United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R01 -91/060
September 1991
&EPA
Superfund
Record of Decision
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REPORT DOCUMENTATION 11. REPORTNO. I ~ 3. RecIpient'. ACC888Ion No.
PAGE EPA/ROD/R01-91/060
4. 1118II1II 8ubII8 5. Report D8te
SUPERFUND RECORD OF DECISION 09/23/91
Nyanza Chemical, MA
6.
Second Remedial Action
7. Aulhor(.) 8. Performing OrgenlDtion Rept. No.
8. Performing Org8lnlDtlon N8me end Add..... 10. ProjectlT88IIIWork Unit No.
11. ContnICI(C) or Gr8Rl(G) No.
(C)
(G)
1~ SponeorIng Orgenlzallon N8m8 end Addre88 13. Type of Report . PerIod Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. Suppl8m8nt8Jy No...
16. Ab81r8ct (LbNt: 2110 _rd8)
The 35-acre Nyanza Chemical site is a former dye manufacturing facility in Ashland,
Middlesex County, Massachusetts. Land adjacent to the site is used for industrial,
residential, commercial, and recreational purposes. Wetlands are located to the
north and east; woodlands lie to the south, southeast, and west; and the Sudbury
River is 700 feet north of the site. The site overlies an unconsolidated glacial
aquifer, which has been affected by site activities. The study area for this ground
water operable unit is larger than the site and consists of up to 395 acres. From
1917 to 1978, the property was occupied by several companies involved in
manufacturing textile dyes, dye intermediates, inorganic collodial solids and acrylic
polymers. Starting in 1917, several types of wastes were disposed of in various
onsite locations including Megunko Hill, an unsecured landfill/disposal area in the
southern portion of the site, and wetlands areas to the east and northwest. Wastes
included process wastewater, chemical sludge, solid process wastes in drums, solvent
recovery distillation residue in drums, off-specification products, and un-recyclable
process chemicals including phenol, nitrobenzene, and mercuric sulfate. The dye
waste stream and wastewater were discharged to an onsite concrete "vault" or settling
(See Attached Page)
17. DocI.m8nt An8Iy8I8 L DncrIptora
Record of Decision - Nyanza Chemical, MA
Second Remedial Action
Contaminated Medium: gw .
Key Contaminants: VOCs (benzene, PCE, TCE, toluene), other organics, metals
(arsenic, chromium, lead)
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EPA/ROD/ROl-91/060
Nyanza Chemical, MA
Second Remedial Action
Abstract (Continued)
c
basin adjacent to the main processing building. The liquid occasionally overflowed
through a pipe into the wetlands and to surface water. In the 1960's or 1970's, the
vault was removed from service, and subsequently was filled in with sludge and covered
over with fill. In 1970, a State investigation linked the site to mercury
contamination in the nearby Sudbury River. A 1985 Record of Decision (ROD) addressed
soil and wetland excavation at nine localized areas of contamination; solidification of
water-bearing excavated sludge, sediment, and soil; and placement, capping, and
consolidation of those materials left in place on Megunko Hill, as Operable Unit 1
(OU1). In addition, a diversion trench was constructed on the side of Megunko Hill to
divert surface water flow, and lower the ground water table around Megunko Hill. In
1985, the State constructed fencing along a road embankment, placed one foot of clean
fill over an area to prevent direct contact, and culverted surface water through a
neighboring property under an Interim Response Measure. In 1987, under an EPA removal
action, 655 tons of soil adjacent to the vault were removed; 309 tons were incinerated,
and 356 tons of soil were transported offsite to an approved landfill. In 1988, EPA
solidified onsite 2,000 tons of sludge from the vault and disposed of the sludge at an
offsite RCRA landfill facility. This ROD addresses management of migration as OU2, and
'constitutes an interim remedy designed to treat the highest ground water contamination
and to collect additional data achieving cleanup objectives. A subsequent ROD will
address uncontrolled wastewater discharges to the Sudbury River and its tributaries.
The primary contaminants of concern affecting the ground water are VOCs including
benzene, PCE, TCE, and toluene; other organics; and metals including arsenic, chromium,
and lead.
The selected interim remedial action for this site includes constructing extraction
wells at the northern border of the site; constructing a ground water treatment plant
that utilizes precipitation and filtration to remove inorganics, and ultraviolet
oxidation or biological treatment as well as carbon adsorption to remove organics,
pumping and treating ground water, with onsite discharge of treated water to surface
water; performing pump tests in the eastern portion of the plume to determine the need
for future ground water remediation; installing additional deep bedrock wells to fully
define depth and location of contamination; inspecting the Megunko Road water line;
monitoring ground water and surface water; and implementing institutional controls
including deed and ground water use restrictions, as well as site access restrictions.
The estimated present worth cost for this remedial action is $7,440,000, which includes
an estimated O&M cost of $2,160,000 over 5 years.
PERFORMANCE STANDARDS OR GOALS:
subsequent ROD.
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.-
DECLARATION FOR THE RECORD OF DECISION
r-
Nyanza Chemical Waste Dump, Operable unit II
Ashland, Massachusetts
statement of PurDose
This Decision Document presents the selected interim remedial
action for this site developed in accordance with the
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and to the extent
practicable, the National contingency Plan (NCP) , 40 CFR
Part 300, 55 Federal Register 8666 (March 8, 1990).
The Commonwealth of Massachusetts has concurred with the selected
remedy.
statement of Basis
This decision is based on the Administrative Record which was
developed in accordance with Section 113(k) of CERCLA and which
is available for public review at the information repositories
located at the Ashland Public Library in Ashland, Massachusetts,
and at the EPA offices at 90 Canal Street in Boston,
Massachusetts. The attached index identifies the items which
comprise the Administrative Record upon which the selection of a
remedial action is based.
Description of the Selected Remedv
In summary, the remedy provides for: 1) extracting contaminated
groundwater from the northern portion of the site near the
railroad tracks and industrial park, and optionally at the
southern border of the cap now under construction on Megunko Hill
for a minimum of 5 years; 2) treating the groundwater with a
combination of physical and chemical processes; 3) discharging
the treated water into the Sudbury River; 4) using institutional
and access controls to limit exposure to contaminants;
5) performing pump tests in the eastern portion of the plume to
help determine the feasibility of cleaning up groundwater in this
area at some future point; 6) installing additional deep bedrock
wells to more fully define the depths and locations to which
contaminants may have migrated; 7) performing continuing
monitoring of selected existing residential and monitoring wells
and limited surface water testing to track any further progress
-------
performing certain pre-design studies to aid in the design of the.
selected remedy.
The first operable unit addressed contaminated sludges and soils
by excavating them from outlying areas, and consolidating them
with sludges already on Megunko Hill under an impermeable cap.
The first operable unit ROD also included an upgradient diversion
trench to preclude contact with groundwater and surface water
runoff with the buried material. Construction of the first
operable unit remedy is expected to be completed in late 1991.
"
This second operable unit interim remedial action will serve to
collect data to refine the cleanup time estimates for the final
Record of Decision, and will in the interim address the following
principal threats to human health and the environment posed by
the site: migration of contaminants in groundwater, risks to
human health associated with potential future consumption and
direct contact with groundwater, risks from present and potential
future inhalation of evaporated groundwater contaminants, and
degradation of the Sudbury River and wetlands due to the natural
discharge of contaminated groundwater.
The third operable unit
uncontrolled wastewater
tributaries. A ROD for
year.
concerns the impact of Nyanza's past
discharges to the Sudbury River and its
that Operable Unit is scheduled for next
Declaration
The selected remedy is protective of human health and the
environment, attains Federal and State requirements that are
applicable for this remedial action and is cost-effective. The
selected remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent practicable. The
statutory preference for remedies that utilize treatment as a
principal element to reduce the mobility, toxicity, or volume of
hazardous substances is met by the selected remedy.
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o
IntroeSuction
This document is the index to the GrouneSwater stueSy, (Operable
Unit II) Administrative Record for the Nyanza Chemical Waste Dump
National Priorities List (NPL) site. section I of the index cites
site-specific documents, and Section II cites guidance documents
used by EPA staff in selecting a response action at the site. This
index contains confidential documents that are available only for
judicial review.
The Administrative Record is available for public review at
EPA Region I's Office in Boston, Massachusetts, and at the Ashland
Public Library, 66 Front Stree~, Ashland, Massachusetts, 01721.
Although not expressly listeeS in this ineSex, all eSocuments
containeeS in the administrative recoreS for the september 4, 1985,
Record of Decision (Opera~le Unit I) are incorporated ~y reference
herein, aneS are expressly made a part of the administrative record
for the present operable unit, Nyanza Chemical Waste Dump
GrouneSwater stueSy. Questions concerning the Administrative Record
should be addressed to the EPA Region I site manager.
The Administrative Record is required by the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA),
as amended by the Superfund Amendments and Reauthorization Act
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VOLUME I
2.0
3.0
VOLUME II
3.0
VOLUME III
3.0
-.
4.0
VOLUME IV
4.0
VOLUME V
Nyanza Chemical Waste Dump
(Groundwater Study)
NPL site Administrative Record
o
Table of Contents
Removal Response
o
2.1
2.5
2.9
Correspondence
On-Scene Coordinator Reports
Action Memoranda
Remedial Investigation (RI)
3.1
3.2
Correspondence
Sampling and Analysis Data
Remedial Investigation (RI) (continued)
3.4
3.6
Interim Deliverables
Remedial Investigation (RI) Report
Remedial Investigation (RI) (continued)
3.6
3.7
3.9
Remedial Investigation (RI) Report (continued)
Work Plans and Progress Reports
Health Assessments
Feasibility Study (FS)
. 4.1
Correspondence
Feasibility study (FS) (continued)
4.4
4.6
4.0
Interim Deliverables
Feasibility Study (FS) Report
Feasibility Study (FS). (continued)
4.6
4.9
Feasibility study (FS) Report (continued)
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Nyanza Chemical Waste Dump
(Groundwater study)
NPL site Administrative Record
Table of contents (continued)
VOLUME V (continued)
5.0
Record of Decision (ROD)
5.3
5.4
Responsiveness Summary
Record of Decision (ROD)
VOLUME VI
11.0 potentially Responsible Party (PRP)
11.9 PRP-specific Correspondence
13.0 community Relations
13.2 Community Relations plan
13.3 News Clippings/Press Releases
13.4 public Meetings
13.5 Fact Sheets
17.0 site Management Records
17.1 Correspondence
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SECTION I
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2.0
ADMINISTRATIVE RECORD INDEX
for the
Nyanza Chemical Waste Dump
(Groundwater Study)
Operable Unit II
2.1
Removal Response
Correspondence
1.
"Massachusetts Field Investigation Team Letter
Report - Nyanza Vault Site Ashland, Massachusetts
- Phase II Investigation," Wehran Engineering
(November 17, 1986).
Cross-Reference: Letter from Edward J. Conley,
EPA Region I to MCL Development Corporation (March
23, 1987). . concerning Potentially Responsible
Party status and the necessity of immediate
removal in connection with the Nyanza Hazardous
Waste Site. (Filed and cited as entry number 21
in section 11.9PRP-Specific Correspondence].
Cross-Reference: Letter from Edward J. Conley,
EPA Region I to Nyacol Products, Inc. (March 23,
1987). Concerning Potentially Responsible Party
status and the necessity of immediate removal in
connection with the Nyanza Hazardous Waste Site.
[Filed and cited as entry number 27 in section
11.9 PRP-Specific Correspondence].
Cross-Reference: Letter from Thomas J. Sartory,
Goulston & Storrs (Attorney for Nyacol Products,
Inc.) to Frank W. Lilley, EPA Region I (April 2,
1987). Concerning the scheduled meeting on April
3, 1987 to discuss proposed EPA actions arid the
impact of EPA's activities on production. (Filed
and cited as entry number 28 in section 11.9 PRP-
Specific Correspondence]. .
Memorandum from Bob Bois, and Madeline Snow,
Massachusetts Department of Environmental Quality
Engineering to Herb Redman (May 5, 1987).
Concerning vault removal at the Nyanza site. With
the attached, Internal Memorandum from Karen
Martin, Massachusetts Department of Environmental
Quality Engineering to Bob Bois (April 21, 1987).
Concerning the characterization of potential
health threat from the Nyanza site.
2.
3.
4.
5.
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3.0
2.1. correspondence (continued)
2.5
2.9
6.
Cross-Reference: Letter from J. Thomas Robinson,
Nyacol Products, Inc. to Frank W. Lilley, EPA
Region I (June 5, 1987). Concerning the impact of
the vault removal and EPA activity on employee
health and disruption of manufacturing operations.
[Filed and cited as entry number 29 in section
11.9 PRP-Specific Correspondence].
On-Scene Coordinator Report
1.
"After Action Report for Nyanza Vault Hazardous
Waste Site, Ashland, Massachusetts," WESTON-SPER
Technical Assistance Team Region I (July 1988).
(The Enforcement Section of the Memorandum is
withheld as CONFIDENTIAL).
Action Memoranda
1.
Internal Memorandum from Frank W. Lilley, EPA
Region I to Michael R. Deland (April 27, 1987). .
Concerning request to commence removal action at
Nyanza Waste site. (The Enforcement Section of
the Memorandum is Withheld as CONFIDENTIAL).
Remedial Investigation (RI)
3.1
Correspondence.
1.
Letter from Laura Miller, Ashland Resident to EPA
Region I (April 18, 1985). Concerningbasement
water seepage and odor.
Trip Report on a Visit to Nyanza Chemical Site, !
Martha Meyers Lee, NUS corporation (April 23,
1986). Concerning sampling of water in
residential basements (April 3, 1986) near the
Nyanza Chemical site.
Letter from Gillette Henry, Ashland Resident to
Richard Cavagnero, and Mary Sanderson, EPA Region
I (June 28, 1986). Concerning request for report
of wet basement samples taken by NUS Corporation.
2.
3.
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(continued)
3.1 .Correspondence
4.
Letter from Richard J. Chalpin, Massachusetts
Department of Environmental Quality Engineering to.
Beverly and Alden Dort, Ashland Residents
(February 9, 1987). Concerning analytical results
of basement samples taken on August 19, 1986.
With attached, "Memorandum for the Record,"
patricia Donahue, Massachusetts Department of
Environmental Quality Engineering (September 2,
1986). Concerning results of sampling at the Dort
residence. .
Letters from Mary C. Sanderson, EPA Region I to
Ashland residents, Mrs. Beverly Dort, Mrs. Eunice
Flood, Mrs. Gillette Henry, Mrs. Doris Merloni,
Mr. Thomas Regan, and Mr. and Mrs. Donald Weld,
(January 29, 1987). Concerning the attached,
"Technical Assistance: Residential sampling," NUS
corporation, detailing sampling conducted on April
3, 1986 and June 9, 1986, (January 26, 1987).
Memorandum from Bruce Marshall, EPA Region I to
Librarian, Ashland Public Library (January 27,
1988). Concerning the Field Operation Plan.
Memorandum from Bruce Marshall, EPA Region I to
Richard Brown, et al., Ashland Advocates for a
Clean Environment (AACE) and Tom Robinson, Nyanza
Community Advisory Committee (NCAC) (January 27,
1988). Concerning the Phase II RIfFS Field
operation Plan.
"Memorandum for the Record," patricia Donahue,
Massachusetts Department of Environmental Quality
Engineering (May 24, 1988). Concerning DEQE Case
No. 03-216, drinking water sampling.
Letter from Mark D. Semenuk, Ashland Water and
Sewer Department to Richard J. Chalpin,
Massachusetts Department of Environmental
Protection (July 17, 1989). Concerning water
mains on Megunko Road.
Letter from patricia Donahue, and Richard J.
Chalpin, Massachusetts Department of Environmental
Protection to Mark D. Semenuk, Ashland Water and
Sewer Department (August 1, 1989). Concerning
answers to water main concerns and request for
additional information.
5.
6.
7.
8.
9.
10.
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3.1 Correspondence
3.2
-.
*
(continued)
11.
Letter from Mark D. Semenuk, Ashland Water and
Sewer Department to Richard J. Chalpin,
Massachusetts Department of Environmental
Protection (August 16, 1989). Concerning
information requested. With attached:
A: "Leak Detection Survey Location--Megunco
Road," Mark D. Semenuk and Charlie
Philbrick, Ashland Water and Sewer
Commission (July 19, 1989).
Diagrams of Water Main on Megunco Road
(August 21, 1989).
C: Hydrant Flow Data Summary (June 1986).
Internal Memorandum from Peter R. Kahn, EPA Region
I to David Lederer (January 7, 1991). Concerning
the attached, "Indoor Air Screening Survey
Results," EPA Region I (December 1990).
B:
12.
Sampling and Analysis Data
1.
Memorandum from Martin E. Mortensen, EPA Region II
to Frank Lilley, EPA Region I (October 6, 1987).
Concerning report on well drilling, sampling
activities, hydrog~ology and the attached, "Well
Installation and Ground Water Sampling", ERB/REAC
for ERB/ERT (September 30, 1987).
Cross-Reference: "Indoor Air Screening Survey
. Results, Nyanza Chemical Superfund Site, Ashla~d,
Massachusetts," EPA Region I (December 1990).
[Filed and cited as entry number 12 in section 3.1
Correspondence).
"Analytical Results, Phase I Surface Water and
Sediment Sampling, Nyanza Operable Unit III -
Sudbury River Study, Middlesex County,
Massachusetts," with attached over~ized plates A
and B, NUS Corporation (May 1991). (Note:
Oversized plates may be reviewed by appointment
only at EPA Region I, Boston, Massachusetts).
2.
3.
Additional Sampling and Analysis Data may be .
reviewed by appointment only, at EPA Region I,
Boston, Massachusetts.
3.4
Interim Deliverables
1.
Internal Letter from J. Kevin Reilly, and David
Chin, EPA Region I to Mary Sanderson,EPA Region I
(December 16, 1986). Concerning the sanitary
report of the Ashland water system sent to the
State of Massachusetts.
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3.4 . Interim Deliverables
(continued)
3.6
3.7
2.
Letter from J. Kevin Reilly, and David Chin, EPA
Region I to Mr. Chester Mysel, Massachusetts
Department of Environmental Quality Engineering
(December 16, 1986). concerning recommendations
based on the October 28, 1986 sanitary survey
conducted on the Ashland water system.
"Final Field Operations Plan - Remedial
Investigation/Feasibility study, Nyanza Chemical
Site, Operable Unit II Groundwater Study," E.C.
Jordan Company for Ebasco Services Incorporated
(January 1988).
Letter from Luis Seijido, Ebasco Services
Incorporated to David Lederer, EPA Region I (June
13, 1990). concerning the. development of
treatment trains, other potentially applicable
technologies and the attached, "Treatability Study
Evaluation, Nyanza Chemical Site, Operable Unit
II, AshlandJ Massachusetts," SEA Consultants, Inc.
for Ebasco Services Incorporated (June 1990).
3.
4.
Remedial Investigation (RI) Report
1.
"Draft Final Remedial Investigation Report, Nyanza
II Groundwater Study, Ashland, MA," (Volume I-II)
Ebasco Services Incorporated (April 1991).
(Note: Volume I contains an oversized map that
may be reviewed, by appointment only at EPA Region
I, Boston, Massachusetts.)
Work Plans and Progress Reports
1.
Cross-Reference: Trip Report on a Visit to Nyanza
Chemical Site, Martha Meyers Lee, NUS Corporation
(April 23, 1986). Concerning sampling of water in
residential basements (April 3, 1986) near the
Nyanza Chemical site. [Filed and cited as entry
number 2 in section 3.1 Correspondence].
"Data Quality Objectives (DQO) Information
Document, Nyanza 11- Groundwater Study, Ashland,
Massachusetts," E.C. Jordan Co. for Ebasco
Services Incorporated (August 1987).
"Final Work Plan, Nyanza II - Groundwater Study,
Ashland, Massachusetts," E.C. Jordan Company for
Ebasco Services Incorporated (December 1987).
2.
3.
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4.0
3.9
Health Assessments
1.
Letter from Richard Brown and Maureen Lavin,
Nyanza Citizen Advisory Committee to Mary
Sanderson, EPA Region I (December 11, 1986).
Concerning the Nyanza Citizen Advisory Committee
petition to conduct a health study.
Memorandum from Marilyn R. DiSirio, Agency for
Toxic Substances and Disease Registry to Mary
Sanderson, EPA Region I (March 16, 1987).
Concerning citizen's petition for a health study
at the Nyanza site.
Letter from Bruce Marshall, EPA Region I to
Maureen Lavin, Nyanza Citizen Community Advisory
Committee (October 30, 1987). Concerning informal
procedures for requesting a health assessment.
2.
3.
4.1
Feasibility Study (FS)
Correspondence
4.4
4.
5.
1.
2.
Internal memorandum from
to David Lederer (May 7,
of contamination in deep
of remediation.
Internal memorandum from Al Klinger, EPA Region I
to David Lederer (May 17, 1991) . Concerning the
need for downgradient bedrock monitoring at
Nyanza.
Letter from Donna Grotzinger, Ebasco Services
Incorporated to David Lederer, EPA Region I (June
12, 1991). Concerning cost estimates in support
of the Nyanza Groundwater Proposed Plan.
Letter from Henry M. Fassler, Ashland Board of
Health to David Lederer, EPA Region I (June 14,
1991). Concerning transmittal of attached list of
private wells within the Town of Ashland.
Letter from Donna Grotzinger, Ebasco Services
Incorporated to. David Lederer, EPA Region.I (June
20, 1991). Concerning transmittal of the Town of
Ashland private well water distribution map.
Al Klinger, EPA Region I
1991)~ Concerning extent
bedrock, and po~sibility
3.
1.
Interim Deliverables
"Draft Final Risk Assessment Report, Nyanza
Chemical Waste Dump Site, Operable Unit II -
Groundwater Study, Ashland, MA," Ebasco Services
Incorporated (June 1991).
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5.0
4.6
4.9
Feasibility Study
1.
Cross-reference: Letter from Luis Seijido, Ebasco
Services Incorporated to David Lederer, EPA Region
I (June 13, 1990). Concerning the development of
treatment trains, other potentially applicable
technologies and the attached, "Treatability Study
Evaluation, Nyanza Chemical Site, Operable Unit
II, Ashland, Massachusetts," SEA Consultants, Inc.
for Ebasco Services Incorporated (June 1990).
[Filed and cited as entry number 4 in section 3.4
Interim Deliverables]. 0
"Draft Final Feasibility study Report, Nyanza
Chemical Waste Dump Site, Operable Unit II -
Groundwater study, Ashland, MA," Vol I and II,
Ebasco Services Incorporated (June 1991).
2.
Comments on the Feasibility study received by EPA
Region I are summarized in the Responsiveness
Summary, which is Appendix I of the Record of
Decision (ROD). The ROD is filed and cited as
entry number 1 in 5.4 Record of Decision (ROD).
Proposed Plans for Selected Remedial Action
*
1.
"EPA Proposes Cleanup Plan for the Nyanza Chemical
Waste Dump Site," Ebasco Services Incorporated,
with attached list of addressees (June 1991).
Record of Decision (ROD)
5.3
Responsiveness Summaries
1.
Cross-Reference: Responsiveness Summary is in
Appendix I of the Record of Decision [Filed and.
cited as entry number 1 in 5.4 Record of Decision
(ROD) ] .
5.4
Record of Decision (ROD)
01.
"Record of Decision: Nyanza Chemical Waste Dump
site, Groundwater Study, Operable Unit II," EPA
Region I (September 23, 1991).
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11.0 Potentially Responsible Party (PRP)
11.9 PRP-Specific Correspondence
AIF REALTY TRUST
1. Letter from Merrill S. Hohman, EPA Region I to AIF
Realty Trust (June 21, 1991). Concerning Notice
of Potential Liability at Nyanza Chemical Waste
Dump with attached list of Potentially Responsible
Parties.
ASHLAND REALTY
2.
3.
DEVELOPMENT CORPORATION
Letter from Merrill S. Hohman, EPA Region I to
Ashland Realty Development Corporation (January
22, 1991). Concerning Notice of Potential
Liability at Nyanza Chemical Waste Dump with
attached list of Potentially Responsible Parties.
Letter from Merrill S. Hohman, EPA Region I to
Robert E. Gayner, Ashland Realty Development
Corporation (February 11, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
JOHN P. BAUM
4.
Letter from Merrill S. Hohman, EPA Region I to
John P. Baum (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
EDWARD B.
BELL, JR.
5. Letter from Merrill S. Hohman, EPA Region I to
Edward B. Bell, Jr. (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
J. BELMAR, INCORPORATED
6. Letter from Merrill S. Hohman, EPA Region I to J.
Belmar, Incorporated (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties. .
BERNARD AND PAULINE BLOOMSTEIN
7. Letter from Merrill S. Hohman, EPA Region I
Bernard and Pauline Bloomstein (January 22,
Concerning Notice of Potential Liability at
Chemical Waste Dump with attached list of
Potentially Responsible Parties.
Letter from Merrill. S. Hohman, EPA Region I to
Bernard and Pauline Bloomstein (July 22, 1991).
Concerning notification of removal from list of
potentially responsible parties.
to
1991) .
Nyanza
8.
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11.9 'PRP-Specific Correspondence (continued)
EDWARD J.
CAMILLE
9. Letter from Merrill S. Hohman, EPA Region I to
Edward J. Camille (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
SAMUEL CAPLIN
10.
11.
Letter from Merrill S. Hohman, EPA Regio~ I to
Samuel caplin (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties~
Letter from Merrill,S. Hohman, EPA Region I to
Samuel Caplin (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
'CONSOLIDATED RAIL CORPORATION
12. Letter from Merrill S. Hohman, EPA Region I to
J.C. Curry, Consolidated Rail Corporation (January
22, 1991). Concerning Notice of Potential
Liability at NyanzaChemical Waste Dump with
attached list of Potentially Responsible Parties.
ESTATE OF
ROLAND E. bERBY, JR.
13. 'Letter from Merrill S. Hohman, EPA Region I to
Middlesex County Probate Court (January 22, 1991).
Concerning Notice of Potential Liability which the
Estate of Roland E. Derby, Jr. (Docket No. 507540)
has or may have at the Nyanza Chemical Waste Dump
with attached list of Potentially Responsible
Parties.
ESTATE OF
ROLAND E. DERBY, SR.
14. Letter from Merrill S. Hohman, EPA Region I to
Middlesex County Probate Court (January 22,
1991). Concerning Notice of Potential Liability
which the Estate of Roland E. Derby, Sr. (Docket
No. 412228) has or may have at the Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
ENVIRONMENTAL
15.
RESTORATION ENGINEERING TRUST
Letter from Merrill S. Hohman, EPA Region I to
John J. Glynn, Jr., Environmental Restoration
Engineering Trust (January 22, 1991). concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
-------
11.9 PRP-specific correspondence (continued)
ROBERT E.
GAYNER
16. Letter from Merrill s. Hohman, EPA Region I to
Robert E. Gayner, Black Point, Derby Side
(February 11, 1991). Concerning Notice of
Potential Liability at Nyanza Chemical Waste Dump
with attached list of Potentially Responsible
Parties.
MARTHA E.
AND NELSON HOLDEN
17. Letter from Merrill S. Hohman, EPA Region I to
Martha E. and Nelson Holden, Holden - Ashland
Trust (January 22, 1991). concerning Notice of
Potential Liability at Nya~za Chemical Waste Dump
with attached list of Potentially Responsible
Parties.
WILLIAM
M. LEACU
18. Letter from Merrill S. Hohman, EPA Region I to
william M. Leacu (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
DR. ROBERT LURIE
19. Letter from Merrill S. Hohman, EPA Region I to Dr.
Robert Lurie (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
EDWARD M.
LYNCH, JR.
20. Letter from Merrill S. Hohman, EPA Region I to
Edward M. Lynch, Jr. (July 22, 1991). concerning
notification of removal from list of potentially
responsible parties.
...
MCL DEVELOPMENT CORPORATION
. 21. Letter from EdwardJ. Conley, EPA Region I to MCL
Development Corporation (March 23, 1987).
Concerning Potentially Responsible Party status
and the necessity of immediate removal in
connection with the Nyanza Hazardous Waste Site.
22. Letter from William F. Hicks, Cuddy, Lynch, Manzi
& Cunningham, P.C. (Attorney for MCL Development
corporation) to Frank W. Lilley, EPA Region I
(March 31, 1987). Concerning tentative agreement
to meet .on April 3, 1987 to discuss removal
actions.
-------
11.9 PRP-Specific Correspondence (continued)
MCL DEVELOPMENT CORPORATION (continued)
23. Letter from Merrill S. Hohman, EPA Region I to MCL
Development Corporation (January 22, 1991).
Concerning Notice of Potential Liability at Nyanza
Chemical Waste Dump with attached list of
Potentially Responsible Parties.
24. Letter from Merrill S. Hohman, EPA Region I to
Robert E. Gayner, MCL Development corporation
(February 11, 1991). Concerning Notice of
Potential Liability at Nyanza Chemical Waste Dump
with attached list of Potentially Responsible
Parties.
MEGUNKO -
NYACOL
CHERRY REALTY TRUST
25. Letter from Merrill S. Hohman, EPA Region I to
Frances A. and Peter A. Bruen, Megunko - Cherry
Realty Trust (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
26. Letter from Merrill S. Hohman,EPA Region I to
Frances A. and Peter A. Bruen, Megunko ~ Cherry
Realty Trust (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
PRODUCTS, INC.
.27. Letter from Edward J. Conley, EPA Region I to
Nyacol Products, Inc. (March 23, 1987).
Concerning Potentially Responsible Party status
and the necessity of immediate removal in
connection with the Nyanza Hazardous Waste Site.
28. Letter from Thomas J. Sartory, Goulston & storrs
(Attorney for Nyacol Products, Inc.) to Frank W.
Lilley, EPA Region I (April 2, 1987). Concerning
the scheduled meeting on April 3, 1987 to discuss
proposed EPA actions and the impact of EPA~s
activities on production.
29. Letter from J. Thomas Robinson, Nyacol Products,
Inc. to Frank W. Lilley, EPA Region I (June 5,
1987). Concerning the impact of the vault removal
and EPA activity on employee health and disruption
of manufacturing operations.
30. Letter from Merrill S. Hohman, EPA Region I to J.
Thomas Robinson, Nyacol Products, Inc. (January
22, 1991). Concerning Notice of Potential
Liability at Nyanza Chemical Waste Dump with
attached list of Potentially Responsible Parties.
-------
11.9 PRP-Specific Correspondence (continued)
NYANZA, 'INC.
31.
Letter from Merrill S. Hohman, EPA Region I to
Scott D. Taylor, Nyanza, Inc. (January 22, 1991).
concerning Notice of Potential Liability at Nyanza
Chemical Waste Dump with attached list of
Potentially Responsible Parties.
DR. THOMAS O'CONNOR
32. Letter from Merrill S. Hohman, EPA Region I to Dr.
Thomas O'Connor (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
EARL A. PIKE,
33.
JR.
Letter from Merrill S. Hohman, EPA Region I to
Earl A. Pike, Jr. (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
PQ CORPORATION
34.
Letter from Merrill S. Hohman, EPA Region I to
Ernest G. Posner, PQ Corporation (January 22,
1991). concerning Notice of Potential Liability
at Nyanza Chemical Waste Dump with attached list
of Potentially Responsible Parties.
PYNE SAND
& STONE COMPANY
35. Letter from Merrill S. Hohman, EPA Region I to
James G. pyne, pyne Sand & Stone Company, Inc.
(January 22, 1991). Concerning Notice of
Potential Liability at Nyanza Chemical Waste Dump
with attached list of Potentially Responsible
Parties.
36. Letter from Merrill S. Hohman, EPA Region I to
James G. pyne, pyne Sand & Stone Company, Inc.
(July 22, 1991). concerning notification of
removal from list of potentially responsible
parties.
ROHM
TECH, INC.
37. .Letter from Merrill S. Hohman, EPA Region I to
Ekkehard Grampp, Rohm Tech, Inc. (January 22,
1991). concerning Notice of Potential Liability
at Nyanza Chemical Waste Dump with attached list
of Potentially Responsible Parties.
-------
11.9 PRP-Specific Correspondence (continued)
SHOESMITH
38. Letter from Merrill S. Hohman, EPA Region I to
Thomas W. Shoesmith (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
THOMAS W.
SPICER
39. Letter from Merrill S. Hohman, EPA Region I to
George W. spicer (July 22, 1991). Concerning
notification of removal from list of potentially
responsible parties.
GEORGE W.
TAYLOR .
40. Letter from Merrill S. Hohman, EPA Region I to
Scott D. Taylor (January 22, 1991). Concerning
Notice of Potential Liability at Nyanza Chemical
Waste Dump with attached list of Potentially
Responsible Parties.
SCOTT D.
13.0 Community Relations
13.2 Community Relations Plan
Letter from Sanford M. Matathia, Rackemann, Sawyer
& Brewster (Attorney for Ashland Board of Health)
to Maureen Lavin, Chairman Ashland Board of Health
(February 26, 1986). Concerning the Draft
community Relations Plan.
"Community Relations Plan, Nyanza Chemical Site,
Ashland, MA" with attached Community Relations
Plan mailing list (February 1986).
13.3 News Clippings/Press Releases
1.
2 .
1-
~ .
"Environmental News," EPA Region I (May 1, 1987).
"Media Advisory," EPA Region I (September 25,
1987) .
"Environmental News - Residents Encouraged to
Attend Nyanza Discussion at Ashland Town Hall,"
EPA Region I (July 14, 1989).
