SEMS-RM DOCID# 100034741
FOURTH FIVE-YEAR REVIEW REPORT FOR
MCCORMICK AND BAXTER CREOSOTING COMPANY SUPERFUND
SITE
SAN JOAQUIN COUNTY, CALIFORNIA
,^t0 sr«%,
<
30
O
\
&
z
LU
O
PREPARED BY
U.S. Army Corps of Engineers
Seattle District
FOR
U.S. Environmental Protection Agency
Region 9
Miri-I API Digitally signed by
A , , IVII v. "I -L MICHAEL MONTGOMERY „ .
Approved by: M0NTG0MERY ,8:20:43 Do*
Michael Montgomery. Director
Region 9 Superfund and Emergency Response Division
U.S. Environmental Protection Agency, Region 9
-------
Errata Sheet
March 28, 2024
Page 14, second paragraph, second sentence (Section 2.4.1) - Replace the sentence "In 2015, the
California Department of Toxic Substances Control (DTSC) became responsible for operation and
maintenance for their parcel (Subarea X)." with "The 2007 Consent Decree between UPRR, DTSC, and
EPA and the 2015 Soil Operable Unit Transfer Agreement both establish that UPRR maintains
responsibility for O&M of the on-Site parcel that is owned by UPRR."
-------
Executive Summary
This is the fourth Five-Year Review of the McCormick and Baxter Creosoting Company (Site) located
in Stockton, California. The purpose of this Five-Year Review is to review information to determine if
the remedy is and will continue to be protective of human health and the environment.
The Site is located at 1214 West Washington Street in the City of Stockton, California in San Joaquin
County. The Site occupies approximately 32 acres near the Port of Stockton at the junction of
Interstate 5 and State Highway 4. The McCormick and Baxter Creosoting Company operated at the
Site for approximately fifty years until 1991. Various wood preservation processes were used at the
Site during its operational history. Preservatives included creosote, pentachlorophenol, arsenic,
copper, chromium, and zinc. Solvents or carriers for these preservatives included petroleum-based
fuels, such as kerosene and diesel, butane, and ether.
In a March 1999 Record of Decision, Environmental Protection Agency (EPA) selected the following
remedies for the groundwater, upland soils, and surface water-sediment contamination at the Site to
protect long-term human health and the environment:
• Extraction of groundwater and on-Site treatment as the interim remedy;
• Excavation of contaminated soil in the eastern portion of the Site and the subsequent
consolidation and capping of these soils in the western portion of the Site;
• Collecting storm water in catch basins to prevent off-Site discharges; and
• In-situ capping of contaminated sediments in Old Mormon Slough, north of the Site.
To date, the interim groundwater remedy has not been implemented. EPA is currently conducting
groundwater monitoring to support the final selection of a groundwater remedy in addition to
conducting several pilot studies to better characterize the groundwater contamination. Although there
is no remedy being implemented for the groundwater, there are no current completed exposure
pathways.
In 2005, EPA issued an Explanation of Significant Differences to clarify that the sediment remedial
action included bank stabilization work to protect the cap and the permanent relocation of the
individual living on a barge in the slough (including relocation of his vessels).
Construction of the soil remedy was completed in 2011, and the remedy is functioning as intended by
the Record of Decision. Soil excavation, consolidation, and capping was successful in removing
exposure pathways to contaminated soil on the Site. However, large cracks continue to appear in the
asphalt cap which may be attributed to either inadequate design and/or construction or possibly
attributed to trespassers driving across the cap. In January 2023, a storm event release from the basins
was assumed to have occurred as evidenced by the full basins and the presence of water in the
discharge pipe.
Construction of the surface water-sediment remedy was completed in 2006, and the remedy continues
to function as intended by the Record of Decision. The sediments in the Old Mormon Slough were
Fourth Five-Year Review for McCormack and Baxter Creosoting Company Superfund Site
i
-------
successfully contained with a sand cap, and the cap remains effective to date. Access to the capped
area of the slough is prohibited through a small boat intrusion barrier and U.S. Coast Guard Safety
Zone.
Exposure assumptions, toxicity data, cleanup levels and remedial action objectives used at the time of
the remedy selection are still valid. Toxicity values for multiple contaminants have changed since the
last Five-Year Review; however, they do not affect the protectiveness of the remedies.
The upland soils remedy currently protects human health and the environment because the remedy
prevents stormwater runoff, minimizes the migration of contaminants from subsurface soils, and
prevents human exposure to contaminated surface soils. However, for the remedy to be protective in
the long-term, the following actions need to be taken: the asphalt cap requires evaluation to ensure the
quality and suitability of the cap remains protective; the stormwater basins require updates for
additional capacity; and physical security access controls need to be updated to ensure trespassers
cannot access the Site to ensure protectiveness.
The surface water-sediment remedy is protective of human health and the environment. All exposure
pathways have been eliminated or controlled through the sand cap, the small boat intrusion barrier,
and the safety zone established by the US Coast Guard.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Contents
Executive Summary i
List of Figures iv
List of Tables v
List of Acronyms and Abbreviations v
1. Introduction 1
1.1. Background 3
1.2. Physical Characteristics 4
1.3. Hydrology 6
2. Remedial Actions Summary 7
2.1. Basis for Taking Action 7
2.2. Remedy Selection 7
2.2.1. Uplands Soil Remedy 7
2.2.2. Surface Water-Sediment Remedy 9
2.2.3. Groundwater Remedy 10
2.3. Remedy Implementation 10
2.3.1. Soil Remedy 10
2.3.2. Surface Water-Sediment Remedy 11
2.3.3. Groundwater Remedy 11
2.3.4. Institutional Controls 14
2.4. System Operations/Operation and Maintenance 14
2.4.1. Operations and Maintenance Requirements 14
2.4.2. Significant Operations and Maintenance over the Past Five Years 15
3. Progress Since the Last Five-Year Review 18
3.1. Previous Five-Year Review Protectiveness Statement and Issues 18
3.2. Work Completed at the Site During this Five-Year Review Period 18
4. Five-Year Review Process 19
4.1. Community Notification, Involvement and Site Interviews 19
4.1.1. Five-Year Review Public Notice 19
4.1.2. Site Interviews 19
4.2. Data Review 20
4.2.1. Stormwater Analysis 20
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site iii
-------
4.2.2. Sediment Cap 22
4.2.3. Groundwater 23
4.2.4. Sustainability 26
4.3. Site Inspection 26
5. Technical Assessment 27
5.1. Question A: Is the remedy functioning as intended by the decision documents?.... 27
5.2. Question B: Are the exposure assumptions, Toxicity Data, Cleanup Levels, and
Remedial Action Objectives Used at the Time of Remedy Selection Still Valid? 28
5.3. Question C: Has Any Other Information Come to Light That Could Call into Question
the Protectiveness of the Remedy? 28
6. Issues/Recommendations 29
6.1. Other Findings 30
7. Protectiveness Statement 30
8. Next Review 31
Appendix A: List of Documents Reviewed 32
Appendix B: Site Chronology 33
Appendix C: Applicable or Relevant and Appropriate Requirements Assessment 35
Appendix D: Toxicity Assessment 37
Appendix E: Public Notice 40
Appendix F: Interview Forms 41
Appendix G: Site Inspection Report and Photos 43
List of Figures
Figure 1. Historic Site Use Map 3
Figure 2. Location Map 5
Figure 3. Detailed Site Map 6
Figure 4. Extent of Acenaphthene Contamination (2017) 12
Figure 5. Extent of Naphthalene Contamination (2017) 13
Figure 6. Operations and Maintenance Inspection Observations, February 2021 16
Figure 7. Operations and Maintenance Inspection Observations, February 2022 17
Figure 8. Basins 1, 2, and 4 water level on January 12, 2023 22
Figure 9. Extent of Naphthalene in D-zone (2017) 24
Figure 10. Extent of Acenaphthene in D-zone (2017) 25
iv Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
List of Tables
Table 1. Five-Year Review Summary Form 2
Table 2. Soil Cleanup Levels from 1999 Record of Decision 8
Table 3. Sediment Cleanup Levels (Old Mormon Slough) from 1999 Record of Decision 9
Table 4. Summary of Implemented Institutional Controls 14
Table 5. Status of Recommendations from the 2018 Five-Year Review 18
Table 6. Stormwater Analytical Results (2020 through January 2023) for the Site 21
Table 7. Sediment Analytical Results from 2020 Operations and Maintenance Report 23
Table 8. Issues and Recommendations Identified in the Five-Year Review 29
Table 9. Protectiveness Statement 30
List of Acronyms and Abbreviations
cPAH
Carcinogenic Polycyclic Aromatic Hydrocarbons
DTSC
California Department of Toxic Substances Control
EPA
United States Environmental Protection Agency
NAPL
Non-aqueous phase liquid
PAHs
Polynuclear aromatic hydrocarbons
PCP
Pentachlorophenol
ROD
Record of Decision
Site
McCormick and Baxter Creosoting Company Superfund Site
USACE
United States Army Corps of Engineers
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
v
-------
1. Introduction
The purpose of a Five-Year Review is to evaluate the implementation and performance of a remedy in
order to determine if the remedy will continue to be protective of human health and the environment. The
methods, findings, and conclusions of reviews are documented in Five-Year Review reports. In addition,
Five-Year Review reports identify issues found during the review, if any, and document
recommendations to address them.
The U.S. Environmental Protection Agency (EPA) is preparing this five-year review pursuant to the
Comprehensive Environmental Response, Compensation, and Liability Act Section 121, 40 Code of
Federal Regulation Section 300.430(f)(4)(ii) of the National Contingency Plan and EPA policy.
This is the fourth Five-Year Review for the McCormick and Baxter Creosoting Company Superfund Site
(Site). The triggering action for this statutory review is the completion of the previous Five-Year Review
Report on September 24, 2018. The Five-Year Review has been prepared because hazardous substances,
pollutants, or contaminants remain at the Site above levels that allow for unlimited use and unrestricted
exposure.
The Site consists of three Operable Units1. The upland soils and the surface water-sediment operable units
will be addressed in this Five-Year Review. An interim remedy has been selected for the groundwater
operable unit, but the groundwater remedy has not been implemented and will not be discussed in detail.
The McCormick and Baxter Creosoting Company Superfund Site Five-Year Review was led by Sania
Kamran, EPA Region 9 Remedial Project Manager. Participants included Cynthia Wetmore, EPA Region
9 Superfund Five-Year Review Coordinator, Cynthia Ruelas, EPA Region 9 Superfund Five-Year
Review co-coordinator, and from the U.S. Army Corps of Engineers (USACE): Jake Williams, Five-Year
Review Project Manager, Justin McNabb, hydrogeologist, Katie Richwine, physical scientist, and Charity
Meakes, environmental engineer. The review began on October 5, 2022.
1 During cleanup, a Site can be divided into distinct areas depending on the complexity of the problems associated
with the Site. These areas, called operable units, may address geographic areas of a Site, specific Site problems, or
areas where a specific action is required.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
1
-------
Table 1. Five-Year Review Summary Form
SITE IDENTIFICATION
Site Name: McCormick and Baxter Creosoting Company
EPA ID: CAD009106527
Region: 9
State: CA
City/County: Stockton/San Joaquin
National Priorities List Status: Final
Multiple Operable Units? Yes
Has the Site achieved construction completion? No
Lead agency: EPA
Author name: Sania Kamran, Project Manager
Author affiliation: EPA
Review period: 10/5/2022 - 5/12/2023
Date of Site inspection: 3/16/2023
Type of review: Statutory
Review number: 4
Triggering action date: 9/24/2018
Due date (five years after triggering action date): 9/24/2023
2
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
1.1. Background
The McCormick and Baxter Creosoting Company used various wood preservation processes at 1214
West Washington Street within the City of Stockton, San Joaquin County, California from 1946 until
1991. Petroleum-based fuels including kerosene and diesel, butane, and ether were used as carriers for
wood preservatives such as creosote, pentachlorophenol (PCP), arsenic, copper, chromium, and zinc. The
primary facility areas identified as principal sources of contamination include the main processing area,
oily waste ponds area, Cellon process area, and PCP mixing shed/butt tank area (Figure 1).
