STRATEGIES FOR LNAPL REMEDIATION

Transcription

1 STRATEGIES FOR LNAPL REMEDIATION J. D. Keetley Petroleum Storage Tank Trust Fund Utah Department of Environmental Quality 2011 ASTSWMO LUST and State Funds Workshop September 13-15, 2011 Chicago, Illinois

2 40 CFR Free Product Removal 1988 Maximum extent practicable Implementing agency Minimize spread Hydrogeological conditions at the site Abate free product migration

3 EPA 510-R (1996)

4 How to Effectively Remove Free Product at LUST Sites: A Guide for State Regulators Engineered systems Page IV-2 Only a portion of the free product will be recoverable Even under ideal conditions A significant proportion will remain in the subsurface as immobile residue

5 Why is it hard to remove LNAPL from subsurface soils? LNAPL Ganglia in Soil 1.5 millimeters

6 Dr. Kamaljit Singh Non-aqueous phase liquids (NAPLs) in porous media Three-dimensional volume rendering of various phases at residual NAPL saturation: water (blue) and NAPL ganglia (yellow)

7 Conditions Affecting Thickness of LNAPL in Wells From API Publication No.18, May 2003

8 Tools in the Arsenal The Usual Tools Hydraulic Removal Hand bailing Vacuum trucks Skimming & pumping systems Excavation & Dewatering Multi-Phase Extraction Air Sparging & Vapor Extraction

9 Surfactants Tools in the Arsenal Newfangled Tools Electrical Resistance Heating Natural Source Zone Depletion Environmental Covenants CO2-Supersaturated Water Injection & Vapor Extraction

10 Excavation and Dewatering

11 Dewatering during Excavation

12 Multi-Phase Extraction

13 7-Eleven, Salt Lake City

14 Air Sparging & Soil Vapor Extraction

15 Hydraulic Removal: Hand Bailing and Sorbent Socks Is it worth it?

16 An Alternative to Consider Vac Truck Consultant measuring free product recharge

17 Free Product Recharge Test using a Vac Truck Wiles Oil LUST Site (MW-11) Date Depth to FP (ft bgs) Depth to GW (ft bgs) FP Thickness (ft) : All FP removed (58 gallons water and 4 gallons FP). Well recharged to 1.1 ft thickness in 30 minutes

18 Hydraulic Removal Sunrise Market, La Verkin, Utah

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20 Hydraulic Removal Summary How much free product can you get out? How much will you leave behind? What is the maximum extent practicable?

21 Hydraulic Removal Summary How much hydraulically recoverable free product is in the subsurface? Vertical equilibrium concepts - ITRC LNAPL Web-based training and classroom training LNAPL Transmissivity (Tn) - starting or ending performance metric

22 ITRC and LNAPL Transmissivity

23 ITRC LNAPL Transmissivity as a Performance Metric

24 ASTM Workgroup WK26425 New Standard Guide for Evaluating LNAPL Transmissivity (Draft form) - Draft form

25 LNAPL LUST Trust Site Hal s Service, Green River, Utah

26 Extent of Mobile LNAPL 1990/1991 Hal s Service Street 450 feet Main Street (Hwy 191) Horizontal Wells Ray s Tavern Street Ray s Tavern

27 Extent of Mobile LNAPL 1990/1991 PID Reading SILTY CLAY & Mobile LNAPL Residual LNAPL SAND Green dots w/numbers = PID readings (ppm-v) 450 feet

28 Hal s Service Estimating LNAPL 1995: Contacted the Utah State University, Water Research Laboratory ARMOS Model: (Areal Multiphase Organic Simulator) Values ranged from 46,000 to 306,000 gallons of LNAPL (average of 129,000 gals LNAPL) Skimming had removed about as much as it effectively could (16,000/129,000 = 12%) The LNAPL body considered stable and will not migrate any farther

29 1999: Horizontal wells Hal s Service 2003: Multi-Phase Extraction (MPE) pilot test 16, , ,000 = 23,000 gallons 23,000/129,000 = 18% removed 82% left in the ground Have we removed free product to the maximum extent practicable?

