Technical Memo: Cone penetration testing & discrete · PDF fileTechnical Memorandum Cone Penetration Testing and Discrete-Depth Groundwater Results Pemaco Superfund Site, Maywood,

317 E. Main Street Ventura, CA 93001

Tel: (805) 585-2110 Fax: (805) 585-2111

TECHNICAL MEMORANDUM Date: August 4, 2015

Prepared For: Rose Marie Caraway, Remedial Project Manager/Environmental Scientist U.S. Environmental Protection Agency 75 Hawthorne Street, SFD 7-2 San Francisco, California 94105

Prepared By: John Wingate, P.E., Project Manager, OTIE

Nova Clite, P.G. Hydrogeologist, OTIE

Lucas Budny, P.G. Project Geologist, OTIE

Re: Cone Penetration Testing and Discrete-Depth Groundwater Sampling Results

1.0 INTRODUCTION Oneida Total Integrated Enterprises, LLC. (OTIE) prepared this Technical Memorandum to document the results of Cone Penetration Testing (CPT) and discrete-depth groundwater sampling in an area lying north and west of the Pemaco Superfund Site (The Site) located in Maywood, California, as shown in Figure 1.

The CPT and discrete-depth groundwater sampling fieldwork was conducted from December 1 to December 17, 2014. The objective of the work is to facilitate an understanding of trichloroethene (TCE) concentrations to the north of the Site, upgradient of Monitoring Well (MW)-01-80, and in the western portion of the Site, north of MW-12-90.

Ten groundwater samples were collected via CPT at approximately the same time as the December semiannual groundwater-monitoring event. The resulting combined data set, discussed herein, has expanded the understanding of existing contaminant plumes and identified data gaps in ground water gradient and plume boundary conditions.

The United States Environmental Protection Agency (EPA) is currently implementing the Long Term Response Action (LTRA) at the Pemaco Superfund Site. OTIE performed the CPT work for the EPA under contract by the United States Army Corps of Engineers, Los Angeles District Contract Number W912PL 13-D-0017, Task Order 0002.

1.1. TCE CONCENTRATIONS IN MW-01-80 AND MW-12-90 TCE concentrations in MW-01-80 (northern portion of the Site) and MW-12-90 (west of the Site on Alamo Ave.) were historically non-detect or below the site-specific remediation level (SSRL) of 5 micrograms per liter (µg/L). However, more recent data shows that TCE concentrations increased and then peaked; in 2011 for MW-01-80 (2,100 µg/L) and then in 2013 for MW-12-90 (68 µg/L). Graphs 1 and 2 depict the TCE concentration trend over time for MW-01-80 and MW-12-90, respectively.

OTIE Page 1 of 1

SEMS-RM DOCID # 1163817

Technical Memorandum Cone Penetration Testing and Discrete-Depth Groundwater Results Pemaco Superfund Site, Maywood, California

1.2. LOCAL HYDROGEOLOGY There are two distinct hydrogeologic units at the Site: a Perched Zone groundwater unit and the regional Exposition Aquifer. Site stratigraphy as it pertains to how groundwater is encountered at the Site is summarized below:

• Perched Zone: Typically found between 25 and 40 feet and occurs in semi-continuous and discontinuous lenses of poorly graded sand, silty sand, and sandy silt. These lenses are located at different depths ranging from 20 and 40 feet below ground surface (bgs) and range from 5 inches to 5 feet in thickness. The geometry of the Perched Zone is controlled by the highly irregular and undulating top surface of the underlying, laterally extensive perching clay.

• Exposition Aquifer: Composed of five distinct water-bearing intervals typically encountered at depths between 65 and 175 feet bgs, and are separated by silt/clay intervals.

o ‘A’ Zone: generally between 65 and 75 feet bgs and is comprised of fine silty and poorly graded sands locally interbedded with well-graded sands ranging in thickness from 0 to 10 feet. As is explained below, CPT locations #1 and #2 failed to identify any ‘A’ Zone north of Slauson Avenue.

o ‘B’ Zone: generally between 80 and 90 feet bgs and is comprised of fine silty sands, poorly graded sands and poorly graded sands with silt ranging in thickness from 1.5 to 10 feet.

o ‘C’ Zone: generally between 100 and 110 feet bgs and is comprised of saturated dark greenish gray fine silty sands, poorly graded sands and poorly graded sands with silt ranging in thickness from 2 to 6 feet.

o ‘D’ Zone: generally between 125 and 145 feet bgs and is comprised of interbedded fine silty sands, poorly graded sands and poorly graded sands with silt, well-graded sands and gravelly sands and local well-graded sandy gravel intervals ranging in thickness from 6 to 15 feet.

o ‘E’ Zone: generally between 160 and 175 feet bgs and is comprised of alternating saturated intervals of 1-foot-thick fine silty sands and well-graded sands; the thickness of this unit has not been characterized.

2.0 FIELD ACTIVITIES Field activities were carried out in accordance with the Work Plan Amendment, Cone Penetration Tests and Discrete-Depth Groundwater Sampling: Task 0615 (Work Plan) (OTIE, 2014). Two sampling deviations from the Work Plan took place; their description and rationale can be found in Section 2.2.1 of this Memorandum.

2.1. UTILITY CLEARANCE The following activities were performed to demarcate utilities in CPT locations:

• Underground Service Alert of Southern California was contacted before beginning any intrusive work. The following tickets were obtained: A3211110-00A, A3211141-00A, A3211154-00A, A3211160-00A, and A3211163-00A.

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• A geophysical utility locator (SubSurface Surveys, Inc., of Carlsbad, California) was subcontracted to clear the ERH Area of subsurface utilities under the direction of an OTIE representative on 26 November 2014.

• Hand augering was performed to a depth between 5 and 8 feet bgs prior to each CPT push. Soil generated during hand augering was used to backfill each respective boring to provide support for advancing the CPT probe.

2.2. CONE PENETRATION TESTING AND DISCRETE-DEPTH GROUNDWATER SAMPLING

2.2.1. Cone Penetration Testing A CPT rig was used to perform the investigative work. CPT is a process of advancing a probe into the subsurface that measures sleeve friction and cone penetration resistance. The ratio of sleeve friction to cone penetration resistance predicts the subsurface lithology (Robertson, 1998). For this investigation, the CPT data allowed for subsurface identification of groundwater bearing zones and facilitated collection of discrete-depth groundwater samples.

The CPT rig was operated by Gregg Drilling and Testing, Inc., (Gregg) of Signal Hill, California, under the supervision of an OTIE geologist.

A total of five CPT profiles (locations) were advanced during field activities (see Figure 2) and a total of 10 groundwater samples were collected as follows:

1. 2014CPT-1 was advanced in the parkway median between Slauson Ave. and 59th Street (north of the Site) on December 17, 2014. The CPT push at this location required use of a separate rock coring rig to penetrate the subsurface concrete that is known as the former District Boulevard. The rock coring was completed on December 5, 2014, after the first 2014CPT-1 effort was rejected on December 1st.

• No water bearing ‘A’ Zone was identified in the 2014CPT-1 profile.

