United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-92/080
March 1992
SEPA Superfund
Record of Decision:
Rhone-Poulenc/Zoecon, CA
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--===
NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement, but adds no furtherapplicabJe information to
the content of the document. All supplemental material is, however, contained in the administrative record
for this site. .
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50272-101
REPORT DOCUMENTATION 11. REPORTNO.
PAGE EPA/ROD/R09-92/080
4. TIde and Subti1le
I~
3. Recipient'. A=e881on No.
5. Report Date
SUPERFUND RECORD OF DECISION
Rhone-Poulenc/Zoecon, CA
First Remedial Action - Final
7. Aulhor(s)
03/04/92
6.
8. Performing Org8tlzallon Rept. No.
9. Performing Orgalnlzation Name 8M! AcIdr-
10. ProjectlTakIWorit Unit No.
11. Contrac1(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Addr-
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & PerIod Covered
Agency
800/000
14.
15. Supplementary Notes
PB93-964503
16. Abstract (Urnlt: 200 words)
The 13.19-acre Rhone-Poulenc/Zoecon site is located in East Palo Alto, San Mateo
County, California. The site is composed of at least 12 separately owned parcels that
include a 5.19-acre former pesticide manufacturing plant, a sludge pond, and a
chemical storage facility owned by Sandoz Crop Protection Corporation. From the late
1950's to the early 1970's, another parcel at the site, called the Call-Mac Property,
was used to store hazardous waste drums some of which were leaking. Land use in the
area is mostly industrial with some mixed commercial and residential use within
one-fourth mile of the site. The site is located approximately 2,000 feet from San
Francisco Bay within the 100-year coastal floodplain, and is bounded on the east and
southeast by tidal and nontidal marshes (wetlands). Surface and subsurface drainage
affect surface and ground water that has numerous existing and potential beneficial
uses. From 1929 to 1972 until Zoecon Corporation purchased the site, pesticides
containing arsenic were manufactured and packaged onsite. In 1980, an investigation
by the new site owners revealed severe contamination of soil and ground water with
arsenic, which resulted from improper handling of pesticides during unloading. In
1981, the state directed the removal of 1,300 drums and 25 cubic yards of contaminated
(See Attached Page)
17. OocumentAnalysis a. Descriptors
Record of Decision - Rhone-Poulenc/Zoecon, CA
First Remedial Action - Final
Contaminated Media: Soil, gw
Key Contaminants: Metals (arsenic)
b. IcIentifierslOpen-Ended Terms
Co. COSA 11 FJeld/Group
. a. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
N()n~
21. No. of Pages
122
I
n Price
See ANSI-Z39.18
See Instructions on Reverse
272(4-77)
(Formerly NTlS-35)
Department of Commerce
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EPA/ROD/R09-92/080
Rhone-Poulenc/Zoecon, CA
First Remedial Action - Final
~stract (Continued)
soil from the Call-Mac Property. From 1985 to 1987, ground water monitoring wells and
fencing around contaminated soil were installed. In 1991, the state required removal of
approximately 4,000 cubic yards of contaminated soil; however, the Sandoz parcel is
currently a state-permitted RCRA facility for the storage and disposal of hazardous
wastes. This ROD addresses the contaminated soil and ground water in the upland
operable unit. A future ROD will address remediation of the wetlands operable unit.
The primary contaminants of concern affecting the soil and ground water include arsenic,
mercury, selenium, lead and cadmium.
The selected remedial action for this site at the Sandoz and Bains properties includes
removing and disposing of offsite soil from accessible areas with arsenic levels greater
than 5,000 mg/kg and installing a cap; for properties other than Sandoz and Bains,
removing or paving over soil with arsenic greater than health-based levels of 70 mg/kg
with deed restrictions on paved areas; for the whole site, treating soil contaminated
with arsenic levels between 300 and 5,000 mg/kg onsite using silicate stabilization;
excavating and treating contaminated soil from beneath onsite structures after
demolition; installing a slurry wall and dewatering around an area of approximately
76,800 cubic yards of soil containing arsenic-contaminated soil and ground water;
installing a cap and liner; monitoring ground water with a contingency that, if arsenic
exceeds 40 ug/l in perimeter wells or exceeds background levels in the deep aquifer,
ground water treatment will be performed; and implementing institutional controls
including deed restrictions for the Sandoz and Bains properties. The estimated present
worth cost for this remediation is $9,100,000, which includes a total O&M of $1,100,000
"'or 30 years.
PERFORMANCE STANDARDS OR GOALS: The chemical-specific clean-up standard for soil is
based on the health-based standard for arsenic 300 mg/kg. Ground water is based on
state and SDWA MCLs for arsenic 50 ug/l.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco,. Ca. 94105-3901
RECORD OP DECISION
PART I:
DECLARATION
PART II:
DECISION SUMMARY
PART IJ:I:
RESPONSIVENESS SUMMARY
RHONE POULENC/ZOBCON/SANDOZ
. SUPBRFUND SITE
BAST PALO ALTO, CALJ:FORNJ:A
KARCH 4, 1992
u. S. ENVIRONHEHTAL PROTECTION AGENCY
REGION 9
Prlnud 011 Recycled Paptr
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
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DECLARATION
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CONTENTS
PART
SECT:ION
PAGE
PART I: DECLARATION
I 1.0 site Name and Location l'
I 2.0 statement of Basis and Purpose 1
I 3.0 Assessment of the Site 2
I 4.0 Description of the Remedy 2
I 5.0 Statutory Determinations 3
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
DBCLARAT1:0H
1.0
S1:TB HAHB AND LOCAT1:0N
RHONE POtJLDC/ (ZOSCON) SANDOZ
SAN MATEO COUNTY
1990 Bay Road
East Palo Alto, California
:.t
2.0
STATEMENT OJ' BAS1:S AND PURPOSB
This Record of Decision ("ROD") presents the selected
remedial actions for the Rhone Poulenc/(Zoecon)Sandoz Superfund
site in East Palo Alto, California. This document was developed
in accordance with the Comprehensive Environmental Response, Com-
pensation, and Liability Act of 1980 (CERCLA) as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA), 42
U.S.C. section 9601 et. sea.. and to the extent practicable the
National Oil and Hazardous Substances Pollution Contingency Plan,
40 C.F.R. Section 300 et. sea.. ("NCP"). EPA issues this Record
of Decision pursuant to section 104 of CERCLA, and has selected
the remedial action in accordance with section 121 of CERCLA. - As
provided in section 121 (e) (i) of CERCLA, no federal, state or
local permit shall be required for the portion of any remedial
action conducted entirely onsite, when such remedial action is
carried out in compliance with section 121. This is considered
an Operable Unit Record of Decision. Investigatory work related
to this site is ongoing, and could potentially lead to additional
CERCLA actions, or actions pursuant to other statutory authority,
at this site. This decision is based on the administrative
record for this site. .
The State of California concurs with the selected remedy.
PrintH on Recycled Paper
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3.0 ASSESSMENT OF THE SITE
Actual or threatened release of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial en-
dangerment to public health, welfare, or the environment.
4.0 DESCRIPTION OP THE REMEDY
The remedial actions address a principal threat at the Rhone
Poulenc/(Zoecon) Sandoz site by treating the highly-toxic source
materials that are present in soil thereby significantly reducing
the mobility and/or volume of hazardous substances in the media.
The toxicity of arsenic would not be changed by this particular
treatment process.
This action represents the final remedial action to remove
contaminants from soil in the Upland Operable Unit. The selected
remedy for the site is Alternative £ described in the Remedial
Investigation/Feasibility Study and Proposed Plan. It will take
approximately 9 months to complete the soil stablization work and
the estimated cost of the remedy is $9,100,000. The major com-
ponents of the selected remedy shall include the following:
o institutional controls (deed restrictions) prohibiting
future residential use of the Sandoz and Bains
properties;
o excavation of soils containing arsenic concentrations
greater than 5000 mg/kg (excavation in accessible areas
occured during September 1991). Soil having arsenic
concentrations greater than 5000 mg/kg in the operating
portions of the Sandoz plant and beneath structures on
the Sandoz and Bains properties shall be excavated when
the facility ceases operation and structures are
demolished;
o excavation and/or paving of soils having concentrations
above health-based cleanup standards (> 70 mg/kg As)
on all properties except for Sandoz and Bains. In-
stitutional controls (deed restrictions) prohibiting
future residential use shall be obtained for properties
where paving is selected;
o treatment of soils containing arsenic concentrations
greater than 500 mg/kg arsenic using a silicate stabi-
lization technology. When contaminated soil located
beneath buildings is accessible, this contaminated soil
shall be treated using the same remedial standards
listed above.
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continued annual groundwater monitoring of perimeter
wells with a contingency plan for plume containment
should further migration occur. The details of the
contingency plan are outlined in the following reports:
Deep Aquifer Monitoring Plan, Revised Sampling and
Analysis Plan, and the Aquifer Contingency Plan. The
contingency plan requires groundwater extraction and
treatment if statistically significant evidence shows
that any one of the perimeter wells exceeds 40 ppb of
arsenic, or that the arsenic concentration in the deep
aquifer exceeds background levels.
installation of a slurry wall with dewatering. The
slurry wall shall surround the area containing con-
taminated soil and ground water remaining after soil
remediation. It will enclose 76,800 yd3 of soil (84%
of the contaminated soil in the upland operable unit)
and 43,200 kg of arsenic (58% of the arsenic).
Groundwater extraction and treatment within the slurry
wall is necessary to maintain the inward hydraulic
gradient across the slurry wall. Based on currently
available technologies, extracted groundwater shall be
treated in a precipitation/microfiltration process.
installation of additional deep aquifer monitoring
wells. The site shall contain a minimum of three well
pairs that will monitor the upper shallow zone, the
lower shallow zone, and the deep aquifer zone;
installation of a cap and liner on the currently un-
paved portions of the Sandoz property, the Bains rail-
road track area, and portions of the PG&E poleyard, and
the Curtaceio, Rogge, and Demeter properties.
5.0 STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions, an innovative technology (silicate fixation
of arsenic soils) and alternative treatment (or resource
recovery) technologies to the maximum extent practicable and
satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a prin-
cipal element.
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Because the remedy will result in hazardous substances
remaining on-site above health-based levels, a five-year review,
pursuant to CERCLA Section 121, 42 U.S.C. Section 9621, will be
conducted at least once every five years after initiation of the
remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
~ .
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John Wis
Deputy Regional Administrator
'3 . V.Q2.
Date
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
CONCURRENCES FOR
POULENC INC/ ZOECON CORP SUPERFUND
RECORD OF DECISION
SITE
RHONE
I concur with the remedy selected for the RHONE POULENC
INC/ZOECON CORP Superfund site and recommend that the Deputy
Regio~al Administrator sign the Record of Decision.
. kson, Director
Waste Management Division
--~~&_-
Date
'J.
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Keith Takata
Assistant Director for Superfund
Hazardous Waste Management Division
-~=-!f=:BL._--
Date
-~~~~~---
Hazardous Waste Management Division
__~6L~~-
Date
~-~-~----_:_-----------
~i;-;~~son, Chief
.South Bay section
Hazardous Waste Management Division
--_3-fz)!!:::_-
Date
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RosQ Marie Caraway
Remedial Project Manager
Hazardous Waste Management Division
__2J~L'j~____-
Date
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Stree1
San Francisco, Ca. 94105-3901
CONCURRENCES FOR
RHONE POULENC INC/ZOECON CORP SUPERFUND SITE
RECORD OF DECISION
I concur with the remedy selected for the RHONE POULENC
INC/ZOECON CORP Superfund site and recommend that the Deputy
Regional Administrator sign the Concurrence Record of Decision.
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Water Management Division
'3.L1-{?-~----
Date
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
J.t
DECISION SUHMARY
Prinrftl on Reqclftl p".
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PAR'r
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
SECTION
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
2.0
2.1
2.2
2.3
2.4
3.0
4.0
5.0
5.1
5.2
5.3
6.0
6.1
6.2
6.3
CONTENTS
PART II:
DECISION SUMMARY
site Name, Location, and Description
site Name and Location
Regional Topography
Climatology
Adjacent Historical Land Use
Hydrogeology
Water Use
Surface and "Subsurface Features
site History and Enforcement Activities
History of Site Ownership
History of contamination
History of Enforcement Actions
History of Site Activities
Community Relations
Scope and Role of the Response Action
Summary of Site Characteristics
Sources of Contamination
Description of Contamination
Conclusion
Summary of Site Risks
Contaminant Identification
Risk Characterization
Presence of Sensitive Human Populations
PAGE
1
1
2
3
3
4
6
7
21
21
21
24
27
29
31
39
39
39
41
49
49
51
52
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PART
II
II
II
II
II
II
II
II
II
:;.
SECTION
6.4
6.5
7.0
7.1
8.0
9.0
9.1
10.0
11.0
CONTENTS
Presence of Sensitive Ecological Systems
Conclusion
Applicable or Relevant and Appropriate
Requirements (ARARs)
Types of ARARs
Description of Alternatives.
comparative Analysis of Alternatives
Ground.Water and Soil
Statutory Determinations
Documentation of significant Changes
"
PAGE
53
55
58
58
82
95
96
107
107
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PART III:
RESPONSIVENESS SUMMARY
III
Responsiveness Summary
109
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I --
LIST OF TABLES
TABLE
TITLE
2.1
Estimate of Materials Formulated
at 1990 Bay Road in 1967 .
4.1
Proposed Cleanup Standards
1990 Bay Road Site, E. Palo Alto
Range of Chemicals found in
Groundwater, Surface Water,
Air, and Soil
. 4.2
4.3
Estimated Vol. of Contaminated Soil
Upland Operable Unit
Groundwater Cleanup Standards for
Deep Aquifer
4.4
6.1
Baseline CUmulative Health Risks
Associated with Exposure to the
Upland Soils
Recommended Final Health-Based Goals
and Associated CUmulative Risks
6.2
~.
7.~
Applicable or Relevant and
Appropriate Requirements Upland
Operable Unit
8.~
Estimated Costs of Alternatives
Upland Operable unit
9.~
Documentation of ARARs for
Alternatives Upland Operable unit
Comparison of Alternatives Upland
Operable Unit
9.2
9.3
Arsentic-Affected Soil:
of Alternatives
Comparison
PAGE
28
34
35
37
38
56
60
93
102
~05
106
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LJ:ST OF FJ:GURES
FJ:GURES
TITLE
1.1
site and Vicinity Location Map
1.2
site Area Designations
1.3
Property Boundaries
1.4
Surface Drainage Patterns
1.5
Survey of Business and Residences
within A 1/4 Mile Radius
1.6
Location Map
Boundary Between Confined and
Unconfined Zone
1.7
1.08
Hydrogeologic Cross Section A-A'
Hydrogeologic Cross Section B-B'
Hydrogeologic Cross Section C-C'
Hydrogeologic Cross section D-D'
Location of Wells
1.09
1.10
1.11
5.1
5.2
Contour Map of June 1990
Water Levels
Upper Shallow Zone
~.3
Average Concentration of Arsenic
in Shallow Aquifer
5.4
Perimeter Monitoring Wells
5.5
Contours of Soil Arsenic
Concentrations
5.6
Vertical Extent of Soil with Arsentic
Concentrations Greater Than 20 mg/kg.
8..1
Proposed Slurry Wall Location
Proposed Remediation Plan Upland
Operable Unit
8.2
PAGE
10
11
12
13
14
15
16
17
18
19
20
42
43
44
45
46
47
93
94
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UNITED STATES ENVIRONMENTAL ~ROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
PART II. DECISION SUMMARY
This Decision Summary provides an overview of the problems
posed by the Rhone Poulencj(Zoecon)Sandoz site (nthe Study
Area"), the remedial alternatives, and the analysis of the
remedial alternatives. This Decision Summary explains the ra-
tionale for the remedy selection and how the selected remedy
satisfies the statutory requirements of CERCLA.
1.0
SITE NAME, LOCATION, AND DESCRIPTION
1.1
SITE NAME AND LOCATION
~
Rhone Poulenc/(Zoecon)Sandoz
1990 Bay Road
San Mateo County
East Palo Alto, CA
Rhone-Poulenc, Inc
P.O'- Box 125
Black Horse Lane
Monmouth Junction,
NJ 08825
Sandoz Crop Protection
Corporate Headquarters
1300 East Touhy Avenue
Des Plaines, III 60018
708-699-1616
Corporation
The Rhone Poulenc/(Zoecon)Sandoz site consists of the
property located at 1990 Bay Road in the City of East Palo Alto
and contiguous lands. Contamination is present on 13.19 acres of
which 5.19 acres is currently owned. by Sandoz Crop Protection
corporation and 8 acres is owned by the adjacent property owners
to the west, south and east. The adjacent properties include
those owned by J. G. Torres, Incorporated (includes former Call-
Mac Property), Pacific Gas and Electric Poleyard, Borrmann Steel
Company, Inc., Ronald G. Rogge, Michael Demeter, Melvin Curtac-
cio, the City of East Palo Alto, and the City of Palo Alto.
Figures 1.1 - 1.3 show site location, site boundaries, and
property boundaries.
The site is located about 2000 feet east of San Francisco
Bay and about 4500 feet northwest of San Francisquito Creek, a
tributary of the Bay. Tidal and non-tidal marshes border the
site on the east and southeast. The non-tidal marshes are
bounded by levees' with a portion constructed before 1939 and
another portion by 1955.
PrintH on RecydH Pa~
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The city of East Palo Alto lies in a relatively flat lying
portion of the Santa Clara Valley approximately 35 miles south of
San Francisco (see Figure 1.1). Ground'surface elevations are
generally between 6 feet and 8 feet above mean sea level. This
, is an industrial setting, dominated by auto wrecking yards and a
large chemical recycling company.
Surface water at the site and vicinity includes seasonally
ponded water along the west side of the levee, San Francisco Bay
water in the tidal marsh, and San Francisco Bay to the east of
the marsh. Water ponds in isolated low-lying areas up to depths
of three feet. At higher water depths isolated ponds merge to
form a fairly continuous body of water between the non-tidal
marsh and the former Call-Mac (Torres) property. Surface water
from the Sandoz Plant area runs off into a lined ditch located
along the eastern boundary of the plant. A gate valve at the
southern end of the ditch controls run-off between the ditch and
the low-lying Call-Mac property. Surface water from the PG&E
poleyard ponds locally in shallow depressions and infiltrates the
area or evaporates. Most of the surface run-off from the substa-
tion is discharged into the non-tidal marsh via a 2-inch diameter
plastic pipe. The closest subsurface storm drainage system for
. the site extends along Bay Road trom Demeter Street to the inter-
section of Pulgas Avenue and Bay Road (about 500 feet to the west
of the site), where it turns south along Pulgas and connects to
storm drains on Weeks and Runnymede Streets. Figure 1.4 shows
site surface drainage patterns. '
A tidal marsh over 1,000 feet wide exists between the levee
and San Francisco Bay. The tidal marsh is drained by a network
of tidal channels, however, the marsh surface within 200 feet of
the 'levee is frequently exposed because the surface elevation is
greater than the mean high tide level.
There are approximately 20,000 people within a two-mile
radius of the site, with the closest residence located about 500
feet southwest of the site, at the northeast corner of Pulgas
Avenue and Weeks Street. None of these residential areas are
within the area impacted by the past chemical releases from the
Rhone Poulenc site. There are approximately seven schools and
playgrounds within the 1.5 miles surrounding the site. The
closest school 1s located .27 miles south of the site. The
Ravenswood Children Center located at 1286 Runnymede Avenue has
185 students. Figure 1.5 shows a survey of businesses and
residences within a quarter mile radius of the site. There are
fishing areas, hiking trails, and a nature preserve located in
the wetlands adjacent to the site.
1.2
REGXONAL TOPOGRAPHY
The Study Area is located near the edge of the Santa Clara
2
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Valley which extends southeast from San Francisco Bay and is
bounded by the Diablo Range to the northeast, and by the Santa
Cruz and. Gabilan Ranges on the southwest (see Figure 1.6).
The Santa Clara Valley is a large structural depression in
the Central Coastal Ranges of California. The Valley is filled
with alluvial and fluvial deposits from the adjacent mountain
ranges. These deposits are up to 1,500 feet in thickness. At
the base of the adjacent mountains, gently sloping alluvial fans
of the basin tributaries laterally merge to form an alluvial
apron extending into the interior of the basin.
1.3
CL:IKATOLOGY
~
The East Palo Alto area has pronounced wet. and dry seasons
with mild wet winters and warm dry summers characteristic of a
Mediterranean climate. The area lies in the path of winter
storms which periodically sweep inland from the North Pacific.
Freezing temperatures and snow are extremely rare. Rainfall from
the winter storms range from moderate to heavy. Precipitation
data is available from the many weather stations in the area.
Records show the average annual rainfall to be about 15 inches.
The site averages approximately-10 to 14 inches of rainfall per-
year. Over 75% of the total annual rainfall in this area occurs
during the winter months of November through March. The average
annual wind speed is approximately 6 to 7 mph (about 3 m/sec)
with slightly stronger winds occurring in the summer. Winds in
the area are predominantly from the west northwest.
1.4
ADJACENT AND HISTORICAL LAND USB
The East Palo General Plan establishes land use within the
city. The site is part. of the Ravenswood Industrial Park, which
is zoned as either light industrial (M-1) or heavy industrial
(M-2). The areal extent encompasses the area south of the site to
a line 110 feet north of Weeks street, north of the Dumbarton
Bridge Road (about one mile), and west of the site to the
Southern Pacific right-of-way (about 1500 feet).
The site also lies within the 186-acre area designated as
the Ravenswood Redevelopment Project by the East Palo Alto
Redevelopment Agency (EPARA). The goal of the agency is to
'evaluate redevelopment concepts for the Ravenswood Project.
EPARA adopted the Ravenswood Redevelopment Plan in 1990 which
states that the area would. maintain its industrial status. The
closest residences are approximately 500 feet southwest of the
site.
Planned land use outside the industrial zone is varied, in-
cluding high-density housing a number of blocks to the south,
3
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recreational use along the dike area, possible development of
Cooley Landing as a marina approximately a quarter of a mile to
the east, continued use of the marsh as a wildlife and bird-
watching habitat, and continued medium-density housing in the
area a quarter of a mile to the west.
1.5
HYDROGEOLOGY
Regional Hydrogeology
The Santa Clara Valley groundwater basin is divided into two
broad areas: 1) the forebay, and 2) the confined area. The
forebay occurs along the elevated edges of the basin where the
basin receives its principal recharge(see Figure 1.7). The con-
fined area is located in the flatter interior portion of the
basin and is stratified or divided into individual beds separated
by significant aquitards. The confined area is divided into the
upper and lower aquifer zones. The division is formed by an ex-
tensive regional aquitard that occurs at depths ranging from
about 100 feet near the confined area's southern boundary to
about 150 to 250 feet in the center of the confined area and
beneath San Francisco Bay. Thickness of this regional aquitard .
varies from about 20 feet to over 100 feet.
Several aquifer systems occur in the upper aquifer zone
separated by aquitards which may be leaky or very tight.
Groundwater contamination at the site is confined to the zone
within the upper aquifer zone. The lower aquifer zone occurs
beneath the practically impermeable regional aquitard. Numerous
individual aquifers occur within this predominantly aquitard zone
and ail groundwater in this zone occurs confined.
site Hydrogeology
A shallow aquifer exists as two zones between 5 and 35 feet
below ground surface and a deep aquifer occurs b~low a depth of
160 feet. The shallow aquifer is underlain by about 100 feet of
low permeability clay which separates it from a deeper aquifer
used further inland for water supply. The shallow aquifer con-
sists of interbedded silts, clayey silts, and sand lenses. A
relatively continuous sand lens occurs at a depth of about 5 to
15 feet below land surface, and a second relatively continuous
sand lens occurs within the depth interval at about 20 to 35
feet. Site documents refer to the depth interval from about 5 to
15 feet as the upper shallow groundwater zone, and the depth in-
terval from about 20 to 35 feet as the lower shallow groundwater
zone. Figures 1.8 - 1.11 show hydrogeologic cross sections for
the site.
