium Total



7E-09





Notes:















Total of Receptor Risks Across All Media

7E-09

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-28

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Metals (Total)

































Barium

6.90E-01

mg/L

(2)









3.44E-02

mg/kg-day

2.00E-01

mg/kg-day

0.2









Beryllium

3.60E-03

mg/L

(2)









1.80E-04

mg/kg-day

2.00E-03

mg/kg-day

0.09









Cadmium (Water)

4.40E-04

mg/L

(2)









2.19E-05

mg/kg-day

1.00E-04

mg/kg-day

0.2









Cobalt

2.60E-02

mg/L

(2)









1.30E-03

mg/kg-day

3.00E-04

mg/kg-day

4









Manganese

1.80E-01

mg/L

(2)









8.98E-03

mg/kg-day

2.40E-02

mg/kg-day

0.4







Exp. Route Total







5







Dermal

Metals (Total)

































Barium

6.90E-01

mg/L

(2)









1.52E-04

mg/kg-day

1.40E-02

mg/kg-day

0.01









Beryllium

3.60E-03

mg/L

(2)









7.91E-07

mg/kg-day

1.40E-05

mg/kg-day

0.06









Cadmium (Water)

4.40E-04

mg/L

(2)









9.67E-08

mg/kg-day

5.00E-06

mg/kg-day

0.02









Cobalt

2.60E-02

mg/L

(2)









2.29E-06

mg/kg-day

3.00E-04

mg/kg-day

0.008









Manganese

1.80E-01

mg/L

(2)









3.96E-05

mg/kg-day

9.60E-04

mg/kg-day

0.04







Exp. Route Total







0.1





Exp. Point Total







5



Exp. Medium Total







5

Medium Total







5

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

5

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-29

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Metals (Total)

































Barium

6.90E-01

mg/L

(2)









2.07E-02

mg/kg-day

2.00E-01

mg/kg-day

0.1









Beryllium

3.60E-03

mg/L

(2)









1.08E-04

mg/kg-day

2.00E-03

mg/kg-day

0.05









Cadmium (Water)

4.40E-04

mg/L

(2)









1.32E-05

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

2.60E-02

mg/L

(2)









7.79E-04

mg/kg-day

3.00E-04

mg/kg-day

3









Manganese

1.80E-01

mg/L

(2)









5.39E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







3







Dermal

Metals (Total)

































Barium

6.90E-01

mg/L

(2)









1.15E-04

mg/kg-day

1.40E-02

mg/kg-day

0.008









Beryllium

3.60E-03

mg/L

(2)









6.02E-07

mg/kg-day

1.40E-05

mg/kg-day

0.04









Cadmium (Water)

4.40E-04

mg/L

(2)









7.36E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

2.60E-02

mg/L

(2)









1.74E-06

mg/kg-day

3.00E-04

mg/kg-day

0.006









Manganese

1.80E-01

mg/L

(2)









3.01E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.1





Exp. Point Total







3



Exp. Medium Total







3

Medium Total







3

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

3

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-30

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Metals (Total)

Barium
Beryllium
Cadmium (Water)
Cobalt
Manganese

6.90E-01
3.60E-03
4.40E-04
2.60E-02
1.80E-01

mg/L
mg/L
mg/L
mg/L
mg/L

8.86E-03
4.62E-05
5.65E-06
3.34E-04
2.31E-03

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)
(2)
(2)
(2)
(2)















Exp. Route Total















Dermal

Metals (Total)

Barium
Beryllium
Cadmium (Water)
Cobalt
Manganese

6.90E-01
3.60E-03
4.40E-04
2.60E-02
1.80E-01

mg/L
mg/L
mg/L
mg/L
mg/L

4.73E-05
2.47E-07
3.02E-08
7.13E-07
1.23E-05

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day

-





(2)
(2)
(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-31

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

(2)









4.79E-05

mg/kg-day

1.00E-02

mg/kg-day

0.005









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.70E-05

mg/L

(2)









8.48E-07

mg/kg-day

3.00E-06

mg/kg-day

0.3









Perfluorooctanesulfonic acid (PFOS)

1.30E-04

mg/L

(2)









6.48E-06

mg/kg-day

2.00E-06

mg/kg-day

3









Metals (Total)

































Cobalt

1.60E-02

mg/L

(2)









7.98E-04

mg/kg-day

3.00E-04

mg/kg-day

3









Manganese

2.60E-01

mg/L

(2)









1.30E-02

mg/kg-day

2.40E-02

mg/kg-day

0.5







Exp. Route Total







7







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

(2)









3.79E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0004









Metals (Total)

































Cobalt

1.60E-02

mg/L

(2)









1.41E-06

mg/kg-day

3.00E-04

mg/kg-day

0.005









Manganese

2.60E-01

mg/L

(2)









5.71E-05

mg/kg-day

9.60E-04

mg/kg-day

0.06







Exp. Route Total







0.06





Exp. Point Total







7



Exp. Medium Total







7

Medium Total







7

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

7

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-32

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

(2)









2.88E-05

mg/kg-day

1.00E-02

mg/kg-day

0.003









Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.70E-05

mg/L

(2)









5.09E-07

mg/kg-day

3.00E-06

mg/kg-day

0.2









Perfluorooctanesulfonic acid (PFOS)

1.30E-04

mg/L

(2)









3.90E-06

mg/kg-day

2.00E-06

mg/kg-day

2









Metals (Total)

































Cobalt

1.60E-02

mg/L

(2)









4.79E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Manganese

2.60E-01

mg/L

(2)









7.79E-03

mg/kg-day

2.40E-02

mg/kg-day

0.3







Exp. Route Total







4







Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

(2)









2.52E-06

mg/kg-day

1.00E-02

mg/kg-day

0.0003









Metals (Total)

































Cobalt

1.60E-02

mg/L

(2)









1.07E-06

mg/kg-day

3.00E-04

mg/kg-day

0.004









Manganese

2.60E-01

mg/L

(2)









4.35E-05

mg/kg-day

9.60E-04

mg/kg-day

0.05







Exp. Route Total







0.05





Exp. Point Total







4



Exp. Medium Total







4



Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

7.69E-05

jjg/m3

(2)









1.01E-03

jjg/m3

9.77E+01

jjg/m3

0.00001







Exp. Route Total







0.00001





Exp. Point Total







0.00001



Exp. Medium Total







0.00001

Medium Total







4

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

4

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-33

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

1.23E-05

mg/kg-day

3.10E-02

1/(mg/kg-day)

4E-07

(2)

















Perfluorinated Compounds

































Perfluorooctanoic acid (PFOA)

1.70E-05

mg/L

2.18E-07

mg/kg-day

7.00E-02

1/(mg/kg-day)

2E-08

(2)

