Figure 1. Historic Site Use Map
Soil contamination occurred through the various handling processes and some on-Site disposal of
products containing the preserving chemicals. Sediment contamination resulted from storm water runoff,
direct spills of chemicals during the processing operations and unloading of chemicals from barges, and
migration of non-aqueous phase liquid (NAPL) from the upland portion of the Site. Groundwater
contamination occurred through free-phase and dissolved-phase transport through the vadose zone and
spread as a result of advective and dispersive properties of the aquifer and chemical properties.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
3
-------
Contamination at the Site was discovered in 1977 when a fish kill occurred in the waters of the New
Mormon Slough and the Stockton Deepwater Channel following a major storm event. This prompted an
investigation into the cause. It was discovered that PCP-laden stormwater runoff from the McCormick
and Baxter facility discharged into New Mormon Slough via a connection to the City of Stockton storm
drain system. Based on the results of a preliminary assessment and Site inspection, EPA proposed adding
the McCormick and Baxter Creosoting Company Site to the National Priorities List and finalized the
listing in October 1992.
1.2. Physic icierisiics
The McCormick and Baxter Creosoting Company Superfund Site occupies approximately 32 acres near
the Port of Stockton at the junction of Interstate 5 and State Highway 4 (Figure 1). An 8-acre parcel of
land in the southeastern portion of the Site is owned by the Union Pacific Railroad. Old Mormon Slough
forms the northern boundary of the Site, Washington Street forms the southern and eastern boundaries,
and an industrial facility (located at the Port of Stockton Turning Basin) is located to the west of the Site.
Regionally, the Site is situated on the margin of the Sacramento River-San Joaquin River Delta in the
Great Valley geomorphic province of California. The terrain has low relief, with elevations ranging from
8 to 15 feet above mean sea level.
Non-potable supply wells (for either industrial or agricultural uses) exist to the northeast of the Site;
however, the high salinity and total dissolved solids content of the water indicate that potable supply
wells would not likely be installed near the Site. The nearest active municipal water supply wells to the
Site are situated over 3.5 miles to the northeast and at a depth greater than 200 feet below ground surface.
Old Mormon Slough was historically used for water-borne transportation of lumber and other goods, and
the western end of the slough, where it adjoins the Turning Basin, is still used as a docking area for barges
and other vessels. Nearby surface water bodies include New Mormon Slough, the Stockton Deepwater
Channel, and the San Joaquin River.
The Site is predominately in an industrial land-use area. Other nearby land uses include light
manufacturing and residential. The nearest residential areas are located approximately 500 feet southwest
of the Site and another 750 feet southeast of the Site, beyond Interstate 5 and State Highway 4 junction.
The 1999 ROD identified then-current and projected land use of the Site as continued industrial. This is
consistent with the present land use at the Site. It is also consistent with the City of Stockton's 2035
General Plan, which designates the immediate Site area as industrial with commercial land use to the
north, low-density residential to the southwest and medium-density residential to the southeast. The City
of Stockton has a population of 322,120 (as of the 2020 US Census), most of whom reside within five
miles of the Site.
4
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Figure
1
Legend
%
Site Location
Map Source Deiorme, NAV7EQ USGS.
totemi^s, iPC NRCAK tsri Japan. METl
Bri China {Hong Kong l Esri (Thailand!.
TomTom, 2012
Site Location Map
McCormickA &axt« Superfund Site
1214 Washington Street
Stoc fclo*v California
Geosyntec^
consultants
Project Hos SAC147V February 2022
Source: Geosyntec, 2022. 2021 Annual Operation and Maintanance Report.
Figure 2. Location Map
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
5
-------
weoer7Ave[
¦Detention Basing'
Soil Berm Along J
sTough —¦ "
! Detention]
^ BasinfrtB
McCORMiCK & BAXTER PARCEL
\ Sol Berm Along
T Prop^rtyXine >
[Soil Berm Along
• Perimeter
'Swale^
Subarea X
Swale-
.Detention^
Basin 3
Main1 Basin]
Detention . . \'
JT ; Forebay )
Subarea Y
: AsphaltrcConcreteCa^
Railroad TracKs
Legend
® Basin Outlet *—— Fence
A Rre Hydrant (Not in Service) Basin Discharge Pipe (Underground)
5 Junction Box Site Boundary
© Manhole
6 Monitoring Well
400 200 0 400 Feet
Notes
' Detention Basin 4 is ined.
All site features are approximate and
derived from Arcacis (2014).
Imagery source: Google Earth Pro,
August 2019.
Site Layout
McCormick & Baxter Superfund Site
1214 Washington Street
Stockton, California
Geosyntec^
consultants
Project No.: SAC147V
February 2022
Figure
2
Source: Geosyntec, 2023. 2022 Annual Operation and Maintanance Report.
Figure 3. Detailed Site Map
1.3. Hydrology
The Site is located within the Eastern San Joaquin Subbasin of the San Joaquin Valley Groundwater
Basin. The Eastern San Joaquin Subbasin is bounded by the Mokelumne River on the north and
northwest, the San Joaquin River on the west, the Stanislaus River on the south and bedrock on the east.
Aquifers beneath the Site consist of a shallow aquifer that extends from approximately 15 feet below
ground surface to 200 feet below ground surface and a deeper aquifer that extends from 200 to 1000 feet
below ground surface. The shallow and the uppermost portion of the deep aquifer beneath the Site have
been subdivided into five water-bearing zones designated as Zones A through E. These zones represent
intervals of intermixed sands, clays, and silts.
The five zones are not hydraulically isolated from one another but are separated by silt-sand mixtures
which impede (but do not prevent) groundwater movement between zones. Groundwater flow has varied
in direction from northeast to southeast due to seasonal differences and multiple aquifer zones plus nearby
6
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
historical water extraction (pumping from City of Stockton production wells closest to the Site ended in
1993). With few exceptions, the observed vertical gradient of flow between aquifer zones has been
downward.
Groundwater elevation measurements during the previous Five-Year Review ranged from 10 feet below
ground surface near the Old Mormon Slough to 23 feet below ground surface near the southern perimeter
of the Site.
2. Remedial Actions Summary
2.1. Basis for Taking Action
The primary contaminants of concern found in groundwater, soils, and sediments at the Site include PCP,
carcinogenic polycyclic aromatic hydrocarbons (cPAHs), arsenic, dioxin/furans, and naphthalene.
Groundwater concentrations exceed federal drinking water standards. The primary threat to human health
is posed by incidental ingestion and dermal absorption by on-Site workers exposed to on-Site soils.
Sediment contamination related to the Site was limited to Old Mormon Slough. Two resident fish -
bluegill and white catfish - and two fish-eating birds - great blue heron and double crested cormorant -
migrate to the Old Mormon Slough and reside there for extended periods of time during sensitive life
stages. PAHs posed a risk to aquatic receptors, most notably for fish and benthic fauna. Dioxin was
estimated to be a potential low risk to bird and fish reproduction and health. Pentachlorophenol (PCP)
was estimated to have a potential impact on both fish and benthic animals. However, as PCP was present
but not widely distributed in sediment, no ecological risk was identified.
2.2. nedy Selection
On March 31, 1999, EPA selected final remedies for the upland soils and surface water sediment and an
interim remedy for groundwater.
2.2.1. Uplands Soil Remedy
EPA established the following the remedial action objectives for upland soils in the 1999 ROD:
• Prevent human exposure to contaminated surface soils via direct contact, ingestion, or
inhalation.
• Prevent storm water runoff of contaminated surface soils into adjacent surface water bodies.
• Prevent or minimize the migration of contaminants from subsurface soils and from Old
Mormon Slough sediment to groundwater.
EPA divided the Site soils into three subareas: X, Y, and Z with delineations based on lateral and vertical
extent of contaminants of concern at concentrations above surface soil cleanup levels (Figure 2, Table 2).
Subareas Y and Z cover the same footprint at different depths.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
7
-------
Subarea X includes soil contamination in the eastern portion of the Site where historically treated wood
was stored throughout the area. The resulting soil contamination was shallow (1 foot below ground
surface) with arsenic as the most widely distributed contaminant of concern.
Subarea Y includes soil contamination to 13 feet below ground surface in the western portion of the Site
that historically operated as the central processing area with the oily waste ponds (including areas used for
treated wood storage and the former stormwater collection ponds). Subarea Y encompasses vadose zone
contamination for all organic and inorganic contaminants of concern.
Deeper soil contamination underlying Subarea Y (below 13 feet below ground surface or saturated soil)
makes up the third subarea, Subarea Z.
Soil cleanup standards as identified in the ROD, are shown in Table 2.
Table 2. Soil Cleanup Levels from 1999 Record of Decision
Chemical
Cleanup Levels (m<>/kj> except as noted)
Basis for Cleanup Level
Benzo(a)pyrene
3.6
Acenaphthene
1100
Anthracene
57
Fluorene
900
1999 EPA Region 9 Preliminary Remediation
Goals (PRGs) adjusted to a 10"5 risk.
Naphthalene
190
Pyrene
1000
Pentachlorophenol
150
2,3,7,8-TCDD
(Dioxin)
1 ng/kg (dry weight, organic carbon normalized)
Arsenic
30
ju.g/kg = microgram per kilogram
The selected uplands soils remedy consisted of excavating all the Subarea X contaminated soil with
concentrations exceeding soil cleanup levels, moving it to a separate location within the Subarea Y
boundary, and covering the consolidated Subarea X soils and the Subarea Y soils with a cap. Subarea Y
and Z soils were not excavated. The components of the remedy included:
• Site clearance and debris removal;
• Excavation of Subarea X soils;
• Initial grading of the area to be capped;
• Backfilling of Subarea X excavations with clean import fill;
• Backfilling and grading of the stormwater ponds with a portion of excavated Subarea X soils
(approximately 10,000 cubic yards)2;
2 Stormwater ponds were once located in Subarea Y. Because Subarea Y would ultimately be capped, contaminated
soil from Subarea X was used as fill.
8
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
• Consolidation of remaining Subarea X soils in Subarea Y, and cap construction over the
contaminated soil;
• Cap maintenance;
• Stormwater catch basins installation; and
• Institutional controls, including all or some of the following: Site access controls, land use
restrictions, and proprietary and/or governmental restrictions.
2.2.2. Surface Water-Sediment Remedy
For the surface water-sediment remedy, the EPA identified the following remedial action objectives in the
1999 ROD:
• Reduce potential risks to human health from the consumption of fish contaminated with Site-
related chemicals.
• Prevent humans and aquatic organisms from direct contact with sediment having contaminants in
excess of risk-based concentrations or that have been shown to be toxic to aquatic organisms.
• Prevent or minimize the migration of contaminants from Old Mormon Slough sediments into the
surface water column.
• Prevent or minimize the migration of contaminants from Old Mormon Slough sediments to
groundwater.
• Allow full attainment of the beneficial uses of surface waters in the area of the Site, including fish
and shellfish harvesting and the protection of aquatic life and wildlife.