The background water quality of the shallow aquifer is poor.
The total dissolved solids concentrations range from 570 mg/l up
to 30,000 mg/l. The deep aquifer is of drinking water quality in
4
-------
areas of East Palo Alto, Menlo Park, and beneath the site. The
total dissolved solids concentrations in these wells range from
420 mg/l to 746 mg/l. The direction of groundwater flow in the
shallow aquifer is generally toward the south and southeast with
some evidence of seasonal fluctuations. The rate of groundwater
flow in the shallow aquifer was estimated to be in the range of
10 to 60 feet per year. The calculated rate of arsenic movement
in the more permeable deposits in the upper 40 feet is no more
than about 4 feet per year. The average rate of arsenic movement
is about one foot per year. .
:I.
From the late 1970's through the summer of 1988, downward
vertical migration of the groundwater plume was not possible be-
cause the vertical groundwater gradient between the shallow
aquifer and the deep aquifer was upward. Since the summer of
1988, as a result of pumping in the deep aquifer in the Palo Alto
area due to drought, the vertical gradient has been downward.
Calculated rates of vertical migration of the groundwater plume
are less than one inch per year. Contaminants in the shallow
aquifer would have to migrate over 110 feet downward through the
silty-clay aquitard to reach a drinking water source.
Estimated hydraulic conductivities in the upper shallow
groundwater zone are in the range to 8.5 ft/day to 28 ft/day, and
are in the range of 20 ft/day to 85.ft/day in the lower shallow
groundwater zone. These values are within the range reported for
silt and silty sand. The estimated average hydraulic conduc-
tivities in the upper and lower shallow groundwater zones at the
site are 23 and 28ft/day, respectively. Horizontal hydraulic
gradients for groundwater moving away from the site range from
0.0004 to 0.001 ft/ft. Assuming an average hydraulic conduc-
tivity of 23 ft/day and an effective porosity of 0.25 for the up-
per shallow groundwater zone, the pore (interstitial) velocity is
estimated to range from 13 to 34 ft/year for groundwater travel-
ing off site. Assuming an average hydraulic conductivity of 28
ft/day, a horizontal hydraulic gradient of 0.001 ft/ft, an effec-
tive porosity of 0.25 for the lower shallow groundwater zone, the
average pore velocity for this area is 40 ft/year. .
The RI report noted that groundwater from the shallow
groundwater zone may be discharging at a slow rate to the non-
tidal marsh, where it evaporates, and/or to the tidal marsh lo-
cated to the east and south of the site. Groundwater discharge
to the tidal marsh is most likely to the tidal channels. A rela-
tively large tidal channel along the west side of the tidal marsh
located southeast of the site may provide an area of discharge
for the shallow groundwater zone.
The site and vicinity is located within the 100-year coastal
flood zone classified by the Federal -Emergency Management Agency
(FEMA) as Zone A. The FEMA flood elevation for the site and
vicinity is 7 feet NGVD. The site is located within the flood
zone for the following reasons:
5
-------
a)
location on low-lying lands adjacent
cisco Bay and San Francisquito Creek
accumulation of surface run-off from
areas during storms
presence of high water table.
to San Fran-
b)
adjacent
c),
. .
1.6
WATER USE
There are a number of beneficial uses of the surface water
and groundwater. Local surface waters include ponded water in
the non-tidal marsh area on the west side of the dike, tidal
waters in the marsh on the east side of the dike, San Fran-
cisquito Creek and the Bay itself. The groundwater at a depth of
150 feet or more is a drinking water source.
Historically, extensive groundwater pumping has occurred
. from the alluvial deposits on the perimeter of San Francisco Bay.
. Groundwater from sand and gravel zones below 160 feet was the
main source of water supply for the cities along the western
shore of San Francisco Bay until the 1960s. To prevent saltwater
intrusion into the aquifers and' to thwart land subsidence pumping
was curtailed in the 1960s.
Water wells completed in aquifers deeper than 150 feet below
land surface are used by three water supply companies in the
area. All of these wells are located upgradient of the site with
respect to the shallow permeable zones and are more than 3000
fee~ west and northwest of the 1990 Bay Road site. The San Mateo
County Public Works Department operates a well at Bay Road and
Gloria Way, which is located approximately 3500 feet west of the
site. In 1988. this well was pumped and used for street sweeping.
The Palo Alto Park Mutual Water company operates five wells lo-
cated approximately 5400 feet west of the site. These five wells
supply about 1300 gallons per minute in summer and half this
amount in the winter. The O'Connor cooperative Tract operates
two wells approximately 7500 feet southwest of the site and they
pump a total maximum of about 525 gallons per minute. A well on
the east end of Bay Road is used exclusively by a boat repair
facility, and the Iwasaki well is used by Saturo Iwasaki
Greenhouses for agricultural purposes. The spring Valley Water
Company constructed the Ravenswood wells as water supply wells in
the tidal marsh east of the site in the early 1900s. These wells
were artesian until 1928. The wells were abandoned improperly
and saltwater entered many of the wells at high tide. The wells
were eventually filled and sealed.
The area which includes the 1990 Bay Road site and vicinity
is served by the East Palo Alto County Waterworks Company, which
receives most of its supply from the Hetch Hetchy surface water
supply system. The Hetch Hetchy Aqueduct carries surface water
6
-------
from the Sierra Nevada Mountains about 120 miles to the east.
There is no apparent mechanism by which domestic water supply
systems could be impacted by site contaminants. Approximately,
56,000 people' are served by the Palo Alto water supply system,
and 4,300 residents of East Palo Alto receive 2000 acre feet of
their water from the Hetch Hetchy Reservoir. Groundwater cur-
rently accounts for zero percent of the municipal water supply.
However, there is one domestic well installed and when the water
suppliers start pumping from this well groundwater could account
for up to 10% of the water being delivered to East Palo Alto.
The existing and potential beneficial uses of the surface
waters (San Francisco Bay and San Francisquito Creek) and marshes
include:
b.
d.
e.
f.
g.
h.
j .
k.
a.
contact and non-contact water recreation
warm and cold fresh water habitat
fish migration and spawning
commercial and sport fishing
rare and endangered species preservation
estuarine habitat
wildlife habitat
salt marsh habitat
navigation
shellfish harvesting
industrial service supply
c.
i.
Existing and potential beneficial uses of currently
taminated groundwater in the vicinity of the site within
shallow and deep aquifers could be adversely affected if
spread of contamination remains uncontrolled.
,~
uncon-
the
the
. ~he existing and potential beneficial uses of
groundwater underlying the site include industrial
supply, industrial service water supply, municipal
water supply, and agricultural water supply.
1.7
the
process water
and domestic
SURFACE AND SUBSURFACE FEATURES
The non-tidal marsh is owned by Pacific Gas and Electric
(PG&E) and consists of a triangular area separated from the tidal
marsh(located to the east) by a levee that rises approximately
four feet above the area. The area is primarily covered by wet-
land vegetation, .with some barren areas, and is submerged during
the rainy season. The surface elevation in this area varies from
5 to 7 feet along its western boundaries to approximately 3 feet
along the levee.
The PG&E poleyard, consists of a fenced rectangular, 3/4
acre plot of unvegetated land that is essentially level at an
average elevation of 6.5 feet. Shallow ponding occurs during the
rainy season.
7
-------
The area north of Bay Road, is partially owned by the City
of East Palo Alto, Ronald G. Rogge, and Michael Demeter. The
predominant business in this area is auto wrecking yards. This
area is mostly level, and the street is paved.
The northern portion of the Sandoz property, occupies ap-
proximately 2 acres and is generally level at an average eleva-
tion of 7 feet above mean sea level. . It is undeveloped and was
partially covered by low, grassy vegetation, with some barren
areas. This portion of the site was the location for the former
sludge pond. The entire perimeter is enclosed by chain-link or
wooden fences. During the rainy season, surface water tends to
pond locally to depths of a few inches.
The sludge pond was in existence between the 1950s and
Rhone-Poulenc's plant closure in 1971, as confirmed by aerial
photographs taken between 1955 and 1969. The pond was reportedly
a rectangular unlined impoundment surrounded by a three-foot high
berm. Liquid wastes, rinsate from Tank L, and damaged containers
and products are suspected to have been disposed in the sludge
pond. The pond was filled.with lime, excavated soil, and berm
materials when the pond was closed in 1971.
The 3.19 acre Sandoz plant at 1900 Bay Road is developed and
the following buildings are on. site: office, process, packaging,
maintenance/shop, other miscellaneous buildings, and two tank
farm areas (Figure 2.2). On a RWQCB underground tank question~
naire submitted by Zoecon in February 1983, the company listed
five underground tanks and sumps for the storage of hazardous
wastes. The tanks are reportedly used to store aqueous solvent
wastes and to contain solvent spills. Hexane, methanol, toluene
and n-methyl pyrrolidine are received in bulk and stored in tanks
with. volumes that range from 5500 - 6000 gallons. Chemicals
delivered in metal or plastic drums are stored in an open druE
lot which is covered with asphalt and has an accompanying slopage
to promote drainage. A railroad spur was located along the
southern edge of the plant area at an average elevation of 7
feet. The railroad spur was removed during August 1991.
The former railroad spur extended west and the land is now
owned by William and patricia Bains. This area has been filled
to a level grade of approximately 7 feet with gravel.
The area to the south of the site is owned by J.G. Torres
Construction Comp~ny. This southern area is undeveloped, covers
approximately 8 acres, and the northern portion of this area is
the location of the former Call-Mac site. Elevations in the
northwestern portions of the area range from 3 to 8 feet. Prior
to September 1991 the area was covered by high, grassy vegeta-
tion. During the rainy season, the eastern portion of the Call-
Mac property is submerged. The sQutheastern corner is hummocky,
with elevations varying from 3.5 to 10 feet. The low.areas be-
tween the. hummocks are also submerged during the rainy season.
8
-------
The CUrtaccio property lies immediately. to the west of the
site and is covered by a concrete slab. The average elevation of
this area is 6.5 feet.
The tidal marsh is intermittently submerged throughout the
year due to tidal influences. The wetland vegetation and network
of tidal channels is part of the Laumeister Tract which is owned
by the City of Palo Alto.
9
-------
, Reference:
Palo Alto (1960 and Hayward (1959) Quadrangles,
California, 15 minute Series (Topographic). United
States Depanment of the Interior, Geological Survey.
o
"
3000
I
, 6000
I
lz~6
I
Ft.:
OEOMATRIX
SITE AND VICINITY LOCATION MAP
1990 Bay Road Site and Vicinity
East ,P,alo Alto. California
Figure
1.1
, -.
~
Projoct No.
1220A-1500
10
-------
~
:,t
C.=J.
()
I I
. .
I
I
r1
. -
. Former
underground
tank
- Levee
eXPu'NA TION
Approximate site boundary
Weiland operable unit
o
I
200 Feet
I
tnuwm
-
Upland operablo unit
~
o 80MATR \)(
SITE AREA DESIGNATIONS
1990 Bay Road Site
East Palo Alto. California
Fogu.e
1.2
Proj~t No
1220F
11
-------
Melvin A.
Curtaccio
-S Ronald G.
4! Rogge
~
(,)
Ii
.s
~
~
City of
Palo Alto
J. G. Torres
~.
a I!OMATRIX
PROPERTY BOUNDARIES
1990 Bay Road Site
East Palo Alto. "California
o 200 Feet
I I
Figure
1.3 .'
Project No. -
1220F
12
-------
t::>
I
.1.3
lI'lUU'OI
,-
""",,'10 ..."., lfo." IGYO)
01,..11.. .t ...fo.. ...1..,.
-
c::::: o.lIl...t ,.,.,..,'Ie t..h..
-
E8
II" ... ,lelol., .... ,......,
'''01 .,....1 ,..,110' 1...,10.
"-11 m
,.... .,11
IOIU
I. ,... .., ,... ...,.... ...,1" ".. hi"..,
,... .., ., 111010, .... ... YIeI.II"
..... .. ..,hi ,..1.,..,., ,.t.. ..
0......, II. '"I ... .,,11 II, "", ...
"8,-18,. ,..,ra... ., "11"., s..lIh." C
e.,p..,.
I. ,..J... ........" ".... ,.... .. 50001,
1000( .. 10",...11.. ., 10, .... ...
"I,.. h...,.
1
o
I
200 Feet
I
SURfACE OAAlftAGE PATTERNS
1990 .IY ROld SIte Ind VIcInIty
Elst '110 Alto, C.II(onl.
~
a80MATJIIX
"'1'01 HI.
1220A-1500
'Ig...
1.4
-------
~
UIxM - ft8IQIIbOrftOCI8
. . .
KEY
R = Pri vate resi dences "
y-
101
Mud... ~a I d.
",
~A-
".M UN ILl n .
nelghboltlooda --- -
Notes
1. Map of 1990 Bay Road and vicinity
based on aerial photographs from
Pacific Aerial Photos made on
December 11, 1985
2. See Table 12 for number of employees
present at the facilities shown
based on interviews conducted in
October and November 1988.
o
I
400 Feet
I
0S2S=
SURVEY OF BUSINESSES AND
RESIDENCES WITHIN A 1/4 MILE RADIUS
OF THE 1990 BAY ROAD SITE
East Palo Alto, California
Figure
GEOMATRIX
1.5
Projoct No.
1220A-1500
. -,
."
" 14
-------
. .. .~.. "'"
, ""'"'''.''-''''''' -. ....
".t:llic
Oc.... 0
. ..h'.~ ~'... .......-.. "'_.~w "."
. .,. ..'. --......... -...---..-... ....
.J. "''''''''''.._n.-
f,
C . - ~ -
. ... r.. C: r .-'- .. C'. .'"
" "'4......".
01 .. - '. ".....~ ~... 61
'1 -. ,..~_.
~~ .J'".. -;, (.,.~" "0
. "0 ~ -,:'. ::-
~ ~ Ii .:
'of -:. l.) c
11-~ ,..&
'(!' n".
..lJ
...
1
-If-
,
H8yw.d
A'~ Cred
-
.
""
BAY
FRANCISCO
-.
SAN
~
b-~~)-:;..("
\
--
- .0
- "
--
New.1t
,
"0
1190 8A Y ROAD SITE
'.10 Alto
"0.. Blylandl.
. ... .'..."- . . "
'.10 AltO
Mountain View
Figure 1-6
lOCATION MAP
15
o
1 Mile
.
-------
"~
~
.
;;
4-11'"11
'. Bd,k
~
..,"
I
.
I
.
I
.." t S
. «
I 1
."OUIIE"S
.
1-- .
'1,...,1ett
IOhbmI taOClHE lAY MUDI"
CaI O!JAmwrf M&.UV1UM"1
I Bdrk J 1tfnWfl.t'AE.ftR1Wn'IIEOROCIC'"
/ FAtA.T '" C,.. 01'* n.. S.dndre.und"""""
and.. ScUh8tft EdIMIOII.' 0..'" J
. /". IOJIIWIY IE1MtNCOtFMDZQfUHDUNCOHfMD ZOHI.UI
/:\: CQtI'MD ZQtC IfHCAnt CEHTCR O1BASIH. UNc;OHf"EO ZONE
0CQIft$ ~OHO BASIH fMRQIH
Bdrk
Figure 1-7
16" .
-------
South
A
I
Aria J
Ar.. 4
.,
Aria 1
North
A'
I
o
~
r-S8cUon 1.1'
Z h ;~ ,i
.~.
,h)' 110,11
10
-r-
Upper 5hlll0'0l
Ground.iter
lone
--'-- -10
-10 -
~
T
~
-20 -
g
':;
..
.
..
...
lo,",er ,5hlllow
Groundw,ter -30
lone
~
. )0
-40
-50
-50
EX'lAIIATiOH
80&&08 0'
borllll
lIotl'
1. 'hi geologic unltl connectld bit_II IIDrlllll hlYI b..11
In'lrr.d and .r. lIa..d OIl Int.rpolaCion blt"..n wld.l)'
Ip"l. polntl and, In part, on work per'ol'8td 111 othera.
Thl contactl between thesl units are .hown 41 .0114
Itn.. 'or cllrltl and arl not .,IIt tll 181'1)' c:ertatnt)'.
.".r to Ilthololllc lOll' 'Dr "IL'"I of subsurfaci
condltlonl.
Z. Sletion 1111. Ihovn on FIgurl J.
J. A eOllpllt. "Itlng 0' 1011 Irslllic COn.llltratlonl II
pr..lnted In A IIdle.. 0 all4l t. JIIII)' Slleetl" ¥II,,,
Irt IhOllll on Igur..
o
I
/IorhonUI lcall
100 'eet
~ Concrlt., asph,lt, UII
~ ClIl. s1ltl clal. IIndl dll
I\*#t;;\ Sindy stlt. eIIY'Y und
o Stlt)' SInd
~ Sind, traY.I, ..ndlgrIY.I,
grnll 'I Und
COli tour of .rs.nlc conc.nLntlons,
,dashed wh.r. In'.rr.d
SoI1 ar,,"Ic
10 c:OIIC'"tr,tlOII'
III III/kg
Sand pack
Intlrval
Perforatld
Int.r" )
HYOROCfOlOGIC CROSS SECTION A-A'
1990 81Y ROld Sit. and Ylclnlty
hst Palo Alto. Callfornll
;?S2S:=
a8QMAT,.nc
'80""
1.08
P"o... 17
-------
Concretl, .sph.lt, fIll
Clly, sUty chy, sandy clly
S.ndy sIlt. cl.yey s.nd
Silty Sind
S.nd, gr.vel. s.ndy gr.vel,
\lr.ve l1y Sind
--- Contour of arsenIc concentraUons.
d.shed where inferred
T
Upper Sh.llow
Groundw.ter
lone
~-IO
T
-20
Lower Sh. \I ow
Groundw.ter
lone
~
-30
~
Wl2l
1f,~1\1
r::';'1T1, .
~
~
\lest
B
Arel 7
H.
Area Z
"r-.- Area 8 -I
Tld.1 ..rsh
ElSt
6' .
,I,
Area "
10
rsectlon C-C'
ob
-
,
~
t
,SectIon A-A'
I Section 0-0'
o
-40
EXPLAHATlOn
o 100 reet
I J
HorIzontal scale
SoIl .rsenic
10 concentr.tions
In 8gfkg
Sand pack
Inten.1
Perfor.ted
interVl1
Hates
I. The goo logIc unIts connected between borIngs h.ve been
Inferred .nd .r. b.sed on Interpol.tlon between wIdely
sp.ced pofnts Ind, fn p.rt, on work p.rfonaed by others.
The cont.ctl between these unftl .re ShOWd .1 lolld
11nes (or clarity .nd ,re not ~.nt to laply cert.lnty.
Refer to lIthologIc logs for det.lls of subsurface
conditions.
Z. SecUon lIn, shown on nyure 3. .
3. A complete 1tstlng of so I arsente cpneentr.ttons ts
prlsented fn Applndftes 0 Ind E. Only slll~tld v.lues
are shown on th II fI'liure. ,
~
a80MATRlIC
--~_.
HYDROGEOLOGIC CROSS SECTiOn 8-8'
1\1\10 8.y Road SIte .nd VICInIty
E.st P.lo Alto. C.llfornl.
eott08 of
boring
10
o
Q
>
-10 ~
t
...
c
o
-20 ~
..
"
....
.30
-40
'OJU"
-_._~
-- --~-
-------
Road
Upper Shallow
Groundwater Zone
Lower Shallow
Groundwater Zone
Concrete, asphalt, ftII
City, sllty ctty, sandy city
Sandy silt, clayey sand
Sllty sand
Sand, graveI,.sandy grave),
gravelly land
Contour of arsenic concentrations,
dashed where Inferred
I Soil arsenic
l-10 concentrations
I In «g/kg
B Sand pack
H Interval
|h
i
I Perforated
Interval
Botton of
baring
The geologic units connected between borings have been
Inferred and are based on Interpolation between widely
spaced points and, In part, on work performed by others.
The contacts between these units are shown as solid
lines for clarity and arc not Meant to Imply certainty.
Reftr to litholojle logs for details of subsurface
conditions.
Section line shown on Figure 3.
A conplete listing of soil arsenic concentrations is
presented In Appendices 0 and E. Only selected values
are shown on this figure. '
Horltontal scaje
HtOROGEOlOGIC CROSS StCIIOn c-C'
1)90 8
-------
. ..',
.: .
,0
Upper Shallow -5
Croundwater
Zone
~-15
I
lower Shal10w
Groundwater -25
Zone
J
WZJJ
-
1!~rl~!1
~
Clly, sHty clay, sandy clay
Sandy silt. clayey ,and
511 ty sand
Sand. gravel. sandy gravel.
gran11y Sind'
CDntour Df arsentc concentrations.
dashed wher.,fnferred
I
South
0'
Area 8
Tidal .arsh
I
Harth
O' HORTH
5
Section B-8'~
~
i
5
-35
o
.;
t
-15 ~
a:
2
...
c
~
~
....
-25
-35
o 100 Feet
I I
Hortzontal scale
EXPlAHATiOH
" Hot..
1. The geologic units connected between borings have been
inferred and ar. based on interpolat10n between wfd.ly
spaced points and. in part, on work perfor8ed by others.
The contacts b.tween these un1t. are shOltn as sol1d
11ne. for clarity and are not ..ant to f8ply certatnty.
Refer to IftholQtfc logs for detafls of subsurface
condttions.
2. Settton Ifni shown on figure 3.
3. A complete listing of Soil arsenIc concentratIons Is
presented In Appendices 0 end [. Onl1 selected velull
are shown on this fIgure.
Sot 1 arsenic
10 concentr~tion'
in II!I/kg
Sand pack
interval
Perfor't,d
interval
BottOll of
boring
i
,
~
HYDROGEOLOGIC CROSS SECTION D-D'
1"0 OIY Road SIte Ind Vlclnt~y
tast Palo Alto, California
~
aeOMATRIM
fIOUI'
1.11
-------
2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1
HISTORY OF SITE OWNERSHIP
:J
Prior 10 1926 The site was oa:upied by RcccI Zinc Company.
1926 CUpman OIemicaJ Engineering Company began using the sile for production of
herbicides.
January 12, 1932 O1ipmao OIemical Engineering Company chanp its name to CUpmaa O1emical
Company.
1926 until 1967 The site was operated by the O1ipmao O1cmic:al Company.
December 6, 1967 Rhodia, Inc. merged with CUpman aad bccamc Rhodia, 1m:.. CUpman DiYision.
1m Rhodia Inc., Clipman Division, dosed its East Palo Alto planL"
June 7, 1972 Rhodia. Inc., slICCeISOr by merger to CaipmaD Cacmic:al Company, 50Id the site to
Zoccon Corporation. Zoccon was incorporated in DclawaR in 1968.
Augvst 1977 Occidcntial Pctzoleum Corporatioa aqui=S Zoca3a Corporation. The 1978 edition of
Moody's RpOned that Zoccon would opcntc as a subsidiaty of Hooter Cacmica1
Corporation.
October 20, 1978 Rhodia, Inc: changed its corporate name to Rhoa~Icnc, Inc. The 1984 edition of
Moody's Industrial Manual lists' RhoDe Poulcnc:. Inc.. as the Uniled States
subsidiary of Rhonc-Poulcac SA established in Prmcc in 1895. Rhonc-Poulcac SA ,
maintains a worldwide network of sales offlClCS and production subsidiaries
for agroc:hcmic:als, communication products, textiles. basic and speciality chemicals, and
pharmaceuticals.
