Grabbing Attention with Remediation Innovation
As environmental pollution becomes a pressing issue, innovative solutions are essential to restore contaminated areas. One such solution is In Situ Thermal Remediation (ISTR), combining Gas Thermal Remediation and Thermal Conduction Heating (GTRTM and TCH). This advanced technique was utilized recently at a site in the Port of Los Angeles to address Non-Aqueous Phase Liquids (NAPLs) and Volatile Organic Compounds (VOCs). This post explores the project's detailed execution, hurdles, outcomes, and the technologies that contributed to its success.
Thermal Remediation Project Overview
The Port of Los Angeles project targeted an area of about 1,237.5 square feet, with depths extending up to 43 feet underground. The main goal was the effective removal of NAPLs and VOCs, known for their potential harm to both human health and the environment.
Treatment Approaches
To tackle the contamination, the project utilized a combination of treatment methods:
Thermal Conduction Heating (TCH): Heating the subsurface soil to approximately 120˚C was crucial. This temperature allowed contaminants to be released from the soil, effectively aiding in their removal.
Multi-Phase Extraction (MPE): MPE was employed to simultaneously extract both liquid and vapor contaminants. This enhanced effectiveness led to faster recovery of pollutants.
Soil Vapor Extraction (SVE): Implemented alongside TCH, SVE was responsible for pulling VOCs from the soil, thus improving air quality on and around the site.
C3™ Vapor Abatement Technology: This innovative system was vital in capturing and treating vapors generated during the thermal process, ensuring minimal release into the environment.
By integrating these technologies, the project team aimed to comprehensively address subsurface contamination and facilitate environmental restoration.
Wells Configuration
The well field for the project included:
18 TCH Heater Wells: Strategically placed to ensure even heating throughout the treatment area, optimizing contaminant removal.
6 Co-Located MPE/SVE Wells: These allowed the simultaneous extraction of liquid and vapor, enhancing recovery efficiency.
4 Shallow SVE (sSVE) Wells: Additional sSVE wells specifically targeted surface contaminant vapors for effective capture.
Monitoring Points: Eight temperature and two pressure monitoring points were established to oversee the conditions during remediation, ensuring both safety and treatment performance.
Significant Remediation Outcomes
The project's results highlighted the effectiveness of the chosen methodologies, demonstrating quantifiable success. A total of 6,081 pounds of contaminants were extracted from the target area. The specifics include:
6,041 Pounds of NAPLs: Captured in a chemical storage tank, showcasing the system's ability to handle dense and persistent pollutants.
32 Pounds of VOCs: Reduced through the Vapor-Phase Granular Activated Carbon (VGAC) system, illustrating significant improvements in air quality.
12 Pounds of Diesel: Isolated in the sludge at the bottom of the weir, this recovery added to the project’s overall effectiveness.
Liquid Produced: Approximately 234,666 gallons of liquid were generated, adhering to environmental regulations by discharging into the Los Angeles Sanitation sewer system.
The successful extraction not only mitigated the immediate dangers presented by NAPLs and VOCs but also paved the path for further environmental health restoration in the Port of Los Angeles.
Treatment Area Insights
Location and Geological Features
The remediation site in San Pedro, CA, is recognized for distinctive geological attributes. The area's composition included silty sand, poorly graded sand with shells, silt, and clay. These characteristics presented specific challenges during the thermal remediation process, necessitating careful planning.
Primary Contaminants
The main contaminants targeted were NAPLs and VOCs. NAPLs consist of heavy hydrocarbons that can linger in the environment, posing considerable risks. In contrast, VOCs are organic chemicals that can quickly evaporate, contributing to air pollution. Thus, their effective remediation is essential.
Key Treatment Conditions
The thermal remediation system was designed with strategically placed heater wells, maintaining target temperatures of around 120˚C throughout the 137.5-day treatment period. Such controlled conditions maximized contaminant recovery while safeguarding the surrounding environment.
Implementation Steps and Strategy
The implementation of the In Situ Thermal Remediation project involved several vital steps:
Site Evaluation: Thorough investigations assessed the extent of contamination, lithology characteristics, and associated risks.
System Design and Setup: Based on evaluation findings, the thermal remediation system was constructed, ensuring optimal well and monitoring point placement.
Heating Phase: TCH was initiated, raising subsurface temperatures to the target level, facilitating the release and extraction of contaminants.
Extraction Processes: Continuous monitoring of thermal and vapor pressures enabled adjustments during extraction activities, maximizing pollutant recovery.
Post-Remediation Evaluation: After completing the heating and extraction phases, the site was re-evaluated to assess the effectiveness of remediation efforts, which indicated substantial reductions in contaminant levels.
Final Thoughts on Environmental Revival
The successful application of In Situ Thermal Remediation at the Port of Los Angeles sets a powerful example of how advanced technologies can effectively manage subsurface contamination. The extraction of 6,081 pounds of NAPLs and significant VOC reductions showcases the capabilities and potential of these methods.
As environmental challenges grow, the importance of innovative remediation technologies like ISTR becomes clear. The lessons learned from this case highlight the necessity of innovation, thorough planning, and diligent execution in effectively addressing environmental issues.
By combining advancements in thermal remediation with strategic planning, we can achieve successful restorations and have a lasting positive impact on public health and the environment. The future of environmental remediation lies in ongoing exploration and investment, ensuring the safety of our environments for generations to come.
Comments