• The ‘B1’ and ‘B2’ Zones were identified in the CPT profile between approximately 84 and 88 feet bgs and 90 and 94 feet bgs, respectively.

• A groundwater sample was collected from the ‘B2’ Zone at approximately 94 feet bgs.

2. 2014CPT-2 was advanced in the parkway median between Slauson Ave. and 59th Street (northwest of the Site) on December 1, 2014.

• No water bearing ‘A’ Zone was identified in the CPT profile.

• The ‘B’ and ‘C’ Zones were identified in the CPT profile between approximately 90 and 92 feet bgs and 112 and 115 feet bgs, respectively.

• Groundwater samples were collected in the ‘B’ Zone at approximately 92 feet bgs and in the ‘C’ Zone at approximately 115 feet bgs.

• Work Plan deviation: A sample was collected in the ‘C’ Zone at CPT boring 2014CPT-2 instead of at 2014CPT-3 (as shown in the Work Plan Amendment) as the preferred location to facilitate offsite delineation of impacted groundwater in the ‘C’ Zone.

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3. CPT profile 2014CPT-3 was advanced immediately north of MW-01-80 in the Maywood Riverfront Park on December 10, 2014.

• Both the ‘A’ and ‘B’ Zones were identified in the CPT profile between approximately 67 and 85 feet bgs and 90 and 95 feet bgs, respectively.

• Groundwater samples were collected in the ‘A’ Zone at approximately 80 feet bgs and in the ‘B’ Zone at approximately 92 feet bgs.

4. 2014CPT-4 was advanced near the middle of Maywood Riverfront Park southwest of MW-01-80 and northeast of MW-20-70 on December 10, 2014.



• Work Plan deviation: a sample was collected in the ‘A’ Zone at CPT boring 2014CPT-4 as a replacement for 2014CPT-2 – where no ‘A’ Zone was observed.

5. 2014CPT-05 was advanced in the parking lot near the southwest corner of Maywood Riverfront Park on December 1, 2014.



Post-investigation, all borings were backfilled from bottom to approximately 5 feet bgs with a Portland-cement grout mixture. The locations of CPT Borings are presented on Figure 2. The CPT logs are provided in Appendix A.

2.2.2. Discrete-Depth Groundwater Sampling Discrete-depth groundwater samples were collected from separate boreholes that were advanced for each individual sample. To collect a discrete-depth groundwater sample, the CPT rod was driven to the desired depth and then retracted three feet to expose the ¾ inch outer diameter polyvinyl chloride 0.020-inch slot screen. A clean stainless steel bailer was used to collect the groundwater, which was immediately transferred to laboratory-supplied containers appropriate for EPA 8260B volatile organic compound (VOC) analysis and for SW8260-SIM 1,4-dioxane analysis. After sample collection, the CPT rod was retracted; for collection of multiple discrete-depth samples at the same location, additional boreholes were advanced at a 2-3 foot radial distance from the original CPT profile location. All samples were labeled and shipped under chain of custody procedures via courier to Eurofins Calscience, Inc., (Calscience) of Garden Grove, California.

Following sample collection, all boreholes were properly destroyed per the approved Work Plan by backfilling from bottom to approximately 5 feet bgs with a Portland-cement grout mixture. Native soil from around the boring location was used to backfill from 5 feet bgs to natural ground surface.

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For quality assurance and quality control (QA/QC) purposes, a duplicate sample and trip blanks were carried out. The duplicate sample was collected at 2014CPT-5 at 90 feet bgs, in the ‘B’ Zone (Sample ID 2014CPT-A-190 in Table 1). Laboratory-supplied trip blanks accompanied each shipment for U.S. EPA 8260B VOC analysis. QA/QC samples were labeled and shipped under chain of custody procedures via courier to Calscience.

3.0 CPT RESULTS – GEOLOGICAL CROSS-SECTION AND LABORATORY ANALYTICAL RESULTS

3.1. SUBSURFACE GEOLOGY A geological cross-section map (Figure 3) was generated from the CPT profile data to update the conceptual site model for the hydrogeologic zones in the vicinity of MW-01-80. The key outcomes from this exercise are that:

• Based on 2014CPT-1 and 2014CPT-2 profiles, no water bearing Exposition ‘A’ Zone exists northof Slauson Avenue, in the immediate vicinity of the Pemaco Site.

• Based on 2014CPT-3 profile, MW-01-80 should be redefined as representative of the Exposition‘A’ Zone. Historically, MW-01-80, was interpreted as being screened through both the Exposition‘A’ and ’B’ Zones.

The ramifications of the geological cross-section map updates are discussed in Section 4.0.

3.2. ANALYTICAL RESULTS Several VOCs were detected during the CPT discrete- depth groundwater sampling which have previously been classified as chemicals of concern (COCs) for the Site (EPA, 2005). The VOCs detected at concentrations exceeding the SSRLs (and their corresponding SSRLs) are:

• Benzene (SSRL 1 µg/L),

• 1,1-dichloroethane (1,1-DCA) (SSRL 5 µg/L),

• 1,1-dichloroethene (1,1-DCE) (SSRL 6 µg/L),

• cis-1,2-dichloroethene (cis-1,2-DCE) (SSRL 6 µg/L),

• 1,4-dioxane (SSRL 1 µg/L),

• TCE (SSRL 5 µg/L), and

• vinyl chloride (VC) (SSRL 0.5 µg/L).

TCE was detected above the SSRLs in all samples collected in each Zone. All analytical results and corresponding SSRLs are provided in Table 1. Analytical data for analytes detected at concentrations exceeding SSRLs are presented on Figure 2. No ‘A’ Zone samples were collected at 2014CPT-1 and 2014CPT-2 because CPT profiles indicated no water-bearing ‘A’ Zone present.

A summary of the analytical results for the VOCs with SSRL exceedances, including TCE, 1,4-dioxane, cis-1,2-DCE, and VC, is provided for the ‘A’, ‘B’ and ‘C’ Zones as follows:

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• ‘A’ Zone Samples:

o TCE concentrations detected in samples ranged from a minimum of 32 µg/L at 2014CPT-5 to a maximum of 530 µg/L at 2014CPT-3.

o 1,4-Dioxane concentrations detected in samples ranged from minimum 2.4 J µg/L at 2014CPT-5 to a maximum of 9.6 J µg/L at 2014CPT-4.

o Cis-1,2-DCE concentrations detected in samples ranged from a minimum of 5.5 µg/L at 2014CPT-5 to a maximum of 16 µg/L at 2014CPT-3.

o VC concentrations detected in samples ranged from a minimum of 2.2 µg/L at 2014CPT-4 to a maximum of 4.2 µg/L at 2014CPT-3.

• ‘B’ Zone Samples:

o TCE concentrations detected in samples ranged from a minimum of 11 µg/L at 2014CPT-1 to a maximum of 580 µg/L at 2014CPT-5.

o 1,4-Dioxane concentrations detected in samples ranged from a minimum of 1.4 J µg/L at 2014CPT-5 to a maximum of 96 J µg/L at 2014CPT-2.

o Cis- 1,2-DCE concentrations detected in samples ranged from a minimum of 18 µg/L at 2014CPT-1 to a maximum of 120 µg/L at 2014CPT-2.

o VC concentrations detected in samples ranged from a minimum of 0.76 µg/L at 2014CPT-4 to a maximum of 3.7 µg/L at 2014CPT-2.