Perfluorooctanesulfonic acid (PFOS)

1.30E-04

mg/L

1.67E-06

mg/kg-day







(2)

















Metals (Total)

































Cobalt

1.60E-02

mg/L

2.05E-04

mg/kg-day







(2)

















Manganese

2.60E-01

mg/L

3.34E-03

mg/kg-day







(2)















Exp. Route Total



4E-07











Dermal

Volatile Organic Compounds (VOCs)

































Chloroform

9.60E-04

mg/L

1.06E-06

mg/kg-day

3.10E-02

1/(mg/kg-day)

3E-08

(2)

















Metals (Total)

































Cobalt

1.60E-02

mg/L

4.39E-07

mg/kg-day

-





(2)

















Manganese

2.60E-01

mg/L

1.78E-05

mg/kg-day







(2)



-











Exp. Route Total



3E-08









Exp. Point Total



4E-07







Exp. Medium Total



4E-07







Indoor Air

Shower/Bath (Vapors)

Inhalation

Volatile Organic Compounds (VOCs)

































Chloroform

7.69E-05

Ijg'm3

2.89E-04

Ijg'm3

2.30E-05

m3/jj g

7E-09

(2)















Exp. Route Total



7E-09









Exp. Point Total



7E-09







Exp. Medium Total



7E-09





Medium Total



4E-07





Notes:















Total of Receptor Risks Across All Media

4E-07

Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-34

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

1.10E-02

mg/L

(2)









5.48E-04

mg/kg-day

6.00E-04

mg/kg-day

0.9









Metals (Total)

































Barium

1.30E+00

mg/L

(2)









6.48E-02

mg/kg-day

2.00E-01

mg/kg-day

0.3









Cadmium (Water)

3.90E-04

mg/L

(2)









1.94E-05

mg/kg-day

1.00E-04

mg/kg-day

0.2









Cobalt

2.00E-02

mg/L

(2)









9.97E-04

mg/kg-day

3.00E-04

mg/kg-day

3









Copper

1.00E-01

mg/L

(2)









4.99E-03

mg/kg-day

4.00E-02

mg/kg-day

0.1









Manganese

1.40E-01

mg/L

(2)









6.98E-03

mg/kg-day

2.40E-02

mg/kg-day

0.3







Exp. Route Total







5







Dermal

Cyanide

































Cyanide

1.10E-02

mg/L

(2)









3.73E-06

mg/kg-day

6.00E-04

mg/kg-day

0.006









Metals (Total)

































Barium

1.30E+00

mg/L

(2)









2.86E-04

mg/kg-day

1.40E-02

mg/kg-day

0.02









Cadmium (Water)

3.90E-04

mg/L

(2)









8.57E-08

mg/kg-day

5.00E-06

mg/kg-day

0.02









Cobalt

2.00E-02

mg/L

(2)









1.76E-06

mg/kg-day

3.00E-04

mg/kg-day

0.006









Copper

1.00E-01

mg/L

(2)



-





2.20E-05

mg/kg-day

4.00E-02

mg/kg-day

0.0005









Manganese

1.40E-01

mg/L

(2)



-





3.08E-05

mg/kg-day

9.60E-04

mg/kg-day

0.03







Exp. Route Total







0.08





Exp. Point Total







5



Exp. Medium Total







5

Medium Total







5

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

5

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-35

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide

































Cyanide

1.10E-02

mg/L

(2)









3.30E-04

mg/kg-day

6.00E-04

mg/kg-day

0.5









Metals (Total)

































Barium

1.30E+00

mg/L

(2)









3.90E-02

mg/kg-day

2.00E-01

mg/kg-day

0.2









Cadmium (Water)

3.90E-04

mg/L

(2)









1.17E-05

mg/kg-day

1.00E-04

mg/kg-day

0.1









Cobalt

2.00E-02

mg/L

(2)









5.99E-04

mg/kg-day

3.00E-04

mg/kg-day

2









Copper

1.00E-01

mg/L

(2)









3.00E-03

mg/kg-day

4.00E-02

mg/kg-day

0.07









Manganese

1.40E-01

mg/L

(2)









4.20E-03

mg/kg-day

2.40E-02

mg/kg-day

0.2







Exp. Route Total







3







Dermal

Cyanide

































Cyanide

1.10E-02

mg/L

(2)









2.60E-06

mg/kg-day

6.00E-04

mg/kg-day

0.004









Metals (Total)

































Barium

1.30E+00

mg/L

(2)









2.17E-04

mg/kg-day

1.40E-02

mg/kg-day

0.02









Cadmium (Water)

3.90E-04

mg/L

(2)









6.52E-08

mg/kg-day

5.00E-06

mg/kg-day

0.01









Cobalt

2.00E-02

mg/L

(2)









1.34E-06

mg/kg-day

3.00E-04

mg/kg-day

0.004









Copper

1.00E-01

mg/L

(2)









1.67E-05

mg/kg-day

4.00E-02

mg/kg-day

0.0004









Manganese

1.40E-01

mg/L

(2)









2.34E-05

mg/kg-day

9.60E-04

mg/kg-day

0.02







Exp. Route Total







0.06





Exp. Point Total







3



Exp. Medium Total







3



Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

































Cyanide

6.29E-04

jjg/m3

(2)









8.28E-03

jjg/m3

8.00E-01

jjg/m3

0.01







Exp. Route Total







0.01





Exp. Point Total







0.01



Exp. Medium Total







0.01

Medium Total







3

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

3

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-36

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Cyanide
Cyanide
Metals (Total)

Barium

Cadmium (Water)
Cobalt
Copper
Manganese

1.10E-02

1.30E+00
3.90E-04
2.00E-02
1.00E-01
1.40E-01

mg/L

mg/L
mg/L
mg/L
mg/L
mg/L

1.41E-04

1.67E-02
5.01E-06
2.57E-04
1.28E-03
1.80E-03

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)
(2)
(2)
(2)
(2)















Exp. Route Total















Dermal

Cyanide
Cyanide
Metals (Total)

Barium

Cadmium (Water)
Cobalt
Copper
Manganese

1.10E-02

1.30E+00
3.90E-04
2.00E-02
1.00E-01
1.40E-01

mg/L

mg/L
mg/L
mg/L
mg/L
mg/L

1.08E-06

8.91E-05
2.67E-08
5.48E-07
6.85E-06
9.60E-06

mg/kg-day

mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day
mg/kg-day







(2)

(2)
(2)
(2)
(2)
(2)



-











Exp. Route Total













Exp. Point Total











Exp. Medium Total











Indoor Air

Shower/Bath (Vapors)

Inhalation

Cyanide

Cyanide

6.29E-04

Ijg'm3

2.37E-03

Ijg'm3







(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-37

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Child) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Child











