EBS uses a variety of laboratory analysis and equipment to solve complex environmental challenges. The EBS Principal Scientist, James A. Jacobs, has over 35 years of experience as a geologist. He is a certified hydrogeologist and professional geologist. He has co-authored five environmental science technical books and is a Fulbright Scholar, with 4 Fulbright Senior Specialists awards. Below are three examples of a wide range of different environmental presentations featuring science-based solutions: one is on bioremediation and remediation management zones to obtain case closure, the second presentation relates to the removal of heavy oil free product using a flushing, extraction and infusion process. and third presentation is focused on a community services district with the goal increasing sustainability, reducing landfill waste, and lowering groundwater contamination.
CLEANUP PLANNING AND DESIGN USING REMEDIATION MANAGEMENT ZONES: OZONE WITH ENHANCED BIOREMEDIATION CASE STUDY
James Jacobs and Roger Brewer
The fragmented approach for remediation planning often involves sequential remediation in different treatment zones rather than long-term planning using a comprehensive simultaneous remediation design in order to obtain site closure. One way to handle the simultaneous remediation approach is using Environmental Hazard Evaluation (EHE). EHE includes the subsurface investigation phase and is based on the use of pre-approved, comprehensive, Environmental Screening Levels (ESLs, referred to as action levels or EALs in some states). The site investigation is designed to identify the presence or absence of each hazard on the basis of applicable ESLs, not simply define the vertical and lateral extent and magnitude of soil and groundwater contamination. This comprehensive approach helps avoid the need for time-consuming and costly remobilization for additional sampling in the future. In addition, it addresses the common concern from regulators that although the lithologic and chemical data have been collected, the site closure request has not been justified.
The results of the EHE are used to prepare site Environmental Hazard maps that depict areas where soil and groundwater contamination pose specific environmental hazards. This is carried out by comparing soil, groundwater, and, in some cases, soil gas data to detailed ESLs for specific environmental hazards. Maps that collectively summarize areas of the site where specific environmental hazards are present are then prepared (i.e., based on a review of all contaminants of concern) and site conceptual models are prepared as well as potential exposure pathways. The hazard maps are then used with the results of the site investigation to divide contaminated areas into three Remediation Management Zones: Zone 1 (source zone: aggressive treatment to remove priority environmental hazards), Zone 2 (residual zone: passive treatment to address intermediate priority hazards), and Zone 3 (attenuation zone: monitoring to ensure contamination is not spreading). Specific environmental hazards associated with each zone are clearly identified from the start of the project (direct exposure, vapor intrusion, leaching, etc.). The zone boundaries are either ESLs applicable to the targeted hazards or the treatment limits of particular remedial technologies. A San Francisco, California site will be examined where Remediation Management Zones were used in the planning and design phase of the project. Ozone was used in Zone 1 and enhanced bioremediation using oxygen infusion was used in Zone 2. The current status of this project will be discussed.
Presenter: James A. Jacobs, P.G., C.H.G., Environmental Bio-Systems, Inc., 707 View Point Road, Mill Valley, CA 94941; Telephone: 415-381-5195; firstname.lastname@example.org
Roger Brewer, Ph.D., Hawai’i Department of Health, Hazard Evaluation and Emergency Response, 919 Ala Moana Boulevard, Honolulu, HI 96816, Telephone: 808-586-4328; email@example.com
FREE PRODUCT REMOVAL OF DIESEL-RANGE HYDROCARBONS USING A 3 STEP FLUSHING, EXTRACTION AND INFUSION PROCESS
James A. Jacobs
A three-step flushing, extraction and infusion process has been developed for removal of free product (hydrocarbons and chlorinated solvents). Flushing was performed at a former tank pit at a northern California site containing heavy oil-range hydrocarbons that were trapped beneath the saturated zone. Flushing uses a two-step flushing process which includes high-pressure air injection and biosolvent injection to thin and mobilize diesel-range or heavier hydrocarbons, which was measured up to 41 cm in height in one well on one site. The high-pressure air injection and biosolvents were used with dual phase extraction to recover both the heavy oil and the biosolvent.