• ‘C’ Zone Sample:

o TCE concentration detected in sample collected at 2014CPT-2 was 44 µg/L.

o 1,4-Dioxane concentration detected in sample collected at 2014CPT-2 was 170 J µg/L.

o Cis-1,2-DCE concentration detected in sample collected at 2014CPT-2 was 120 µg/L.

o VC concentration detected in sample collected at 2014CPT-2 was 2.5 µg/L.

3.3. ANALYTICAL DATA QUALITY All laboratory results data were subjected to an analytical review to assure data validity. The process followed EPA laboratory data validation national functional guidelines for evaluating organic analyses (EPA, 2008). Completeness evaluation confirmed that all data were accounted for and that the quality control package was consistent and complete. Validation involved assessing field, batch, and calibration quality control with respect to acceptance criteria.

The overall quality of the data for this event is good, with completeness at 100% (no data were rejected) and the detections of contaminants are valid and usable data. All groundwater samples were shipped under appropriate chain of custody protocol at the method-specified temperature limit. All analyses were conducted within the specified holding time limit for each method. Concentrations detected above method detection limits, but below the reporting limits, were qualified as quantitative estimates (flagged with “J”).

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Trip blanks are used to determine whether cross-contamination by VOCs has occurred during transportation to the laboratory. Trip blanks were included with samples sent to the laboratory for VOCs analysis. No VOCs were detected in the trip blanks. One field duplicate was collected at location 2014CPT-5 in the ‘B’ Zone to measure the precision of the field sampling and analytical procedures, per the Draft-Final Sampling and Analysis Plan (OTIE, 2015a). The relative percent differences (RPD) calculated for the field duplicate pairs were within the established acceptance limit of 40% for concentrations above the reporting limits, with the following exception:

• 1,4-Dioxane had an RPD of 94%. As a result, all detections of 1,4-dioxane were qualified and denoted with a “J”.

Laboratory QA/QC analysis was performed following specifications of the EPA analytical methods. Laboratory quality control samples included method blanks, laboratory control samples, matrix spike, matrix spike duplicates, laboratory duplicates, internal standards and surrogate spikes as applicable per select EPA methods.

No contamination was detected in the method blanks. Percent recoveries and relative percent differences were within QC limits for matrix spike, matrix spike duplicate analysis. Percent recoveries for laboratory control sample analysis were within QC limits except for VOC analysis associated with all samples in this sampling event. Therefore, precision and accuracy were satisfactory in the laboratory analyses.

4.0 DISCUSSION Pursuant to the Work Plan objectives, this discussion focuses on contaminant concentrations near MW-01-80 and in the western portion of the Site northeast of MW-12-90. Emphasis is given to TCE plume concentrations as this is the COC detected at the highest concentrations and historically has been the best indicator of plume extent. Some discussion of 1,4-dioxane is also included, as the extent of this COC has not been thoroughly understood. The 1,4-dioxane SSRL was defined as 3 µg/L in the Pemaco Record of Decision (ROD), based on the California Department of Public Health notification level (notification level) established in 1998 (EPA 2005). The State revised the notification level in 2010 to 1 µg/L, which is the concentration limit that is used in this discussion.

The CPT analytical results provide greater insight when discussed in combination with the December 2014 semiannual groundwater monitoring event data. Therefore the CPT analytical data and December 2014 semiannual groundwater monitoring data were combined into one group of plume maps for those groundwater zones investigated by CPT. The combined plume maps for TCE in the Exposition ‘A’, ‘B’, and ‘C’ Zones are provided in Appendix B.

Groundwater elevation data was not collected as part of the CPT investigation. Discussion of groundwater gradients and flow, in conjunction with the semiannual groundwater monitoring results and CPT data, is reserved for the semiannual groundwater monitoring report. The Draft Semiannual groundwater monitoring report for the December 2014 sampling event is scheduled for distribution in late April 2015.

4.1. EXPOSITION ‘A’ ZONE COCS IN THE VICINITY OF MW-01-80 As shown in Appendix B, Figure 5-3 from the Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event (TCE Plume in Groundwater Exposition ‘A’ Zone, December 2014) the highest concentrations of TCE in the ‘A’ Zone are located near the northwest corner of the Site in the

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vicinity of 2014CPT-3 and MW-01-80. Concentration decreases gradually towards the southwest based on 2014CPT-4 (250 µg/L) and 2014CPT-5 (32 µg/L) results. Concentrations of TCE also decrease gradually to the south and southeast based on data from MW-21-80 (200 µg/L), DA-01 (50 µg/L), and MW-14-80 (2.3 µg/L). TCE concentrations to the east are derived from MW-22-75. Historically, MW-22-75 has not exceeded SSRLs; the last TCE data at that location was from July 2014 at 0.33J µg/L concentration. Since no water bearing ‘A’ Zone exists at the locations of CPT-1 and CPT-2 there is inconclusive data regarding TCE plume contours north of Slauson Avenue.

The best available data suggests that the TCE 5 µg/L concentration plume, which represents the SSRL threshold, covers the northwest portion of the Site and extends southward to the vicinity of the 59th Place & Walker Avenue intersection. The ERH Treatment Area and the area to the south remain below the TCE 5 µg/L SSRL concentration.

Data from CPT-3 and CPT-4 (Figure 2) shows 1,4-dioxane concentrations exceeding the notification level (7.9 J µg/L and 9.6 J µg/L, respectively). Historical concentration data in this area at MW-01-80 indicated 1,4-dioxane was present at 4.0 µg/L (in 2013) and 6.7 µg/L (in 2006). The CPT data indicates a low concentration 1,4-dioxane plume in the ‘A’ Zone reaching to the north and west of the Site in the vicinity of MW-01-80. The 1,4-dioxane concentration decreases to the southwest based on CPT-5 (2.4 J µg/L) results.

The absence of a water-bearing ‘A’ Zone north of Slauson Avenue decreases the probability that COCs detected in the vicinity of MW-01-80 migrated from the north. Nevertheless, due to complicated and variable lithology, a meandering pathway from the north that was not detected by the CPT-1 and 2 profiles cannot be ruled out.

The CPT drilling and sampling activities improved the understanding of COC concentrations in the ‘A’ Zone in the vicinity of MW-01-08 and extending to the southwest, however data gaps to the west and northwest of this location remain.

4.2. EXPOSITION ‘B’ ZONE COCS IN THE VICINITY OF MW-1-80 As shown in Appendix B, Figure 5-6 from the Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event (TCE Plume in Groundwater Exposition ‘B’ Zone, December 2014) the highest TCE concentrations in the ‘B’ Zone were detected at MW-02-95 (1,000 µg/L) and at CPT-5 (650 µg/L). CPT-5 is located to the west of the Site, upgradient from MW-12-90, near the former W.W. Henry mixing area. Refer to Figure 3 in Appendix C, for a historic map showing the location of the W.W. Henry facilities.

