Challenging and Innovative Projects

Cost-Effective UST Removal

Los Angeles, California

We were retained by a confidential client to remove 50 underground storage tanks (USTs) with a maximum capacity of 30,000 gallons containing chlorinated VOCs. The South Coast Air Quality Management District (SCAQMD) directed our client to remove, transport, and dispose of all excavated soil to disposal facilities. We negotiated with the SCAQMD to develop a plan to implement an alternative approach, where we agreed to follow all health and safety measures to protect the workers and the public and to remove two to four USTs per day to minimize potential air emission losses into the atmosphere; contain the impacted soil for backfilling; install a horizontal soil vapor extraction network in the bottom of the excavation; and connect the network to an extraction system to remove the VOCs from any impacted soil beneath the site. Implementation of the above approach eliminated short-term liabilities associated with the transport of contaminated soil and long-term liability of disposal. After five meetings with the SCAQMD, we obtained the agency's approval and saved approximately $450,000 for our client.

Deep Soil Removal And Compaction

Inglewood, California

We were retained by Southern California Edison (SCE) to excavate environmentally impacted soil at a site in Inglewood, California, to a depth of 82 feet below grade and compact the area to a level that would be suitable for future construction. The area of interest was close to aboveground structures and streets; therefore, there was no access to open excavation. Our evaluation showed that shoring was cost-prohibitive. We prepared a plan to use large-diameter augers to excavate the soil. SCE and the SCAQMD approved the plan. We used 3-foot and 5-foot diameter augers to drill to a depth of 82 feet below grade. We tested the soil to ensure compliance with Rule 1166 of the SCAQMD. There was no sloughing during the excavation. Soil samples were collected throughout the entire depth for geotechnical and environmental testing. After reaching the target depth, we backfilled the borings using a cement-bentonite mix that was cured within 24 hours.

We drilled 98 boreholes to a depth of 82 feet using a Leapfrog approach and removed approximately 10,000 cubic yards of soil. We showed statistically that the concentrations of residual soils at the sidewalls meet the benzene concentration criteria. We prepared a report summarizing the scope of field activities and the geotechnical and environmental testing results. The fieldwork took approximately two months to complete. We complied with the SCAQMD permit requirements, and there were no permit violations and no complaints from the neighboring facilities.

Remedial Investigation/Feasibility Study
Chemical Distribution Facility, San Jose, California

We completed several phases of investigation to define the lateral and vertical extent of VOCs in soil and groundwater, to identify and evaluate viable mitigation alternatives, and to develop design parameters for the most appropriate remedial alternative. The investigations included installing and sampling 44 groundwater monitoring wells and drilling and sampling over 100 borings.

While investigations were underway to characterize the site fully, our personnel designed and implemented an interim remediation program to contain and remediate plumes of dissolved chlorinated VOCs, alcohols, ketones, and glycols in groundwater. To accomplish this objective, six extraction wells were installed in the shallow zone, and one extraction well was installed in the underlying aquifer. A combined air stripping/bio-oxidation system was used to treat the VOC-containing groundwater. To prevent off-site migration, we installed a hydraulic barrier and extraction wells and demonstrated the complete on-site containment of the plume. After two years, our evaluation showed that there was no longer a need to treat the oxygenated compounds, and the removal of the bio-oxidation unit saved more than $150,000 per year.

RI/FS, Pilot Testing, Ground Water Extraction, and Risk Assessment

Fillmore Fish Hatchery, Fillmore, California

The facility was operating as a fish hatchery under the jurisdiction of the Department of Fish and Game. The facility used 3,000 gpm of groundwater to remain operational. Three 500-gallon USTs were maintained at the site to store diesel fuel and gasoline. Following tank removal activities, TPH-g and BTEX were detected in soil and groundwater at the site. Groundwater was observed at two feet below the ground surface (bgs).

Rubicon conducted a feasibility study to identify and evaluate viable remedial alternatives. Excavation of the impacted soil and groundwater was among the alternatives for further evaluation. Rubicon conducted a soil excavation pilot test, which was terminated due to shallow groundwater and the collapse of pit side walls.

Groundwater extraction pilot testing was performed to determine if groundwater extraction could be effectively applied at the site. Discussions between the Ventura County Environmental Health Department (VCEHD), RESD, DFG, Fillmore Fish Hatchery, and Rubicon determined that groundwater extraction would continue for a set period and the effectiveness would be monitored. Pursuant to the recommendations of the meeting participants, Rubicon resumed groundwater extraction. A total of 38,779 gallons of water were pumped from the shallow zone. Concentration reduction was observed in all extraction wells.