1981 Zoccon described its businClili at the 1990 Bay Roa4 addras as tbe maaufacturc of
biorational insect control agents. Products manufactuRd induded mcthopRnC,
kinopRnc, IricoscnC, and adhCIiMs for c:ocIaoach trapL
April 5, 1983 Sandoz United States Inc. pun:hascd Zoca3a Corporatioa from Oc:cidcDtiaL Sandoz
United States, IDe. is an American subsidiaty of Sandoz, Ltd., which was .
incorporated in Switcrtan4 in 189S.
June 1, 1986 Zoccon merged with VcIsic:oI Corporatioa to fODD Sandoz ClOp Protection Company.
-
2.2 HZSTORY OF CONTAMINATZON
Chipman was responsible for the formulation of agricultural
pesticides, railroad right-of-way herbicides, insecticides, and
arsenic-based products between 1926 and 1964. Herbicide manufac-
turing conducted on the site by Chipman and Rhodia involved the
use of arsenic and other heavy metals. Chipman Company cor-
respondence and product labels, show that Chipman was handling
arsenic at the site as early as 1929.
21
-------
In 1929, Chipman was sued by the owner of the adjoining
property concerning contamination of his land with arsenic. The
farmer specifically alleged that Chipman's carelessness had
caused arsenious substances to be deposited onto his land, con-
taminating his alfalfa, and causing his cattle to sicken.
In response to this suit, Chipman began to lease a one acre
parcel of land from the farmer in order to keep cattle from graz-
ing in an area contaminated with arsenic. In a 1938 interoffice
letter from W. H. Moyer to R. N. .Chipman, which discussed the
lease, the author discussed the possibility of buying the one
acre parcel from the farmer. He mentioned the farmer's claim
that arsenic had blown onto the land, and stated that "if there
was ever residential or industrial development on the property,
that there could be considerable difficulty due to Chipman's han-
dling of arsenic in bulk".
Zoecon obtained labels from various Chipman products which
contained registration dates from 1968 to 1972. These labels
show that Rhodia, Inc., Chipman Division manufactured the follow-
ing herbicidal products during those years:
Product
Arsenic Ingredient
Atlas nAil
Atlas nAn 6
Chipman Calcium Arsenate
Chip-cal Granular
Chipman Hi-Test Lead Arsenate
Chipman Hi-Test Lead Arsenate
. 44.0
57.4
70.0
48.0
98.0
90.5
% sodium arsenite
% sodium arsenite
% tricalcium arsenite
% tricalcium arsenate
% lead arsenate
% lead arsenate
A former Chipman employee testified in a 1982 deposition
that these products were stored, repackaged, and distributed at
the East Palo Alto facility from 1959 until 1971. This same
employee testified that Chipman manufactured herbicides at the
East Palo Alto plant, and also received products from a Chipman
plant in Portland, Oregon, and repackaged these products from 50
or 30 gallon drums, to 5 gallon or smaller containers. The
employee also reported that if liquid materials or herbicides
were spilled on the plant floor during manufacturing or breakdown
operations, the chemicals would be washed out the door of the
building and onto the plant grounds. The material reportedly
flowed into a ditch that cut across the property and then flowed
onto the adjoining property. The employee further stated that
dry material spilled on the plant floor would be swept into
drums. These drums would be loaded onto a truck, and the waste
in the drums would be dispersed over the property. Herbicide
drums which were damaged would be dumped into a man made pond on
the property. Incorrectly mixed batches of herbicide also would
be dumped into this pond.
Arsenic raw material was delivered to the facility by rail
or by truck. Southern Pacific shipped arsenic in hopper cars to
Chipman's East palo. Alto plant. The hopper cars would be un-
22
-------
loaded directly into a 50,000 gallon underqround tank located be-
side the railroad track. Arsenic that spilled during this trans-
fer would be washed down into the rocky bed of the track.
Chipman formulated an herbicide product in this underground
tank, for Southern Pacific Railroad as an herbicide to kill
vegetation along its railroad right-of-ways. A study prepared
for Rhone-Poulenc by Woodward-Clyde Consultants determined that
this herbicide was a sodium arsenite compound formulated by
mixing arsenic trioxide with sodium hydroxide in the underground
tank. This herbicide would be pumped from the unQerqround tank
into railroad spray cars. Herbicide material spilled during this
transfer also would be washed into the rocky fill of the track.
Table 2.1 shows an estimate of materials formulated at the site
during 1967.
In 1980, as part of a corporate and company-wide pOlicy,
Zoecon conducted a preliminary environmental assessment of the
Bay Road facility. Soil and groundwater samples revealed that
the site was heavily contaminated with arsenic. .
CALL-DC PROPERTY
~
The Call-Mac site is currently owned by J. G. Torres and is
located within the boundarie~ of the Rhone Poulenc site. This
area was used by Call Mac Transportation for storing of drummed
hazardous wastes for twenty to thirty years. In January 1981,
approximately 1,300 drums was counted on site. According to the
labels, the drums contained allyl alcohol, phosphorus
trichloride, isopentane kerosene, benzoyl chloride, acrolein,
diethylene triamine, triethylene tetramine, and tetraethylene
pentamine.
The material on the easterly portion of the Call-Mac site
was determined to have originated from the Shell Development Com-
pany research laboratories in Emeryville, california in the late
1950's and early 1960s. The material on the west~rly portion of
the site was determined to have originated from the Diamond Sham-
rock Corporation plant in Redwood City, California in the la~e
1960s and early 1970s.
The drums and approximately 25 cubic yards of soils was
removed from the site by Chemical Waste Management, Inc of Ket-
tleman City, California. and International Technologies Corpora-
tion of Benicia, California between March 10 and July 29th of
1981. Confirmation samples taken on September 16th 1981 deter-
mined the following:
(1)
the major contaminant on the property was arsenic soils
that resul te~ from Chipman.' s acti vi ties;
23
-------
(2)
the only soil contamination remaining from the Call-Mac
operations was an area contaminated with triethylene
tetramine that leaked from drums of waste obtained from
the Diamond Shamrock Corporation;
the organic amine contamination was much less
widespread .and less significant than the arsenic con-
tamination.
(3)
EPA conducted a preliminary assessment review of the Call-
Mac property during September of 1989. The preliminary assess-
ment determined that the site was not eligible for inclusion on
the National Priorities List.
2.3
HISTORY OP ENFORCEMENT ACTIONS
This site was proposed for inclusion on the National
Priorities List on October 15, 1984 (49 FR 40320) and then became
subject to regulation under the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) of 1980, as
amended by the Superfund Amendments and Reauthorization Act
(SARA) of 1986. The California Department of Health Services
(DOHS) was the lead agency in regulation of CERCLA/SARA pursuant
to a DOHS Consent Order dated August 27, 1987, and signed by .
Rhone Poulenc, DOHS and the Board.
On June 10, 1986, EPA announced a policy to. list RCRA Sub-
title C facilities on the NPL only if they meet the final RCRA
listing criteria (51 FR 21054). These criteria are: 1)
bankruptcy; 2) loss of authorization to operate/probable unwill-
ingness to carry out corrective action; and 3) case-be-case
determinations of unwillingness. As a result of the criteria
listed above EPA decided to drop sites proposed for the NPL that
did not meet the above criteria. It is important to note that
the only authority available at a RCRA drop site is the use of
CERCLA Trust Fund monies for remedial actions. In October, 1989,
the site was removed from consideration for the NPL by EPA. San-
doz crop Protection Corporation is a RCRA facility which treats
and stores hazardous wastes under Department of Health Services
(DOHS) Permit CAT00061135.
Onder the EPA's RCRA deferral policy, regulation of the site
cleanup continued under DOHS lead pursuant to their 1987 Consent
Order and followed CERCLA guidance, until lead agency status was
changed in 1991. The parties vacated all provisions of the Con-
sent Order by stipulation in February 1991, except for. those
referencing the state's ability to seek cost recovery. Pursuant
to the South Bay Multi-Site Cooperative Agreement (MSCA) and the
South Bay Ground Water Contamination Enforcement Agreement, en-
tered into on May 2, 1985 (as subsequently amended) by the
Regional Water Quality Contro~ Board ("the Board" or "RWQCB"),
EPA and the California Department of Health Services (DHS), the
24
-------
Board has been acting as the lead agency for the site since
January, 1991. The site is currently being regulated under RWQCB
orders.
. Responsible party Determination
The RWQCB has named Rhone Poulenc and Sandoz Crop Protection
corporation as dischargers under California Health and Safety
Code Sections 25356.1 (c) and (d). EPA completed a PRP Search on
June 27, 1985. This search identified Rhone-Poulenc, Inc as a
potentially responsible party for the contamination at the 1990
Bay Road facility due to its previous ownership of the property,
and the arsenic handling and disposal practices conducted by its
predecessor companies. The current owner and operator of the
site, Sandoz Crop Protection corporation has also been identified
as a potentially responsible party due to its ownership of the
property.
Agreements Among Responsible parties
In January 1982, Zoecon filed a lawsuit in San Mateo Supe-
rior court against Rhone-Poulenc, its predecessors, and Southern
Pacific Transportation Company. In February 1986, Rhone Poulenc
and Zoecon entered into an Agreement of Release and Indemnifica-
tion agreement. Rhone Poulenc has been overseeing all site
cleanup activities.
:J.
Enforcement History
A draft Remedial Action Plan dated July 31, 1986 was
review~q by EPA and in a September 1, 1986 letter EPA stated that
"the RAP, which was prepared by Rhone-Poulenc, does not meet the
intent of the National Contingency Plan and CERCLA guidance for
Remedial Investigations and Feasibility Studies (RI/FS)". EPA
cited four major concerns with the July 1986 Remedial Action
Plan. One concern was that the remaining levels of arsenic
proposed to be left on site and the vicinity would exceed the
designated RCRA hazardous waste level and that the contamination
at the site had not been adequately characterized by the Remedial
Investigation. Three major concerns with the Feasibility Study
were also cited. They included completion of an exposure assess-
. ment pursuant to CERCLA guidance, evaluating a full range of
cleanup alternatives, and the evaluation of each alternative was
not adequate. Based on this information the remedial investiga-
tion was reopened. In August 1989 Rhone Poulenc submitted a
. second. Feasibility Study. Review of this document by EPA and
u.S. Fish and Wildlife Service determined that the Remedial In-
vestiqation for the site had not completely addressed wetland
issues. EPA and u.S. Fish & wildlife "Service made the determina-
tion that Rhone poulenc needed to perform a ecological assessment
for the site before the agencies could determine whether or not
25
-------
the wetlands at the site had been impacted by site activities and
subsequently evaluate remedial alternatives for cleanup of the
wetlands.
After the agency lead for the site was switched from
,California Department of Health Services to the California
Regional Water Quality Control Board, the site was also divided
into two operable units (Wetland OU and Upland OU). A workp1an
for the ecological assessment was submitted on May 14, 1990.
The following is a chronology of important Rhone Pou1enc
regulatory activities.
1.
Regional Board adopted Cleanup and Abatement Order No.
82-001 on April 15, 1982, requiring the dischargers to
determine the lateral and vertical extent of heavy met-
als and organic compounds in the soil and groundwater
both on and off-site. Subsequent revisions of the Or-
der were made to allow additional time for completion
of tasks; Order 82-002 adopted on April 21, 1982, Order
82-005 adopted on October 13, 1982, and Order 83-012
adopted on December 20, 1983.
Regional Board Order 85-67 was adopted on May 15, 1985.
The Order required installation of a monitoring well
network in the shallow and deep aquifers and submit
results of groundwater sample analyses.
2.
3.
Regional Order 87-052 issued 5/20/87. Order setting
Amended Administrative Civil Liability Order No. 87-
001. Issued due to failure of Rhone Pou1enc to install
monitoring wells and submit sample results according to
the schedule in Board Order No. 85-67. Administrative
civil liability payment in the amount of $25,000 was
paid.
Department of Health Services Consent Order dated
August 27, 1.987, and signed by Rhone Poulenc, DOHS and
the Board.
4.
5.
RWQCB Site Cleanup Requirements Order No. 91-01.6,
adopted February 20, 1.991. (rescinding and replacing ex-
isting order to reflect change in lead agency, to in-
clude tasks necessary to complete the FS/RAP process,
to update groundwater monitoring and to ensure design
of an adequate groundwater mitigation response for
final site cleanup).
6.
RWQCB site Cleanup Requirements
adopted June 19, 1.991. (amending
add provisions for implementing
Plan (EARP).
Order No. 91-095
Order No. 91-01.6) to
an Early Action Removal
26
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1-
2.3
BXSTORY OF SXTB ACTrv%TIBS
Interim Remedial Actions
In ~981, under direction of DTSC (then DOHS), drummed waste
and associated contaminated soil unrelated to Rhone Poulenc/
(Zoecon) Sandoz (RP/ZS) were removed by Shell Development Company
and Diamond Shamrock from the northern portion of the Torres
property (see Figure 2, Call-Mac Property). Interim actions at
the site have included monitoring of groundwater in the shallow
and deep groundwater zones with a monitoring well network in-
stalled under Board Order 85-67. In March ~987, pursuant to an
order issued by DTSC, RP/ZS installed a fence around certain
areas of the site corresponding to the approximate 50 mg/kg soil
arsenic concentration and posted warning signs.
:i
On April 30, ~991 RP/ZS submitted an Early Action Removal
Plan presenting technical documentation and construction
methodology for conducting excavation of soils with high con-
centrations of arsenic. Extensive soil sampling was conducted
during June and July 1991. On August 15th, RP/ZS submitted a
Pre-excavation Sampling Report and a more detailed Construction
Plan for the 1991 removal. During August 199~ RP/ZS completed.
several pre-excavation activities which consisted of the follow- .
ing:
L
Removal and disposal of wooden railroad ties in the
former track area as a hazardous waste;
2.
Removal of approximately 2000 lineal feet of buried
. pipelines, four steel boxes, and one concrete and steel
hopper located in the former railroad track area;
Removal and rerouting of a 120 foot long section of
3-inch diameter steel water-supply pipe located above
ground to the Sandoz plant .
The Early Action Removal completed in September, 1991 in-
volved the removal of s~ils containing concentrations of arsenic
greater than 5000 mg/kq from the undeveloped portion of the San-
doz property and the northern po~ion of the Torres property.
Approximately 5900 tons (4000 yd , 268 truck loads) of soil was
excavated and disposed of offsite at a Class I facility in accor-
dance with state and federal land disposal regulations. This was
accomplished in accordance with the Early Action Removal Plan ap-
proved by Regional Board Order Amendment 91-095.
3.
27
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.,', :.f.
. '
"". .....
Tid:ile 2'; 1
, '-
ESTIHATE or HATE~I~lS FORMULATED AT 1990 BAY ROAD IN 1967
1990 BaY,Road Site .
Powder Ranking location
Actfve or 2 by' of ~3 ~:~~:f~~~s
Haterial In9redientsl .IJ..uiIl ~2 ~2 Formu1aUon3
Ch10rax 40 & sodium chlorate (40%) Powder 2 422;280 lb Bdg H "arehouse 0 50-1b bags
Sh.d~A-Leaf sodium metaborate (60%)
"
Chlorax 285 sodtum chlorate Powder 4 34.800 lb DdgH "arehouse 0 50-lb bags
sodium metaborate
Chlorea 3 sodium chlorate Powder 5 3,400 lb Bdg ~ "arehouse 0 50-lb bags
sodium metaborate
manu ran '
Chlorta 125 sodium chlorat. Powder 3 154,050 lb Bdg. H "arehouse 0 50-lb bags
sodtum metaborate
manuron
Sodium sodium metaborate Powder 1,209,600 lb Ddg H Wa r-ehouse 0 Shipped In bulle
Hetabor-ate to other plants
Atlas A sodium arsenite Liquid 3 21.839 gal Tank L Tank F 30-gal drums
Atlas A-6 sodium 'arsenite Liquid 4 19,300 gal Tank L Tank F not /cnOIom
Atlas "P&C ~t.r- and sodium Liquid 5 530 ga1 Tank J not known 5-9a1 buckets
chlor-ide (Inert)
8roml ci1-5 Br-omi ct 1 and Liquid 2 138,168 9al not known not known not known
(Brotab) 2.3.6-Tr-Ichlobenzoic
acid «1%)
~. 5hed-A-Leaf sodium chlorate liquid 139,000 gal Tank L Tank E 30-ga1 drums or
4000-ga1 tank trucks
Chlorax liq. sodlulII chlorate Liqu'd 150,000 gal/tra'n4 Tank L Tank E not known
S.r.2
2
3
~ctfve Ingr-.d'ents as listed on conta'n.r lab.ls 'n "I.s.
For- January I, 1967 to October 31, 1967 as reported by t.E. "ollllck.
See Flgur. 16 (or- building and ta~k locations.
Estfllllted: more than 1 train per year.
4
"
0773B/052481
'.
.
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3.0
COMHm1:ITY RELATIONS
:j
An aggressive Community Relations program has been ongoing
for all Santa Clara Valley Superfund sites, including the Rhone
Poulenc/Sandoz site, and the requirements for public participa-
tion under CERCLA Section 113(k) (2) (B) (i-v) have been met. The
RIfFS and Proposed Plan for the Rhone PoulencfSandoz site was
released to the public on November 1, 1991. These two documents
were made available to the public in both the administrative
record and an information repository maintained at the RWQCB of-
.f ices in Oakland, CA and the East Palo Alto Public Library. The
RWQCB published a notice in the Peninsula Times Tribune on Wed-
nesday, October 31, 1991 and Wednesday, November 6, 1991, an-
nouncing the RIfFS, Proposed Plan and opportunity for public com-
ment at the Board Hearing of November 20, 1991 in Oakland, and
announcing the opportunity for public comment at an evening
public meeting at Tulip Jones Women's Club in the City of East
Palo Alto on November 7, 1991. A thirty day public comment
period on the RIfFS Report and the Proposed Plan ran from Novem-
ber 1, 1991 to December 2, 1991. On Wednesday, November 20, 1991
another notice was published in the Peninsula Times Tribune an-
nouncing extension of the public comment period from December 2,
1991 to December 9, 1991. A presentation of the proposed final
cleanup plan was made at th~ February 19, 1992 and. January 15,
1992 Board Hearing and the November 7th public meeting. Repre-
sentatives from the RWQCB EPA, Rhone Poulenc, and contractors at~
tended the pUblic meeting. The RWQCB staff answered questions
about problems at the site and the remedial alternatives under
consideration. A response to the comments received during this
period is included in the Responsiveness Summary, which is part
of this. Record of Decision.
Fact Sheets for the Rhone Poulenc/Sandoz site were mailed to
every known residence in East Palo Alto, local government offi-
cials, environmental organizations and interested individuals.
Fact Sheet 1, mailed in August 1988, was published as four pages
of the East Palo Alto's eight-page City Connection newsletter.
Information in the newsletter announced additional soil borings
and groundwater sampling to be conducted, summarized site risks
and announced future submittal of the Remedial Investigation
report.
A short notice announcing completion of the Remedial Inves-
tigation was published in the East Palo Alto newsletter, The City
Connection in October 1989. A draft Feasibility Study/Remedial
Action Plan was submitted on August 28, 1989. Fact Sheet 2 was
distributed to the community in January 1990. This Fact Sheet
announced a January 30, 1990 public meeting to present the find-
ings of the Remedial Investigation report and update community
members on the status of the project.
29
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Fact Sheet 3 was distributed during May 1991. This fact
sheet announced a community meeting for May 16, 1991 to discuss
an Early Action Removal, change in agency lead status, site divi-
sion into two operable units, and project schedule. A statement
on the Early Action Removal was issued during the first week of
September 1991. This statement provided the community with a
short synopsis of the removal activities and schedule. During
August 1991 a statement was issued announcing temporary work.
stoppage from excavation activities due to the discovery of
unidentified bottles and vials. On September 23, 1991, a state-
ment was issued that announced completion on the removal ac-
tivities. All statements were hand-delivered to city offices and
to the residences situated closest to the site.
Fact Sheet 4, the proposed plan, was issued on November 1,
1991. The fact sheet described the cleanup alternatives
evaluated, explained the proposed final cleanup plan, announced
opportunities for public comment at the Board Hearing of November
20, 1991 in Oakland and the Public Meeting of November 7, 1991 in
East Palo Alto and described the availability of further informa-
tion at the Information Repository at the City of East Palo Alto
Public Library.
30
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4.0
SCOPB AND ROLB OF TBB RBSPONSB ACTION
This ROD addresses the Upland operable unit which includes
the area delineated in Figure 1.2, and consists of contaminated
soils, groundwater and surface water. This action addresses the
principal threat at the site. The purpose of this response is to
prevent any further horizontal migration of contaminants in the
groundwater, prevent possible future exposure to the public of
contaminated groundwater, prevent contamination of the drinking
water aquifer, and to prevent exposure to contaminated soils.
The response actions will be performed to meet the final site
treatment standards listed in Table 4.1. These levels are based
on Applicable or Relevant and Appropriate Requirements (ARARs)
and health protection criteria for soils.
Approximately 40 chemicals, including heavy metals and low
levels of pesticides and organics, were detected in the soils,
groundwater, surface water, and air at the site (see Table 4.2).
For the upland operable unit, five chemicals have been identified
as the primary contaminants of concern in the groundwater and
soil. These contaminants are arsenic, cadmium, lead, mercury,
and selenium. Arsenic is a human "carcinogen; cadmium and lead
are probable human carcinogens; mercury is not classified as to
human carcinogenicity; and epidemiological studies in humans do
not suggest that excess exposure to selenium is associated with
an increased risk of cancer. Cleanup standards have been as-
signed to all five chemicals.
The selected remedy presented herein addresses the docu-
mented potential threats from the site in the Upland Operable
unit. containment of the contaminated groundwater will sig-
nificantly reduce further migration of contaminants into a
seasonal wetland. Although treatment of contained soils will not
reduce arsenic toxicity, treatment will reduce the mObility of
contaminants. Although, treatment of contaminated soil is
driven by arsenic contamination cleanup standards for all con-
taminants of concern shall be met. The final cleanup standards
for the suite of chemicals detected in soils equate to a in-
dustrial/ commercial use scenario and caicinogenic risk level for
soil ingestion and inhalation of 1 x 10- .
SOIL COB'.rAlUDTIOH
There are currently no ARARs established for cleanup levels
in contaminated soil. The highest concentrations of contaminants
detected in soils are: arsenic (54,000 mq/kq), cadmium (1,500
mg/kg), lead (13,000 mg/kq), mercury (1,900 mg/kg) and selenium
(1,000 mg/kq). Table 4.3 shows estimated volume of contaminanted.
soil in the upland operable unit. Rhone Poulenc submitted a
Baseline Risk Asses~ment within the Remedial Investigation
31
-------
..
-.
Report. EPA and the RWQCB disapproved Rhone Poulenc's risk as-
sessment. PRC Management Inc. under contract to EPA developed a
baseline risk assessment and developed health-based standards for
chemicals of concern in soils at the site..
GROUNDWA~ER CONTAMINATION
contaminated groundwater flows in a south to southwestern
direction along the hydraulic gradient of the shallow zone poten-
tiometric surface. The highest concentrations of contaminants in
the groundwater are: arsenic (460,000 ug/l) , cadmium (31 ug/l),
lead (9 ug/l), mercury (13 ug/l surface water) and selenium
(6,400 ug/l). The circumference of the plume is approximately
3,000 feet. Groundwater in the deep aquifer does not currently
contain elevated levels of contaminants. Groudwater cleanup
standards would apply in the deep aquifer groundwater zone be-
cause it is a potential source of drinking water. Deep aquifer
groundwater shall be maintained at background for arsenic, cad-
mium, lead, mercury, and selenium. Table 4.4 identifies back-
ground levels for the contaminants as they were presented in the
Remedial Investigation Report.