Figure 5-6 also serves to identify an expanded 50 µg/L TCE plume contour, compared to historical ‘B’ Zone plume maps, that now includes most of Maywood Riverfront Park (the Park) between 59th Place and Slauson Avenue. Concentrations of TCE at CPT locations 2, 3, and 4 are approximately equal (52 µg/L, 59 µg/L, and 56 µg/L, respectively). Based on data from the surrounding wells the TCE concentrations at CPT locations 2, 3, and 4 are characteristic of the mid-plume.

TCE concentrations do not increase to the north, as shown by CPT-1 (11 µg/L) and CPT-2 results (52 µg/L), which reduces the probability that ‘B’ Zone COCs migrated from the north to the CPT-3 and 4 vicinity. Higher TCE concentrations are found to the southwest at CPT-5 (650 µg/L), to the southeast at MW-02-95 (1,000 µg/L) (Figure 5-6), and in the ‘A’ Zone at MW-01-80 (530 µg/L) (Figure 5-3). Any one or

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combination of these three higher concentration areas may be contributing to the mid-plume TCE concentrations found near CPT-3 and 4. A data gap does not allow for a conclusion about the extent of TCE concentrations to the west and northwest.

Historical data shows TCE concentrations exceeding the SSRL in the near vicinity of CPT-2 as early as 2001. A comparison of the 2001 data to the 2014 CPT data can be found in Appendix D.

Concentrations of 1,4-dioxane in the ‘B’ Zone shows a differing pattern to that of TCE. The highest concentrations of 1,4-dioxane are found to the northwest of the site at CPT-2 (96 J µg/L) and decrease towards the east (7.4 J µg/L at CPT-1), south (19 J µg/L at CPT-4) and southwest (1.4 J µg/L at CPT-5). A data gap to the west and northwest prevents characterization of the 1,4-dioxane plume in those directions.

4.3. EXPOSITION ‘C’ ZONE COC concentration data for the ‘C’ Zone has been limited to the monitoring well locations in the southeast portion of the Site. The 2014 data from CPT-2 (Figure 2) indicates groundwater contamination in the ‘C’ Zone in the northern side of the Site, which includes four COCs that exceed SSRLs.

As shown in Appendix B, Figure 5-9 from the Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event (TCE Plume in Groundwater Exposition ‘C’ Zone, December 2014), concentrations of TCE increase to the south of the Site based on data from MW-23-110 (420 µg/L) and MW-05-105 (640 µg/L). TCE concentration drops below the SSRL to the southeast in the vicinity of the ERH treatment area (2.4J µg/L at MW-34-110), and to the southwest at MW-10-110 (2.4 µg/L).

The concentration of 1,4-dioxane in the ‘C’ Zone was 170 J µg/L at CPT-2 to the north of the Site. This was the highest 1,4-dioxane concentration detected in any of the CPT groundwater samples analyzed in any Zone. Historical concentration data for the ‘C” Zone monitoring wells located to the south and southeast (including the December 2014 semiannual groundwater monitoring event results) show non-detect or values close to the notification level of 1 µg/L for 1,4-dioxane.

The ‘C’ Zone has not been extensively examined to the west and northwest of the Site. The data gap in these areas prevents characterization of TCE and 1,4-dioxane concentrations in those directions.

5.0 CONCLUSIONS AND RECOMMENDATIONS The objective of the CPT investigation was to facilitate an understanding of TCE concentrations to the north of the Site, upgradient of MW-01-80, and in the western portion of the Site, north of MW-12-90.

Groundwater sample analytical results from the CPT investigation were paired with results from the December 2014 Semiannual Groundwater Monitoring Event, to construct TCE plume maps for the ‘A’, ‘B’, and ‘C’ Zones in the Exposition Aquifer (Appendix B). This new set of plume maps enabled a characterization of contaminant extent farther north and west of the Site than previous monitoring efforts allowed.

In addition, the CPT data provided an improved understanding of subsurface geology, particularly in the northern portion of the Site. The data was incorporated into an updated geological cross-section map (Figure 3) and key updates to the conceptual site model of the hydrogeological zones include:

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• No water-bearing Exposition ‘A’ Zone exists directly north of Slauson Avenue (based on 2014CPT-1 and 2014CPT-2 profiles).

• MW-01-80 is representative of the Exposition ‘A’ Zone. Historically, MW-01-80, was interpreted as being screened through both the Exposition ‘A’ and ’B’ Zones.

The CPT investigation confirmed the presence of contaminant plumes in the ‘A’, ‘B’, and ‘C’ Zones in the northern and/or western portions of the Park. The detected contaminants have all been historically present in groundwater plumes attributed to the Pemaco Site. Data gaps north of Slauson Avenue and northwest of the Park, in the vicinity of Alamo Avenue and Slauson Avenue, prevent confirmation of the plume’s northern and western boundaries in all three hydrogeologic Zones. Additional CPT investigation is recommended to fill these concentration data gaps and to help position additional wells (a recommendation from the forthcoming Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event) that will be used to fill groundwater gradient data gaps.

Recommendations include:

• Ten additional CPT/hydro punch borings installed north of Slauson Avenue and northwest of the Park, in the vicinity of Alamo Avenue and Slauson Avenue.

• For improved characterization of the 1,4-dioxane plume, increase the number of wells for 1,4-dioxane analysis, to match the number of wells sampled for VOCs analysis.

• Well installations will be recommended as part of the Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event, to resolve groundwater gradient data gaps in the ‘A’, ‘B’, and ‘C’ Zones.

6.0 REFERENCES Oneida Total Integrated Enterprises, LLC. (OTIE). 2014. Work Plan Amendment Cone Penetration Tests

and Discrete-Depth Groundwater Sampling: Task 0615. October 29.

_____. 2015a. Draft-Final Sampling and Analysis Plan, (Field Sampling Plan and Quality Assurance Project Plan), Long-Term Response Action for the Pemaco Remedial Action, Pemaco Superfund Site, 5050 E. Slauson Avenue, Maywood, California. February.

_____. 2015b (in production). Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event, for the Pemaco Superfund Site, Maywood, California.

Robertson, P. K. 1998. Applications Guide—CPT. ConeTec, Inc.

TN and Associates. 2002. Technical Memorandum – Results of In-Situ Groundwater Sampling in the Perched Zone and Upper Exposition Groundwater Zone, February and November 2001. February 19.

_____. 2004. Final Feasibility Study Report, Pemaco Superfund Site, 5050 E. Slauson Avenue Maywood, California. February.

United States Environmental Protection Agency (U.S. EPA) Region IX. 2005. Record of Decision for Pemaco Maywood Superfund Site, Maywood, California. U.S. EPA ID: CAD980737092. January 13.

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_____. 2008. Contract Laboratory Program National Functional Guidelines for Superfund Organic Methods Data Review, USEPA-540-R-08-01. June.