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

































Perfluorooctanesulfonic acid (PFOS)

6.50E-05

mg/L

(2)









3.24E-06

mg/kg-day

2.00E-06

mg/kg-day

2









Metals (Total)

































Cobalt

4.40E-03

mg/L

(2)









2.19E-04

mg/kg-day

3.00E-04

mg/kg-day

0.7









Manganese

5.60E-02

mg/L

(2)









2.79E-03

mg/kg-day

2.40E-02

mg/kg-day

0.1







Exp. Route Total







2







Dermal

Metals (Total)

































Cobalt

4.40E-03

mg/L

(2)









3.87E-07

mg/kg-day

3.00E-04

mg/kg-day

0.001









Manganese

5.60E-02

mg/L

(2)









1.23E-05

mg/kg-day

9.60E-04

mg/kg-day

0.01







Exp. Route Total







0.01





Exp. Point Total







2



Exp. Medium Total







2

Medium Total







2

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

2

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-38

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Adult) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Adult











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)
Metals (Total)

6.50E-05

mg/L

(2)









1.95E-06

mg/kg-day

2.00E-06

mg/kg-day

1









Cobalt

4.40E-03

mg/L

(2)









1.32E-04

mg/kg-day

3.00E-04

mg/kg-day

0.4









Manganese

5.60E-02

mg/L

(2)









1.68E-03

mg/kg-day

2.40E-02

mg/kg-day

0.07







Exp. Route Total







1







Dermal

Metals (Total)

































Cobalt

4.40E-03

mg/L

(2)









2.94E-07

mg/kg-day

3.00E-04

mg/kg-day

0.001









Manganese

5.60E-02

mg/L

(2)









9.37E-06

mg/kg-day

9.60E-04

mg/kg-day

0.01







Exp. Route Total







0.01





Exp. Point Total







1



Exp. Medium Total







1

Medium Total







1

Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media

1

(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A7-39

Calculation of Chemical Cancer Risks and Non-Cancer Hazards
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Lifetime) - Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)
Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe:

Current/Future

Receptor Population:

On-Site Resident

Receptor Age:

Lifetime











EPC

Cancer Risk Calculations

Non-Cancer Hazard Calculations

Medium

Exposure Medium

Exposure Point

Exposure Route

Chemical of Potential Concern

Value

Units

Intake/Exposure Concentration

CSF/Unit Risk

Cancer

Intake/Exposure Concentration

RfD/RfC

Hazard











Value

Units

Value

Units

Risk 111

Value

Units

Value

Units

Quotient(1>

Groundwater

Groundwater

Groundwater

Ingestion

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese

6.50E-05

4.40E-03
5.60E-02

mg/L

mg/L
mg/L

8.34E-07

5.65E-05
7.19E-04

mg/kg-day

mg/kg-day
mg/kg-day







(2)

(2)
(2)















Exp. Route Total















Dermal

Metals (Total)

Cobalt
Manganese

4.40E-03
5.60E-02

mg/L
mg/L

1.21E-07
3.84E-06

mg/kg-day
mg/kg-day







(2)
(2)















Exp. Route Total













Exp. Point Total











Exp. Medium Total









Medium Total









Notes:















Total of Receptor Risks Across All Media



Total of Receptor Hazards Across All Media



(1)	CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

(2)	Cancer risk is only presented for the lifetime receptor, whereas non-cancer hazard is calculated separately for the child and adult receptor.

-------
Table A9-1

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Copper

Manganese









DV

RP

NV
EN
Gl
NV

0.3

0.4

0.1
5

0.3
0.4

0.003

0.008
0.009
0.001
0.04



0.3

0.4

0.1
5

0.3
0.4







Chemical Total











6

0.06



7





Exposure Point Total





7



Exposure Medium Total





7

Medium Total





7

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

7

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

0.3

Total Endocrine (EN) HI across All Media =

5

Total Gastrointestinal (Gl) HI across All Media =

0.3

Total Nervous (NV) HI across All Media =

0.6

Total Reproductive (RP) HI across All Media =

0.4

-------
Table A9-2

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Copper

Manganese









DV

RP

NV
EN
Gl
NV

0.2

0.2

0.07
3

0.2
0.2

0.002

0.006
0.007
0.001
0.03



0.2

0.2

0.08
3

0.2
0.3







Chemical Total











4

0.05



4





Exposure Point Total





4



Exposure Medium Total





4



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.004

0.004







Chemical Total















0.004

0.004





Exposure Point Total





0.004



Exposure Medium Total





0.004

Medium Total





4

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

4

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

0.2

Total Endocrine (EN) HI across All Media =

3

Total Gastrointestinal (Gl) HI across All Media =

0.2

Total Nervous (NV) HI across All Media =

0.3

Total Reproductive (RP) HI across All Media =

0.2

-------
Table A9-3

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0124)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Copper

Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total









Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-4

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Arsenic
Barium

Cadmium (Water)
Cobalt
Copper
Manganese









RP

DM; HM
NV
UR
EN
Gl
NV

0.4

0.06
0.3
0.2
2

0.2
0.2

0.003

0.0003
0.02
0.01
0.004
0.0008
0.03



0.4

0.06
0.3
0.2
2

0.2
0.3







Chemical Total











4

0.07



4





Exposure Point Total





4



Exposure Medium Total





4

Medium Total





4

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

4

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Dermal (DM) HI across All Media =

0.06

Total Endocrine (EN) HI across All Media =

2

Total Gastrointestinal (Gl) HI across All Media =

0.2

Total Hematological (HM) HI across All Media =

0.06

Total Nervous (NV) HI across All Media =

0.6

Total Reproductive (RP) HI across All Media =

0.4

Total Urinary (UR) HI across All Media =

0.2

-------
Table A9-5

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Arsenic
Barium

Cadmium (Water)
Cobalt
Copper
Manganese









RP

DM; HM
NV
UR
EN
Gl
NV

0.2

0.04
0.2
0.1
1

0.1
0.1

0.002

0.0002
0.01
0.01
0.003
0.0006
0.02



0.2

0.04
0.2
0.1
2

0.1
0.2







Chemical Total











2

0.05



2





Exposure Point Total





2



Exposure Medium Total





2



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.005

0.005







Chemical Total















0.005

0.005





Exposure Point Total





0.005



Exposure Medium Total





0.005

Medium Total





2

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

2

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Dermal (DM) HI across All Media =

0.04

Total Endocrine (EN) HI across All Media =

2

Total Gastrointestinal (Gl) HI across All Media =

0.1

Total Hematological (HM) HI across All Media =

0.04

Total Nervous (NV) HI across All Media =

0.3

Total Reproductive (RP) HI across All Media =

0.2

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-6

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0155)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Arsenic
Barium