30 Environmental Covenants Utah DEQ Interactive Map Hal s Service

31 Environmental Covenant Hal s Service, Green River, Utah

32 Surfactants Definition of Surfactant: (from surface-active agent) -- a substance, such as a detergent, that can reduce the surface tension of a liquid and thus allow it to foam or penetrate solids; a wetting agent.

33 Surfactants There are two schools of thought on the application of surfactants to remove free product: 1. Dump & Vac Water 2. Vac, Dump, & Vac LNAPL We are experimenting with both methods. Soil

34 Surfactants - Dump & Vac Method Meadow Gold Dairy, Salt Lake City, Utah Vac Truck removing surfactant solution + diesel emulsion

35 Surfactants Vac, Dump, & Vac Method Big O Tires, St. George, Utah

36 Surfactants Vac, Dump, & Vac Method Big O Tires, St. George, Utah

37 Surfactants Vac, Dump, & Vac Method Big O Tires, St. George, Utah EcoVac

38 Guaranteed Fixed Price Closure of Leaking UST Sites *Average Cost/Duration: $287,000 for 1/3-acre plume in 4 months Project Location Remediation Dates *Duration Process Geology *Plume Size *Cost Trucking Facility Oklahoma City, OK Oct 24 to Nov 16, months SURFAC Very Fine grained sand Diesel Fuel 80 by 70 by 8 $225,850 Former Gasoline Retail/ Convenience Store, Del City, OK Jan 23 to Mar 14, months SURFAC Silty clay interbedded w/ clayey silt Gasoline 200 by 175 by 10 $548,100 Former Gasoline Retail/ Convenience Store, Yukon, OK May 13 to Jun 17, months SURFAC Silty clay interbedded w/ clayey silt Gasoline 200 by 70 by 7 $225,000 Former Texaco Station El Reno, OK Jul 14 to 31, month SURFAC Silty clay interbedded w/ clayey silt Gasoline 120 by 60 by 8 $70,000 Active Truck Fueling Facility Marietta, OK Jun 18 to Jul 31, months SURFAC Silty Clay Diesel Fuel 60 by 60 by 5 $183,000 Active Gasoline Retail/ Convenience Store, Cromwell, OK Aug 11 to Oct 1, months SURFAC Sandstone Gasoline 240 by 120 by 8 $450,700 Active Gasoline Retail/ Convenience Store, Norman, OK Nov 17 to Dec 11, months SURFAC Very Fine grained sand Gasoline 200 by 70 by 8 $219,500 Former Gasoline Retail/Convenience Store, Oklahoma City, OK Apr 7 to May 3, 2008 Jun 18 to Jul 10, 2008; Jan. 5 to 8, months SURFAC ISCO-EFR Silty clay interbedded w/ clayey silt Gasoline 250 by 190 by 6 $574,000 Former Gasoline Retail/ Convenience Store, Jenks, OK Feb 23 to Mar 5, months SURFAC ISCO-EFR Very Fine grained sand Gas/Diesel Fuel 100 by 75 by 10 $148,200 Active Gasoline Retail/ Convenience Store, Lawton, OK Mar 10 to 24, 2009; Nov. 5 to 27, months SURFAC ISCO-EFR Sandy clay with interbedded clay Gasoline 12,500 sq. feet $163,500 Active Fuel Distribution Facility Oklahoma City, OK Mar 11 to Apr 24, months SURFAC Siltstone/Sandstone Gasoline 100 by 80 by 10 $180,500

39 Electrical Resistance Heating From Wikipedia: Electrical resistance heating (ERH) is an intensive in- situ environmental remediation method that uses the flow of alternating current electricity to heat soil and groundwater and evaporate contaminants. Electric current is passed through a targeted soil volume between subsurface electrode elements. Ask Jeff Kuhn (MT) or Steve Reuter (NM).

40 Natural Source Zone Depletion

41 CO2-Supersaturated Water Injection

42 CO2-Supersaturated Water Injection

43 CO2-Supersaturated Water Injection & Vapor Extraction Express Mart 2729 West 9000 South Salt Lake City, Utah

44 CO2-Supersaturated Water Injection Express Mart 2729 West 9000 South Salt Lake City, Utah

45 CO2-Supersaturated Water Injection Express Mart 2729 West 9000 South Salt Lake City, Utah

46 LNAPL REMEDIATION The End Photo courtesy of Dr. Roger Brewer, Hawaii DOH