Radius of influence is the maximum distance from an sve well that still provides sufficient pressure gradient to induce flow of contaminants. Yes no yes no yes no no radius of influence roi is one of the main factors that needs to be evaluated to design an sve system. Optimal flow rates and well locations for soil vapor. The sve was removed from service in 1995 due to an apparent lack of freephase petroleum product. This full scale design proposal may be submitted in conjunction with the pilot test report or may be submitted as a rap. Soil vapor extraction and bioventing usace publications army. Pore gas velocity analysis showed that when the cover clay layer was used, the zone of capture of the soil vapor extraction system increased. System modeling and design the results of the field test will be used to determine effective radius of influence and this. It is primarily a radius of influence roi test bed however it can also be used to treat hydrocarbon impacted soils. How to evaluate alternative cleanup technologies for. Using air sparging as an sve enhancement technology increases. If water table is shallow, water vapor entrained into sve system can be a problem, especially due to system freezing. In the design stage, the roi can be varied according to several factors comprising the physicochemical properties of soils, humidity, and times required for the remediation of corresponding. The most common soil vapor extraction applications are at underground storage tank sites, usually gasoline stations.
When used in combination with soil vapor extraction sve, air bubbles carry vapor phase contaminants to a sve system which removes them. The performance of an sve system depends on properties. A total of 74 sve wells will be configured so that they can be operated in an ai mode. Soil type min diameter mm max diameter mm k min md k max md min discharge. Obtain design data needed to size the sve blower and efficiently design and configure sve wells for the fullscale system. Appendix e radius of influence design calculations appendix f threedimensional air flow modeling appendix g sve shutdown protocol memorandum. Vmp to assess the b360 sve system radius of influence roi. The radius of influence of a combined method of in situ. Soil vapor extraction sve is a physical treatment process for in situ remediation of volatile contaminants in vadose zone unsaturated soils epa, 2012.
The roi and pv exchange rate are used to determine the fullscale sve well spacing. Tceq pst cap worksheets dual phase extraction dpe tceq. Much of the technical information re garding the design, construction, and op eration of an extraction. In general, constituents in petroleum products with boiling points less than 250e to 300ec are sufficiently volatile to be amenable to removal by sve. Fracture enhanced sve significantly reduces the cost and time to remediate tight soil formations. The computer model was also used to develop intrinsic soil permeability estimates. Soil vapour extraction unit sve200 the sve200 is an integrated blower set constructed on a robust metal pallet. Please add information on the importance of roi and why it is important. Geosierra has pioneered the use of hydraulic fracturing of low permeable soils to enhance soil vapor extraction sve. H screen length of extraction well l p atm atmospheric pressure 1 atm p well absolute pressure at extraction well atm. When as is combined with sve, the sve system creates a negative pressure in the unsaturated zone through a series of extraction wells to control the vapor plume migration. Remedial design and implementation technical guide april 2012 iv introduction many forms and types of remedial technologies exist in eth world and each has its. The unit includes a 205l knockout drum and carbon scrub system.
Avoid radius of influence approach consider air throughput. Cost and performance summary report soil vapor extraction and. Datawill also aid in determining timeframe for site closure. Conduct a focused site assessment to evaluate other potential site sources or chemicals of potential concem copcs. Defining the air sparging radius of influence for groundwater. Documents for design and construction of svebv systems. Kale novalis, nadira najib, omer uppal, matthew ambrusch, annie lee, stewart abrams, p. Jun 08, 2016 as part of the vapor intrusion management program, horizontal sve wells were strategically installed in the vadose zone and thin gravel layer beneath the building slab to actively mitigate vapors. The radius of influence with respect to vapour extraction determined from the pilot test. However, after sve operation, this conceptual model should be revisited in the context of defining the current conditions, using the data compiled during sve operations and any additional data as needed to support optimization, transition, and closure decisions. Indeed, the ease with which sve systems can be installed and operated belies the very complex nature of subsur face vapor behavior and transport. Extraction wells and monitoring points the existing sve well sve1 was used as the extraction point for the pilot test. Additional vews are being considered for the sve system. Soil vapor extraction technology reference handbook.
These studies suggest that effective number of wells and their placement should be based on the air flow field created near the wells. Seasonal fluctuations of the water table will not allow continuous operation in the lower silty sand layer. The sve system will include an air injection ai component. If off gas treatment is required, contact geotech for information on air treatment equipment. The estimated time for fullscale remediation of the site is 2 years. Soil vapor extraction and bioventing united states army. Air sparging radius of influence the design of an effective air sparging system requires data beyond the normal contaminant and geological information. Is the blower selected appropriate for the site conditions.
Oct 02, 2019 well, installing and operating a pilot scale sveas system, data collection, system design and reporting. Aug 22, 2016 radius of influence roi an roi refers to the maximum distance enabling the flow of air to be injected or extracted through injection or extraction wells. The radius of influence of a combined method of in situ air sparging. Therefore, sve can remove nearly all gasoline constituents, a portion of kerosene and diesel fuel constituents, and a lesser portion of heating oil constituents. Scoping documents work plan for sve system upgrade 11. Soil vapor extraction pilot test summary and phase i system. Air spargeair spargespargeand sve system for treatment and sve system for treatment of vocs, svocs, and arsenic authors. The system is ideal for well point or trench type vapor barriers. Environmental protection agency voc volatile organic constituentcompound.