Rubicon utilized data from the extraction to perform risk assessment and concluded that the termination of remedial measures would not threaten human health or the environment. Instead, Rubicon prepared a risk management plan to implement when the site is ready for renovation/modification. Rubicon requested that the VCEHD issue a no further action letter. The VCEHD responded that the site is eligible for low-risk case closure. VCEHD sent the file to the California Regional Water Quality Control Board, Los Angeles Region (LARWQCB), which subsequently confirmed VCEHD's decision. All groundwater monitoring wells were abandoned.

Feasibility Evaluation of a Ground Water Recharge Basin

Orange County Water District, Anaheim, California

The demand for the construction of groundwater recharge basins and the discovery of nearby contaminated sites pose a great challenge for groundwater managers and water resource professionals. Rubicon performed a comprehensive analysis of groundwater flow and contaminant transport for a proposed groundwater recharge basin near the impacted site. We constructed a three-dimensional numerical model to quantitatively assess the effects of the proposed recharge on the PCE plume. The flow model domain covered an area of 1.9 miles by 3.5 miles within the Orange County Groundwater Basin. It included the contaminated site, two flood control basins, and active groundwater extraction and production wells. Simulated hydrologic zones within the Orange County Basin include the Shallow Aquifer, Principal Aquifer, and Deep Aquifer. These aquifers and the intervening aquitards were represented by 17 layers in the model. The groundwater flow model conforms to the characteristics of the flow regime in the surrounding Orange County Ground Water Basin. MODFLOW and MT3DMS were used to perform the groundwater flow and contaminant transport modeling, respectively.

Rubicon calibrated the flow model against the regional water levels of the Shallow and Principal aquifers and the local groundwater conditions of the contaminated site. Production wells located within the flow domain and extraction wells of the impacted site were included in the flow model. Basin recharge rates were varied over time to reflect recorded historical values. The groundwater recharge for the proposed basin was assumed to begin in 2006. Three transport simulations were performed, one without any recharge and two with 4,500 and 9,000 acre-feet per year recharge. Using the existing PCE concentrations and plume configuration, the transport model was calibrated to match the historical data. Contaminant transport simulations were performed for the period extending from January 1988, when the Shallow aquifer became impacted by PCE, to 2016. Advection, dispersion, and retardation were included in the transport model.

The modeling results showed that the proposed recharge activities will not have an adverse effect on the PCE concentration and will not significantly change the direction of PCE plume movement. Model results also demonstrated that PCE concentrations in the Principal Aquifer decrease over time, particularly under two recharge scenarios. To confirm model predictions and monitor groundwater conditions during future operation of the recharge basin, Rubicon developed a monitoring program that includes certain existing monitoring wells and several new wells to be installed at strategic locations.

Extraction Line Installation and Testing

Commerce, California

Rubicon designed obtained a permit, and installed more than 2,000 feet of soil vapor and groundwater extraction lines to connect dual-phase extraction wells to a treatment system compound. Rubicon installed three vaults to facilitate the installation and testing of the gas lines and used a backhoe to excavate 18-inch wide by 3-foot deep trenches to install the piping network. The trenches were then backfilled with six inches of sand prior to placing the 6-inch diameter Schedule 80 PVC pipes. We pressure-tested the lines to check for leaks and then backfilled the trenches with six inches of sand, six inches of pea gravel, and approximately one foot of clean imported soil. The soil was compacted to a minimum relative density of 95 percent.

The vapor extraction network includes the three vaults mentioned above, through which the conveyance piping is passed. In one location, the piping passes below a street, and in a second location, the piping crosses below railroad tracks. The jack-and-core approach was used for construction under the railroad spur.

One vault is located on either side of the rail crossing. To install the piping below the railroad, a 20-inch diameter conductor casing was installed using jack-and-bore techniques. The network includes three moisture knockouts at low points to collect condensate from the vapor lines. Each of the three moisture knockouts is equipped with a submersible pump and a float switch for automatic on/off operation to transfer the condensate to the treatment system compound. All vapor conveyance piping is under vacuum. The work was inspected and approved by the Southern California Gas Company.

Cost Allocation/Litigation Support

Burbank/Glendale Operable Unit San Fernando Valley, California

The USEPA had identified solvent-impacted groundwater in the San Fernando Valley, California, in areas designated as Burbank OU and Glendale North and South OUs. The USEPA directed the PRPs to develop a single regional remedy and decide among themselves the contribution of each party to the total cost of the remedy. The presumptive remedy for the OUs was pump-and-treat. Rubicon was retained by an electronics manufacturing company located near the downgradient edge of the plume and was named as one of the major contributors to the final remedy cost. The case involved more than 45 PRPs with facilities located from Burbank to the southern end of Glendale. An arbitration panel was selected to hear various approaches and strategies for a two-phase cost allocation. The first phase would collectively decide the relative contributions from Burbank sources versus Glendale sources. The second phase pertained to allocating responsibility among the PRPs within the Glendale North and South OUs. We evaluated each facility's environmental conditions and constructed a plume analysis model from which the contribution of each PRP could be estimated. Based on these modeling results and other considerations, the arbitration panel concluded that Burbank sources had contributed to 58.2 percent of the groundwater contamination. In comparison, all Glendale sources were responsible for the remaining 41.8 percent. The allocated cost to the electronic manufacturing party we represented was significantly less than the original allocation amount.