The site has a perimeter monitoring well network located ap-
proximately 100 feet from the. SO ppb arsenic groundwater contour
line. Groundwater in these perimeter wells will not be permitted
to exceed the arsenic MCL of SO ppb. A contingency plan is set
up so that a concentration of 30 ppb of arsenic triggers stepped
up monitoring and 40 ppb of arsenic (based on a statistically
significant sampling) triggers a requirement to pump and treat
the contaminant plume for containment purposes.
.
;~
The shallow groundwater is not currently considered a source
of drinking water. The federal criteria for underground drinking
water sources are outlined in 40 CFR 143. It states:
"Underground source of drinking water (USDW) means an
aquifer or its portion:
(a)
(1)
(2)
Which supplies any public water system; or
Which contains a sufficient quantity of
groundwater water to supply a public water
and
(i)
system;
currently supplies drinking water for human
consumption; or
(ii) contains fewer than 10,000 mg/l total dis-
solved solids; and-
(b) Which is not an exempted aquifer."
The shallow aquifer is not purrently being used to supply a
public water system. The total dissolved solid (TDS) concentra-
tions in the shallow groundwater zone ranges from 570 mg/l up-to
30,000 mg/l. TDS concentrations in the upper shallow zone is
generally less saline than the lower part, and average 3000 mg/l.
32
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The TDS concentrations in the upper zone range from 7,200 to
27,000 with a median concentration of about 17,000 mg/l. The
shallow aquifer does not meet federal criteria for a drinking
water aquifer. Containment of this contaminant plume is neces-
sary. The installation of a slurry wall with maintenance of an
inward hydraulic gradient will prevent horizontal migration of
the contaminant plume.
The groundwater cleanup standards for the Rhone Poulencl
Sandoz site are based on Environmental Protection Agency (EPA)
maximum contaminant levels (HCLs), California Department of
Health Services (DBS) HCLs (proposed or adopted), DHS Action
Levels and ATSDR Toxicological Profiles for arsenic, lead, and
cadmium.
33
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TABLE 4.1 PROPOSED CLEANUP STANDARDS
1990 BAY ROAD SITE. EAST PALO ALTO
CHEMICALS
OF CONCERN'
BACK-
GROUND
(mg/kg)
CLEANUP
STANDARD
(mg/kg)
RISK PARAMETERS
ONSfTE': Based on Commercial/Industrial use scenario with Inhalation, tngestion
exposure pathways
Lead(B2)d
50
450*
Arsenic(A)
20
500
Cadmium(BI)
1.5
1,000
Mercury(D)
300
Sdenium
6,000
Total Excess Cancer Risk (rounded)
Segregated Noncarcinogenic Risk Renal (Cd + Hg)
Neurologc (Pb + Hg)
Dermal (As)
Off si it': Based on Residential future use scenario with Inhalation, Ingestion exposure
pathways
Lead(B2)
50
I20«
Arsenic(A)
20
70
Cadmium(BI)
1.5
250
Mercury(D)
100
Selenium
2,000
Total Excess Cancer Risk (rounded)
Segregated Noncarcinogenic Risk Renal (Cd + Hg)
Neurologc (Pb + Hg)
Dermal (As)
NOTES:
a) See Appendix K. Remedial Investigation Report
b) Most health-protective standards calculated for Industrial and residential hnd use scenarios, based on carcinogenic or
noncardnogenlc effects.
c) Oru'rte includes the operating Sandoz Plant property.
d) Parenthetic notation is carcinogenic classification.
e) Based on EPA's preferred method. Lead Uptake/Biokinetic (BKU) model (Version 0.5. April, 1991).
f) Based on inhalation exposure pathway only.
g) Risk management decision not to include selenium In segregated risk because of low concentration in soil, low degree
of toxic effect to humans, and beneficial antigonistic interaction with other chemicals of concern.
h) Contribution of lead to neurologic effects cannot be quantified in terms of Hazard Index.
0 Offsite Includes adjacent Bains. Curaccio. Rogge. Oemeter. PG&E and Gty of East Palo Aho properties.
34
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TABLE 4.2
:J.
I
,
,
GROUNDWA'IER (mg/I) SURFACE WA'TER
(IDI/I)
Ptequeacy Range of A~&'C Preq Range 01 Avcnp
Qcmical of Detected Coacca 01 Dctcctcd Coacea .
~ CoaccIWatioas Detect Ccacea
AIumialUll l/U 0.4 OA 0/1
Aatimofty 13/35 O.oos . Cl.61 0.1 1/1 .on .Q33
AIseGic 432/484 o.ocm -.c60 rr 44/44 JI012 - 15 2.S
Barium 10/U 0.2 - 0.4 D.33 0/1
Cadmium 6IJ/173 0.0001 - 0D31 0.01 SID .DOO1 - .DOl3
JIOZ3
Calcium U/12 26 - 840 260 1/1 310 310
OIoroCOtID 9/86 .002 - .rm .ot4 0
CobIlt 1/13 0.001 - om 0JI04 1/1 J»5- .oos
~ 48/139 osm - 0.18 Q.03 6fIB .ems - .0281
.Q86
DDT. DDE, DDD O/U 0 . .
Dibut,tphtaJale IfJ4 .002 JI02 0
D~phdlaJate IfJ4 .as .as 0
1,2-Dicb1oI'OCtbaDe 8/86 .tI03. .D32 .ot6 0
l,2-DicbJorocth,ac 4/86 .01 -.1 .11 0
Preoa 113 0/86 0
bon 6/U 0.16 - Z9 9.8 1/1 .os .os
Lca4 1/138 0.009 0JJ09 3fU .DOl -.tI03 .em1
LiacSue OjU 0
Magaaium .12/U 14 . 1100 36IJ 1/1 1100 1100
Manpl1CSC 13/13 0J)6 . 14 2.7 1/1 ~ ~
MCICUI)' 0/138 4fU .oocn - ..ooasa
.oot3
Nic:kd 14/35 0.D03 - LIS 0.18 1/1 JJ7!J J129
Nitrosodiplleaytamiae 1/30 .1)02 JI02 0
Potassiua 12/U G.33 - ZSO 68 1/1 310 310
Setcaium 150/186 0.0001 - 6.4 0.18 17/18 .0001 -:n .011
Silver 9/34 0.0001 - 0.0015 0.0059 1/1 .oooa .oooa
Sodium 12/U 44 . 9300 3300 1/1 10000 10000
Tetrach1oroethylCDe 25/86 .002 . .7 .11 0
T'm 3/U 0.024 - 0.Q33 0.Q3 0/1
Trich1oroethytCftC 35/86 .002 -.7 . .1 0
Vanadium 10/U 0.002 - o.t 7 0.05 1/1 .036 .oJ6
Zinc 51/138 0.01 - 0.279 0.07 5/18 .01 -.G4 .026
Notes:
1. Only dlcmicals on U.s. SPA', Target Compound List that were ctetected at the site are listed.
2.. Avcrage concentrations are the calculated mean ror results above the detection limiL
35
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TABLE 4.2 (continued)
. ,
:',
SOIL . AIR. (mg,lm~
(mg/q)
PrequClK)' Range of A~ Prequency Range of A~nge
Olcmical or Dcteclcd CoaccAtntioo of Detected Coacca
De~oa Conceatntioas Dctcctioa Coacca
Alumiaum 11/11 8700 - 16000 13000 0
AAtimoay 0/11 0
ArscIIic 1190/1409 0.1 - S4000 1100 U/1B 3.6B-7 - .ooos .0001
BariWD 11/11 24 - 230 12.0 0
CadmiWD 93/109 0.2 - 1500 63 5/U 2.48-7 - 6.38-7 ".58-7
Calcium 11/11 1100 - 27000 11000 0
CI1oIo(orm 0/11 0/4
Cobalt 11/11 72 - u.D 896 0
Copper 51/53 13.0 - %ZOO 147 5/10 .DOOID4 - moo67
.ooot16
DDT, DDB. DDD 11/36 o.ozs - 13A 1..4 2
DibutyiphtaJatc 0/36 0
Dicth)'lphtbalatc 0/36 0 ..
1,2-Dich1oroctha11c 0/11 0/4
1,2-I)ida1oroctylcae 0/11 0/4
Pteoa 113 0/11 2/4 .1:101 -.oos JJQ3
IroG 11/11 10000 - 22000 17000 0
Lead 118/144 2 - 13000 610 6/17 2.08-6 - JI03 .OCJO:S1
Lindanc 0/36 2/2 .000011 - .000017
.ooocrn
MagDc:ciam. 11/11 4200 - 6SOO 5100 0
Manganese 11/11 220 - 390 300 0
Mcmuy 93/1(JIJ 0.04 - 1900 54 5/12 LSB-7 - 3.78-7 2..68-7
N"1CIteI 11/11 34 -53 39 0
Nitrosodipheoylaminc 0/36 0
Potassium 11/11 520 - 2200 1200 0 .
Selenium 98/135 0.1 - 1000 28 O/U
SiMr 1/11 o.s o.s 0
sOdium 11/11 480 - 6SOO 1460 0
Tetrachloroethytcnc 0/11 0/4
Tin 3/11 0
Tridllorocthyleae 0/11 0/4
Vanadium 11/11 1.8 - 41.0 n 0
Zinc 51/53 34 - S400 510 0/5
NOTES: L Only chemicals on U.s. EPA's Target Compound List that were detected at the site are listed.
2. AY'Crage conceAtrations arc the ealculated mean for results aboYC: the detection limit.
36
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Table 4.3
ESTl1\fATED VOLUME OF CONTAMINATED SOIL
UPLAND OPERABLE UNIT
1990 Bay Road Site
East Palo Alto, California
Volume of Soil (yd') with Arsenic Concentrations
Greater than'
Property Owner
20
mglkg
135 .
mglkg
500
mg/kg
1000
mglkg
5000
mglkg
- .
Unpaved North Area 23,000 9,600- 5,000 3,000 800
Railroad Track Area 8,000 4,700 2,500 - 1,300 6?-0
Sandoz Total: 79,000 39,000 19,500 10,800 2,200
Bains Property
Parking Areas . 1,500 100 .25 10
Bains Total: 3,500 470 190 100
Curtaccio ~es: 1,500 360 35 20
Rogge Property: 210 6 --b-
j
Demeter Properties: 580 35
Bay Road: 2,600 450 20
PG&E Poleyard: 3,900 200 ---
TOTAL FOR UPLAND 91,000 - 40,500 20,000 11,000 2,200
OPERABLE UNIT (rounded):
Notes:
1. Method of calculation presented in RI Report (Geomatrix and SSP &A. 1989).
2. Shading indicates affected soil that is inaccessible until operations cease and structures are removed.
37
PI ZJlNtfS.MT1l.T1IL
-------
~
i
~
TABLE"." GROmmWA'l'ER CLEANUP STANDARDS FOR DEEP -AQUIFER
Chemical
Background
Concentration
ug/l
MCL or
DHS Action
Level
ug/l
- -
ARSENIC 2.0 50
CADMIUM 1.0 5
LEAD 1.0 to 100 15*
MERCURY < 0.5 2
SELENIUM < 100 50 *
ANTIMONY < 100 5*
* Background concentration shall be set to MCL.
38
-------
5.0
SUMKARY OF SITE CHARACTERISTICS
5.1
SOURCES OF CONTAMINATION
The Remedial Investigation focused on the distribution of
arsenic and other compounds on the u.s. EPA Target Compound List
in soil, groundwater, and surface water at the site. Arsenic was
determined to be the primary contaminant of concern. Arsenic
concentrations are almost always higher than concentrations of
the other compounds, is more widespread, appears to be more
mobile in groundwater than other contaminants, and the relative
risk associated with arsenic is much higher. .
The soil and groundwater investigations identified three
primary areas where releases of arsenic compounds occurred.
These three areas are: the location of the former underground
mixing tank; the former sludge pond area, and along the railroad
spur. Surface water runoff from the Sandoz property to the ad-
jacent low-lying areas to the south and east was the major
transport mechanism for redistribution of arsenic and other con-
taminants. contaminants are present in the near-surface soil in
the low-lying areas west of the levee constructed after 1955. .
The levee prevented surface water runoff from reaching the tidal
marsh. The average background arsenic concentration in soil at
the site is about 9 milligrams per kilogram (mg/kg). The
qualitative assessment suggests that if the arsenic concentration
in a soil sample exceeded 20 mg/kg it was impacted by site ac-
tivities.
5.2
DESCRIPTION OP CONTAMINATION
GROUNDWATER
Rhone Poulenc has installed and sampled eighty-four monitor-
ing wells in the vicinity of the site to define the extent of
groundwater contamination (see Figure 5.1). Fifty-eight of these
wells are useful for defining the extent and nature of the
groundwater plume. Fourty wells are completed in the upper shal-
low zone (5 to 1S feet bgs), seventeen are completed in the lower
shallow zone (20 to 3S feet bqs), and one well is. completed in
the upper part of the deep aquifer (170 feet bgs). EPA and the
State of California have determined that groundwater in the shal-
low aquifer is not a potential source of drinking water because.
39
-------
total dissolved solids concentrations exceed both federal and
state criteria for determining underground sources of drinking
water.
~
Groundwater flow in the shallow aquifer is towards the
south-southeast, but on-site flow toward the west and northwest
have also been measured (see Figure 5.2 and 5.3). Groundwater
contamination has been shown to occur in the lower shallow and
upper shallow aquifer within an 11-acre area. Figure 5.4 and 5.5
shows the average arsenic and selenium concentrations in the
shallow aquifer. The circumference of the groundwater plume is
about 3,000 feet.
Wells that contain high arsenic concentrations are in the
vicinity of the former sludge pond, and wells which are located
adjacent to the former underground mixing tank. Soils in the
vicinity of these wells are some of the most contaminated soils
at the site. Only three of the seventeen wells in the lower part
of the shallow aquifer exceed the arsenic MCL' of 50 ppb. The
well with the highest average arsenic concentration, 230,000 ppb,
is located in the center of the former sludge pond (screened in-
terval at 20 to 37 feet); the well with the next highest arsenic
concentration, 1,200 ppb is located adjacent to the mixing tank
(screened interval at 25 to 39 feet); and the other well with an
arsenic concentration of 350. ppb is located about 150 feet
downgradient of the mixing tank (screened interval at 24 to 36
feet). The concentrations of arsenic, selenium, antimony, and
cadmium exceed their MCLs.
A perimeter monitoring well system encircles the groundwater
plume,' and will detect any significant migration of the
groundw~ter plume (see Figure 5.6) radially outward in all direc-
tions from the site. The perimeter monitoring wells are within
100 feet of the 50 ppb arsenic contour line. The concentration
of contaminants within these perimeter wells shall not exceed the
arsenic MCL.
SURFACE WATER
Surface water ponds seasonally in the low-lying areas to the
south (Call-Mac property) and east (Non-tidal marsh on PG & E
property) of the site. This seasonally ponded surface water con-
tains elevated concentrations of arsenic, 'copper, and selenium.
Concentrations of lead, mercury, and zinc were at background
levels. Water quality in the tidal marsh east of the site will
be evaluated in the Ecological Assessment for the site.
40
-------
SOIL
Soil with arsenic concentrations in excess of 20 mg/kg
covers approximately 13 arces of the site. This area includes
five acres on the Sandoz property, 2.4 acres of the Torres
property, 3.3 acres (PG&E) in the non-tidal marsh, 1 acre in the
tidal marsh, 0.8 acres on the properties to the west and 0.6
acres on the properties to the north. The vertical extent of
soil with arsenic concentrations in excess of 20 mg/kg is
generally less than 15 feet, except near the former underground
mixing tank and the sludge pond locations. In these areas the
vertical extent is as great as 34 feet below the ground surface.
Soil arsenic concentrations up to 54,000 mg/kg have been detected
at the site. Table 4.2 shows estimated volumes of contaminated
soil in the Upland operable Unit.
Figures 5.5 and 5.6 show the
of arsenic contamination. During
senic concentrations greater than
were removed (see Figure 2.1).
horizontal and vertical extent
September 1991 soils with ar-
5000 mg/kg in accessible areas
5.3 CONCLUSJ:ON
Data used to develop the Feasibility Study, to select
remedial alternatives and to develop conclusions and clean-up
standards presented in this Record of Decision were based on the
following data quality requirements:
:J
i
2)
4)
5)
1)
All data were collected under the guidance of a Quality
Assurance Project Plan developed under EPA protocols
and reviewed and approved by California Department of
Health Services Quality Assurance Management staff.
All data were collected in accordance with procedures
presented in an approved Sampling and Analysis Plan.
The Sampling and Analysis Plan was developed in accor-
dance with EPA Region 9 guidance and were reviewed and
approved by EPA staff. .
3)
Random sample splits were collected by Board staff to
confirm the validity of data generated.
Selected data was validated by the Department of Health
Services and found to be qualitatively and quantita-
tively acceptable.
There has been reasonable repeatability of the data
based on years of monitoring.
41
-------
+
N
W-120
W-110
W-lU @
.:
. .
@
W-103
WBEK.S snumr
----..
Explanation
Monitoring Netwodc wcUs:
@ Upper shallow zone perimeter montoring wells
13 Lower sba110w zone perimeter montcring wells
£ Deep aquifer well
. Oth« upper sbaJlow zone wells
. Other lower sbaJlow zone wells
OIh«wel1s:
'* Other upper shallow zone wells
<> Other lower shallow zone wells,
~ Area with Arsenic> 0.05 mgll in ground water
o
I
Scale
250
500
. I
feet
@D
S.s. PAPADOPULOS & ASSOCIATES. INC.
Q)NSULTINO (]ItOU}ID.W 411!Jt 1i'n>ROLOO1STS
~
FIGURE
5 _:1
.J-,
.~\
LOCATIONS OF WELLS
, ."
.'
~:
",
42
-------
+
N
Q
;i
~
. .
WEEKS snEE1'
~
Explanation .
MonitOring Network wc11s:
e Upper sb.a11ow zone perimeter montoring wells
. Other up~ shallow zone well .
Other weUs:
. Other upper shallow zone wells .
U4i WaJJ:r level measured in well (feet above MSL)
mu Area with Arsenic> 0.05 mgJI... in ground water
o
I
Scale
2SO
soo
I
feet
6D
S.s. PAPADOPULOS &. ASSOCIATES, INC.
CONSULTINO GIlCIUND-W AT1IIlHYDAOLOOISTS
CONTOUR MAP OF JUNE 1990
WATER LEVELS
UPPER SHALLOW ZONE
FIGURE
5.2
43
-------
+
N
NR.
NR~
-=
cum
... C1.OO1
QJD Upper sbaUow zonc perimeter montaring wells
8 Lower shallow zooc perimeter montoring wells
. Other upper sha110w zone wells
. 0d1er lower shallow zone wells
Other wdls:
.. Other upper shallow zone wells
<> Other lower shallow zone wells
o.as Average Arsenic concentration detected in well (mgIL)
NIt Averagc Arsenic concentration detected less than 0.001 mg/L
o
I
Scale
2SO
S()()
I
feet
@D
5.s. PAPADOPULOS & ASSOCIA1ES, INC.
Q)NSU!.'t1I(O GIlOUHO-W" 11IIlHYDROLOOISTS
FIGURE
AVERAGE CONCENTRATION
OF ARSENIC IN SHALLOW AQUIFER
5.3
.~~
..'
:!:
44
-------
:.t
-+
N
.:
" .
WEE1tS ST1U!Bl"
~
,
Explanation
Monitoring NetwOtk wells:
(!) Upper shallow zone perimeter montoring weDs
(!] Lower shaUow zone perimeter montaring wells
£ Deep aquifer weU
. Other upper shallow zone weDs
. Other lower shallow zone weDs
Other weDs:
. Other upper shallow zone weDs
o Other lower shallow zone weDs
~ Area with Arsenic> 0.05 mg/1 in ground water
o
. I
Scale
2SO
soo
I
feet
@D
S.s.PAPADOPULOS & ASSOCIATES, INC.
OJNSUt.t1NQGtlO~WA.~K~1STS
FIGURE
PERIMETER MONITORING WEil..S
5.4
45
-------
-0
08
~~::I
0()
~.:: (::
)::\. »
'~_I L::
.~~
'J,~
", '. ~: ..'"
.'.--------.-.--
:J "I
.1
I' ",.. i,
~.,...
KEY
l.
'::')
. (.\. .
'" c:. (:.\.;
'\,l~:~;I"~. .'
r"
:.J
""', .
)
.....':.1
...
. --..-=--~~' ,
..
-
j
o
I
200 Feet
I
...
46
Contours dell.ltlng Irel
containing loll concentr.tlons In'
excess or libeled concentr.tlon
lilli/kg)
Hote
Contours blsed on soil boring dltl
presented In Appendices D .nd £.
A~'A .
",.. .....a
G
i
CONTOURS Of SOIL ARS£HIC CONC£HTRATIOHS
1990 DIY ROld Site Ind Vicinity
rllt P.lo Alto. CIIHornl.
~
a8GMA.T1I8,8(
5.5
'10."
-------
""\7
08
~ ;;\:J
0.0
:;(-.: c
» »
r- .-
~
':' I.'
"/
I
"I
I -
,L----~--~"-"---I!I~. ...~.
11.,,-.,'
-
~
"".. I'
,,,.. ...,..
G):~
r-'
.I.J
-....."'''''.
.....-. .--
......-.
nl
J1
Rcvlled ZlU/O'
,
I
J:ET
Contour of appro~llate depth In .
feet of soil containing greater.
than ZO mg/kg arsenic
Hote
Contours based on soil boring data
presented In Appendices 0 and E.
t
o
I
200 feet
J
VERTICAL EXTEHT Of SOIL WITH ARSEHIC
COHCEHTRATIOHS GREATER TI"" 20 ~/k,
1"0 8ay Road Site and Vicinity
rast 'alo Alto. California
~
..~,......c
-------
6.0
SaHHARY 07 SITS RISKS
Rhone pou1enc prepared a baseline risk assessment as chapter
five of the Remedial Investiqation report dated September 19,
1989. This risk assessment assessed the cumulative carcinogenic
risk and non-carcinoqenic hazard quotient for a reasonable maxi-
mum exposure for current land use. Receptors considered were
on-site workers, neighboring residents, recreational visitors,
construction workers, and site trespassers. Agency personnel
reviewing this risk assessment noted a number of problems with
the calculations as they were presented. It was agreed that
Rhone Poulenc would revise risk calculations in an appendix to
the Feasibility Study. As a result of problems associated with
the Risk Assessment, the approximate calculations were made in a
document submitted by EPA's contractor on February 18, 1992.
6.1
CO)1'J.'AKIDH'l' %D~J:PJ:CATJ:OB
Approximately 40 chemicals were detected on site in soils,
groundwater, surface water and air. The chemicals that pose a
significant hazard at the site were identified by following a
series of steps recommended in the "Superfund Public Health
Evaluation Manual" (SPHEM) dated October 1986, and the Region IX
Superfu~d Risk Ass~ssment Guidelines dated 18 August 1988, which.
were acceptable guidance documents at the time. Based on these.
guidance documents a first cut analysis was performed to
eliminate chemicals which were 1) present at background con-
centrations; 2) present in not more than two media above back-
ground ~ut below appropriate regulatory criteria or standards; 3)
present above regulatory criteria but not widely distributed
throuqhout the site; and 4) no route for human exposure existed.
The following five chemicals of potential concern were iden-
tified within the Study Area: arsenic, cadmium, selenium, mercury
and lead. Arsenic, cadmium, selenium, mercury and lead were con-
sistently detected in the samples collected throughout the plume
area. Table 4.2 lists detection freqencies, average concentra-
tions, and maximium concentrations for all site compounds indlud-
ing chemicals of concern.