Cadmium (Water)
Cobalt
Copper
Manganese

7E-06

4E-08



7E-06

















Chemical Total

7E-06

4E-08



7E-06















Exposure Point Total

7E-06







Exposure Medium Total

7E-06







Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total

7E-06





Notes:









Receptor Risk Total

7E-06

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-7

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Chromium, Hexavalent

Cobalt

Nickel









HP

DV
DV

EN
OT

0.007

0.2
6

0.1
1

0.1

0.0006

0.03
0.002
0.003



0.008

0.2
6

0.1
1

0.1







Chemical Total











8

0.04



8





Exposure Point Total





8



Exposure Medium Total





8



Indoor Air

Indoor Air
(Vapor Intrusion)

Volatile Organic Compounds (VOCs)

Chloroform









HP





0.002

0.002







Chemical Total















0.002

0.002





Exposure Point Total





0.002



Exposure Medium Total





0.002

Medium Total





8

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

8

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

7

Total Endocrine (EN) HI across All Media =

1

Total Hepatic (HP) HI across All Media =

0.009

Total Other (OT) HI across All Media =

0.1

-------
Table A9-8

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Chromium, Hexavalent

Cobalt

Nickel









HP

DV
DV

EN
OT

0.004

0.1
4

0.06
0.6
0.08

0.0004

0.03
0.001
0.002



0.005

0.1
4

0.08
0.7
0.08







Chemical Total











5

0.03



5





Exposure Point Total





5



Exposure Medium Total





5



Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform









HP





0.00002

0.00002







Chemical Total















0.00002

0.00002





Exposure Point Total





0.00002



Exposure Medium Total





0.00002





Indoor Air
(Vapor Intrusion)

Volatile Organic Compounds (VOCs)

Chloroform









HP





0.002

0.002







Chemical Total















0.002

0.002





Exposure Point Total





0.002



Exposure Medium Total





0.002

Medium Total





5

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

5

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

4

Total Endocrine (EN) HI across All Media =

0.7

Total Hepatic (HP) HI across All Media =

0.006

Total Other (OT) HI across All Media =

0.08

-------
Table A9-9

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0170)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Chromium, Hexavalent

Cobalt

Nickel

6E-07
1E-08

1E-04

5E-08
5E-05



6E-07
1E-08

2E-04

















Chemical Total

1E-04

5E-05



2E-04















Exposure Point Total

2E-04







Exposure Medium Total

2E-04







Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform





1E-08

1E-08

















Chemical Total





1E-08

1E-08















Exposure Point Total

1E-08







Exposure Medium Total

1E-08









Indoor Air
(Vapor Intrusion)

Volatile Organic Compounds (VOCs)

Chloroform





1E-06

1E-06

















Chemical Total





1E-06

1E-06















Exposure Point Total

1E-06







Exposure Medium Total

1E-06





Medium Total

2E-04





Notes:









Receptor Risk Total

2E-04

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-10

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Manganese









DV

RP

NV
EN
NV

0.6

0.8

0.1
4

0.5

0.005

0.007
0.006
0.05



0.6

0.8

0.1
4

0.5







Chemical Total











6

0.07



6





Exposure Point Total





6



Exposure Medium Total





6

Medium Total





6

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

6

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

0.6

Total Endocrine (EN) HI across All Media =

4

Total Nervous (NV) HI across All Media =

0.6

Total Reproductive (RP) HI across All Media =

0.8

-------
Table A9-11

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Manganese









DV

RP

NV
EN
NV

0.4

0.5

0.06
2

0.3

0.004

0.005
0.005
0.04



0.4

0.5

0.07
2

0.3







Chemical Total











3

0.05



3





Exposure Point Total





3



Exposure Medium Total





3



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.009

0.009







Chemical Total















0.009

0.009





Exposure Point Total





0.009



Exposure Medium Total





0.009

Medium Total





3

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

3

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

0.4

Total Endocrine (EN) HI across All Media =

2

Total Nervous (NV) HI across All Media =

0.4

Total Reproductive (RP) HI across All Media =

0.5

-------
Table A9-12

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0173)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Barium

Cobalt

Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total









Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-13

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)

Cobalt

Manganese









RP

NV
UR
EN
NV

0.7

0.1
0.1
2

0.3

0.005

0.007
0.009
0.004
0.04



0.8

0.1
0.1
2

0.4







Chemical Total











4

0.06



4





Exposure Point Total





4



Exposure Medium Total





4

Medium Total





4

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

4

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

2

Total Nervous (NV) HI across All Media =

0.5

Total Reproductive (RP) HI across All Media =

0.8

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-14

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)

Cobalt

Manganese









RP

NV
UR
EN
NV

0.4

0.06
0.06
1

0.2

0.004

0.005
0.007
0.003
0.03



0.5

0.07
0.07
1

0.2







Chemical Total











2

0.05



2





Exposure Point Total





2



Exposure Medium Total





2



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.008

0.008







Chemical Total















0.008

0.008





Exposure Point Total





0.008



Exposure Medium Total





0.008

Medium Total





2

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

2

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

1

Total Nervous (NV) HI across All Media =

0.3

Total Reproductive (RP) HI across All Media =

0.5

Total Urinary (UR) HI across All Media =

0.07

-------
Table A9-15

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0176)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)

Cobalt

Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total









Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-16

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cobalt

Manganese









DV
DV

RP

EN
NV

0.2
5

0.3
4

0.8

0.002

0.007
0.09



0.2
5

0.3
4

0.9







Chemical Total











11

0.1



11





Exposure Point Total





11



Exposure Medium Total





11

Medium Total





11

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

11

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

6

Total Endocrine (EN) HI across All Media =

4

Total Nervous (NV) HI across All Media =

0.9

Total Reproductive (RP) HI across All Media =

0.3

-------
Table A9-17

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cobalt

Manganese









DV
DV

RP

EN
NV

0.1
3

0.2
2

0.5

0.001

0.006
0.07



0.1
3

0.2
3

0.5







Chemical Total











7

0.07



7





Exposure Point Total





7



Exposure Medium Total





7



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.003

0.003







Chemical Total















0.003

0.003





Exposure Point Total





0.003



Exposure Medium Total





0.003

Medium Total





7

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

7

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

3

Total Endocrine (EN) HI across All Media =

3

Total Nervous (NV) HI across All Media =

0.5

Total Reproductive (RP) HI across All Media =

0.2

-------
Table A9-18

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0182)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cobalt

Manganese

1E-08





1E-08

















Chemical Total

1E-08





1E-08















Exposure Point Total

1E-08







Exposure Medium Total

1E-08







Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total

1E-08





Notes:









Receptor Risk Total

1E-08

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-19

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cadmium (Water)