"EPA Proposes Interim Groundwater Cleanup Plan for
the Nyanza Chemical Waste Dump Superfund Site,"
EPA Region I (June 14, 1991).
3.
4 .
-------
13.3 News Clippings/Press Releases (continued)
5.
"The United states Environmental Protection Agency
Invites Public Comment on the Feasibility study
and Proposed Plan for the Nyanza Chemical Waste
Dump Site Groundwater Study in Ashland,
Massachusetts and Announces the Availability of
the Site Administrative Record," Middlesex News
(June 21, 1991).
13.4 Public Meetings
1.
Notice of Public Meeting, including Agenda, to be
held on January 18, 1990, EPA Region I (January 8,
1990) .
Cross-Reference: Transcript, Proposed Cleanup
Plan Public Meeting for the Nyanza Chemical Waste
Dump Site (July 18, 1991) is in Appendix I of the
Record of Decision [Filed and cited as entry
number 1 in 5.4 Record of Decision (ROD)].
2.
13.5 Fact Sheets
1.
"Superfund Program Information Update - EPA To
Begin Ground-Water Study," EPA Region I (January
1988) .
"Superfund Program Fact Sheet - EPACompletes
Design of Hazardous Waste Containment System,
'Construction to Begin this Summer," EPA Region I
(March 1988).
"Information Update - Nyanza Chemical Superfund
Site, Ashland, Massachusetts," EPA Region I, with
additional information' about Nyanza Night IV
(public meeting) (May 1989).
2.
3.
17.0 Site Management Records
17.1 Correspondence
1.
Letter from Daniel Greenbaum, Massachusetts
Department of Environmental Protection to Julie
Belaga, EPA Region I (September 23, 1991).
concerning state concurrence with the selected
remedy.
-------
17.8. State and Local Technical Records
1.
Cross-Reference: "Massachusetts Field
Investigation Team Letter Report - Nyanza Vault
Site Ashland, Massachusetts - Phase II
Investigation," Wehran Engineering Consulting
Engineers (November 17, 1986). [Filed and cited
as entry number 1 in section 2.1 Removal Response
Correspondence].
Letter from William A. Brutsch, Massachusetts
Water Resources Authority to David Lederer, EPA
Region I (March 11, 1991). Concerning the
potential use of the Framingham Reservoirs, with
the attached:
A: Excerpts from the "Sudbury Reservoir
Water Treatment Plant, Southborough,
Massachusetts, Draft Environmental Impact
Report," Commonwealth of Massachusetts
Metropolitan District Commission Water
Division (1984).
B: Ex~erpts from the "Draft Drought
Management Plan,~ Massachusetts Water
Resources Authority and Commonwealth of
Massachusetts Metropolitan District'
Commission (1989).
C: Excerpts from the "Supplementary Drought
Contingency Plan," Massachusetts Water
Resources Authority and Commonwealth of
Massachusetts, Metropolitan District
Commission (1989) via transmittal letter from
William A. Brutsch, Massachusetts Water
Resources Authority and Joseph McGinn,
Metropolitan District Commission (July 17,
1989) .
D: Excerpts from the "Massachusetts Water
Resources Authority, MDC - MWRA Long Range
Water Supply Study and Environmental Impact
Report - 2020, Phase II Report,"
Massachusetts Water Resources Authority
(October 1990).
2.
-------
SECTION II
GUIDANCE DOCUKENTS
-------
GUIDANCE DOCUMENTS
EPA Guidance Documents may be reviewed at EPA Region I, Boston,
Massachusetts.
General Guidance Documents
1.
2.
3.
4.
Comprehensive Environmental Response. Compensation. and
Liabi1itv Act of 1980, amended October 17, 1986.
Memorandum from J. Winston Porter, HQ EPA to Addressees
("Regional Administrators, Regions I-X et ~1.), (OSWER
Directive 9234.0-05), July 9, 1987 (discussing interim
guidance on compliance with applicable or relevant and
appropriate requirements).
Memorandum from Jonathan Z. Cannon, HQ EPA to Addressees
("Waste Management Division Directors, Regions I, et al.,
October 18, 1989 (discussing considerations in Ground Water
Remediation at Superfund Sites with attached: U.S.
Environmental Protection Agency. Office of Environmental
and Remedial Response. Evaluation of Ground-Water
Extraction Remedies. Volume 1. Summary Report (EPA/540/2-
89/054), September 1989.)
"National oil and Hazardous Substances Pollution contingency
Plan," (40 CFR Part 300), March 8, 1990.
5.
U.S. Department of Health and Human Services.' National
Institute for occupational Safety and Health, and
occupational Safety and Health Administration. Occupational
Safety and Health Guidance Manual for Hazardous Waste site
Activities, October 1985.
6.
U.S. Environmental Protection Agency. Office of Emergency
and Remedial Response. Community Relations in Superfund:
HandbookClnterim Version) (EPA/HW-6, OSWER Directive
9230.0-3B), June 1988.
A
7.
U.S. Environmental Protection Agency.
and Remedial Response. Compendium of
operations Methods (EPA/540/P-87/001,
9355.0-14), December 1987.
Office of Emergency
Superfund Field
OSWER Directive
8.
U.S. Environmental Protection Agency. Office of Emergency
and Remedial Response. Guidance on Remedial Actions for
contaminated Groundwater at Superfund sites (OSWER Directive
9283.1-2), December 1988.
9.
U.S. Environmental Protection Agency. Office of Emergency
and Remedial Response. Superfund Federal-Lead Remedial
proiect Manaaement Handbook (EPA/540/G-87/001, OSWER
-------
14.
15.
16.
17.
18.
19.
Directive 9355.1-1), December 1986.
10.
u.s. Environmental Protection Agency. Office of Emergency
and Remedial Response. SUDer fund State-Lead Remedial
Proiect Manaaement Handbook (EPA/540/G-87/002), December.
1986.
11.
u.s. Environmental Protection Agency. Office of Emergency
and Remedial Response. SUDer fund Public Health Evaluation
Manual (OSWER Directive 9285.4-01), October 1986.
12.
u.s. Environmental Protection Agency. Office of Emergency
and Remedial Response. Handbook of Remedial Action at Waste
DisDosal Sites (EPA/625/6-85/006), October 1985.
U.S. Environmental Protection Agency. Office of Emergency
and Remedial Response. Guidance for Conductina Remedial
Investiaations and Feasibilitv Studies under CERCLA
(ComDrehensive Environmental ReSDonse. ComDensation. and
Liability Act), (EPA/540/G-89/004), October 1988.
13.
u.s. Environmental Protection Agency. Office of Health
Environmental Assessment. A ComDendium of Technoloaies
in the Treatment of Hazardous Waste (EPA/625/8-87/014),
September 1987. .
and
Used
u.s. Environmental Protection Agency. Office of Research
and Development. Hazardous Waste Engineering Research
Laboratory. Technoloay Briefs: Data Reauirements for
Selectina Remedial Action Technology (EPA/600/2-87/001),
January 1987.
u.s. Environmental Protection Agency. Office of Research
and Development. Hazardous Waste Engineering Research
Laboratory. Treatment Technoloay Briefs: Alternatives to
Hazardous Waste Landfills (EPA/600/8-86/017), July 1986.
u.s. Environmental Protection Agency. Office of Research
and Development. Hazardous Waste Engineering Research.
Laboratory. Handbook: Remedial Action at Waste DisDosal
Sites (Revised) (EPA/625/6-85/006), October 1985.
u.s. Environmental Protection Agency. Office of Solid
and Emergency Response. Data Ouality Obiectives for
Remedial ReSDonse Activities: DeveloDment Process
(EPA/540/G-87/003), March 1987.
Waste
u.s. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Interim Guidance on SUDer fund
Selection of RemedY (OSWER Directive 9355.0-19), December
-------
20.
24, 1986.
U.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Draft Guidance on CERCLA ComDliance
with Other Laws Manual (OSWER Directive 9234.1-01), August
8, 1988.
21.
. U.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Alternate Concentration Limits
Guidance (OSWER Directive 9481.00-6C, EPA/530-SW-87-017),
July 1987.
22.
U.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response and Office of Emergency and Remedial
Response. Mobile Treatment Technoloaies for SUDer fund
Wastes (EPA 540/2-86/003F), September 1986.
23.
U.S. Environmental Protection Agency. Region I Risk
Assessment Work Group. SUDDlemental Risk Assessment
Guidance for the SUDer fund Proaram (EPA 901/5-89-001),
1989.
June.
-------
RECORD OP DBCISION: HYAHZA CBBKICAL WASTB DUMP SITB
GROmmnTBR STUDY, OPBRABLE UHIT II
-------
L
Contents
II.
III.
IV.
VI.
VII.
VIII.
I.
V.
NYANZA CHEMICAL WASTE DUMP SITE
TABLE OF CONTENTS
Paqe Number
LIST OF TABLES. . . . . . . . . .
. . iv
LIST OF PIGURES
.........
. . v
.........
LIST OF PLATES. . . . . . . .
. . vi
. . . . . .
. . . . .
SITE NAME, LOCATION AND DESCRIPTION
. . . . . .
. 1-1
SITE HISTORY' ENFORCEMENT ACTIVITIES.
. . . . . . .
. 2-1
A.
B.
Land Use' Response History ~ . . .
Enforcement History. . . . . . . .
. . 2-1
. . . . . . . . 2-3
COMMUNITY PARTICIPATION
.........
. 3-1
. . 0 . . .
SCOPE' ROLE OF OPERABLE UNIT OR RESPONSE ACTION
. . . 4-1
SUMMARY OF SITE CHARACTERISTICS. . .
.......
. . 5-1
A.
B.
C.
D.
E.
General . . . . . . . . . . . . . . . . . . . 5-1
Topoqraphy . . . . . . . . . . . . . . . . . . 5-2
Geoloqy . . . . . . . . . . . . . . . . . . . . . . 5-3
Hydroqeology . . . . . . . . . . . . . . . . . 5-3
Contamination of Effected Media. . . . . . . . . . 5-4
SUMMARY OF SITE RISKS.
.......
. 6-1
. . . . .
A.
B.
C.
D.
E.
Groundwater Exposure Scenarios. . . . . . . . 6-2
Risk Characterizati~n . . . . . . . . . . . . 6-3
Uncertainties in Estimating Risk. 6-5
Ecological Assessment. . . . . . . . . . . . . . . 6-6
Conclusion. . . . . . . .. . . . . . . . . . . . . .6-6
DEVELOPMENT AND 'SCREENING OF ALTERNATIVES. .
. . . .
. 7-1
A.
B.
Statutory Requirements/Response Objectives. . . . 7-1
Technology and Alternative Development
and Screening. . . . . . . . . . . . . . . . . . . 7-1
DESCRIPTION OF ALTERNATIVES
. . . .
. 8-1
.........
-------
IX.
XI.
XII.
XIII.
...
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES. . 9-1
x.
THE SELECTED REMEDY. . . . . . . .
. 10-1
. . . . . .
A. Cleanup Levels. . . . . . . .. . . . . . . . . .
B. Description of the Remedial components. . . . .
. 10-2
. 10-2
STATUTORY DETERMINATIONS
. 11-1
. . .
. . . . .
A.
The Selected Remedy is protective of Human
Health and the Environment. . . . . . . . . . . . 11-1
The Selected Remedy Attains ARARs . . . . . . . . . 11-1
The Selected Remedial Action ia Coat Bffective . . 11-5
The Selected Remedy utilizes Permanent SOlutions
and Alternative Treatment or Resource Recovery
Technoloqies to the Maximum Extent Practicable. . 11-6
The Selected Remedy satisfies the Preference
for Treatment as a principal Blement . . . . . . . 11-6
B.
C.
D.
E.
DOCUMENTATION OP SIGNIFICANT CHANGES
. 12-1
. . .
. . . 8..
STATE ROLE
. 13-1
..............
. . .
. . . .
APPENDICES
Appendix
Appendix
Appendix
I----Responsiveness summary
II---State Concurrence Letter
III--Estimated Groundwater Concentrations
from 1988 and 1990 data
derived
-------
Table 6-1:
Table 6-2:
Table 6-3:
Table 6-4:
Table 6-5a:
Table 6-5b:
Table 6-6:
Table 6-7:
Table 6-8:
Table 6-9:
Table 7-1:
Table 11-1:
Table 11-2:
Table 11-3:
Table 11-4:
LIST OF TAELES
Summary of Conta~inants ~f Concern Selected for
the Nyanza Site Groundwater Operable Unit, 1988
and 1990
Exposure Pathways
Oral, Dermal, and Inhalation Exposure to
Groundwater as a Potable Drinking Water Supply
Exposure to Groundwater from Basement Seepage
Exposure Point Concentrations for Groundwater in
Basement Seepage, Downgradient Overburden Wells
1988 Groundwater Study
Exposure Point Concentrations for Groundwater in
Basement Seepage, Downgradient Overburden Wells
1990 Groundwater Study
Oral and Dermal Exposure to Surface Water at
Trolley Brook and Eastern Wetland, Nyanza II
Groundwater Study, Ashland Massachusetts
Summary Statistics for Selected Surface Water
Samples All Locations: Trolley Brook and Eastern Wetland,
Nyanza 11-1988 Groundwater Study, Ashland Massachusetts
Total Carcinogenic Risk for Downgradient Areas for
All Fathways, Nyanza II Groundwater Study,
Ashland, Massachusetts
Total Non-Carcinogenic Risk for Downgradient Areas
for All Pathways, Nyanza II Groundwater Study,
Ashland, Massachusetts
Nyanza Groundwater Remedial Alternatives
Chemical Specific ARARs
Location Specific ARARs
Action Specific ARARs
Influent Concentrations and Effluent Standards to Meet Water
Quality Criter.ia
-------
Figure 1-1:
Figure 1-2:
Figure 5-1:
Figure 5-2:
Figure 5-3:
Figure 5-4:
Figure 5-5:
Figure 5-6:
Figure 5-7:
Figure 5-8:
Figure 5-9:
Figure 5-10:
Figure 10-1:
Figure 10-2:
LIST OF FIGURES
Nyanza Operable Unit II Study Area
Nyanza Chemical Waste Dump Site Location
Bedrock Contour Map
Overburden Groundwater Contours
Overburden Aniline Concentration Contours
Bedrock Aniline Concentration Contours
Overburden Nitrobenzene Concentration Contours
Bedrock Nitrobenzene Concentration Contours
Overburden Dichlorobenzene Concentration Contours
Bedrock Dichlorobenzene Concentration Contours
Overburden Trichloroethene Concentration Contours
Bedrock Trichloroethene Concentration Contours
Location of Groundwater Extraction Wells and
Treatment Area for Selected Alternative
Gro~ndwater Extraction and Representative
Treatment Syste!':1
-------
LIST OF PLATES
Plate 1:
Base Map; Nyanza Groundwa~er study, Nyanza Chemical
Site
-------
I.
SITE NAME, LOCATION AND DESCRIPTION
The Nyanza Chemical Waste Dump Superfund Site - Groundwater study area is
located in the 'Town of Ashland, Middlesex County, Massachusetts (see Figure
1-1). Ashland is located in the Metrowest area of eastern Massachusetts,
bordered by Sherborn to the east, Southborough to the west and northwest,
Framingham to the north, and Hopkinton and Holliston to the south. Ashlana
is 25 miles west-southwest of Boston, and 20 miles east-southeast of
Worcester.
The "Site", for purposes of describing the Operable unit II - Groundwater
Study, consists of all areas in and adjacent to the Nyanza property which
appear to be sources of groundwater contamination.' The "Nyanza
property", which is a part of the Site, consists of approximately 35 acres
formerly owned by Nyanza, Inc. (Figure 1-2) and includes several wetlands,
the Megunko Hill area, and the lower industrial area along Megunko Road.
The Hill is located in the southern part of the property and was formerly
used as a landfill/disposal area. This area is currently the focus of
Operable Unit I remediation activities. The lower industrial area was
formerly the location of dye manufacturing facilities, the wastewater
treatment system and a series of settling lagoons south of Megunko Road.
The areal extent of the Site is approximately bounded by an active Conrail
railroad line and Chemical Brook to the north, wetland areas and Cherry
Street to the east, and undeveloped mixed hardwood forest land to the
south, southeast, and west. The Sudbury River is approximately 700 feet
north of the Site.
The "study area" of the Operable Unit II - Groundwater Study-is larger
the site. It consists of the Site plus the areal extent of wells
(approximately 3~5 acres) installed off the Nyanza property thus far.
This report also discusses the downgradient area, which is the area north
and east of the Site bounded by the Sudbury River. Groundwater
contamination'as a result of contaminant migration from the Nyanza site has
been documented in this area.
than
The Town of Ashland occupies approximately 12.9 square miles, of which 18
percent is open water and wetland areas, and more than 40 percent is
intensively developed. The bulk of development has occurred in response to
the need for single- and multiple-family housing created by rapid economic
expansion along the major transportation routes: State Route 128 (1-95),
1-495, U.S. Route 9, and 1-290. From 1951 to 1980, agriculture and open-
land use in the area has decreased 'from 19 to less than five percent.
The Site is classified as industrial, wetland, and forest (U.S. Department
of Forestry and Wildlife Management, 1982). South and southeast of the
Site, the upper elevations of Megunko Hill are forested with stands of
For purposes of CERCLA ~ 121(e) (1) in so far as it
relates to permits, "on-site" shall be "the areal extent of
contamination and all suitable areas in very close proximity to
the contamination necessary for implementation of the response
actions". National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), ~o CFR ~ 300.400(e). '
-------
r):::~l '''2, '\.-? .....~
}l--JI-,,) t.~')~
-(-v-~~II/( / ~
I \ ~.~
LOCATION MAP "\ j
-------
N
SfDIMENTATION
BASIN
MEGUNKO Hill
AREA
,
65"
D
~~
c:?
STREET
PLEASANT
~ tn
R~llROAD t; ~ ~ ~
-f f . -, - ~ 0
. -f.fl I ,~- 'If IL
\ oJ - -~ 'l~u'..-k..I. -
....,..' - -. " - ~ '. . ' '.--,."., + f
,... , I ---...~~.~ .~-t~+-f.-f
. '- C"£MIC~':-"
FORMER VAULT h T IJI/(XJI(
.,
,
'~"~"
~ ~
~""
FIlOl-lr' . ~,',~
~~REE:r ~'~.
=:::::::::--
WESTERN WETlAND
~.'--,
-: '.9--~ f~-f.~
~j
SURFACE WATER DRAIN
~ -- -- - OADWAY AROUND CAP
~
GROUND WATER
AND SURFACE WATER
DIVERSION TRENCH
LEGEND
FIGURE 1-2
Ed WETlANOS
t==3 BROOKS/STREAMS
NVANZA WASTE DUMP
SITE LOCATION.
NOT TO SCALE
SHEFf 1 OF 1
-------
~ixed hardwcQcs on well-drained, stc~y S2llS. ~~e lQwer industrial area of
the Site, built on udorth2~t soils (fil~ej ~r h~~=~-in:luen=ed land),
s~pports several light i~j~s~rie3 ani ==~~e~c:=: b~3i~=sses and little ~o
no vegetat~on..
The land north, northeast, and east of the Site is classified as urban-
suburban (U.S. Department of Forestry and wildlife Management, 1982). It
receives heavy use and includes residential, commercial, industrial, and
public recreation areas. The center of Ashland village is located less
than one-half mile northeast of Nyanza. Stone Park (the town park) is
located 1700 feet southeast of the Site and is heavily used during the
summer months. Ashland Junior High School is located just over three
quarters of a mile northwest of the Site. Much of the woodlands north of
the Sudbury River have been recently cleared for residential construction.
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II.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
A.
Land Use and Response History
From 1917 through 1978, the property was occupied by several companies
involved in manufacturing of several products. Textile dyes and dye
intermediates were produced on the Site until 1978 when Nyanza, Inc.
apparently ceased operations. Products manufactured on the property in
addition to those previously mentioned included inorganic colloidal solids
and acrylic polymers. Starting in 1917, several types of chemical wastes
were disposed in various on-site locations with the majority of these
wastes deposited on Megunko Hill, which was used as an unsecured landfill.
Wastes included partially-treated process wastewater; chemical sludge from
the wastewater treatment process; solid process wastes (e.g., chemical
precipitate and filter cakes) in drums; solvent recovery distillation
residue in drums; and off-specification products. Process chemicals that
could not be recycled or reused (including phenol, nitrobenzene, and
mercuric sulfate) were also disposed of on-site~
Chemical wastes were also disposed of in the wetland areas. The eastern
wetland area received waste effluent discharge from various manufacturing
operations in the area. . The northwest wetland area at the headwater of
Chemical Brook contained wastewater treatment sludge and possibly received
overflow from an underground concrete wastewater vault that discharged into
Chemical Brook.
o
Nyanza, Inc., which apparently ceased operations in Ashland in
the most recent dye manufacturing company to occupy the Site.
plant grounds now are occupied by several industrial concerns,
of which is Nyacol Products, Inc.
1978, was
The former
the largest
Nyanza, Inc. and its predecessors originally discharged the dye waste
stream to a concrete "vault" or s~ttling basin adjacent to the main proce~
building. The vault was used as a central sump for the collection of
wastewater from the entire Nyanza, Inc. operation, as well as for other
generating tenants housed in the immediate vicinity. This vault was
approximately 40 x 80 feet and approximately 10 feet deep. The liquid
occasionally overflowed via a pipe into Chemical Brook which flowed into
Trolley Brook and through a culvert to the raceway that entered the,
wetlands along the Sudbury River. The vault was taken out of service in
the 1960's or 1970's and was subsequently filled with sludge and covered
over with fill. As part of an ongoing effort to ease river pollution, the
Massachusetts Division of Water Pollution Control (DWPC) ordered Nyanza,
Inc. to install a pretreatment system for industrial process water and to
discharge the treated waste to the Metropolitan District Commission (MDC)
sewer collection system. Nyanza, Inc. connected to the MDC system in March
1970.
The first type of contamination linked to the Site was mercury, discovered
in the Sudbury River in 1970, as part of an overall investigation of
mercury problems in Massachusetts for the DWPC. A follow up study in 1972
focusing on Nyanza, Inc. revealed mercury contamination in the Sudbury
River caused by uncontrolled'sludge and wastewater disposal at the Site.
Since 1972, several investigations have been prompted by contamination
present at or originating from the Site. From 1972 through 1977, the
Massachusetts Department of Water Pollution Control (DWPC) and Department
of Public Health (DPH) cited Nyanza, Inc., for several contamination
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v
problems associated with dumping activities. Following a 1973 DWPC order
to iDplement a plan to stop furthe~ groundwater poll~tion, Camp Dresser and
McKee, Inc. (CDM) , working for Nyanza, Inc., pe~fo~ed a 1974 Site
ir.vestigation aimed a~ source identifica~ion and devised plans to cont~ol
groundwater contamination on the Nyanza property; however, the plans ~ere
not implemented. In 1979, Edward J. Camille, a property owner, hired
Connorstone" Engineering, Inc. to complete the CDM groundwater pollution
control program. However, the Massachusetts Department of Environmental
Quality Engineering (DEQE; now known as the Department of Environmental
Protection or DEP) halted these plans, pending further investigation. In
1980, DEQE released a Preliminary site Assessment Report summarizing the
site history and findings of previous investigations at the Site (DEQE, .
1980). MCL Development Corporation acquired much of the property in 1981,
and hired Connorstone Engineering, Inc. and Carr Research Laboratory, Inc.
to characterize soil composition and locate sludge deposits.
The Site was included on the original National Priority List (NPL) of
Superfund Sites in 1982 and a preliminary Remedial Action Master Plan
(RAMP) was prepared. In 1984, the Environmental Protection Agency (EPA)
authorized NUS Corporation (NUS) to perform an Remedial "
Investigation/Feasibility Study.
The September 4, 1985 Record of Decision (ROD) divided the Agency's
remedial response into Operable Units for the purpose of addressing
distinct problems. The September 1985 ROD was designated Operable Unit I.
The ROD selected soil and wetland excavation at nine localized areas of
contamination; solidification of water bearing excavated sludge, sediments,
and soil; and placement, capping and consolidation of those "materials with
material left in place on the "Hill" area in the southern pari of the Site.
A diversion trench has been constructed on the side of Megunko Hill above
and around the capped area to divert surface water flow and lower the
groundwater table beneath the cap as part of Operable Unit I. Construction
of the project began in early 1989 and will be complete in late 1991.
In 1985 the DEQE undertook an Interim Response Measure at the Site
consisting of the following activities: fencing the Trolley Brook Road
embankment: placing one foot of clean fill in one of the Site areas to
remove the threat of direct contact: and culverting Chemical Brook through
neighboring property.
In 1986, EPA authorized CDM to conduct additional field investigations to
define source locations and design the remedial action stipulated in the
ROD. The remedial design is complete and construction began in early 1989.
In January 1987, DEQE and the EPA Environmental Services Division (ESD)
initiated a sludge removal action of the contents within th~ vault (see
Figure 2-2). Prior studies by a DEQE contractor indicated that the vault,
and contaminated soil and groundwater in the vicinity of the vault, were a
significant source of organic contamination in the groundwater downgradient
of the area. Contaminants present included, but were not limited to,
trichloroethene (TCE) , chlorobenzene, and nit~obenzene, all by-products of
aniline dye production. Inorganic contaminants found in the sludge
included heavy metals such as antimony, cadmium and chromium. Initially,
the vault contamination investigation was planned within the scope of
Operable Unit II. DEQE and the EPA conducted a subsurface investigation in
the-vault and surrounding area, culminating in a decision to proceed
immediately with remediation of the vault area. The removal action was
conducted by EPA's Emergency Response Team. From October to December 1987,
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665 tons of soil adjacent to the vault were removed; 309 tons were
incinerated, and 356 tons were shipped off-site to an approved landfill.
In March and June 1988, 2,512 tons of sludge from the vault was solidified
on-site and disposed of at an off-site RCRA landfill facility.
In June 1987, EPA author:ced the REM III team to begin RI/FS activities fo
Operable Unit II. Operab~a Unit II comprises groundwater contamination
related to the Site. A third set of RI/FS investigations, Operable Unit
III, is focused on contamination in the Sudbury River. Work on Operable
Unit III is being performed by NUS Corp. under an ARCS contract to EPA.
A more detailed description of the Site history can be found in Section 1.4
of the Remedial Investigation Report.
B.
Enforcement History
On April 4, 1982, EPA sent general notice letters to 18 entities it
believed were responsible parties. On January 22, 1991, based on newly
acquired information, EPA notified approximately 21 parties who either
owned or operated the facility, generated wastes that were shipped to the
facility, arranged for the disposal of wastes at the facility, or
transported wastes to the facility of their potential liability with.
respect to the Site. Some of the 21 parties named in the January, 1991
letters had'been previously notified in the 1982 letters. An additional
owner/operator was notified on June 21, 1991 based on new information
supplied by existing PRPs. On July 22, 1991, eleven parties were removed
from the PRP list. EPA therefore, considers twenty parties potentially
liable to perform or pay for the cleanup of the Site. EPA generally
conducts negotiations with potentially responsible parties (PRPs) as soon
as possible regarding the settlement of their liability at the Site. The
PRPs have formed a steering committee and substantial discussions between
EPA and the steering committee have taken place.
The PRPs have been active in the remedy selection process for this Site.
Technical comments presented by PRPs during the public comment period are
summarized in the responsiveness summary, and the summary and written
comments have been included in the Administrative Record.
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III. COMMUNITY PARTICIPATION
Throughout ~he Site's history, c~IT~unity co~cern and involv~ment has been
high. E?A has kept the cOIT~unity and other interested parties apprised of
the site activities through informational meetings, fact sheets, press
releases and public meetings which have been held on an almost monthly
basis since 1986. These meetings served to update the public regarding the
progress of various aspects of the cleanup, including the groundwater.
. RI/FS.
"
During 1986, EPA released a community relations plan which outlined a
program to address community concerns and keep citizens informed about and
involved in activities during the planning and execution of remedial
activities. .
Upon the start of construction of the cap and diversion trench on-site in
1989, EPA intensified its community relations efforts in response to public
concerns about safety issues related to the cleanup. For ~ several month
period, weekly meetings were held with representatives of the police and
fire departments, as well as with concern citizens and representatives of
organized labor.
On June 27, 1991 EPA made the Administrative
review at EPA's offices in Boston and at the
published a notice and brief analysis of the
News on June 21, 1991.
Record available for public
Ashland Public Library. EPA
Proposed Plan in the Middlesex
On June 26, 1991, EPA held an informational meeting ~o discuss the results
of the Remedial Investigation and the cleanup alternatives presented in the
Feasibility Study and to present the Agency's Proposed Plan. Also during
this meeting, the Agency answered questions from the public. From June 27
to July 26, 1991 the Agency held a 30 day public comment period to accept
public comment on the alternatives presented in the Feasibility Study and
the Proposed Plan and on any other documents previously released to the
public. On July 18, 1991, the Agency held a public meeting to discuss the
Proposed Plan and to accept any oral comments. A transcript of this
meeting and the comments and the Agency's response to comments are included
in the attached Responsiveness Summary, Appendix I.
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IV.
SCOPE AND ROLE OF OPERABLE UNIT (OU) OR RESPONSE ACTION
The ROD for the first operable unit at Nyanza was signed on September 4,
1985. This source control remedy called for the excavation of outlying on-
site sludges and their consolidation under an impermeable cap. The con-
struction of this remedy is now nearing completion. The third operable
unit, dealing with contamination of the Sudbury River and its tributaries,
remains in the RIfFS stage at this time.
The selected OU II groundwater remedy was developed from components of
different management of migration alternatives to obtain an approach for
groundwater remediation. The selected remedy is an interim remedy. An
interim remedy is designed to take action to protect human health and the
environment in the short term while additional information is collected to
better assess the aquifer and contaminant response to remediation efforts.
The interim remedy will operate for a minimum of 5 years after which time a
final remedial action will be developed. A final Record of Decision (ROD)
for groundwater will be based on the data collected during the design,
operation, and monitoring of the interim remedy. Additional interim
remedial action(s) may be proposed if data collected prior to the final ROD
warrants.
In summary, the remedy provides for: 1) extracting contaminated ground-
water from the northern portion of the Site near the railroad tracks and
industrial park, and optionally at. the southern border of the cap now under
construction on Megunko Hill for a minimum of 5 years; 2) treating the
groundwater with a combination of physical and chemical processes; 3) dis-
charging the treated water into the Sudbury River; 4) using institutional
and access controls to limit exposure to contaminants; 5) performing pump
tests in the eastern portion of the plume to help determine the feasibility
of cleaning up groundwater in this area at some future point; 6) installinq
additional deep bedrock wells to more fully define the depths and locatio'
to which contaminants may have migrated; 7) performing continuing mo~i-
toring of selected existing residential and monitoring wells and limited
surface water testing to track any further progress of the plume; 8) in-
specting the Megunko Road water line; and 9) performing certain pre-design
studies to aid in the design of the selected remedy.
,
The first operable unit addressed contaminated sludges and soils by
excavating them from outlying areas, and consolidating them with sludges
already on Megunko Hill under an impermeable cap. The first operable unit
ROD also included an upgradient diversion trench to preclude contact with
groundwater and surface water runoff with the buried material. Construc-
ti6n of the first operable unit iemedy is expected to be completed in late
1991. . .
The second operable unit interim remedial action will serve to collect data.
to refine the cleanup time estimates for the final Record of Decision, and
will in the interim address the following principal threats to human health
and the environment posed by the site: migration of contaminants in
groundwater, risks to human health associated with potential future
consumption and direct contact with groundwater, risks from present and
potential future inhalation of evaporated groundwater contaminants, and
degradation of the Sudbury River and wetlands due to the natural discharge
of contaminated groundwater.
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A.
General
SUMMARY OF SITE CHARACTERISTICS
v.
Chapter 2 of the Feasibility Study contains an overview of the Remed~al
Investigation. The significant findings of the Remedial Investigation are
summarized below. The RI report utilized information developed by previous
studies and information developed as part of a two-phased field program
conducted specifically to evaluate the Nyanza II Groundwater Study. The
specific objectives of these field investigation activities are summarized
below:
o characterize the hydrogeologic regime, including the geologic
deposits underlying the study area, the direction and rate of
groundwater flow, and the interaction between groundwater and
surface water in the wetlands and the Sudbury River;
o assess the nature, distribution, and migration of
contaminants in groundwater, surface water, sediment, subsurface
soils, and bedrock;
o assess the degree to which future migration of contaminants
may pose a threat to public health, welfare, and the
environment; and
o obtain groundwater quality data to assess the applicability
of groundwater treatment technologies for the FS. .
To achieve the above objectives, the two-phased field program commenced in
February 1988 and continued until June 1988, with subsequent water level
measurements in June, October and November of the same year. The second
phase of the program was conducted from September of 1989 until February
1990. The analytical data from the two phases are generally referred to as
"1988" or "1990" data. The following field activities were conducted as
part of these investigative efforts:
o
o
topographic and property location survey;
geophysical investigations including seismic
refraction, electromagnetic and resistivity surveys;
exploratory borings in the vault and lower industrial'
area to augment Operable. Unit I data;
subsurface drilling, and monitoring well and well point
installation;
chemical sampling of
subsurface soil, and
aquifer permeability
packer testing;
water elevation measurement;
well inventory;
treatability studies;
ecological risk assessment; and
public health risk assessment.
o
o
o
groundwater, surface water,
sediment;
t~sting includin~ slug testing and
o
o
o
o
o
o
The results of these efforts are presented in detail in the RI report.