EPA assigns weight-of-evidence classifications to chemicals
that may be potential carcinogens. Under this system, chemicals
are classified as either Group A, Group B1, Group B2, Group C,
Group D, or Group E. Group A chemicals (known human carcinogens)
are agents for which there is sufficient evidence to support the
causal association between exposure to the agents in humans and
cancer. Groups B1 and B2 chemicals (probable human carcinogens)
are agents for which there is limited (B1), or inadequate (B2)
evidence of carcinogenicity from human studies, but for which
there is sufficient evidence of carcinogenicity from animal
studies. Group C chemicals (possible human carcinogens) are
agents for. which there is limited evidence of carcinogenicity in
49
-------
animals, and Group D chemicals (not classified. as to human car-
cinogenicity) are agents with inadequate human and animal
evidence of carcinogenicity or for which no data are available.
Group E chemicals (evidence of noncarcinogenicity in humans) are
agents for which there is no evidence of carcinogenicity in ade-
quate human or animal studies.
For the Rhone Poulenc site one of the chemicals of concern
is a carcinogen, and two are potential carcinogens. Arsenic was
identified by EPA as a human carcinogen (Group A) based on avail-
able laboratory animal data. Cadmium and lead were identified by
.EPA as probable human carcinogens (Group B1 and B2) based on
available laboratory animal data. Mercury remains unclassified
as a potential carcinogen because there is inadequate evidence of
its carcinogenicity in animal studies. Selenium's epidemiologi-
cal studies in humans do not suggest that excess exposure is as-
sociated with an increased risk of cancer.
EXPOSURE ASSBSSHBHT
The perinent exposure pathways identified were ingestion of
soil and inhalation of soil particulates. The dermal contact to
the soils pathway was not evaluated because metals are not ex-
pected to be readily adsorbed through the skin.
~
TOXXCITY ASSBSSHBHT
Arsenic is considered to be a rare but ubiquitous element
with an .average crustal abundance of 2-5 ppm. Arsenic has an ex-
tremely complex chemistry, with stability in four oxidation
states under naturally occuring pH and oxidation potentials (Eh).
This range of valences, and factors influencing valence transfor-
mation, are extremely important in determining toxicity. For
example, As III and As V are the most toxic and the +3 state-is
much more toxic than the +5 state. Some factors influencing ar-
senic valence include ph, temperature, salinity, and metal sul-
fide and sulfide ion concentrations. Due to arsenic's chemical
similarity to phosphorus it interferes with human biochemical
reactions involving the phosphorous. Chronic exposure to arsenic
by ingestion or inhalation causes a variety of cardiovascular,
central and peripheral nervous system and dermal disorders, such
as skin hardening and cancer.
Cancer potency factors (CPFs) have been developed by EPA's .
Carcinogenic Assessment Group for estimatinq excess lifetime can-
cer risks associated with exposure to potentially carcinogenic. .
chemicals. CPFs (currenily slope factors), which are expressed
in units of (mg/kq-day)- , are mUltiplied by the estimated intake
50
-------
of a potential carcinogen, in mg/kg-day, to provide an upper-
bound estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects
the conservative estimate of the risks calculated from the CPF.
Use of this approach makes underestimation of the actual cancer
risk highly unlikely. Cancer potency factors are derived" from
the results of human epidemiological studies or chronic animal
bioassays to which animal-to-human extrapolation and uncertainty
factors have been applied. The oral and inhalaiion cancer
potenrY factor for arsenic was 1."8 (mg/kg-day) - and 15 (mg/kg-
day)-. The inhalation cancer potency factor for cadmium was 6.1
(mg/kg-day)-l. A oral cancer potency factor °is not available for
cadmium.
Reference doses (RfDs) have been developed by EPA for in-
dicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals. Es-
timated intakes of chemicals from environmental media (e.g., the
amount of a chemical ingested from contaminated drinking water)
can be compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors
help ensure that the RfDs will not underestimate the potential.
for adverse noncarcinogenic effects to occur. The RfD's for the"
five chemicals of concern are listed below;
Chemical
Oral RfD
(critical Effect)
Inhalation RfD
(critical Effect)
Arsenic
Cadmium
Lead
Mercury
Selenium
1.0E-03
1.0E-03
1.6E-04*
3.0E-04
3.0E-03
NA
NA
NA
8.6E-05
NA
* The oral RfD for lead was based on a MCL level of 5 parts per
billion (ppb) and the following intake assumptions: an inges~ion
rate of 2 liters of water per day and an average body weight of
70 kg.
6.2
RISK CBABAC'J.'BR:IZATIOH
Excess lifetime cancer risks are determined by mUltiplying
the intake level with the cancer potency factor. "Tbese risks are
probabilities that are generally expressed in scientific "
notation(e~g., 1 x 10-6 or 1E-6). An excess lifetime cancer risk
of 1 x 10- indicates that, as a plausible upper bound, an in-
dividual has a one in one million chance of developing cancer as
a result of site-related exposure to a carcinogen over a 70-year
51
-------
lifetime under the specific ~xposure conditions at a
carcinogenic risk of 1 x 10- is equal to one excess
of cancer in a population of 1000. EPA's acceptable
risk range for clganup standards selected. for a site
in 10,000) to 10- (1 in 1,000,000).
site. A
occurrence
C?arci!!2genic
1.S 10 (1
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminant's reference dose). By adding the HQs for all con-
taminants within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can
be generated. The HI provides a useful reference point for gaug-
ing the potential significance of multiple contaminant exposures
within a single medium or across media. If the noncarcinogenic
Hazard Index is less than one, EPA considers the combined intake
of chemicals unlikely to pose a health.risk.
Due to the lack of 95th upper confidence limits of the
arithmetic mean, only average or maximum concentrations were used
in estimating the baseline cumulative health risks for the
residential and commercial/industrial scenarios. The residential
scenario, using average concentrations for arsenic and cadmium
showed a risk of 2 x 10-3 and a hazard index of 2.5 with arsenic
contributing 99.9 percent of the carcinogenic and noncarcinogenic
risk. The residential scenario, using maxim~ concentrations for
arsenic and cadmium showed a risk of 8 x 10- and a hazard index
of 121 with arsenic contributing 99.9 percent of the carcinogenic
and non-carcinogenic risk.
Thus the carcinogenic risk and Hazard Index associated with
a "no action" remedy exceed EPA's acceptable carcinogenic risk
and Hazard Index range. Table 6.1 provides the calculation of .
baseline cumulative health risks associated with exposure to the
upland soils.
The carcinogenic risk and noncarcinogenic hazard at the
cleanup standards associated with the ingestion of soils and in-
halation of heavy metals using the maximum exposure scenario ~s
shown on Table 6.2. The selected remedy is protective of human
health and the environment -- as required by section 121 of
CERCLA -- in that contamination in soil is treated to at least
these health-based standards and falls within EPA's acceptable
carcinogenic risk range (10-6 to 10- ) and noncarcinogenic Hazard
Index. of less than one.
6.3
PUSBHCB OP SBHSXT:IVB HtJJIAJI POPULAT:IOBS
In order for a chemical to. pose a human health risk, a com-
plete exposure pathway must be identified. The greatest poten-
tial for exposure to chemicals at the site would be from residen-
tial uses. The BPH~ did not identify potential exposure pathways
52
-------
under current land use conditions and did not identify sensitive
human populations. The closest residences are approximately 500
feet southwest of the site. Although several elementary schools
located in the area, the closest school is Ravenswood Children
Center (grades K-5, approximately 185 students) which is located
. at 1286 Runnymede Avenue. There are no day care centers or con-
valescent homes located in the immediate vicinity of the site.
6.4
PRESENCE OF SENSITIVB ECOLOG:ICAL SYSTBHS
In May 1990 Rhone Poulenc submitted an Ecological Assessment
Workplan. This Workplan was designed using the EPA guidance
document entitled Ecological Assessments of Hazardous Waste
Sites: A Field and Laboratory Guide. This workplan was designed
to address migration of contaminants into the tidal marsh and
non-tidal marsh located adjacent to the site.
The overall goal of the workplan was to collect very
detailed sediment quality, water quality, and bioassay data, as
well as additional physiological bioaccumulation, and population
and community data. The study will also generate a certain
amount of data on ecosystem productivity.
. WE'1'LUDS
ROH-TIDAL DRaH
The non-tidal marsh is a disturbed environment that is
seasonnaly flooded. In the low-lying portion of the marsh
seasonally ponded water is acessible to and attracts water-
oriented birds during portions .of the year. Plant life is patchy
within this area and consists largely of the salt-tolerant salt
grass (Distichlis spicata) with lesser amounts of sea-blite
(Suaeda californica) and picklweed (Salicornia virginica). Other
species observed in the non-tidal wetland include fathen
(Atriplex patula var. hastata), alkali heath (Frankenia
grandifolia), ryegrass (Lolium spp.), rabbit's-foot grass
(Polypogon elongatus), sand-spurrey (Spergularia marina), and
dock (Rumex spp.). -
'l:IDAL HARSH
The tidal marsh east of the levee is a mid to upper-
elevation tidal marsh approximately 1,800 feet west of the tidal
mudflats of southern San Francisco Bay. Elevations of the marsh
range from about 3.5 to 6.5 feet (NGVD). The marsh floods durinq
higher spring tides and winter storms. The plant community is
dominated by picklweed (Salicornia virginica) and salt grass
(Distichlis spicata), with Pacific cord grass (SPartina foliosa)
denser in lower elevation areas. and tidal channels, and gum-plant
(Grindelia humilis), fathen (Atriplex patula var. hastata),
alkali heath (Frankenia grandifolia), and jaumea (Jaumea carnosa)
in slightly higher ~levation areas. The marsh vegetation is
53
-------
classified as estaurine, intertidal, emergent, and persistent in
the u.s. Fish and Wildlife service National Wetlands Classifica-
tion system.
The marsh is flooded and drained by several small tidal
channels lined with cordgrass. The sidewalls and bottoms of the
channels are rich in benthic organisms, and are typical of many
such tidal channels in the south San Francisco Bay. Included
among the typical channel bottom benthic organisms are the Baltic
clam (Hacoma balthica), the ribbed mussel (Ischadium dimissum),
and the yellow shore crab (Hemiqrapsus oregonensis). A
moderately sized benthic population with a diversity and species
composition typical of the south Bay was found.
The shallow tidal channels at the site also provide food and
protection for juvenile fish and other small non-game fish. The
topsmelt(Atherinops affinis), arrow goby (Clevelandia ios) , and
stickleback (Gasterosteus aculeatus) are species observed and/or
collected during the ecological assessment field work.
~
Two endangered species are reported to use South San Fran-
cisco Bay, located approximately 11 miles northwest of the Study
Area. The California clapper rail (Rallus longirostris ob-
soletus) and the salt marsh harvest mouse (Reithrodontomys
raviventris) are reported to exist in the tidal marshes of the
Bay and bayshore. The endangered California brown pelican is oc-
casionally seen in the Bay Area, but does not nest in the South
Bay. Ranges of the endangered American peregrine falcon and
southern bald eagle include the Bay Area. The southern bald
eagle does not use bay and bayshore habitats, but the perigrine
falcon has started to make a comeback at some northern locations
in San Francisco Bay. Approximately 33 bird species have been
observed drinking, feeding, bathing or roosting in the seasonnaly
ponded areas of the Rhone Poulenc site. Of the 33 species ob- .
served during a four-day period in January 1988, 7 were
shorebirds, 6 were waterfowl, and the remaining 20 were species
of songbirds and raptors. The highest number of individuals
using the site included 98 European starlings, 84.mourning doves,
57 Brewer's blackbirds and 34 red-winged blackbirds.
A Clapper Rail survey was conducted in April 1990. This
study estimated the locations of 21 Clapper Rail pairs and 15
non-paired individuals. The survey results estimated for the
34.4 hectare (85 acre) marsh, a density of 1.66 rails per hectare
(0.67 rails per acre) based upon a population of 57 rails. This
estimate is well above most density estimates for marshes within
San Francisco Bay. During the trapping of surrogate species for
the small mammal study portion of the Ecological Assessment salt
marsh harvest mouse were trapped and released. Hourning doves
(84 individuals), Brewers blackbirds, European starling (98 in-
dividuals) have also ~een observed on site.
54
-------
The results of the Ecological Assessment will be presented
in a report to be submitted in March of 1992 and a final Record
of Decision for the site that will address the Wetlands will be
completed during 1993.
6.5
CONCLUSJ:OH
Actual or threatened releases of hazardous substances from
the Rhone Poulenc site, if not addressed by implementing the
response action selected in this ROD may present an imminent and
substantial endangerment to the public health, welfare or en-
vironment. Based on the fact that a variety of the heavy metals
detected in the study Area pose significant health risks as car-
cinogens. or as noncarcinoqens and complete exposure pathways ex-
ist, EPA has determined that remediation is warranted.
55
-------
TABLE 6.1
BASELINE CUMUlATIVE HEALTH RISKS
ASSOCIATED WITH EXPOSURE TO THE UPlAND sons
Chemical or Chemical Health RJsklHazard (b)
PoteDtIal Coac:em (8) Coacmtratioa Cancer RIsk Huard IDdeE
Residential - Average
Arsenic (A) 1,050 2E-03 2.1
Cadmium (81) 68 2E-06 (c) 0.1
Lead (B2) S90 - BKU (d)
Mercury (D) 6S - 0.3
Selenium 3S - om
!~=~1if6iB__.~t~{i~@.f:~~Tif.~11~~~~~~!ti~~i~f.1 ~Jlw._. ,~~_1'"
Resldeatlal - MaxImum
Arsettic (A) 54,000 8&02 108
Cadmium (81) 1,500 SE.()S (c) 3
Lead (B2) 1,300 - BKU (e)
Mercury (D) 1,900 - 90S
Selenium 1,000 - OoS
;~_mijft.~~.JlW#*fg*t@frF~filiBmi~i~~; ~~J.!4j .. .., .Jiff:N;tWAWiifM,
' »'
,"X:,
CommerdaJJladastri81 - Aftr8ge
Arsenic (A) 1,050 48-04 OOS
Cadmium (81) 68 1E{)6 (c) 0.03
Lead (B2) S90 - BKU (f)
Mercury (D) 6S - 0.1
Selenium 3S - 0.006
~-ilBRii_ii~If~1miB#t~m~w1~~ftif.~it~iil~li1l. .~W~~~~ ~8tt4iIDJ
. "':>"~::: . .:. OJ' ".' ».
:... :@::::.:.~-.MJ.,., "".:,,,1m. .. . -.' "X-..... '''''.I'..~............y.
Commerdal/lDdastri81 - Malmam
Arsenic (A) 54,000 2E-02 27 .
Cadmium (81) 1,soo '3E-05 (c) 0.8
Lead (B2) 1,300 - BKU (g)
Mercury (D) 1,900 - 3.2
Selenium 1,000 - 0.2
~1_'~._~MtBi~1W.Rift.~~r.~1.t1~B :~$iitfiiliW{ti.: -_j!D%t.f&1fl
NOTES:
(a) ParcDtbetic aocatioa GCIt to c:bemic:aIaame is EP A C8I'I:iaopic weipt-d-cvideDoc ..I.-;rlCltioa.
(b) CaDCeI" riM ex' ba:zud iIIda wu C""'''.~ed fex' the iaptiaca of IOiI aad 1nh.I-tioa of putkaJates pathways.
(c) &.cess caDDCl'rlsk fex'cadmium wu CI''''''I~ fOl'the iDhaIatioa of puticaIata patbw8y 0DIy.
(d) B:ued OIl EPA'. pdem:d IDdbod, the Lead Up&aUIBiotiadic (BKU) model (Venioa o.s.AprilI991).
Comparisoa of S90 IIIIIkc to the preIiaIiIwJ HBO of 2SO m&IkI iDdicates poteadal8Chtene effec:u to c:hiIdraL
(e) Compatiscxl of 1,300 IIIr/kI to the preIimiD8ry HBG of %SO mrJkc iDdic:ata poteaIiaI8Chtene effecu to c:biIdrca.
(f) Comparisoa of 590 ~ to the prdimiDary HBG of 900 mf/1q iDdicates DO poteDtW achene efl'ec::ta.
(g) Compariscxa of 1,300 IIIr/kI to the prdimiDary HBG of 900 mgIkg indicates DOCHIef"lIIitiYe poteatial8Chtene effecu to worken.
56
-------
TABLE 6.2
RECOMMENDED FINAL REALm-BASED GOALS
AND ASSOCIATED CUMULATIVE RISKS
Chemical of
Poteatial CaDeau a
Residential
Arsenic (A)
Cadmium (81)
Lead (B2)
Mercury (D)
Selenium
Total Excess Cancer RIsk
Seeacgatecl NoaeardDogealc Hazard
Commerc:ialllDdDSUial
Arsenic (A)
Cadmium (81)
Lead (B2)
Mercury (D)
Selenium
Total Excess Cancer RIsk
Segngated Noac:ardaogeD1c Hazard
FIDaI Health-based
Goal
Cumulative RlsklHazard
Cancer RIsk Hazard Index
70
2SO
120 (c)
100
000
lE-04
8&06
0.1
0.5
BKU
0.5
1.0 d
Dermal (As)
Neurologic (Pb + IIg)
Reual Ccl +
~W$ijj$?4_Jtl
.""
57
N01ES:
M. Aneaic; Cd - ~-~ Pb - Lad; He - Merc:u,.
(a) Parea&bcdcDOtadcxa DC:It to cbaDicallI8IDe is EPA~...apt-ol-eWk:Dcc "'.-fLo.tWo
(b) Fmal "-I.~ pia - tile IIICIIt bea1tb-protec:tM Y81aes, baed eitbcraa ~riIt«
~ baz8Id babe Iqatiao 0( 80il UId ...".I"iaa 0( puticalatcs JI8dnra78.
(c) Baedoa EPA" pnfancllllClbod, tile Lead UpealrdBiotiDcdc(BKU) IDOdcI (Vcaiaa O.5,Apill991).
(d) Risk ~ deciIioa DOt to iDd1Ide leleaiam ill aqrepted bI:rard becaaIe of ita low CCIIIceIItratio ill IOil,
low dqn:e ol taIic effeda to humaa, aDd ~..,u,' mt8JOGil&ic iIdcr8cdoa with o&bcr' CaOPC.
(c) Coatribatiaa ollead to ~ effec:18 C8IIDOt be cr'....II"-t iD lenDs of H-.t 1ada.
soo .
1,000
450 (c)
300
2E-04
2&OS
~~~Mllr~
Dermal (As)
Neurologic (Pb + IIg)
Reual Ccl +
. .
-.
-------
7.0
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARS)
Under Section 121{d) (1) of CERCLA, remedial actions must at-
tain a degree of clean-up which assures protection of human
health and the environment. Additionally, remedial actions that
leave any hazardous substance, pollutant, or contaminant on-site
must meet a level or standard of control that at least attains
standards, requirements, limitations, or criteria that are
"applicable or relevant and appropriate" under the circumstances
of the release. These requirements, known as "ARARs", may be
waived in certain instances, as stated in Section 121(d) (4) of
CERCLA. .
"Applicable" reqUirements are those clean-up standards, stan-
dards of control and other substantive 'environmental protection
requirements, criteria, or limitations promulgated under federal
or state law that specifically address a hazardous substance,
pollutant or contaminant, remedial action, location, or other
circumstance at a CERCLA -site. "Relevant and appropriate" re-
quirements are clean-up standards, standards of control and other
substantive environmental protection requirements, criteria, or
limitations promulgated under federal or state law that, while
not "applicable" to a hazardous substance, pollutant, con-
taminant, remedial action, location,' or other circumstance at a
CERCLA site, address problems or situations sUfficiently similar
to those encountered at the CERCLA site that their use is well-
suited to the particular site. For example, requirements may be
relevant and appropriate if they would be "applicable" but for
jurisdictional restrictions associated with the requirement. See
the National Contingency Plan, 40 C.F.R. Section 300.6, 1986).
The determination of which requirements are "relevant and
appropriate" is somewhat flexible. EPA and the State may look to
the type of remedial actions contemplated, the hazardous sub-
stances present, the waste characteristics, the physlcal charac-
teristics of the site, and other appropriate factors. It is pos-
sible for only part of a requirement to be considered relevant
and appropriate. Additionally, only substantive requirements
need be followed. If no ARAR covers a particular situation, or
if an ARAR is not sufficient to protect human health or the en-
vironment, then non-promulgated standards" criteria, guidance,
and advisories must be used to provide a protective remedy.
7.1
TYPES OF ARARS
There are three types of ARARs. The first type includes
"contaminant specific" requirements.. These ARARs set limits on
concentrations of specific hazardous substance, contaminants, and
contaminants in the environment. Examples of this type of ARAR
are ambient water quality criteria and drinking water standards.
58
-------
The second type of ARAR includes location-specific requirements
that set restrictions on certain types of activities based on
site characteristics. These include restriction on activities in
wetlands, floodplains, and historic sites. The third type of
ARAR includes action-specific requirements. These are
. technology-based restrictions which are triggered by the type of
action under consideration. Examples of action-specific ARARs
are Resource Conservation and Recovery Act ("RCRAn) regulations
for waste treatment, storage, and disposal.
ARARs must be identified on a site-specific basis from in-
formation about specific chemicals at the site, specific features
of the site location, and actions that are being considered as
remedies.
The ARARs for the Rhone Poulenc site are identified in Table
7.1 and Table 9.10 lists contaminant specific ARARs to be met by
the Rhone poulenc site.
59
-------
. "'-
TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
RHONE POULENCISANDOZ Site
East Palo Alto, California
Page I of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Federal Requirements. Criteria. or Limitations
Safe Drinking Water
Act
National Primary
Drinking Water
Standards
Maximum Contaminant
Level Goals (MCLGs)
~..P" .1IT3
42 U.S.C. t 300f
~ Pub. L 93-
523
40 CFR Part 141
40 CFR 141,
SubpartF
Ooal of the Act is to protect human
health by protecting the quality of
drinking water. The Act authorizes
establishment of drinking water
standards.
Establishes primary maximum
contaminant levels (MCLs) that are
health-based standards for public
water systems.
Establishes drinking water quality
goals set at levels of no known or
anticipated adverse health effects, with
an adequate margin of safety.
60
Yes/No
Yes/No
No/Yes
Applies to CERCLA site discharges to
public drinking water sources,
including underground drinking water
sources.
MCLs are ARARs for any water that is
considered a source or potential source
of drinking water. MCLs are
applicable at the tap when water is
provided directly to 2S or more people
or 15 or more service connections.
Otherwise, MCLs are relevant and
appropriate.
MCLGs are not fedemlly enforceable
drinkingwaterstandarda,butCERCLA
t 121(d) has mised MCLGs and water
quality criteria (see below) to the level
of potentially relevant and appropriate.
. MCLGs may be considered when a
CERCLA cleanup may require more
stringent standarda than the MCLs.
-------
TABLE 7.1
APPLICABLE OR RELEVANT
AND 'APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Page 61 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Clean Water Act
Water Quality Criteria
BPA.HT3
33 U.S.C.
A 1251-1376
40 CFR Part 131
Quality Criteria
for Water, 1976,
1980, 1986
Provides for the restoration and
maintenance of the chemical, physical,
and biological integrity of the nation's.
waters. Enabling statute for a system'
of minimum national standards for
effluent discharge; . construction
grant program for POTWs; ocean
discharge requirements; and water
quality criteria.
Federal water quality criteria are
gu~delines from which states establish
their water quality standards. Criteria
are developed for the protection of
human health and aquatic life.
61
Yes/No
NolY es
EP A has established that the use of
MCLGs will be decided on a case-by-
case basis. MCLGs are relevant and
appropriate when the chemical-specific
goal is not zero.