Cobalt

Manganese









HP

DV
DV

RP

UR
EN
NV

0.003

0.3
4

0.3

0.2
2

0.4

0.0002

0.002

0.01
0.004
0.04



0.003

0.3
4

0.3

0.2
2

0.4







Chemical Total











7

0.06



7





Exposure Point Total





7



Exposure Medium Total





7

Medium Total





7

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

7

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

4

Total Endocrine (EN) HI across All Media =

2

Total Hepatic (HP) HI across All Media =

0.003

Total Nervous (NV) HI across All Media =

0.4

Total Reproductive (RP) HI across All Media =

0.3

Total Urinary (UR) HI across All Media =

0.2

-------
Table A9-20

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cadmium (Water)

Cobalt

Manganese









HP

DV
DV

RP

UR
EN
NV

0.002

0.2
2

0.2

0.1
1

0.2

0.0001

0.001

0.01
0.003
0.03



0.002

0.2
2

0.2

0.1
1

0.3







Chemical Total











4

0.05



4





Exposure Point Total





4



Exposure Medium Total





4



Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform
Cyanide

Cyanide









HP
EN





0.000006
0.003

0.000006
0.003







Chemical Total















0.003

0.003





Exposure Point Total





0.003



Exposure Medium Total





0.003

Medium Total





4

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

4

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

2

Total Endocrine (EN) HI across All Media =

1

Total Hepatic (HP) HI across All Media =

0.002

Total Nervous (NV) HI across All Media =

0.3

Total Reproductive (RP) HI across All Media =

0.2

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-21

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0197)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Cyanide

Cyanide

Metals (Total)

Cadmium (Water)

Cobalt

Manganese

2E-07
1E-08

2E-08



2E-07
1E-08

















Chemical Total

2E-07

2E-08



2E-07















Exposure Point Total

2E-07







Exposure Medium Total

2E-07







Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform
Cyanide

Cyanide





4E-09

4E-09

















Chemical Total





4E-09

4E-09















Exposure Point Total

4E-09







Exposure Medium Total

4E-09





Medium Total

2E-07





Notes:









Receptor Risk Total

2E-07

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-22

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Copper









HP

DV
DV

EN
Gl

0.001

0.2
1

0.3
0.4

0.0001

0.0005
0.002



0.002

0.2
1

0.3
0.4







Chemical Total











2

0.002



2





Exposure Point Total





2



Exposure Medium Total





2

Medium Total





2

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

2

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

2

Total Endocrine (EN) HI across All Media =

0.3

Total Gastrointestinal (Gl) HI across All Media =

0.4

Total Hepatic (HP) HI across All Media =

0.002

-------
Table A9-23

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Copper









HP

DV
DV

EN
Gl

0.0008

0.1
0.9

0.2
0.2

0.00007

0.0004
0.001



0.0009

0.1
0.9

0.2
0.2







Chemical Total











1

0.002



1





Exposure Point Total





1



Exposure Medium Total





1



Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform









HP





0.000003

0.000003







Chemical Total















0.000003

0.000003





Exposure Point Total





0.000003



Exposure Medium Total





0.000003

Medium Total





1

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

1

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

1

Total Endocrine (EN) HI across All Media =

0.2

Total Gastrointestinal (Gl) HI across All Media =

0.2

Total Hepatic (HP) HI across All Media =

0.0009

-------
Table A9-24

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0212)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Copper

1E-07
1E-08

1E-08



1E-07
1E-08

















Chemical Total

1E-07

1E-08



1E-07















Exposure Point Total

1E-07







Exposure Medium Total

1E-07







Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform





2E-09

2E-09

















Chemical Total





2E-09

2E-09















Exposure Point Total

2E-09







Exposure Medium Total

2E-09





Medium Total

1E-07





Notes:









Receptor Risk Total

1E-07

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-25

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cadmium (Water)

Cobalt

Iron

Manganese









DV
DV

UR
EN
Gl
NV

0.1
1

0.1
0.3
0.2
0.1

0.009
0.0005
0.0009
0.01



0.1
1

0.1
0.3
0.2
0.1







Chemical Total











2

0.02



2





Exposure Point Total





2



Exposure Medium Total





2

Medium Total





2

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

2

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

2

Total Endocrine (EN) HI across All Media =

0.3

Total Gastrointestinal (Gl) HI across All Media =

0.2

Total Nervous (NV) HI across All Media =

0.1

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-26

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cadmium (Water)

Cobalt

Iron

Manganese









DV
DV

UR
EN
Gl
NV

0.07
0.9

0.06
0.2
0.1
0.07

0.007
0.0004
0.0007
0.01



0.07
0.9

0.07
0.2
0.1
0.08







Chemical Total











1

0.02



1





Exposure Point Total





1



Exposure Medium Total





1

Medium Total





1

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

1

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

1

Total Endocrine (EN) HI across All Media =

0.2

Total Gastrointestinal (Gl) HI across All Media =

0.1

Total Nervous (NV) HI across All Media =

0.08

Total Urinary (UR) HI across All Media =

0.07

-------
Table A9-27

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0275)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cadmium (Water)

Cobalt

Iron

Manganese

7E-09





7E-09

















Chemical Total

7E-09





7E-09















Exposure Point Total

7E-09







Exposure Medium Total

7E-09





Medium Total

7E-09





Notes:









Receptor Risk Total

7E-09

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-28

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Metals (Total)

Barium
Beryllium
Cadmium (Water)
Cobalt
Manganese









NV
Gl
UR
EN
NV

0.2
0.09
0.2
4

0.4

0.01
0.06
0.02
0.008
0.04



0.2
0.1
0.2
4

0.4







Chemical Total











5

0.1



5





Exposure Point Total





5



Exposure Medium Total





5

Medium Total





5

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

5

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

4

Total Gastrointestinal (Gl) HI across All Media =

0.1

Total Nervous (NV) HI across All Media =

0.6

Total Urinary (UR) HI across All Media =

0.2

-------
Table A9-29

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Metals (Total)

Barium
Beryllium
Cadmium (Water)
Cobalt
Manganese









NV
Gl
UR
EN
NV

0.1
0.05
0.1
3

0.2

0.008
0.04
0.01
0.006
0.03



0.1
0.1
0.1
3

0.3







Chemical Total











3

0.1



3





Exposure Point Total





3



Exposure Medium Total





3

Medium Total





3

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

3

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

3

Total Gastrointestinal (Gl) HI across All Media =

0.1

Total Nervous (NV) HI across All Media =

0.4

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-30

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0500)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Metals (Total)

Barium
Beryllium
Cadmium (Water)
Cobalt
Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-31