Plate 1 is a base map showing all monitoring wells and other features of
the study area. The treatability study results were presented ~nd
discussed in the 1990 "Treatability Study Evaluation" performed for EPA by
Ebasco Services, Inc..
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B.
Topography
The study area lies within the New England physiographic province. The
topography is strongly influenced by underlying bedrock and has been shaped
by glaciation into rolling hills dissected by postglacial drainage system~
Thick glacial deposits typically overlie the bedrock in valleys and areas
of low relief, while thinner deposits blanket slopes and upland areas.
Surface elevations range from over 350 feet above mean sea level (msl) on
Megunko Hill to 180 feet msl along the Sudbury River.
Topographic features of interest in the study area include:
o The northern flank of Megunko (alternate spelling: Magunko)
Hill, which dominates the s~uthwestern corner of the study area.
The Hill section of the former Nyanza property is located here
(see Figure 1-2). The landfill constructed under the Operable
Unit I ROD has significantly altered the topography of the
Megunko Hill area.
o
The lower industrial area located along Megunko Road.
o The wetland near the eastern boundary of the former Nyanza
property. This Wetland is bisected by an abandoned trolley bed
embankment. Trolley Brook originates on Megunko Hill and. flows
a~ong the western embankment of the trolley bed and into a
wetland near Megunko Road. The eastern wetland lies east of the
trolley bed and merges with the Trolley Brook wetland via a
culvert. Trolley Brook flows northeasterly along "the western
side of the trolley bed, under Megunko Road, and into Chemical
Brook.. The Trolley Brook Wetland was remediated under Operable
Unit I during 1990. .
o The western wetland in the northwestern corner of the former
Nyanza property, which forms the headwater of an intermittent
stream, Chemical Brook. Chemical Brook flows along the northern
boundary of the Nyanza property parallel to the Conrail Railroad
tracks, converges with Trolley Brook, and presently flows
northeasterly through an underground culvert to its confluence
with the Sudbury River near Concord Street. The western wetland
and Chemical Brook were remediated in 1990 as part of
construction activities associated with Operable Unit I.
o A broad, low-lying area located between the Sudbury River to
the north and Megunko Hill to the south. This area is bisected
by the Conrail Railroad tracks. The Sudbury River flows
easterly to the Myrtle Street dam and southeasterly downstream
of the dam.
o The Sudbury River, which flows into the Framingham Reservoir
No.2 (See Figure 1-2). Classified in 1872 as an emergency
water supply for the Metropolitan Boston area, the reservoir has
not been used since 1946. The Sudbury River joins the Assabet
and Concord River systems, which flow northeast into the
Merrimack River located in the northeastern part of the state.
The Sudbury River is being investigated in conjunction. with the
Third Operable Unit for the Nyanza Site.
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c.
Geology
The Site directly overlies glacial sed:~e~~s, which i~ tu=n overlie
granitic bedrock. The bedrock 5~=face is ur.ju~a~ing and slopes dc~r.warc
from Megunko Hill toward the Sudbury River with a small trough paralleling
the Sudbury River in a general east-west orientation between Pleasant
Street and the railroad tracks. Depth to bedrock generally increases from
the hillside (5 to 10 feet) toward the lowlands and the Sudbury River (20
to 50 feet). The greatest depths to bedrock (50 to 100 feet) occur in what
is interpreted as a bedrock depression, or trough, parallel to the southern
shore of the Sudbury River and then trending south in the general area near
the intersection of Park Road and Summer Street.
Bedrock contours were developed from geophysical soundings, bedrock
corings, and refusals in overburden borings (see Figure 5-1). The highest
elevations, along Megunko Hill, decrease radially out from the Hill into a
valley in the lowlands before beginning to rise again on the north shore of
the Sudbury River. A meandering bedrock trough exists in the center of the
study area and roughly parallels the Sudbury River. The trough probably
represents a preglacial river course for the Sudbury River.
The total observed thickness of glacial sediments varies from 10.8 feet
(MW-10B) to greater than 110 feet (MW-404A). Glacial sediment cover is
generally thinnest on Megunko Hill and thickest in the bedrock trough.
The till consists of a non-stratified and poorly graded mixture of
clay/silt, sand, gravel, cobbles, and boulders. It can be deposited
subglacially during glacier advances, or as draped deposits when entrained
debris melts out during glacial recessions. Glacial till occurs on Megunko
Hill above an elevation of approximately 200 feet msl as observed in a road
cut on the north flank of Megunko Hill.
Glacial lake deposits cover the lowlands to the north on both sides of the
Sudbury River. The deposits range in thickness from 5 to 50 feet but
commonly occur in deposits 20 too 40 feet thick across the lowlands, with
the thicker deposits in the bedrock trough. Typically, three types of
materials comprise these glacial lake deposits: boulders and cobbles,
glaciofluvial sediments or glaciolacustrine sediments based on the dominant
depositional environments in which they were created.
P.
Hydrogeology
This section summarizes the hydrogeologic findings for the study area and
includes a summary of the hydrogeologic evaluation. Additional detail$ and
specific data supporting the hydrogeologic evaluation are presented in the
RI.
Groundwater flows radially off Megunko Hill. West of the MW-113 couplet,
flow is to the north-toward the Sudbury River. To the east, groundwater
flow is northeasterly, becoming east-northeasterly near MW-201 (see Figure
5-2). This shift may be related to the elevated river levels caused either
by the dam at Myrtle Street or by flow through the bedrock trough located
north of the northeast sections of the lower industrial area. Downward
hydraulic gradients along the Sudbury River between MW-304B and WP-105 are
indicative of induced infiltration fro~ the river to the adjacent
-------
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-------
overburden aquifer in the north central part of the study area. However,
depending on the river stage and piezometric head, the area around MW-304B
may periodically discharge to the river; the lack of river stage data
prevents further verification of this scenario.
Groundwater probably discharges to the Sudbury River above MW-304 and belc
the Myrtle street darn; the river reach in between is likely an area of
induced infiltration from the river. The probability of groundwater flow
beneath the river is very low based on the following:
upward gradients at MW-305, MW-405, MW-408, WP-102 and
occasionally at MW-304;
the 15 to 25 foot rise in bedrock over the short distances from
the southern to northern shores of the river;
the probable deflection of flow through the bedrock trough; and
consistently higher groundwater elevations on the north shore of
the river compared to the south shore.
Measured horizontal hydraulic gradients in the overburden ranged between
0.234 and 0.268 ft/ft in the upland portions of the Site and between 0.004
to 0.006 ft/ft in the lowland portions. Bedrock horizontal hydraulic
gradients ranged between 0.112 to 0.230 £t/ft in the uplands and 0.003 to
0.007 ft/ft in the lowlands.
E.
contamination of Affected Media
1.
Groundwater
~
The groundwater assessment was based on the 1988 and 1990 sampling cata
from wells installed during these field investigations and wells installed
during previous investigations. Most monitoring wells were screened at two
different depths. Depending on their depth, wells installed during the
Operable Unit II remedial investigation were designated by well sequence
numbers greater than 100. Overburden wells are designated with the suffix
"B", and bedrock with the suffix "A". Existing wells installed prior to
Operable unit II were designated by well identification numbers below 100.
These overburden and bedrock wells were generally differentiated by the
suffix "A" or "B", respectively.
The results of the 1988 and 1990 groundwater sampling program contamination
assessment may be summarized as follows:
o
Major volatile organic conta~inants include 1,2-DCE, TCE, and
chlorobenzene. These three compounds generally exceed their
respective MCLs or MCLGs in wells where they were detected.
o
Major semivolatile organic contaminants include 1,4- .
dichlorobenzene, 1,2-dichlorobenzene, nitrobenzene, 1,2,4-
trichlorobenzene, and aniline. All of these contaminants were
detected at numerous sampling locations at concentrations
exceedin~ 1,000 ug/l. concentrations of 1,2-dichlorobenzene,
1,4-dichlorobenzene, and 1,2,4 trichlorobenzene exceeded existing
or proposed MCLs in many wells in which they were detected.
-------
o
VOC anj SVOC grounj~ater c=~~a~i~a~ic~ a??ear to origina~e !ro~
at least three Site ar~3S. The ~ajcr s~~rce appears to be ~he
vaul:. nea:- M"";-E?:'-2 I as seen ty the ".;ery hi:;h \"::: and SVOC
concentrations observed do~ng:-ajient in MW-113. Secondary
sources appear to be Megunko Hill and the northeastern lower
industrial area. The vault was excavated during a removal action
in 1987-1988. In addition, metals bearing sludge deposited on
Megunko Hill and in the northeast lower industrial park are
currently scheduled to be remediated as part of Operable unit I.
Furthermore, it is uncertain as to whether the patterns of VOCs
and SVOCs in soil borings taken from the lower industrial area
reflect groundwater contaminant migration in the overburden and
bedrock from upgradient sources or past disposal practices in the
immediate area of the borings.
o
The general distributions of VOCs and SVOCs suggest a highly
contaminated groundwater plume apparently originating from the
general area of the vault and migrating in an easterly and
northeasterly direction toward MW-405 and the Sudb~ry River.
Immediately downgradient from the vault and Megunko Hill, voc and
SVOC contamination is generally one to three orders-of-magnitude
higher in the shallow bedrock than in the overburden. Elsewhere,
concentrations are more evenly distributed between the overburden
and bedrock. The high concentrations immediately downgradient of
the vault suggests the past or current presence of nonaqueous
phase liquid.
o
o
The significant changes in bedrock contour elevations between MW-
405 and MW-403 and vertical gradient data suggest that the
contaminant plume is not migrating under the.river towards MW-
403, but is probably discharging to the river. Elevated sodium
levels in wells to the southeast of MW-405 might support the
hypothesis of some plume migration in this direction.
o
Several pesticides were detected in only a limited number of
wells sampled, and these at relatively low concentrations.
Included were heptachlor, 4,4'-DDT, beta-BHC, delta-BHC,
dieldrin, and gamma-chlordane. However, heptachlor.
concentrations exceeded its MCLG in all five wells where it was
detected. Because of the low concentrations of pesticides
detected and their limited distribution, it is difficult to
locate specific sources of pesticide contamination or to
completely confirm a site origin.
o
Cadmium, lead, mercury, and other metals were detected in a
limited number of wells in the 1988 and/or 1990 sampling programs
at concentrations greater than their respective MCLs. Generally,
the migration and exceedances of MCLs by metal contaminants is
limited in comparison with the degree of organic contamination
found at the Site. Inorganic contamination appears to originate
from several Site areas. One source exists on Megunko Hill.
Other sources appear to be in the western wetland, and in the
northeastern lower industrial area south of ~v-l09. Contaminated
soils and sludge deposits in those areas were remediated as part
of Operable Unit I.
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o
I~8rga~ic conce~tration jis~~itu~ions te~heen the overburden a"j
sr.sllow bedrock wells appear to be so~ehhat conta~inant-specific.
o
Sodium concentration contours suggest that it is potentially a
conservative (non-attenuated) Site-related contaminant. Sodium
concentration contours also support the hypothesis of potential
groundwater and organic contaminant transport to the southeast ot
MW-302 and MW-405 parallel to the river.
Contour maps showing the prevalence of aniline, nitrobenzene,
dichlorobenzene, and trichloroethene in overburden and bedrock aquifers are
shown in Figures 5-3 through 5-10.
2.
Surface Water and Sediment
Analytical surface water and sediment results were derived from the limited
1988 field efforts and other previous studies conducted at the Site. The
sampling locations and the analytical results for these media are presented
in the RI report along with a more detailed presentation of the contaminan~
assessment and distribution. It should be noted that surface water and
sediment issues will be addressed in Operable Unit III.
The results of the Operable Unit I and II studies indicate that both
surface water and sediment are contaminated with Site-related organic and
inorganic contaminants. VOCs, SVOCs and heavy metals were all detected in
the surface water or sediment of the eastern and western wetlands, Trolley
and Chemical Brooks, the Sudbury River, and near the confluence of Chemical
Brook and the Sudbury River.
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VI.
SUMMARY OF SITE RISKS
A Risk Assessment (RA) was performed to estimate the probability and
magnitude of potential adverse human health and environmental effects from
exposure to contaminants associated with the Site. The public health'risk
assessment followed a four step process: 1) contaminant identification,
which identified those hazardous substances which, given the specifics of
the site were of significant concern; 2) exposure assessment, which
identified actual or potential exposure pathways, characterized the
potentially exposed populations, and determined the extent of possible
exposure; 3) toxicity assessment, which considered the types and magnitude
of adverse health effects associated with exposure to hazardous substances,
and 4) risk characterization, which integrated the three earlier steps to
summarize the potential and actual risks posed by hazardous substances at
the site, including carcinogenic and non-carcinogenic risks.- The results
of the public health risk assessment for the Nyanza Chemical Waste Dump
site are discussed below followed by the conclusions of the environmental
risk assessment.
The summary of contaminants of concern -found in groundwater, surface water
and sediment is found in Table 6-1. These contaminants constitute a
representative subset of the contaminants identified at the Site during the
Remedial Investigation. The contaminants of concern for each medium were
selected to represent potential site related hazards based on toxicity,
concentration, frequency of detection, and mobility and persistence in the
environment. A summary of the health effects of each of the contaminants of
concern can be found in Appendix Bof the Risk Assessment.
Potential human health effects associated with exposure to the contaminants
of concern were estimated quantitatively through the development of several
hypothetical exposure pathways. These pathways were developed to reflect
the potential for exposure to hazardous substances based on the present
uses, potential future uses, and location of the Site. The following is a
brief summary of the exposure pathways evaluated. A more thorough
description can be found in Section 4 of the Risk Assessment.
-At the Nyanza Operable Unit II study area, risks were assessed for exposure
to contaminants in groundwater, surface water, and sediments. Table 6-2
summarizes the exposure pathways investigated, along ~ith the sources of
data used to assess exposure point concentrations.
Although groundwater is the most extensively contaminated medium at the
Site, there is no current exposure to groundwater via ingestion as a
drinking water supply. The area in the vicinity of the Nyanza Site is
supplied by a municipal water supply wellfield located approximately two
miles west of the Site. Exposure to groundwater contaminants through the
use of groundwater for domestic purposes could occur in the future if the
aquifer was developed for this purpose. Groundwater exposure through
domestic use is only possible in the future if water supply wells are
installed in the shallow or bedrock aquifers.
People may also be exposed to groundwater in residential basements, since
groundwater has been found to migrate into basements. Although the present
risk from exposure to basement seepage contamination is reportedly low
(based on trace levels of contamination observed during a survey of 6
basements), risks were assessed using the measured levels of contaminants
found in the shallow overburden groundwater wells during the 1988 and 1990
investigations and projections regarding their contributions to indoor air
-------
TABLE 6- 1
S~c~y of Cor.!am;nants of Concern Selected for the
Nyanza Site Ground~a!er Operable Unit
1988 end 1990
Contaminant
1988
Ground~ater
1990
Ground~ater
Surface
Weter
Sediment
Vola!' le O'Qa~;cs
, Benzene
2-Butanone
Chlorobenzene
1.2-0;chloroethene
Methylene Chloride
Tetrechloroethene
Toluene
Trichlo'oethe'1e
Vinyl Chlorice
Se~;VQ!a~; Ie O'~a~ics
Ani tine
Eie',zid1ne
I.-Cn~orca"; line
2 -:r I ::~o;:>t'e'"lc:
'.2-dicnlorODe'Ze'"le
'.3-dic~lcrooe~ze"e
, .1.-dicr.I::'ooe'1Ze~e
3.3-c'me~.,:oerz'='''e
b;s-(Etny:ne,,:)p'~'"Ia:a!e
~ap..t~ale"'e
N; ! - cbe~,z e~e
N-~;trCSjC;~e~1.a-;ne
~.~;trcs~c:_~.pr:~y;a~~ne
Fe'~a:..c':~e-:.
',2,k.~ric~~:~~oe~:e"'e
;:es.~i:~o~s
Cielc-i',
~e::a:'.c'
...
It"\:~:;a-:=5
A"timoroy
Arser,; c
'Beryl I i~
Cacri 1.11',
Cr.r:)!!" .rr
Copee-
Lea:
Manga'1ese
"'e""c:..Jr'.,-
h\CKe~
)( )(
)( )(
)( )( )( )(
)( )( )( )(
)(
)(
)( )(
)( )( )( )(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
)(
x
X
X
)(
X
X
)(
X
)(
X
X
X )(
)( )( )(
)( )( )(
X )(
X X X X
)( )( )( X
X )( )( )(
)( )(
)( )( )( )(
X X
POOR aUAL\T'(
-------
HS." f:-2
E'~:s~-e 'a:r~ays
~7=~=a !! . C~C~~:-g~er S:~=y
~S'\2~=. ~2ssa:~~se::s
Mediun
?cint of
E..pcsure
R=~:e cf
E.r;;:S..Jre
Expos...e
Status
Exposed
Population
Data Used
10 Est imate
hposures
(jround",ater
Oo","g'a::'ent
Area
Ir.;E>: icr-;:
In": . 0 t ; =" C f
.::s c~-in;
Currer.!
None
1988, 1990
Future
Users of
..ells dug in
vicinity
S"',;...er: "'.;;
Oe"",.Z!! c.:~ta=t
c.;rin; ..ashi"g
Base~'e'":t
See;o;e
C::",-;-a=:e-:
,e.-,,::
Ir.~a:c~ic('l ~
C'er-:-,: "
Curren: &
Fut...'e
Mousehold
residents
1988, 1990
,....._._~.
~.. .. c- .
.. c...!
1';E>:':-
C..-re'":t
None
1988
l..-r;c
:...:_-;.
l:se"s ct
~e. t s c...; 1 ~
" i , j ;; ~ t,.
JIll ~; - -.,: ~':.
,e.-eo
;-;-=s: ::-
C..-re'.:
h:"\e
1988
'.t.""
\...'se"s :f
"'-:=. . ~ 0...'; 1;,
- . : ~ ...., : t 'y
S.Jdo:e
OIate"
.. .-'
.' -
C---e-: &
E"::- ~
... - - : ;;:: ~
'...:...-e-
:~i :d:-en
~aj;n3
1988
:=:~~--
... -. . . . --
-:-. ..:: -::"
Se:;-e-:,
Eas:::-"
.... . -- .
:_.._~-: &
C"':: t ="en
""a:::: /"',g
1988
...~: ..=- ==-
- .
F...:...-e
-... - ...-
. -'.:. ..
POOR aUAL\TY
-------
levels, to provide a conservative estimate of future risks through this
pathway. Exposure to surface water and sediment contaminants may occur via
dermal contact and ingestion under existing conditions, as well as in the
future. The potentially exposed populations and pathways of exposure for
each medium are discussed in the following sections.
A.
Groundwater Exposure Scenarios
Two situations in which exposure to groundwater may occur in the Nyanza II
study area were considered: groundwater as a public water supply, and
groundwater seepage into basements.
1.
Groundwater as Public Water Supply
The area in the vicinity of the site is supplied b1 a public water supply
located outside of the study area. Therefore, local groundwater is not
currently used as a drinking water supply. Future development in the area,
however, may require the installation of new wells. If water supply wells
are installed in the future, exposure to contaminants present in
groundwater could occur in a variety of ways. These. include: 1)
ingestion; 2) inhalation of chemicals released into air during household
uses such as showering; and 3) dermal absorption of chemicals from.
household water uses such as washing. The assumptions made to assess
exposure through these routes are described in Table 6-3.
For each pathway evaluated, an average (most probable) and a reasonable
maximum exposure (realistic worst case) estimate was generated.
corresponding to exposure to the average and maximum concentration detected
in that particular medium.
The estimated groundwater concentrations derived from the 1988 and 1990
data are summarized in Table 4-3 of the Risk Assessment which is included
as an A~pendix III to this ROD. Included in Table 4-3 are the arithmetic
mean and maximum values and frequencies of detection of contaminants broken
out into individual exposure areas: Megunko Hill, the vault area, and the
downgradient area.
2 .
Groundwater Seepage
The second groundwater exposure scenario evaluated is associated with
seepage of shallow groundwater into residential basements. Previous
residential sampling conducted by NUS Corporation for EPA detected low
levels of contaminants in water collected from several basements
downgradient of the Site. In addition, air samples collected from.
basements located downgradient of the Site did not indicate significant
impact from contaminated groundwater.
Residents of houses. with basements may come into contact with contaminated
groundwater basement seepage. The most likely routes of exposure to
contaminants as a result of basement seepage are dermal contact, ingestion,
and inhalation. Assumptions used to assess exposure through these pathways
are described in Table 6-4.
air
To estimate exposure point concentrations of puddled water standing in
basements or of submersible pump discharges, it was assumed that the
contaminants found in shallow groundwater monitoring wells in the
downgradient area migrated into residential basements. Thus, the
groundwater contaminant concentrations that could potentially migrate
into
-------
T~S.E 6-3
O~o', ,
Ce.~c. a~= :~~~:c:i:~ E~p:s~ie tc ~~c~~~.ater
05 a t:~=~.~ :~in~in; ~c~e~ S~pp~y
~il~:a ! I - Gr:~-:.ater St~:y
~~~\a~=, ~ossa:~~~e~ts
D;1~~i~;. ~=S~~~;, an: SnOwerin; Path.ays
parame:er
ASSlr1pt i on ~I
Ages
Adul t
Average B~dy we!g~t ~
70 kg
Average S~rfa:e A"ea E'D:~e~ !.
2300 em'
Incidental Ingest;:" fr:~ ~a~"";
o l
:~;est;~~ as ~-~~~;~=
~=:e'" -
2 l! da y
J'n~a: a: ~ c" Ra:e :
1.3 rr,!/hr
Fre~~e~:7 :~ E.e~:~
365 e.'er;:s/year
C~-a:':- :' E.e-:
C.25 hrs sho.ering.
C. 17 hr pcst-sho.ering
2 hr (.ashing)
C..."at':"
:' :"':::_.i? ~
7C years (Carcinogens)
~::e>:
i/
L'S~::'. ';:::. s...;:.=..~-:,=. ~.~. ':'~:::?::~-;.": :...'=5-.:~
S~:e-f_-: :-:;.~-. :-~~: ~'~a., _£~;; ~~;.:- .
of;'" tlie
~/
"c" :~
0-: ;:'''~=-;''''s
::...":""; ...:-::~a.:'.: c:::;-,;::~~
s..:" as
.1)':.; ~an:s. c:sres and clothing; Anderson et at..
1;~-
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L.'s:: ~ I
C ,:.
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- - - . . - . . . . .
- .-
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: : -= . = : ~: ~ .. ;
POOR QUAL\TY.
-------
1:'5_: 6.'-
E~~:s~~e tc G-~~~j"Q~er
tiC. 6=Se-~it See;a;~
~Ta~:= i: .. G-:.~:"C~~~ St~Oi
AS~. a"',=, ~assa::h~se'::~s
F'ara;;eter
Ass"J-I;: 1 0" !'
A;es
Ad., t
Average Body wei;ht V
7: K;
Avera;e Surface Area Expose: !
'00;:; cm'
Average In~a~a~io~ Ra~e !
'.3 11".' /hr
rncide"'~at Ir,;~s~;::""
, r-~/eve...,t
Freq.e~:y c' E.c:s.-e :'
,:~ he.,:s/yea"
f'\ _....; ~...
""... CI, ...'
::" £,e-:
~ ~~ ('n~a.a~i:~)
C. ~ r,r (derrr,a l)
D"."t':- o'
:J=:~-~E
7: y'e".s
"c~e5:
. '.'
~rI::e"'5:"',
e ~ a.. : ;:!..
f:
A5;.....~,e: ~::e-:; a.:.,. e)::~~: s..
:- s--~~:~ ~"e= :' 2,::: :-'
a~= a "a:~:" :~ ~~', :: a:::_-~
~:. :~~ ..i::::':- :".=: 15 ~:,,~.'1
t: be a::......=.., e.::~e:.
........-
":":.
~...::, ;'-~-: =.
III'S..
~ss~£;-~-: G_:::-:= ':~
....= ::. -.~". --
. "' .. -- . --
-
:.c't "-c.,
~I
t".~:::' ;e;':-:.
~5~:~. ~;:~. S_==----:
..cs":";::-, :.:.
: .::~---=-
:... ...=... "' - .:. -"
--.... . .
"":.- :.
':.I
~i
t. e,e-:s :~.. ..~~.,
:2 "'"~-:-.:: ~~::..
k; = "
........- . ..-
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= sc_:-" ceo:
"' '. -,
.. . '" ..
OR QU~l\l 't
-------
basements were assumed to be the same as the concentrations in shallow
wells defined as overburden wells. Table 6-5a and 6-5b present 1988 and
1990 exposure point concentrations, respectively, for basement seepage
based upon data sets comprised only of samples from downgradient overburden
wells.
Inhalation exposures due to basement seepage were assessed using a model
developed by Murphy to estimate the basement air concentrations for
volatile contaminants associated with the presence of contaminants in
sumps. Further detail on this model is included in the Risk Assessment.
3.
Surface Water and Sediment Exposure Scenarios
The contaminated surface water bodies in the Nyanza II study area are the
eastern wetland and Trolley Brook. The most likely population to be
exposed to contaminants at these locations are older children and
adolescents wading in the water. Risks associated with dermal contact and
incidental ingestion of the surface water were calculated for this medium.
Exposure parameters used to assess risk at th~se locations are shown in
Table 6-6.
Exposure point concentrations of contaminants at these locations were
calculated using data from 1988 samples SW-101 (eastern wetland) and SW-102
(Trolley Broo~) (see Table 6-7). The maximum detected concentrations and
arithmetic means were used for the risk calculations in the realistic worst
case and most probable case scenarios, respectively. However, where the
data set consisted of only one sample, only most probable case scenarios
were evaluated.
4 .
Exposure to Subsurface Soil
Potential contaminant exposures and risks associated with future exposures
to subsurface soil are discussed q:lalitatively in Section 6.2 of the Risk
Assessment. For each pathway evaluated, an average and a reasonable
maximum exposure estimate was generated corresponding to exposure to the
average and the maximu~ concentration detected in that particular medium.
B.
Risk Characterization
Excess lifetime cancer risks were deterffiined for each exposure pathway by
multiplying the exposure level with the chemical specific cancer potency
factor. Cancer potency factors have been developed by EPA from
epidemiological or animal studies to reflect a conservative "upper bound"
of the .risk posed by potentially carcinogenic compounds. That is, the true
risk is very unlikely to be greater than the risk predicted. The resulting
risk estimates are expressed in scientific notation as a probability (e.g.
1 x 10'6 for 1/1,000,000) and indicate (using this example), that an
individual is not likely to have greater than a one in a million chance of
developing cancer over 70 years as a result of site-related exposure as
defined to the compound at the stated concentration. Current EPA practice
considers carcinogenic risks to be additive when assessing exposure to a
mixture of hazardous substances.
The hazard quotient was also calculated for each pathway as EPA's measure
of the potential for non-carcinogenic health effects. The hazard quotient
is calculated by dividing the exposure level by the reference dose (RfD) or
other suitable benchmark for non-carcinogenic health effects. Reference
doses have been developed by EPA to protect sensitive individuals over the
-------
TAS.E 6-5a
EA~~s~-e Pci~: C:~:e-:"a:i=~s fc" Grou~~~a:er i~ Sasement Seepage
C:~~;~a=;e~~ Cve~b~~~;: ~eLls
~,2~za II . '9~S Gr~~~~ft=~e~ St~dy
As~; a-.c:, Massa:h",setts
Contami nan:
Max ;m..Jr."
(uS/.)
Arithmetic Mean
(ug/ l)
Frequency of
Detection
VOCs
Benzene
Methylene Chloride
1.2'Dichloroethene
2-Butanone
Trichloroethene
Toluene
Ch l c~cbe~.ze"e
sv::s
1,3-~;:r:crcbe~:e~e
',4.01=~~c~:b~~:!~e
1.2'O;:n.c~cben:e-e
~-~itrosc-cl'n-~-::, ,a-'''e
..it!"':::o~"',:e'ie
',2".Tr;c~:or::~-:e-e
~c~l..t!"'c.e"',e
An; l; "'e
l=e5-':::'=~S
J.ie;~c:"'.::-
Cie:~-:r.
Ir:-::.-':"
Ar.<:: -,:-,)
A~sr:- :
6e-,..'.-
Ca::J-'.-
Cr. -0.' ~~
C:;:;;:;e-
Lea:::
Ma":a-,e~e
Mer:...-y
I/Icke.
3.. 48.3 9/21
93~ 86.0 5/21
1,6C: 16':' 15121
3;: 13 It 3115
5, 'C: 1.2;~ 21121
:' 45.3 4/21
7,;:: ',:5: 21121
33: t5.2 3121
3-- 137 12119
'-
t.::: ' ,5:: 15/18
;t: 1 ~.:. 3/10
5,3:: 3c: 4120
5, .:: 562 10/18
.-- 123 4/21
,"".
2-.::: '. 2~: 9115
5.... -
:.3:
3/21
3/21
: . .:;
C.:~~
- - ~2~ 9/21
. -. y 5.33 6/21
......... ~:.8 17/21
2::.: ~. S ':' 5/21
~ - '0 - 10/21
:...... ,_...'
3 ~ - c. 9.38 7/21
32.: n.t 17/21
126,::: 18,;:: 21/21
e.23 c. 68 9/21
1.73 7; -, 15121
POOR QUALITY
-------
H,6.t 6'5b
EA~:5~~e ~oi~t Concentratjo~s
fer C":~~~~ate- in 6ase~ent Seeps;e
C:~-;-a:'e~t Cve-~~-ee~! -ells
~ro~:o II - 1;;: Gro~n~~a~er StuOy
As" ~ 0""'::, fw!assa.:h.,isetts
Compound
~=, \!'I'"'..J"".
Ar i tnmet i c
Mean
(u;/l)
Frequency of
Detection
(u;/, )
VOCs
Benzene
Cnlorobenze"'e
'.2'Dichloroet"ene
Tetrsehlorcet"e-e
Tol..ene
T r i C h ~ C ~ oe t..., e-,;
~
Ar, ~ line
6enz;::,r,e
6is(2'et""re.,. ;:-:-a.a:e
I.'Cnivea-.:: '-e
2'C~.c-e:"e-:.
1,3':'er .:-::e-:er!
',"Cic~.:~:te~:!~e
',2.~::"'::~:::~-:~-~
3,31 - ~ 1 ~'e:" 1 :~-.: . :. ~e-
~.~i:~:s:= :..:'-:.=-....~
"o~"::"'c:e"'e
..,: r::e"'::e-'E
Pe~:a:".:-:;"~-:.
1,2,~-'-;:".:-::e-:e-~
; ,..:..: =- : :' 5-
A-:' - :-)
Arse,.,:
6e"y~! 'J':"'
CSCl"': u'"
ChrOriiul'T'
Copper
Leae
Ma!'1sa""\ese
Here..-)
Nickel
77.5 21..1 6/15
',6:: 1,233 10/1 5
36: 71..0 6/15
2~ 22.7 3/15
t 20.7 "'5
....e:: 1,GEE 11/15
"','.... 1,1.37 8/11.
0/11
3; e.e 1/11
. 0 6.5 2/12
5.0 3/12
-~ ~ 3.1 7/11.
I.:: ,- 8/15
..-
2,-:: t~- 10/15
0/1'
0/11
, . ~ 35. c. 6/15
,. r: . r; 6/13
0/12
::: 7:.1 6/11.
2-.3 1/1':'
," - 0 6/11.
'-~
-y t - 7/15
.."f
0/11.
1 , ~.: e2.2 3/15
5: e.7 3/11.
13.5 2.e 6/15
r;-, . -. 1 t, 1 t:. 15/15
--
5.: C.8 6/11.
53: 67.0 7/15
Ind:ea:es corta-'ra-: n::
Of: ': :;: .... ~.. '. ~ = - e:: .
POOR QUAL\\'1'
-------
TAo.E 0-6
Cra. a~:; :=-ra~ E':;:>-"e t:; S-"~a:e Ioater
at T":~ .ey 6ree.. a".:; Easterr. lOet land
~ya"za :: - ,;~~ ~":~~:;.ate" St~dy
As~ ,a~:, ~ass~:n~settS
Parameter
Ass~t;on ~I
Age
8-18
Average Body lOeig~t V
1,6 kg
Average Surface Area E.pcse: V
1,000 em'
Amo~nt of Ine;de~ta~ Ingestior
1.0 ml/event
Freq~eney of Eve'"\ts !:
72 events/year
Duratien cf e-e":
2 hOolrs
D.,rat;er of e,:;:s_-e
10 years
I;::es:
y
V
~/
';:./
A~je"s,:"', e: c." 1;:-
ha""l:::s I B:"'r'5. cOO',: 'ee!; A"'::~"s:- e: c.., ~,;:-
12 e",e-:sr~:-:", t. ....:...:..~ ,~.::-
I.; = iJ;.'.:;"'c-:; :-' = s:-=.; ::e-:'-~~~-s:".
= :'"":
. ; t e" s
POOR QUAL\TY
-------
(
HS.: 6,7
S.rT.,,-,. S:,,:'st;:~ f:- Se.e::e::: S';-'a:e ~a:ec Sa,",;~es
Atl Lc:a:I:f""s: T~:..e., S"c:.. a'1C :as:e:-r, .Iet{ar"ie!