Applicable to direct discharges to
surface waters. An indirect discharge
to a POTW may be considered an off-
site activity even if the conveyance
system is on site. A POTW may
require a CERCLA wastewater to meet
"pretreatment" standards prior to
acceptance. If a water quality standard
is available for a contaminant, that
. standard should be used rather than the.
criteria. Basin Plans established water
quality standards in the slates. Water
-------
TABLE 7.1
Page 62 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND 'OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
quality criteria are relevant and
appropriate when no standard exists.
Toxic Pollutant 40 CFR Part 129 Establishes effluent standards or NolNo Applies to specified facilities that
Effluent Standards prohibitions for certain toxic discharge into navigable waters.
pollutants: aldrin/dieldrin, DDT,
endrin, toxaphene, benzidine, PCBs.
National Pollutant 40 CFR Part 122, Requires permits for the discharge of YeslNo Substantive requirements apply to
Discharge Elimination 125 pollutants from any point source into discharges to surface water bodies or to
System waters of the United States. The Act the local storm drain system.
defines I point source as any Pretreatment standards may have to be
discemable, confined, or discrete met for discharges to the POlW.
conveyance from which pollutants are
or may be discharged. Effluent
limitations must protect beneficial uses
of water.
National Pretreatment 40 CFR Part 403 Sets standards to control pollutants Y eslNo
Standards that pass through or interfere with
treatment processes in publicly owned
treatment works (p01W) or that may
contaminate sewage sludge.
: I!.PA.K1'3
,
62
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TABLE 7.1
Page 63 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND . OPERABLE UNIT
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Clean Air Act 42 U.S.C. Regulates emissions to protect human NolY es Substantive requirements of the various
U7401~ health and tho environment. Enabling programs (e.g., NESHAPs, NSPS)
satute for major provisions such IS provided by the Clean Air Act are
National Ambient Air Quality implemented primarily through the
Standards, NESHAPs, NSPS. regional Air Pollution Control Districts
for stationary sources. Applicable to
remedial alternatives that may result in
air emissions. .
National PrimaIy and 40 CPR Part 50 Establishes National Ambient Air NolY es Primary standards applicable to any
Secondary Ambient Quality Standards (NAAQS) for the alternative emitting regulated
Air Quality Standards protection of public health and pollutants.
welfare.
National Emission 40 CPR Part 61 Sets emission standards, monitoring, No/Yes Chemicals regulated by NESPHAPs
Standards for and testing requirements for have been identified at the site, but
Hazardous Air designated hazardous pollutants such emission sources named in the
Pollutanta (NESHAPs) IS inorganic arsenic. Standards apply regulation are not components of the
only to sources specifically named in remedial alternatives under evalustion.
the regulations.
Solid Waste Disposal 42 U.S.C. If This law has been amended by RCRA
Act 6901-6987 and HSW A.
Hazardous Waste 40 CPR Part 260 ' Provides definitions of hazardous Y eslY es Defmitions may be applicable or
Management Systems waste terms, procedures for role- relevant and appropriate to various
General making petitions, and procedutes. for potential activities. May be applicable
BPA.~ 63
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TABLE 7.1
APPLICABLE OR RELEVANT
AND A PPROPRIA TE REQUIREMENTS
UPLAND'OPERABLE UNIT
Page 64 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
if variances or delisting is required.
Standards Applicable
to Generators of
Hazardous Waste
Standards for Owners
and Operators of
Hazardous Waste
Treatment, Storage,
and Disposal Facilities
(RCRA)
General Facility
Standards
Preparedness and
Prevention
Contingency Plan and
Emergency Procedures
BPA.KI1
: .
40 CFR Part 262
40 CFR Part 264
40 CFR 264.10,
~ Subpart B
40 CFR 264.30,
~ Subpart C
40 CFR 264.50,
~ Subpart D
delisting a waste.
Establishes standards for generators of
hazardous waste.
Establishes minimum national
standards that define the acceptable
management of hazardous waste for
owners and operators of facilities that
treat, store, or dispose of hazardous
waste.
64
YeslNo
YeslY es
YeslY es
YeslNo
YeslNo
Applicable if the selected alternative
involves generation and off-site
transportation of hazardous waste.
Any remedy that involves current
treatment, storage, or disposal
generally will be applicable. If the
action does not involve current
treatment, storage, or disposal, it may
, be relevant and appropriate.
Applicable to on-site treatment,
storage, or disposal of hazardous
waste. Location standarda (i.e.,
setback from a Holocene fault and
design, construction, operation, and
maintenance standards relative to the
lOO-year flood) may be applicable for a
new landfill. .
Applicable to on-site treatment,
storage, or disposal of hazardous
waste.
Applicable to on-site treatment,
storage, or disposal of hazardous
-------
TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND 'OPERABLE UNIT
Page ~S of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
waste.
Manifest System,
Record-keeping, and
Reporting
Releases from Solid
Waste Management
Units
Closure and Post-
Closure
Financial Requirements
Use and Management
of Containem
Tank Systems
BPA.HT3
40 CFR 264.70,
~ Subpart E
40.CFR 264.90,
~ Subpart F
40 CFR 264.110,
m.-.. Subpart 0
40 CFR 264.140,
~ Subpart H
40 CFR 264.170,
~ Subpart I
40 CFR 264.190,
~ Subpart J
Yes/No
Yes/No
Yes/No
Yes/No
Yes/No
No/No
65
Applicable only if waste is transported
for off-site treatment, storage, or
disposal.
Applicable if hazardous waste remains
on site. The maximum contaminant
concentrations that can be released
from haz.ardous waste units are
identical to the MCLs.
Applicable if hazardous waste is treated
or stored in . new on-site unit. Not
applicable to consolidation within area
of contamination or to in situ treatment.
Applicable for closure/post-closure of
any treatment unit.
Applicable if alternative involves
storage of hazardous waste in
containem.
Applicable if alternative involves
treatment or storage of hazardous waste
in tank system(s).
-------
TABLE 7.1
Page 66 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Applicable!
Relevant and
Statue or Regulation Citation Description Appropriate Comments
Surface Impoundments 40 CFR 264.220, No!No No alternative is being considered that
~ Subpart K would use a surface impoundment.
Waste Piles 40 CFR 264.250, YeslNo Applicable if alternative involves
~ Subpart L storage of hamrdous waste in waste
piles for more than 90 days.
Miscellaneous Units 40 CFR 264.600, YeslNo Applicable if alternative involves on-
~ Subpart X site treatment in . miscellaneous Unit.
Standards for the 40 CFR Part 266 Establishes requirements that apply to NolNo No alternative is being considered that
Management of recyclablo materials that are reclaimed would involve recycling or reusing
Specific Hazardous to recover economically significant hazardous waste.
Waste and Specific amounts of precious metals, including
Types of Hazardous gold and silver.
Waste Management
Facilities
Interim Standards for 40 CFR Part 267 Establishes minimum national No!No The selected alternative does not
Owners and Operators standards that define acceptable involve use of a new land disposal
of New Hazardous management of hazardous waste for facility; 40 CFR Part 267 standards are
Waste Land Disposal new land disposal facilities. not applicable.
Facilities
Land Disposal 40 CFR Part 268 ReStricts the land disposal of Yes!No Applicable if the selected alternative
Restrictions \ hazardous waste and specifies involves placement of waste from
treatment standards that must be met outside the area of contamination, if
before these Wastes can be land. waste is removed, treated, and
!PA.HT3
56
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TABLE 7.1
Page 67 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
disposed. redeposited into the same or another
unit. A treatability variance may also
be applicable.
Hazardous Waste 40 CFR Part 270 Establishes provisions covering basic No/No Permits are not required for on-site
Permit Program EP A permitting requirements. CERCLA response actions.
Substantivo requirements of 40 CFR
264 may be applicable.
Occupational Safety 29 U.S.C. U Regulates worker health and safety. NolY es Applies to all response activities under
and Health Act 6S 1-678 the NCP. (Superceded by CAL-
OSHA.)
Hazardous Material 49 U.S.C. If
Transportation Act 1801-1813
Hazardous Materials 49 CFR Parts Regulates transportation of hazardous YeslNo Applicable if waste is shipped off site.
Transportation 107, 171-117 materials.
Regulations
National Historic 16 U.S.C. t 470 Requires federal agencies to take into NolNo No district, site, building, structure, or
Preservation Act account the effect of any federally object will be affected that is included
40 CFR 6.301(b) assisted undertaking or licensmg on in or eligible for the National Register
any district, site, building, structure, of Historic Places.
36 CFR Part 800 or object that is included in or eligible
\ for the National Register of Historic
Places.
SPA .Im
,
67
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TABLE 7.1
Page 68 of 22
APPLICABLE OR RELEVANT
AND A PPROPRIA TE REQUIREMENTS
UPLAND. OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
Archaeological and 16 U.S.C. f 469 Establishes procedures to provide for NolNo No historical or archaeological data
Historic Preservation preservation of historical and archae- will be affected.
Act 40 CFR 6.301(c) ological data that might be destroyed
through alteration of terrain as a result
of a federal construction project or a
federally licensed activity or program. .
Historic Sites, 16 U.S.C. II Requires federal agencies to consider NolNo No naturallandmarlcs will be affected.
Buildings. Objects. and 461-467 tho existence and location of
Antiquities landmarks on the National Registry of
40 CFR 6.301(a) Natural Landmarks to avoid
undesirable impacts on such
landmarks.
Fish and Wildlife 16 U.S.C. It Requires consultation when federal YeslNo F & W Services have been notified.
Coordination Act 661-667 department or agency proposes or The full extent of this ARAR will be
authorizes any modification of any . evaluated in the FS for the Wetland
stream or other water body and Operable Unit.
requires adequate provision for
protection of fish and wildlife
resources.
Endangered Species 16 U.S.C. 1531- Requires action to conserve YeslNo The clapper rail and salt marsh harvest
Act 1536 endangered species within critical mouse are endangered species that
50 CFR Part 402 habitats upon which endangered inhabit tidal lands surrounding the site.
o species depend; includes consultation Evaluation of this ARAR will be
with Department of Interior. conducted in the FS for the Wetland
Operable Unit.
I!PA.HT3 68
I
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TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND 'OPERABLE UNIT
Page 69 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Clean Water Act
Dredge or Fill
Requirements (Section
404)
Protection of
Navigable Waters and
of Harbor and River
Improvements
Generally
General Regulatory
Policies - Department
of the Army Corps of
Engineers
Executive Order,
Protection of Wetlands
BPA.HT3
33 U.S.C. It
1251-1376
40 CFR Parts
230, 231
33 U.S.C. f 403
33 CFR Parts
320-330
Exec. Order
11990
40 CFR 16.302(a)
and Appendix A
Requires permits for discharge of
dredged or fiU material into navigable
waters.
Requires permit for structures or work
in or affecting navigable waters.
Requires federal agencies to avoid, to
the extent possible, the adverso
impacts associated with the destruction
or loss of wetlands and to avoid
support of new construction in
wetlands if a practical alternative
I exists.
69
No/No
NolNo
No/No
There may be discharge of dredged or
fill materials into navigable waters as
part of remediation of the Wetland
Operable Unit.
No activities in this operable unit will
discharge dredged or fill materials into
, navigable waters of the U.S.
This will be evaluated in the FS for the
Wetland Operable Unit.
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,~
TABLE 7.1
Page 70 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
Executive Order, Exec. Order Requires federal agencies to evaluate YeslNo Zone was defined as a loo-yesr
Floodplain 11988 the potential effects of actions they shallow flooding area. The loo-year
Management may take in a floodplain to avoid flood is not expected to affect the site
adverse impacts associated with diret under post-project conditions.
and indirect development of a
floodplain.
National Wilderness 16 U.S.C. f 1131 Establishes the national system of NolNo There are no wilderness areas on or
Preservation System SO CPR f 35.1 wilderness areas, including a policy adjacent to the site.
for protecting and managing these
areas. It prohibits certain activities
within wilderness areas.
National Wildlife 16 U.~.C. f Restricts activities within a National NolNo There are no wildlife refuge areas on
Refuge System 668dd Wildlife Refuge. or adjacent to the site.
Administration Act SO CPR f 27
Wild and Scenic 16 U.S.C. f 1271 Prdhibits adverse effects on scenic NolNo There are no designated wild or scenic
Rivers Act 40 CFR f rivers. rivers on or adjacent to the site.
'" 6.302(0)
State Reouirements. Criteria. or Limitations
Coastal Zone 16 U.S.C. f 1451 Governs activities in the coastal zone. NolNo No activities in this operable unit will
Management Act occur within the coastal zone.
!FA.1m
70
I
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TABLE 7.1
Page 91 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
Air Resources Act Health & Safety Regulates both non-vehicular and YeslNo The Act is implemented primarily
Code, Div. 26, vehicular soun:es of air contaminants through the APCDs for stationary
Sec. 39000~ in California. Defines relationship of sources.
the California Air Resources Board
l1CCR, Part III, (ARB) and local or regional air
Chapter I, Sec. pollution control districts (APCDs).
6000 ~ Establishes Ambient Air Quality
Standards.
Bay Area Management Pollution Control Rules and regulations pertain to YeslNo Substantive requirements applicable to
Pollution Control District Rules and stationary sources of air emissions. alternatives that have the potential to
District Rules and Regulations Rules address prohibition of visible emit air pollutants.
Regulations emissions; incinemtor standards;
nuisance, and compliance with PSD,
NESHAPs, NSPS, and ambient air
emission standards.
Air Toxics -Hot Health & Safety Requires opemtors of facilities . YeslNo Substantive requirements are not
Spots- Information and. Code, Chapter emitting more than a specified level of applicable to activities considered in the
Assessment Act 1252 Stats 1981 pollutants to perform an assessment of proposed alternarives.
Sec. 44300 ~ those emissions. Certain facilities, as
prioritized by the air district, will need
to perform a risk assessment.
BrA .1lI'3
71
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TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND OPERABLE UNIT
Page 72 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
California Safe
Drinking Water Act
Porter Cologne Water
Quality Control Act
: EPA.1m
.
Health &. Safety
Code, Div. S,
Part I, Chapter 7,
Sec. 4010 ~
22 CCR, Div. 4,
Chapter IS, Sec.
64401 ~
Water Code, Div.
7, Sec. 13000 ~
HQ,.
Regulations governing public water
systems; provides for drinking water
quality standards - Maximum
Contaminant Levels (MCLs) and
Secondary Maximum Contaminant
Levels (SMCLs).
Establishes primary and secondary
drinking water standards for public
water systems.
Identifies general duties and
authorities of state and regional water
boards, including preparation of .
Basin Plan and enforcement of water
quality regulations.
172
NolY es
YeslNo
MCLs are acceptable concentration
limits from a -free flowing cold water
outlet of the ultimate user. - To apply
this standard as a cleanup level for
groundwater means that the law, and
the standard, is -relevant and
appropriate. -
The San Francisco Bay Regional Water
Quality Control Board will be involved
in setting cleanup goals for contami- .
nated soil and groundwater and for
establishing acceptable conditions for
reinjection. The Region 2 Basin Plan
includes limitations on surface water
discharges. It adopts State Board
Resolutions 68-16, which applies to
maintaining water quality: 88-63,
which sets criteria for groundwater to
be considered a drinking water source;
and Regional Board Resolution 88-160,
which applies to disposal of extracted
groundwater from groundwater remedi-
ation projects. RWQCB Order No. 91-
016 requires that remediation plans be
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TABLE 7.1
Page 73 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND . OPERABLE UNIT
Statue or Regulation
Citation
Description
Applicable/
Relevant and
Appropriate
Comments
developed for the site.
23 CCR. Div. 3:
- Chapter 9, Sec. Waste Discharge Reports and YeslY es Substantive requirements may apply.
2200 ~ Requirements.
- Chapter 9.1, Enforcement Procedures for Cease No/No These are administrative requirements.
Sec. 2240 a and Desist Orders. not ARARs.
m..
- Chapter 10, Sec. Licensing and Regulation of Use of NolNo Oil spill cleanup agents are not part of
2300 ~ Oil Spill Cleanup Agents potential aI~tives.
- Chapter IS, Sec. Discharge of Waste to Land. Y cslY es Substantive requirements may be
251O~ Regulations establishing waste and site applicable or relevant and appropriate
classifications and waste management if alternative involves use of new
requirements for waste treatment,. landfill. No alternatives involve the
~torage, or disposal in landfills, use of new landfills.
surface impoundments, waste piles,
and land treatment facilities.
- Chapter 16, Sec. Underground Tank Regulations. New NolNo There are no underground tanks to be
2610 ~ and existing UST construction, remediated.
monitoring, repairs, releases of
, substances, and closure.
BPA.HT3
73
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TABLE 7.1
Page 74 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND.OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
Water Well Standards, Bulletin 74-81 The standards are intended to apply to YeslNo Well construction, abandonment, and
State of California the construction and major destruction will comply with these
reconstruction or destruction of water standards.
wells.
California Hazardous Health & Safety Regulations governing hazardous Y eslY es
Waste Control Laws Code, Div. 20, waste control; management and
Chapter 65, Sec. control of hazardous waste facilities;
25100, ~ transportation; laboratories;
classification of extremely hazardous,
hazardous, and nonhaurdous waste.
22 CCR, Div. 4 Minimum standards for management YeslY es
Chapter 30, of hazardous and extremely hazardous
Sec. 66001 ~ waste.
Safe Drinking Water & Health & Safety Provides protection of drinking water NolNo Provisions apply only to certain listed
Toxics Enforcement Code, Div. 20, by prohibiting any detectable chemicals and to persons in the course
Act of 1986 Chapter 6.6, Sec. discharge of certain listed carcinogens of doing business. Additionally, the
(WProposition 65W) 26249.5 ~ and reproductive toxicants. Requires treated water is returned to the same
warnings to be given when any source or water supply.
exposure to the chemicals (regulated
under the Act) is anticipated.
iI!PA.HT3
I
74
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'10;
.
TABLE 7.1
Page 7S of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND 'OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
California Hazardous Health & Safety Establishes a program to provide for Y eslNo
Substanco Account Code, Div. 20, response authority for releases of
ActlHazardous Chapter 6.8, Sec. hazardous substances; compensation
Substances Cleanup 25300 ~ for injuries resulting from exposure to
Bond Act release of hazardous substances; and
adequste matching funds for CERCLA.
actions.
Hazardous Materials Health & Safety Reporting requirements for. release NolNo Not an ARAR for CERCLA activities.
Release Plans and Code, Div. 20, or threatened rel~ of. hazardous
Inventory Chapter 6.95, material. Sets requirements for W Area
Requirements Sec. 25500 ~ Plansw; wBusiness Plansw; the Acutely
Hazardous Materials Registration
19 CCR, Chapter form; and the Risk Management and
2, Subchapter 3, Prevention Program.
Sec. 2620 ~
Environmental Quality Health & Safety Requirements and procedures for NolNo Not an ARAR for CERCLA activities.
Assessment Code, Div. 20, preparation of environmental quality
Requirements Chapter 6.98, assessments (environmental audits).
Sec. 25570 ~
Hazardous Substances Health & Safety Provides defmitions of whazardous Yes/No Applicable to hazardous substances
Act Code, Div. 22, substancoW and Wtoxic.. identified in the code.
Chapter 13. Sec.
28740 ~
EPA.1fI1
.
75
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TABLE 7.1
Page 76 of 22
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND -OPERABLE UNIT
Applicablel
Relevant and
Statue or Regulation Citation Description Appropriate Comments
CaliforiUa Pub.Res. Code, Provides for the environmental review NolNo Substantive requirements will be met
Environmental Quality Div. 13 of discretionary actions. via the Ecological Assessment being
Act (CEQA) conducted for the Wetland Operable
Unit.
14 CCR, Div. 6, Guidelines for implementation of The RWQCB is categorically exempt
Sec. 15000 ~ CEQA, including responsibilities of from preparing EIRs for remediation
public agencies, lead agencies, initial projects.
studies, negative declaration
declaration process, EIR process, time
limits, contents, review, and approval.
Fish and Game Fish and Game Codifies the prohibition of water NolNo Not an ARAR for the upland FS. Will
Regulations on Code, Div. 6, pollution with any substance or be an ARAR for the wetland operable'
Pollution Part I, Chapter 2, material deleterious to fish, plant life, unit.
Sec. 5650 ~ or bird life.
California Highway Cat. Vehicle YeslNo May be applicable to transportation of
Patrol Hazardous Code t 32000 ~ hazardous materials from the site.
Material ~; 13 CCR f
1160 m ~
Hazardous Waste An agreement An agreement between the NolNo If selected alternative involves off-site
Movement Committee made on Departments of Health Services, transport of large quantities of
Memorandum of November 8, Transportation (Caltrans), and hazardous waste, may have to be
Understanding 1983, by the ' California Highway Patrol to complied with. Not an ARAR because
DHS, Caltrans, coordinate with each other for the it applies to off-site activities.
and CHP transportation of targe quantities of
I BPA.'.fT3 76
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TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND . OPERABLE UNIT
Page ~7 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
California
Occupational Health
and Safety Act
Criteria for
Identification of
Hazardous and
Extremely Hazardous
Wastcs Threshold
Limit Concentrations
BPA.1IT3
Labor Code. Div.
5. Sec. 6300 m
~
8 CCR. Chapter
4: Subchapter 4.
Sec. 1500 ~
Subchapter S.
Sec. 2300 ~
Subchapter 7.
Sec. 3200 ~
22 CCR. Div. 4.
Chapter 30. Art.
11. Sec. 66693-
66747
hazardous wastes excavated from
abandoned sites.
Regulations to assure safe and healthy
working conditions by authorizing the
enforcement of standards and
procedures.
A detailed analysis of construction
safety regulations.
A detailed analysis of electrical safety
regulations.
A detailed anslysis of general
industrial safety regulations. including
procedures. equipment. and structures.
Promulgated criteria to evaluate
whether a material is hazardous.
Includea Soluble Threshold Limit
Concentration (STLC) and Total
\ Threshold Limit Concentration
(TILe).
77
Yes/No
Yes/No
Worker health and safety is regulated
primarily by CAl-OSHA. which
generally supercedes federal OSHA.
STCL and TILC chemical-speeific
values reflect the chemical
characteristics of persistence and
bioaccumulation. The limits are not
health-based.
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r
I
TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND'OPERABLE UNIT
Page 78 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Water Quality
Objectives
Underground Storage
of Hazardous
Substances
Requirements
California Coastal Act
of 1976
McAteer-Petris Act of
1969 (BCD C)
RWQCB Criteria
Health & Safety
Code, Div. 20,
Chapter 6.7, Sec.
25280 ~
Pub. Res. Code,
Div. 20, Sec.
30000 ~
Title 14
Administrative
Code, Sec. 66600
~
Promulgated criteria setting chemical-
specific concentration levels for a
variety of uses of specific bodies of
water. Based on the beneficial uses of
specified water bodies.
Regulations governing the testing,
monitoring, and replacing of
underground storage tanks.
Governs activities in the coastal zone.
Provides permit authority over any
constlUCtion within 100 feet of tidal
waters of San Francisco Bay and in
tidal waters.
Federal and State Criteria. Advisories. and Guidance to be considered
National Secondary 40 CFR Part 143 Secondary maximum contaminant
Drinking Water levels (SMCLs). Standard to control
Standards chemicals in drinking water that
\ primarily affects the aesthetic qualities
relating to public acceptance of
drinking water. .
EPA.1m
78
YeslNo
NolNo
NolNo
NolNo
Regionsl Water Quality Control
Objectives are identified in the Water
Quality Control Plan Reports (Basin
Plans) of the nine Regional Water
Quality Control Boards. May be
applicable if groundwater is reinjected.
No underground tanks will be
remediated or installed.
No activities will be performed in the
coastal zone in this operable unit.