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese









HP

DV
DV

EN
NV

0.005

0.3
3

3

0.5

0.0004

0.005
0.06



0.005

0.3
3

3

0.6







Chemical Total











7

0.06



7





Exposure Point Total





7



Exposure Medium Total





7

Medium Total





7

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

7

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

4

Total Endocrine (EN) HI across All Media =

3

Total Hepatic (HP) HI across All Media =

0.005

Total Nervous (NV) HI across All Media =

0.6

-------
Table A9-32

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese









HP

DV
DV

EN
NV

0.003

0.2
2

2

0.3

0.0003

0.004
0.05



0.003

0.2
2

2

0.4







Chemical Total











4

0.05



4





Exposure Point Total





4



Exposure Medium Total





4



Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform









HP





0.00001

0.00001







Chemical Total















0.00001

0.00001





Exposure Point Total





0.00001



Exposure Medium Total





0.00001

Medium Total





4

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

4

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

2

Total Endocrine (EN) HI across All Media =

2

Total Hepatic (HP) HI across All Media =

0.003

Total Nervous (NV) HI across All Media =

0.4

-------
Table A9-33

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0501)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Volatile Organic Compounds (VOCs)

Chloroform

Perfluorinated Compounds

Perfluorooctanoic acid (PFOA)

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese

4E-07
2E-08

3E-08



4E-07
2E-08

















Chemical Total

4E-07

3E-08



4E-07















Exposure Point Total

4E-07







Exposure Medium Total

4E-07







Indoor Air

Shower/Bath (Vapors)

Volatile Organic Compounds (VOCs)

Chloroform





7E-09

7E-09

















Chemical Total





7E-09

7E-09















Exposure Point Total

7E-09







Exposure Medium Total

7E-09





Medium Total

4E-07





Notes:









Receptor Risk Total

4E-07

Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-34

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)
Cobalt
Copper
Manganese









RP

NV
UR
EN
Gl
NV

0.9

0.3
0.2
3

0.1
0.3

0.006

0.02
0.02
0.006
0.0005
0.03



0.9

0.3
0.2
3

0.1
0.3







Chemical Total











5

0.08



5





Exposure Point Total





5



Exposure Medium Total





5

Medium Total





5

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

5

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

3

Total Gastrointestinal (Gl) HI across All Media =

0.1

Total Nervous (NV) HI across All Media =

0.7

Total Reproductive (RP) HI across All Media =

0.9

Total Urinary (UR) HI across All Media =

0.2

-------
Table A9-35

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)
Cobalt
Copper
Manganese









RP

NV
UR
EN
Gl
NV

0.5

0.2
0.1
2
0.07
0.2

0.004

0.02
0.01
0.004
0.0004
0.02



0.6

0.2
0.1
2
0.08
0.2







Chemical Total











3

0.06



3





Exposure Point Total





3



Exposure Medium Total





3



Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide









EN





0.01

0.01







Chemical Total















0.01

0.01





Exposure Point Total





0.01



Exposure Medium Total





0.01

Medium Total





3

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

3

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Endocrine (EN) HI across All Media =

2

Total Gastrointestinal (Gl) HI across All Media =

0.08

Total Nervous (NV) HI across All Media =

0.4

Total Reproductive (RP) HI across All Media =

0.6

Total Urinary (UR) HI across All Media =

0.1

-------
Table A9-36

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0510)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Cyanide

Cyanide
Metals (Total)

Barium

Cadmium (Water)
Cobalt
Copper
Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total









Indoor Air

Shower/Bath (Vapors)

Cyanide

Cyanide

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
Table A9-37

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Child) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Child









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese









DV

EN
NV

2

0.7
0.1

0.001
0.01



2

0.7
0.1







Chemical Total











2

0.01



2





Exposure Point Total





2



Exposure Medium Total





2

Medium Total





2

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

2

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

2

Total Endocrine (EN) HI across All Media =

0.7

Total Nervous (NV) HI across All Media =

0.1

-------
Table A9-38

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Adult) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Adult









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese









DV

EN
NV

1

0.4
0.07

0.001
0.01



1

0.4
0.08







Chemical Total











1

0.01



1





Exposure Point Total





1



Exposure Medium Total





1

Medium Total





1

Notes:









Receptor Risk Total



Receptor Hazard Index (HI)

1

(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

Total Developmental (DV) HI across All Media =

1

Total Endocrine (EN) HI across All Media =

0.4

Total Nervous (NV) HI across All Media =

0.08

-------
Table A9-39

Summary of Chemical Cancer Risks and Non-Cancer Hazards for COPCs
Reasonable Maximum Exposure (Well 0527)

Current/Future On-Site Resident (Lifetime) ¦ Groundwater, Groundwater (Potable Use), Groundwater (Vapor Intrusion)

Human Health Risk Assessment
Blades Groundwater Superfund Site, Blades, Delaware

Scenario Timeframe: Current/Future
Receptor Population: On-Site Resident
Receptor Age:	Lifetime









Thresholds: Chemical-specific (1E-06) and Cumulative (1E-04)

Thresholds: Chemical-specific, Target Organ and Cumulative (HQ > 1)

Medium

Exposure Medium

Exposure Point

Chemical of Potential Concern

Carcinogenic Risk(1)

Non-Carcinogenic Hazard Quotient<1>





Ingestion

Dermal

Inhalation

Exposure Routes
Total

Primary Target Organs

Ingestion

Dermal

Inhalation

Exposure Routes
Total

Groundwater

Groundwater

Groundwater

Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

Metals (Total)

Cobalt

Manganese

























Chemical Total























Exposure Point Total









Exposure Medium Total







Medium Total







Notes:









Receptor Risk Total



Receptor Hazard Index (HI)



(1) CR and HQs are rounded to one non-zero digit; cumulative totals may be slightly higher or lower depending on degree of rounding.

-------
APPENDIX D
DETAILED COST ESTIMATE

-------






Planning Cost Estimate Summary



Alternative: OU2-5: Alternate Water Supply-Waterline Connection









Site: Blades OU-2 (Residential)







Description:

This alternative involves connecting to the existing Town of Blades water distribution system and

Location: Blades, Delaware











extending that system into the affected area. Monthly billing costs covered by end users

Phase: FS











following water line connection.