ATTACHMENTS Figures

Figure 1: Site Location Map

Figure 2: Groundwater Analytical Results, Cone Penetration Test, December 2014

Figure 3: Cross Section Map A – A’

Tables

Table 1 Groundwater Analytical Results - Cone Penetration Test Samples

Graphs

Graph 1 Trichloroethene (TCE) Concentration versus Time, MW-01-80

Graph 2 Trichloroethene (TCE) Concentration versus Time, MW-12-90

Appendices

Appendix A 2014 CPT Field Logs

Appendix B Trichloroethene Plume Maps (from the Draft Semiannual Groundwater Monitoring Report, December 2014 Monitoring Event)

Appendix C Original Site Plan

Appendix D ‘B’ Zone Comparison of 2001 CPT and 2014 CPT

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FIGURES

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Approximate Scale in Feet

0 100 200

LEGEND:

2014CPT-#

Former Pemaco Property

Maywood Riverfront Park Boundary


0 100 200

LEGEND:

NOTES:

2014CPT-# 2014 CPT Location


ERH and Treatment Compound Area

1. All analyte concentrations are expressed in μg/L.2. Red highlighting indicates a result that exceeds the

SSRL.3. Bold font indicates an anlytical detection.4. Groundwater SSRLs (μg/L):

1,1-DCA: 51,1-DCE: 6Benzene: 11,4-Dioxane: 1 (adopted)cis-1,2-DCE: 6PCE: 5TCE: 5VC: 0.5

U.S. EPA = United States Environmental ProtectionAgency, Region 9ERH = Electrical Resistive HeatingSSRL = Site Specific Remediation Limitμg/L = micrograms per liter1,1-DCA = 1,1-Dichloroethane1,1-DCE = 1,1-Dichloroethenecis-1,2-DCE = cis-1,2-DochhloroethenePCE = TetrachloroetheneTCE = TrichloroetheneVC = Vinyl ChlorideN = normal sampleFD = field duplicateJ = estimated value N

S

EW

MW-33A

MW-22-75U.S. EPA, Monitoring Well, Exposition Aquifer

W.W. Henry, Monitoring Well

H

H

MW-04-90

MW-06-85

MW-05-85

MW-04-75

MW-19-70

MW-14-80

MW-21-80

MW-01-80

MW-20-70

B-19

B-08

MW-26-75

MW-27-70

SV-01

SV-03

SV-04

SV-05

59th

Pla

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A

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MW-30-90

L

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E

S

R

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MW-14-90

MW-26-90

MW-19-90

MW-27-90

MW-33A

2014CPT-2

2014CPT-4

MW-33B

Oneida Total Integrated Enterprises

N

S

EW


0 75

INSET MAP LEGEND:

MW-33A


U.S. EPA, Recovery Well, Exposition Aquifer(Currently Used as a Monitoring Well)RW-01-70

U.S. EPA, Extraction Well, Individual Screensfor the 'B' Zone

DB-1

W.W. Henry, Monitoring Well

2014CPT-# 2014 CPT Location


Electrical Resistive Heating (ERH) Area

Concrete Concrete

ConcreteSubgrade B-2520

01CPT-5

GP-VS-29

B-26

MW-04

GP-VS-23

B-12GP-VS-17

B-11B-10B-082001

CPT-4

B-07B-01

A A'

MW-15MW

-14

NORTH SOUTH

A ZONE

PERCHEDZONE

MW-21

-90

MW-01

-802014

CPT-3

2014

CPT-2

DB-09

A ZONE

B ZONEB ZONE

LOWER VADOSEZONE SAND

LOWER VADOSEZONE SAND

PERCHEDZONE

C ZONE

Date:

File:


Figure 3Cross Section A - A'

February 19, 2015

Pem_CPT_XSec.dwg

Slauson Avenue

Pemaco Property

ERH Area

A'

A

Cross Section Reference LineA A'

M

W

-

0

1

-

8

0

SW

Well/CPT ID

Ground Surface

USCS Classification

'A' Zone GroundwaterPotentiometric Surface

Well Screen IntervalBottom of Boring

Fill Material

Coarse Grained LithosomesSP = Poorly Grade SandsSW = Well Graded SandsSM = Silty Sands

Fine Grained LithosomesML = SiltCH = Fat Clay (highly plastic clay)CL = Lean Clay (low plasticity clay)

CROSS SECTION LEGEND:

'B' Zone GroundwaterPotentiometric Surface

Approximate Scale in Feet(6X Vertical Exaggeration)

GEOLOGIC ZONES OF INTEREST:

• Perched Groundwater Zone, typically found between 25 and 40 ft bgs. Groundwater in the Perched Zoneoccurs in semi-continuous and discontinuous lenses of poorly graded sand, silty sand, and sandy silt.These lenses are located at different depths ranging from 20 to 40 ft bgs and range from 0.5 to 5 ft inthickness. The top of groundwater in wells screened in this zone typically ranges from 20 to 30 ft bgs withoverall apparent flow towards the southwest.

• Perching Clay, from 28 to 40 ft bgs (typical depth) - silty lean and fat clays underlain and interbedded withclayey and sandy silts.

• Lower Vadose Zone - comprised of sand from 40 to 50 ft bgs and a fine-grained unit (sandy and clayey siltsinterbedded with clay) between 50 to 65 ft bgs.

• Exposition Aquifer Zones 'A' through 'E' - There are five distinct saturated sandy intervals separated bysilt/clay intervals that are typically found between 65 and 175 ft bgs. These five units have been informallynamed from top to bottom the Exposition 'A' through 'E' zones.

• 'A' Zone occurs between approximately 65 and 75 ft bgs• 'B' Zone occurs from approximately 80 to 90 ft bgs• 'C' Zone occurs from approximately 95 to 110 ft bgs• 'D' Zone occurs from approximately 125 to 145 ft bgs, and• 'E' Zone occurs from approximately 160 to 175 ft bgs.

No SSRLExeedences

No SSRLExeedences

1. Groundwater analytical data and elevations frommonitoring wells collected in December 2014.

2. All analyte concentrations are expressed in μg/L.3. Chem. boxes show only SSRL exceedences, all

other analytes (not shown) were below SSRLs.4. Groundwater SSRLs (μg/L):

Benzene: 1cis-1,2-DCE: 6TCE: 5VC: 0.51,4-Dioxane: 1 (adopted)

U.S. EPA = United States Environmental ProtectionAgency, Region 9SSRL = Site Specific Remediation Limitμg/L = micrograms per literCOCs = contaminants of concerncis-1,2-DCE = cis-1,2-DichhloroetheneTCE = TrichloroetheneVC = Vinyl ChlorideJ = estimated value

NOTES:

A ZONE

No SSRLExeedences

A ZONE

TABLES

Table 1Groundwater Analytical Results - Cone Penetration Test Samples


2014CPT-11

2014CPT-21

2014CPT-22

2014CPT-32

2014CPT-3 2014CPT-43

2014CPT-4 2014CPT-5 2014CPT-5 2014CPT-54

94 ft bgs 92 ft bgs 115 ft bgs 80 ft bgs 92 ft bgs 78 ft bgs 92 ft bgs 75 ft bgs 90 ft bgs 90 ft bgs

Exposition Zone 'B' Zone 'B' Zone 'C' Zone 'A' Zone 'B' Zone 'A' Zone 'B' Zone 'A' Zone 'B' Zone 'B' Zone

2014CPT-1-94 2014CPT-2-92 2014CPT-2-115 2014CPT-3-80 2014CPT-3-92 2014CPT-4-78 2014CPT-4-92 2014CPT-5-75 2014CPT-5-90 2014CPT-A-190