Sediment cleanup standards (none for surface water), as identified in the ROD, are shown in Table 3.
Table 3. Sediment Cleanup Levels {Old Mormon Slough) from 1999 Record of Decision
( €illl;i111ill:ill 1 nl'
C ii mi-I'll
('li-;illll|> Sl;ill(l:iI'll
IS:isis In|-C k;imip Sl;iml;inl
Total PAHs
333 mg/kg (dry weight,
organic carbon normalized)
Site-specific risk-based Maximum Sediment Concentrations
developed in the Ecological Risk Assessment
2,3,7,8-TCDD
(Dioxin)
21 ng/kg toxicity equivalence
mg/kg = milligrams per kilogram
ng/kg = nanogram per kilogram
Sediment contamination related to the Site was limited to Old Mormon Slough located directly adjacent
to the former McCormick and Baxter facility. EPA divided Old Mormon Slough into four subareas
adjacent to the Site central processing area, the area adjacent to the oily waste ponds area, and the mouth
of the slough.
The selected sediment remedy consisted of in-situ capping of contaminated Old Mormon Slough
sediments in order to isolate areas of primary contamination (approximately three-fourths of the slough)
by blanketing them with clean fine sand with a minimum thickness of two feet. The cap materials were to
be armored with riprap and a gravel filter layer where necessary to prevent erosion. The capped portion of
the slough would run from just north of the oily waste ponds area to the east end of the slough.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
9
-------
The selected sediment remedy also included the following institutional controls to:
• Limit navigational access to the slough,
• Warn visitors of Site hazards,
• Limit future use of Old Mormon Slough to appropriate uses, and
• Control future dredging of the slough to prevent disturbance of residual sediment contamination
in the mouth of the slough.
On September 27, 2005, EPA signed an Explanation of Significance Differences to implement the
following changes to the surface water-sediment remedy:
• Include bank stabilization along the slough to prevent erosion of contaminated soil from re-
contaminating the sediment cap;
• Relocate a resident living on a barge in the slough for cap construction and future protection of
the sediment cap; and
• Limit vessel access to the slough via a placement of log boom and additional signage.
2.2.3. Groundwater Remedy
Remedial action objectives identified in the ROD for the groundwater remedy are as follows:
• Prevent human exposure to groundwater contaminated above drinking water standards.
• Prevent the further spread of the groundwater contamination plume.
• Remove non-aqueous phase liquids (NAPL) to the extent practicable to reduce the continuing
source to groundwater contamination.
• Contain NAPL sources that cannot be removed.
• Evaluate further groundwater risk reduction (40 CFR Section 300.430(a)(l)(iii)(F)).
Groundwater contamination at the Site was limited to semi-volatile organic compounds and to a lesser
extent, dioxins. The interim groundwater remedy included groundwater extraction and on-Site treatment
with discharge into surface water permitted by the National Pollution Discharge Elimination System
(NPDES) and reuse for irrigation or industrial uses. In addition, NAPL would be extracted using
dedicated wells and then sent for off-Site recycling or treatment/disposal.
olementation
2.3.1. Soil Remedy
Union Pacific Railroad performed construction activities, including excavation of soil in Subarea X,
consolidation of contaminated soil on Subarea Y, and capping the consolidated waste with 6 inches of
compacted aggregate base overlain by 2 inches of asphaltic concrete over two construction seasons from
May 2009 through February 2011.
Union Pacific Railroad recorded a land use covenant in December 2007 that limits the use, protects the
integrity of remedial systems, and provides control over future grading and groundwater use on their
10
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
portion of the Site. Implementation of the land use covenant(s) for the remaining parcels is still in
progress.
2.3.2. Surface Water-Sediment Remedy
EPA began bank stabilization in October 2002 for the surface water-sediment remedy and EPA completed
the fine-sand subaqueous cap (minimum thickness 2 feet; average thickness 2.6 feet) in 2006. Before the
cap was completed in 2006, all vessels and occupants living on the vessels within the Old Mormon
Slough were removed to complete the capping construction as required by the decision document. EPA
also installed the log boom at the outer end of the slough to prevent vessel traffic from entering and
damaging the cap, and to also prevent people from fishing.
On August 26, 2013, EPA and the US Coast Guard replaced the log boom with a Whisper Wave Small
Craft Intrusion Barrier due to continued breaching of the log boom. On October 1, 2013, the US Coast
Guard established a Safety Zone in the capped portion of the slough to prohibit all vessels and personnel
not associated with EPA from entering or transiting the capped area.
2.3.3. Groundwater Remedy
The interim groundwater remedy has not been implemented and groundwater data has not been collected
since 2017. The primary chemicals of concern are naphthalene, acenaphthene, and PCP. Naphthalene and
acenaphthene have been principally tracked due to 1) their relative abundance in coal tar creosote and
relatively high mobility (naphthalene), 2) having the largest dissolved phase plumes (acenaphthene), and
3) their greatest relative magnitude of exceedance of the preliminary cleanup criteria. The previous Five-
Year Review compared concentrations over a 13-year period (2004 to 2017) and concluded that the
overall concentrations and extent of the contamination has not significantly varied.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
11
-------
Legend
^ A-8 Well ID
4000 Concentration (ug/L)
(7ft /1999) (Date of last sample)
Monitoring Well Sampled
Monitoring Well Not Sampled
Acenaphthene Contour (ug/L)
NAPL (calculated using MVS)
| CD Aquitard
| DZone
DE Aquitard
7/15/2015
ONS-2D
0.26
4/24/2006
DSW-1D#
100
7/14/2015
OPS-ID
0.029
5/4/2006
OFS-S4D i
A
70(301$
* OS-6D
.* 0.48
~*T*/16/2015
OS-5D
12,
7/16/2015
McCormick and Baxter Superfund Site
Figure H-2
Acenaphthene in D Zone
Round 26 (April 2017)
Figure 4. Extent of Acenaphthene Contamination (2017)
12
Fourth Five-Year Review for McCormick arid Baxter Creosoting Company Superfund Site
-------
Legend
A-8
4000
(7/1/1999)
Well ID
Concentration (ug/L)
(Date of last sample)
Monitonng Well Sampled
Monitoring Well Not Sampled
Naphthalene Contour (ug/L)
NAPL (calculated using MVS)
| CDAquitard
| DZone
DEAquitard
7/J4S015
©3-6 D
<0.05
7/16/2015
7««V2015
roGRID. IQNiianS the^felSi
McCormicK and Baxter Superfund Site
Figure H-4
Naphthalene in D Zone
Round 26 (April 2017)
Figure 5. Extent of Naphthalene Contamination (2017)
Fourth Five-Year Review for McCormick and Baxter Creosotirig Company Superfund Site
13
-------
2.3.4.
Institutional Controls
Institutional controls involve controlling exposure to contaminated media by controlling access,
implementing engineering controls (e.g. fencing and signs), and implementing land use restrictions.
Table 4. Summary of Implemented Institutional Controls
Media.
Kll»illCCrcd
Controls,
and A rcas
Institutional
Controls Culled
lor in the
Decision
Documents
Impeded
ParccKs)
Objcctnc
Title iind Diile (or
pliiiined)
Soil
Yes
Subarea X
145-20-010
I .and Use restrictions (protects
the integrity of remedial systems,
and provides control over future
grading and groundwater use on
the Site)
Environmental and I.and Use
Covenant (instrument No.
2007-217-413, recorded
December 31, 2007)
Soil
Yes
Subarea Y
145-20-001,
145-20-014,
145-19-10,
145-19-11,
145-19-12
Site access control, land use
restrictions (prohibiting
excavation, providing appropriate
notices of hazardous waste).
In progress
Sediment/
Surface
Yes
Old Mormon
Slough
Limit navigational access,
provide warning signs, control
dredging to prevent disturbance.
2006
2,4, System Operations/Operation aintenance
2.4.1. Operations and Maintenance Requirements
A Soil Remedy Operation and Maintenance Manual was prepared in May 2014 on behalf of Union
Pacific Railroad for the entire Site. In 2015, the California Department of Toxic Substances Control
(DTSC) became responsible for operation and maintenance for their parcel (Subarea X). GeoSyntec
Consultants Inc., consultants for DTSC, updated the operations and maintenance plan on February 25,
2020. Operation and maintenance activities include maintaining the asphalt cap, mowing the revegetated
areas, maintaining the on-Site basins, and stormwater monitoring. GeoSyntec conducts annual Site
inspections for the soil remedy, which includes checking the asphalt for any cracks and sealing them,
repairing any signs of failure or trespassing, and observing whether Site drainage is working properly.
Operation and maintenance activities for the sediment cap includes maintenance of the southern bank of
Old Mormon Slough, periodic bathymetric survey of the sediment cap, sampling of sediment cap and
14
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
inspection and repair of access controls. DTSC conducts an annual inspection of the southern bank of Old
Mormon Slough and access controls and periodic sediment soil sampling. Bathymetric surveys will be
conducted on the analytical results of the cap material.
EPA retains responsibility for the development of the groundwater remedy and Site security requirements.
2.4.2. Significant Operations and Maintenance over the Past Five
Years
In May 2020, GeoSyntec conducted the 2020 annual inspection, which identified several major cracks
and grown vegetation throughout the asphalt cap. GeoSyntec also inspected the three on-Site basins and
determined that the basins had excess vegetation that needed mowing. GeoSyntec also inspected the
southern bank of the Mormon slough and the access controls. In June 2020, Geosyntec collected sediment
samples and stormwater samples, and completed fence repairs, vegetation removal, and asphalt cap crack-
filling that were identified in the May 2020 inspection of needing action.
In June 2021, Geosyntec conducted the 2021 annual inspection of the asphalt cap, the basins, the Old
Mormon Slough southern bank and access controls. Several cracks were observed on the asphalt cap, in
addition to a large subsidence area. Geosyntec also observed three to five encampments located inside the
perimeter fences, along with 15 fence holes, two barbed entanglements, and four damaged fence posts.
The small craft intrusion barrier at the mouth of the slough was observed to be split in half. Geosyntec
removed excess vegetation, repaired the small craft intrusion barrier and patched the asphalt cap in the
fall of 2021. GeoSyntec also collected stormwater samples from Basins 1, 2, and 4, the results of which
are discussed in the Data Review.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
15
-------
4^- -K.-5'sl Wt
Legend
Barbed wire repair
Damaged fence pole
O Hole In fence
/\ Subsidence
@ Basin Outlet
£ Ore Hydrant (Mot in Service)
@ Manhole
•—— Fence
Basin Discharge Pipe
I Underground)
~~1 Parcels
—— Site Boundary
Notes
' Detention Basin 4 is Ined.
All site features are approximate and
derived from Arc ads (2014)
Imagery source: Google Earth Pro
August 2019.
400 200
Operation and Maintenance
Inspection Observations
McCorm»ck & Baxter Super fund Site
1214 Washington Street
Stockton. California
Geosyntec^
consultants
Project No : SAC 147V
February 2022
Figure
3
Figure 6. Operations and Maintenance Inspection Observations, February 2021
On May 22, 2022, GeoSyntec conducted the 2022 annual inspection of the soil and sediment remedy.
Again, several cracks that needed repair were observed in the asphalt cap and vegetation removal was
necessary. Ten temporary camps were observed inside the perimeter fence. The southern bank and the
small craft intrusion barrier did not need any repairs. RDM Environmental, under Geosyntec oversight,
made the recommended repairs later in May and early June of 2022.