At another site, biosolvent flushing was performed followed by a Supersaturated Water Injection (SWI) technology with carbon dioxide saturated water injection. SWI allowed for controlled mobilization of petroleum hydrocarbons into the water table for collection using dual phase extraction. SWI technology relies on water which is supersaturated with carbon dioxide using a mass transfer system. The saturated water is injected under high pressure into the former tank pit where carbon dioxide bubbles nucleate at the targeted area of the aquifer. The rising carbon dioxide bubbles contact with the submerged diesel-range hydrocarbons in the saturated zone and cause volatilization of the free product into the vapor phase and mobilization of NAPL trapped in the pores.
Several extraction wells and dozens of small-diameter reinjection ports were used to recirculate the carbon dioxide saturated water and provide a closely-spaced delivery and extraction system. The carbon dioxide is distributed by flowing water resulting in effective carbon dioxide distribution followed by heterogeneous bubble nucleation and continuous growth of gas bubbles in situ. A gas saturation front developed which expanded laterally and vertically towards the water table in the former underground tank pit. Diesel-range hydrocarbons mobilize to soil gas and are extracted with a dual phase extraction system. Case studies will be described. After the carbon dioxide SWI process, a similar SWI process using oxygen is used to flood the saturated remediation area with oxygen for enhanced bioremediation.
A MODEL OF ENVIRONMENTAL SUSTAINABILITY FOR MANAGING RESOURCES, MINIMIZING WASTES AND REDUCING GROUNDWATER CONTAMINATION AT A CALIFORNIA COMMUNITY SERVICE DISTRICT
James A. Jacobs and Jon Elam
A green business model was developed for the Tamalpais Community Services District (TCSD), located in unincorporated Mill Valley, California. The agency performs solid waste, sewer collection and Park and Recreation services for 2,550 households. With an annual budget of $4.3 million (2008-9), TCSD focuses on managing resources and protecting groundwater and surface water, while also collecting waste. In the process of providing collection services, savings related to energy use and landfill diversion were noted. In 5 years, landfill garbage has been reduced 20% and recycling and green waste (turned into mulch) has increased by 33%. TCSD recycled more than 1,304 tons of paper, cardboard and plastics.
TCSD will collect 100 lbs of used and outdated medicines in 2009. In prior years these pharmaceutical wastes were likely dropped into toilets and released into surface waters after standard wastewater treatment or placed in the refuse containers and deposited in the landfill where the these unregulated chemicals could leach into groundwater. Other recycling programs have diverted 3 tons of electronic wastes (TVs, microwaves, computers) per year from landfills. In 2008, battery drop-off collection saved about 1,000 lbs heavy metals, mostly lead and cadmium as well as battery from leaching into the landfill groundwater. Over12 months, 600 compact fluorescent light bulbs (CFLs) and 480 fluorescent lamps containing 3.0 Kg and 5.8 Kg of mercury, respectively, will be recycled and diverted from the landfill. Between 2005 and 2008, garbage collection was reduced from 2,300 to 1,900 tons, a savings of 800,000 lbs of waste not filling local landfills.
The Mill Valley area served by TCSD lies at sea level on Richardson Bay a part of the greater San Francisco Bay. Due to two tidally influenced creeks, groundwater within about 1 mile of the shoreline is usually encountered within 3 feet of ground surface. Most of the flatland in the valley was originally bay marsh, and significant subsidence occurred over the past 50 years on the residential structures, roads as well as the sewer laterals and main pipelines, causing significant wet weather inflow and infiltration. TCSD has reduced wet weather flows to it’s two nearby wastewater treatment plants by 10% by reducing infiltration and inflow and by repairing numerous broken sewer laterals and mains. One set of sewer repairs has reduced wet weather flow to one wastewater plant by 40%. With less pumping of storm water and shallow groundwater, energy consumption was reduced by 20% in 2008 from 2006. The focus on environmental sustainability has lead to a waste collections program which saves money, environmental resources and generates broad community support.
Authors: James A. Jacobs, PG, CHG, is a board member of TCSD and Chief Hydrogeologist with Environmental Bio-Systems, Inc., 707 View Point Road, Mill Valley, CA 94491; Tel: 415-381-5195; firstname.lastname@example.org, www.ebsinfo.com
Jon Elam was the General Manager of TCSD, 305 Bell Lane, Mill Valley, CA 94941. He retired fro TCSD in 2017.