Date: February 2023

















CAPITAL COSTS

















Description







QTY

UNIT

UNIT COST

Total

Notes

Site Preparation and Management

















RA Contractor Work Plan







1

LS

$20,000

$20,000

Allowance

HASP







1

LS

$10,000

$10,000

Allowance

Equipment mobilization







1

LS

$20,000

$20,000

Allowance















$50,000



Additional Costs Associated with Existing POET/POUT Systems















Carbon unit added for POETs







5

each

$1,350

$6,750

For existing number of residences;

cost per unit from Active Chemical 8/12/22 estimate

Carbon unit added for POUTs







15

each

$50

$750

For existing number of units (15 total in 7 residences);
cost per unit assumed

Oversight







29

HR

$75

$2,175

Assume 3 hrs per existing POET residence for carbon addition;
assume 2 hrs per existing POUT residence for carbon addition















$9,675



General Assumptions

















Number of houses to connect

70

houses













Test Pits at intersections

28

ea











2 per intersection assumed

6" Water Main

8,750

ft











Length of roadways in area of connection

Rock Removal

194

cy











Assumes 20% of route @ 3 ft deep

1" Supply from property line to house

7,000

ft











Assumes average of 100 ft/house

Sawcutting Bituminous Pavement

17,500

ft











2 cuts for total length of 6" water main

Removal of Bituminous Pavement

6,806

sy











Assumes 3.5 ft width of cut

Permanent Pavement Repair (Mill & Overlay)

23,333

sy











Assume 3" depth, 24' width for length of 6" water main

Driveway Repair/Replacement

486

sy











Assume 25% of houses * 250 sf/house

Pavement Markings

3,261

ft











Affected length of River Road

Turf Establishment

1,750

sy











Assume 100 sf/house+1 ft width along length of 6" water main

Hydrants

11

ea











Maximum spacing of 800 ft (estimate by dividing 6" water main
length by 800 ft)

Water Line Construction and Existing System/Well Removal/Abandonment













Erosion and Sediment Control Systems







1

LS

$20,000

$20,000

Allowance

Dust control and air monitoring







100

DAY

$1,000

$100,000

Estimated cost per day over assumed 5 months (20 days/mo)

Maintenance & Protection of Traffic







1,600

HR

$50

$80,000

Assumes 2 police for 100 8-hr days

Test Pits







28

EA

$500

$14,000

Unit Cost from RM 10/18/22 estimate

Connect to Blades Water Main and place under RR tracks







50

LF

$1,000

$50,000

Jacking under RR track; unit cost from RM 10/20/22 estimate

Rock Removal







194

CY

$75

$14,583

Unit Cost from RM 10/18/22 estimate

6" Ductile Iron Pipe (DIP) Water Main







8,750

FT

$175

$1,531,250

Unit Cost from RM 10/18/22 estimate

Wedge Blowoff







3

EA

$3,200

$9,600

Unit Cost from RM 10/20/22 estimate

6" gate valve and box







14

EA

$3,000

$42,000

Unit Cost from RM 10/20/22 estimate

1" Copper water service connection







70

EA

$550

$38,500

Unit Cost from RM 10/20/22 estimate

1" Supply from property line to house







7,000

FT

$33

$231,000

Unit Cost from RM 10/18/22 estimate

1" Water meter







70

EA

$300

$21,000

Unit Cost from RM 10/20/22 estimate

Dewatering







1

LS

$15,000

$15,000

Allowance

Sawcutting Bituminous Pavement







17,500

FT

$4

$70,000

Unit Cost from RM 10/18/22 estimate

Removal of Bituminous Pavement







6,806

SY

$12

$81,667

Unit Cost from RM 10/18/22 estimate

Temporary Pavement Repair







6,806

SY

$20

$136,111

Unit Cost from RM 10/20/22 estimate

Permanent Pavement Repair (Mill & Overlay)







23,333

SY

$25

$583,333

Unit Cost from RM 10/18/22 estimate

Driveway Repair/Replacement







486

SY

$25

$12,153

Unit Cost from RM 10/20/22 estimate

Pavement Markings







3,261

FT

$1.5

$4,892

Unit Cost from RM 10/18/22 estimate

Turf Establishment







1,750

SY

$18

$31,500

Unit Cost from RM 10/18/22 estimate

Hydrants, including appurtenances







11

EA

$12,400

$135,625

Unit Cost from RM 10/18/22 estimate

Disinfection of water main







1

LS

$15,000

$15,000

Unit Cost from Durham FS

Pressure and leakage tests







1

LS

$10,000

$10,000

Unit Cost from Durham FS

Water Line Construction Oversight







800

HR

$75

$60,000

Assume 5 mos (20 days/mo) for 8 hrs/day

Well Abandonment







70

each

$600

$42,000

Assume $12/ft; assume 50 ft/well ($600/well)

Well Abandonment Oversight







560

HR

$75

$42,000

Assume 8 hrs per property to abandon/restore

Remove existing POET/POUT systems







20

each

$500

$10,000

Assume up to 20 residences; includes oversight; cost from vendor
discussion















$3,401,214



Post-Construction

















Remedial Action Completion Report







200

HR

$100

$20,000

Assumes 3 iterations for regulatory review/comment















$20,000



SUBTOTAL













$3,480,889

















$1,044,267

Typically just presumed scope (10%)+ bid(10%); however with

Contingency





30%







current economic supply conditions add another 10%

SUBTOTAL













$4,525,155



Project Management





6%







$271,509

Per USACE/USEPA Guide to Developing CEs during the FS

Remedial Design





10%







$452,516

Use maximum allowed for design services (10%)

Construction Management





8%







$362,012

Per USACE/USEPA Guide to Developing CEs during the FS

TOTAL CAPITAL COSTS (rounded to the nearest $1,000)













| $5,611,000

1

Page 1 of 3

-------


Planning Cost Estimate Summary



Alternative: OU2-5: Alternate Water Supply-Waterline Connection









O&M COSTS













Description



QTY

UNIT

UNIT COST

Total

Notes

Filter/Media Replacement/Maintenance (Annual)













POET Filter replacement (2 times/yr) $192 per event











Cost from bid analysis worksheet dated 4/29/22

POET Media replacement (every 3 years) $224 per event (use 1/3 for annual cost)







Cost from bid analysis worksheet dated 4/29/22













Replacement frequency assumed; cost from Active Chemical

POET carbon replacement (assume 1 time/yr) $850 per event











8/12/22 estimate

POUT Filter replacement (1 time/yr) $41 per event











Cost from bid analysis worksheet dated 4/29/22

POUT carbon replacement (assume 1 time/yr) $50 per event











Replacement frequency and cost assumed

POE Systems (Filter - 2 times per year; Media - every 3 years)



5

each

$1,309

$6,543

Unit Cost = 2* POE Filter Replacement+l/3*POE Media
Replacement

POU Systems (Filter - 1 time per year)



15

each

$91

$1,365

General Maintenance (assume 4 hrs per residence annually)



48

Hr

$75

$3,600

Responding to calls related to system issues (12 residences) for 3
years

SUBTOTAL









$11,508



Contingency

10%







$1,151



Project Management

10%







$1,151



COST PER ANNUAL FILTER/MEDIA REPLACEMENT









$13,810



Residential Monitoring: Labor & Materials











Annual monitoring assumed

Field work



80

HR

$75

$6,000

Assume 3 days+1 day of prep, 2 people, (8 total 10-hr days)

Brief memo summarizing maintenance and annual monitoring results



20

HR

$105

$2,100

Allowance

Letters to each resident



12

HR

$75

$900

Assume 1 hr per letter

Misc supplies, copying, etc.