16
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
<¦ 4 bom J©14t
Coc«jfe t«rth Fm
AMQUkt iO't
Geosyntec^ | Figure
consultants
Operation and Matlneiunce
Inspection Observations
Figure 7. Operations and Maintenance Inspection Observations, February 2022
Stormwater samples were collected to monitor the stormwater quality to ensure it is compliant with City
of Stockton Municipal Utilities District criteria. The first sampling event on December 9, 2022, had low
water conditions. The second sampling event on January 12, 2023, followed a sequence of major storm
events and assumed discharge to the City of Stockton sewer. During the January storm event discharge
from the basins was assumed to have occurred as evidenced by the full basins and water in the discharge
pipe.
EPA visited the Site on October 19, 2022, observed damaged fence in multiple locations, including some
with holes large enough for vehicles to pass through and multiple signs of trespassing including tents,
RVs, and cars. EPA also observed an approximately one-foot long and six-inch deep hole in Subarea X.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
17
-------
3. Progress Since the Last Five-Year Review
Pnevio ¦ /iew Protectiveness Statement and Issues
The protectiveness statement from the 2018 Five-Year Review for the McCormick and Baxter Superfund
Site stated the following:
The remedy for the soils operable unit is currently protective of human health and the
environment. All exposure pathways have been eliminated or controlled through the installation
of an asphalt cap and partial implementation of institutional controls. In order to be protective in
the long-term, the land use covenant needs to be recorded for the McCormick and Baxter
property.
The remedy for the surface water-sediment operable unit is protective of human health and the
environment. All exposure pathways have been eliminated or controlled through the installation
of the sand cap and small boat intrusion barrier and the implementation of institutional controls.
The 2018 Five-Year Review included one issue and recommendation. The recommendation and the
current status are discussed below.
Isslll-
kl'l'lllllllH-IHhllillll
( urmil
Sl;i 1 lis
( urmil Impk-nu-iil.iliiui Si;iius
( iiinpk'liiiii
l);ili- (if
;i|)|)lii;il)k)
The Environmental
Land Use Covenant
has not been recorded
on the McCormick and
Baxter owned portion
of the property.
Implement a Land
Use Covenant on
the property.
Ongoing
Once the groundwater remedy is selected,
EPA anticipates that the property will be
redeveloped. DTSC drafted a land use
covenant for the remaining parcels that
will also include protecting the integrity of
the asphalt cap.
enler a date
Work CompleU ', | th 'iew Period
Geosyntec field staff, contractors to DTSC, collected annual stormwater sampling events and another
sampling event after a major storm in 2023.
As of April 11, 2023, camps on-Site have been displaced by Stockton Code Enforcement officers, and
vehicles on-Site have been towed. Stockton Code Enforcement plans to place concrete blocks by the east
side entrance to prevent unauthorized vehicles from accessing the Site.
EPA continued on-Site work related to the groundwater remedy implementation. In 2019, EPA conducted
a phytoremediation study to determine the feasibility of using salt-tolerant hybrid poplar trees to decrease
contaminant concentrations in groundwater pumped from a deep aquifer. After the phytoremediation
study was complete, vandalism and theft were prevalent with the perimeter fence being breached multiple
times and equipment being taken from the Site. EPA sampled six wells in 2021, as part of the
18
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
phytoremediation study, and will be conducting a more comprehensive groundwater monitoring event in
Fall 2023.
Also, with respect to the implementation of the groundwater remedy, Environmental International
Corporation, a contractor for USACE3, conducted NAPL recovery tests at existing Site wells during
September and October 2019 to evaluate the feasibility of increasing NAPL recovery efficiencies in the
existing Site wells. The test was successful at one well; however, the age of most wells (approaching 40
years), varying degrees of clogged screens, and other factors led to limited recovery of NAPL and a
recommendation to not proceed with additional long-term NAPL recovery.
4. Five-Year Review Process
4.1. iiy Notificat Jweme >ite Interviews
4.1.1. Five-Year Review Public Notice
A public notice was made available by a newspaper posting and press release in The Record on Monday,
December 19, 2022, stating that there was a Five-Year Review and inviting the public to submit any
comments to the EPA (Appendix E). No public comments were received. The results of the review and
the report will be made available at the Site information repository located at the addresses below:
Stockton-San Joaquin County
Cesar Chavez Central Library
605 North El Dorado Street
Stockton, CA, 95202
(209) 937-8221
and
Superfund Record Center
75 Hawthorne Street, Room 3100
San Francisco, CA, 94105
(415) 947-8717
Email: R9records@epa.gov
4.1.2. Site Interviews
During the Five-Year Review process, interviews were conducted to document any perceived problems or
successes with the remedy that has been implemented to date. EPA solicited written responses to
questions from DTSC and an environmental engineer from USACE, Sacramento District. The specific
responses of individuals from each group can be seen in Appendix F.
3 EPA has entered into an interagency agreement with the USACE Sacramento District to conduct work on the Site.
EPA has a separate agreement with the USACE Seattle District to conduct the Five-Year Reviews.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
19
-------
An engineering geologist from DTSC provided response and stated that the remedy is functioning as
expected; however, there are several issues noted during the past few years. The soil cap is functioning as
expected, but the stormwater management system does not have sufficient capacity to manage
stormwater. During a major storm in early January 2023, all basins were filled beyond their capacity.
Additionally, flooding was noted throughout the majority of Subarea X due to poor grading, and the soil
supporting the asphalt and the concrete edges was compromised, leading to more cracking and potholes
(Refer to Figure 2 for the location of Subarea X within the Site). The engineering geologist mentioned
that the stormwater blockages were addressed; however, the basins were beyond their capacity and a work
plan will be created to address the potential copper exceedances measured in stormwater. In addition,
trespassing and homeless encampments are a major health and safety issue for both on-Site workers and
Site contractors. The accumulation of dry vegetation is also an issue because the owner of the Union
Pacific Railroad Parcel refuses to carry out routine vegetation abatement on the property, which has
become extremely dry during the summer months and poses a fire risk.
An environmental engineer from USACE Sacramento District provided responses and stated concerns
about Site security in reference to the multiple holes in the fence and the unhoused individuals having
access to the property. He believes that the operation and maintenance frequency visits are not sufficient
to prevent fence damage or trespassing. In addition, the 2017 signs have been sun-damaged, vandalized,
and are possibly missing at some locations throughout the Site. The environmental engineer recommends
additional security checks that could include up to full-time security and updating the signs to ensure the
Site is protected from trespassers and vandals.
4. '101/1/
4.2.1. Stormwater Analysis
Stormwater sampling was performed at least once per year between 2020 and 2023. In 2020 and 2021,
DTSC reported both total and dissolved copper concentrations in stormwater detention Basins 1, 2, and 4
above the City of Stockton Municipal Utilities District criteria limits and exceedances of total PAHs in
Basins 2 and 4 (Table 5). However, since the discharge limits only apply to stormwater discharged off-
Site and no stormwater has historically been discharged off-Site, no violation of the City discharge limit
occurred. Water levels where low during the December 2022 sampling event; however, samples were
taken from the main basins for the January 2023 sampling event following a major storm that inundated
all three basins and the water was assumed to have discharged into the city sewer system (Figure 5).
Sampling results again exceeded discharge limits for total copper in Basins 1 and 4, dissolved copper in
Basin 1, and PAHs in Basin 4. Therefore, water with concentrations exceeding the discharge limits may
have been discharged off-Site during the storms in early January of 2023.
20
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Table S. Stormwater Analytical Results {2020 through January 2023) for the Site
Sample ID
Stormwater
Basin
Sample
Date
Copper
(mg/L)
Copper
(Dissolved)
(mg/L)
Total
PAHs1
(ms/l)
Discharge Limit per Work Plan (Geosyntec, 2020)
0.01
0.01
0.049
MB-SW-BAS01-20201221
Basin 1
12/21/2020
0.02
0.0095
0.279
MB-SW-BAS01-
202010125
1/25/2021
0.021
0.016
0.047
MB-BAS01-20211102
11/2/2021
0.03
0.023
0.16
MB-BAS1-20211227
12/27/2021
0.028
0.021
ND
20211209-BS1
12/9/2022
0.18
0.17
ND
20230112-BS1
1/12/2023
0.027
0.019
0.037
MB-SW-BAS02-20201221
Basin 2
12/21/2020
0.0083
0.0071
0.023
MB-SW-BAS02-
202010125
1/25/2021
0.0082
0.0073
0.024
MB-BAS02-20211102
11/2/2021
0.014
0.0035
0.040
MB-BAS2-20211227
12/27/2021
0.013
0.0098
ND
20211209-BS2
12/9/2022
0.019
0.020
ND
20230112-BS2
1/12/2023
0.0079
0.0045
0.039
MB-SW-BAS04-20201221
Basin 4
12/21/2020
0.11
NS
0.064
MB-SW-BAS04-
202010125
1/25/2021
0.05
0.042
0.032
MB-BAS04-20211102
11/2/2021
0.017
0.016
ND
MB-BAS4-20211227
12/27/2021
0.015
0.013
ND
20211209-BS4
12/9/2022
0.13
0.110
ND
20230112-BS4
1/12/2023
0.015
0.0071
0.462
NS= Not Sampled
mg/L= milligrams per liter
ju.g/L = micrograms per liter
Grey highlight = Above discharge limit
PAH = Polyaromatic Hydrocarbons
Total PAHs = Total calculated by adding up only detected results
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
21
-------
Figure 8. Basins 1, 2, and 4 Water Levels on January 12, 2023
4.2.2 Sediment Cap
The 2020 sediment analytical results collected from the sediment cap are below the ROD cleanup
standards (Table 6). An updated bathymetric survey that determines how much sediment deposition has
occurred in the slough post-construction of the sediment cap was last conducted in 2008. The 2008 post-
construction bathymetric survey of the capped area of the Old Mormon Slough identified some lowering
of the cap surface relative to its immediate post-construction configuration, assumed to be due to
continued compaction of soft underlying sediments.
22
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Sample ID
Sample
Date
2,3,7,8-
TCDD TEQ1
(pg/g)
PAHs (Organic Carbon
Basis)2 (mg/kg)
ROD Cleanup Standard
21
333
multiple sample locations
2010
0.39 to
13.74
10 to 48
MB-SED-01
6/16/2020
1.4
9
MB-SED-02
6/16/2020
1.3
74
MB-SED-03
6/16/2020
1.3
35
1 = 2,3,7,8-TCDD TEQ analysis by EPA Method 8290, TEQ calculation based on World Health Organization 2005 TEF, Dioxins, Furans, and
PCB Congeners. Reporting limits used for non-detect values.
2 = PAHs analysis using EPA Method 8270C SIM. Total PAHs are Organic Carbon Basis (calculated).
3 = EPA, 1999. Record of Decision, McCormick and Baxter Superfund Site, Stockton, California. March 31.
pg/g = picograms per gram
mg/kg = milligrams per kilogram
Although the sampling results indicate that the sediment cap is performing as intended, there have been
recent concerns about potential damage from debris due to trespassing. On February 17, 2023, a company
neighboring the Site notified EPA that a late-1990s Honda sedan was caught on fire near the slough.
Stockton Police Department told Ms. Kamran that they did not remove the car. However, when EPA
conducted a joint inspection on March 16, 2023, the car was not on-Site. Frequency of the bathymetric
survey and the soil cap survey may need to be reevaluated given the trespassing concerns.
