When determining optimal sve well placement, radius of influence is considered. The unit includes a 205l knockout drum and carbon scrub system. 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. Soil vapor extraction system optimization, transition, and. The influence of surface covers on the performance of a. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to sve optimization, transition, andor closure. The performance of an sve system depends on properties. Guidance for design, installation and operation of soil. Oct 02, 2019 well, installing and operating a pilot scale sveas system, data collection, system design and reporting.
In 1998, a vacuum truck was used to remove the product from the wells. Effective oxygen, in situ air sparging, radius of influence, soil. The sve system controls vapor plume migration by creating a negative pressure in the unsaturated zone through a series of extraction wells. To calculate the effective radius of the dewatering wellpoint configuration. Appendix e radius of influence design calculations appendix f threedimensional air flow modeling appendix g sve shutdown protocol memorandum. Sve system optimization, but has limited information related to approaches for sve closure and meeting remediation goals. Air sparging radius of influence the design of an effective air sparging system requires data beyond the normal contaminant and geological information. Pore gas velocity analysis showed that when the cover clay layer was used, the zone of capture of the soil vapor extraction system increased. Indeed, the ease with which sve systems can be installed and operated belies the very complex nature of subsur face vapor behavior and transport. The current sve system will be reconfigured into two separate sve systems. Incorporating pv drains in an sve system can extend the.
Additional vews are being considered for the sve system. Soil vapor extraction sve is a physical treatment process for in situ remediation of volatile contaminants in vadose zone unsaturated soils epa, 2012. 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. Soil vapor extraction and bioventing table of contents subject parag r aph pag e chapter 1 introduction. Pdf soil vapor extraction of chlorinated solvents at an industrial. However, the product returned to monitor wells outside the radius of influence of the sve system. Extraction wells and monitoring points the existing sve well sve1 was used as the extraction point for the pilot test.
This corrective action plan cap describes activities to remediate groundwater. It is primarily a radius of influence roi test bed however it can also be used to treat hydrocarbon impacted soils. Measure sve system offgas voc concentrations for fullscale design air permitting purposes. Roi radius radii of influence sim selected ion method sve soil vapor extraction. The computer model was also used to develop intrinsic soil permeability estimates. Air sparging system used alone, the sve system cannot remove contaminants in the saturated below the water table zone figure 11. 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. Soil vapour extraction unit sve200 the sve200 is an integrated blower set constructed on a robust metal pallet. 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. Figure 3 shows the sve system and the location of the vews, including the estimated radius of. Tceq pst cap worksheets soil vapor extraction sve tceq. Avoid radius of influence approach consider air throughput. Roi radius radii of influence sim selected ion method sve soil vapor extraction trg target remediation goal gl micrograms per liter usepa u.
Monitor groundwater for water levels, water quality, and natural attenuation parameters. The radius of influence with respect to vapour extraction determined from the pilot test. 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. Determine the effective radius of influence roi for the fullscale system design. Documents for design and construction of svebv systems.
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. Environmental protection agency voc volatile organic constituentcompound. The system is ideal for well point or trench type vapor barriers. Air spargeair spargespargeand sve system for treatment and sve system for treatment of vocs, svocs, and arsenic authors. 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.
Air sparging is an attractive remediation technology because, like sve, it is relatively simple to implement and. Geosierra has pioneered the use of hydraulic fracturing of low permeable soils to enhance soil vapor extraction sve. Soil vapour extraction unit sve200 the remediation group. Pages 22 through 24 in the guidance discuss the considerations that should be used for well spacing. Vapor intrusion mitigation with horizontal directional drilling. A conceptual layout of the system as shown in figure 1 includes nine sparging points and two sve wells. Soil vapor extraction pilot test summary and phase i. If water table is shallow, water vapor entrained into sve system can be a problem, especially due to system freezing. Tabulated system and blower curves533 table 51c pneumatic analysis for sve system. Therefore, sve can remove nearly all gasoline constituents, a portion of kerosene and diesel fuel constituents, and a lesser portion of heating oil constituents. Prepare a conceptual design for a sveas system on the eastern portion of the site2 process description 3.