Facility Owner v. Insurance Carriers Wood Preserving Facility Ukiah, California

Rubicon was charged with conducting the remedial investigation and feasibility study for a wood-preserving facility in Ukiah, California, listed as a Superfund site by the USEPA. Our services included characterization of the groundwater flow regime, delineation of the extent of contamination, and development of remedial actions. The chemicals of concern included hexavalent chromium, arsenic, and copper. The owner of the wood-preserving facility also retained us to evaluate chromium spill characteristics and render an opinion on the nature of release, quantity of discharge, transport in surface runoff, infiltration into the subsurface, adsorption on the soil particles, and migration into the underlying groundwater. The purpose of this litigation support was to recover the cost of remediation from the insurance companies that had issued policies during the facility's operation. The case was settled in favor of the owner.

RWQCB v Owner Wood Preserving Operation Turlock, California

Pursuant to the requirements of a Remedial Action Order issued by the California Department of Health Services and an Administrative Consent Order issued by the USEPA, Rubicon performed soil and groundwater investigations at a former wood preserving facility in Turlock, California. The objective was to delineate the extent of hexavalent chromium contamination and develop a remedial action plan.

Our activities also included a review of regional geology, drilling, and sampling of more than 120 borings, installation and monitoring of over 50 groundwater monitoring wells, groundwater sampling, aquifer tests, off-site installation of several deep water supply wells for neighboring landowners whose domestic wells were threatened by hexavalent chromium migrating from the site, geochemical studies, risk assessment, evaluation of remedial alternatives, and bench-scale/pilot-scale tests. Potential issues of concern included spillage of chromium solution, on-site contamination of soil/groundwater, threat to downgradient water supply wells, and delays in remedial response.

The owner was cited for non-compliance and violation of hazardous waste laws. We represented the owner and provided details of tasks, associated timelines, and rationale for perceived delays. The case was settled out of court.

Adaptive Project Management

Fish Hatchery

At a fish hatchery where 3,000 gallons of water per minute passed through the system, petroleum hydrocarbons were detected in the soil and groundwater. We performed a feasibility study of remedial options and selected two remedies: Excavation and pump-and-treat. We implemented both options, but residual contaminants persisted. We performed a risk assessment and demonstrated that the groundwater and the ecological environment will not be impacted. We prepared a risk management plan and recommended mitigating the conditions at the time when site restoration is needed in order not to interfere with the operations of the fish hatchery. We negotiated the plan with the Ventura County Department of Environmental Health (VCDEH) and the California Department of General Services (DGS). The two agencies accepted the plan for implementation.

SGMA

The 2014 California's Sustainable Groundwater Management Act (SGMA) requires all groundwater basins to be managed sustainably by 2040-2042. The SGMA provided a framework for forming Groundwater Sustainability Agencies (GSAs), the authorities enforcing SGMA on local communities and water purveyors. GSAs were tasked with developing Groundwater Sustainability Plans (GSPs) by 2020-2022 and are expected to execute them within the 20-year implementation period. The State of California Department of Water Resources (DWR) and the State Water Resources Control Board are the lead agencies that provide grants and directions to the GSAs and develop guidelines for developing GSPs and their implementation.

2022, The Year of GSP Implementation

GSPs are planning documents defining the actions required to manage a basin sustainably. A complete GSP includes a hydrogeological conceptual model (HCM) that establishes the current basin settings and conditions; an evaluation of SGMA's six sustainability indicators (SGMA defines six undesirable results: chronic lowering of groundwater levels, reduction of groundwater storage, seawater intrusion, land subsidence, water quality degradation, and depletions of interconnected surface water); current and projection of water budget; a list of management actions and projects for achieving sustainability; and financial impacts and resources of the GSP implementation. In summary, a GSP is a basin's roadmap to sustainability when the amount of produced groundwater from aquifers is recharged naturally or artificially.