12/17/2014 12/4/2014 12/4/2014 12/10/2014 12/10/2014 12/10/2014 12/10/2014 12/1/2014 12/1/2014 12/1/2014

N N N N N N N N N FD

Analyte Name SSRL/MCL Units

1,1,1-Trichloroethane 200* μg/L 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 1.5 U 1.5 U1,1,2,2-Tetrachloroethane 1* μg/L 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 2 U 2 U1,1,2-Trichloro-1,2,2-Trifluoroethane 1200* μg/L 0.78 U 0.78 U 0.78 U 0.78 U 0.78 U 0.78 U 0.78 U 0.78 U 3.9 U 3.9 U1,1,2-Trichloroethane 5 μg/L 0.38 U 0.38 U 0.38 U 0.38 U 0.38 U 0.38 U 0.38 U 0.38 U 1.9 U 1.9 U1,1-Dichloroethane 5 μg/L 0.98 J 4.9 4.4 1.6 1.2 6.8 0.88 J 0.46 J 7.1 7.8

1,1-Dichloroethene 6 μg/L 1.4 3.5 2.9 4.5 0.69 J 14 0.83 J 0.43 U 4.1 J 3.4 J

1,2,3-Trichlorobenzene NC μg/L 0.51 U 0.51 U 0.51 U 0.51 U 0.51 U 0.51 U 0.51 U 0.51 U 2.5 U 2.5 U1,2,4-Trichlorobenzene 5* μg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 2.5 U 2.5 U1,2-Dibromo-3-Chloropropane 0 μg/L 1.2 U 1.2 U 1.2 U 1.2 U 1.2 U 1.2 U 1.2 U 1.2 U 6.2 U 6.2 U1,2-Dibromoethane NC μg/L 0.36 U 0.36 U 0.36 U 0.36 U 0.36 U 0.36 U 0.36 U 0.36 U 1.8 U 1.8 U1,2-Dichlorobenzene 600* μg/L 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 2.3 U 2.3 U1,2-Dichloroethane 0.5 μg/L 0.24 U 7 5.9 0.24 U 0.59 0.24 U 0.58 0.24 U 1.2 U 1.2 U1,2-Dichloropropane 5* μg/L 0.42 U 0.42 U 0.42 U 0.42 U 0.42 U 0.42 U 0.42 U 0.42 U 2.1 U 2.1 U1,3-Dichlorobenzene NC μg/L 0.4 U 0.4 U 0.4 U 0.4 U 0.4 U 0.4 U 0.4 U 0.4 U 2 U 2 U1,4-Dichlorobenzene 5* μg/L 0.43 U 0.43 U 0.43 U 0.43 U 0.43 U 0.43 U 0.43 U 0.43 U 2.2 U 2.2 U1,4-Dioxane (P-Dioxane) 1** μg/L 7.4 J 96 J 170 J 7.9 J 32 J 9.6 J 19 J 2.4 J 1.4 J 3.9 J

2-Butanone NC μg/L 2.2 U 2.2 U 2.2 U 2.2 U 2.2 U 2.2 U 2.2 U 2.2 U 11 U 11 U2-Hexanone NC μg/L 2.1 U 2.1 U 2.1 U 2.1 U 2.1 U 2.1 U 2.1 U 2.1 U 10 U 10 U4-Methyl-2-pentanone 2,000 μg/L 4.4 U 4.4 U 4.4 U 4.4 U 4.4 U 4.4 U 4.4 U 4.4 U 22 U 22 UAcetone 5,500 μg/L 10 U 10 U 10 U 10 U 10 U 10 U 10 U 10 U 50 U 50 UBenzene 1 μg/L 0.14 U 0.71 0.68 1.1 0.2 J 0.26 J 0.14 U 0.19 J 0.71 U 0.71 UBromochloromethane NC μg/L 0.48 U 0.48 U 0.48 U 0.48 U 0.48 U 0.48 U 0.48 U 0.48 U 2.4 U 2.4 UBromodichloromethane NC μg/L 0.21 U 0.21 U 0.21 U 0.21 U 0.21 U 0.21 U 0.21 U 0.21 U 1 U 1 UBromoform NC μg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 2.5 U 2.5 UBromomethane NC μg/L 3.9 U 3.9 U 3.9 U 3.9 U 3.9 U 3.9 U 3.9 U 3.9 U 19 U 19 UCarbon disulfide NC μg/L 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 0.41 U 2 U 2 UCarbon tetrachloride 0.5* μg/L 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 1.1 U 1.1 UChlorobenzene NC μg/L 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.86 U 0.86 UChloroethane 100 μg/L 2.3 U 2.3 U 2.3 U 2.3 U 2.3 U 2.3 U 2.3 U 2.3 U 11 U 11 UChloroform 80 μg/L 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 2.3 U 2.3 UChloromethane NC μg/L 1.8 U 1.8 U 1.8 U 1.8 U 1.8 U 1.8 U 1.8 U 1.8 U 8.8 U 8.8 Ucis-1,2-Dichloroethene 6 μg/L 18 120 120 16 45 5.7 27 5.5 57 53

cis-1,3-Dichloropropene 0.5* μg/L 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 1.2 U 1.2 UDibromochloromethane 80 μg/L 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 1.2 U 1.2 U

Sample Location

Depth

Sample ID

Sample Date

Sample Type

OTIE


Page 1 of 2



2014CPT-11

2014CPT-21

2014CPT-22

2014CPT-32

2014CPT-3 2014CPT-43

2014CPT-4 2014CPT-5 2014CPT-5 2014CPT-54

94 ft bgs 92 ft bgs 115 ft bgs 80 ft bgs 92 ft bgs 78 ft bgs 92 ft bgs 75 ft bgs 90 ft bgs 90 ft bgs

Exposition Zone 'B' Zone 'B' Zone 'C' Zone 'A' Zone 'B' Zone 'A' Zone 'B' Zone 'A' Zone 'B' Zone 'B' Zone

2014CPT-1-94 2014CPT-2-92 2014CPT-2-115 2014CPT-3-80 2014CPT-3-92 2014CPT-4-78 2014CPT-4-92 2014CPT-5-75 2014CPT-5-90 2014CPT-A-190

12/17/2014 12/4/2014 12/4/2014 12/10/2014 12/10/2014 12/10/2014 12/10/2014 12/1/2014 12/1/2014 12/1/2014

N N N N N N N N N FD

Analyte Name SSRL/MCL Units

Sample Location

Depth

Sample ID

Sample Date

Sample Type

(Analytes Continued)