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. How to evaluate alternative cleanup technologies for. The radius of influence of a combined method of in situ. If off gas treatment is required, contact geotech for information on air treatment equipment. Soil vapor extraction and bioventing united states army. Fracture enhanced sve significantly reduces the cost and time to remediate tight soil formations. Vapor extraction, air sparging minnesota pollution control. Vapor intrusion mitigation with horizontal directional. These studies suggest that effective number of wells and their placement should be based on the air flow field created near the wells. Kale novalis, nadira najib, omer uppal, matthew ambrusch, annie lee, stewart abrams, p. Because the radius of influence is less than ft the distance to the nearest contaminant plume, the dewatering plan.
The radius of influence of a combined method of in situ air sparging. H screen length of extraction well l p atm atmospheric pressure 1 atm p well absolute pressure at extraction well atm. Please add information on the importance of roi and why it is important. Using an air flow simulationoptimization model is therefore an attractive tool for obtaining. 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. Obtain design data needed to size the sve blower and efficiently design and configure sve wells for the fullscale system.
The sve system will include an air injection ai component. 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. System modeling and design the results of the field test will be used to determine effective radius of influence and this. Has the radius of influence roi been calculated for each soil type at the site. Soil vapor extraction pilot test summary and phase i system. This full scale design proposal may be submitted in conjunction with the pilot test report or may be submitted as a rap. 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. Pilot test results summary pet and extended pe results.
Datawill also aid in determining timeframe for site closure. The design radius of influence is 15 ft with a design flow rate of 27 cubic ft per minute cfm. 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. 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.
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. Tceq pst cap worksheets dual phase extraction dpe tceq. Is the blower selected appropriate for the site conditions. 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. Knowing such parameters allows one to delineate, on the field, a protec tion area around a pumping well. Kirtland air force base, albuquerque, new mexico 5. The radius of influence of a combined method of in situ air. The sve was removed from service in 1995 due to an apparent lack of freephase petroleum product. When used in combination with soil vapor extraction sve, air bubbles carry vapor phase contaminants to a sve system which removes them. Conduct a focused site assessment to evaluate other potential site sources or chemicals of potential concem copcs. Installing horizontal sand filled fractures in these soils significantly increases the soil mass permeability and greatly enhances the radius of influence. Cost and performance summary report soil vapor extraction. 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. Vmp to assess the b360 sve system radius of influence roi.
Much of the technical information re garding the design, construction, and op eration of an extraction. Cost and performance summary report soil vapor extraction and. The current pce concentrations and roi results are superimposed on top of the pce historical. In general, constituents in petroleum products with boiling points less than 250e to 300ec are sufficiently volatile to be amenable to removal by sve. 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. The estimated time for fullscale remediation of the site is 2 years. Soil vapor extraction technology reference handbook. The most common soil vapor extraction applications are at underground storage tank sites, usually gasoline stations. Radius of influence is the maximum distance from an sve well that still provides sufficient pressure gradient to induce flow of contaminants. Tight soils are not amenable to conventional sve due to their low permeability. Soil type min diameter mm max diameter mm k min md k max md min discharge. Is the proposed well density appropriate, given the total area to be cleaned up and the radius of influence for each well. Defining the air sparging radius of influence for groundwater. 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.
A total of 74 sve wells will be configured so that they can be operated in an ai mode. 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 sve system will be operated in one of the two target soil layers at a given time. 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. An roi is expressed as a circle centered around the injection or extraction wells and thus, the radius of this circle denotes the roi epa 2004. 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. Sve the sve system was started in may 2001 and consisted of five 12foot vapor extraction wells vew. 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 roi and pv exchange rate are used to determine the fullscale sve well spacing. This manual is approved for public release, distribution is unlimited. 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. From a practical point of view, it is important to know the average aquifer size influ.
Collect laboratory vapor samples to estimate the discharge and potential treatment andor permitting requirements. Guidance for design, installation and operation of soil venting systems, through august 11, 1995 page 2. 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. Seasonal fluctuations of the water table will not allow continuous operation in the lower silty sand layer. Some simple procedures for the calculation of the influence. 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. 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. Soil vapor extraction and bioventing usace publications army. Optimal flow rates and well locations for soil vapor.
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