1

LS

$1,000

$1,000

Allowance

Residential Monitoring: Analytical (first 2 years)











First 2 years - all analytes

PFAS



20

per sample

$282

$5,630

Recent avg. lab cost per sample

TAL Metals



20

per sample

$85

$1,700

Recent avg. lab cost per sample

Hexavalent Chromium



20

per sample

$85

$1,700

Recent avg. lab cost per sample

PAHs



20

per sample

$125

$2,500

Recent avg. lab cost per sample

VOCs



20

per sample

$62

$1,240

Recent avg. lab cost per sample

DO, ORP, pH, Cond., Temp.(field)



20

per sample

$10

$200

Recent avg. lab cost per sample

15% QA/QC



1

LS

$1,946

$1,946

Allowance of 15%

SUBTOTAL









$24,916



Contingency

10%







$2,492



Project Management

10%







$2,492



COST PER RESIDENTIAL EVENT (first 2 years)









$29,899



Residential Monitoring: Analytical (year 3)











Year 3 - remove VOCs and PAHs

PFAS



20

per sample

$282

$5,630

Recent avg. lab cost per sample

TAL Metals



20

per sample

$85

$1,700

Recent avg. lab cost per sample

Hexavalent Chromium



20

per sample

$85

$1,700

Recent avg. lab cost per sample

PAHs



0

per sample

$125

$0

Recent avg. lab cost per sample

VOCs



0

per sample

$62

$0

Recent avg. lab cost per sample

DO, ORP, pH, Cond., Temp.(field)



20

per sample

$10

$200

Recent avg. lab cost per sample

15% QA/QC



1

LS

$1,385

$1,385

Allowance of 15%

SUBTOTAL









$20,615



Contingency

10%







$2,061



Project Management

10%







$2,061



COST PER RESIDENTIAL EVENT (year 3)









$24,737



TOTAL O&M ANNUAL COSTS (rounded to the nearest $1,000) - First 2 Years









$44,000

Filter/Media Replacement and Resid. Monitoring (first 2 years)

TOTAL O&M ANNUAL COSTS (rounded to the nearest $1,000) - Year 3









$39,000

Filter/Media Replacement and Resid. Monitoring (Year 3)

TOTAL O&M ANNUAL COSTS (rounded to the nearest $1,000) - After Year 3









$0



PERIODIC COSTS













Description



QTY

UNIT

UNIT COST

Total

Notes

Five Year Review (through year 30)



0

each

$20,000

$0

Will be included in post-RI remedial alternatives.

SUBTOTAL









$0



TOTAL PERIODIC ANNUAL COSTS (rounded to the nearest $1,000)









$0



PRESENT VALUE ANALYSIS



Straight Cost



| Present Value



Discount „ . , „
Year Capital Cost
Factor at

O&M Costs

Periodic Costs

O&M

Periodic

Notes

Cost Type 0.50%













Capital Cost 0 1 | $5,611,000 |









Discount rate of 0.5% is based on the March 15, 2022













30-Year Real Interest Rate in Appendix C













of the White House Office of Management













and Budget (OMB) Circular A-94, Revised













March 15, 2022

O&M Cost and Periodic Costs 1 0.9950



$44,000



$43,781

$0

O&M -POETS/POUTS Maintenance and Monitoring

2 0.9901



$44,000



$43,563

$0

O&M -POETS/POUTS Maintenance and Monitoring

3 0.9851



$39,000



$38,421

$0

O&M -POETS/POUTS Maintenance and Monitoring

4 0.9802



$0



$0

$0



5 0.9754



$0

$0

$0

$0



6 0.9705



$0



$0

$0



7 0.9657



$0



$0

$0



8 0.9609



$0



$0

$0



9 0.9561



$0



$0

$0



Page 2 of 3

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Planning Cost Estimate Summary

Alternative:	OU2-5: Alternate Water Supply-Waterline Connection

10

0.9513

$0

$0

$0

$0

11

0.9466

$0



$0

$0

12

0.9419

$0



$0

$0

13

0.9372

$0



$0

$0

14

0.9326

$0



$0

$0

15

0.9279

$0

$0

$0

$0

16

0.9233

$0



$0

$0

17

0.9187

$0



$0

$0

18

0.9141

$0



$0

$0

19

0.9096

$0



$0

$0

20

0.9051

$0

$0

$0

$0

21

0.9006

$0



$0

$0

22

0.8961

$0



$0

$0

23

0.8916

$0



$0

$0

24

0.8872

$0



$0

$0

25

0.8828

$0

$0

$0

$0

26

0.8784

$0



$0

$0

27

0.8740

$0



$0

$0

28

0.8697

$0



$0

$0

29

0.8653

$0



$0

$0

30

0.8610

$0

$0

$0

$0

| $126,000 | $0 |

Total Present Value of Alternative (rounded to the nearest $1,000)	| $5,737,000 |

Page 3 of 3

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APPENDIX E
DNREC CONCURRENCE LETTER

-------
DIRECTOR'S

Office

DEPARTMENT OF NATURAL RESOURCES AND
ENVIRONMENTAL CONTROL
Division of Waste and Hazardous Substances
Richardson & Robbins Building
89 Kings Highway
Dover, Delaware 19901

Phone
(302) 739-9400

January 12, 2024

Mr. Paul Leonard, Director

US EPA Region III
4 Penn Center
1600 JFK Blvd.

Philadelphia, PA 19103-2029

RE: State of Delaware Concurrence for Blades Groundwater

Operable Unit-2 (OlJ-2) (DE-1675) Record of Decision for Interim Action

Dear Mr. Leonard:

Thank you for the opportunity to review and comment on the United States
Environmental Protection Agency's ("US EPA") selected remedy and Record of Decision for
Interim Action for the Blades Groundwater Superfund OU-2 Site in Blades, Delaware. The State
of Delaware hereby concurs with the proposed remedy of Connection of Residents to the Public
Water Line for the Blades Groundwater Superfund Site Operable Unit 2.

Feel free to reach me at (302) 395-2600 if you have any questions or concerns about this
concurrence.

cc: Qazi Salahuddin, Environmental Program Administrator, DNREC-WHS-Remediation Section

Amy Bryson, Program Manager II, DNREC-WHS-Remediation Section
Rick Galloway, Project Manager, DNREC-WHS-Remediation Section

Sincerely.

Director

Division of Waste & Hazardous Substances

TTR:QS:slw
TTR22000-RS.docx
DE-1675 II B9

-------