~ra~za II . 1gee G;o~nj~ater Study
~>-:a,:. ~a~sa:r.;se:ts
Co~o~nj
~a,,~;.~-
(~;: l)
Arith"',et ic 11
Mea:-,
(...;Il )
Contami nants
of Concern
Frequency
of
DeteCtion
~
Chlcrcbe~zeC\e
1.Z-Dichiocoethe,e
Trichlorcethe~e
~
',2.:i:~~c~:=e~z~-e
hi: r::.::e-,ze~e
',2...~ri:~.:"=:e-:e-e
A:e-ao-:.,a.e-e
Pr.e-,c-:I"'r-e-.=
A-':-'-o:e"'.e
01 -r,.::...:,. .:-:-Eo.;:e
Flu: -8-,: J"':e.-,,=
~yre'"'e
6e~::~c)a~:--a:e-~
n,y-se-e
6e~=:~:;I._:-=-:-~-e
6e".z::.;' .~:'o-:'~-~
6e"'.z::~o;;,:-e-!:
I n:e-: : -: , , . 3. : =: = . .. ~...-=
6e~:::;.",: ':f-,.!-~
~e-::::::':~:- ':::
...
A. p'.a'::-:
Seta'S-:
Ce.:,,':-:
Co-rc-;-:
t-e::a:-.:-
J.,.=-~r'"
re;:a:-,:- :::. :=
( - . -.:,,- ~ ;
E-.::s.. 'c. .
C:e::-:-
'."":::
En::- i r":
En:J:s.;l fa-. n
".':' I . :.:..
~e:r:>.,.:;. ::c
En:- i -. (e: :-e
Atp"a':"'.:-=c:~~
G8:T.a' C- .: -:::E:-.e
TCJ;a;)"e-,~
9.:: 1" e:. 112 Yes
6.C: 1,,3: 112 Yes
6.:: 1..3C 1/Z Yes
O.:Z No
OIZ No
OIZ No
0/2 No
0/2 lio
0/2 No
DIZ No
OIZ No
OIZ No
0/2 1110
C/2 1110
0/2 "'0
cn "'0
0/2 1110
0/2 I/o
0:2 IIIc
C '2
0/2
0/2
C:2
0/2
Co2
G/2
(,:2
O/Z
OIZ
0/2
0/2
OIZ
D/Z
DIZ
O/Z
OIZ
CIZ
No
I/o
I/O
No
110
1110
/lie
110
110
1110
"'0
'No
1110
"'0
1110
1110
"'0
."'0
POOR QUAl\TY
-------
T~5_E c-7 (contin~ed)
S~~,e'Y S:e:'s:ics fc~ Selectee S~'face ~a:er Sam:les
All "c;a:;o~s: Teol le, 5'00' a~: Easte~n wetland
~,a-:c :: - ~;E: G~c~~=.ster Study
J.s'" ;a~:, ~assa::~~setts
Compound
Me.), ii-,..."-,
(ug.' l)
Ar i t~.'''et i c 1/
Mean
(ug/l)
Frequency
of
Detection
Contaminants
of Concern
Pestic;des'P:S
(C:;"":~;I"'\.Je=)
Aroclor-1016
Aroclor-1221
Aroclor-123Z
Aroc~or-12~2
Aroclor-1Z"S
Aeo;10~-125~
Aroclo'-~2c:
0/2
0/2
0/2
0/2
0/2
0/2
0/2
No
No
No
No
No
110
110
J!"I~"'==-;:S
A l.r,i n~,",
A"',t i-,c-',
Arse-'c
5a~i~-
6e~.,~~;..;-
Ca:l"" ...-
C a: c ; ~-
C~'c-;--
52:
3.5
.., -..
2/2
0/2
0/2
0/2
0/2
0/2
2/2
2/2
2/2
2/2
2/2
2/2
2/2
1/2
2..2
1/2
110
No
110
110
110
110
110
Yes
Yes
110
Yes
110
Yes
110
110
1110
--
,:: , . ..-
35
3:
:. ,....
CCj:~-"
--
Irc,",
Lee::;
Ma-;.::-'::,~
~e"c_",
. - ~..
- -
'-
-
. . -
t-a'::i:e-.
S::' .-
- -
'-
t - , ~ : :
... ,"..
Va-,o=: ...-
23
"'::e~:
11
~:: :f:.;-=:~:
~-'t'-e:': .~=-;
:'''C, ...:,
..... -...-
..;5"-; :-e-'-:=..
:::=:e::;:""'
: :,..; t s
fC" n:-.oe:e:: sa~;.e~.
POOR QU!\L\1't'
-------
course of a lifetime and they reflect a daily exposure level that is likely
to. be without an appreciable risk of an adverse health effect. RfDs are
derived from epidemiological or animal studies and incorporate uncertainty
factors to help ensure that adverse health effects will not occur. The
hazard quotient is often expressed as a single value (e.g. 0.3) indicating
the ratio ~f the stated exposure as defined to the refer~nce dose value (in
this example, the exposure as characterized is approximately one third of
an acceptable exposure level for the given compound). The hazard quotient
is only considered additive for compounds that have the same or similar
toxic endpoints (for example: the hazard quotient for a compound known to
produce liver damage should not be added to a second whose toxic endpoint
is kidney damage). The resulting sum is referred to as the hazard index.
Table 6-8 summarizes total carcinogenic risks for downgradient areas for
all pathways, while Table 6-9 summarizes the total non-carcinogenic risk
for downgradient areas for all pathways considered. Tables 6-1 through 6-6
of the Risk Assessment summarize the risks associated with the major
contaminants of concern.
This section summarizes the calculated carcinogenic and non-carcinogenic
risk for various pathways, describes which contaminants of concern
contribute the most to the calculated risk, and compares the calculated
risk to EPA' s target carcinogenic risk range of 10." to 10.6 and discuss
non-carcinogenic hazard index as it relates to the value where adverse non-
carcinogenic effects are not expected (HI
-------
EKPOSURE AREA
MEDIUM
ROUTE OF
EKPOSURE
MOST PROBABLE
SCEIiARIO
1988 1990
REALISTIC WORST CASE
SCENARIO
19.88 1990
D~NuRADIEIi~ AREA
GROUNDWATER,
DRINKING WATER
D~NGRADIENT AREA
GROUNDWATER,
SH~ERING
DOWN~RA'!EN~ AREA
GROUN:JOIA TER ,
WAS,;:NG
DOWN~RA:;EN~ AREA
GR:JuN:~ATER ,
BASE~EN: SEE~A~E
DOWN~RA:;EN' AREA
GRJ..;N:..ATER,
BASEMEN~ SEEPAGE
TRO"LEY BI1:>OI(
SUR~A:E WATER
EAS~ERN WET.AN:
SJRFA:E \lATER
EASTERN \lET.AN:
SE::MEN~
TCTA. S;~E CAN::- .:SI(
N:"ES:
TABLE 6-8
TOTA~
CARCINOGENIC RISI( FOR D~N~RAOIENT
FOR ALL PATHWAYS
NYANZA II GROUN:JWATER STUDY
ASHLAN', MASSACHUSETTS
AREAS
IIjGESTION 2.5E-02 1.3E -01. 5.5E-02 1.3E.01
IIjHALATION 2.8E'03 8.2E-0l0 1.loE'02 3.5E-03
DERMA~ 7.9E-05 3.loE-0/'. 2.6E-Olo 3.1E-Olo
DERMA. AN;) 5.8E-06 6.7E-07 1. 1E - 05 3./'E-06
!IjGESiION
I NHA"A TI ON 3.0E.05 2.I.E-05 1.2E-Olo 1.0E'Olo
DERMA. AN: 2..6E-09 (2) (1) (1)
INGESTION
OERMA~ AN: 1. 1E-07 (2) (1) (1)
INGEST!:JN
DER~A~ AN: ,. 7E .06 (2) 1. 3E - OS (1)
IN:':STIQN
2.8E'C2 1 .3E .01 6.9E-02 1.3E'01
(1) N:: a~~: 'ca~:e be:a~se o~~, a s;n;~e.sa~le .as taKen.
(2) He s~'fa:e .a:er 0" seoimen: sa~tes .ere cotlec:ed d~rin; 199C.
The"e'c'e, t~is pat~.ay .as no: evaluatec.
. Due to the data t"ea:ment method for ave-a;in; non-detected
vat....es, the. caic...:a:ec most probable case risks (ApPendix E>
sli9rt~Y exce~s the calculated .orst case risK. The most
probable case risk nas, tnerefore, been set equal to tne .orst
case risK.
POOR QUALITY
-------
EXPOSURE AREA
MEDIUM
TABLE 6-9
TOTAL NO~:ARCIN~GE~IC RISK FOR DOWNGRADIENT
AREAS FOR ALL PATH~AYS
NYA~ZA :: GR~NJ~ArER STUDY
ASH.AN~, MASSACHUSETTS
ROUTE OF
EXPOS;,).E
MOST PROBABLE
SCENARIO
1988 1990
MOST PROBABLE
ORGAN-SPECIFIC HAZARD
INDICES EXCEEDING 1.0
1988 1990
REALISTIC WORST CASE
SCENARIO
1988 1990
DOWNGRAJIENT AREA
DOWNGRADIENT AREA
DOWNGRADIEN, AREA
DO~~GRA~!E~; AREA
D~~~~I!A~JE~, AREA
TI!:JLLEY B.:>c)(
EASTEI!~ WETLA~:::
EASTER~ IIE...A~~
GI!:JUN:::~ATEI! ,
DRINKING WATER
CROUNDWAT EI! ,
SHOWERING
CROUNDWA,ER,
WASHING
GROUNJ"'A ,EI!,
BASEME~: SEE~A~E
GI!:)U~:::ioIA,EI!,
BASEME~: SEEPAGE
SUI!-A:E WAHl!
SURFA:E "'ATEI!
SE:;ME~:
INGESTION 2.2E+02 5.6£+01 8,L,IC,U (1) B,L,K,U 5.6E+03 1.1E+03
I NHALAr I ON 1.1E+02 1.2E+01 l,IC,B L,IC,B 5.2E+02 1.8E+02
DERMA.. 1..7E-01 1.6E-01 1.0E+01 2.1E+00
II;HA.Ar IO~ 3.1£ .D1 1.6E'01 2.8E+00 6.8E-01
DEI!~A~ AN~ 9.2E-03 1..7E-03 1. 7E -01 1.9E-02
II.GE ST I O~
DERMA~ A~:; 1 .5f ,03 (2) (3) (2)
INGES: ;:J~
DER~A~ A~:; 2 .9E . 03 (2) (3) (2)
I ~GEST I O~
DERloIl,. A~~ 1. 9E . C i (2) 3.5E-01 (2)
I t.GE S,: ~~
3.3E-~2 6.ge-01 6.1E.03 1.3E.03
'T:~A.. RiS...
hc:es:
(1) Orga~ syste~ abc-e';at;~~s:
L = Live", U = U~e':ne=
(2) ~~ s~rface .ate- or sec'me~t
B = Blooc, B~ = Boo, we;g~t Effects, C = Centra~ Nervous System, K = Kidney,
sa~;es ccllected d_-i~g 199:.
POOR QUALITY
-------
1990 data, the corresponding Hazard Indices are approximately 1100 and 56,
respectively. In both data sets, the vast majority of the Hazard Index
value is due to presence of nitrobenzene, which is present at
concentrations up to 94 mg/l in groundwater in the downgradient area. Both
the worst case and most probable Hazard Indices for inhalation of
groundwater contaminants while showering from either the 1988 or 1990 dat
also exceeded 1.0 for several target endpoints indicating a potential for
adverse non-carcinogenic effects.
Groundwater exposure could also occur as a result of groundwater migrating
into residential basements in the downgradient area. Risks were estimated
for this pathway using contaminant concentrations detected in shallow
monitoring wells during both 1988 and 1990 investigations. The
carcinogenic risks predicted for breathing volatilized contaminants from
basement seepage calculated from the 1988 data were within qSEPA's target
range for both the most probable and the realistic worst scenarios (3.0 x
10-5 and 1. 2 x 10'4, respectively). The carcinogenic risks due to dermal
contact and ingestion of sump water were also within the USEPA target
range. None of the organ specific non-carcinogenic hazard indices
predicted for the inhalation of volatile contaminants in basement sumps
exceeded a HI=1.0 indicating that the potential for adverse non-
carcinogenic effects is unlikely. The Hazard Indices associated with
dermal and ingestion exposure of sump water were well below 1.0.
The risks predicted for exposure to basement seepage cal~ulated from the
1990 data are similar although sli~htly lower in magnitude to those
calculated from the 1988 data. Realistic worst case and most probable case
cancer risks associated with the inhalation pathway are both within the
USEPA target limits (1. Ox10-1, and 2. 4X10'5 , respectively). Risks associated
with dermal contact and ingestion exposures are 3.4x10-6 for the worst case
scenario and 6.7x10-7 for the most probable case scenario. Exposures to
groundwater contaminants in seepage by both routes are associated with
Hazard 7.ndices which approach but do not exceed 1.0.
Former Vault and Hill Areas - carcinogenic risks posed by the ingestion of
groundwater from both of these locations would greatly exceed the USEPA
target cancer risk range for both the most probable and realistic worst
case scenarios. Similarly, the hazard index posed by the ingestion of
groundwater from these areas non-carcinogenic also exceeded the USEPA
target hazard index of 1.0.
2.
Surface Water Risk Characterization.
Surface water exposure was assessed at Trolley Brook and the eastern
wetland based a limited number of samples. The carcinogenic and non-
carcinogenic risks of exposure through dermal contact and ingestion were
found to be within or below acceptable. A comprehensive sampling and risk
characterization effort of the surface water at the site being completed as
part of Operable Unit 3.
3.
Sediment Risk Characterization.
Sediment exposure was assessed in the eastern wetland based on a limited
number of samples. Non-carcinogenic risks were below 1.0 indicating that
the potential for adverse non-carcinogenic health effects is small. Cancer
risks associated with exposures to eastern wetland sediments were within
-------
EPA's target risk range, at 1.3xlO-s. A comprehensive sampling and risk
characterization effort of the sediments at the site is being completed as
part of Operable Unit 3.
C.
uncertainties in Estimating Risk
It should be emphasized that the risk estimates in this assessment are
based on numerous assumptions, each having uncertainty associated with it.
Several types of uncertainties should be considered in any risk evaluation:
o
uncertainties associated with identifying contaminants of concern
and estimating exposure concentrations
o
uncertainties associated with estimating the frequency, duration,
and magnitude of exposure
o
uncertainties in the models used to characterize risks
o
uncertainties in estimating carcinogenic potency factors and/or
non-carcinogenic measures of toxicity (e.g., RfDs)
A complete discussion of these uncertainties is located in Section 6 of the
Risk Assessment. .
D.
Ecological Assessment
An Ecological Assessment of the groundwater contaminants effect on the
environment was performed as a component of the Risk Assessment (Section 7)
based on a limited number of surface water sampling. Final assessment of
the Site's overall effect on surface waterbodies and their associated
ecosystems will be performed as part of the Operable Unit 3 studies now
under way.
E.
Conclusion
Actual or threatened releases of hazardous substances to groundwater, if
not addressed by implementing the response action selected in this ROD, may
present an imminent and substantial endangerment to public health, welfare,
or. the environment. Risks due to groundwater releases are dealt with in
this Record of Decision.
,
-------
VII. DEVELOPKENT AND SCREENING OF ALTERNATIVES
A. statutory Requirements/Response Objectives
Under its legal 'authorities, EPA's primary responsibility at Superfund
sites is to undertake remedial actions that are protective of human health
and the environment. In addition, Section 121 of CERCLA establishes
several other statutory requirements and preferences, including: a
requirement that EPA's remedial action, when complete, must comply with all
federal and more stringent state environmental standards, requirements,
criteria or limitations, unless a waiver is invoked: a requirement that EPA
select a remedial action that is cost-effective and that utilizes permanent
solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable: and a preference for
remedies in which treatment which permanently and 'significantly reduces the
volume, toxicity or mobility of the hazardous substances is a principal
element over remedies not involving such treatment. Response alternatives
were developed to be consistent with these Congressional mandates.
Based on preliminary information relating to types of contaminants,
environmental media of concern, and potential exposure pathways, remedial
action objectives were developed in the Feasibility Study to aid in the
development and screening of alternatives. These remedial action
objectives were developed to mitigate existing and future potential threats
to public health and the environment. These response objectives were:
1.
Reduce migration of contaminants in groundwater.
2.
Reduce risks to human health associated with potential future
consumption and direct contact with groundwater.
Reduce risks from present and potential future inhalation of
evaporated groundwater contaminants.
3.
4 .
Limit degradation of the Sudbury River and wetlands due to the
natural discharge of contaminated groundwater.
5.
Comply with state and federal applicable, relevant and
appropriate requirements (ARARs) , including drinking water
standards.
These objectives were developed for final remedial actions. The interim
actions described in the Proposed Plan and in this Record of Decision are
designed as interim steps toward reaching these objectives.
B. Technoloqy and Alternative Development and Screeninq
CERCLA and the NCP set forth the process by which remedial actions are
evaluated and selected. In accordance with these requirements, a range of
alternatives were developed for the site.
The RI/FS developed alternatives that involve little or no treatment but
provide protection through engineering or institutional controls. The
focus of Operable unit 1 and the vault removal was on source control,
therefore, the emphasis of this action is concentrated on management of
migration. '
-------
Remedia:ion
Alte~native
RA-'
RA-2
RA-)
RA-/'
!IA.S
Description
Minimal/~o Action
Site Area
Extraction
Downgradient
Management of
Migration
Site Area
Extraction
al"ld Do,,"'gradi e~,:
Management of
Mig~ation
Act i ve
Pl..lT\e-..ide
Extract;o~
TABLE 7-'
~YA~ZA GR~~~~ATER
REME~lAl ALTER~ATJVES
Extraction
EC-': ~atural
Flushing
EC-2: Extraction
we II s and
interceptor trench
at Site area only.
EC-): Downgradient
wells only
EC-/': Site area
al"ld do..ngradient
..ell s and
interceptor trench
EC'S: 'Site area
al"ld do,,"'gradient
wells thrOU9~out
the pl~ ano
interceptor trench
Treatment
No Treatment
TC-): ,Metals
precipita~ion with
filtration and air
stripping/ carbon
8dsorption.
TC-): Metals
precipitation with
filtration and air
stripping/carbon
adsorption
TC-): Meuls
precipitation with
filtration and air
stripping/carbon
adsorption
TC-): Metals
precipitation with
filtration and air
stripping/carbon
adsorption
Effluent Disposal
Not Appl icable
To Sudbury River
To Sudbury River
To Sudbury River
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With respect. to ground water response action, the ~I/FS developed a limited
number of remedial alternatives that attain site specific remediation
levels within different time frames using different techno~ogies; and a no
action alternative.
As discussed in Chapter 4 of the Feasibility Study, the RI/FS identified,
assessed and screened technologies based on implementability,
effectiveness, and cost. These technologies were combined management .of
migration (MM) alternatives. Chapter 5 of the Feasibility Study presented
the remedial alternatives developed by combining the technologies
identified in the previous screening process in the categories identified
in Section 300.430(e) (3) of the NCP. The purpose of the initial screening
was to narrow the number of potential remedial actions for further detailed"
analysis while preserving a range of options. Each alternative was then
evaluated and screened in Chapter 6 of the Feasibility Study.
In summary, of the 1 limited action alternative and the 4
of migration remedial alternatives screened in Chapter 5,
retained for detailed analysis. Table 7-1 identifies the
were retained through the detailed analysis process.
active management
all 5 were
alternatives that
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VIII.
DESCRIPTION OF ALTERNATIVES
The alternatives described here are all interim remedies. The reasons for
EPA's decision to utilize an interim remedy are spelled out in Section X of
this ROD.
u
This Section provides a narrative summary of each alternative evaluated.
Management of migration alternatives address contaminants that have
migrated from the original source of contamination. At the Nyanza Chemical
Waste Dump Site, contaminants have migrated from Megunko Hill, the vault,
and other possible source areas towards downgradient areas, and away from
the presumed ~ource areas.
The alternatives evaluated include a minimal action alternative eRA-I) as
well as a series of alternative management of migration collection schemes
(RA-2, RA-3, RA-4, RA:-S). A "true" no-action alternative was not included
because it would not have been protective, and therefore would not have met
the thres~old criteria of the CERCLA statute.
The interim alternatives discussed here are identical to the long-term
alternatives discussed in the FS, except that their comparison is based on
a S-yearoperational period, rather than the 30-year time frame used for
cost purposes in the FS. The cost estimates are documented in the
administrative record.
Each of these alternatives is described briefly below, along with a
discussion of how each would function as an interim remedy. A more
detailed description of each alternative can be found in Section 6 of the
FS report. .
Alternative RA-l: Minimal/No Action: The FS evaluated this alternative in
. detail to serve as a baseline for comparison with other remedial
alternatives under consideration. Under this alternative, no treatment or
containment of groundwater contamination would occur. The objectives of
this alternative are to restrict public access and potential exposure to
Site contamination, prohibit use of contaminated groundwater, and evaluate
Site conditions and contaminant migration periodically during the interim
period. These objectives would be accomplished using Site access control
~easures and institutional controls to limit exposure to contaminants and
installation of wells and long-term environmental monitoring. Fencing and
signs would be readily installed by vendors in the area. Environmental
monitoring would also be conducted easily by several vendors.
Institutional controls in the form of deed and well permit restrictions may
require cooperation from local and state authorities.
Estimated
Estimated
Estimated
Estimated
$721,000
Estimated
Time for Design and Construction: one year
Time of Operation, interim alternative: 5 years
Capital Cost: $320,000
Operation and Maintenance Costs (5 years, present worth) :
Total Cost (present worth): $l,O~l,OOO
Alternative
Boundary of
effluent to
alternative
RA-2: Management of Migration with extraction at the Northern
the Site; treatment of collected groundwater; discharge of
the Sudbury River: This alternative is the selected
and is discussed in Section X, entitled "The Selected Remedy".
-------
Alternative RA-3: Management of Migration with extraction to the north and
north-east of the Site; treatment of collected groundwater; discharge of
effluent to the Sudbury River: This remedial alternative involves
contaminated groundwater extraction in the portion of the plume to the
north and north-east of the Site; treatment of the groundwater; and.
discharge of treated groundwater into the Sudbury River. The treatment
process is the same one as is described under EPA's selected alternative.
This alternative also includes the Site control features described for RA-
1. The objective of this alternative is to prevent the contaminants from
expanding beyond current limits of the plume and thereby prevent the
discharge of contaminants to the Sudbury River. Unlike RA-2, this
alternative would not directly remediate the source area of the
contaminated groundwater, thus allowing potentially high levels of
contamination to migrate by natural processes tothe'extraction wells to
the north and north-east of the Site before being removed from the aquifer.
As an interim remedy, this alternative would permit the collection of some
operational data, but it would also allow the continued migration of
groundwater contaminants from the site.
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $3,87Q,000
Estimated Operation and Maintenance Costs (5 years, present worth):
$1,820,000
Estimated Total Cost (present worth): $5,690,000
Alternative RA-4: Management of Migration with extraction both at the
northern boundary of the Site and to the north-east of the Site; treatment
of the collected groundwater; discharge of effluent to the Sudbury River:
This alternative extracts highly contaminated source area groundwater by
combining the extraction components of the selected Alternative RA-2 with
those of Alternative RA-3. The collected groundwater would undergo
treatment to remove contaminants as described in the selected Alternative
RA-2. Following treatment, the water would be discharged to the Sudbury
River. This alternative would include the Site control features described
for Alternative RA-1. The objective of this alternative is to prevent the
contaminated groundwater from expanding beyond its current boundaries and
ultimately into the Sudbury River. This alternative would also extract the
most highly contaminated groundwater to prevent increases in contamination
to the north and east of the Site. RA~4 would require much more disruption
to the community surrounding the Site than the selected alternative, while
capturing contaminants over a larger area.
As an interim remedy, this alternative would permit the collection of
operational data, while reducing the migration of contaminants throughout
the plume.
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $6,050,000
Estimated Operation and Main~enance Costs (5 years, present worth):
$3,140,000
Estimated Total Cost (present worth): $9,190,000
Alternative RA-S: Active Plume-Wide Extraction; treatment of the collected
groundwater; discharge of effluent to the Sudbury River: This alternative
is a comprehensive plume-wide alternative that differs from the others
-------
because it involves extraction of contaminated water at many locations
throughout the plume. It also includes groundwater treatment as described
for the selected Alternative RA-2, followed by discharge of the treated'
water into the Sudbury River. Alternative RA-5 would also include the site
control features described for Alternative RA-1. This alternative would
use numerous extraction wells to minimize the transport of contamination
through the aquifer and to minimize the time frame required to complete
treatment of the aquiferj and would prevent migration and discharge of
contaminated groundwater into the Sudbury River. Uniformly distributed
extraction wells would prevent highly contaminated groundwater from
migrating to areas of lower concentrations.
As an interim remedy, this alternative would permit the collection of
operational data, while reducing the migration of contaminants throughout
the plume.
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $6,650,000
Estimated Operation and Maintenance Costs (present worth, 5 years):
$3,430,000
Estimated Total Cost (present worth): $10,080,000
,
-------
IX.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 121(b) (1) of CERCLA presents several factors that at a minimum
EPA is required to consider in its assessment of alternatives.
Building upon these specific statutory mandates, the National
Contingency Plan articulates nine evaluation criteria to be used in
assessing the individual remedial alternatives.
A detailed analysis was performed on the alternatives as final
remedies using the nine evaluation criteria in order to select a
remedy and can be found in the FS at pages 6-10 through 6-82. The
following is a summary of the comparison of each alternative's
strength and weakness with respect to the nine evaluation criteria.
These criteria and their definitions are: .
Threshold criteria
The two threshold criteria described below must be met in order for
the alternatives to be eligible for selection in accordance with the
NCP. .
1.
Overall protection of human health and the environment
addresses whether or not a remedy provides adequate
protection and describes how risks posed through each
pathway are eliminated, reduced or controlled through
treatment, engineering controls, or institutional controls.
2 .
Compliance with Applicable or relevant and appropriate
requirements (ARARS) addresses whether or not a remedy will
meet all of the ARARs of other Federal and State
environmental la~s and/or provide grounds for invoking a
waiver.
Primary Balancinq criteria
The following five criteria are utilized to compare and evaluate the
ele~ents of one alternative to another that meet the threshold
criteria.
. 3.
5.
Long-term effectiveness and permanence addresses the
criteria that are utilized to assess alter-natives for the
long-term effectiveness and permanence they afford, along
with the degree of certainty that they will prove
successful.
4 .
Reduction of toxicity, mobility, or volume through treatment
addresses the degree to which alternatives employ recycling
or treatment that reduces toxicity, mobility, or volume,
including how treatment is used to address the principal
threats posed by the site.
Short term effectiveness addresses the period of time needed
to achieve protection and any adverse impacts on human
health and the environment that may be posed during the
construction and implementation period, until cleanup goals
are achieved. .
-------
6.
Implementability addresses the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed to implement.a particular
. option.
7.
Cost includes estimated capital and operation Maintenance
(O&M) costs, as well as present-worth costs.
Modifvina criteria
The modifying criteria are used on the final evaluation of remedial
alternatives generally after EPA has received public comment on the
RIfFS and Proposed Plan.
8.
state acceptance addresses the State's position and key
concerns related to the preferred alternative and other
alternatives, and the State's comments on ARARs or the
proposed use of waivers.
9.
community acceptance addresses the publics general response
to the alternatives described in the Proposed Plan and RIfFS
report.
Following the detailed analysis of each individual a~ternative, a
comparative analysis, focusing on the relative performance of each
alternative as a final remedy against the nine criteria, was
conducted. This comparative analysis can be found in section VI of
the Feasibility Study. .
The section below presents the nine criteria and a brief narrative
summary of the alternatives as interim remedies and their strengths
and weaknesses according to the detailed and comparative analysis.
1.
Overall Protection of Human Health and the Environment:
Each of the alternatives, viewed as five-year interim measures, would
r~duce the overall risk to human health and the environment to varying
degrees. Over a five-year period, alternative RA-l would provide the
least protection due to uncontrolled migration of existing
contamination and continued contaminated discharges into the Sudbury
River. Over a five-year period, alternatives RA-2, RA-4 and RA-5
would limit the migration of highly contaminated groundwater from the
site to areas to the north and east, thereby preventing an increase in
current potential risks in the portion of the plume to the north and
east of the Site. Alternatives RA-2 through RA-5 would. also prevent
discharge of contaminated groundwater to the River to some extent.
Over a five-year period, alternative RA-5 would provide the most
effective removal of contaminants, because wells would be placed at
many locations throughout the study area. Alternative RA-3 would be
the least effective of the active alternatives (RA-2, RA-3, RA-4, and
RA-5) because the large mass of cpntarnination found on-site would have
to migrate to the plume management wells to the north and north-east
of the Site before collection. Alternative RA-2 would remove a
significant amount of contaminants, since it deals directly with the
areas where the highest concentrations of groundwater contaminants
haVe been found and will draw contaminants from a large percentage of
the known plume area.
-------
Each of alternatives RA-2, RA-4, and RA-5, when viewed as interim
remedies, would provide similar information leading to the choice of a
final remedy. Alternative RA-3 would provide less information, since
it would not be drawing groundwater from the most contaminated area
near the vault.
2.
Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs) :
When comparing interim remedies, it is appropriate to analyze
compliance only with those laws and regulations that are applicable or
releVant and appropriate to the limited scope of the interim action.
For all groundwater that they would extract and treat, Alternatives
RA-2 through RA-5 would meet the same ARARs for the discharge of the
treated groundwater into the Sudbury River, the discharge of air, and
the disposal of sludges resulting from the treatment process. In
addition all location specific ARARs will be met. These ARARs would
be met during the interim remedial period.
3.
Long-term Effectiveness and Permanence:
Long-term effectiveness and permanence is not relevant to the
comparison among interim measures. The long-term effectiveness and
permanence of the actions will be considered in a final ROD, based in
large part on the data collected during the interim remedial period of
5 years. .
4.
Reduction of Toxicity, Mobility or Volume through Treatment:
Alternative RA-l provides no reduction in toxicity, mobility, or
volume of the contaminants in the plume except through natural
processes. As interim measures, alternatives RA-2 through RA-5 all
reduce the toxicity, mobility, and volume of organic contaminants
through groundwater extraction and treatment. Alternative RA-2
reduces the toxicity, mobility, and volume of organic compounds less
than Alternatives RA-4, and RA-5, because it treats a smaller portion
of the entire plume. However, RA-2 is superior to RA-3 with regard to
toxicity, mobility, and volume since it attempts to capture
contaminants closer to their source.
5.
Short-Term Effectiveness:
Alternative RA-l would pose the least short-term risk of adverse
impacts on human health and the environment, because it does not
include any disturbance of contaminated areas.
The short-term risks from Alternatives RA-2 through RA-5 consist of
the possibility of airborne dust emissions and volatilization of
contaminants during construction and operation of the groundwater
extraction and treatment systems. Special engineering precautions,
however, including air monitoring and contingency planning, would
minimize these risks and protect workers and area residents. There is
a very small chance that residents could be exposed to collected
groundwater through leakage in the collection network which would be
extended throughout the neighborhood under RA-3, RA-4, and RA-5.
Alternative RA-2, which would be constructed primarily in an area
zoned as industrial, would pose the least potential risk to area
residents during construction and operation of the
-------
7.
8.
9.
extraction/treatment system. .Alternative RA-5 would pose the greatest
risk, because of the numerous extraction wells that would be located
in residential areas.
6.
Implementability:
Alternative RA-l would be the most easily implemented, since it
requires no construction and would require minimal administrative
approvals, other than those relating to institutional controls. The
institutional control measures, as well as public education measures
are common to all five alternatives under consideration, and therefore
provide no basis to differentiate the alternatives in terms of
implementability. The various components of Alternatives RA-2 through
RA-5 are common elements of remedial projects that could be readily
implemented. Each would involve some coordination with local
agencies, which might include meeting with Town Boards and Department
to apprise them of planning and construction activities. Alternatives
RA-3, RA-4, and RA-5 would require the greatest degree of coordination
with local agencies, as a result of the larger area that would be
affected by these alternatives.
All the active alternatives woul~ cause some levels of interferences
with services, utilities, and existing structures. The extraction and
piping systems for Alternatives RA-3, RA-4, and RA-5 would be located
in residential and mixed use areas .and would have a greater impact on
residential and commercial activities than would RA-2. RA-2, with its
focus primarily in an industrial area, would cause the least such
disruption. construction activities associated with Alternative RA-5
would cause the greatest such disruption because of its many
extraction locations.
Cost:
The capital, operation and maintenance, and total cost for each
alternative for the 5-year interim period is provided as part of the
preceding "Description of Alternatives" section.
Construction and operation of the selected alternative will provide
data on costs that can be used to assess the costs of the alternatives
considered in the final ROD for this operable unit.
state Acceptance:
The Commonwealth of Massachusetts has indicated its concurrence with
the selected remedy via its concurrence letter (Appendix II).
Community Acceptance:
Based on the written and oral co~~ents received during the recent
comment period, there is general acceptance of the selected remedy,
although some commenters requested a larger scale remedy. Response to
community comments are located in Appendix I.
-------
x.
THE SELECTED REMEDY
EPA has chosen RA-2 as the selected alternative. RA-2 is an interim remedy
whose goals are to manage the migration of contaminants, to treat the
highest levels of groundwater contamination in the plume, and to collect
operationa~ groundwater cleanup data. Based on the information collected
during operation of the interim remedy, EPA will then prepare a final ROD,
which will specify the ultimate goals, remedy and the anticipated time
frame for remediation. The final ROD will also include the groundwater
target cleanup levels or, if the evidence indicates that it is
impracticable to achieve all such target cleanup levels, waivers of ARARs.
