Environmental Engineering
In the last four decades, we have been providing environmental engineering services to the private and public sector clients. Our environmental investigation services range from due diligence and initial site assessment to detailed hydrogeologic characterization; delineation of chemical constituents in soil vapor, soil, and groundwater; risk assessment; groundwater flow and chemical transport modeling; vapor intrusion studies; geochemical assessment; and soil gas and groundwater monitoring and reporting. We perform these services within the frameworks of the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Underground Storage Tank programs or the local regulatory agency guidelines. The primary purpose of environmental investigation is to define the extent of contamination and potential impact on the environment and ground water. We have conducted these characterizations for chemical distribution facilities; chemical and paint manufacturing facilities; electronic, aerospace, petroleum, and wood preserving facilities; and utility facilities; as well as for developers, financial institutions, and the legal community. Once the site is characterized, we perform feasibility studies to screen and evaluate various remedial options and then select the most appropriate option for client and agency approval prior to implementation. Rubicon then designs, permits, and installs the remediation system followed by operation and maintenance (O&M) and system optimization. We have implemented these services at many Superfund sites. Over the years, we have established credibility with the federal, state, and local regulatory agencies helping our clients to achieve closure cost-effectively.
Environmental Investigation
In the last four decades, we have been providing environmental engineering services to private and public sector clients. Our services range from due diligence and initial site assessment to detailed hydrogeologic characterization; delineation of chemical constituents in soil vapor, soil, and groundwater; risk assessment; groundwater flow and chemical transport modeling; vapor intrusion studies; geochemical assessment; and soil gas and groundwater monitoring and reporting. These characterizations are generally performed within the frameworks of the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Underground Storage Tank programs, or the local regulatory agency guidelines. The primary purpose of site characterization is to define the extent of contamination and potential impact on the environment and groundwater. We have conducted these characterizations for chemical distribution facilities, chemical and paint manufacturing facilities, electronic, aerospace, petroleum, and wood preserving facilities, and utility facilities, as well as for developers, financial institutions, and the legal community.
Environmental Remediation
Once the site is characterized, we perform feasibility studies to screen and evaluate various remedial options, and then select the most appropriate option for client and agency approval prior to implementation. Rubicon then designs, permits, and installs the remediation system, followed by operation and maintenance (O&M) and system optimization.
Rubicon has designed, implemented, or evaluated most, if not all, of the much soil and groundwater remediation technologies commonly used today. Some of Rubicon’s remediation systems have been in operation for over 25 years. This in-depth, hands-on experience enables Rubicon to understand the advantages and limitations of the various available remediation technologies and their application to a given site conditions.
When preliminary assessments confirm the presence of contamination in the environment, the appropriate remedial approach must be implemented to clean up the contaminated site. A risk assessment is often conducted to identify potential pathways for the contaminant to reach the human body and surrounding environment. If the risk assessment warrants remediation, a site-specific focused feasibility study is required to 1) develop a conceptual site model, which effectively characterizes the site hydrogeology and sensitive receptors; 2) evaluate available and applicable remedial options based on the type and extent of contamination; and 3) select the most efficient and practical remedy, which will remediate the site to the regulatory standards. After the selection of the remedy, an engineering team will design the system for construction and implementation. The remediation systems must be maintained to maximize the recovery and equipment lifespan.
Some of the proven and innovative remedial technologies we have implemented for soil vapor, soil, and groundwater are as follows:
- No action
- Risk management
- Soil vapor extraction
- Containment technologies (Slurry walls, sheet piles, and grout curtains).
- Soil excavation
- Chemical fixation/stabilization
- Biodegradation
- Air stripping
- Pump-and-Treat
- Dual-phase extraction
- In-situ chemical oxidation
- Monitored natural attenuation
- Advanced oxidation
- Electrochemical treatment
Contaminant Transport Modeling
As one of the pioneers in groundwater flow and chemical transport modeling, Rubicon has the expertise and is equipped with the latest state-of-the-art software to develop and assess the migration of chemical contaminants through groundwater flow.
To understand the behavior of contaminants in soil and groundwater, Rubicon resorts to a phased modeling approach. Initially, simplified models are utilized because there is usually insufficient input data. Examples of simplified models include RESSQ and TDAST. RESSQ is used to track contaminant pathways and to test extraction/injection scenarios. TDAST is used to estimate the migration behavior of contaminants and gain insight into their behavior under various environmental conditions. As the site is characterized, the models become more complex and accurate representatives of the site conditions. An essential utilization of models is to design and analytically test remedial systems.
Rubicon also utilizes models to assess the allocation of responsibility and cost to multiple potentially responsible parties (PRPs) who may have contributed to a commingled contamination plume. Factors contributing to the complexity of allocation cases include the potential migration of VOCs from various upgradient facilities, different times of release, and estimation of credits to the PRPs that may have performed extensive remediation. We have applied the models to predict the response of the aquifer(s) to various hydrologic stresses, including extraction and injection; develop water management alternatives; predict the migration of contaminants under local/regional and stressed conditions; design remediation systems and test various remedial scenarios; identify sources of contaminants in commingled plume situations; and cost allocation among potentially responsible parties.
Some of our recent or ongoing modeling projects are as follows:
- Numerical simulation of a hydraulic barrier to contain TCE and Freon-impacted groundwater at a site in Huntington Beach, California, for system design and future site evaluation.
- Numerical simulation of in-situ chemical oxidation to mitigate VOC-impacted soil and groundwater at a site in southern California; design of well spacing and amendment dose.
- Numerical simulation of migration of VOCs at a site adjacent to San Diego Bay to evaluate the potential impact on the Bay's water quality and to design and optimize the remediation system.
- Evaluation of groundwater recharge and potential impact on spreading the existing contaminants using MODFLOW and RT3D.
Groundwater Flow and Chemical Transport Modeling
As one of the pioneers in groundwater flow and chemical transport modeling, Rubicon has the expertise and is equipped with the latest state-of-the-technology codes to simulate site-specific hydrogeologic and contaminant transport models. Modeling the flow of water and the transport of chemical constituents is a common and proven tool to understand and predict the behavior of soil-water systems. With recent advances in software and hardware, modeling has become an integral component of most environmental and water resource projects. In modeling groundwater flow and chemical transport, we adopt a phased approach. Our initial modeling efforts begin with the application of simplified codes based on data availability and time/budget constraints. Computationally, these models are generally analytic or semi-analytic and may have limitations to simulating large-scale problems. As additional data is developed and the system is further characterized, more sophisticated numerical models are utilized to represent the system of interest accurately.
This phased approach has proven to be the most cost-effective way of applying appropriate models for solving practical problems. Our modeling experience allows us to understand the principal assumptions, develop proper formulations, and apply appropriate codes for achieving specific modeling objectives. We have applied the models to predict the response of the aquifer(s) to various hydrologic stresses, including extraction and injection; develop water management alternatives; predict the migration of contaminants under local/regional and stressed conditions; design remediation systems and test various remedial scenarios; and identify sources of contaminants in commingled plume situations.
Rubicon also utilizes models to allocate responsibility and cost to multiple potentially responsible parties (PRPs) who may have contributed to a commingled contamination plume. These allocations are based primarily on the volume of the water treated and the mass of contaminants removed. Factors contributing to the complexity of allocation cases include the potential migration of VOCs from various upgradient facilities, different release times, and estimation of credits to the PRPs that may have performed extensive remediation.