Does not apply to the upland operable
unit. Will be an ARAR for the
wetland operable unit.
Secondary standards are not federally
enforceable; intended as guidelines for
the states. SMCLs are not ARARs
unless promulgated by state.
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TABLE 7.1
APPLICABLE OR RELEVANT
AND A PPROPRIA TE REQUIREMENTS
UPLAND. OPERABLE UNIT
Page 79 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
National Secondary
Drinking Water
Standards
National Maximum
Contaminant Level
Goals
Water Quality
Standards
BPA.HTI
40 CFR Part 143
Pub. L. 99-339,
100 Stat. 642
(1986)
40 CFR Part 131
Secondary maximum contaminant
levels (SMCLs). Standard to control
chemicals in drinking water that
primarily affects the aesthetic qualities
relating to public acceptance of
drinking water.
Establishes drinking water quality .
goals (MCWs), at levels of no known .
or anticipated adverse health effects
with an adequate margin of safety.
MCLOs do not take cost or feasibility
into account. Under SDWA, MCLOs
are Boals, Dot enforceable standards.
Nonenforceable criteria for water
quality to protect human health and
aquatic life. From the water quality
criteria, states adopt water quality
standards that protect a designated
use. A water quality standard defines
the water quality goals of a water
body through use of designations and
criteria to protect the designated uses.
79
Secondary standards are not federally
enforceable; intended as guidelines for
the states. SMCLs are not ARARs
unless promulgated by state.
CERCLA requires that the remedy
selected must require a level or
standard of control that at least attains
water quality criteria established under
Section 304 or 303 of the Clean Water
Act. CERCLA also states -in
determining whether or not any water
quality criteria...is relevant and .
appropriate. .. the President shall
consider the designated or potential use
of the surface or ground water, the
environmental media affected. the
purposes for which the criteria were
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;.::
TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND. OPERABLE UNIT
Page 80 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriate
Comments
Media Cleanup
Standards (MCSs)
(proposed)
55 FR 30798 Sec.
264.525
Proposed amendment to RCRA
regulations. MCSs are established at
concentrations that ensure protection.
of human health and the environment.
Standards are set for each medium
during the remedy selection process.
Other Potential Federal and State Criteria. Advisories. and Guidance to be Considered
Health Advisories
Corrective Action for
Solid Waste
Management at
Hamrdous Waste
Management Facilities
BPA.HT3
EP A and National
Academy of
Sciences
40 CFR 264.500 -
264.560, Subpart
S (proposed)
Health advisories developed for short-
term, long-term, and lifetime
exposures. The advisories are
considered to be guidance and are not
enforceable.
Proposed rule establishes procedures
and technical requirements for
implementing corrective action under
Section 3004(u) of RCRA. ~e
regulations define requirements for
conducting remedial investigations,
evaluating potential remedies, and
, selecting and implementing remedies
at RCRA facilities.
80
developed, and the latest information
available. .
The regulations are proposed and
therefore TOCs. When promulgated,
the standards are potential ARARs.
Provisions of the proposed rule (e.g.,
media cleanup standards, conditional
remedies) must be addressed as TOCs.
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TABLE 7.1
APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS
UPLAND. OPERABLE UNIT
Page 81 of 22
Statue or Regulation
Citation
Description
Applicablel
Relevant and
Appropriato
Comments
Site-Specific Health-
Based Goals
BPA.Kf3
--.: '~"""" . .'.."..~' . 'I .
(PRC. 1991)
Conservative concentration goals for
carcinogens and non-carcinogens in
soil.
81
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8.0
DESCRIPTION OF ALTERNATIVES
Rhone Poulenc submitted a final Remedial Investigation
Report dated September 19, 1989, draft Feasibility Studies dated
August 1989, July 30, 1991 and a final- FS report dated November
1, 1991. The reports contain the results of the subsurface in-
vestigation, a description of the groundwater and soil contamina-
tion, and an evaluation of the interim cleanup actions, and
remedial alternatives. EPA and the Regional Board staff deter-
mined that the technical information contained in the RIfFS was
acceptable for developing a final cleanup plan.
EPA and the Regional Water Quality Control Board evaluated
remedial action alternatives for the Rhone poulenc site in accor-
dance with CERCLA section 121, the National contingency Plan
("NCP"), and the Interim Guidance on Sucerfund Selection of
Remedy, December 24, 1986 (Oswer Directive No. 9355.0-19).
The Feasibility Study initially screened approximately 34
soil and 45 groundwater remedial action technologies. These
technologies were screened based on implementability, effective-
ness, and cost criteria. The remedial technologies that survived
the screening were assembled into the group of alternatives
listed below.
:.t
Remedial Alternative A
For this alternative, no action (other than groundwater
monitoring) would be performed on the Sandoz and surrounding
properties in the upland operable unit.
The components of Alternative A are listed below.
1.
Remedial Alternative A is a IIno further action" alter-
native, retained for base-line comparison purposes in
accordance with CERCLA/SARA guidance. Except for
groundwater monitoring remedial technologies are not
implemented at the site under this alternative.
Total present worth cost = $900,000
Remedial Alternative B
This alternative was developed to prevent exposure to af-
fected soil and contain contaminanted groundwater. The alterna-
tive includes paving, future soil excavation, deed restrictions,
and groundwater monitoring with future groundwater contingency
plans outlined. Each property in .the'upland operable unit, ex-
cept for Sandoz and Bains, would be remediated by either (1) ex-
cavating soil having arsenic concentrations greater than 70
mg/kg, or (2) paving areas where soil arsenic concentrations
82
-------
exceed 70 mg/kg and obtaining deed restrictions. The unpaved
portions of the Sandoz property and the Bains property containing
arsenic concentrations greater than 70 mg/kg would be paved, and
deed restrictions would be applied to both properties.
The total mass of arsenic affected by site activities is
74,800 kg ang the total volume of soils affected (> 20 mg/k~ As)
is 91,000 yd. The early action excavation removed 2260 yd of
soil and 20,000 kg of arsenic. The additional excavation that
wo~ld occur after the facility ceases operation would remove 1260
yd of soil and 10,000 kg of arsenic. Alternative B does not in-
clude treatment of contaminated soil. The volume of soil that
would be removed in Alternative B is 4% of the contaminated soil
in the upland operable unit and 40% of the mass of arsenic once
the future removal occurs. Under this alternative approximately
86% of the contaminated soil or 44,800 kg of As would be. left on
site. The slurry wall would contain 43,200 kg of As within its
boundaries.
Remedial Alternative B consists of the following:
4.
1.
Surface Cap and Deed Restrictions for Sandoz and Bains
properties.
2.
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (accessible areas occured
during September 1991). Soil having high arsenic con-
centrations in the operating portions of the Sandoz
plant and beneath structures on the Sandoz and Bains
properties would be removed when the facility ceases
operation and structures are demolished. It is uncer-
tain when remediation would be performed beneath these
areas..
3.
Removal of soils having concentrations above health-
based levels or pave affected areas having soil con-
centrations above health-based levels (> 70 mg/ks As)
on all properties except for Sandoz and Bains.. Deed
restrictions will be obtained for properties where
paving is selected..
Groundwater Monitoring of perimeter wells with a con-
tingency plan for plume containment should further
migration occur. The contingency plan allows for
groundwater extraction and treatment if statistically
significant evidence shows that anyone of the
perimeter wells exceeds 40 ppb of arsenic, or that the
arsenic concentration in the deep aquifer exceeds back-
ground levels.
5.
Installation of Slurry wall with dewatering. The in-
stallation of the slurry wall would only occur if
statistically significant evidence shows that anyone
of the perimeter wells exceeds 40 ppb of arsenic, or
83
-------
1-
that the arsenic concentration in the deep aquifer ex-
ceeds background levels. The slurry wall would sur-
round the area containing contaminated soil and ground
water remaining a~ter soil remediation. It would
enclose 76,800 yd of soil (84% of the contaminated
soil in the upland operable unit) and 43,200 kg. of ar-
senic (58% of the arsenic). Groundwater extraction
and treatment within the slurry wall is necessary to
maintain the inward hydraulic gradient across the
slurry wall. In order to estimate pumping rates and
volumes, calculations were based on a 30 year project
life. Therefore, if the dewatering system operated at
a pumpino/ rate of 2 gpm for 30 years it would remove
3.2 x 10 gallons of water.
6.
Installation of three additional deep aquifer monitor-
ing wells as outlined in the "Deep Aquifer Monitoring
Plan".
Total present worth cost = $5,800,000
Remedial Alternative C
~
This alternative is the same as Alternative B, except that a
groundwater extraction and treatment system, instead of a slurry
wall, would be installed to contain contaminated groundwater in
the shallow groundwater zone. This extraction system would only
be installed if statistically significant evidence shows that any
one of the perimeter wells exceeds 40 ppb of arsenic, or if the
arsenic concentration in the deep aquifer exceeds background
levels. Using 30 years as an estimate, the pumping rate of the
extraction syst~m would be 25 gallons per minute, and would
remove 3.9 x 10 gallons of water during this time period. The
total volume of sludge that would be generated during this 30
year timeframe would be 23,000 tons. Extracted groundwater would
be treated and discharged to the local storm drain under an NPDES
permit.
The volume of soil that would be removed in Alternative C is
4% of the contaminated soil in the upland operable unit and 40%
of the mass of arsenic once the future removal occurs. Under
this alternative approximately 98% of the contaminated soil and
60% of the mass of As would be left on site.
Remedial Alternative C consists of the following:
1.
Deed restrictions for Sandoz and Bains properties
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (accessible areas occured
during September 1991). Soil having high arsenic con-
centrations in the operating portions of the Sandoz
plant and beneath structures on the Sandoz and Bains
properties would be removed when the facility ceases
2.
84
-------
operation and structures are demolished. It is uncer-
tain when remediation would be performed beneath these
areas.
3.
Removal of soils having concentrations above health-
based levels or pave affected areas having soil con-
centrations above health-based levels (> 70 mg/kg As)
on all properties except for Sandoz and Bains. Deed
restrictions will be obtained for properties where
paving is selected. .
4.
Groundwater Monitoring of perimeter wells with a con-
tingency plan for plume containment should further
migration occur. The contingency plan allows for
groundwater extraction and treatment if statistically
significant evidence shows that anyone of the
perimeter wells exceeds 40 ppb of arsenic, or that the
arsenic concentration in the deep aquifer exceeds back-
ground levels.
5.
Extraction and treatment of contaminated groundwater.
Extraction and treatment of contaminated groundwater in
the shallow zone will commence should the arsenic con-
centrations in the perimeter monitoring wells approach
the MCL of 50 ppb.. A precipitationl microfiltration
process was identifed as the best available method for
treating extracted groundwater. Bench-scale study
results indicate that arsenic concentrations could be
reduced sufficiently to permit water reuse, reinjec-
tion, discharge to the public sewer system or discharge
to the storm sewer. This contingency plan for
groundwater can best be described as follows:
a.
If concentrations in any perimeter monitoring
well exceed 30 ppb, the sampling frequency
will increase from annually to semi-annually.
A concentration of 40 ppb is designated as
the "trigger" level for implementing a
mitigation response for the perimeter
monitoring wells. The Aquifer Characteriza-
tion and contingency Plan describes correc-
tive action measures in detail.
6.
Installation of three additional deep aquifer monitor-
ing wells as outlined in the "Deep Aquifer Monitoring
Plan" .
Total present worth cost = $6,200,000
85
-------
Remedial Alternative D
Alternative D is the same as Alternative B except that it in-
cludes an innovative technology, treating' arsenic soil via sili-
cate fixation. . Treatability studies have been performed con-
taminated soils and the resullts are documented in the "Early Ac-
tion Removal Report". This alternative would treat soils con-
taining arsenic concentrations greater than 1000 mg/kg, which
corresponds to approximately 28,700 kg of arsenic and 11,000 yd3
of conta,inated soil. The upland unit contains approximately
6,600 yd of contaminated soil with concentrations greater than
1000 mg/kg beneath structures on the Bains and Sandoz properties.
This soil would be semoved and treated at a future date. Ap-
proximately 4400 yd of soil within the Upland Operable unit
would be treated within the year. Under this remedy 38% of the
total mass of the arsenic would be eventually treated(41% of
28,700 kg As within a year, and 58% of 28,700 kg As in the
future). As in alternative B the slurry wall would contain
43,200 kg of As or 84% of contaminated soil by volume.
Remedial Alternative D consists of the following:
:.t
1.
Surface Cap and Deed Restrictions for Sandoz and Bains
properties
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (removal in accessible areas
occured during september 1991). Soil having high ar-
senic concentrations in the operating portions of the
Sandoz plant and beneath structures on the Sandoz and
Bains properties would be removed when the facility
ceases operation and structures are demolished. It is
uncertain when remediation would be performed beneath
these areas.
2.
3.
Removal of soils having concentrations above health-
based levels or' pave affected areas having soil con-
centrations above health-based levels (> 70 mg/ks As)
on all properties except for Sandoz and Bains. Deed
restrictions will be obtained for properties where'
paving is selected.
4.
Treatment of soils containing arsenic concentrations
greater than 1000 mg/kg As via silicate stabilization
method (accessible areas to occur within next year and
soils beneath buildings in the future when buildings
removed) .
5.
Groundwater Monitoring of perimeter wells with a con-
tingency plan for plume containment should further
migration occur. The contingency plan allows for
groundwater extraction and treatment if statistically
significant evidence shows that anyone of the
86
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perimeter wells exceeds 40 ppb of arsenic, or that the
arsenic concentration in the deep aquifer exceeds back-
groun~ levels.
6.
Installation of Slurry wall with dewatering. The in-
stallation of the slurry wall would only occur if
statistically significant evidence shows that anyone
of the perimeter wells exceeds 40 ppb of arsenic, or
that the arsenic concentration in the deep aquifer ex-
ceeds background levels. The slurry wall would sur-
round the area containing contaminated soil and ground
water remaining a5ter soil remediation. It would
enclose 76,800 yd of soil (84% of the contaminated
soil in the upland operable unit) and 43,200 kg of ar-
senic (58% of the arsenic). Groundwater extraction
and treatment within the slurry wall is necessary to
maintain the inward hydraulic gradient across the
slurry wall. In order to estimate pumping rates and
volumes, calculations were based on a 30 year project
life. Therefore, .if the dewatering system operated at
a pumpin~ rate of 2 gpm for 30 years it would remove
3.2 x 10 gallons of water.
7.
Installation of three additional deep aquifer monitor-
ing wells as outlined in the "Deep AquIfer Monitoring
Plan".
Total present worth cost = $7,800,000
Remedial Alternative E
Alternative E is the same as Alternative D, except it in-
cludes an innovative technology, treating arsenic soil via sili-
cate fixation and installation of a slurry wall after the Wetland
ROD is signed. This alternative would treat soils containing ar-
senic concentrations between 500 and 5000 mg/kg of arsenic. This
corresponds to 20,000 yd3 of contaminated soil which contains ap-
proximately 37,600 kg of arsenic. The upland unit contains ap-
proximately 12,200 yd3 of contaminated soil with concentrations
greater than 500 mg/kg beneath structures on the Bains and Sandoz
properties. This soil would b~ removed and treated at a future
date. Approximately, 7,600 yd of contaminated soil within the
Upland Operable unit would be treated within the year. Under
this remedy 50% of the total mass of the arsenic would be even-
tually treated(40% of 37,600 kg As within a year, and 60% of
37,600 kg As in the future). The combined initial and future
phases of fixation will result in the treatment of 22% of the
contaminated soil. As in alternative B the slurry wall would
contain 43,200 kg of As or 84% of contaminated soil by.volume.
87
-------
:.t
~
Remedial Alternative E consists of the following:
L
Surface Cap and Deed Restrictions for Sandoz and Bains
properties
2.
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (asessible areas occured during
September 91). Soil having high arsenic concentrations
in the operating portions of the Sandoz plant and
beneath structures on the Sandoz and Bains properties
would be removed. when the facility ceases operation and
structures are demolished. It is uncertain when
remediation would be performed beneath these areas.
3.
Removal of soils having concentrations above health-
based levels or pave affected areas having soil con-
centrations above health-based levels (> 70 mg/ks As)
on all properties except for. Sandoz and Bains. Deed
restrictions will be obtained for properties where
paving is selected.
4.
Treatment of soils containing arsenic concentrations
greater than 500 mg/kg As via silicate stabilization
method (accessible areas to occur within next year and
soils beneath buildings in the future when buildings
removed) .
5.
Groundwater Monitoring of perimeter wells with a con-
tingency plan for plume containment should further
migration occur. The contingency plan allows for
groundwater extraction and treatment if statistically
significant evidence shows that anyone of the
perimeter wells exceeds 40 ppb of arsenic, or that the
arsenic concentration in the deep aquifer exceeds back-
ground levels.
6.
Installation of Slurry wall with dewatering. The
slurry wall would surround the area containing con-
taminated soil and ground water remainin~ after soil
remediation. It would enclose .76,800 yd of soil (84%
of the contaminated soil in the upland operable unit)
and 43,200 kg. of arsenic (58% of the arsenic).
Groundwater extraction and treatment within the slurry
wall is necessary to maintain the inward hydraulic
gradient across the slurry wall. In order to estimate
pumping rates and volumes, calculations were based on a
30 year project life. Therefore, if the dewatering
system opera~ed at a pum~ing rate of 2 gpm for 30 years
it would remove 3.2 x 10 gallons of water and generate
1900 tons of sludge. .
88
-------
7.
Installation three additional deep aquifer monitoring
wells. The goal would be to have a minimum of three
well pairs that would monitor the upper shallow zone,
the lower shallow zone, and the deep aquifer zone.
8.
Installation of a cap and liner.
Total present worth cost = $9,100,000
Remedial Alternative F
Alternative F is the same as Alternative E except that it sub-
stitutes groundwater extraction and treatment in place of the
slurry wall installation. The volume of soil and mass of arsenic
impacted would be exactly the same as those numbers denoted in
Alternative E. Using 30 years as an estimated project life, the
system would operate at a pumping rate of 25 gpm, remove 3.9 x
108 gallons of water, and generate 23,000 tons of sludge from the
complete removal of TDS from this water.
Remedial Alternative F consists of the following:
1.
Deed restrictions for Sandoz and Bains properties
2.
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (asessible areas occured during
September 91). Soil having high arsenic concentrations
in the operating portions of the Sandoz plant and
beneath structures on the Sandoz and Bains properties
would be removed when the facility ceases operation and
structures are demolished. It is uncertain when
remediation would be performed beneath these areas.
Removal of soils having concentrations above health-
based levels or pave affected areas having soil con-
centrations above health-based levels (> 70 mg/ks As)
on all properties except for Sandoz and Bains. Deed
restrictions will be obtained for properties where
paving is selected.
3.
4.
Treatment of soils containing arsenic concentrations
greater than 500 mg/kg As via silicate stabilization
method (accessible areas to occur withi~ next year and
soils beneath buildings in the future when buildings
removed).
5.
Groundwater Monitoring
89
-------
6.
Extraction and treatment of contaminated groundwater.
Extraction and treatment of contaminated groundwater in
the shallow zone will commence should the arsenic con-
centrations in the perimeter monitoring wells approach
the MCL of 50 ppb. A precipitation/ microfiltration
process was identifed as the best available method for
. treating extracted groundwater. Bench-scale study.
results indicate that arsenic concentrations could. be
reduced sufficiently to permit water reuse, reinjec-
tion, discharge to the public sewer system or discharge
to the storm sewer. This contingency plan for
groundwater can best be described as follows:
A.
If concentrations in any perimeter monitoring well
exceed 30 ppb, the sampling frequency will in-
crease from annually to semi-annually.
B.
A concentration of 40 ppb is designated as the
"trigger" level for implementing a mitigation
response for the perimeter monitoring wells. The
Aquifer Characterization and Contingency Plan
describes corrective action measures in detail.
7.
Installation of three additional deep aquifer monitor-
ing wells as outlined in the "Deep Aquifer Monitoring
Plan".
~t
Total present worth cost = $9,500,000
Remedial Alternative G
This alternative was developed to minimize long-term manage-
ment of the site.. Soil containing arsenic concentrations above
background, or greater than 20 mg/kg would be removed from the
Sapdoz and surrounding properties. contaminated groundwater in
the shallow zone would be removed during the excavation and
groundwater monitoring would continue to be performed. The
dewatering process would remove 50 million gallons of water -
during the excavation period and generate 3000 tons of sludge.
The early action removed 2260 yd3 of soil and 20,000 kg of
arsenic. This remedy would result in excavation of an addtional
89,580 yd3 of soil and 76,900 kg of arsenic. The proposed soil
treatment via silicate fixation would be performed in ensure that
the soil leachability values would meet land ban requirements.
Implementation of this remedy would be completed within six years
of the excavation start date. Alterna~ive G would result in the
removal of 100% of the contaminated soil and 100% of the arsenic
in the upland operable unit.
90
-------
Remedial Alternative G consists of the following:
1.
Remove all soils with arsenic concentrations greater
than 20 mg/kg. Removal of soils containing arsenic
conceritrations greater than 5000 mg/kg (accessible
areas occured during September 1991).
2.
Groundwater Monitoring
3.
Installation of three additional deep aquifer monitor-
ing wells as outlined in the "Deep Aquifer Monitoring
Plan".
Total present worth cost = $85,000,000
91
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TN3LE 8.1
FSTIMA TED COSTS OF ALTERNATIVES
UPLAND OPERABLE uNIT
1990 Bay Road Site
East Palo Alto, California
(Costs in $ millions)
Alternative
Capital Costs: A B ~ n E E !i
Design Engineering: 0 0.3 0.3 0.5 0.6 0.6 13
Construction Costs: 0 1.3. 1.3 1.9 2.3 2.3 48
Construction Contingencies: 0 0.4 0.4 0.6 0.8 0.8 17
Services During Construction: Q Q.1 Q.1 Q.J '.:.~ ~ ~
Total Capital Costs: 0 2.2 2.2 3.3 4.0 4.0 84
'j.
Present Value (PV) of Future Costs1
(5% rate of return):
PV of Operations and Maintenance
(Years 1 to 30): .0.9 1.1 1.1 1.1 1.1 1.1 1.1
PV of FutUre Remediation: Jl U U U. !al ~ Jl
Total Present Value of Future Costs: 0.9 3.6 4.0 4.6 5.2 5.6 1.1
(PVFC)
-30% 0.6 4.1 4.3 5.5 6.4 6.6 60
Net Present Value (Capital Costs
plus PVFC): 0.9 5.8 6.2 7.8 9.1 9.5 85
+50% 1.4 8.7 9.3 12 14 14 128
~~: .
1. Cost estimates assume that deferred remediation, including excavation, treatment,
paving, and groundwater containment, would be implemented in 15 years. .
2. Detailed cost data and methodology presented in Appendix E.
FEAS\cosr .TBL
92
-------
L~.
(\
Upland
Operable Unit
"'-
. - .
PG&E
"!. Substation
\ 'I.
-:-
Tidal Marsh
City of Palo Alto
Property
1
~
,
- - .--. .-
~- Levee
.. - -- ".....
KEY
- - - Proposed slurry wall location
o
I
200 Feet
I
Figure
;/)f
a 80MATR 1)(
PROPOSED SLURRY WALL LOCATION
1990 Bay Road Site
East Palo Alto. California
8.1
Project No
1220F
93
-------
:.t
-J
[--- .
.'
(:,.
Tidal Marsh
City of Palo Alto
Property
o
I
200 Feet
I
Torres Property
\ .'
\ '" ~ .
\\ ,;.<"~,y.,.
J-.,..r:-J -
~\\.> 0 .-' ."'-
\ CJ ,,'
\ \
\ \
\ \
-------~
WEEKS STREJ~I_. ----- -.u -.
-- ------ ".-
l
l
o
-.