EPA's selection of this interim remedy is consistent with current EPA
guidance for groundwater remediati.on at Superfund sites, the requirements
of CERCLA, and to the extent practicable, the National Contingency Plan.
Specifically, evaluation of currently operating groundwater remedies at
other Superfund sites has shown that extraction systems are effective in
containing plumes, thus preventing further migration of contaminants, and
in achieving significant mass removal of contaminants from groundwater.
Many factors, including the hydrogeologic characteristics of the aquifer
and the physical and chemical properties of the contaminants, may limit the
effectiveness of the selected remedy to reach drinking water standards.
This will be evaluated during the interim remedy's operational period.
Based on these findings, the EPA Office of Solid Waste and Emergency
Response has recommended the following approaches to developing and
implementing groundwater response actions at Superfund sites:- 1)
initiation of an early response action to reduce further migration of
contaminants; 2). incorporation of flexibility in the selected alternative
to allow for changes in the remedy; and 3) collection of data to better
assess the movement of conta~ination and the effectiveness of the
extraction system. EPA has followed these recommendations in developing
the selected interim remedy for Operable Unit II.
EPA's selected alternative (RA-2) will allow for remediation of the most
highly contaminated areas of the groundwater, immediately reducing
potential risks in this area and preventing migration into less
contaminated areas. The alternative will also provide some protection to
the Sudbury River by limiting discharge of contaminated groundwater to the
river north of the Site. (The full i~pact of groundwater discharge on the
river is one of the subjects of Operable Unit III, and is not within the
scope of Operable Unit II.) The selected alternative is more protective
and would provide more reduction of toxicity, mobility or volume of the
contamination than the no-action alternative, RA-l. Finally, because it
anticipates that extraction and treatment will take place primarily in an
industrial area, the selected alternative will cause the least disruption
to residential areas in comparison to alternatives RA-3, RA-4 and RA-5.
In the portion of the study area to the north and east of the Site,
. institutional controls will provide protection from exposure to
contaminants that would not be remediated as part of the interim remedy.
Levels of contamination in this area are expected to be reduced gradually
over time as the highly contaminated portion of the plume is remediated.
Wells at the eastern and southern boundary of the plume will be monitored
to assess any further migration of contaminants. The final ROD will
address the potential need for groundwater remediation in the plume to the
east of the Site. .
-------
o
b
In summary, the selected alternative will best serve the purposes of an
interim remedy by reducing further migration of contaminants, providing
flexibility, and allowing the collection of data to test the .effectiveness
of the extraction system. At the same time, the selected alternative would
achieve the best balance among criteria used by EPA to evaluate the'
alternatives. The selected alternative is more cost-effective and readily
implementable than the other alternatives, has fewer short-term effects,
and achieves all ARARs applicable to its limited scope.
A.
Cleanup Levels
. As an interim step to meeting the remedial response objectives outlined in
Section VII., the selected remedy will extract and treat groundwater from
the northern border of the Site, including the most. highly contaminated
portion of the plume. The FS indicates that the time required to attain
drinking water standards in groundwater could range from decades to
centuries, even using the alternative employing the most extraction wells.
Because of the uncertainty as to when and whether active remediation will
achieve groundwater-quality ARARs, EPA has selected a five-year interim
remedy. During operation of the 5-year interim remedy, EPA will assess the
performance of the remedy in achieving progress toward the cleanup
objectives. Based on this assessment, EPA will issue a final ROD,
identifying the target groundwater cleanup levels that will comply with
ARARs and evaluate whether a remedy capable of attaining those cleanup
levels could be implemented. Thus, EPA will not identify the target
groundwater cleanup goals at this time. This interim remedy, including the
groundwater treatment plant, will continue to operate at least until the
final ROD has been signed.
B.
Description of Remedial Components
~
EPA's selected interim alternative (RA-2) to remediate contaminated
groundwater consists of groundwater extraction wells at the northern border
of the Site; treatment of the collected groundwater; and discharge of the
treated effluent to the Sudbury River. The alternative may also employ a
collection trench at the northern border of the cap now under construction
on Megunko Hill, depending on whether further study indicates that such a
trench is feasible and necessary. Figure 10-1 shows the approximate
location of the proposed extraction wells and/or trenches. It is
~nticipated currently that the discharge will be made on-site, although the
cost estimate for RA-2 includes the installation of a pipe to the river if
it is found to be necessary during design. The selected alternative will
operate for a period of five years, during which time environmental.
monitoring will be performed. After this time period, EPA will evaluate
the performance of the extraction and treatment systems in a final RI/FS
and make a final remedy selection in a subsequent final ROD for this
Operable Unit. The system will continue to operate at least until the
final ROD has been signed. .
The selected remedy will reduce contaminant migration in the direction of
groundwater flow (including into the Sudbury River) by cleaning up the most
highly contaminated area and sources of the contamination. This selected
remedial alternative will not remediate groundwater contamination in the
eastern part of the plume in downtown Ashland during the interim remedial
period. By extracting groundwater near th~ northern boundary of the Site,
however, the selected alternative will prevent contaminant concentrations
-------
within the eastern portion of the plume from increasing, thereby preventing
current potential risks from increasing in this area.
The selected remedy also includes the following elements: 1) using
institutional and access controls to limit exposure to contaminants.
Institutional controls in the form of deed and well permit restrictions
which may require cooperation from local and state authorities are exampl~~
of institutional controls which could be implemented. The deed.
. restrictions could be used to detail restrictions and safeguards on future
excavation activities on the Site. The well permit restrictions could be
imposed by the Town of Ashland to restrict the ability of land-owners to
install new wells in the area of known groundwater contamination; 2)
Further testing in the eastern portion of the plume to help determine the
feasibility of cleaning up groundwater in this area in the future; 3)
Installing additional deep bedrock wells to more fully define the depths
and locations to which contaminants may have migrated; 4) Continuing
monitoring of existing residential and monitoring wells and limited surface
water testing to track any further progress of the plume; 5) Inspecting the
Megunko Road waterline to determine whether any deterioration has been
caused by Site contamination; and 6) Pre-design studies to aid in the
design of the selected interim remedy.
~
The construction of the groundwater treatment facility will require
approximately one acre of land, a system of collection wells and/or
trenches to collect the contaminated groundwater, and a piping network to
transport groundwater to the treatment facility. This alternative would
require less disruption to the nearby residential community than the other
alternatives considered since the collection system would be located mainly
on industrially zoned land. .
The system will be designed to be flexible in order to accommodate
potential changes in operation. This will allow for such operating
techniques as pulsed pumping, or extraction well relocation based on
operating experience. In addition, the treatment system will be designed
so that it may be expanded if a subsequent decision to enlarge the
collection system is made.
For the. purpose of estimating the cost of the various remedial alternatives
the FS analyzed, as a representative technology, a groundwater treatment
plant consisting of precipitation, air stripping, and carbon adsorp~ion
treatment. EPA, in consultation with the Commonwealth of Massachusetts,
will select the actual technology to be used in the interim remedy from
among the follbwing technologies: the air stripping t~chnology outlined
below, or ultraviolet-oxidation or biological treatment units in the place
of the air-stripping process as part of a comprehensive treatment system.
A predesign cost effectiveness evaluation of the three technologies will be
conducted in order to select the two technologies for pilot testing. The
final selection of a groundwater treatment technology will be based on data
collected during the predesign pilot studies.
Figure 10-2 illustrates how the air stripping treatment process could
remove contaminants from the aquifer and treat the collected water to
levels that are safe for discharge. Groundwater extracted from the aquifer
would undergo precipitation, a chemical treatment method that converts
dissolved metals to an insoluble form and allows suspended solids to
accumulate and settle. After precipitation, water would pass through a
sand or cartridge filter to remove suspended solids and would then enter an
air stripper unit. Air stripping is an aeration process that reduces
-------
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LEGEND
FIGURE 10-1
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, GROUNDWATER EXTRACTION WELLS
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-------
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, , , , , , , , , , , , , , , , , , , , ,
, , , , , , , , , , , , , , , , , , , , , , , /
FIGURE 10-2.
GROUNDWATER EXTRACTION AND REPRESENTATIVE TREATMENT SYSTEM
(
,..,
(
-------
concentrations of VOCs and some SVOCs by changing contaminants in the
groundwater into a gaseous form. A final treatment process, carbon
adsorption, would remove any remaining organics "in the water to levels
acceptable by federal and state requirements for discharge to the Sudbury
River. Carbon adsorption removes organic compounds by filtering an~
adsorbing dissolved and suspended contaminants in the treated groundwater.
Air emissions would also be controlled through the use of carbon
adsorption.
o
u
Estimated Time for Design and Construction: 3 years
Estimated Time of operation: 5 years
Estimated Capital Cost: $5,260,000
Estimated Operation and Maintenance Cost (5 years, present worth):
$2,180,000
Estimated Total Cost (present worth): $7,440,000
To the extent required by law, EPA will review the Site at least once every
five years after the initiation of remedial action at the Site as long as
any hazardous substances, pollutants or contaminants remain at the Site to
assure that the remedial action continues to protect human health and the
environment. EPA will also evaluate risk posed by the Site at the
completion of the remedial action (i.e., before the Site is proposed for
deletion from the NPL).
-------
XI.
STATUTORY DETERMINATIONS
The remedial action selected for implementation at the Nyanza Chemical
Waste Dump site is consistent with CERCLA and, to the extent practicable,
the NCP. The selected remedy is protective of human health and the
environment during the interim operational period, attains ARARs which
apply to this' limited scope action, and is cost effective. The selected
remedy, which is not designed or expected to be final, also satisfies the
statutory preference for treatment which permanently and significantly
reduces the mobility, toxicity or volume of hazardous substances as a
principal element. The selected remedy represents the best balance of
tradeoffs among alternatives with respect to the pertinent criteria in
light of the limited scope of this action. Additionally, the selected
remedy utilizes alternate treatment technologies or resource recovery
technologies to the maximum extent practicable. .
"
A.
The Selected Remedy is Protective of Human Health and the Environment
The selected remedy, viewed as a five-year interim measure, would reduce
the overall risk to human health and the environment. Over a five-year
period, the remedy would limit the migration of highly contaminated'
groundwater from the site to areas to the north and east, thereby.
preventing an increase in current potential risks in the portion of the
plume to the north and east of the site. It would also prevent discharge
of contaminated groundwater to the Sudbury River to some extent. The
selected remedy would remove a significant amount of contaminants, since it
deals directly with the areas where the highest concentrations of
groundwater contaminants have been found and will draw contaminants from a
large percentage of the known plume area.
Finally, implementation of the selected remedy will 'not pose unacceptable
short-term risks or cross-media impacts because controls will be placed on
possible emissions from the treatment facility to be constructed, most of
the remedy will be constructed in a non-residential area, and construction
controls will limit any fugitive emissions.
B.
The Selected Remedy Attains ARARs
This remedy will attain all applicable or relevant and appropriate federal
and state requirements that apply to this limited scope interim action.
Generally, ARARs for the selected interim remedial action are a subset of
those found in Tabl~s 3-1, 3-2, and 3-4 of the Feasibility Study. Because
the Feasibility Study considered permanent remedial alternatives and the
remedy selected is a interim remedy, some of the ARARs outlined in the.FS
do not apply to this limited interim action. The ARARs that do apply to
this interim action are listed in Tables 11-1, 11-2, and 11-3 and are
discussed below.
When considering interim remedies, it is appropriate to analyze compliance
only with those laws and regulations that are applicable or relevant and
appropriate to the limited sCOPe of the interim action. For instance, for
groundwater that is extracted and treated, the selected remedy would meet
ARARs for the discharge of the treated groundwater into the Sudbury River,
the discharge of air, and the disposal of sludges resulting from the
treatment process.
-------
MEDIUM/AUTHORITY
,
REQUIREMENT
TABLE 11 - 1
CHEMICAL'SPECIFIC ARARS
NYANlA CHEMICAL SITE
ASHLAND, MASSACHUSETTS
STATUS
c
c
REQUIREMENT SYNOPSIS
Surface lIater
State Regulatory Requirements
federal Criteria, Advisories,
and Guidance
Air
federal Regulatory Requirements
State Regulatory Rrquiremcnts
Massachusetts Criteria,
Advisories, and Guidance
DEP - Surface lIater Qual ity
Standards (314 fMR 4.00)
Clean lIater Act (CIIA) - Ambient
lIater Quality Criteria (AI/QC)
(Sect ion 304)
CAA. National Ambient Air QUiltity
Standards (NAAQS) . (40 CfR ~O)
DfP - Air Quality Air Pollut ion
(310 CMR 6.00 - 8.00)
DEP - Air Pollution Control (310
CMR 7.00)
Massachusetts Guidance on
Allowable Ambient Air Levels
(AALs) - Threshold Effects
Exposure Limit (IEl)
Appl icable
Rei evant and
Appropriate
Rct evant and
Appropr. i ate
Appl icablE'
Appl icablE'
To be Considerl'd
DEP SurfacE' lIater Ouality Standards are given for
dissolvl'd oxygen, temperature increase, ph and total
coliform. There is a narrative requirement for toxi-
cants that incorporates Federal AI/QC. Through the
incorporation of the Fl'deral AI/QC, numerical criteria
exist for several of the Nyanza Site contaminants of
concern. These criteria are adoptl'd as state
standards and are subsequently usl'd in determining
effluent discharge limits (see Table 11-4)
federal AI/QC are criteria for the protection of health
and aquatic organisms which have been developed for 95
carcinogenic and noncarcinogenic compounds. AIIOC can
be used to characterize human health risks associated
with either ingestion of water and/or consumption of
aquatic organisms.
ThesE' standards were primarily devE'lopl'd to regulate
stack ilnd automobile l'missions. Standards for part-
iculate mailer will be usl'd when assessing excavation
and treatn~nt emission controls. Standards arE'
considered potE'ntially relevant and appropriate as
they were originally developl'd to control stack and
auto emissions.
Standards will be used for controlling excavation
practices and emissions from groundwater treatment
systems.
These regulations prevent air pollution from occurring
in areas where such conditions do not currently exist
and facilitate the abatement of conditions of air
pollution where and when. they do occur. All
excavation, construction, and treatment activities
will utilize Best Available Control Technology in
order to prevent contaminant transfer between other
ml'dia and air.
AALs must be consiclerl'd for any new discharges from
air pollution sources. TEls and AAls will be usl'd to
assess the basel ine subchronic and chronic human
health risks and to evaluate the public health impact
-------
MEDIUM/AUTHORITY
REQUIREMENT
STATUS
REQUIREMENT SYNOPSIS
~etland/floodplains
federal Regulatory Requirement
State Regulatory Requirements
A_i.i:
Clean Water Act (C~A)
~etlands Executive Order
(EO 11990)
(,0 CFR Part 6, Appendi x A
DEP - Wetlands Protection (310 CMR
10.00)
N~tional Ambient Air Qu~lity
Stand~l-ds «(,0 CfR Part SO)
Appl icable
To be Considered
Appl icable
Applicable
Relevant and
Appropriate
Under this requirement, no-activity that adversely
affects a wetland shall be permitted if a practicable
alternative that has less effect is available.
Under this regulation, federal agencies ere required
to minimize the destruction, loss or degradetion of
wetlands, and preserve end enhance naturel and
beneficial values of wetlands. Activities that
involve construction must include ell precticable
means of minimizing herm to wetlands. ~etlands
protection considerations must be incorporated into
the planning and decision making about remedial
al ternat ives.
Contains EPA's policy on implementing Executive Order
(EO 11990)
These regulations regulate dredging filling, altering,
or polluting inland wetlands. All work in or within
100 feet of a wetland will be evaluated for its
ability to attain regulatory perfor~1nce standards,
Including mitigation of impacted wetlands. The
selected remedy is not anticipated to involve
activities within 100 feet of a wetland.
federal agencies are required to determine if the site
is located within a nonattainment area for ozone.
Remediation of sites within nonattainment areas must
consider the ozone attainment status in designing
remediation systems.
-------
c
"
MEDIUM/AUTHORITY
REOUIREMENT
S T A JUS
REOUIREMENT SYNOPSIS
Table 11-1 (Continued)
Page 2
Ai r
F~eral Occu~'tional
Rcgulations
OSHA Threshold Limit Valucs
Appl icnbl e
Standards for controlling air quality in work place
enviro~nts. TlVs could be used for assessing
-------
'fABLE 11. 2
POTENTIAL LOCATION-SPECIFIC
NYANZA CH~ICAL SITE
AmI LAND , MA~~ACHUSETTS
MED/UN/AUT~/TY
ARARs
ItEau/UMEN'
STATUS
.Eau/ItENEN' SYNOPSIS
~tlendilioodblelni
'~rel Itetuletory Itequlre.ent
Cleen Weter Act (CVA)
Appllcllble
lieU 8nd8 hec:utf ve Order
(EO 11990)
To be Cone I dered
40 CI. Part 6, Appendi. A
ApplIcable
State Itegulatory Itequire.ente
DEP . Wetl8nd8 Protection (310 OMIt
10.00)
Appl iCable
!.!L
.atlonea AlM»lant Air QualIty
Stendard8 (40 Cllt Part 50)
.alevant and
Approprleta.
..
Under thie requir~t, no activity that edverlely
effectl a ~tland Ihall be penRitted If a prectlcable
elternative thet hel leel effect II evelleble.
Under thll reguletlon, lederal aeenclee ere required
to Mlnl.l,a the de.tructlon, loe. or degredetlon of
wetl8nde, and pre.arve and enhanca natural and
beneficia' value. of wetland.. Actlvltle. that
Involve Contructlon -t Include a\l practicable --
of Mini_hi.. harM to wetlanda. Wetlanda protection
conelderatlone -t be Incorporated Into the planning
and decl.'on ..king about remedial alternatlvel.
Contalne EPA'I policy on 1.lelllfntlng Executive Order
(EO 11990)
The.e reguletlons regulate dredgIng fillIng, altering,
or polluting inland ~tl8nd8. All work In or within
100 feet of e ~tland wIll be evaluated for Itl
ability to etteln regulatory perfOrMInCe It8nd8rd8,
Including Mitlgetlon of I~ted wetlend8. 'he
.eleeted r~ II not antlclpeted to Involve
actlvltie. within 100 feet of a ~tle~.
lederel l8encle. ere requIred to dete"'ln If the elte
Ie locted wIthin a nonattalnMent erea for orone.
1te8edlatlon of lit.. within nonattelnment erees -t
consider the ozone etteinment Itetus in designing
-------
C'
I'
STATUS
TABLE 11-3
POTENTIAL ACTION-SPECIFIC ARARS
NYANZA CHEMICAL SITE
ASHLAND, MASSACHUSETTS
OSHA - General Industry Standards
(29 CFR 1910)
OSHA - .Safety and Heal th Standards
(29 CFR 1926)
OSHA - Record keeping, Reporting,
and Related Regulations (29 CFR
1904 )
Hazardous Substance Right-to-know
(105 CMR 67) (454 CMR 21) (310 CMR
33)
DEP - Hazardous Waste Regulations,
<310 CMR 30.00)
DEP - Wetlands Protection (310 CMR
10.00)
Appl icable
Appl icable
Appl icabl e
Appl icable
Relevant and
Appropriate
Relevant and
Appropriate
All
REOUIREMENT SYNOPSIS
All
All
All
All
All
ACTlON(S)
ARARS
These regulations specify the 8-hr. time-weighted
average concentration for various organic compounds.
Training requirements for workers at hazardous waste
operations are specified in 29 CFR 9910.120-
This regulation specified the type of safety equipment
and procedures to be followed during site remediation.
This regulation outlines the record keeping and
reporting requirements for an employer under OSHA.
These regulations establish requirements to protect
health and safety of employees and community residents
through the communication of information regarding
toxic and hazardous substance.
This regulation provides a comprehensive program for
the handling, storage, generation, transportation,
treatment, use, re-use, recycling and recordkeeping
for hazardous waste.
This regulation outlines the requirements necessary to
-------
ACT ION(S)
ARARS
S T A TUS
REOUIREMENT SYNOPSIS
Table "-3 (Continued)
Page 2
Onsite ~ater Treatment and
Discharge
National Pollution Discharge
Elimination System (NPDES) (40 CFR
122 and 125)
Appl icable
Regulates the discharge of water into public surface
waters. Among other things, major requirements are:
. Use of best available technology (BAT) economi-
cally achievable is required to control toxic and
nonconventional pollutants. Use of best conven.
tional pollutant control technology (BCT) is
required to control conventional pollutants.
Technology-based limitations will be determined on
a case-by.case basis based in part on Pre-Design
Pilot Testing.
A Best Management Practices Program should be
developed and adhered to.
Applicable Federal approved State water quality
standards must be complied with. These standards
may be in addition to or more stringent than other
Federal standards under the C~A.
..
The discharge must conform to applicable water
quality requirements when the discharge affects a
state other than certifying state.
The discharge must be consistent with the require-
ments 01 a ~ater Ouality Management Plan approved
by EPA.
. Discharge limitations must be established for all
toxic pollutants that are or may be discharged at
levels greater than that which can be achieved by
technology-based standards.
. Discharge must be monitored to assure compliance.
Discharger will monitor: the mass of each
pollutant, the volume of effluent, and the
frequency of discharge and other measurements as
appropriate.
.
Approved test methods for waste constituents to be
monitored must be followed. Detailed requi rements
for analytical procedures and quality controls are
-------
ACTlON(S)
,
ARARS
STATUS
REOUIREMENT SYNOPSIS
Table 11-} (Contirued)
Page }
Onsite ~ater Treatment and
Discharge (Cont'd)
Toxic Pollutant Effluent Standards
(1,0 erR 129)
MD~PC - Massachusetts Surface
~ater Discharge Permit Progl~m
<314 CMR 3.00)
DEP - ~ater Resources Management
Program - ~ithdrawal Permit
Requirements (310 CMR 36.00)
DEP- Surface Water Ouality
Standards (314 CMR 4.00)
MDWPC - Supplemental R~irements
for Hazardous ~aste Management
facilities (311, CMR 8.00)
Rf'1 {'vant and
App' "p' ,ate
Appl icabte
Appl icable
Appl icable
ReI evant and
Appropriate
.
Permit application information must be submitted,
including a description of activities, listing of
environmental permits, etc. Onsite discharges to
surface waters are eXeq)t from procedural. NPDES
permit requirements. (Section 121 or SARA eXeq)ts
onsite CERClA activities from obtaining permits.
However, the substantive requirements of the permit
must be met). Offsite discharges would be required
to apply for and obtain an NPDES permit.
. Monitor and report results as required by permit
(minimum of at least annually).
.
Comply with additional permit conditions such as:
duty to mitigate any adverse effects of any
discharge; and proper operation and maintenance of
treatment systems.
NPOES permitting. requirements for the following
pollutants: aldrin/dieldrin, DOT, endrin, toxaphene,
benzidine, and PCBs.
Stipulates the requirements for obtaining NPDrs in
State of Massachusetts.
These regulations require registration of groundwater
or surface water withdrawals greater than 100,000
gallons per day. Design activities will make final
determination regarding the extraction flow expected.
These regulations designate the most sensitive uses
for which surface waters shell be enhanced, main-
tained, and protected; end prescribe the minimum water
quality criteria required to sustain the designated
uses. federal A~C are incorporated in determining
effluent discharge limits under the NPOES Program.
Where recommended limits are not available, site-
specific limits shell be developed.
OUtlines additional requirements for water treetment
unit, surface impoundment and POTW which treats
-------
ACTlON(S)
ARARS
~ T A JUS
REOUIREMENT SYNOPSIS
Table ,,-] (Continued)
Page I,
On~ite ~ater Treatment and
Di~charge (cont'd)
Excavation
DEP -Ai r Qual ity. Air Pollution
<310 CMR 6.00 - 7.00)
Propos~ Standards for Control of
Emissions of Volatile Organics -
S2 FR ]748 (February S. 1987)
Threshold limit Values (TlV~)
CVA - A~ient Vater Quality
Cr iter i a (AWt) (Sect ion 304)
CAA - NAAQS for Total Suspended
Pilrt irul rites (40 erR 50)
DEP - Air Quality <310 CMR 6-00)
Threshold limit Values (TlVs)
Appl icable
To be Con~idered
Appl icable
Relevant and
Appropriate
RrleVimt and
Appropriate
Appl irablr
Appl icable
These standards apply to alternatives involving
con~truction and operation of groundwater treatment
systems.
Prescribes proposed standards for VOC emissions from
unites such a~ air strippers.
These standards were issued as consensus standards for
controlling air quality in work place environments.
TlVs could be used for assessing site inhalation risks
for excavation activities.
Federal AWC are criteria for protection of human
health which have been developed for 95 Carcinogenic
and noncarcinogenic compounds.
This regulation specifies maximum primary and second-
ary 24-hr. concentrations for particulate matter.
fugitive dust emissions from site excavationJ
activities mu~t be maintained below 150 ug/m . 24-hour
arithmetic average for particles having a mean
diameter of 10 microns or less.
Regulations ~pecify maximum primary and secondary 24.
hour concentrations for particulate matter.
These standards were issued as consensus standards for
controlling air quality in work place environments.
TlVs could be used for assessing site inhalation risks
-------
1.
Chemical-Specific ARARs
Chemical-specific ARARs are identified in Table 11-1. In the following
discussion, these ARARs are described by affected media requiring
remediation and media that may receive discharges as a result of remedial
action (i.e., air). .
f,
Surface Water: Massachusetts has incorporated Federal Ambient Water
Quality Criteria (Clean Water Act - section 304) as state standards (314
CMR 4.00) for several of the contaminants of concern (see Table 11-1).
These state standards are applicable as chemical-specific requirements in
determining effluent discharge limits, although the discharge will be
occurring from an on-site treatment facility, most likely to an on-site
receiving water. The criteria will be met by setting effluent discharge
limits, designing and constructing a treatment plant to meet those levels,
and by monitoring the effluent and receiving waters to assure compliance
with the criteria.
Air: Federal Primary and Secondary National Ambient Air Quality Standards
(NAAQS) do not exist for volatile emissions of the compounds present at the
Nyanza site and downgradient area. Thus, there is no NAAQS applicable or
relevant and appropriate to volatile emissions. Such emissions could
potentially emanate from the treatment facility, especially if the air
stripping technology is selected following pilot studies. Federal Air
Quality Standards for particulate matter do exist and will be used in
assessing excavation and treatment emission controls. These standards are
relevant and appropriate, rather than applicable, since they were
originally developed to control stack and automobile emissfons. Threshold
Limit Values (TLVs) established by OSHA regulations provide an extensive
list of control levels which are applicable to on-site remediation
activities such as construction of the extraction wells and collection
network. Massachusetts Air Pollution Control Regulations (310 CMR Section
6.00-8.00) are applicable to the evaluation of air emissions associated
with remedial .actions at the Site (e.g., groundwater treatment systems).
Also, Massachusetts Guidance on Acceptable Ambient Air Levels (AALs) and
Threshold Effects Exposure Limits (TELs) will be considered rather than
being deemed relevant and appropriate since they are not promulgated
criteria.
Air related ARARs will be met through the use of engineering controls and
monitoring during design and construction of the remedy, and by the
possible utilization of emissions controls during operation of the
treatment facility.
2.
Location-Specific ARARs
Potential location-specific ARARs for the Nyanza Site and its environs are
identified in Table 11-2.
Wetlands/Floodplains: Several Federal and State Laws and Regulations
regulate activities in wetlands and floodpla.ins. Under Federal Law, the
Clean Water Act (Section 404) regulates activity in the vicinity of
wetlands. The CWA requires that the effects on wetlands be evaluated and
no activity that adversely affects a wetland be permitted if a particular
alternative having less effect is available. This requirement is.
applicable and will be met by avoidance of activities in the vicinity of
wetlands. EPA's regulations contained in 40 CFR Part 6, Appendix A
describes EPA's policy on implementing Executive Order 11990 (Wetlands
-------
Protection}. The procedures substantiatively require that EPA conduct its
activities to avoid to the extent possible, the long- and short-term
adverse impacts associated with the destruction of or modification of
wetlands. The procedures also require EPA to avoid direct or indirect
support of new construction in wetlands wherever there are practicable.
alternatives and to minimize potential harm to wetlands when there are no
practicable alternatives. The selected alternative is not likely to have
any significant impact on wetlands. Although there are wetlands located on
the Site, remedial activities will not be carried out in the wetlands. In
addition, the remedial activities in the selected remedy will not take
place in a floodplain, and thus the require~ents relating to floodplains
are not applicable.
The Massachusetts DEP Wetlands Protection Laws (310 CMR 10.00) are
applicable to all remedial alternatives involving work in or within 100
feet of a wetland. Specific requirements and restrictions of these ARARs
are presented in Table 11-2. It is not anticipated at this time that
activities within 100 feet of a wetland will be required. If during the
design phase it appears that the remedial alternative will affect wetlands,
the requirements described in Table 11-2 will be complied with.
"
n
3.
Action-Specific ARARs
Action specific ARARs for the selected remedy are presented in Table 11-3.
Major requirements that must be attained are discussed in the following
brief descriptions.
Water Requlations: Several regulations promulgated under the Clean Water
Act (CWA) are applicable to remedial activities that involve groundwater
treatment, and discharges to surface water. Although on-site CERCLA
actions do not require permits, the substantive NPDES permit requirements
for point-source discharges are applicable. These regulations include,
but are not limited to, requirements for compliance with water quality
standards, a discharge monitoring system, records maintenance, development
of and adherence to an NPDES Best Management Practice Program, and
construction and operation of a treatment system which meets the
technological requirements of the CWA. Toxic Pollutant Effluent Standards
(40 C.F.R. section 129), special requirements under NPDES for several
pollutants including benzidine, are relevant and appropriate because the
on-site discharge is subject only to the substantiative requirements of the
permitting program. Table 11-4 details the expected influent
concentrations and calculated discharge standards to meet the water quality
criteria in the Massachusetts Surface Water Quality Standards based on the
FS assumptions of the discharge location and dilution rates. Case-by case
technologically based discharge limitations will be established during
design based in part on Pre-Design studies of the treatment systems
described in section X.
Substantive requirements .of the Massachusetts Surface Water Discharge
Permit Program will be applicable to on-site surface discharges. Numerical
standards that Massachusetts has adopted (under 314 CMR 4.00) from the
Federal Aquatic Water Quality Criteria for several contaminants of concern
will be applicable in determining effluent discharge limits to the
receiving water.
Massachusetts also has a withdrawal Permit requirement for registration of
groundwater or surface water withdrawals greater than 100,000 gallons per
day (Massachusetts Water Resources Management Program). The current
-------
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-------
((,)
(5)
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st,'ndard<., allowing for thr 7010 (1.~ cfs) for the Sudhury Rivrr in thr vicinity of the propo<.rd effluent outfall for iiqUatic critrria a,wf th..
A"rrage IInnual flow (~8 cf~) for th.. huniln health. Instantan..ous and complete mi.ing of th.. riv..r and effluent was ass~d ilt th.. point of
dischargt'. 'he pxtraction flow was 50 gpm.
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component costing purposes, the CRDl was u<...d to calculatf' thf' ..ffluf'nt r..quire"",nts.
For treat"",nt
-------
estimated withdrawal of 70,000 gallons per day for the selected remedy will
not trigger the substantiative requirements of this program, but this
estimate is subject to change pending pre-design work. If the withdrawal
rate of the selected remedy exceeds 100,000 gallons per day, 310 CMR 36.00
may be applicable. A groundwater hydraulic analysis would be required
which includes the following components: the identification of all surface
water resources within a 1000 ft. radius: and a prediction of the drawdown
'impact of the extraction system on all identified users and resources. .
Clean Air Requlations: Relevant and appropriate requirements for
activities that involve excavation (including well installation, collection
system installation, and treatment plant construction) and air emissions
from operating treatment facilities include the National Air Quality
Standa~ds for Total Suspended Particulates under the Clean Air Act (CAA).
The specific standards are presented in Table 11-3. If a remedial
alternative involves air stripping or other air emission from a stationary
source, the Massachusetts Air Pollution Control regulations are also
applicable. The specific requirements are presented in Table 11-3.
Proposed Standards for Control of Emissions of Volatile Organics - 52 FR
3748 (February 5,1987) prescribes proposed standards for the emissions of
volatile organics from units such as air strippers. Since these standards
are proposed, this regulation is neither applicable nor relevant and
appropriate, but is to be considered if the air stripper eventually is
selected as the appropriate technology after pilot testing. Air emissions
from a potential air stripper are to be controlled in accordance with OSWER
directive 9355.0-28, June 15, 1989.' This directive calls for the addition
of controls should certain VOC emission rates be exceeded. Since VOC
emissions contribute to ozone production and the Site is located in an
ozone non-attainment area, the Region has determined it is necessary to
control VOC emissions from the air stripping unit (if implemented)
regardless of the VOC emission rate, in accordance with Regional policy.
Treatment of the air stream by carbon adsorption will prevent both exposure
through inhalation and will prevent the production of ozone resulting from
emissions of additional VOCs to the air.
Hazardous Waste Requlations: The Massachusetts Division of Water Pollution
Control containing supplemental requirements for Hazardous Waste Management
facilities are relevant and appropriate for the selected remedy, 314:CMR
8..00. The treatment facility planned is a "wastewater treatment unit" as
defined in 314 CMR 8.02. The facility shall comply with:
.
a) the management standards of 310 CMR 30.500, including: general
waste analysis: security: general inspection: personnel training:
contingency plan: emergency procedures, preparedness and'prevention:
recordkeeping and reporting: general requirements for ignitable,
reactive, or incompatible wastes: closure: and, where applicable,
post-closure.
b) the technical standards of 310 CMR 30.600, including general
requirements for all facilities.