4.2.3. Groundwater
The interim groundwater remedy has not been implemented and groundwater data has not been collected
since 2017. The primary chemicals of concern are naphthalene, acenaphthene, and PCP. Naphthalene,
acenaphthene have been principally tracked due to 1) their relative abundance in coal tar creosote and
relatively high mobility (naphthalene), 2) having the largest dissolved phase plumes (acenaphthene), and
3) their greatest relative magnitude of exceedance of the preliminary cleanup criteria. The previous Five-
Year review compared concentrations over a 13-year period (2004 to 2017) and concluded that the overall
concentrations and extent of the contamination has not significantly varied.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
23
-------
Legend
4C«0
Manrtonfig lAvtl Sampled
Monitoring Well Not Sailed
Naphthalene Contour (ug/L)
MAPL (calciiated u&rig MVS)
m CO Aqudard
| D Zone
| DEAqudud
.©s-ao
•"0 05;
250
500
I
1,000 Feet
I
McCormick and Baxter SuperfUrid Stt
Figure hM
Naphthalene in D Zone
Round 26 (April 2017)
Figure 9. Extent of Naphthalene in D-zone (2017)
24
Fourth Five-Year Review for McCormick arid Baxter Creosoting Company Superfund Site
-------
Legend
^ A« VMllO
«XC Concur* men luyil
(7rttit»B\ >r-to «' .u ». n|iW i
Monrtonna Well Sampled
Monitoring Wefl Not Sampled
Ac«n«phff)«n« Contour (i»3
-------
4.2.4. Sustainability
Climate change impacts that affect the Site may include the following: sea level rise, increased
precipitation and drought, changes in snowmelt, increases/decreases in groundwater levels, and
populations that are affected by disadvantaged community living situations.
Sea level rise continues to increase in Delta communities such as Stockton. Over the past 100 years, sea
levels have risen 5 to 8 inches and could rise an additional two feet by 2050. With increased flooding,
higher salinity concentrations in soil and groundwater within the San Joaquin Valley have the potential to
accelerate the degradation of monitoring wells via saltwater intrusion. In addition, changes in
groundwater levels may dramatically affect the region's infrastructure, including canals and waterways as
the Site is protected by a levee. The land will become more unstable due to prolonged droughts that
promote water filtration through the soil, soil cracking, erosion, and land subsidence.
Precipitation will become more intense by increasing the fraction of precipitation during the winter
months from 75% (present day) to 80% (by the end of the century) which translates into longer dry
seasons with 20% less precipitation on average. With more flooding and rain events, the storm water
detention tanks on-Site could potentially overflow into the forebay and increase the likelihood of
stormwater discharge exceedances.
S/fe Inspection
The inspection of the Site was conducted on March 16, 2023. In attendance were Sania Kamran, EPA,
Amir Mahjoor, DTSC, Andy Andrews and Ritchie Hodges Geosyntec, and Charity Meakes, USACE. The
purpose of the inspection was to assess the condition of the remedy and verify that the remedy is
operating as intended (Appendix G).
The participants counted 23 breaches in the Site fencing, including two sections that were down or
missing. All Site signage is faded and lacks identifying information that the Site is a Superfund Site. On-
Site camping and related debris continue to be an issue with at least 22 actively used camping areas in
addition to a dozen recreational vehicles, a semi-truck (without trailer), multiple tents, cars and lean-to's.
Three stripped cars and one burned out car were located within the Site property and the on-Site fire
hydrant had been opened. Dr. Mahjoor from DTSC stated that the city is planning to evict all the people
remaining on-Site and repair the fences.
There is regular cracking throughout the asphalt cap with vegetation growth occurring from small grasses
ranging from an eighth of an inch to larger weeds in approximately one-inch cracks. However, most of
the cracking is on the smaller side of the variation. Damage may be related to either driving or subsidence
due to several holes located throughout the cap.
The phytoremediation system appears to be missing one of the soil basins cubes that may have been
emptied and reused for indeterminate purposes at a campsite in addition to broken piping that has been
disassembled in many places. The phytoremediation study included 18 of the four-foot cubes for the
initial study, however, aerial photos from 2022 indicate two of the cubes appear to be no longer be on-
26
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Site. A second 55-gallon drum containing well cuttings that was located on Site in 2014 appears to be
missing as relayed by Dr. Mahjoor from DTSC.
The riprap cover to the slough and the small craft barrier did appear to be intact and functioning as
intended. All four stormwater basins were full or overflowing between the forebays and the main basins
due to recent rains. Ritchie Hodges from Geosyntec suggested that drainage from Basin 4 may be
partially blocked; however, the group was not able to observe whether this was true due to the remaining
standing water.
Overall, the Site appears to be lacking many security protocols in addition to missing equipment from the
phytoremediation study. While the small craft barrier appears to be functioning as intended, the
stormwater basins appear to still be clogged along with many monitoring wells lacking external
identification.
5. Technical Assessment
Question A: is the remedy functioning as intende the decision
documents?
The soil remedy is functioning as intended to prevent exposure to contaminated soil through excavation,
consolidation, and capping of contaminated soil. However, Site access has been compromised with
numerous breaches to the perimeter fence, missing locks on gates, damaged fence posts and encampments
throughout the Site property. As of April 2023, camps on-Site have been displaced by Stockton Code
Enforcement officers, and all vehicles on-Site have been towed.
Repairs to the asphalt cap and vegetation removal are completed annually by DTSC. However, additional
cracks and vegetation growing out of the cracks have been identified every year during the review period.
Damage to the asphalt cap may be due to either subsidence or possibly from cars driving on the Site
property. The asphalt cap may not be adequately designed or adequately constructed to prevent these
reoccurring maintenance issues of depressions and cap cracking. However, there has been no evidence of
exposure to contaminated soil under the cap.
The City of Stockton discharge limits for copper and dissolved copper and for total PAHs may have been
exceeded due to severe storms in early January of 2023 that flooded the forebays of Basins 1, 2, and 4.
The surface water-sediment remedy is currently functioning as intended, as the 2020 sediment sampling
analysis did not exceed the ROD standards for total PAHs and dioxins. Through capping of contaminated
sediment, there are no exposure routes via the surface water-sediment remedy for contamination of PAHs
and dioxins. The most recent bathymetric survey was conducted in 2008 as part of post-construction
activities and the bathymetric survey requires an update to confirm that the depth of the sediment cap is
adequate to prevent the migration of contaminants from Old Mormon Slough sediments into the surface
water.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
27
-------
The land use covenant for the Union Pacific Railroad parcel is not enforced as trespassers have been seen
on Site. As reported in the Site Inspection report, the fencing surrounding the Site has been breached
multiple times and the lapse of security allows trespassers to continue to use the Site. In addition, parcels
145-20-01, 145-20-14, 145-19-11 and 145-19-10 require an approved and implemented land use covenant
due to the trespassers recorded throughout the last five years. Physical access control measures (signs,
fences, and gates) are deteriorating and ineffective at preventing trespassers from gaining access to the
Site. The access restriction for the Old Mormon slough, the small boat intrusion, has been implemented.
Once the groundwater remedy is selected, EPA anticipates that the property will be redeveloped. DTSC
drafted a land use covenant for the remaining parcels that will include protecting the integrity of the
asphalt cap.
Questi ¦ mre assumptk icity C
medial Action Objectives Used at the Time of
Selection Si id?
Yes, exposure assumptions, toxicity data, cleanup levels and remedial action objectives used at the time
of remedy selection are still valid. No chemical-specific ARARs were used to select cleanup levels. The
to-be-considered factors used to identify cleanup levels in the sediments and soils have not substantially
changed (Appendix C).
Toxicity values for multiple contaminants have changed since the last Five-Year Review (Appendix D).
These changes do not affect the protectiveness of the remedies. The regional screening levels for
naphthalene and pentachlorophenol are more stringent than the soil cleanup levels but the cleanup levels
are still within EPA's acceptable risk range. The toxicity value for dioxin still indicates that the selected
soil cleanup level in the 1999 ROD is outside of EPA's acceptable risk range. Despite changes in toxicity
data for dioxin, the concentrations of dioxin in soil remaining after removal are within the range that EPA
considers protective. Sediment data collected in 2020 confirm that total PAH and dioxin concentrations
are below the ROD cleanup standards and the surface water-sediment remedy is functioning as intended.
The exposure pathways identified in the ROD for soil ingestion, soil particulate inhalation, and soil
dermal contact are still valid assumptions. However, recently the Site has been subject to frequent and
prolonged trespassing, possibly resulting in risk of exposure if no action is taken.
Other Infc ¦ . )uld
Call in estion the Protectiveness of y?
Yes, climate change and sustainability continue to be an issue at the Site. The persistent problems of
flooding, drought, extreme temperatures, and sea level rise remain leading problems. Additional
evaluation is needed regarding the stormwater permit and the capacity of the stormwater basins if
contamination continues to remain an issue with increased storm activity during the winter months. Sea
level rise has the potential to degrade the groundwater monitoring wells via saltwater intrusion. Since the
groundwater remedy has not been finalized, replacing any damaged or inaccessible groundwater
monitoring wells may be needed to ensure proper evaluation of contaminants.
28
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
6. Issues/Recommendations
Table 8. Issues and Recommendations Identified in the Five-Year Review
Issues ;ind Rcconiiiieiulitlioiis 1 dentilied in (lie l i\e-Ye:ir Rexiew:
OU(s): 2
Issue Category: Operations and Maintenance
Suitability and quality of the asphalt cap.
Issue: Due to the constant maintenance issues associated with the asphalt cap (major
cracking each year and depressions in the asphalt cap) the cap may not be suitable for
long-term maintenance of the remedy at the Site. The non-performance of the asphalt cap
may be due to the inadequacy of the design or construction, subsidence, or from
unauthorized people driving on the cap.
Recommendation: Investigate the quality and suitability of the asphalt cap to ensure that
the cap continues to protect human exposure to contaminated surface soils via direct
contact, ingestion, or inhalation. A cap expert is recommended to evaluate the
design/construction of the asphalt cap and to provide appropriate recommendations for the
cap.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party Responsible
Oversight Party
Milestone Date
No
Yes
EPA
EPA
9/1/2028
OU(s): 2
Issue Category: Site Access/Security
Issue: Physical access control measures (signs, fences, and gates) are deteriorating and
ineffective at preventing trespassers from gaining access to the Site.
Recommendation: Replace deteriorated or missing signs and repair breaches in the
fences and gates. Consider frequent Site inspections to discourage trespassing.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party Responsible
Oversight Party
Milestone Date
No
Yes
EPA
EPA
9/30/2024
OU(s): 2
Issue Category: Remedy Performance
City of Stockton Municipal Utilities District criteria limits
Issue: Discharge limits for copper, dissolved copper, and total PAHs have been exceeded
per the City of Stockton Municipal Utilities District criteria limits. The contaminants may
have been discharged off-Site due to multiple storms in January 2023.
Recommendation: Consider upgrading the stormwater system for greater capacity and
cleaning the outfall pipes of the stormwater basins. A source evaluation for the elevated
contaminants found in the stormwater basins is recommended to determine where the
sources may be coming from.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party Responsible
Oversight Party
Milestone Date
No
Yes
State
EPA
9/1/2028
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
29
-------
. Oth clings
In addition, the following are recommendations that improve management of operations and maintenance
to improve performance of the remedy and to promote sustainability but do not affect current and/or
future protectiveness and were identified during the Five-Year Review:
• Evaluate the stormwater piping that connects the forebays to the main Basin as there may be a
clog in several connections; and
• Protect the Site from fire hazards, as vegetation abatement is required for all parcels since dry
vegetation poses a fire hazard.
• Consider modifying the current O&M Plan to define the frequency and/or conditions when
sediment cap sampling, bathymetric survey, and asphalt cap inspection should be conducted.