Enhanced bioremediation uses an understanding of site specific geochemistry and naturally occurring microbial processes to optimize site conditions. Enhanced bioremediation improves the environmental conditions for the microbial degradation of specific contaminants by adding an electron acceptor such as oxygen, which is frequently the limiting factor of the natural process.
The oxygen accepts the electron as part of the microbial cellular respiration process. The photo above shows crude oil being degraded by aerobic microbes in a laboratory cell culture dish.
Enhanced bioremediation relies on general availability of naturally occurring microbes to consume contaminants as a food source (petroleum hydrocarbons in aerobic processes) or as an electron acceptor (chlorinated solvents). In addition to microbes being present, in order to be successful, these processes require nutrients (Carbon: Nitrogen: Phosphorus equals 100:10:2 or 100:10:1). EBS evaluates geochemical and redox conditions in aquifers as well as microbial counts for biofeasibility studies (aerobic, anaerobic, and co-metabolic). EBS will perform nutrient calculations as well as provide the design and liquids for site-specific nutrient mixes. Sometimes, the microbes necessary to provide exude the proper enzymes are not present in volumes capable of reasonable degradation rates. In those cases, EBS works with laboratories to develop microbe cultures for specific contaminants, such as MTBE, PCE, TCE and other compounds.
Laboratory Bench Scale Services
Commonly overlooked, bench testing provides some of the most important site-specific information about the likelihood of success or failure of an in situ remediation project. EBS performed dozens of bench tests for in situ chemical oxidation (ISCO) (bench tests for Fenton's Reagent, permanganate, persulfate, ozone, and others), enhanced bioremediation (microbiological feasibility studies and microcosm studies) and metals stabilization for numerous consulting companies. These tests are a way to optimize reactant chemistry in the laboratory rather than in the field. In addition, EBS provides bench tests for process treatments for environmental equipment to verify successful results and proper designs.
In-Situ Chemical Oxidation
EBS designs and implements a variety of in situ chemical oxidation (ISCO) processes for soil and groundwater remediation. EBS designs and provides field oversight for the high-pressure injection of liquid or solid chemical oxidants such as the hydroxyl radical (Fenton's Reagent), hydrogen peroxide, persulfate, potassium, sodium and calcium permanganate, percarbonate, and persulfate to greatly accelerate the complete destruction of petroleum hydrocarbons, chlorinated solvents, MTBE, BTEX, PCBs, PCPs and other organic chemicals. Delivery pressures for liquid oxidants include well and filter gallery trenches (30 to 40 psi), moderate pressure injection rods (200 to 600 psi) to high pressure (3,000 to 5,000 psi) lances. Ozone, a gas, is also used for in-situ remediation in a variety of delivery systems. EBS oversees the installation of the oxidants with proprietary injection and pumping technologies in specialized sparge points or treatment trenches. Ozone can be injected at low pressure (less than 15 psi) or higher line pressures (40 to 75 psi) for in situ applications. Safety design is an important element of any EBS-designed injection project.
• Groundwater Modeling services
• Design Considerations For In-Situ Chemical Oxidation Using High Pressure Jetting
• In-Situ Chemical Oxidation Using Jetting Delivery
• List of organisms destroyed by Chemical Oxidation
Ozone Treatment Packages
Ozone (O3) is a powerful gas phase oxidizer that can be used to treat volatile organic compounds. Ozone must be generated on-site and the gas cannot be stored; therefore all the ozone gas that is generated must be injected into the subsurface or destroyed using an ozone destruction unit on the ozone generator. The ozone gas can be bubbled into closely spaced injection ports that release the bubbles into the aquifer for remediation. The smaller the bubbles, the more surface area and the faster they can travel through small pore spaces. Pumping the ozone gas through specially designed ozone diffusers can produce micro-bubbles. Advanced oxidation processes refer to when ozone is catalyzed or enhanced by ultra violet light, hydrogen peroxide or other oxidizers, to increase the power of the ozone by producing more hydroxyl radicals. Treatability testing in the laboratory can evaluate the cost benefit of the different ozone enhancements prior to mobilizing into the field.