The FS identified RCRA regulations set out in 40 CFR Part 264 as an ARAR
applicable to the selected remedial alternative. However, after further
consideration, EPA has determined that Part 264 is not an ARAR. This is
because 40 CFR Part 264.1(g) (6) provides that the requirements of Part 264
do not apply to the "Owner or operator of...a wastewater treatment unit as
-------
defined in Part 260.10..." The treatment facility planned for this
remedial action is a "wastewater treatment unit" as defined in Part 260.10.
Although RCRA subtitle C Land Disposal Restrictions (LDRs) were identified
in the FS as an ARAR applicable to the disposal of treatment residuals,
because there will be no disposal of RCRA waste occurring on-site, RCRA
disposal requirements are not an ARAR. ARARs address material that is left
on-site. Material that is shipped off-site is subject to RCRA disposal
requirements, but those requirements are not ARARs. If the residuals from
the treatment unit are determined to be a RCRA waste, off-site disposal of
the residual will be in compliance with LDR requirements.
9
Massachusetts has relevant and appropriate hazardous waste regulations at
314 CMR 30.00, providing a comprehensive program for the handling, storage,
generation, transportation, treatment, use, re-use, and recycling of
hazardous waste and record keeping requirements for the mentioned
acitivites.
other Action-Specific Requlations: occupational Safety and Health Act
(OSHA): Federal OSHA requirements that regulate worker safety and employee
records must be followed during all Site work. These regulations include
safety and health standards for Federal service contracts and record
keeping, reporting and related regulations. Since these regulations govern
general working conditions within industry and provide minimum protec~ion
standards for workers involved in remedial actions, these regulations are
applicable.
The FS identified Department of Transportation (DOT) rules for
Transportation of Hazardous Materials and Standards Applicable to the
Transporters of Hazardous Waste-RCRA section 3003, 40 CFR Sections 262 and
263, 40 CFR 170 and 179 as ARARs applicable to the transportation of
hazardous materials off-site. As explained above in connection with RCRA
LDR requirements, because these requirements do not address the handling of
hazardous waste on-site, they are not ARARs. Of course, these requirements
will be met when waste is transported off-site.
Massachusetts has Hazardous Substance "Right to Know" regulations
establishing requirements to protect health and safety of employees and
community residents through the communication of information regarding
toxic and hazardous substances. These regulations are applicable to on-
site workers involved in the remedial action.
C.
The Selected Remedial Action is Cost-Effective
In the Agency's judgment, the selected remedy is cost effective, i.e., the
remedy affords overall effectiveness proportional to its costs. In
selecting this remedy, once EPA identified alternatives that are protective
of human health and the environment and that attain, or, as appropriate,
waive such ARARs as are relevant to this interim action, EPA evaluated the
overall effectiveness of each alternative by assessing the relevant two
criteria-- reduction in toxicity, mobility, and volume through treatment;
and short term effectiveness, in combination. Long term effectiveness and
permanence is not relevant to this interim remedy and is therefore not
being considered. The relationship of the overall effectiveness of this
remedial alternative was determined to be proportional to its costs. The
costs of this remedial alternative are:
Estimated capital Cost:
$5,260,000;
-------
Estimated Operation and Maintenance Cost (5 years, present worth):
$2,180,000
Estimated Total. Cost (present worth):
$7,440,000
D.
The Selected Remedy utilizes Permanent Solutions and Alternative
.Treatment or Resource Recovery Technoloqies to the Kaximum Extent
Practicable
Once the Agency identified those alternatives that attain or, as
appropriate, waive ARARs and that are protective of human health and the
environment, EPA identified which alternative utilizes permanent solutions
and alternative treatment technologies or resource recovery technologies to
the maximum extent practicable. This determination was made by deciding
which one of the identified alternatives provides the best balance of
trade-offs among alternatives in terms of: 1) reduction of toxicity,
. mobility or volume through treatment: 2) short-term effectiveness: 3)
implementability: and 4) cost to the extent that these factors are relevant
to an interim remedy. Long-term effectiveness and permanence was not
considered due to the interim nature of the selected remedy. The balancing
test emphasized the reduction of toxicity, mobility and volume through
treatment and considered the preference for treatment as a principal
element, the bias against off-site land disposal of untreated waste, and
community and state acceptance.'
The selected remedy provides the best balance of trade-offs among the
alternatives given the limited scope of the interim action selected.
Consideration of long-term effectiveness does not apply due to the short-
term nature of the selected remedy. The selected remedy will achieve
reduction of toxicity, mobility, or volume through treatment of the most
highly contaminated groundwater in a treatment facility, thereby reducing
the migration of contaminants. The selected remedy is highly implementable
since it is to be constructed in a limited area that is primarily
industrial in nature and will therefore require a minimum amount of
coordination with other government agencies and landowners. Finally the
selected remedy will achieve the goals of the interim action, that is
reducing migration of contaminants and gathering of further data for use in
selecting the final remedy, while costing the least of the active options
considered as interim options.
The Selected Remedy satisfies the Preference for Treatment Which
Permanently and Siqnificantly reduces the toxicity, Kobility or
volume of the Hazardous Substances as a principal Element
The principal element of the selected remedy is the extraction and
treatment of groundwater at the northern boundary of the site and its
subsequent discharge to the Sudbury River. This element addresses the
primary exposure pathway at the Site for this Operable Unit: contamination
of groundwater in both the overburden and bedrock aquifers. The selected
remedy satisfies the statutory preference for reduction in the toxicity,
mobility or volume to the extent possible in light of its limited scope by
extracting and treating contaminated groundwater at a location where it is
most contaminated and preventing its further migration to downgradient
areas. This interim Record of Decision will be followed by a final ROD
which will determine. what further actions, if any, will be necessary to
meet the preference for treatment which will permanently and significantly
reduce toxicity, mobility, or volume of hazardous substances.
E.
-------
XII. DOCUMENTATION OF NO SIGNIFICANT CHANGES
EPA presented a proposed plan for remediation of the Site in June 1991.
The management of migration portion of the selected alternative included
extraction of contaminated groundwater, treatment of the collected
groundwater and discharge of the treated effluent to the Sudbury River.
There have been no significant changes made to the plan as stated in the
Proposed Plan of June 1991.
-------
XIII. STATE ROLE
The Massachusetts Department of Environmental Protection (DEP) has reviewed
the various alternatives and has indicated its support for the selected
remedy. The State has also reviewed the Remedial Investigation, Risk.
Assessment and Feasibility Study to determine if the selected remedy is in
compliance with applicable or relevant and appropriate State Environmental
laws and regulations. The Massachusetts DEP concurs with the selected
remedy for the Nyanza Chemical Waste Dump Site. A copy of the declaration
of concurrence is attached as Appendix II.
-------
APPENDIX I:
-------
Nyanza Chemical Waste Dump Responsiveness summary
Preface
Q
The United states Environmental Protection Agency held a 30 day public
comment period from June 27, 1991 until July 26, 1991 to provide an
opportunity for interested parties to comment on the Remedial Investigation
(RI) report, Feasibility study (FS) and the June 1991 Proposed Plan
prepared for the second Operable Unit addressing groundwater contamination
from the Nyanza Chemical Waste Dump site in Ashland Massachusetts. For
more information regarding the remedial alternatives evaluated in the
Feasibility study and Proposed Plan, please see copies of both documents,
which are included in the administrative record for this Operable Unit.
EPA signed the first Operable Unit ROD on September 4, 1985 addressing on-
site sludges. The third Operable unit, addressing contamination of the
Sudbury River and its tributaries by the Site, is currently still in the
RI/FS Phase.
The purpose of this Responsiveness Summary is to document EPA responses to
the comments and questions submitted to EPA during the public comment
period. EPA has considered all of the comments summarized in this document
before selecting a final remedial alternative to address the groundwater of
contamination at the site. For information regarding community concerns
and site history see sections II and III of the OU II Record of Decision.
This Responsiveness Summary is organized into the following sections:
I. Overview of Remedial Alternatives Considered in the Proposed
Plan - This section briefly outlines the remedial alternatives
evaluated in the Proposed Plan, including EPA's preliminary
recommendation of a preferred alternative.
II. site History and Backqround on Community Involvement and
Concerns - This section provides a brief site history, and a general
overview of community interests and concerns regarding the Site.
,
III. Summary of Comments Received Durinq the Public Comment Period
and EPA Responses to These Comments this section summarizes and
provides EPA responses to the comments received from residents and
other interested parties durinq the comment period. In addition,
comments received from the Potentially Responsible Parties (PRPs) are
also summarized and EPA's responses to these comments are provided.
IV. This section contains the transcript of the JulY 18. 1991
informal hearinq on the OD II proposed plan held in Ashland. .
Massachusetts.
v. This section contains the written comments received bY EPA durinq
the comment period.
-------
I.
overview of Remedial Alternatives considered in the Proposed Plan
EPA's selection of the preferred cleanup alternative for the Site as
described in the Proposed Plan was the result of a comprehensive evaluation
and screening process. The FS for the Site was conducted to identify. and
analyze the altern~tives considered for addressing contamination at the
site over the long term. The FS report for the Site describes the
alternatives considered, as well as the process and criteria EPA used to
identify the five potential remedial alternatives (designated Alternatives
RA-l through RA-5 in the FS report) to address groundwater contamination.
The cleanup plan EPA has selected in the accompanying ROD is essentially
the same as the preferrred alternative in the Proposed Plan, RA-2.
After analyzing the results of the FS, EPA proposed an interim remedy, not
a permanent remedy, as the preferred alternative. The main factors for
. this choice were the length of time projected in the FS that may be
necessary to attain the target levels set forth in the FS and the
uncertainty inherent in making such projections.. The main factors
contributing to the protracted cleanup times are: 1) the physical and.
chemical properties of some of the target contaminants; 2) the limited rate
at which groundwater can be extracted from the aquifer; and 3) the high
levels of groundwater contamination found throughout the study area. By
implementing the interim remedy, it will be possible to more accurately
predict how these factors will affect cleanup. In addition, the degree to
which contamination will continue to migrate from the Megunko Hill area
will not be known until the cap, which is scheduled for completion in late
1991, has been in operation for some time. Therefore, the interim approach
selected here will serve to collect data with which to refine the cleanup
time estimates for the final ROD.
EPA's preferred interim alternative (designated as RA-2 in the following
discussion) to remediate contaminated groundwater consisted of groundwater
extraction wells at the northern border of the Site; treatment of the
collected groundwater; and discharge of the treated effluent to the Sudbury
River. The alternative may also employ a collection trench at the northern
border of the cap now under construction on Megunko Hill, depending on
whether further study indicates that such a trench is feasible and
necessary. Figure 5-2 of the Feasibility Study shows the approximate
location of the proposed extraction wells and/or trenches for RA-2
(designated on Figure 5-2 as its companion, Extraction Component 2, or "EC-
2"). The preferred alternative will operate for a period of five years,
during which time environmental monitoring will be performed. After this
time period, EPA will evaluate the performance of the extraction and
treatment systems in a. final RI/FS and make a final remedy selection in a
subsequent final ROD for this Operable unit. The system will continue to
operate at least until the final ROD has been signed.
The preferred alternative will reduce contaminant migration in the
direction of groundwater flow (including into the Sudbury River) by
cleaning up the most highly contaminated area and sources of the
contamination. The FS estimated that attainment of groundwater cleanup
objectives using this alternative may take from several decades to
potentially several hundred .years in the groundwater extraction area
(Figure 5-2). This selected remedial alternative will not remediate
groundwater contamination in the eastern part of the plume in downtown
Ashland during the interim remedial period. By extracting groundwater near
the northern boundary of the Site, however, the preferred alternative will
prevent contaminant concentrations within the eastern portion of the plume
-------
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-------
from increasing, thereby preventing current potential risks from increasing
in this area.
The preferred alternative also included: 1) using institutional and access
controls to limit exposure to contaminants; 2) performing further testing
in the eastern portion of the plume to help determine the feasibility of
cleaning up groundwater in this area in the future; 3) installing
additional deep bedrock wells to more fully define the depths and locations
to which contaminants may have migrated; 4) performing continuous
monitoring of existing residential and monitoring wells to track any
further progress of the plume; 5) inspecting the Megunko Road waterline to
determine whether any deterioration has been caused by Site contamination;
and 6) performing pre-design studies to aid in the design of the selected
interim remedy. .
The construction of the groundwater treatment facility will require
approximately one acre of land, a system of collection wells and/or
trenches to collect the contaminated groundwater, and a piping network to
transport groundwater to the treatment facility. This alternative would
require less disruption to the nearby residential community than the other
alternatives considered since the collection system would be located mainly
on industrially zoned land. The system will be designed to be flexible in
order to accommodate potential changes in operation. For the purpose of
estimating the cost of the various remedial alternatives the FS analyzed,
as a representative technology, a groundwater treatment plant consisting of
precipitation, air stripping, and carbon adsorption treatment. EPA, in
consultation with the Commonwealth ot Massachusetts, will select the actual
technology to be used in the interim remedy from among the following
technologies: the air stripping technology outlined below, or ultraviolet-
oxidation or bi010qical treatment units in the place of the air-stripping
process as part of a comprehensive treatment system~ A predesign cost
effectiveness evaluation of the three technologies will be conducted in
order to select the two technologies for pilot testing. The final
selection of a groundwater treatment technology will be based on data
collected during the predesign .pilot studies~
Figure 10-2 of the Record of Decision illustrates how the air stripping
treatment process could remove contaminants from the aquifer and treat the
collected water to levels that are safe for discharge. Groundwater
extracted from the. aquifer would undergo precipitation, a chemical
treatment method that converts dissolved metals to an insoluble form and
allows suspended s01ids to accumulate and settle. After precipitation,
water would pass through a sand or cartridge filter to remove suspended
solids and would then enter an air stripper unit. Air strippinq is an.
aeration process that reduces concentrations of VOCs and some SVOCs by
changing contaminants in the groundwater into a gaseous form. A final
treatment process, carbon adsorption, would remove any remaining organics
in the water to levels acceptable by federal and state requirements for
discharge to the Sudbury River. Carbon adsorption removes organic
compounds by filtering and adsorbing dissolved and suspended contaminants
in the treated groundwater. Air emissions would also be controlled through
the use of carbon adsorption.
Estimated Time for Design and Construction: 3 years
Estimated Time of operation: 5 years
Estim~ted Capital Cost: $5,260,000
Estimated Operation and Maintenance Cost (5 years, present worth) :
$2/180,000
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-------
. Estimated Total Cost (present worth) :
$7,440,000
The Proposed Plan compared the preferred interim alternative to the other
alternatives that EPA retained for detailed analysis. The interim
alternatives discussed here are identical to the long-term alternatives
discussed in the FS, except that their comparison is based on a 5-year
operational period, rather than the 30-year time frame used for cost
purposes in the FS. Each of these alternatives is described briefly below,
along with a discussion of how each would function as an interim remedy.
Alternative RA-1: Minimal/No Action: The FS evaluated this alternative in
detail to serve as a baseline for comparison with other remedial
alternatives under consideration. Under this alternative, no treatment or
containment of groundwater contamination would occur. The objectives of
this alternative are to restrict public access and potential exposure to
Site contamination, prohibit use of contaminated groundwater, and evaluate
Site conditions and contaminant migration periodically over time. These
objectives would be accomplished using Site access control measures and
institutional controls to limit exposure to contaminants and installation
'of wells and long-term environmental monitoring. The FS estimates that a
period on the order of thousands of years could be required to meet the
groundwater cleanup objectives through natural flushing processes.
Consequently, the site control described here would be in effect for an
indefinite period of time. .
Estimated
Estimated
Estimated
Estimated
$721,000
Estimated
Time for Design and Construction: one year
Time of Operation, interim alternative: 5 years
Capital Cost: $320,000 .
Operation and Maintenance Costs (5 years, present worth) :
Total Cost (present worth): $1,041,000
Alternative
Boundary of
effluent to
alternative
RA-2: Management of Migration with extraction at the Northern
the Site: treatment of collected groundwater: discharge of
the Sudbury River: This alternative was the preferred
and is discussed above.
Alternative RA-3: Management of Migration with extraction to the north and
north-east of the Site as depicted in Figure 5-3 of the Feasibility ~tudy
(enclosed): treatment of collected groundwater: discharge of effluent to
the Sudbury River: This remedial alternative involves contaminated
groundwater extraction in the portion of the plume to the north and north-
east of the Site; treatment of the groundwater: and discharge of treated
groundwater into the Sudbury River. The treatment process is the same one
as was described under EPA's preferred alternative. This alternative also
includes the Site control features described for RA-l, which would be in
effect until cleanup objectives are met. The objective of this alternative
is to prevent the contaminants from expanding beyond current limits of the
plume and thereby prevent the discharge of contaminants to the Sudbury
River. The FS estimated that attainment of groundwater cleanup objectives
using this alternative may take from several decades to potentially several
hundred years. Although this clean-up time is essentially the same as the
estimate for RA-2 (the preferred alternative), this alternative would not
directly remediate the source area of the contaminated groundwater, thus
allowing potentially high levels of contamination to migrate by natural
processes to the extraction wells to the north and north-east of the Site
before being removed from the aquifer.
-------
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-------
As an interim remedy, this alternative would permit the collection of some
operational data, but it would also allow the continued migration of
groundwater contaminants from the Site.
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $3,870,000
Estimated Operation and Maintenance Costs (5 years, present worth):
$1,820,000
Estimated Total Cost (present worth): $5,690,000
Alternative RA-4: Management of Migration with extraction both at the
northern boundary of the Site and to the north-east of the Site; treatment
of the collected groundwater; discharge of effluent to the Sudbury River:
This alternative extracts highly contaminated source area groundwater by
combining the extraction components of the preferred Alternative RA-2 with
those of Alternative RA-3 as depicted in Figure 5-4 of the Feasibility
Study (enclosed). The collected groundwater would undergo treatment to
remove contaminants as described in the preferred Alternative RA-2.
Following treatment, the water would be discharged to the Sudbury River.
This alternative would include the Site control features described for
Alternative RA-1, which would be in effect until cleanup objectives are
met. The objective of this alternative is to prevent the contaminated
groundwater from expanding beyond its current boundaries and ultimately
into the Sudbury River. This alternative would also extract the most
highly contaminated groundwater to prevent increases in contamination to
the north and east of the Site. Based on estimates in the .FS, the time
required to achieve groundwater cleanup objectives may range -from several
decades to potentially several hundred years. This is essentially the same
as that for the preferred alternative, but would require much more
disruption to the community surrounding the Site, while capturing
contaminants over a larger area.
As an interim .remedy, this alternative would permit the collection of
operational data, while reducing the migration of contaminants throughout
the plume.
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $6,050,000
Estimated Operation and Maintenance Costs (5 years, present worth):
$3,140,000
Estimated Total Cost (present worth): $9,190,000
Alternative RA-5: Active Plume-Wide Extraction; treatment of the collected
groundwater; discharge of effluent to the Sudbury River: This alternative
is a comprehensive plume-wide alternative that differs from the others
because it involves extraction of contaminated water at many locations
throughout the plume as depicted in Figure 5-5 of the Feasibility Study
(enclosed). It also includes groundwater treatment as described for the
preferred Alternative RA-2, followed by discharge of the treated water into
the Sudbury River. Alternative RA-5 would also include the site control
features described for Alternative RA-l, which would be in effect until
cleanup objectives are met. The objective of this alternative is two-fold.
The first objective is to restore the aquifer by using numerous extraction
wells to minimize the transport of contamination through the aquifer and to
minimize the time frame required to complete treatment of the aquifer; the
second is to prevent migration and discharge of contaminated groundwater
-------
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-------
into the Sudbury River. Uniformly distributed extraction wells would
prevent highly contaminated groundwater from migrating to areas of lower
concentrations. The Feasibility Study estimates the time required to
achieve groundwater cleanup objectives by this alternative as ranging from
several decades to potentially more than two hundred years. .
As an interim remedy, this alternative would permit the collection of
operational data, while reducing the migration of contaminants throughout
the plume.
"
Estimated Time for Design and Construction: 3 years
Estimated Time of Operation, interim alternative: 5 years
Estimated Capital Cost: $6,650,000
Estimated Operation and Maintenance Costs (present worth, 5 years):
$3,430,000
Estimated Total Cost (present worth): $10,080,000
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II.
site History and Background on community Involvement and Concerns -
This section provides a brief site history, and a general overview of
community interests and concerns regarding the site.
1.
Backqround
The Nyanza Chemical Waste Dump Superfund Site - Groundwater study area is
located in the Town of Ashland, Middlesex County, Massachusetts (see Figure
1-1 of the ROD). Ashland is located in the Metrowest area of eastern
Massachusetts, bordered by Sherborn to the east, Southborough to the west
and northwest, Framingham to the north, and Hopkinton and Holliston to the
south. Ashland is 25 miles west-southwest of Boston, and 20 miles east-
southeast of Worcester.
The "Site", for purposes of describing the Operable Unit II - Groundwater
. Study, consists of all areas in and adjacent to the Nyanza property which
appear to be sources of groundwater contamination.2 The "Nyanza
property", which is a part of the Site, consists of approximately 35 acres
formerly owned by Nyanza, Inc. (Figure 1-2 of the ROD) and includes several
wetlands, the Megunko Hill area, and the lower industrial area along
Megunko Road. The Hill is located in the southern part of the property and
was formerly used as a landfill/disposal area. This area is currently the
focus of Operable Unit I remediation activities. The lower industrial area
was formerly the location of dye manufacturing facilities, the wastewater
treatment system and a series of settling. lagoons south of Megunko Road.
The areal extent of the Site is approximately bounded by an active Conrail
railroad line and Chemical Brook to the north, wetland areas and Cherry
Street to the east, and undeveloped mixed hardwood forest land to the
south, southeast, and west. The Sudbury River is approximately 700 feet
north of the Site.
The "study area" of the Operable Unit II - Groundwater Study is larger than
the Site. It consists of the Site plus the areal extent of well5
(approximately 395 acres) installed off the Nyanza property thus far.
2.
Land Use and Response Historv
From 1917 through 1978, the property was occupied by several companies
involved in manufacturing of several products. Textile dyes and dye
intermediates were produced on the site until 1978 when Nyanza, Inc. :
apparently ceased operations. Products manufactured on the property in
addition to those previously mentioned included inorganic colloidal solids
and acrylic polymers. starting in 1917, several types of chemical wastes
were disposed in various on-site locations with the majority of these
wastes deposited on Megunko Hill, which was used as an unsecured landfill.
Wastes included partially-treated process wastewater: chemical sludge from
the wastewater treatment process; solid process wastes (e.g., chemical'
precipitate and filter cakes) in drums; solvent recovery distillation
residue in drums; and off-specification products. Process chemicals that
2 For purposes of CERCLA ~ 121(e) (1) in so far as it
relates to permits, "on-site" shall be "the areal extent of
contamination and all suitable areas in very close proximity to
the contamination necessary for implementation of the response
actions". National oil and Hazardous Substances Pollution
contingency Plan (NCP), 40 CFR ~ 300.400(e).
-------
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-------
could not be ,recycled or reused (including phenol, nitrobenzene, and
mercuric sulfate) were also disposed of on-site.
Chemical wastes were also disposed of in the wetland areas. The eastern
wetland area received waste effluent discharge from various manufacturing
operations in the area. The northwest wetland area at the headwater of
Chemical Brook contained wastewater treatment sludge and possibly received
overflow from an underground concrete wastewater vault that discharged into
, Chemical Brook.
Nyanza, Inc., which apparently ceased operations in Ashland in
the most recent dye manufacturing company to occupy the Site.
plant grounds now are occupied by several industrial concerns,
of which is Nyacol Products, Inc. '
1978, was
The former
the largest
Nyanza, Inc. and its predecessors originally discharged the dye waste
stream to a concrete "vault" or settling basin adjacent to the main process
building. The vault was used as a central sump for the collection of
wastewater from the entire Nyanza, Inc. operation, as well as for other
generating tenants housed in the immediate vicinity. This vault was
approximately 40 x 80 feet and approximately 10 feet deep. The liquid
occasionally overflowed via a pipe into Chemical Brook which flowed into
Trolley Brook and through a culvert to the raceway that entered the
wetlands along the Sudbury River. The vault was taken out of service in
the 1960's or 1970's and was subsequently filled with sludge and covered
over with fill. As part of an ongoing effort to ease river pollution, the
Massachusetts Division of Water Pollution Control (DWPC) ordered Nyanza,
Inc. to install a pretreatment system for industrial process water and to
discharge the treated waste to the Metropolitan District Commission (MDC)
sewer collection system. Nyanza, Inc. connected to the MDC system in March
1970. '
The first type of contamination linked to the Site was mercury, discovered
in the Sudbury River in 1970, as part of an overall investigation of
mercury problems in Massachusetts for the DWPC. A follow up study in 1972
focusing on Nyanza, Inc. revealed mercury contamination in the Sudbury
River caused by uncontrolled sludge and wastewater disposal at the Site.
Since 1972, several investigations have been prompted by contamination
present at or originating from the Site. From 1972 through 1977, the
M~ssachusetts Department of Water Pollution Control (DWPC) and Department
of Public Health (DPH) cited Nyanza, Inc., for several contamination
problems associated with dumping activities. Following a 1973 DWPC order
to implement a plan to stop further groundwater pollution, Camp Dresser and
McKee, Inc. (CDM), working for Nyanza, Inc., performed a 1974 ,Site
investigation aimed at source identification and devised plans to control
groundwater contamination on the Nyanza property; however, the plans were
not implemented. In 1979, Edward J. Camille, a property owner, hired
Connorstone Engineering, Inc. to complete the CDM groundwater pollution
control program. However, the Massachusetts Department of Environmental
Quality Engineering (DEQE; now known as the Department of Environmental
Protection or DEP) halted these plans, pending further investigation. In
1980, DEQE released a Preliminary Site Assessment Report summarizing the
Site history and findings of previous investigations at the Site. MCL'
Development corporation acquired much of the property in 1981, and hired
Connors tone Engineering, Inc. and Carr Research Laboratory, Inc. to
characterize soil composition and locate sludge deposits.
-------
The Site was included on the original National Priority List (NPL) of
Superfund sites in 1982 and a preliminary Remedial Action Master Plan
(RAMP) was prepared. In 1984, the Environmental Protection Agency (EPA)
authorized NUS ,Corporation (NUS) to perform an Remedial
Investigation/Feasibility Study.
The September 4, 1985 Record of Decision (ROD) divided the Agency's
remedial response into Operable Units for the purpose of addressing
distinct problems. The September 1985 ROD was designated Operable Unit I.
The ROD selected soil and wetland excavation at nine localized areas of
contamination: solidification of water bearing excavated sludge, sediments,
and soil; and placement, capping and consolidation of those materials with
material left in place on the "Hill" area in the southern part of the Site.
A diversion trench has been constructed on the side of Megunko Hill above
and around the capped area to divert surface water flow and lower the
groundwater table beneath the cap as part of Operable unit I~ Construction
of the project began in early 1989 and will be complete in late 1991.
In 1985 the DEQE undertook an Interim Response Measure at the Site
consisting of the following activities: fencing the Trolley Brook Road
embankment; placing one foot of clean fill in one of the Site areas to
remove the threat of direct contact: and culverting Chemical Brook through
neighboring property.
In 1986, EPA authorized CDM to conduct additional field investigations to
define source locations and design the remedial action stipulated in the
ROD. The remedial design is complete and construction began in early 1989.
In January 1987, DEQE and the EPA Environmental Services Division (ESD)
initiated a sludge removal action of the contents within the vault (see
Figure 1-2 of the ROD). Prior studies by a DEQE contractor indicated that
the vault, and contaminated soil and groundwater in the vicinity of the
vault, were a significant source of organic contamination in the
groundwater downgradient of the area. contaminants present included, but
were not limited to, trichloroethene (TCE), chlorobenzene, and
nitrobenzene, all by-products of aniline dye production. Inorganic
contaminants found in the sludge included heavy metals such as antimony,
cadmium and chromium. Initially, the vault contamination investigation was
planned within the scope of Operable Unit II. DEQE and the EPA conducted a
subsurface investigation in the vault and surrounding area, culminating in
a decision to proceed immediately with remediation of the vault area. The
removal action was conducted by EPA's Emergency Response Team. From
October to December 1987, 665 tons of soil adjacent to the vault were
removed: 309 tons were incinerated, and 356 tons were shipped off-site to
an approved landfill. In March and June 1988, 2,512 tons of sludge from
the vault was solidified on-site' and disposed of at an off-site RCRA
landfill facility.
In June 1987, EPA authorized the REM III team to begin RI/FS activities for
Operable Unit II. Operable Unit II comprises groundwater contamination
related to the Site. A third set of RI/FS investigations, Operable Unit
III, is focused on contamination in the Sudbury River. Work on Operable
Unit III is being performed by NUS Corp. under an ARCS contract to EPA.
A more detailed description of the site history can be found in Section 1.4
of the Remedial Investigation Report.
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3.
Enforcement History
On April 4, 1982, EPA sent general notice letters to 18 entities it
believed were -responsible parties. On January 22, 1991, based on newly
acquired information, EPA notified approximately 21 parties who either
owned or operated the facility, generated wastes that were shipped to the
facility, arranged for the disposal of wastes at the facility, or
transported wastes to the facility of their potential liability with
respect to the Site. Some of the 21 parties named in the January, 1991
letters had been previously notified in the 1982 letters. An additional
owner/operator was notified on June 21, 1991 based on new information
supplied by existing PRPs. On July 22, 1991, eleven parties were removed
from the PRP list. EPA therefore considers twenty parties potentially
liable to perform or pay for the cleanup of the Site. EPA generally
condutts negotiations with potentially responsible parties (PRPs) as soon
as possible regarding the settlement of their liability at the Site. The
- PRPs have formed a steering committee and substantial discussions between
EPA and the steering committee have taken place.
The PRPs have been
Technical comments
summarized in this
comments have been
active in the remedy selection process for this Site.
presented by PRPs during the public comment period are
responsiveness summary, and the summary and written
included in the Administrative Record.
4.
Community Relations History
Throughout the Site's history, community concern and involvement has been
high. EPA has kept the community and other interested parties apprised of
the Site activities through informational meetings, fact sheets, press
releases and public meetings which have been held on an almost monthly
basis since 1986. These meetings served to update the public regarding the
progress of various aspects of the cleanup, including the groundwater
RI/FS.
During 1986, EPA released a community relations plan which outlined a
program to address community concerns and keep citizens informed about and
involved in activities during the planning and execution of remedial
activities.
Upon the start of construction of the cap and diversion trench on-site in
1989, EPA intensified its community relations efforts in response to public
concerns about safety issue related to the cleanup. For a several month
period, weekly meetings were held with representatives of the police and
fire departments, as well as with concern citizens and representatives of
organized labor unions. - -
On June 27, 1991 EPA made the Administrative
review at EPA's offices in Boston and at the
published a notice and brief analysis of the
News on June 21, 1991.
Record available for public
Ashland Public Library. EPA
Proposed Plan in the Middlesex
- On June 26, 1991, EPA held an informational meeting to discuss the results
of the Remedial Investigation and the cleanup alternatives presented in the
Feasibility Study and to present the Agency's Proposed Plan. Also during
this meeting, the Agency answered questions from the public. From June 27
to July 26, 1991 the Agency held a 30 day public comment period to accept
public comment on the alternatives presented in the Feasibility Study and
the Proposed Plan and on any other documents previously released to the
-------
public. On July 18, 1991, the Agency held a public meeting to discuss the
Proposed Plan and to accept any oral comments. A "transcript of this'
meeting, the pUblic's written comments and the Agency's response to both
written and oral comments are included in the following sections of this
Responsiveness Summary. .
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III. S~&rY of Comments Received During the Public Comment Period and
EPA Responses to These Comments
1.
Summary of, PotentiallY Responsible Party Comments and EPA Responses
Comment #1:
"
In general, all of the cited "options" for interim action are merely
different versions of the same plan (i.e., pump-and-treat), with varying
locations and numbers of extraction points. The National oil and Hazardous
Substances Pollution contingency Plan ("NCP"), at
40 C.F.R. ~ 300.430(e) (4), provides that with regard to ground water
response actions, the lead agency shall develop a limited number of
remedial alternatives that attain site-specific remediation levels within
different restoration time periods utilizing one or more different
technologies.
Response: The "options" or remedial alternatives referred to were selected
for final detailed analysis based on the screening process spelled out in
the Feasibility Study. Since the "pump and treat" technology was the only
one to survive that screening process, it was logical to compare collection
networks of varying sizes in the detailed analysis. The remedial'
alternatives that were developed do, therefore" . . . attain site-specific
remediation levels within different restoration time-periods utilizing one
or more different technologies" as required.
Comment #2
since pump-and-treat technology has yet to succeed in "cleaning up" any
Superfund site ground water down to federal drinking water standards such a
cleanup cannot be regarded as achievable using this 'technology. The sole
objective should therefore be the prevention of the spread of the
contamination plume (i.e., control versus remediation) and a general
overall reduction in the level of toxics in the plume.