Dichlorodifluoromethane NC μg/L 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 0.46 U 2.3 U 2.3 UEthylbenzene 300 μg/L 0.14 U 0.14 U 0.14 U 0.14 U 0.14 U 0.14 U 0.14 U 0.14 U 0.69 U 0.69 UIsopropylbenzene NC μg/L 0.58 U 0.58 U 0.58 U 0.58 U 0.58 U 0.58 U 0.58 U 0.58 U 2.9 U 2.9 UMethyl tert-Butyl Ether 13 μg/L 0.31 U 0.31 U 0.31 U 0.31 U 0.31 U 0.38 J 0.31 U 0.31 U 1.5 U 1.5 UMethylene chloride 5 μg/L 0.64 U 0.64 U 0.64 U 0.64 U 0.64 U 0.64 U 0.64 U 0.64 U 3.2 U 3.2 UStyrene 100* μg/L 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.17 U 0.86 U 0.86 UTetrachloroethene 5 μg/L 0.39 U 0.39 U 0.39 U 0.39 U 0.39 U 0.39 U 0.39 U 0.39 U 1.9 U 1.9 UToluene 150 μg/L 0.24 U 0.24 U 0.24 U 0.24 U 0.24 U 0.24 U 0.24 U 0.24 U 1.2 U 1.2 Utrans-1,2-Dichloroethene 10 μg/L 0.51 J 3.6 3.4 0.54 J 1 0.41 J 0.56 J 0.37 U 3.2 J 3 J

trans-1,3-Dichloropropene 0.5* μg/L 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U 1.3 U 1.3 UTrichloroethene 5 μg/L 11 52 44 530 59 250 56 32 580 650

Trichlorofluoromethane 150* μg/L 1.7 U 1.7 U 1.7 U 1.7 U 1.7 U 1.7 U 1.7 U 1.7 U 8.3 U 8.3 UVinyl chloride 0.5 μg/L 0.94 3.7 2.5 4.2 1.3 2.2 0.79 0.3 U 2.2 J 1.7 J

Xylene, o 1750* μg/L 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 0.23 U 1.1 U 1.1 UXylenes, m & p 1750* μg/L 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 0.3 U 1.5 U 1.5 U

Table Notes:1. No 'A' Zone sample was collected because cone penetration test data indicated no water-bearing 'A' Zone. 2. A sample was collected in the 'C' Zone at 2014CPT-2 instead of at 2014CPT-3 to facilitate offsite delineation of impacted groundwater in the 'C' Zone.

4. Blind duplicate collected at 2014CPT-5-90 ('B' Zone).

6. Bold indicates a detection.7. Yellow shading indicates a concentration in excess of SSRL.8. "*" indicates an MCL used in the absence of a SSRL.9. "**" indicates value is a "California Notification Level" which is less than the SSRL of 3.0, listed in the ROD (EPA 2005).10. SSRL for xylenes is the sum of the ortho-, meta-, and para-isomers.11. Analytical Methods: Samples were analyzed for VOC using method 8260B and for 1,4-dioxane by the using method SW8260-SIM and by Eurofins Calscience, Inc., of Garden Grove, California.

5. Definitions: μg/L = micrograms per liter; ID = identification; J = estimated value; NA = not available; NC = no criteria; SSRL = site-specific remediation level; MCL = maximum contaminant level; SIM = single ion method; semi-volatile organics analysis = SVOA; VOCs = volatile organic compounds; U = not detected above reporting limit; UJ = not detected above estimated reporting limit, N = normal sample; FD = field duplicate; ft bgs = feet below ground surface.

3. A sample was collected in the 'A' Zone at 2014CPT-4 to supplement no 'A' Zone sample collected at 2014CPT-2.

Table 1Groundwater Analytical Results - Cone Penetration Test SamplesPage 2 of 2 OTIE

GRAPHS

OTIE Page 1 of 1

0.1

1.0

10.0

100.0

1,000.0

10,000.0

Co

nce

ntr

atio

n o

f TC

E (m

icro

gram

s p

er

lite

r)

Graph 1 Trichloroethene (TCE) Concentration versus Time

MW-01-80 Pemaco Superfund Site

Maywood, California

MW-01-80 Nondetect Site Specific Remediation Level for Trichloroethene

OTIE Page 1 of 1

0.0

0.1

1.0

10.0

100.0

1,000.0

10,000.0

Co

nce

ntr

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f TC

E (m

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gram

s p

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lite

r) Graph 2

Trichloroethene (TCE) Concentration versus Time MW-12-90


MW-12-90 Site Specific Remediation Level for Trichloroethene

Data flagged 10 U in 2001

Data all non-detect prior to 2012

APPENDIX A

2014 CPT Field Logs

CPT-1 CPT-2 CPT-3 CPT-4 CPT-5

CPT Soil Profiles provided by Gregg Drilling & Testing, Inc.

CPT-1 CPT-2 CPT-3 CPT-4 CPT-5

CPT Cone Resistance Profiles provided by Gregg Drilling & Testing, Inc.

APPENDIXB

Trichloroethene Plume Maps

(from the Draft Semiannual Groundwater Monitoring

Report, December 2014 Monitoring Event)

! C

f <:{' 0 E ~

MW-12- o_l._ Dry T

~ ParkWay/Median

Slauson Avenue

.,.2014CPT-4 .._ 250

DA-I 3t:'\ D \!I

DA-06t:'\ Dry \!I DA-08t:'\

Dry \!I

LEGEND: 0DA-02

0DA-01

-+-MW-22-75

-Q-RW-01 -70

U.S. EPA, Extraction Well, Individual Screens for the 'A' Zone

U.S. EPA, "Active" Extraction Well, Individual Screens for the 'A' Zone

U.S. EPA, Monitoring Well , Exposition Aquifer

U.S. EPA, Recovery Well, Exposition Aquifer (Currently Used as a Monitoring Well)

~ MW-33A W .W . Henry Well W.W. Henry 5100 59th Place, Property 7 from Alamo Corner

._ 2014CPT-# 2014 CPT Location

500 µg/L TCE lsoconcentration Contour



200 TCE Concentration (µg/L)

Dry Dry Indicates less than six inches of water in well Wells have a 6 inch sump

ERH Treatment Area


CJ CJ r::J CJ


Site Fencing

NOTES:

1. All analyte concentrations are expressed in µg/L. 2. The SSRL for TCE is 5 µg/L. 3. Where duplicate samples were analyzed, the higher

concentration is shown. 4. Wells without results were not sampled during the second

semi-annual groundwater monitoring event.

µg/L = micrograms per liter ERH = Electrical Resistive Heating J = estimated value NS = not sampled SSRL = Site Specific Remediation Limit TCE = Trichloroethene U = not detected above reporting limit U.S. EPA= United States Environmental Protection Agency,

Region 9


0 100 200

Figure 5-3 Trichloroethene Plume in Groundwater

Exposition 'A' Zone, December 2014


~4 ::0TIE

OneldaTotallntegratedEnt8fl)rlses

Date: February 18, 2015

File: Pem_Site_Plume_02SA14.dwg

H H

H

H

MW-04-90

MW-06-85

MW-05-85

E 60th

S

treet

59th

P

lace

Slauson Avenue

5

9

th

S

tr

e

e

t

A

lam

o A

ven

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W

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L

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A

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MW-30-90

L

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MW-09-85

MW-12-90

MW-26-90

MW-19-90

MW-27-90

MW-08-85

MW-28B

2014CPT-1

2014CPT-2

2014CPT-3

2014CPT-4

2014CPT-5

Park

way/M

ed

ian

W.W. Henry

5

5

?

?

?

500 500

50

50

50?