In-Situ Metals Geochemical Fixation or Stabilization
EBS designs and injects liquid and gas reducing agents to immobilize toxic soluble metals such as lead, arsenic, chromium (VI) also called “hexavalent chromium”, cadmium, nickel and other metals using geochemical fixation. The treated metals become insoluble in the process, reducing the need for expensive excavation and disposal. EBS uses sulfur dioxide (gas) as well as the following liquids: calcium polysulfide, sodium metabisulfite and ferrous sulfate in a proprietary jetting technology. Safety design is an important element of any EBS designed injection project.
• Metals Stabilization Using Geochemical Fixation
• PowerPoint - Hexavalent Chromium Remediation (click screen to advance presentation)
• Chromium (VI) Handbook
• Chromium (VI) Attenuation Study
EBS does not sell remediation equipment, except for the inVentures Technologies, Inc. gas infusion equipment. Other companies, such as Remediation Shop www.remediationshop.com sell a variety of remedial equipment and license remedial processes. For more information, please contact: Kevin Pope, 800-794-1789). Remediation Shop installs and distributes a variety of groundwater and treatment water and soil remedial equipment such as ozone generators, thermal oxidizers, oil water separators, emulsion-splitting plants, evaporators, equipment and chemical storage, sewer treatment discharge plants, car/truck wash systems, industrial wash wastewater recycling systems, advanced oxidation systems, fluidized bed bioreactors, and grease treatment systems.
EBS works with consultants who work with small wineries (<30,000 cases per year) and larger ones who are required to meet water treatment goals for waste water used in the wine making process and equipment washing process. Until relatively recently, this segment of industry has not seen much regulatory oversight, however, water regulators are now focusing on wineries. This water typically has 3,000 to 5,000 mg/L biological oxygen demand (BOD). EBS has developed a modular approach that is flexible for wineries as well as cost effective for discharge to land through irrigation or discharge to a sanitary sewer. Typical waste discharge requirements for discharges of winery waste are available in the link below.
• Winery Discharge Requirements
EBS provides bench testing, field testing as well as the designs and oversight for the field implementation by others of a variety of remedial processes.
• Cold Mix Asphalt Process for soils and sludges (for metals, hydrocarbons, solvents and pesticides); and
• High Pressure Biosolvent Flushing Process for Groundwater (for heavy oils, diesel, motor oil, crude oil,
hydraulic oil, PCBs, PAHs).
Soil and Sludge Recycling Process
Cold mix asphalt (CMA) is a remedial process that recycles sludges and soils contaminated with petroleum hydrocarbons, heavy metals, chlorinated solvents and pesticides/herbicides into a useful product: asphalt. The asphalt can be stored for 6 months or more, and can be used for parking lots, bike paths, hiking trails, berms and other uses.
COLD MIX ASPHALT
Free Product Removal Technologies
EBS has developed or worked with two in-situ free product removal processes that are performed by others, in which EBS provides technical oversight. These include the High Pressure Biosolvent Flushing Process and the CO2 Saturated Water Injection Process.
High Pressure Biosolvent Flushing Process
In the laboratory, an environmental-friendly biosolvent for the removal of heavy to moderate weight petroleum hydrocarbons, such as diesel, motor oil, hydraulic oil, PCBs and crude oil has been developed. It has been approved by the US EPA for use in off-shore and river oil spills. EBS uses environmentally friendly, naturally occurring surfactants for acceleration of in-situ remediation of free product (both hydrocarbon and chlorinated solvents). By generating micro-droplets, the free product is broken down from one large liquid area into billions of micro-droplets. This transformation increases in surface area, allowing for more rapid degradation by both chemical oxidation and enhanced bioremediation.
TYPES OF PROJECTS
Since 1989, EBS has worked on hundreds of small and large projects in the following industries or settings:
• EBS projects are usually brought in by consultants, working on a variety of settings, including many industries, including the refining and distribution of petroleum and oils, dry cleaners, transportation, marine transportation companies and rental companies as well as public sector owners such as cities, counties, the Federal government, including the military.
• Types of Properties: EBS has worked on projects at manufacturing, industrial and commercial properties, for owners and consultants whose clients represent both the private and public sectors.