-Levee
.-----
Currenlly unpaved areas to
be paved under Ahernallves
B through F (Includes deed
restrlc1lons on properties)
EXPLANATION
....... '" '" 'i Inacx:essable areas In
~ Upland Operable lInh
to be remediated In
the luture under
Ahemalives B through F
~
~
Currenlly unpaved areas where SOIl
with arsenic conc:envations In excess .
01 70 mgIkg wII be removed or the
deed restricted and the surface paved
under Altematives B Ih.ough F
q:;c......
a80MATRrK
PROPOSED REMEDIATION PLAN
UPLAND OPERABLE UNIT
1990 Bay Road Site
East Palo Alto. Calilornia
. Figure.
Project No
1220F
94
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9.0
COMPARATIVE ADLYSIS OP ALTE1UD\TIVES
This section provides an explanation of the criteria used to
select the remedy, and an analysis of the remedial action alter-
natives in liqht of those criteria, hiqhliqhtinq the advantaqes
and disadvantaqes of each of the alternatives.
criteria
The alternatives were evaluated usinq nine component
criteria" These criteria, which are listed below, are derived
from requirements contained in the National Continqency Plan
(NCP) and CERCLA sections 121(b) and 121(c).
The alternatives were evaluated in detail with respect to
the nine criteria in the FS report. A detailed analysis of the
alternatives was completed in the FS. A summary of this detailed
analysis is shown on Table 9.1.
2.
4.
L
Overall protection of human health and the environment.
This criterion addresses whether a remedy provides ade-
quate protection of human health and the environment.
Compliance with applicable or relevant and appropriate -
requirements (ARARs). This criterion addresses whether
a remedy will meet all of the ARARs or' other Federal
and state environmental laws.
3 '.
Lonq-term effectiveness and permanence. This criterion
refers to expected residual risk and residual chemical
concentrations after cleanup standards have been met
and the ability of a remedy to maintain reliable
protection of human health and the environment over
time. -
Reduction of toxicity, mObility or volume throuqh'
treatment. This criterion refers to the anticipated
performance of the treatment technoloqies a remedy may
employ.
5.
Short-term effectiveness. This criterion addresses the
period of time needed to achieve cleanup and any ad-
verse impacts on human health and the environment that
may be posed during the construction and implementation
period, until cleanup standards are achieved.
Implementability. This criterion refers to the techni-
cal and administrative feasibility of a remedy.
6.
7.
Cost. This criterion includes estimated capital and
operation and maintenance, usually presented in a 30
year present worth format.
95
-------
'.1
:J.
8.
Support Agency Acceptance This criterion addresses
EPA's acceptance of the selected remedy and any other
EPA comments.
9.
Community Acceptance This criterion summarizes the
public's general response to the alternatives.
Groundwater and 80il
Threshold Criteria
Overall Drotection of human health and the environment
Alternatives D, E, F and G would be protective of human
health and the environment. Alternatives A, B, and Care
not protective of human and health and the environment. The
no action alternative and institutional control remedies
would not eliminate potential exposure to contaminated soil
and groundwater that are present above health-based levels.
Alternatives Band C rely on institutional controls which
offer protection only if the integrity of the cap is main-
tained and deed restrictions remain effective. Alternatives
D, E, and F have the same components as Alternatives Band
C, but these alternatives add silicate fixation as an in-
novative treatment technology for soils above the health-
based levels. Alternative G provides protection of human
health and the environment by removing all contaminated
soils and groundwater to an off-site disposal facility.
ComDliance with aDDlicable or relevant and aDDroDriate re-
quirements
with the exception of Alternatives A, Band C all of the al-
ternatives meet ARABs. Alternatives A, B, and C would not
meet 40 cn Parts 264 and 265. Alternatives Band C would
involve removal of characteristic waste and Land Disposal
Restrictions would apply. For those alternatives that in-
volve excavation and treatment, health-based cleanup stan-
dards for soils were calculated based on TBCs ident~fied for
the site (CPFs and RfDs contained in IRIS), and have been
selected as soil cleanup standards. Alternatives D, E, and
F meet the standards through treatment and containment.
Primary Balancing criteria
Lona-term effectiveness and Dermanence
Alternative G would provide the greatest level of lonq-
term effectiveness since this alternative entails near-
complete removal of contaminated soils and groundwater.
This alternative would require almost no long-term monitor-
96
-------
ing and maintenance, but it would require treatment and dis-
posal of large volumes of soil and sludge at off-site
facilities. Alternatives D, E, and F, would provide a high
level of long-term effectiveness since they all utilize
treatment. Soil fixation and containment of contaminated
groundwater within a slurry wall would effectively treat the
bulk of site contaminated soil.
Alternatives B, and C offer a moderate level of long-term
effectiveness since they rely on continued and proper main-
tenance of the cap and institutional controls. Alternatives
A and B provide little protection against exposure to con-
taminated soils and groundwater.
Reduction of toxicitv. mobilitv. or volume throuah treatment
Reductions in toxicity, mobility, or volume of contaminants
in the upland operable unit are achieved primarily by reduc-
ing the volume of soil through removal, treatment, and dis-
posal of contaminated soil and groundwater from the site.
Reduction in mobility is handled through capping, fixation,
and groundwater containment. The mass and volume of con-
tamination removed, treated, and contained by each alterna-
tive are presented in Table 9.2. The inherent toxicity of
arsenic cannot be reduced effectively by any available
treatment technology.
The total volume of contaminated soil in the upland operable
unit is estimated to be 91,000 cubic years, which is calcu-
lated to contain about 75,000 kg of arsenic. Alternative G
would remove the entire volume of contaminated soil.
Removal of soils containing arsenic concentrations greater
than 5000 mg/kg effectively reduces the mass of arsenic in
contaminated soils by about 40% and the volume of con-
taminated soils by about 4%.
Capping and fixation would reduce mobility of contaminants.
Surface capping would also eliminate the emission of con-
taminated fugitive dust from surface soils and would reduce
leaching of contaminants by eliminating surface water in~
filtration.
Alternatives D, E, and F would result in significant reduc-
tions in the mobility and volume of contaminated soil by
binding the contaminants to the soil. Results of
treatability studies indicate TCLP standards would be met.
Soils that are characteristic wastes prior to treatment
would no longer be characteristic after treatment. Alterna-
tives E and F would treat approximately 84% of the total
mass of arsenic remaining after cpncentrations greater than
5000 mg/kg have been removed.. The mobility of contaminants
in groundwater is reduced to very low levels as a .result of
the groundwater containment and treatment systems. The
volume of contaminated groundwater would be reduced by the
97
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groundwater pumping from within the slurry wall. Alterna-
tives A, B, and C would not provide any reduction in con-
taminant toxicity, mobility, and volume because soils would
still' contain arsenic concentrations greater than the
health-based level (500 ppm).
Short-term effectiveness
Alternatives A would not pose any short-term risks, since
access to site is already restricted and this alternative
would not disturb contaminated soil. Alternatives B through
G pose some short-term risks to community and worker health
during implementation due to generation of fugitive dust;
however, these risks could be mitigated by the health and
safety plan for the site. Offsite transport. of contaminated
material could cause a threat in the event of an accident
during transport.
Implementability
".J
All alternatives are implementable. Alternatives Band C
would be easier to implement than Alternatives D, E, and F
because they do not involve soil treatment~ Alternative D
treats a smaller volume of soil than alternatives E and F.
Alternative G would remove the greatest volume of con-
taminants at the site, but would also involve the disruption
of a business and destruction of its buildings.
Cost
The.cost for the alternatives increases as the volume of
treated soil increases. Cost for groundwater extraction is
also more expensive than installation of a slurry wall. The
cost associated with Alternative A includes groundwater
monitoring and is $900,000. Costs for the other alterna-
tives are listed below, and in Table 8.1; .
Alternative B
Alternative C
Alternative D
Alternative E
Alternative F
Alternative G
$ 5,800,000
$' 6,200,000
$ 7,800,000
$ 9,100,000
$ 9,500,000
$85,000,000
Table 9.3 lists costs for the selected remedy.
98
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SUPPORT AGENCY ACCEPTANCE
The Feasibility study and the Proposed Plan Fact Sheet were
reviewed by the California Regional Water Quality Control Board
(RWQCB). The RWQCB concurs with EPA's preferred alternative.
COMMUNITY ACCEPTANCE
The Proposed Plan was presented to the community of East
Palo Alto in a fact sheet and at a public meeting. Comments
received are addressed in the Response Summary which is included
as an attachment to this ROD.
THE SELECTED REMEDY
Based on an evaluation of the alternatives, the selected
remedy for the site is Alternative E. Rhone Poulenc has es-
timated that it will take approximately 9 months to complete the
soil stabilization process at a cost of $9,100,000.
The selected remedy sha~l consist of the fOllowing actions:
3.
4.
1.
Surface Cap and Deed Restrictions for Sandoz and Bains
properties
2.
Removal of soils containing arsenic concentrations
greater than 5000 mg/kg (accessible areas occurred
during September 91). Soil having high arsenic con-
centrations in the operating portions of the Sandoz
plant and beneath structures on the Sandoz and Bains
properties shall be removed when the facility ceases
operation and structures are demolished. It is uncer-
tain when remediation would be performed beneath these
areas.
Removal of soils having concentrations above health-
based levels or pave affected areas having soil con-
centrations above health-based levels (> 70 mg/ks As)
on all properties except for Sandoz and Bains. Deed
restrictions shall be obtained for properties where
paving is selected.
Treatment of soils containing arsenic cQncentrations
greater than 500 mg/kg arsenic via silicate stabi-
lization method (accessible areas to occur within next
year and soils beneath buildings in the future when
buildings removed).
99
-------
7.
~
8.
5.
Groundwater Monitoring of perimeter wells with a con-
tingency plan for plume containment should further
migration occur. The contingency plan requires
groundwater extraction and treatment if statistically
significant evidence shows that anyone of the
perimeter wells exceeds 40 ppb of arsenic, .or that the
arsenic concentration in the deep aquifer exceeds back-
ground levels.
Installation of Slurry wall with dewatering. The
slurry wall shall surround the area containing con-
taminated soil and ground water remainin~ after soil
remediation. It would enclose 76,800 yd of soil (84%
of the contaminated soil in the upland operable unit)
and 43,200 kg of arsenic (58% of the arsenic). .
Groundwater extraction and treatment within the slurry
wall is necessary to maintain the inward hydraulic
gradient across the slurry wall. In order to estimate
pumping rates and volumes, calculations were based on a
30 year project life. Therefore, if the dewatering
system operated at a pum~ing rate of 2 gpm for 30 years
it would remove 3.2 x 10 gallons of water and generate
1900 tons of sludge.
6.
Installation of three additional deep aquifer monitor-
ing wells. A minimum of three well pairs that would
monitor the upper shallow zone, the lower shallow zone,
and the deep aquifer zone are required.
Installation of a cap and liner.
Total present worth cost = $9,100,000
Remedy Selection Rationale and statutory Determinations
Threats to human health and the environment posed by the
Upland Operable unit, include ingestion of contaminated
groundwater, contact with contaminated groundwater, as well as
ingestion and inhalation of metals in contaminated soils. The
selected remedy for groundwater addresses the threat of exposure
. by requiring extraction and treatment of contaminated groundwater
to regulatory and or background levels. should significant
horizontal and/or vertical migration occur. The implementation
of institutional controls will provide further protection by
preventing residential use of the site.
Health-based cleanup levels for sqils were calculated based
on TBCs for the site, and have been selected as soil cleanup
standards. Under the selected remedy for soil, treated soils
will only be returned to the ground once they have been.stabi-
lized (silicate fixation technology) and meet the performance
criteria. For example, they are no longer considered a charac-
100
-------
teristic waste under TCLP testing. The selected remedy does not
involve placement of a restricted waste. EPA has determined that
Land Disposal Restrictions do not apply. The selected remedy for
soil will involve excavation of a characteristic waste. However,
prior to placement, this waste will be treated to levels that do
. not constitute a characteristic waste, and as a result LDRs will
not apply.
The selected remedy addresses the threat of exposure to con-
taminated soil in several ways. First of all, capping the site
and implementing institutional controls removes the threat caused
by ingestion and contact with contaminated soils. The selecied
rem~dY will attain acceptable carcinogenic risks levels (10- to
10- ) by eliminating the soil exposure pathway. Treatment of
contaminated soils to health-based levels also provides long-term
protection from ingestion and inhalation should capping and in-
stitutional controls become ineffective at some point in the fu-
ture. The selected remedy will provide long-term protection
within the acceptable risk range since the loil cleanup standards
will achieve a carcinogenic risk of 2 x 10- and a noncar-
cinogenic Hazard Index of less than one. Implementation of in-
stitutional controls, installing a cap and slurry wall, and per-
forming groundwater monitoring (along with extraction and treat-
ment if necessary) will ensure that the threat of exposure to the
deep drinking water aquifer is addressed.
The selected remedy also addresses the threat of exposure to
contaminated groundwater in several ways. The selected remedy is
effective in the short-term because further plume migration is
controlled by installation of the slurry wall. The slurry wall
will also require pumping and treating of groundwater to maintain
an inward hydraulic gradient. The groundwater extraction and
treatment associated with the slurry wall is a permanent solution
and significantly reduces pollutant toxicity, mobility and volume
in site groundwater. The selected remedy is effective in the
long-term by virtue of the fact that ARARs must be met in the
deep aquifer, and if contamination in the upper aquifer exceed
the 50 ppb in the perimeter wells pumping and treating of
groundwater shall commence.
101
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TABLE 9.1
DOCUMENTATION OF ARARs FOR ALTERNATIVES
UPLAND OPERABLE UNIT
RHONE POULENC/SANDOZ Site
East Pal
-------
TABLE 9.1
DOCUMENTATION OF ARARs FOR ALTERNATIVES
UPLAND OPERABLE UNIT
Page 103 of 3
Statue or Regulation Alternative A Alternatives B & C Alternatives D, E,& F Alternative G
Standards for Owners and Not applicable. No hazardous Excavated soil and groundwater Excavated soil and groundwater Excavated soil and groundwater
Operators of Hazardous Waste waste treated, stored, or disposed treatment residues will be treated treatment residues will be treated treatment residues will be treated
Treatment, Storage, and Disposal in this altetnative. and disposed as required by and disposed as required by and disposed as required by
Facilities (RCRA), including federal regulations. federal regulations. No permit to federal regulations.
General Facility Standards: perform soil treatment will be
Contingency Plan and Emergency required. The substantive
Procedures: Manifest System: requirements of a permit will be
Releases from Solid Waste satisfied by information in the
Management Units: Closure and Remedial Design Report.
Post-Closure Requirements:
Financial Requirements: Use and
Management of Containers, Tank
. Systems, Surface Impoundments,
Waste Piles, and Miscellaneous
Units; and Land Disposal
Restrictions.
Federal and State Occupational Site activities will be conducted Site activities will be conducted Site activities will be conducted Site activities will be conducted
Safety and Health Acts in accordance with these acts. in accordance with these acts. in accordance with these acts. in accordance with these acts.
Hazardous Material Not applicable. No soil is Hazardous materials will be Hazardous materials will be Hazardous materials will be
Transportation Act, including removed in this Alternative. transported by a licensed transported by a licensed transported by a licensed
Hazardous Materials hazardous waste transporter in hazardous waste transporter in hazardous waste transporter in
Transportation Regulations accordance with state and fecteral accordance with state and federal accordance with state and federal
transportation requirements. transportation requirements. transportstion requirements.
Air Toxies .Hot Spots. Not applicable. No facilities Not applicable. No emissions of Not applicable. No emi68ions of Not applicable. No emissions of
Information and Assessment Act constructed in this alternative. regulated compounds expected regulated compounds expected regulated compounds expected
from groundwater treatment from groundwater treatment from groundwater treatment
facilities. facilities. facilities.
EPA.TB9
103
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~
TABLE 9.1
DOCUMENTATION OF ARARs FOR ALTERNATIVES
UPLAND OPERABLE UNIT
Page 104 of 3
Statue or Regulation
Alternative G
Porter Cologne Water Quality
Control Act
Water Well Standards, State of
California
California Hazardous Waste
Control Laws
California Highway Patrol,
Hazardous Material
RPA.T89
Alternative A
The deep aquifer currently is at
background levels. Tho MCL
for arsenic in the shallow aquifer
currently is being met in the
perimeter network wells.
Alternative A contains no
provisions to remediate before
MCL is reached and no
provisions to meet Basin Plan
limits for surface water runoff
from tho site.
Well construction and
abandonment will be performed
in accordance with these
standards.
Not applicable. No BOil is
removed in this Alternative.
Not applicable. No soil is
removed in this Alternative.
Alternatives B & C
The deep aquifer currently is at
background levels. Tho MCL
for arsenic in tho shallow aquifer
currently is being met in the
perimeter network wells. These
Alternatives contain provisions to
implement remedial action before
MCL is reached. Basin Plan
. limits for surface water runoff
concentrations will be met.
Alternatives D, B, & F
The deep aquifer currently is at
background levels. The MCL
for arsenic in the shallow aquifer
currently is being met in the
perimeter network wells. These
Alternatives contain provisions to
implement remedial action before
MCL is reached. Basin Plan
limits for surface water runoff
concentrations will be met.
Well construction and Well construction and
abandonment will be performed. abandonment will be performed
in accordance with these . in accordance with these
standards. standards.
Bxcavated soil and groundwater
treatment residues will be treated
and disposed as required by state
and federal regulations.
Hazardous materials will be
transported by . licensed
hazardous waste transporter in
accordance with state and federal
transportation requirements.
104
Bxcavated soil and groundwater
treatment residues will be treated
and disposed as required by state
and federal regulations. Treated
soil replaced on site will require
. variance from state hazaradous
waste disposal reguJ,ations.
Hazardous materials will be
transported by . licensed
hazardous waste transporter in
accordance with state and federal
transportation requirements.
The deep aquifer currently is at
background levels. The MCL
for arsenic in the shallow aquifer
currently is being met in the
perimeter network wells. With
removal of nearly all
contaminated soil and
groundwater at the site, it is
unlikely that the MCL will ever
be reached.
Well construction and
abandonment win be performed
in accordance with these
standards.
Bxcavated soil and groundwater
treatment residues will be treated
and disposed as required by state
and federal regulations.
Hazardous materials will be
transported by a licensed
hazardous waste transporter in
accordance with state and federal
transporation requirements.
-------
COMPARISON OFALTERNAT1VES
UPLAND OPERABLE UNIT
1990 Bay Road Site
East Palo Alto, California
Alternative and
Description
Alternative A
Alternative B
Alternative C
Alternative D
Alternative E
Alternative F
Alternative G
Protection of Human
Health and
Environment
Not protective
Protective
Prolecilve
Protective
Protective
Protective
Protective
Compliance with
ARARs
No
Yes
Yes
Yes'
Yes'
Yes'
\
Yes
i
Long-Term
Effectiveness
Not effective
*
More effective than
All. A
More effective than
Alt. A, effectiveness
comparable to All. B
More effective than
Alts. A. B. and C
More effective than
Alts.A.B.C,D.
andF
More effective than
Alts. A. B. C. and 0;
Less effective than
A1I.E
Mosteltecllve;
no long term
maintenance
Reduction of
Toxldty, Mobility,
and Volume
No reduction of M or V
(T can not be reduced
for the contaminants ol
concern)
Reduction ol M and
V In eofl and
groundwater
Reduction ol M and
V In aoB and
groundwator
Reduction olM and V'
In soil and
groundwater, more
reduction of M In soil
than Alts. B or C
Reduction of M and V
In soO and
groundwater, more
reduction of M In soil
than Alls, B.C. and D
Reduction of M and V
In sol) and
groundwater, more
reduction of M In soil
than Alls. B. C. and D
Near-complete
reduction ol M and V
In soil and
groundwater
•
Short-Term
Effectiveness
Not effective
Effective, ARARs met
In short lime
Effective. ARARs
met In short time,
same as All. B
More short-term
Impacts that
Alls. B and C
More short-term
Impacts than Alts. B,
C, and D; ARARs met
In shorter dme than Alt.
0 and In same time as
AllF
More short-term
Impacts that Alls. B.C.
and D; ARARs met In
longer time than Alts.
8, C, and D and In
same lime as Alt. E
Major Impacts to
community and
business during
Implementation.
ongesl lime to achieve
ARARs
Implementability
Implementation
complete
Implementable
Imptementable
More difficult to
Implement than
Alls. A, B, and C
More difficult to
Implement than
Alls. A, B. C and
0; similar to Alt. F
More difficult to
Implement than
Alts. A. B, C and
D: similar to All. E
Most dlflicull to
Implement
Cost
(Net Present Value)
$900.000
$5.600.000 .
$6200.000
$7.800,000
J9.100.000
$9,500.000
$65.000.000
•Requires short term waiver for treatment/recfepositlon
105
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TABLE 9.3
ARSENIC-AFFECTED SOIL: COMPARISON OF ALTERNATIVES
UPLAND OPERABLE UNIT
1990 Bay Rotd Site
But Ptlo Alio. California
Tout mass of Arsenic1 •
74,800 kg
Total volume of affected
soil(>20mg/kg) -91.000yd'
Soil Removed from site:
• Early Action Removal
(>5000mg/kc)
• Early Action Removal
(< 5000 rag/kg)
- Future Removal
- Total Removal
Percent of Total Removed:
Soil Treated at Site:
• Initial Phase (accessible
areas)
• Future Treatment
• Total Treated
Percent of Total Removed or
Treated:
Soil Contained within Slurry
Wall:
Percent of Total Contained within
Slurrv Wall:
Soil Removed, Treated, and/or
Contained:
Percent of Total Removed, Treated.
imd/of Con til nod*
Alternative
B
Miss of Volume
Anenic of Soil
(ki) (vd»)
14.100 1.420
5,900 140
10.000(13%)' 1,260 (IX)'
30.000 3.520
40* 4%
_ _
40ft 4%
43.200 76.800
38ft 84*
73.200 80.320
98* 88*
C
•Mitt Volume
of Anenic of Soil
(k.) (ydl
14,100 1.420
5.900 (40
10.000(13*) 1.260(1%)
30.000 3.520
40ft 4*
_ _
40* 4*
_ —
30.000 3.520
40* 4*
D
Mass Volume
of Arsenic of Soil
ftu) (yd1)
14,100 1,420
5,900 840
10.000(13*) 1.260(1*)
30,000 3.520
40* 4*
11,900 4,330
16,800(22*) 6.600(7*)
28,700 11,000
38* IJ*
78* 16*
43.200 76.800
58* 84*
73,200 80.320
98* 88*
E
Mus Volume
of Anenic of Soil
(V«) (vd»)
14,100 1,420
5.900 840
10.000(13*) 1.260(1*)
30.000 3.520
40* 4*
15.100 7.600
22.500(30*) 12.200(13*)
37,600 20.000
50* 22*
90* . 26*
43.200 76.800
58* 84*
73.200 80.320
98* 88*
F
Mus Volume
of Anenic of Soil
(k«)
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1.0.0
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with federal and state requirements that
are legally applicable or relevant and. appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment (or resource
recovery) technologies to the maximum extent practicable and
satisfies the statutory preference for remedies that employ
treatment to reduce toxicity, mobility, or volume as a principal
element.
Because the remedy will result in hazardous substances
remaining on-site' above health-based levels, a five-year review,
pursuant to CERCLA section 121, 42 U.S.C. Section 9621, will be
conducted at least once every five years after initiation of the
remedial action to ensure that the remedy continues to provide
adequate protection of humaJ? health and the environment. .
11.0 DOCUMENTATION OF SIGHIPIC~ CHANGES
There were no significant changes to the remedy proposed in the
propose9 plan fact. sheet and the remedy selected in this Record
of Decision.
107
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