7. Protectiveness Statement
Table 9. Protectiveness Statement
Protectiveness Statement(s)
Operable Unit:2 Protectiveness Determination:
(upland soils) Short-term Protective
Protectiveness Statement. The upland soils remedy currently protects human health and the environment because
the remedy prevents stormwater runoff of contaminated surface soils into adjacent surface waterbodies;
minimizes the migration of contaminants from subsurface soils and from the Old Mormon Slough; and prevents
human exposure to contaminated surface soils. However, for the remedy to be protective in the long-term, the
following actions need to be taken: the asphalt cap requires evaluation to ensure the quality and suitability of the
cap remains protective; the stormwater basins require evaluation for additional capacity; and physical security
controls need to be updated to ensure trespassers do not access the Site to ensure protectiveness.
Protectiveness Statement(s)
Operable Unit: 3 Protectiveness Determination:
(surface water-sediment) Protective
Protectiveness Statement. The surface water-sediment remedy is protective of human health and the
environment. All exposure pathways have been eliminated or controlled through the sand cap, the small boat
intrusion barrier, and the safety zone established by the US Coast Guard.
30
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
8. Next Review
The next Five-Year Review report for the McCormick and Baxter Creosoting Company Superfund Site is
required five years from the completion date of this review.
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
31
-------
Appendix A: List of Documents Reviewed
California's Fourth Climate Change Assessment. 2023. Accessed December 13, 2022;
https://climateassessment.ca.gov.
DTSC (California Department of Toxic Substances Control). 2020. Operations and Maintenance Work
Plan for the McCormick and Baxter Site, prepared by Geosyntec Consultants, Stockton,
California. February 25.
DTSC. 2021. 2020 Annual Operation and Maintenance Report, McCormick and Baxter Creosoting
Company Superfund Site, prepared by Geosyntec Consultants, Stockton, California. March 1.
DTCS. 2022. 2021 Annual Operation and Maintenance Report, McCormick and Baxter Creosoting
Company Superfund Site, prepared by Geosyntec Consultants, Stockton, California. April 6.
DTSC. 2022. Storm water Discharge Criteria, 2021 Annual Operations and Maintenance Report
Memorandum, McCormick and Baxter Creosoting Company Superfund Site, prepared by
Sacramento Geological Services Unit, Stockton, California. June 15.
DTSC. 2022. Site Visit Report, McCormick and Baxter Creosoting Company Superfund Site, Stockton,
California. August 25.
DTSC. 2023. 2022 Annual Operation and Maintenance Report, McCormick and Baxter Creosoting
Company Superfund Site, prepared by Geosyntec Consultants, Stockton, California. March 16.
EPA (United States Environmental Protection Agency). 1999. Record of Decision, McCormick and
Baxter Creosoting Company, Operable Units 1 and 3, Stockton, California. March 31.
EPA. 2005. Explanation of Significant Differences, McCormick and Baxter Creosoting Company
Superfund Site, Operable Unit 3, Stockton, California. September 27.
EPA. 2021. Field Sampling Plan, Groundwater Monitoring (Draft), McCormick and Baxter Creosoting
Company Superfund Site, Stockton, California. August 17.
EPA.2022. McCormick and Baxter Site Inspection Report, McCormick and Baxter Creosoting Company
Superfund Site, Stockton, California. October 19.
Landmeyer JE, Rock S, Freeman JL, et al. Phytoremediation of slightly brackish, polycyclic aromatic
hydrocarbon-contaminated groundwater from 250 ft below land surface: A pilot-scale study using
salt-tolerant, endophyte-enhanced hybrid poplar trees at a Superfund Site in Central Valley of
California, April-November 2019. Remediation. 2020;1-17. https://doi.org/10.1002/rem.21664
U.S. Army Corps of Engineers, Seattle District, 2018. Third Five-Year Review for McCormick and
Baxter Creosoting Company Superfund Site, Stockton, California. September 24.
USACE, Seattle District, 2020. McCormick and Baxter Creosoting Company Superfund Site RPT Report,
prepared by Environmental International Corporation, Stockton, California. December 18.
RiskFactor.com. 2023. Accessed December 13, 2022; https://riskfactor.com
32
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Appendix B: Site Chronology
Event
Date
McCormick and Baxter Creosoting Company was in operation at the Site.
1946-1991
A fish kill in New Mormon Slough and Stockton Deepwater Channel was caused by PCP-
contaminated stormwater runoff from the Site.
1977
Regional Water Quality Control Board issued a Cleanup and Abatement Order.
1978
McCormick and Baxter Creosoting Company entered into an agreement with DTSC and
Regional Water Quality Control Board to investigate on-Site contamination.
1984
EPA Site inspection, preliminary assessment and hazard ranking were conducted.
1984
An EPA Site investigation report was conducted.
1990
McCormick and Baxter Creosoting Company conducted a baseline (human health) risk
assessment.
1990
McCormick and Baxter Creosoting Company filed for bankruptcy.
1991
McCormick and Baxter Creosoting Company ceased on-Site wood treating operations.
1992
EPA finalized the Site's listing on the National Priority List.
1992
Removal of industrial chemicals, sludge, tanks, demolition and removal of most buildings
was completed.
1992-1997
Combined Remedial Investigations/Feasibility Study activities were conducted.
1992-1999
A sheet-pile wall installed along Old Mormon Slough shoreline to control seeps from oily
waste ponds area.
1996
Soil and oily waste were excavated from oily waste ponds area and transferred to a lined
on-Site disposal area. The oily waste pond area was backfilled with clean soil; a lined
disposal area and main processing area were capped with asphalt.
1997
The Proposed Plan was issued.
1998
The Record of Decision (final remedies for soil and sediment and interim remedy for
groundwater) was signed.
1999
Remedial design of sediment remedy was developed.
1999-2002
Phase I of the sediment remedy was completed (bank stabilization).
2003
An Explanation of Significant Differences was issued.
2005
Remedial design/remedial action negotiations were conducted for the soil remedy.
2000-2006
Vessels were removed from the capping area within Old Mormon Slough
2006
The Phase II sediment remedy was completed (sediment capping).
2006
A Consent Decree for soil remedial design/remedial action was issued.
2007
The first Five Year Review was completed
2008
Post-construction bathymetric survey of the cap was conducted.
2008
Remedial design for the soils remedy was developed.
2008
Soil remedy excavation, confirmation sampling, and cap installation were undertaken.
2009-2011
Sediment remedy cap monitoring was conducted.
2010
Replacement of log boom with Whisper Wave Small Craft Intrusion Barrier.
2013
The second Five Year Review was completed.
2013
US Coast Guard establishes a Safety Zone in the capped portion of the slough.
2013
Transfer of soil remedy and sediment remedy to California DTSC for operation and
maintenance.
2015
Fourth Five-Year Review for McCormack and Baxter Creosoting Company Superfund Site 33
-------
Event
Date
The third Five Year Review was completed.
September 2018
California DTSC updates the Operations and Maintenance Report Work Plan
February 25, 2020
EPA conducts a Pilot Study for Phytoremediation for the groundwater remedy
April-November 2020
California DTSC submits 2020 Operations and Maintenance Report
March 1,2021
California DTSC submits 2021 Operations and Maintenance Report
April 6,2022
Sacramento Geological Services Unit submits the Stormwater Discharge Memorandum to
California DTSC
June 15,2022
California DTSC conducts a Site visit
August 25, 2022
EPA conducts a Site visit
October 19,2022
34
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Appendix C: Applicable or Relevant and
Appropriate Requirements
Assessment
Section 121 (d)(2)(A) of Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) specifies that Superfund remedial actions must meet any Federal standards, requirements,
criteria, or limitations that are determined to be legally applicable or relevant and appropriate
requirements (ARARs). ARARs are those standards, criteria, or limitations promulgated under Federal or
State law that specifically address a hazardous substance, pollutant, contaminant, remedial action,
location, or other circumstance at a CERCLA Site.
When ARARs are not fully protective, EPA may implement other federal or state policies, guidelines, or
proposed rules capable of reducing the risks posed by a Site. The toxicity standards, while not legally
binding since they have not been promulgated, may be used to achieve an unacceptable level of risk.
The ROD cleanup standards for soils and sediments are toxicity-based, not ARAR based and are
evaluated in the Toxicity Analysis (Appendix E). The cleanup standards consider risks associated with
dermal contact, ingestion, and inhalation of contaminated materials. Therefore, there are no regulated soil
cleanup values against which cleanup levels chosen in the ROD can be compared.
Construction is completed on both the surface water-sediment remedies and the soil remedies, and no new
information has come to light in this review to suggest changes to any other ARARs listed below.
Accordingly, the legal analyses preformed at the time of the ROD and ESD are no longer pertinent due to
the phase of the remedies. There have been no revisions to laws and regulations that affect the
protectiveness of the remedy.
There have been no changes in the following action- or location-specific ARARs, and therefore, there
have been no changes affecting the protectiveness:
• Endangered Species Act of 1973 (16 U.S.C. section 1531, et seq.)
• 22 CCR Subpart N
• 22 CCR Division 4.5, Chapter 14
• 22 CCR 66264.310(a)(l)-(6)
• 22 CCR 66264.310(b)(1), (4) and (5)
• 62 Federal Register 25998
• 40 CFR Part 50
• CCR, Title 23, Chapter 15, Article 4
• State Board Resolution 68-16
• Construction Activity, Order No. 92-08-DWQ
Fourth Five-Year Review for McCormack and Baxter Creosoting Company Superfund Site
35
-------
• Rivers and Harbors Act (33 USC, Section 403, Section 10)
• Clean Water Act (33 USC Section 1344, Section 404
• 42 USC Section 6921 et seq.
36
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Appendix D: Toxicity Assessment
A human health risk assessment was completed for the Site as part of the remedial investigation in
July 1998. The baseline risk assessment identified exposure pathways at the Site as exposure to on-
Site workers from soil by way of ingestion, inhalation, and dermal contact. Human ingestion of fish
tissue from contaminated waters was also a concern. Soil cleanup levels were based on the 1999
Region 9 Preliminary Remediation Goals for industrial land-use (Table E-l). Sediment contaminant
concentrations exceeded ecological levels of concern (Table E-2).
EPA adopted Regional Screening Levels as soil and sediment cleanup levels. EPA's Integrated Risk
Information System updates toxicity values used by EPA in risk assessment when newer scientific
information becomes available, and the most recent update available used for this analysis was the
November 2022 update.
Table E-1. Summary of Soil Toxicity Changes
(lu-lllk;il
Soil ('k-;inii|>
Ia-m-i (ni^/km
IS:isis liir ( k"iiiii|) l.i-u-1
Ciirmil Imliisirhil
RSI. (m»/k»)
i- = liiiuir
n = miiu;iiuiT
RSI.s Mun-
ii r 1.1-SS
Si ri nm.nl
1 ll;i 11
(k-;illll|>
l.i-M-ls".'
Benzo(a)pyrene
3.6
1999 EPA Region 9
Preliminary Remediation
Goals (PRGs; currently
known as regional screening
levels or (RSLs) adjusted to a
10"5 risk for industrial land
use.