MW-13-85

Date:

File:


Oneida Total Integrated Enterprises

LEGEND:

DB-02


U.S. EPA, Recovery Well, Exposition Aquifer(Currently Used as a Monitoring Well)RW-01-95

W.W. HenryMW-28B W.W. Henry Well

5100 59th Place, Property 7 from Alamo Corner

U.S. EPA, "Active" Extraction Well, IndividualScreens for the 'B' Zone

Figure 5-6Trichloroethene Plume in GroundwaterExposition 'B' Zone, December 2014

February 18, 2015

Pem_Site_Plume_02SA14.dwg

N

S

EW


0 110 220

NOTES:



Site Fencing

500 μg/L TCE Isoconcentration Contour



ERH Treatment Area

TCE Concentration (μg/L)280

Dry Indicates less than six inches of water in wellWells have a 6 inch sump

Dry

1. All analyte concentrations are expressed in μg/L.2. The SSRL for TCE is 5 μg/L.3. Where duplicate samples were analyzed, the higher

concentration is shown.4. Wells without results were not sampled during the second


μg/L = micrograms per literERH = Electrical Resistive HeatingJ = estimated valueNS = not sampledSSRL = Site Specific Remediation LimitTCE = TrichloroetheneU = not detected above reporting limitU.S. EPA = United States Environmental Protection Agency, Region 9

2014CPT-#2014CPT-# 2014 CPT Location

U.S. EPA, Extraction Well, Individual Screensfor the 'B' Zone

DB-01

TCE Isoconcentration of a Topographic LowContour

TCE Isoconcentration of a Topographic HighContour

~ Parkway/Median

Slauson Avenue

"'2014CPT-4 "" NS

-+-W-10- 0 2.4

e 60th Place

LEGEND:

-+-Mw-23_110 U.S. EPA, Monitoring Well , Exposition Aquifer

.. 2014CPT-# 2014 CPT Location


50 µg/L TCE lsoconcentration Contour (dashed where inferred)

5 µg/L TCE lsoconcentration Contour (dashed where inferred)

420 TCE Concentration (µg/L)

ERH Treatment Area


CJ CJ r::J CJ


Site Fencing

NOTES:

1. All analyte concentrations are expressed in µg/L. 2. The SSRL for TCE is 5 µg/L. 3. Where duplicate samples were analyzed, the higher

concentration is shown. 4. Wells without results were not sampled during the second


µg/L = micrograms per liter AB = access blocked ERH = Electrical Resistive Heating J = estimated value NS = not sampled SSRL = Site Specific Remediation Limit TCE = Trichloroethane U = not detected above reporting limit U.S. EPA= United States Environmental Protection Agency,

Region 9


0 115 230

Figure 5-9 Trichloroethene Plume in Groundwater Exposition 'C' Zone, December 2014


~4 ::0TIE

OneldaTotallntegratedEnt8fl)rlses

Date: February 18, 2015

File: Pem_Site_Plume_02SA14.dwg

APPENDIX C

Original Site Plan

--FOAMER

lllCING PATIO

PRECISION ARROW PROPERTY

RESIDENTIAL

FOAMER WW HENRY WAREHOUSE

f'CIRIIER !'£MACO WAREHOUSE

--

__ __..----PEMACO SITE BOUNDARY

\ y/\

\ \

\ \

y\ \ \

r=RAQ( \ (SUPERIMPOSED ON 1llP OF USTo)

y\ \

\:::::::.. \

... 0

\I\

\ \

...

......., .... .,._

~ - - FE'A1IRS r--, L __ J FIRERDRUll""'""'"-,s

SITE PLAN ILLUSTRATING LOCATIONS OF FORMER

ENVIRONMENTAL FEATURES

PEMACO SUPERFUND SITE eoeoMA=,.,~,oi:.~uE

T N & Associates, Inc.

Engineering and Science

FIGURE

J

APPENDIX D

‘B’ Zone Comparison of 2001 CPT and 2014 CPT

‘B’ ZONE COMPARISON OF 2001 CPT RESULTS AND 2014 CPT RESULTS

A 2001 cone penetration testing (CPT) investigation was performed in which two of the test locations (2001CPT-35 and 34) are close enough to the 2014 CPT test locations of 2014CPT-01 and 02, respectively, to allow comparison of groundwater analytical data. The 2001 CPT locations are provided in this appendix on the original Figure 11 from the Technical Memorandum-Results of In-Situ Groundwater Sampling in the Perched Zone and Upper Exposition Groundwater Zone, February and November 2001 (TN and Associates, February 2002).

In comparing Appendix D, Figure 11 with Figure 2 from the subject 2014 Technical Memorandum, CPT and Discrete-Depth Groundwater Results, location 2001CPT-35 is adjacent to 2014CPT-1 and 2001CPT-34 is several feet west of 2014CPT-2.

A comparison of the 2001/2014 analytical results are provided in Table 4-1.

Table 4-1: Comparison of Analytical Results between 2001 and 2014 Discrete-Depth Groundwater Samples.

CPT Location 2001CPT-35 2014CPT-1 2001CPT-34 2014CPT-2

Depth/Zone 90 feet bgs/’B’ 92 feet bgs/’B’ 88 feet bgs/’B’ 94 feet bgs/’B’

Benzene 5.1 <0.14 0.63 0.71

1,1-DCA <0.5 0.98J 4.9 4.9

1,4-Dioxane NA 7.4 J NA 96 J

PCE <1.0 <0.39 <1.0 <0.39

TCE <1.0 11 71 52

1,1-DCE <1.0 1.4 1.1 3.5

cis-1,2-DCE <1.0 18 16 120

VC <0.5 0.94 0.88 3.7

Notes: 1. NA = not analyzed for; <# = not detected below the given detection limit; J = quantitative estimates. 2. SSRL exceedances are in bold font. 3. 1,1-DCA = 1,1-Dichloroethane; PCE = tetrachloroethene; TCE = trichloroethene; 1,1-DCE = 1,1-Dichloroethene; cis-1,2-DCE =

cis-1,2-Dichloroethene; VC = vinyl chloride.

Comparison of the 2001/2014 data in Table 4-1 resulted in three general observations for the ‘B’ Zone groundwater:

In 2001, TCE was not detected at location 2001CPT-35; however TCE concentrations at 2001CPT-34 were above the SSRLs.

At 2014CPT-1, TCE and cis-1,2-DCE have increased from non-detect in 2001 to SSRL exceedances in 2014, while benzene has decreased.

At 2014 CPT-2, TCE concentrations have decreased over time while dechlorination daughter products (cis-1,2-DCE and VC) have increased.

Both 2014CPT-1 and 2014CPT-2 show SSRL exceedances for 1,4-dioxane. 1,4-Dioxane data was not available in 2001 for comparison.

REFERENCES

TN and Associates. 2002. Technical Memorandum – Results of In-Situ Groundwater Sampling in the Perched Zone and Upper Exposition Groundwater Zone, February and November 2001. February 19.

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Documents

Technical Memo: Cone penetration testing & discrete · PDF fileTechnical Memorandum Cone Penetration Testing and Discrete-Depth Groundwater Results Pemaco Superfund Site, Maywood,