From a practical point of view, it is important to know the average aquifer size influ. Us army corps of engineers engineering and design em 111014001 3 june 2002 soil vapor extraction and bioventing this manual is approved for public release, distribution is unlimited. Sve also referred to as in situ soil venting or vacuum extraction is based on mass transfer of contaminant from the solid sorbed and liquid aqueous or nonaqueous phases into the gas. Figure 3 shows the sve system and the location of the vews, including the estimated radius of. Kirtland air force base, albuquerque, new mexico 5. Soil vapor extraction system optimization, transition, and. Guidance for design, installation and operation of soil. The current pce concentrations and roi results are superimposed on top of the pce historical. The radius of influence of a combined method of in situ air. Sve the sve system was started in may 2001 and consisted of five 12foot vapor extraction wells vew. Air sparging is an attractive remediation technology because, like sve, it is relatively simple to implement and. Soil vapor extraction pilot test summary and phase i. The sve system s roi was compared to soil contamination data to determine if the sve system is adequately addressing the known sources of contamination. The design radius of influence is 15 ft with a design flow rate of 27 cubic ft per minute cfm.
Soil vapor extraction sve x x x o o o x x o o x x x x x e vsdxecxnaxh eny l l amreht x ox ooo ooo x o x x o x xxvb xgnxi xt nooxevo ib x x o oox ox x o x. Design consideration for sve soil vacuum causes water table to rise, reducing thickness of unsaturated zone if water table is shallow, water vapor entrained into sve system can be a problem, especially due to system freezing in winter surface cap is needed to reduce entrainment of clean air from the atmosphere. Monitor groundwater for water levels, water quality, and natural attenuation parameters. The current sve system will be reconfigured into two separate sve systems. Some simple procedures for the calculation of the influence.
Work plan introduction 12 final august 2006 reconfiguring the sve piping for the aoc65 sve system to eliminate condensate blockage that has affected system performance. Vapor intrusion mitigation with horizontal directional drilling. This corrective action plan cap describes activities to remediate groundwater. Vapor intrusion mitigation with horizontal directional. The sve system controls vapor plume migration by creating a negative pressure in the unsaturated zone through a series of extraction wells. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to sve optimization, transition, andor closure. Soil vapor extraction and bioventing table of contents subject parag r aph pag e chapter 1 introduction. Sve also referred to as in situ soil venting or vacuum extraction is based on mass transfer of contaminant from the solid sorbed and liquid aqueous or nonaqueous phases into the gas phase, with subsequent collection of the gas phase. This manual is approved for public release, distribution is unlimited. Guidance for design, installation and operation of soil venting systems, through august 11, 1995 page 2. The radius of influence with respect to groundwater removal determined from the pilot test data ranged from 22 m to 29 m for shallow pumping and 30 m to 34 m for deep pumping. Pilot test results summary pet and extended pe results.
Cost and performance summary report soil vapor extraction. When air sparging is combined with sve, the sve system creates a negative pressure in the unsaturated zone through a series of extraction wells to control the vapor plume migration. In 1998, a vacuum truck was used to remove the product from the wells. To calculate the effective radius of the dewatering wellpoint configuration. Measure sve system offgas voc concentrations for fullscale design air permitting purposes. One of the most important parameters in a system design is the radius of influence roi of both the sparging wells and the sve wells. Incorporating pv drains in an sve system can extend the. The sve system will be operated in one of the two target soil layers at a given time. When determining optimal sve well placement, radius of influence is considered. Pdf soil vapor extraction of chlorinated solvents at an industrial. Tight soils are not amenable to conventional sve due to their low permeability. Vapor extraction, air sparging minnesota pollution control. However, the test will be continued for as long as necessary to ensure collection of the required data and sufficiently to evaluate the effectiveness of sve as a remedial technique for this site. Roi radius radii of influence sim selected ion method sve soil vapor extraction trg target remediation goal gl micrograms per liter usepa u.
However, the product returned to monitor wells outside the radius of influence of the sve system. The influence of surface covers on the performance of a. This layout is based on an assumed radius of influence of 20 ft for the air sparging wells and 50 ft for the sve wells which in our experience is typically achieved using standard design variables. Subject terms sve, soil vapor extraction, remediation, site characterization, optimization 16. I think it would be useful for you to add a sentence or two on the use of sve in combination with other technologies.
The radius of influence of soil vapor extraction sve systems, based on the attainment of a critical vacuum or pore gas velocity, can then be increased by including a surface seal in the design of such. Installing horizontal sand filled fractures in these soils significantly increases the soil mass permeability and greatly enhances the radius of influence of the sve extraction wells. Yes no yes no yes no no system creates a negative pressure in the unsaturated zone through a series of extraction wells to control the vapor plume migration. As part of the vapor intrusion management program, horizontal sve wells were strategically installed in the vadose zone and thin gravel layer beneath the building slab to actively mitigate vapors. Roi radius radii of influence sim selected ion method sve soil vapor extraction. Effective oxygen, in situ air sparging, radius of influence, soil. The radius of oxygen transference is the maximum distance of the transference of oxygen in air injected through injection wells for biological degradation of contaminants. A conceptual layout of the system as shown in figure 1 includes nine sparging points and two sve wells. Tceq pst cap worksheets soil vapor extraction sve tceq. These tasks are designed to gain further knowledge regarding the expected radius of influence of a sveai system that may be used to mitigate the petroleum release at the project site. Has the radius of influence roi been calculated for each soil type at the site. Soil vapour extraction unit sve200 the remediation group.
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