2.1 c
More
stringent
Acenaphthene
1100
45000 n
Less
stringent
Anthracene
57
230000 n
Less
stringent
Fluorene
900
30000 n
Less
stringent
Naphthalene
190
86 c
More
stringent
Pyrene
1000
23000 n
Less
stringent
Pentachlorophenol
150
40 c
More
stringent
2, 3, 7, 8-TCDD (Dioxin)
1 ug/kg (dry
weight, organic
carbon
normalized)
0.22 ug/kg c (Cal
Mod 0.22-0.7
ug/kg)
More
stringent
Arsenic
30
480 ca 30 c (Cal
Mod 4.2 n)
Less
stringent
Notes:
c = cancer, n = noncancer, Cal Mod= California modified RSL (November 2022), RSL = Regional Screening Level
(November 2022)
To evaluate the protectiveness of the cleanup levels for this Five-Year Review, the cleanup levels were
compared to EPA's current regional screening levels. The regional screening levels addressing the risk
Fourth Five-Year Review for McCormack and Baxter Creosoting Company Superfund Site
37
-------
of developing cancer are chemical-specific concentrations for individual contaminants that correspond
to an excess cancer risk level of 5xl0"5 (or a hazard quotient of 1 for non-carcinogens), and they have
been developed for a variety of exposure scenarios (i.e., residential, commercial/industrial). Regional
screening levels are not de facto cleanup standards for a Superfund Site but provide a good indication
of whether actions may be needed to address potential human health exposures. The EPA acceptable
risk range is between lxlO"6 and lxlO"4. Remedial goals that fall within this risk range were
determined to be acceptable from a risk standpoint. The non-cancer regional screening levels
correspond to a hazard quotient of 1.
There have been changes to the regional screening levels for chemicals of concern at the Site. The
regional screening levels for acenaphthene, fluorene, and pyrene have not undergone any significant
revisions that would affect protectiveness. Revisions to regional screening level for benzo(a)pyrene,
pentachlorophenol, naphthalene, and dioxins indicate a higher cancer risk from exposure than
previously considered. Based on the current regional screening levels, the excess cancer risk
associated for benzo(a)pyrene, pentachlorophenol and naphthalene cleanup level is now 4 x 10"5 and
the excess cancer risk associated with dioxin cleanup level is now 5 x 10"5 cancer. All excess risk
values are within EPA's acceptable excess cancer risk range.
The basis for selecting the cleanup level for arsenic has not changed. However, the State of California
issued a new non-cancer screening level in 2018, which would result in a Hazard Index of 8, well
above EPA's Hazard Index cutoff of 1. Because the remedy consolidated all the contamination into the
higher contaminated area and cap with clean soil, the direct exposure pathway has been eliminated.
Ecological Review
The Ecological Risk Assessment concluded that while sediment contamination was greater in Old
Mormon Slough than in surrounding areas, biological effects were localized. Potential risk to receptor
species were attributed to the presence of total PAHs and dioxin, and possibly PCP, in surface
sediments. In general, metals were not found to be a risk factor to any of the assessment endpoints.
The results for PCP were less certain, but PCP was estimated to have a potential impact to both fish
and benthic animals. The total PAHs posed a risk to all assessment endpoints; threshold limits for total
PAHs were exceeded principally for fish and benthic fauna. Dioxin had little effect on the assessment
endpoints but was estimated to be a potential low risk to bird and fish reproduction and health.
The selected sediment remedy consisted of in-situ capping of contaminated Old Mormon Slough
sediments to isolate areas of principal threat waste (approximately three-fourths of the slough) by
blanketing them with clean fine sand with a minimum depth of 2 feet. The cap materials were armored
with riprap and a gravel filter layer to prevent erosion.
38
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Table E-2. Summary of Sediment Toxicity Changes {Old IVlorrnon Slough)
Chemical
Sediment Cleanup Level
Basis for Cleanup Level
Total PAHs
333 milligrams per kilogram
(dry weight, organic carbon
normalized)
Site-Specific risk-based Maximum Sediment
Concentrations developed in the Ecological Risk
Assessment
2, 3, 7, 8-TCDD
(Dioxin)
21 nanograms per kilogram
toxicity equivalence
Because Old Mormon Slough is a dead-end slough that is poorly flushed by river flow or tidal action,
and due to the presence of a boom which prevents boat access and any concomitant sediment
disturbance, the rate of any sediment transport out of the slough is expected to be very low. This
would likely result in burial and stabilization of the contamination in place, rather than transporting it
outside the Old Mormon Slough to other areas.
For total PAHs, there is more recent information that shows toxicity to juvenile fish at lower
concentrations than the cleanup level. But ambient total PAHs in an industrial harbor such as the Port
of Stockton are above these lower concentrations, therefore any new cleanup level for total PAHs
would be comparable to the existing cleanup level.
Fourth Five-Year Review for McCormack and Baxter Creosoting Company Superfund Site
39
-------
Appendix E: Public Notice
? Q i
vS'!
EPA WANTS TO HEAR FROM YOU ABOUT THE
MCCORMICK AND BAXTER SUPERFUND SITE CLEANUP
The U.S. Environmental Protection Agency (EPA) has started a review of the cleanup plan for the McCormick and Baxter
Creosoting Company Superfund site. The site is in Stockton, Calif. This review will show if the cleanup plan is working as EPA
intended.
Federal law requires EPA to review its cleanup plans every five years if:
- a cleanup takes more than five years to complete; or
- hazardous waste is still on-site.
EPA did the last review in 2018 and found the cleanup plan was working as intended.
What is included in the review?
• An inspection of the site and technologies used for the cleanup
• A review of site data and maintenance records
• A review of any new laws or requirements that could affect the cleanup
EPA would like to hear from you!
We would like to interview community members about how you think the site cleanup is going. If you want to learn more
about the site and/or be interviewed, please call Ms. Cynthia Wetmore before May 30, 2023:
• Cynthia Wetmore, EPA Project Manager: (415) 972-3059 or
wetmore.cvnthia@eoa.aov
Where can I learn more?
Visit EPA's webpage at epa.gov/superfund/mccormick-baxter for more information. To read the previous Five-Year Review
reports, please click on the "Site Documents and Data Links" section. EPA has also set up an information repository with paper
copies of the site's Administrative Record (which includes key documents and reports for the cleanup) at:
Stockton-San Joaquin County
Cesar Chavez Central Library
605 North El Dorado Street
Stockton. CA. 95202
(209) 937-8221
Please call for current hours of operation
and
Superfund Record Center
75 Hawthorne Street, Room 3100
San Francisco, CA 94105
Phone: (415)947-8717
Email: R9records@eoa.aov
Hours: 8:00 a.m.-5:00 p.m., Mon.-Fri.
Please call for current hours of operation
EPA will complete the Five-Year Review report no later than September 30. 2023 When complete. EPA will post a
copy on the site's webpage and send a copy to the site information repository listed above.
Background
The McCormick & Baxter Creosoting Co. site is a 29-acre former wood preserving facility. It is located at 1214 West
Washington St. in Stockton, Calif. From 1942 to 1990, utility pole and railroad tie treatment activities on site contaminated
the soil and groundwater. After building the site's soil, sediment, and surface water remedy (cleanup plan) in 2006, operation
and maintenance activities for the remedy started (and are ongoing). The groundwater has not been cleaned up yet. EPA is
currently testing several groundwater cleanup options to see which is most effective.
CNSB#3650042
40
Fourth Five-Year Review for McCormick and Baxter Creosoting Company Superfund Site
-------
Appendix F: Interview Forms
Five-Year Review Interview Record
Site:
McCormick and Baxter Superfund Site
EPA ID No:
CAD009106527
Interview Questionnaire
Date:
(Fill in the components below, one line per person if multiple persons are providing responses)
Name
Organization
Title
Telephone
Email
Amir Mahioor
DISC
Engineering Geologist
(916) 255-374?
Arriirsasan.rriahioorlgdtsc.ca.gov
(Record responses to the guestions below)
1) What is your overall impression of the project?
The soil cap is functioning as expected. The stormwater management system of the Site does not have sufficient capacity to
manage stormwater from a significant storm event. During the last major storm in early January 2023, all basins filled beyond their
capacity. Much of Subarea X was flooded due to poor grading. During the storm event, the soil supporting the asphalt and its
concrete edge were compromised. The asphalt and the concrete edge caved or collapsed where the supporting soil was
compromised. Seeping water through the existing cracks and edges, saturated and loosen the asphalt foundation. The seepage led
to the expansion of the existing cracks and the formation of potholes, fatigue cracks, and lateral cracks on the cap, A large pond
formed in Subarea X due to poor grading. Trespassing and homeless encampment are major health and safety concerns for DTSC
staff and DTSC contractors performing work at the Site, The accumulation of dry vegetation in Union Pacific (UP) owned parcels of
Subarea X poses a fire hazard, UP refuses to carry out routine vegetation abatement at their parcels,
2) Is the remedy functioning as expected? How well is the remedy performing?
The remedy is functioning as expected with the issues noted in the previous answer,
3) What does the monitoring data show? Are there any trends that show contaminant levels are decreasing?
Referring to the 2020 ANNUAL OPERATION AND MAINTENANCE REPORT (AOMR) prepared by Geosyntec analysis of samples
collected from the sediment cap does not show any contaminants above cleanup levels. According to 2020 and 2021 AOIVIRs
stormwater analysis, copper was the only laboratory analytical result above the discharge limits in basins 1, 2, and 4,
4) Is the frequency of O&M visits sufficient to address the fence damage frequency and issues and prevent trespassing? Is there
adequate signage on-Site?
Inspections of the soil cap, fences, and general condition of the Site are performed annually, and repairs are carried out based on
the results of Site inspections. The asphalt cap is repeated each year for the last two years. Damage to the fence by trespassers is
an ongoing issue, On-Site signages are not adequate. During my last visit in November 2020, only flood zone warning signs were
observed at the Site, Most of the signs were faded and difficult to read. No fish consumption advisory sign was noted around the Old
Mormon Slough, No long-term exposure and no trespassing signage were observed at the Site,
5) Have the stormwater blockages been addressed?
The issue with the stormwater blockages was addressed but the forebays and the main basins still flooded during the latest major
storm event,
6) Have the holes in the cap been repaired?
The asphalt cap has been repeated each year for the past two years,
7) Have there been changes to the NPDES permit due to identified elevated copper levels in the stormwater discharge found in the
2020 and 2021 Site visits?
To address the issue, the DTSC contractor (Geosyntec) will prepare a work plan and investigate potential copper sources.
8) When was the last bathymetric survey conducted? What did the data show about the sediment cap? Is there a need to complete
an additional bathymetric survey?
The last bathymetric survey was conducted in 2008,
9) Are you aware of any changes in the Federal/State/County/Local Laws and regulations that may impact the protectiveness of the
Trip Report
McCormick and Baxter FYR
41
-------
remedy?
No
10) Do you have any comments, suggestions, or recommendations regarding the project?
Site safety is a major concern for staff working at the Site and trespassers. Some of the ways to improve Site safety include more
frequent inspections and repairs to fences and posting warning signs around the Site, The Site's stormwater management system
failed to manage the volume of stormwater during the last large storm event and flooding occurred at several locations on the Site, It
is recommended that the stormwater management system be upgraded. The DEP advised the DTSC of a prospective purchaser for
the Site, The prospective purchaser buyer should be informed that the soil cap is not designed to support any load and use of the
property would require redesigning the soil cap to support activities on the Site, Vegetation at the UP-owned parcels of the Site
imposes fire hazard during the dry season.
Five-Year Review Interview Record
Site:
McCormick and Baxter Superfund Site
EPA ID No:
CAD009106527
Interview Questionnaire
Date: March 7, 2023
(Fill in the components below, one line per person if multiple persons are providing responses)
Name
Organization
Title
Telephone
Email
James Stellmach
USACE-SPK-EDE-E
EnvironmentaI engIneer
916-804-9556
James,p.stelliTiachQusace.arrriy.mil
(Record responses to the guestions below)
1) What is your overall impression of the project?