Response: EPA disagrees with this comment. CERCLA Section 121(b) and the
National Contingency Plan state a preference for remedial actions that
utilize treatment which permanently and significantly reduces the volume,
toxicity, or mobility of the hazardous substances over remedial actions not
involving such treatment. The National Contingency Plan, ,
40 C.F.R. ~ 430 (a) (iii) (F) states that:
"EPA expects to return usable groundwaters to their beneficial uses,
within a time frame that is reasonable given the particular
circumstances of the site. When restoration of groundwater to
beneficial uses is not practicable, EPA expects to prevent further
migration of the plume, prevent exposure to the contaminated
groundwater, and evaluate further risk reduction."
The selected remedy comports with the preference for treatment set out in
CERCLA and the NCP. The remedy prescribes treatment for groundwater
contaminated with high concentrations of highly mobile toxics which were
released at the Site.
Further, since pump-and-treat cleanups are by their very nature long-term,
the fact that no Sites have reached MCL levels may be irrelevant to the
remedial decision at Nyanza. It can not be said that pump-and-treat will
not achieve groundwater cleanup goals.
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"Pump and treat" technologies have been used at numerous Superfund and
other Site where groundwater has become contaminated over the past decade.
Specifically, a study of 19 case studies around the United States (OSWER
Directive 9355.4-03) performed by EPA indicated that: .
"the extraction systems are gerierally effective in containing
contaminant plumes, thus preventing further migration of the
contaminants;
Significant mass removal of contaminants (up to 130,000 pounds
over three years) is being achieved;
Concentrations of contaminants have generally decreased
significantly after initiation of extraction but have tended to
level off after a period of time;
Data collection was usually not sufficient to fully assess
contaminant movement and system response to extraction."
Further, the Directive continued to make the following recommendations:
"initiate response action early;
Provide Flexibility in the Selected Remedy to modify the system
based on information gained during its operation:
Collect data to better assess contaminant movement and likely
response of groundwater to extraction."
The selected alternative recognizes all of the findings and recommendations
in the Directive and reconciles them to the situation in groundwater in the
Nyanza study area. The selection of RA-2 will limit the disruption of the
community and access related problems in an attempt to initiate response
actions early. The interim remedy, calling for the treatment of the plume,
recognizes the technology's ability to remove a large quantity of pollutant
mass in the relatively highly contaminated aquifer at the northern boundary
of the Site and follows the recommendation of the directive to provide for
longer term-flexibility. The interim remedy, of course, also provides a
forum within which data can be collected to support the third
recommendation of the directive.
Comment #3
The regulations require'the lead agency, in regard to source control
actions, to develop where appropriate alternatives that involve little or
no treatment, but provide protection of human health and the environment by
preventing or controlling exposure to hazardous substances through
engineering controls such as containment. 40 C.F.R. ~ 300.430(e) (3) (ii).
This requirement deserves further consideration and review.
Response: The Agency has in fact considered an alternative which satisfies
40 C.F.R. 9 300.430 (e) (3) (ii). RA-1 involves no treatment but attempts to
provide protection of human health and the environment by preventing or
controlling exposure to hazardous substances through institutional
controls.
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The rejection of RA-l as an interim remedy comports with the preference for
remedial action that utilize treatment which permanently and significantly
reduces the volume, toxicity, or mobility of the hazardous substances over
remedial actions not involving such treatment, as set out in CERCLA Section
121(b) and the'NCP. See response to Comment ~2.
Comment ~4
Q
If there is no proven applicable technology which is more effective than
pump-and-treat in five years (and there currently is no strong indication
that there will be), it is highly unrealistic to expect that a "final
decision" regarding remediation to MCL levels could be reached at that
time.
Response: It is anticipated that within 5 years, operational history of
the treatment plant and collection system will be obtained arid a much more
refined estimate of cleanup times developed. Based on the information
developed, EPA will make a final remedial decision. That decision may be
to set cleanup goals at MCL levels, to change cleanup objectives (for
instance to contain the plume, rather than to meet ARARs) and to develop
alternative concentration limits, or to waive certain ARARs if cleanup to
levels set by such ARARs is in fact found to be unattainable. EPA
disagrees that it is unrealistic to expect that a final decision will be
reached. '
Comment #5
Pump-and-treat systems may result in an initial reduction in contamination,
followed by a plateau. A return of contamination to initial or even higher
levels has been known to occur when the system ceases operation. This
possibility does not appear to have been adequately considered in the
Feasibility Study. Based on the contaminants identified, many of which are
nearly insoluble nonaqueous-phase li~ids (NAPLs), and the fact that the
overall quantity of these NAPLs released is not clearly known, such a
situation is a distinct possibility for the site. Perhaps the "decades to
centuries" cleanup estimate alludes to this factor. If so, this should be
a predominant factor in the system design and more reason to have plume
containment rather than aquifer restoration as the primary objective.
Response: Whether or not NAPLs are in fact present, the selected remedy
including the pump and treat system is the only one known to have any
chance of even containing highly concentrated organics. An important
component in the selected remedy is further pre-design studies which will
include further work to refine the locations of and the depths to which
NAPLs (assuming such deposits exist) may have migrated. If such locations
can be isolated and extraction systems placed in these strata, very large
mass removals will become evident.
If the scenario spelled out by the commenter in fact is evident at the
conclusion of the 5 year interim period, it is possible that the Agency
will decide to change the objective of the long-term cleanup. '
Comment #6
There does not seem to be ample justification for an interim 5 year
pump-and- treat program versus, for example, a 2-3 year program.
Specifically, it is not apparent that 5 years of operation will have
permanent effect than 2-3 years. The information does not show that
a more
the
-------
goal of "control and containment" nacessitates 5 years, nor does it
indicate that the agency has truly considered whether this is a more
realistic approach.
Response: Based on the clean-up time estimate in the proposed plan and
Feasibility study, it is apparent that the selected alternative will not
reach ARARs for groundwater within the 5 year time frame.
The extraction is presently estimated to take place at the relatively low
rate of 50 gallons per minute. This makes it likely that a significant
number of years will be necessary to judge the removal rates the system is
accomplishing. In addition, fluctuating hydrologic conditions which depend
on seasonal weather patterns make 5 years of data a valuable asset in
making a final decision. For instance two or three consecutive drought or
very rainy years could lower or raise the amount of recharge available to
. the aquifer and skew the data reflecting aquifer response to the remedy.
Hydrologic considerations over an extended perioq of time can be especially
important in considering the need for the optional downgradient groundwater
collection trench at the toe of the soon to be. completed Operable unit 1
Megunko Hill cap and upgradient diversion trench.
The five year time frame coincides with the Agency's mandate under 40
C.F.R. 9 section 430(f) (4) (ii) .to review actions at sites every five years
where remedial actions are selected that result in hazardous substances
remaining at the site at or above levels .that allow for unlimited use and
unrestricted exposure. Thus the five year period should require the least
overlap in the required review cycle. .
Comment #7
,
Finally, section 300.430(e) (5) of the NCP provides that one or more
innovative treatment technologies should be considered if those
technologies offer "the potential for comparable or superior performance o~
implement ability: fewer or lesser adverse impacts than other available
approaches; or lower costs for similar levels of performance than
demonstrated treatment technologies. "In light of the ineffectiveness of
the pump-and-treat technology for the remediation of ground water, the
information reviewed for the Proposed Plan does not mention whether other
so-called innovative technology (e.g" bioremediation) might be used
independently or in conjunction with pump-and-treat.
Response: A full range of innovative technologies was considered in the
Feasibility Study. The Feasibility. Study describes the reasons that each
of the innovative technologies were eliminated from consideration. In-situ
biological treatment in particular was screened out due to its inability to
operate in environments containing high levels of toxics, including metals:
and the extremely slow rate at which such treatment (even if uninhibited by
toxics) would presumably take place.
Comment #8
. It is not clear why the ground water cleanup standards are set at federal
drinking water levels when the water is not used for drinking or even for
recreational purposes. Section 300.430(e) (2) (i) (B) states the following:
"Maximum contaminant level goals (MCLGs), established under the Safe
Drinking Water Act, that are set at levels above zero, shall be attained by
remedial actions for ground or surface waters that are current or potential
sources of drinking water, where the MCLGs are relevant and appropriate
-------
under the circumstances of the release... " Section 300.430(e) (2) (i) (C)
states: "Where the MCLGfor a contaminant has been. set at a level of zero,
the MCL promulgated for that contaminant under the Safe Drinking Water Act
shall be attained by remedial actions for ground or surface waters that are
current or potential sources of drinking water, where the MCL is relevant
and appropriate under the circumstances of the release... " Since the
ground water at the site is not currently used and has little to no
potential to be used in the future for drinking water (particularly
considering the other industrial operations in the area), the. federal
drinking water standards should not be applied to the remediation goals.
Response: The Proposed Plan and the Record of Decision proposed and
selected an interim remedy which does not set groundwater cleanup levels.
Thus, the comment is not relevant to the interim remedy.
The Feasibility Study's cleanup time estimates for final remedies were
based in part on reaching federal drinking water standards. The lengthy
time estimates to attain such standards were a factor in choosing to select
an interim, rather than a final remedy.
The Federal Drinking Water standards were appropriate for use in the
Feasibility Study to evaluate final remedial alternatives. The aquifer is
classified as a Class I aquifer under the terms of 314 C.M.R. Section 6.00,
the Massachusetts Groundwater Classification standards. Thus, it is
appropriate to consider the aquifer a potential source of drinking water in
identifying cleanup levels in the FS for final remedies.
Comment #9
Since even the Feasibility Study accepts that "it may take many decades to
centuries of treatment" to achieve these federal drinking water levels,
this statement implies that such levels are, for all practical purposes,
unachievable using current technology. Thus, the distil'ction between
"centuries" of .treatment (at great cost) and thousands of years" of
non-treatment/natural flushing is academic at best, if not highly
speculative.
Response: As noted above, estimated times to reach target levels in the FS
are not relevant to the interim remedy selected in this Record. of De~ision.
It should be noted that the most lengthy of the clean-up time estimates for
any of the principal contaminants found in the plume are those .for 1,4
dichlorobenzene, a relatively immobile, highly adsorptive, insoluble
compound. These properties all add to the rather lengthy time estimate for
cleanup cited in the proposed plan and feasibility study. Other compounds,
which are more mobile, soluble, and less sorptive to soils such as
trichloro1oethene are expected to be cleaned up within a several decade
time frame. Removing these compounds from the aquifer, while not reaching
ARARs for the compounds less amenable to removal, will significantly lower
the potential risks from consuming contaminated groundwater.
The final cleanup decision will be based, no doubt, on a greatly expanded
data base and thus will be far less speculative than the current selected
alternative. Even based on the comparatively small number of samples now
available, an order of magnitude difference in restoration times is still
significant.
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Comment #10
The NCP provides generally that" [r]emediation goals shall establish
acceptable exposure levels that are protective of human healt~ and the
environment... " 40 C.F.R. ~ Section 300.430(e) (2) (i). Again, since there
are no private or public drinking water supply wells in the vicinity, the
current risk to human health from contaminated ground water is minimal.
Therefore, it does not make sense that the proposed cleanup objectives
include reduction in "risks to human health associated with potential
future consumption and direct contact with ground water" when there is no
reason to expect any requirement for such future consumption. Human
exposure can be further controlled by deed restrictions and water use
controls.
Response: Cleanup levels are not being set in the interim remedy selected
and thus the comment is not relevant to the selected remedy. Human
exposure is in fact being controlled by institutional controls including
deed restrictions and water-use controls as a component of the selected
remedy. EPA's response to the question regarding potential uses of the
aquifer in the future are contained in the response to Comment #8.
Comment #11
The Risk Analysis determined that health risks from ground water seepage
into basements was minimal, and implied that other health risks only arose
if the water became a source of household supply (which is not .
anticipated). Moreover, it is highly speculative to determine what exactly
are the true "risks from present and future inhalation of evaporated ground
water contaminants" and the probability of such exposure ever occurring
especially since exposure would be in open areas. The risks appear to be
minuscule at best, if not imaginary.
Response: The inhalation risks which were considered in the EPA Risk
Assessment concerned the possibility of such exposures to the residents
whose basements overlie the contaminated plume and the possibility of
exposures while showering in water collected from a private well. The Risk
Assessment did conclude that such risks are minimal for the basement
exposure scenario, however, the private well scenario (of which the
showering exposure was a component) risk estimate was is in excess of EPA's
target risk range by a considerable margin.
Comment #12
In general, the information reviewed in the Risk Analysis does not support
the preferred option nor any of the other options. .EPA appears to have
conducted a rather flawed evaluation process with their analysis
conflicting with their recommended actions. Perhaps the agency was
motivated by its perceived need to have to "do something", and by local
pressures.
Response: The Risk Assessment indicated that the risks due to exposure to
private well supplies within the plume area are above the target risk range
cited in the NCP of 10.' to 10-6. The need to reduce those risks supports
the recommended action, which is the selected alternative in this ROD.
Comment ~13
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using the information reviewed, the proposed costs for installation and
operation of the pump-and-treat system appear to be high. Moreover, the
time to design and install the system also appears lengthy. ' section
300.430(e) (7) '(iii) provides that cost shall be a factor in considering
the remedial alternatives. "Costs that are grossly excessive compared to
the overall effectiveness of alternatives may be considered as one of
several factors used to eliminate alternatives." In light of the highly
,questionable long-term effectiveness of pump-and-treat technology for this
site, the costs for installing and operating this system for an excessive
period of time raise additional questions about the selection of the
preferred alternative.
Response: The cost estimates were developed in the Proposed Plan as 5 year
alternatives. The selected alternative was not the least or most costly
developed. Cost was considered in selecting the interim remedy as required
by the NCP. Further, the question of long-term cost and effectiveness will
be dealt with in the context of a final Record of Decision based on pre-
design studies and the operational history of the remedy. ,The commenter's
statement regarding long-term cost effectiveness is not relevant to the
five year interim remedy.
Comment # 14
Several commenters questioned whether EPA intended to add to the PRP list
for the site landowners who own property within the "Nyanza Contaminant
Groundwater Plume" as shown on Figure 3 of the EPA's June 1991 Proposed
Cleanup Plans for operable unit 2?
Response: This comment relates to enforcement matters and is not a comment
relevant to remedy selection. It would be inappropriate for EPA to comment
on enforcement matters at this time.
Comment # 15
A certain individual was a one time the plant manager for the Nyanza
Chemical Company at the same time that he was the Chairman of the Ashland
Board of Selectmen and the Ashland Board of Health. The Town of Ashland
should therefore be named as a potentially Responsible Party since this
individual had a conflict of interest in not responding to complaints about
d~sposal practices at the plant.
Response: This comment relates to enforcement matters and is not a comment
relevant to the selection of the remedy. It would be inappropriate for EPA
to comment on enforcem~nt matters at this time.
Comment # 16
It is apparent that the groundwater contamination has migrated beyond the
Nyanza property boundary into what is called the Nyanza site study area.
The possibility that bedrock and surficial geological compartments may act
as sources of contaminants following remediation of site-specific sources
(e.g. Megunko Hill, vault area) is noted. This finding may have
significant implications on the costs and timetables for potential
remediation strategies. We would like to review any additional future
assessments of the effects of Nyanza I remediation actions on the Nyanza II
RI/FS process. We would like an opportunity to review the companion
reports on risk assessment and the feasibility study. In particular, we
would like to review cost/benefit analyses of various alternatives in
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relation to human health risk assessments. It is apparent that the Nyanza
I, II, and. III will be a very costly and long remediation program.
Consequently we are concerned with the optimization of the cost/benefit
relationship in future remediation actions.
Response: It is inferred that the comment regarding geologic compartments
acting as "sources" of contaminants refers to the possible presence of
NAPLs. See Response to Comment #6.
~
The effects .of the Nyanza I remediation effort will be looked at during the
implementation .of RA-2 as part of the effort to ascertain whether a
downgradient groundwater collection system near the Operable unit 1 cap,
now nearing construction, will be necessary.
The Feasibility Study and Risk Assessment, as well as all other supporting
documents for this Operable unit have been available since June 27, 1991 at
the information repositories located at the Ashland Public Library and the
EPA Records Center, 90 Canal Street, Boston, 1st Floor. A companion
Ad~inistrative Record for the Operable unit 1 Record of Decision is also
located at the same repositories. .
The consideration of costs in the remedy selection process are outlined in
the Feasibility Study, Proposed Plan and in the attached Record of
Decision.
EPA will make its final decision with regard to this Operable Unit based on
information which will be made available to the public in an administrative
record.
2.
Summary of Resident and Town Official Comments
Comment # 17
Although supportive of the proposed plan's cleanup objectives and interim
pump-and-treat approach, one commenter stated that the selected alternative
would not meet the stated objectives as well as or as completely as
remedial alternative 4 (RA-4) or an expanded version of the selected
alternative in the area outside of the zone of influence of the proposed
extraction alternative (RA-2). The commenter suggested that further
consideration be given to an expansion of EPA's preferred alternative to
effect groundwater cleanup over the entire area of contamination in an
attempt to more fully achieve its goals. The additional wells in the
Forest Avenue or Tilton Avenue a~ea would more fully effect the cleanup, be
less disruptive (than alternative RA-S), add a minimum of cost and more
fully realize each of the cleanup goals. .
Response: The migration of contaminants into the area unaffected by the
extraction scheme in RA-2 will be reduced due to the removal of contaminant
mass at locations feeding the plume in the vicinity of the Site. Reduction
of risk to human health associated with potential future consumption and
direct contact with groundwater and from risk due to present and future
inhalation of evaporated groundwater contaminants will be achieved using
institutional controls both within and outside the zone of influence of the
Alternative RA-2 extraction scheme. In EPA's judgement, placing additional
wells outside the immediate Site area at this time would cause disruption
to residential areas and the selected remedy as an interim remedy is
protective. As stated in the section of the June, 1991 Proposed Plan
entitled "Proposed Cleanup Objectives and Levels", RA-2 is proposed as an
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interim step towards meeting a final Record of Decision to address the
entire contaminated plume area. Thus, work will include performing further
testing in the eastern portion of the plume to help determine the
feasibility of. cleaning up groundwater in this area in the future, and
performing monitoring of existing monitoring wells to track any further
progress of the plume. Until this work is complete and the effectiveness
of the alternative RA-2 is monitored over the 5 year interim period, it is
premature to decide upon the necessity of the construction of an enlarged
collection network or to enumerate the exact numbers of extraction wells to
be built.
Comment #18
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One commenter suggested that Alternative RA-S should be implemented for the
following reasons:
"Although your report states that RA-2, RA-4 and RA-S when viewed as
interim remedies, would provide similar information leading tho the
choice of a final remedy, it also states that "over a five year
period, alternative RA-5 would provide the most effective removal of
contaminants because wells would be placed at many locations
throughout the study area.
If alternatives RA-2 through RA-5 all reduce toxicity, mobility, and
volume of organic contaminants; and alternative RA-2 reduces the
mobility, toxicity, and volume of organic compounds less than
alternatives RA-3, RA-4, and RA-S, because it treats a smaller portion
of the entire plume; and if RA-2 is superior to RA-3 since it attempts
to capture contaminants closer to their source; then RA-S must be
superior to RA-2 because it treats the entire plume.
"The Proposed Plan also states that "RA-2 with its focus primarily in
an industrial area would cause the least ...disruption because of its
many locations". The residential area concerns presented in the
short-term effectiveness and implementability criteria would be
mitigated by using other available industrial and/or residential B
land, located on the plume. Gordon-Mindick Properties could make
available land/or buildings that would allow for the effective removal
of contaminants from the entire plume in an area that would cause the
least amount of disruption to a residential area~"
Response: The Comparative Analysis in the proposed plan indicated that
RA-2 would be superior to the other active alternatives (RA-3 through RA-S)
since it would allow for the collect'ionof data to be used in the final
selection process, while addressing the area of highe~t contamination, at
the least cost, and with the least disruption to the community outside the
Site area. All of these factors were balanced towards selecting the RA-2.
EPA understands that Gordon-Mindick Properties is at this time willing to
make land available for the installation of facilities in the eastern area
of the plume. Such land may be considered during the final decision making
process, following implementation of the interim remedy. This offer does
'not however change EPA's judgement that RA-2 is superior as an interim
remedy because it will allow the collection of the information necessary to
make a final decision. while causing less disruption to the surrounding
community.
Comment #19
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The Ashland Board of Health endorses EPA's proposed remedial action plan,
RA-~ because the more expansive extraction altern~tives present the
possibility that "..a release of contaminants, either in the liquid or
gaseous state, ~rom the wells or the pipelines into the residential area"
could occur.
Response:EPA acknowledges the support of the Ashland Board of Health.
Although the possibility of such a release could probably be made very
remote through conservative construction practices, it is nonetheless true
that the risk is greater for alternatives using more wells and larger
collection schemes.
,
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Nyanza Chemical Waste Dump site Responsiveness Summary:
section IV: Transcript of Comments Received During July 18, 1991
Public Hearing
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COMMONWEALTH OF MASSACHUSETTS
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
PUBLIC HEARING before the Environmental Protection
Agency, held at the AShland High School, Ashland,
Massachusetts, on Thursday, July 18,
1991,
commencing at 7~10 p.m., concerning:
E.P.A. PROPOSED CLEANUP PLAN FOR THE
NYANZA CHEMICAL WASTE DUMP SITE
BEFORE:
Pamela Shields, Biologist, as Hearing Officer
David Lederer, Remedial Project Manager
Jay Naparstek, Senior Project Manager
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MARIANNE KUSA-RYLL
REGISTERED PROFESSIONAL REPORTER
P.O. BOX 610, 252 JUSTICE HILL ROAD
STERLING, MASSACHUSETTS 01564-0610
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1 I N D E X
SPEAKERS:
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3 David Lederer
4 Joel Silverstein
5 Henry Fassler
6 Barry Bresnick
7 John Ellsworth
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PRO C E E DIN G S
HEARING OFFICER SHIELDS:
Okay.
I
guess we should get started.
Good evening.
My
name is Pam Shields.
I am a biologist at the U.S.
Environmental Protection Agency, and I am going to
be the Hearing Officer for tonight's hearing on
the proposed cleanup for the groundwater
contamination at Nyanza.
First, I would like to introduce the
other members of the panel up here for those of
you who don't know them.
At the far right is
Jay Naparstek, who is with the Massachusetts
Department of Environmental Protection; and
closest to me is David Lederer, who is the Project
Manager for E.P.A.
For those of you who are unfamiliar
with the Nyanza site, E.P.A. has divided the site
into three phases or operable units.
The first
phase deals with soils and sediment on site, and
these are currently being excavated, stabilized,
and consolidated with the rest of the waste that
is on the hill of the site and will then be capped
after the consolidation.
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4.
under way and is under the management of the
u.s. Army Corps of Engineers, and is nearing
completion.
The cap should be completed this
year.
The second phase of the project
addresses contaminated groundwater and is the
subject of tonight's hearing.
The third phase of the project
addresses contamination in the Sudbury River, as
well as the wetland area immediately adj~cent to
the site.
The third phase is currently undergoing
a remedial investigation to determine the nature
and extent of the contamination and to evaluate
the risk to human health and the environment based
on contamination in the river.
Back on June 26, the E.P.A. held a
public hearing here to present the results of a
~easibility study, which examined the various
alternatives to clean up the contaminated
groundwater and then presented the E.P.A.'s
preferred approach to the cleanup.
This was
followed by a question and answer period.
After I finish my introductory remarks
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recap the proposed plan,
and then we will begin
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the actual hearing.
'"
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The purpose of the hearing tonight is
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to allow the public comment on the
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E.P.A.'s proposed cleanup strategy for the
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groundwater.
We will be transcribing the meeting
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and will later produce a printed transcript, which
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will become part of the administrative record
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which is used by the E.P.A. to make the final
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remedy decision.
If you want to buy your own copy
of the transcript, you should make arrangements
directly with the transcription service.
In order to ensure accuracy of the
record, I ask that anyone who wishes to make a
statement fill out an index card, which were
provided outside, with their name, address and
affiliation,
if any.
I will then call on people
in the order that they have signed up, and they
can make their statement.
I have to reserve the
right to limit time available for individual
statements to ten minutes so that everyone who
wants to make a statement will get a chance to.
I want to make it clear that tonight's
hearing is not for questions and answers.
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will not be responding to questions; however, you
may ask questions, and they will become part of
the record, and the E.P.A. will respond to them in
our Responsiveness Summary, which will be part of
our final decision document, which will be coming
out later this fall.
In addition to statements of tonight's
hearing,
you can also submit written comments for
E.P.A.'s consideration.
These comments should be
directed to David Lederer, and the address is
given in the proposed plan.
The written comments
must be postmarked no later than July 26, 1991.
Finally, I want to remind you that
copies of the Administrative Record are located at
the Ashland Public Library and at E.P.A.'s offices
in Boston and that you can review these materials
at your convenience during normal business hours.
Before I turn it over to Dave, are
there any questions regarding the hearing format
or public participation in the process?
Dave.
MR. LEDERER:
Hello, everyone.
Glad
to see we have so many people turn out tonight on
such a hot night.
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recap what is in the proposed plan so that we can
get on with what the real business of tonight is,
which is hearing from the people.
We are here to talk about the
groundwater remedy, an intro groundwater remedy,
for the Nyanza site.
As you mayor may not know,
the original Record of Decision was signed in 1985
for the site, which involved a decision to build
the cap project, which is now nearing completion.
since 1988, E.P.A. has been conducting studies of
the groundwater contamination problem, which
emanates from the site and has moved to areas
which" are north and east of the site.
Over the course of the investigation,
E.P.A. drilled two sets of wells in 1988 and
in 1990, and we discovered that groundwater
contamination consisting of organic contaminants
and inorganic contaminants had moved north and
east of the site and are presumably intercepted by
the sudbury River.
For those of you who have the
proposed plan, the approximate extent of the
ground~ater plume is shown in figure three.
The preferred alternative, the
one we
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tonight, we should say,
is an interim remedy.
An
interim remedy is designed to take action to
protect human health and the environment in the
short term, while a final remedial action is being
developed.
The interim remedy, which we are
talking about tonight, will operate for a minimum
of five years.
A final Record of Decision, or
R.O.D. as you will hear us call it, for
groundwater will be based on the data collected
during the design, operation and monitoring of the
remedial remedy.
Some of the things that the remedy
includes
are:
Extracting contaminated groundwater
for that five~year period from the northern
portion of the site near the railroad tracks and"
the industrial park along Megunko Road and
optionally at the southern boundary of the .cap now
being constructed on Megunko Hill; treating that
groundwater with a combination of processes;
discharging the treated water into the Sudbury
River after treatment; using institutional and
access controls to limit exposure to the
underground contaminants; performing testing of
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portion of the plume to help determine the
feasibility of cleaning up groundwater in that
area; installing additional deep bedrock wells to
more fully define the depths and locations to
which contaminants may have migrated; performing
continuous monitoring of existing residential and
monitoring wells to track any further progress of
the plume; inspecting the Megunko Road water line
as a precautionary measure to make sure there
isn't any possibility that wastes have caused the
line to deteriorate; performing predesig'n -studies
to aid in the design of the selected remedy.
That pretty much summarizes what the
proposed plan says.
If people have questions
about it, as Pam said,
the format of the hearing'
is that statements are made by the people in
attendance.
We are not responding to the
questions during the. meeting.
If people want to
approach me after the meeting is over, that is
fine.
With that, I will turn it back to
Pam.
HEARING OFFICER SHIELDS:
Thanks,
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Okay.
We will now begin the hearing,
and the first person who is signed up to speak
tonight is Joel Silverstein.
JOEL SILVERSTEIN:
.Thank you.
My name is Joel Silverstein.
I am
representing Morton Mindy Properties at 1050 Main
Street here in Ashland.
What we would like to --
HEARING OFFICER SHIELDS:
Could I ask
that you speak up a little.
We are having trouble
hearing.
JOEL SILVERSTEIN:
So.rry.
My name is
Joel Silverstein, and I represent Morton Mindy
Properties at 1050 Main Street here in Ashland,
and we would like to go on public record asking
that the entire plume be treated, and that the
alternative RA-5 be implemented.
To that end, we
can or could provide industrial land, residential
B land and/or industrial buildings to meet those
ends.
In addition, I would like to submit
this stat~ment, for the record.
In the spirit of
being brief, I just assume submit it rather than
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Thank you.
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HEARING OFFICER SHIELDS: Okay.
The
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next speaker is Doctor Henry Fassler.
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HENRY FASSLER:
For the record,
I am
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Doctor Henry Fassler,
Chairman of the Ashland
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Board of Health.
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The Ashland Board of Health
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unanimously endorses the E.P.A.'s preferred
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remedial action plan, RA-2.
In endorsing this
plan, the Board would like to note that if the
area in question is unpopulated or even populated
low density we would have endorsed plan RA-5.
It is the understanding of the Ashland
Board of Health that plan RA-2 calls for placement
of approximately five recovery wells, all within
the Megunko industrial area; that the product f~om
these wells will be piped to a central filtration
within the industrial area, and that the clean
discharge from that facility will meet drinking
water standards,
and be returned to the Sudbury
River.
The Ashland Board of Health, after
studying RA~4, cannot endorse the Board of
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It is the understanding of the Board of Health
that plan RA-4 will do all the features of plan
two,
plus it includes four wells in place in the
residential areas of Pleasant Street, Tilton Road,
Cherry Street and Water Street, and that 'the
contaminant will be taken by pipe from those wells
to the treatment facility in the industrial area.
Presently, monitoring wells have shown us the
highest level of contaminants in that area are 40
to 70 feet below the surface of the ground.
Monitoring in basements in that area indicated no
contamination of those basements.
Apparently,
that 40 to 70 feet of soil is protecting those
residents from the contaminated groundwater.
The
Board of Health does not feel that it would be
proper to bring that groundwater to ~he surface
and then pipe it in its contaminated form through
the residential area.
Even though the Board of Health
acknowledges that the E.P.A. and its contractors
will do everything in its power to prevent the
release of contaminants, either in liquid or in
gaseous state from the wells or from pipelines in
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leak does exist in the implementation of RA-4.
The Board of Health believes in Murphy's Law.
For
the record, Murphy's Law states very simply, what
can go wrong will go wrong.
I believe in
Fassler's Law, which for the record states Murphy
was an optimist.
In weighing RA-4~ you find that the
risks from the wells and the pipelines in the
residential area will not counter a slight
decrease in cleanup time, which is measured in
decades and hundreds of years.
We do not feel
that the decrease in cleanup time offsets an
increase in potential dangers to the residents of
that neighborhood having pipelines and wells in
their neighborhood.
In endorsing the E.P.A.'s remedial
action of RA-2, the Board of Health is only
endorsing the rough concept put forth within the
plan and ~rqes the E.P.A. to work closely with all
appropriate town departments when developing the
details of the design, bidding and construction
phases so that the problems similar to the
experience in Phase I are not repeated.
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HEARING OFFICER SHIELDS:
Okay.
That
is it for people who have signed up to speak.
I
understand that there are people who didn't want
to sign cards but still may want to get up and
speak.
So if people want to raise their hand or
whatever,
I will ask that you move up to the mike
and speak your name and any affiliation,
and then
speak your statement clearly.
Would anyone else like to make a
statement?
BARRY BRESNICK:
Good evening;
I am Barry Bresnick.
I, am the V ice
Chairman of the Board of Ashland Selectmen.
Again,
I want to thank you all for
coming out tonight and for holding this public
hearing on wha~ I think the Board of Selectmen and
the Board of Health would all agree is a very
positive proposal.
The Board of Selectmen have chosen to
make comments which are slightly different, but in
principle, I believe, very much the same as
Doctor Fassler.
We do support the fact that you
are interested in corning and continuing with the
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of which we may not all agree on 100 percent, but.
I think we are certainly in agreement 90 percent.
So I have a letter which I have drafted on behalf
of the Board of Selectmen, and it will be in the
mail most likely tomorrow to Mr. Lederer, and
basically what the letter does is recognize the
contribution of the E.P.A.
and various other
federal and state agencies towards the cleanup of
the Nyanza site, and in general in support of the
plan, certainly in principle.
Where we differ a
little bit from the Board of Health is that this
letter that I would like to read into the record
makes mention of the goals of the criteria which
the E.P.A. set up as what they wanted to
accomplish in this cleanup, and they were:
(1) To reduce migration of
contaminants in groundwater;
(2) Reduce risk to human health
associated with potential future consumption and
direct contact with groundwater;
(3) Reduce risk from present and
potential future inhalation of evaporated
groundwater contaminants;
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River and wetlands from the discharge of
contaminated groundwater;
And the fifth goal of your proposal
was to comply with state and federal applicable,
relevant and appropriate requirements,
including
drinking water standards.
In reviewing the five alternative
scenarios as outlined in the plan, the Board of
Selectmen supports in principle the E.P.A.'s
recommendation for a pilot program to treat the
groundwater contamination using the pump and treat
method.
We further support the five-year program
of evaluating the technology and performance of
the pump and treat method.
However, the Board of Selectmen
believes that the E.P.A.'s preferred alternative
two will not achieve the stated objectives as well
or as completely as alternative four or by an
expansion of alternative two.
Alternative two
will potentially over time effect and achieve each
of the five standard objectives, but not
throughout the entire contaminated area.
Alternative two will begin the long and difficult
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1
area, and it will effect approximately two-thirds
2
of the area.
However,
none of the five stated
3
objectives will be met either in part or in full
4
in the balance of the contaminated area.
5
It is the recommendation of the Board
6
that further consideration be given to an
7
expansion of the E.P.A.'s preferred alternative to
8
effect groundwater cleanup over the entire area of
9
contamination in an atte~pt to more fully achieve
its goals.
We do not recommend an evasive and
potentially disruptive alternative, as presented
in alternative five.