Mineral Oil Recovery and Groundwater remediation Westminster, California

Since 1996, Rubicon has been the primary environmental consultant for Southern California Edison for on-call environmental site investigation and remediation services. We have conducted numerous investigations for various SCE residential, commercial, and industrial facilities throughout California. Most investigations included soil, soil gas, surface water, stormwater, and groundwater sampling, and if warranted subsequent with remedial activities. Rubicon is an extended wing of SCE’s Waste Management and Remediation Program and has reputed as a trusting and reliable partner among SCE project managers. Rubicon projects for SCE encompass most aspects of environmental engineering and remediation and include:

Cumulative Mineral Oil Recovery during Remediation at Westminster Service Center

Diesel plome at the UST Area

Rubicon has performed an extensive investigation and remediation of soil and groundwater conditions that resulted from the use and leakage from aboveground (AST) and underground (UST) fuel storage tanks at the PVID maintenance facility. Rubicon's activities at the site included: Installation of 52 groundwater monitoring wells; implementation of “pump & treat” system, including 11 extraction wells for remediation of groundwater; recovery of 6,000 gallons of free product as diesel and fuel; conducting semi-annual groundwater monitoring and preparation of reports; corresponding and negotiating with the Colorado River Basin Regional Water Quality Control Board (CRB Water Board); obtaining closure and no-further-action letters for the facility; and conducting risk assessment and soil excavation to remove all residual contamination in the soil. The facility consisted of three areas that had USTs and ASTs. Rubicon had already obtained closure for two areas of the Site. The Water Board accepted Rubicon's approach for closure of the third and final area and agreed to issue closure for the ASTs provided PVID abandons all existing wells. Rubicon abandoned the wells in January 2021 and PVID received closure in February 2021. The PVID trusted Rubicon for over the years with their environmental challenges, solely because of our integrity, cost-effectiveness measures, and delivery of high-quality services. It is important to mention that our modeling convinced the CRB Water Board to provide closure even though we currently have diesel concentrations in groundwater. We demonstrated that the downgradient water supply wells will not be affected and therefore the residual concentrations are not a threat to environment and human health.

Trenching and Excavating Underground Storage Tanks at a Chemical Distribution Facility

Rubicon conducted four phases of RFI and several interim remedial measures at the facility including preparation of RFI work plans, SAP, QAPP, data management plan, and HASP; performed drilling and soil sampling at 95 locations to a depth of 125 feet; installed 40 groundwater monitoring wells to a maximum depth of 260 feet; performed aquifer testing, soil gas surveys, and indoor air/ambient air sampling and analysis including modeling using Johnson & Ettinger modeling software; characterized the hydrogeology under the site; prepared a comprehensive, quantitative risk assessment; conducted indoor air sampling and analysis; developed a numerical groundwater/chemical transport model; performed quarterly groundwater monitoring and prepared quarterly reports; developed and executed public participation plans; developed Community Profiles and fact sheets; managed waste disposal; and developed interim remedial actions.

Interim soil remediation included the removal of USTs, ASTs, and clarifiers, and soil vapor extraction (SVE). Rubicon has performed operations, maintenance, troubleshooting, and monitoring of the remediation systems which have included an SVE system featuring a granular activated carbon (GAC) unit with a catalytic oxidation unit and eight dual phase extraction (DPE) wells for soil and groundwater remediation. The system recovered approximately 55,000 pounds of VOCs before it was dismantled in March 2011 to allow for construction of the dual-phase groundwater remedial measures.

Rubicon completed the remediation design and implementation in 2013. The remediation system is still operating and is maintained by the facility’s staff.

Five underground storage tanks (UST) containing gasoline and waste oil were removed from the City of Alhambra’s Maintenance Yard in the 1990s. However, the soil in the area was not evaluated for the presence of residual contamination. The LA Water Board on April 20, 2018 sent a Corrective Order Letter to the City. That order requested additional assessments to be conducted and work plan for these activities must have been submitted to the LA Water Board by May 20, 2018. After Rubicon was contacted by the City’s Utility Department’s Deputy Director, Mr. David Dolphin, we initiated developing the work plan and submitted to the agency by the requested deadline before even an agreement was executed between Rubicon and the City (executed on August 27, 2018). The LA Water Board approved Rubicon’s work plan and requested the results of the investigation in a technical report format by October 13, 2018. We completed all pre-field activities and hired the most qualified with best value subcontractors in September and mobilized our field crew on October 1, 2019. For this project, Rubicon:

Drilled a total of 12 borings using Direct Push Technology (DPT) to a depth of 35 feet below ground surface and collected samples at every five-foot interval;
Analyzed the samples using a mobile laboratory for total petroleum hydrocarbons (TPH) and volatile organic compounds;
Showed, based on the results of this investigation, that the removal of the USTs was conducted properly, and that no residual contamination is present at the site; and

On October 12, 2018 Rubicon Submitted the final Site Closure Report and requested closure for the site from the LA Water Board based on application of the State Low-threat Closure Policy. On October 7, 2019, the Water Board issued a no-further-action letter and approved Rubicon’s request for Site Closure. The City was delighted with Rubicon’s efforts to finish this project within the budget in a timely manner. This project is an indication of Rubicon’s ability to complete fast-paced projects with short notice and limited time.