The project is in good shape, except for Site security, with multiple holes in the perimeter fence, and unhoused individuals having
access to the property,
2) Is the remedy functioning as expected? How well is the remedy performing?
As far as I am aware, the sediment cap remedy is performing as expected, as is the soil cap remedy (there is some surficial
damage, but I am not aware if this impacts the remedy),
3) When was the last groundwater sampling event? What does the monitoring data show? Are there any trends that show
contaminant levels are decreasing?
2017, I do not closely follow the results or trends,
4) Is the frequency of O&M visits sufficient to address the fence damage frequency and issues and prevent trespassing? Is there
adequate signage on-Site?
The O&M frequency is not sufficient to prevent fence damage and trespassing. The number of signs was sufficient as of 2017, but
signs have been sun-damaged and also vandalized, and possibly removed in some locations. Daily O&M security of some
frequency (if not full-time, then multiple checks throughout a 24-hour period) may be needed to ensure sufficient Site security O&M.
5) Have the stormwater blockages been addressed?
I am not aware of this issue,
6) Have the holes in the cap been repaired?
I have only cursory awareness of this issue,
7) Are you aware of any changes in the Federal/State/County/Local Laws and regulations that may impact the protectiveness of the
remedy?
No,
8) Do you have any comments, suggestions, or recommendations regarding the project?
Fence repairs and some form of consistent Site security O&M should be implemented in order to maintain security of the Site,
-------
Appendix G: Site Inspection Report and
Photos
Trip Report
McCormick and Baxter Superfund Site - Stockton, San Joaquin County, CA
1. INTRODUCTION
a. Date of Visit: March 16, 2023
b. Location: Stockton, CA
c. Purpose: A Site visit was conducted to visually inspect and document the conditions of the
remedy, the Site, and the surrounding area for inclusion into the Five-Year Review Report.
d. Participants:
NAME ORGANIZATION
Charity Meakes USACE-SPK, Senior Environmental Engineer
Sania Kamran EPA, RPM
Amir Mahjoor Ph. D. DTSC, Engineering Geologist
Andy Andrews Geosyntec, Senior Environmental Engineer
Ritchie Hodges Geosyntec, Environmental Engineer
2. SUMMARY
A Site visit was completed at the McCormick and Baxter Superfund Site on March 16, 2023, as
part of the Five-Year Review. The weather was sunny and in the low 60s. The Site visit occurred
from approximately 12:45 to 14:45, which included a walk through the Site, as well as visits to
some off-Site wells.
3. DISCUSSION
Asphalt cap
There is regular cracking throughout the asphalt cap with vegetation growth occurring, from
small grasses in -1/8" cracks to large weeds in ~1" cracks (see photos 5, 7, 9, 14 and 20 for
examples). The majority of cracking is on the smaller side of that variation, with some areas
being larger, particularly in the NW corner of the Site (see photo 14). There is an area perhaps
20' in diameter of subsidence or lack of drainage in the SW side of the asphalt cap, and another
perhaps 50'x 20' area with lack of drainage just North of Detention basin 2 in the asphalt cap (in
photo 7). There is an area perhaps 12' long on the SW side with a broken curb on the edge of the
cap (see photo 13). There are several areas in the eastern soil portion of the Site that have been
damaged by driving or perhaps subsidence, such as on the Eastern edge, as seen in pictures 1 and
10.
Property fencing and signage.
It appears that there are 23 breaches in the Site fencing, including 2 sections that were
down/missing in the NE corner of the Site that are several hundred feet long each (see photo 10).
Trip Report
McCormick and Baxter FYR
43
-------
There are small holes in or near all the detention basin gates (see photo 11 for example), and 17
other person- to vehicle-sized holes in the fence around the Site, including large damage to both
access gates to the Site (see photos 12, 13, and 16, for examples).
The Site signage was universally faded and/or lacking (see photo 3 for typical detention basin
sign). There did not appear to be any signage identifying the Site as a Superfund Site. No signage
appeared to have any language other than English.
On-Site camping and debris
There were many areas of the Site that were actively being used, or perhaps had been used, for
camping by unhoused people, including approximately a dozen RVs, a semi-truck (without
trailer), multiple tents, cars and lean-to's. There are possibly 22 actively used camping areas, as
well as additional areas of debris or possibly abandoned camping areas. There were also three
stripped vehicles (a silver Toyota Prius, a blue sedan-like a Honda Accord, and a white SUV-like
a Ford Expedition) and one burned out vehicle on the Site (appeared to be another SUV-like a
Jeep Cherokee). The camping Sites are spread throughout the McCormick and Baxter Site, along
eveiy border fence, however the largest grouping is in the N and NE corner of the Site. See
photos 1, 2, 5, 8, 10, 16 and 18, for examples. The on-Site fire hydrant had been opened (see
photo 9).
At the time of the Site visit, very few of the people living on-Site were visible, but there were
many friendly roaming dogs, the Stockton Police, Stockton Code enforcement personnel, and a
proselytizer on-Site. According to Dr. Mahjoor from DTSC, the city said they were planning to
evict all the people from the Site, clean it up, and repair the fences.
Phytoremediation Study system
There is one large (-3,000-gallon tank), and 16 approximately 4' soil basin cubes that were used
in the phytoremediation study currently on Site. Fifteen of the cubes still appear in their original
location, mostly full of soil and vegetation, with their insulation degrading (see photos 4 and 7).
The piping for the system is broken and disassembled in many spots, including the tank having
an open port near the bottom. One of the ~4' soil basin cubes appears to have been emptied and
reused for indeterminate purposes at a campsite on the NW portion of the M&B Site (see photo
5). There were 18 of the ~4' cubes used in the phytoremediation study and visible on aerials in
2022; two of these no longer appear to be on-Site. There is no obvious area where the soil was
emptied, however due to the size and weight of the containers, it may be safe to assume that they
were emptied at the location of the study. There was also a vertical pipe extending perhaps 8-10
feet tall near the system, visible in photo 4.
View of Phytoremediation System with 18 soil basins in
March 2022 on Google Earth
-------
There is also one metal 55-gallon drum on-Site near the main gate (photo 6) holding IDW soil
from 2014 that had been set aside for the phytoremediation study. Dr. Mahjoor from DTSC
mentioned that another metal drum used to be on-Site next to the existing one, but we did not see
the second drum on-Site.
Riprap cover to slough, small craft barrier, and Sediment Cap
The riprap cover, sheet piling, and small craft barrier did appear to be intact and functioning as
intended. There was debris scattered around the riprap inside the slough-side fencing.
During our Site visit there was no indication of dumping of large items into the slough, however
there were a couple large holes in the slough fence, through which it would have been possible
that items large enough to potentially damage the sediment cap (such as a vehicle) could have
entered the slough. Google satellite imagery from March 2022 (the latest currently available)
also showed no indication of large items that may have gotten into the slough, however there
were also slightly fewer campsites on-Site at that time, and the full phytoremediation system was
still intact in that image as well. During our Site visit on March 16, 2023, one of the vehicles
shown burning on-Site in pictures sent to the EPA March 20, 2023, from nearby business is no
longer visible on-Site. It may be worthwhile in the future five-year review to do a backwards
look through google earth images to make sure there is no evidence of large items visible in the
slough water, and also to reach out to the city of Stockton to see if they know if whether that
vehicle (which appeared to be a burned 4 door silver or white sedan), was towed off-Site.
Stormwater basins
All four stormwater basins were full or even overflowing between the forebays and main basins
due to recent rains. Basins 2 and 4 had water covering the berm between the two basins (see
photo 8, for example). Ritchie Hodges from Geosyntec, which has been DTSC's contractor on
the Site in recent years, suggested that drainage from basin 4 may be partially blocked, but with
all the water, the site inspection participants were not able to visually identify any specific
concerns. Fencing around all basins was generally good, with the exception of a small hole near
or in the gate at all four basins (see Photo 11, for example). All signage was faded (see Photo 3,
for example). Monitoring well A-6 on the south side near basin 2 appears to have been damaged
and flooded with the stormwater, although site inspection participants were not able to get inside
fencing for a closer look. The DSW-7 wells in detention basin 3 also appeared to be flooded (see
photo 18).
Monitoring Wells
Many monitoring wells lack external identification. While some wells appear to be secure and
undamaged, there are several wells that are damaged, including A-10, which has a cracked base,
or have open access, including DSW-5B. Others appear to be both damaged and open, including
one of the DSW-1 wells (see photo 15). However, the exact wells were indeterminate due to lack
of external identification. Additionally, some of the more easily accessible off-Site wells were
inspected during the Site visit, and those appeared secured and undamaged (see photo 17 for
example). In a separate email, James Stellmach of the USACE Sacramento office recently noted
Trip Report
McCormick and Baxter FYR
45
-------
that their team were not able to locate/access the following off-Site wells: OFS-5 wells and OS-6
wells appear to have been paved over; a couple of the OS-1 wells were buried; and MW-3E was
inaccessible due to brambles overgrowth.
4. ACTIONS
The USACE will incorporate information obtained from the Site visit into the Five-Year Review
report.
Charity Meakes
Senior Environmental Engineer
Sacramento District
-------
Photo
Caption
View of Site from
east on W.
Washington St.
looking West.
Typical areas of
campsites and
debris.
View of Site from
east on W.
Washington St.
looking North-
West towards
detention basm 4.
Typical areas of
campsites and
debris.
-------
Det Basin 1 -
Typical Faded Sign
on all detention
basin gates.
Main area with
leftover phyto-
remediation study
equipment.
Typical debris.
-------
One phyto-
remediation tank
(previously filled
with soil and tree
saplings) spotted
being improperly
reused on northern
side of Site.
Near main gate 011
south side of Site.
One of two leftover
drums of well
cuttings from
monitoring well
construction in
2014. During a Site
visit m December
2022, the second
drum was still
present. It appears
that someone
disposed of the
contents of the
second dram right
behind it, in the
vegetated area,
visible on the left
side of this photo.
The location of the
second dram is
unknown.
Trip Report
McCormick and Baxter FYR 49
-------
7.
;r:±2;--r •• •
v
Near Basin 2
looking East.
Typical Site debris,
with Phyto-
remediation system
in mid-
background, and
area of subsidence/
ponding on cap.
with typical
vegetation growth
in cracks on cap in
foreground.
Detention basin 2,
looking East.
Forebay and Main
basin merged due
to recent rains.
MW (A-6, likely)
on South side of
water (right side of
photo) appears it
had been
submerged.
2 stripped vehicles
to left, debris
-------
One of two very
large areas of
missing fence in
NE corner of Site,
and typical damage
to soil area in NE
corner of Site.
On-Site fire
hydrant, opened.
Typical asphalt cap
cracking with
vegetation.
Trip Report
McCormick and Baxter FYR 51
-------
Detention Basin 2.
Typical small hole
in fence at all
detention basins.
Main entrance gate
(south side of site)
bent in half and
typical debris and
cap
cracking/vegetation
growth in
foreground.
-------
Trip Report
McCormick and Baxter FYR
53
-------
15.
Monitoring well
near phyto-
remediation system
(possibly one of
the DSW-1
wells?).
On NW part of
Site, looking NW -
One of multiple
burned out and/or
stripped vehicles
on Site, with a
vehicle sized large
hole in fence to
right.
-------
Off-Site GS-4
wells on W.
Sonora St., with
nearby campsite.
Detention basin 3.
DSW-7 wells
appear to be under
water.
Trip Report
McCormick and Baxter FYR
55
-------
Inside slough
fence, looking east.
Large hole/access
portal through
fence visible on
right.
Typical debris.
------- |