Perhaps just one or two
additional wells in the Forest Ave. or Tilton Ave.
area would more fully effect the cleanup,
be less
disruptive add a minimum of cost and more fully
realize each of the goals.
The Board of Selectmen, on behalf of
the the town~ wisheg to once again express our
thanks and support to the E.P.A. and others
involved in the Nyanza odyssey.
We look forward
to working cooperatively with the E.P.A. towards
the goal of continuing the cleanup of the Nyanza
site; and as I mentioned before, there may be some
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principle we are all very much behind you.
Thank you.
HEARING OFFICER SHIELDS:
Okay.
Is
there anyone else who would like to make a
statement?
Okay.
Well, I guess if there are no
further statements, I will close the hearing.
Thanks for. your participation, and I ask that
people who wish. to submit written comments make
sure they do so before the deadline of July 26.
Yes.
JOHN ELLSWORTH:
I would like to make
a comment.
HEARING OFFICER SHIELDS: Okay.
JOHN ELLSWORTH: I didn't think it was
going to go this quickly. My name is
John Ellsworth.
I am Chairman of the Board of
Selectmen in the Town of Ashland.
I just would like to sort of put a cap
on tonight and recognize individuals and maybe
more people with a little bit of history.
This
thing started in the late '70s, early '80s, as far
as Ashland was concerned through the efforts of a
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.a Cleaner Environment, and at times they were
pushing a very, very large boulder up a very steep
hill.
Until the Superfund types of things were
funded, were recognized as required, they were
following the Love Canal model, talking daily,
weekly, whatever Lois gives trying to get people's
attention, and slowly, but surely,things began to
come
around, and Superfund was finally voted.
The E.P.A. recognized Nyanza for what
it was in the Town of Ashland, and for what it was
not.
Because of Nyanza, there was sort a
collective sigh of relief breathe4 by a lot of
people.
I think most of the townspeople were
very, very pleased to see the E.P.A. come into the
town along with the D.E.P. and all the other
agencies that were involved.
I suspect at times,
for those who were
. involved in the process,
and now I think I am
understat1ng things just a little bit, that it may
have been an example of the democratic process
working at its best, but I have to believe that
those who were involved in some of the discussions
were probably dealing with excessive amounts of
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,of the process, and I would particularly like to
note two individuals who were deep into that
process,
Dave Lederer and Ira Nadelman.
These people stuck with it, basically
pushed the plans through, got the project onto
track,
answered our questions.
There were valid
questions raised and valid issues raised.
There
were issues raised by people who were concerned~
People had definite worries about the health of
themselves and their children, and I think that
these two gentlemen in particular,
but I think the
whole E.P.A. handled the process ,in what I have to
basically point out is an exemplary fashion.
I would like sincerely on behalf of
the town and Board of Selectmen to thank you two
gentlemen for what you have done for us.
I would
also like to just thank the E.P.A. for not
basically looking at Phase II and saying, hey,
it's way down in the ground.
We have to leave it
there, and we will go do something else.
It has been characterized as an
experiment~
I characterize it is an experiment
that is going to do good, because it is going to
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health "risk to the folks in the neighborhood, and
my reading of the plan and the other people who
have spoken tonight is that on balance it
is a
solid, good plan for the Town of Ashland.
For
that, we thank you very much.
We look forward to the process
proceeding,
and we look forward to the next phase
being implemented, and I personally would like to
lead this audience in a round of applause.
(Applause.)
HEARING OFFICER SHIELDS:
Okay.
Is
there anyone else who would like to submit a
statement?
Okay.
On that note, I will close the
meeting.
Again, if people want to submit written
comments,
they can do so.
They should do so by
July 26, and thank you very much for coming.
(Whereupon, at 7:30 p.m., the hearing
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C E R T I FIe ATE
I, Marianne Kusa-Ryll, Registered
Professional Reporter,
hereby certify the
foregoing to be a true and complete transcript of
the proceedings held at the Ashland High School,
Ashland, Massachusetts,. on Thursday, July 18,
1991.
~~~.4~.-f«1
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Nyanza chemical Waste Dump site Responsiveness summary:
Section V: written Comments Received During Comment Period
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'.
UW Offices of
. .
CATANZARO & EFFREN, P.C.
25 \\7~sr Union Sf,reet
&hLu1d, Massachusetts 01721
'"
. t Y'"I ,.
:';ac.: . .
Jerry C. Hfren
(508) 881-4950
FAX No.:
(508) 881-7563
o
Roscnury A. Bossclair
Ror~J M. SlUW:
..r~
.. j"11
U\!L .... 28 1991 ~
, .... ;
"
I'
FEDERAL EXPRESS
July 26, 1991
AlA S\.i?ERFU:.o SECT:'::14
Mr. David Lederer
Remedial Product Manager
U.S. ENVIRONMENTAL PROTECTION AGENCY
Wast Management Division (HRS-CAN2)
J.F.R. Federal Building
Boston, Massachusetts 02203-2211
RE:
NYANZA SUPERFUND SITE
ASHLAND, MASSACHUSETTS
Dear Mr. Lederer:
Enclosed please find comments on the Nyanza Operable Unit II
Report on. behalf of AIF Realty Trust and Environmental
Restoration Engineering Realty Trust.
If you have any questions, please do not hesitate to contact
me.
Very truly yours,
(
e ry fren, Attorney for
F Re y Trust and,
E viro mental Restoration
Engin ering Trust
JCE/dpm
Enclosures
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5.
6.
MEMORANDUM ON NYANZA II
TO: . ~ .
FROM:~~e C~~gis, Consultant to AIF Realty Trust and
Environmental Restoration Engineering Realty Trust
DATE:
July 26, 1991
RE:
Nyanza Superfund Site, Nyanza Operable Unit II Report
=================================================================
1.
AIF Realty Trust and Environmental Restoration. Engineering
Trust are hereby submitting comments on the Draft Final
Remedial Investigation Report, Nyanza II - Groundwater Study,
Ashland, Massachusetts, April 1991, (Nyanza II Report).
2.
These comments are based on review of Nyanza II Report, Volume
I and Volume II (Appendices). We would like these comments to
become part of the public comment records supporting a final
Record of Decision (ROD) on the Nyanza Operable Unit II
(groundwater contamination).
3.
We note the extensive geophysical and geological
investigations (Sections 2.0 and 3.0; Appendices), plus the
equally extensive investigation of the chemical contaminants
(Section 4.0; Appendices) in the groundwater and soil. It is
apparent that the groundwater contamination has migrated
beyond the Nyanza property boundary into what is called the
Nyanza Site Study Area, (Sections 4.0, 5.0 and 6.0).
4. . With some exceptions, most of the oganic chemicals (volatiles
and semivolatiles) are below the 1-10 ppm concentration range
in the groundwater (sections 4.0 and 5.0). Metals, especially
chromium, lead and mercury, are also present in significant
levels in the study area. The assessment that sodium may act
as a conservative indicator of contaminant migration (Section
5.0) is noted.
The possibility that bedrock and surficial geological
compartments may act as sources of contaminants following
remediation of site-specific contaminant sources (e.g.,
Megunko Hill, vault area) is also noted. These findings have
significant implications on the costs and timetables for
potential remediation strategies.
The Nyanza II Report indicates that there is time overlap
between the implementation of the Nyanza Operable Unit I
remediation schedule and the Nyanza Operable Unit II
investigation. We would like to review any additional future
assessments of the effects of Nyanza I remediation actions on
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\)
7.
We would like an opportunity to review the companion reports
on risk assessment and the feasibil~ty study. In particular,
we would like to review cost/benefit analyses of various.
remediation alternatives in relation to the human health risk
assessments.
8.
It is now clear that Nyanza I, II and III will be a very
costly and long remediation program. consequently, we are
C'0!'1~t?!"J'1E"d with the optimization of the cost/benefit
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Katherine H. Narn
202I8S7-6081
1050 Connecticut A value, 110"1'
Vuhington.. DC 20036~5339
Telephone; 2021857.6000
Cable: ARFOX
Te1ea: WU 892672
117 +t0266
f acaimile: 2021857 -6395
'4'5 "isconsm Avenue
Bethesda. MIU')'land 20814.3413
8000 Towen u-t Drive
Vienna. Virginia 22182.2733
Arent Fox Kintner Plotkin & Kahn
July 26, 1991
imrn @ rnO\Y1 1m
Ie '. WJ HI8S1 !UJ
L '.,...- t.,,.- -',
'"' -"'. ..'
--.. ~--
VIA CERTIFIED MAIL
Mr. David Lederer, Remedial Project Manager
U.S. Environmental Protection Agency
Waste Management Division (HRS-CAN2)
J.F.K. Federal Building
Boston, Massachusetts 02203
Re: Nyanza' Superfund Site, Ashland, Massachusetts
Cleanup Alternatives for Groundwater Remediation
Dear Mr. Lederer:
On behalf of Rohm Tech, Inc., enclosed are our comments to EPA's
preferred alternative, as well as the other cleanup alternatives under
consideration, concerning the groundwater remediation at Nyanza. These
technical comments have been prepared by AFTECH Limited Partnership,
an environmental consulting firm, which reviewed the cleanup alternatives.
We look forward to EPA's response to our comments.
Sincerely,
I~L'~'JV~JcH,j
Marc L. Fleischaker
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~ITECH
~
COMMENTS TO PROPOSED PLAN
NYANZA SUPERFUND SITE
These comments were developed from a review of the
EPA Region I Summary of the Proposed Plan for the
Nyanza Chemical Waste Dump Site, Ashland, Massachusetts,
dated June 1991, Summary document.
1.
Pump-and-Treat Techn010QY
In general, all of the cited "options" for interim
action are merely different versions of ~he same plan (i.e.,
pump-and-treat), with varying locations and numbers of
extraction points. The National Oil and Hazardous Substances
Pollution Contingency Plan ("NCP"), at 40 C.F.R.
S 300.430(e)(4), provides that with regard to ground water
response actions, the lead agency shall develop a limited
number of remedial alternatives tha~ attain site-specific
remediation levels within different restoration time periods
utilizing one or more different technologies. .
Since pump-and-treat technology has yet to succeed in
"cleaning up" any Superfund site ground water down to federal
drinking water standards ~/, such a cleanup cannot be
regarded as achievable using this technology. The sole
objective should therefore be the prevention of the spread of
the contamination plume (i.e., control versus remediation)
and a general overall reduction in the level of toxics in the
plume. The regulations require the lead agency, in regard to
source control actions, to develop where appropriate
alternatives that involve little or no treatment, but provide
protection of human health and the environment by preventing
or controlling exposure to hazardous substances through
engineering controls such as containment. 40 C.F.R. S
300.430(e)(3)(ii). This requirement deserves further
consideration and review. If there is no proven applicable
technology which is more effective than pump-and-treat in
five years (and there currently is no strong indication that
there will be), it is highly unrealistic to expect that a
"final decision" regarding remediation to MCL levels could be
reached at that time.
Mor~over, over time, pump-and-treat systems may
result in an initial reduction in contamination, followed by
1/ Travis, C.C. and Doty, C.B. (1990): "Can
contaminated aquifers at Superfund sites be remediated?"
Environ. Sci. Technol. 24, 1464-1466.
AFTECH Limited Partnership
Suite 450 . Washington, D.C.
1050 Connecticut Ave., N.W.
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~ITECH
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- 2 -
a plateau~/. A return of contamination to initial or even
higher levels has been known to occur when the system ceases
operation~/. This possibility does not appear to have been
adequately considered in the Feasibility Study. Based on the
contaminants identified, many of which are nearly insoluble
nonaqueous-phase liquids (NAPLs), and the fact that the
overall quantity of these NAPLs released is not clearly
known, such a situation is a distinct possibility for the
site. Perhaps the "decades to centuries" cleanup estimate
alludes to this factor. If so, this should be a predominant
factor in the system design and more reason to have plume
containment rather than aquifer restoration as the primary
objective. . .
Given the above considerations, there does not seem
to be ample justification for an interim 5 year pump-and-
treat program versus, for example, a 2-3 year program.
Specifically, it is not apparent that 5 years of operation
will have a more permanent effect than 2-3 years. The
information does not show that the goa1 of .'control and
containment" necessitates 5 years, nor does it indicate that
the agency has truly considered whether this is a more
realistic approach.
...
Finally, section 300.430(e)(S) of the NCP provides
that one or more innovative treatment technologies should be
considered if those technologies offer "the potential for
comparable or superior performance or implementabilitYi fewer
or lesser adverse impacts than other available approaches; or
lower costs for similar levels of performance than .
demonstrated treatment technologies." In light of the
ineffectiveness of the pump-and-treat technology for the
remediation of ground water, the information reviewed for the
Proposed Plan does not mention whether other so-called
innovative technology (e.g., bioremediation) might be used
independently or in conjunction with pump-and-treat.
2~
Ground water Cleanup Standards
It is not clear why the ground water cleanup
standards are set at federal drinking water levels when the
~/ Mackay, D.H. and Cherry, J.A. (1989): "Groundwater
contamination: Pump-and-treat remediation", Environ. Sci.
Technol. 23, 630-636.
3/ "Evaluation of Ground-Water Extraction Remedies",
USEPA OSWER (1989) EPA/S40/2-89/0S4, Vol. 1, pp 2.14.
AFTECH Limited Partnership
Suite 450 Washington, D.C.
1050 Connecticut Ave., N.W.
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water is not used for drinking or even for recreational
pur~",::.~:;.. ~~;.;c..1.on 300.430(e)(2)(i)(B) states the following:
"Maximum contaminant level goals (MCLGs), established under
the Safe Drinking Water Act, that are set at levels above
~~~~, s~~ll ~ ~~tained by remedial actions for ground or
surface waters that are current or potential sources of
drinking water, where the MCLGs are relevant and appropriate
under the circumstances of the release. . . ". Section
300.430(e)(2)(i)(C) states: "Where the MCLG for a
contaminant has been set at a level of zero, the MCL
promulgated for that contaminant under the Safe Drinking
Water Act shall be attained by remedial actions for ground or
surface waters that are current or potential sources of
drinking water, where the MCL is relevant and appropriate
under the circumstances of the release " Since the
ground water at the site is not currently used and has little
to no potential to be used in the future for drinking water
(particularly considering the other industrial operations in
the area), the federal drinking water standards should not be
applied to the remediation goals.
Furthermore, since even the Feasibility Study accepts
that "it may take many decades to centuries of treatment" to
achieve these federal drinking water levels, ~his statement
implies that such levels are, for all practical p~rposes,
unachievable using current technology. Thus, the distinction
between "centuries" of treatment (at great cost) and
"thousands of years" of non-treatment/natural flushing is
academic at best, if not highly speculative.
3.
Risk Analysis
The NCP provides generally that "[r]emediation goals
shall establish acceptable exposure levels that are
protective of human health and the environment. . . .. 40
C.F.R. S 300.430(e)(2)(i). Again, since there are no private
or public drinking water supply wells in the vicinity, the
current risk to h~an health from contaminated ground water
is minimal. Therefore, it does not make sense that the
proposed cleanup objectives include reduction in "risks to
human health associated with potential future consumption and
di.""!:,r.-+ "/"'\~:pct with ground water" when there is no reason to
expect any requirement for such future consumption. Human
exposure can be further controlled by deed restrictions and
water use controls. .
The Risk Analysis determined that health risks from
ground water seepage into basements was minimal, and implied
AFTECH Limited Partnership
Suite 450 Washington, D.C.
1050 Connecticut Ave., N.W.
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~ITECH
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that other health risks only arose if the water became a
source of household supply (which is not anticipated).
Moreover, it is highly speculative to determine what exactly
are the true "risks from present and future inhalation of
evaporated ground water contaminants" and the probability of
such exposure ever occurring especially since exposure would
be in open areas. The risks appear to be minuscule at best,
if not ~aginary.
In general, the information reviewed in the Risk
Analysis does not support the preferred option nor any of the
other options. EPA appears to have conducted a rather flawed
evaluation process with their Analysis conflicting with their
recommended actions. Perhaps the agency was motivated by its
perceived need to have to "do something", and by local
pressures.
4.
~
Using the information reviewed, the proposed costs
for installation and operation of the pump-and-treat system
appear to be high. Moreover, the time to design and install
the system also appears 1engthy~ Section 300.430(e)(7)(iii)
provides that cost shall be a factor in considering the
remedial alternatives. "Costs that are grossly excessive
compared to the overall effectiveness of alternatives may be
considered as one of several factors used to eliminate
alternatives." In light of the highly questionable long-term
effectiveness of pump-and-treat technology for this site, the
costs for installing and operating this system for an
excessive period of time raise additional questions about the
selection of the preferred alternative.
AFTECH Limited Partnership
Suite 450 Washington, D.C.
1050 Connecticut Ave., N.W.
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July 19, 1991
MA ~-m:T'DN
David ~ederer, Remedial Project Manager
U. S. Env~ronmenta1 Protection Agency
Waste Management Division
JFK t'ederal Building (HRS-CAN 2)
Boston, MA 02203
L_--
Co~~ent/Question - Nyanza Operable Unit 2 - Groundwater
Cleanup
Does the EPA intend to add the landowners to the PRP list who
own property within the "Nyanza Contaminant Groundwater Plume"
as shown on Figure 3 of EPA's June 1991 Proposed Cleanup Plans
for Operable Unit 2? Why?
Re:
Sincerely,
aUUlt'AJAt«.,
Claudia Lefter
165 Fountain St.
Ashland, MA 01721
EPA Figure 3 Attached
Reference: Section 107(a)(l) of CERCLA - imposes liability for
response costs on owners or operators of "facilities" from which'
there is a release or threatened release of a hazardous substance.
A "facility" is defined under Section 101(9) as including,
among other things, any building, structure, equipment, pit,
pond, storage container, motor vehicle, etc., and any "area
where a hazardous substance has been deposited, stored, disposed
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N
SEDIMEHTAnON
BASIN
MEGUNKO HIlL
AREA
,Y
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LEGEND
FIGURE 3
GROUND WATER
AND SURFACE WATER
DIVERSION TRENCH .
APPROXIMATE PLUME BOUNDARY
WETlMDS
n
~
B
NYANZA CONTAMINANT
GROUNDWATER PLUME
I~OOKS/STREAMS
NOT TO SCAlE
SHEET 1 OF 1
.'.
(
(
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~ M. D:.r.L..Wlj~
FOR
t..TILLIA~ M. LEACU
BOX 182
ASHLAND, NASS. 01721
DA'v W .".1:...../1...-"""" -~ '1.:.J..;.I.rU.. PROJECT MANAGrn
U. S. ENVIRO~1\fl-.7AL PRCYTECTION AGENCY
WASTE MANAG.EMEt\'T DIVISION(HRS CAN 2)
r r "---: ~. -r
.. ,
i . .w. 2 J & 1991 'l
I-u ~'
AlA:. . -"'~ £:::": .! t
JFK n:"T"\r'D" 'Df T'TT T'lT"Tf"
" !. ~_w - --..-.....,""
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On July 27th, 1991, the public comment period will close for
the Interim Groundwater Cleanup Plan, Operable Unit 2, Nyanza
Superfund Site, Ashland.
Operable Unit 2 is designed to treat the contaminated ground-
water plume as depicted in EPA Proposed Plan, "EPA Proposes Cleanup
Plan for the Nyanza Chemical Waste Dump Site", June 1991.
Since the groundwater plume covers approximately 1/2 mile
east and northeast of Megunko Road (which includes all of the
land adjacent to the following streets, Metcalf, Forest, Tilton,
and Water Streets, and portions of Pleasant, Myrtle and Main Street)
we respectifully submit that all landowners within the boundardies
(as shown on the enclosed EPA Figure 3, Nyanza Contamnant Ground-
water Plumel be added to the current PRP list as Operable Unit 2
is solely for the remediation of groundwater clean up activities.
Also, please note, you may also want to add Concord Street now affected by the
Toxic Plume according to the newest EPA Diagram, and The Town of Ashland, as diagram
shows Plume to be under the Ashland Town Hall, Ashland Police, and the Ashland
Fire Station.
Sincerely,
Barbara A. Beaudoin
~6 'r~rca.
\.'
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SEDIMENTATION
BASIN
MEGU';KO HILL
AREA -
t::f?
rc
~
LEGEND
FIGUHE 3
- GROUND WATER
AND Sl RFACE WATER
DIVERSION TRENCH
APPROXIMATE PLUME BOUNDARY
~.
~
~
~
NYANZA CO.tITAMINANT
GROUNDWATER PLUME
WETlANDS
BROOKS/STREAMS
NOT TO SCALE
SHEET 1 OF 1
(
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v
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if)
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Mr. David Lederer
V.S Environmental Protection Agency
Waste Management Division (HRS-CAN2)
JFK Federal Building
Boston, MA 02203
~D rn@GD~Jl'- r:„\
- 'I~
. ,
~\ WJ ZI 1981- ~
MA SUPERFUND SEeTON
JUly 24, 1991
Dear Mr. Lederer,
I am writing to express an important..:.ccncern r~have regarding
the Nyanza Chemical Waste Dump Site in Ashland, Massachusetts.
I believe that the cleanup plan is very import'ant since we
would all like to have clean water and air. However I do
have some concerns regarding who is responsible for the cost
of implementing one of the plans outlined in the June, 1991
proposal.
It is my understanding that the EPA would like to collect from
"PRP's" the cost of cleaning up Nyanza~ 1 would like to know
if the Town of Ashland falls under this category. Mr. Martin
Mulhall was at one time the plant manager for the Nyanza .
Chemical Company. At the same time he was also Chairman of the
Asland Board of Selectman and on the Ashland Board of Health.
I believe this represents a conflict of interest in that while
Mr. Mulhall received constant complaints about the chemical
company, he also had a personal interest in not pursuing these
complaints. Will there be any liability for the costs of
cleaning Nyanza to the Town of Ashland? Has this issue been
investigated?
If there is the possibility that the Town of Ashland may be
responsible for the cost of the cleanup, I think it is important
to make the citizens of Ashland aware of this so that they can
make a better informed decision on which plan they would like
to implement.
SiC~. ~ ~
Cynthia J. Leacu
-------
:~~@~01
'
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-2-
5. Comply with state and federal - applicable, relevant and
appropriate requirements (ARAR) - including drinking
water standards.
In reviewing the five alternative scenarios as outlined in the
plan, the Board of Selectmen supports in principle the EPA's
recommendation for a pilot program to treat the groundwater
contamination using the "pump and. treat" method. We further.
support the five year program of evaluating the technology and
performance of the pump and treat method.
However, the Board of Selectmen believe that the EPA's preferred
alternative 2 will not achieve the stated objectives as well or
as completely as alternative 4 or by an expansion of alternative
2. Alternative 2 will potentially, over time, effect and achieve
each of the .five stated objectives but not throughout the entire
contaminated area. Alternative 2 will begin the long and
difficult task of cleansing the most heavily contaminated area
and will effect approximately two-thirds of the area. However,
none of the five stated objectives will be met either in part or
in full in the balance of the contaminated area.
It is the recommendation of the Board that further ~onsideration
be given to an expansion of EPA's preferred alternative to effect
groundwater cleanup over the entire area of contamination in an
attempt to more fully achieve its goals. We do not recommend an
evasive and potentially disruptive alternative as represented in
alternative 5. Perhaps just one or two additional wells in the
Forest Avenue or Tilton Avenue area would more fully effect the
cleanup, be less disruptive, add a minimum of cost and more fully
realize each of the goals.
The Board of Selectmen, on behalf of the Town, wishes to once
again express our thanks and support to the EPA and others
involved in the Nyanza cleanup odyssey. We look forward to
working cooperatively with the EPA towards the goal of continuing
the cleanup of the Nyanza site.
Sincerely,
J300F s~
Barry -;:'Jnick
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,.
r=~~
GORDON - MINDICK PROPERTLl&~ .1991
- . I
p.o eo": "Ioe . , 0 MAIN STREET. ASHLAND. MASSACHUSETTS
U2'. . (508) 881 .484~ .-
July 18, 1991
cJo
Based upon our attendance at the regularly scheduled
meetin9s. the information distributed at the June 26
meet1ng, and the physical location of the plume, it is our
opinion that Alternative RA-S be implemented.
The summary of comparative analysis of alternatives
presented at the June 26 meeting indicated nine criteria
were used to evaluate each remedial alternative. The nine
criteria, in our opinion, indicate that Alternative RA-S
should be the preferred alternative. .
Listed below: using your own criteria, are the reasons we
want. the entire plume cleaned.
1.
Overall protection of human health and the environment.
Although your report states that "RA-2, RA-4 and RA-S, when
viewed as i~terim remedies, would provide similar
information leading to the choice of a final remedy. It
also states "over a five year period, alternative RA-S
would provide the most effective removal of contaminants,
because wells would be placed at many locations throughout
the study area."
2. Compliance with applicable or relevant and appropriate
requirements (ARARs).
"Alternatives RA-2 through RA-S would meet ARARs ...
"
3.
Long-term effectiveness and permanence.
Not .relevant.
4.
Reduction of toxicity, mobility or volume.
If alternatives RA-2 through RA-S all reduce toxicity,
mobility, and volume of organic contaminants; and
alternative RA-2 reduces the toxicity, mobility and volume
cf :!.~~~~~ ~=~pounds less than alternatives RA-3, RA-4 and
RA-S, because it treats a smaller portion of the entire
plume; and if RA-2 is superior to RA-3 since it attempts to
capture contaminants closer to their source: then RA-S must
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GORDON - MINDICK PROPERTIES
P.O. BOX 409 . 10 MAIN STREET. ASHLAND. MASSACHUSETTS 01721 . 15081 BB 1.4B40
5. Short-term effectiveness.
RA-l would pose the least short-term risk of adverse
impacts on human health and the environment. RA-2 would be
constructed primarily in an area zoned industrial and RA-5
would pose the greatest risk because of the numerous wells
located in residential areas
6. Implementability.
RA-l is obviously the easiest to implement. "The various
components of Alternatives RA-2 through RA-5 are common
elements of remedial projects that could be readily
implemented." "RA-2, with it focus primarily in an
industrial area, would cause the least such disruption."
RA-S would cause the greatest disruption because of its
many locations.
The residential area concerns presented in the short-term
effectiveness and implementability criteria would be
mitigated by using other available industrial and/or
residential B land, located on the plume. Gordon-Mindick
Properties could make available land and/or buildings that
would allow for the effective removal of contaminants from
the entire plume in an area that would cause the least
amount of disruption to a residential area.
...
If the goal is to extract and treat contaminants in an
industrial area, because the least amount of disruption
would occur, then the offer of Gordon-Mindick Properties
should allow for the full clean up of the plume.
It is our hope that your consideration of our comments and
offer will prompt you to modify or select another preferred
al terna-tive.
J 1 Silverstei
f r Gordon-Mindick Properties
-------
~, I -;',
I ;: ~
~ ,
. I .
r. I ~ 1 8 1991 ;
The Ashlend Boerd of Heelth unenimously endorses the EPA's pJ~f~rred remediel:~:~~lpl~n.
RA2. In endorsing this plan the Boerd would like to note that~tf-the 8re8-4n~ . was
unpoDuloted or eyen populated in low density we would hoye endorsed plen RA5.
~~-.~
o
It is the understanding 01 the Ashland Board 01 Heatth that plen RA2 cells for the plecement
01 approximately 11ye (5) recovery wens, 811 within the Hegunko industriel eree; th8t the
product from tnese we:is wiil be piped to central ft1trat10n fac11ity within the industrial
area, and that the cleen discharge from this facUity w111 be released into the Sudbury RiYer.
It is further understood thet the plecement of the recovery wells w11l be such. that the draw
will not only. be from the industriel area, but will include contaminated waters from
beneeth the adjecent residential eree.
The Ashland Board of He8tth, after studying p1en RA4, cennot endorse the Board of
Selectmen's call for the implementetion of that plen of remedial ection. It is the
understanding of the Board of Heatth, that plan RA4 includes al1 the features of plen RA2
plus the placement of approximately four (4) additional recovery wens in the residential
arees of Tilton Avenue, Ctlerry Street, P\eez6nt Street, and Water Street, end the piping of
the contaminated product from these wells through that residential neighborhood to the
treatment fecl1ity within the industriel eree.lt is. further understood by the Boerd of Heatth
Hlet the most highly conteminated ground water in thet residential erea is found et a depth
of between forty (40) end seyenty (70) feet below the surfece end thet samp1ings of eree
besements have proven negative to contamination. Apparently, that thickness of so11
between the residents and the contaminants are protecting the residents from the effects
of the contaminants. Remedial Action Plan 4 would bring this contaminated water from this
protective depth to the surfece and then run it through the densely populated residential
erea 1n p1pes that would be eppro)(imately four feet below the surfece. .
Atthough the Board of Health acknowledges that the EPA and its c.ontractor
-------
July 9, 1991
, ..'.-: [I~(~fI))
-_.JJ. f 8 1991 }~
'.:.~! ~:~:"'.':: S:=T::~t
United States Env'::>nmental Protection Agency - Region I
Attn: Mr. D. Lede~,.r - Remedial Project Manager
Waste Management Division
JFK Federal Building (HRS - CAN 2)
Boston, MA 02203
.- - . ,
..
Dear Mr. Lederer,
My wife and I are writing this letter to your agency to comment on your Phase
II plan to clean up the ground water and to comment re the actions taken to
this point in cleaning up Nyanza.
Phase II - we arc very pleased that the EP A has decided to work on the
groundwater situation. While we conclude that the health risk to individuals
from groundwater contamination is low, we believe that the potential for
future risks warrants investigating remediation alternatives. It appears that the
clean-up measures you arc recommending arc conservative and in the interests
of the. town as a whole. Even jf not totally effective, the attempt is being
made and knowledge is being gathered. And the best news of all for Ashland
is that "Nyanza is being fixed" in the process.
Phase I - We would like to commend your agency on way it has pursue-d the
correction efforts. This has not been an easy job. At times it seemed that the
vadous town entities were actively blocking action at the site,
We particularly want to note two individuals, who have made important
contdbutions to the process of arriving at near completion for Phase I: ~
Letterer and Ira Nadelman. These gentlemen persevered and were able to
effect accommodation between what were at times wardng factions. It is a
tdbute to their abilities that the project has arrived at its current state of
completion. It is also a fair statement to say that the history of this project is a
good example of the democratic process working, and working well. It may
have at times been a painful experience for these men, but they attained the
goals under its pressure. Please have these comments recorded in the record of
work for this project and communicate them to David and to Ira. Thank you.
Sincerely yours,
Margot Ellsworth
John Ellsworth
PO Box 293
-------
APPENDIX II:
.v
£J
-------
Commonwealth of Massachusetts .
Executive Office of Environmental Affairs
a Department 0'
J' 1 Environmental Protection
Daniel S. Greenbaum
CommiSSion.'
September 23, 1991
Ms. Julie Belaga
Regional Administrator
u.s. EPA Region I
JFK Federal Building
Boston, MA 02103
RE:
Nyanza Chemical Waste
Dump Federal Superfund
Site - Operable Unit Two
Groundwater Contamination
ROD Concurrence
Dear Ms. Belaga:
The Department of Environmental Protection (the Department)
has reviewed the preferred remedial action alternative recommended
by EPA for Operable Unit Two, groundwater contamination, at the
Nyanza Chemical Waste Dump Federal Superfund Site. The Department
concurs with EPA' s selected remedy which implements an interim
remedy.
While the Department agrees with the need for additional
information in order to select a final remedy, the Department is
requesting EPA to consider expanding the extraction system to
include the eastern portion of the plume prior to the issuance of
the final ROD if additional studies indicate groundwater recovery
is feasible. This request is consistent with a recent OSWER.
Directive ("Considerations in Ground Water Remediation at Superfund
Sites") which recommends that based on data gathered during the
initial operation of a recovery system, the system could be
modified and expanded as part of the remedial action phase to
address the entire plume in the most efficient manner.
The Department has evaluated EPA's preferred alternative for
consistency with M.G.L Chapter 21E and the Massachusetts
contingency Plan 310 CMR 40.00 (MCP) and has determined that EPA's
selected remedy is consis~ent with the requirements of the MCP. The
Department accepts the phased implementation of a temporary and
permanent solution provided that the temporary solution be
effective until a permanent solution is implemented, include
One Winter Street
.
Boston, Massachusetts 02108
.
FAX (617) 556-1049
-------
<.J
Nyanza ROD Concurrence
Belaga
September 23, 1991
Page 2
o
systems to monitor its effectiveness, and facilitate a permanent
solution. Ho~ever, a permanent solution determination cannot be
made until it has been demonstrated that the remedial measure or
combination of measures will meet the Total Site Risk Limits as
defined in 310 CMR 40.00 for the entire site.
The Department generally identifies the MCP as an applicable
requirement for sites in Massachusetts while reserving the right
to argue that Chapter 21E constitutes an independent enforcement
authority that is not subject to the waiver provisions of CERCLA
section 121 (d) (4). The Department identifies the MCP and Chapter
21E as applicable requirements, within the meaning of CERCLA, for
Operable Unit II of the Nyanza Chemical Waste Dump Federal
Superfund site.
The selected remedy appears to meet all Massachusetts state
ARARs. This will continue to be evaluated as remedial design
progresses and during implementation and operation.
The Department looks forward to working with you in
implementing the preferred alternative. If you have any questions
or require additional information, please contact Charla Reinganum
at 292-5826.
J42~
Daniel S. Greenbaum, Commissioner
Massachusetts Department of
Environmental Protection
-------
APPENDIX III:
1990 DATA
,
ESTIMATED GROUNDWATER CONCENTRATIONS DERIVED FROM 1988 AND
-------
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------- |