BlOTROL'•••• ••••BC; > for environmental solutions, naturally!

July 17, 1991

Ms. Lisa NicholsEPA Region IIIMail Code 3 HW 21841 Chestnut BldgPhiladelphia PA 19107

RE: Removal of chlorinated solvents from soil.

Dear Ms. Nichols:

Thank you for your interest in BioTrol's site remediation services.Dennis Chilcote of our Chaska Minnesota office requested that Isend you information regarding our RE-BOX system for soiltreatment.

RE-BOX design and operation specifications typically depend on thetype of contaminant, soil volume, and porosity. If contaminantsare volatile and biodegradable, for example, the RE-BOX isengineered as an aerobic bioremediation process and stripping unit.Biodegradation is enhanced by the controlled addition of inorganicnutrients, water, and atmospheric oxygen to overcome rate-limitingdeficiencies and stimulate microbial degradation of contaminantswhile a moderate air flow rate through the pile is maintained toenhance contaminant removal via air stripping. Operation of theunit can favor biodegradation or stripping depending on thevolatility and biodegradability of the contaminant.

BioTrol's standard RE-BOX has the following characteristics.Modifications are typically made on a case by case basis.

* arrayed as a treatment cell cluster (i.e., one to fourtreatment cells per unit;

* lined (with sumps), bermed, and covered for exposurepathway control;

BioTrol, Inc. • 210 Carnegie Center, Suite 101 • Princeton, Ml 08540(609) 951 -0314 • Fax (609) 951 -0316

MN Headquarters • Toll free 1-800-875-2468 /Ifi30ll j ft/IB/oTrol is an equal opportunity employer "* **

* - designed in a modular configuration for (1) expansionof the treatment cluster to accommodate additionaltreatment soil, (2) soil segregation during treatmentand (3) debris wash and water collection areas forsoil pretreatment;

I* loaded to a depth of 4 feet (2* feet subgrade 2 feet

above grade to maintain low profile);

* maintained at a slight negative pressure to controlvolatilization (contingency tr'eatment of VOCs isincluded in the design). : :

I •RE-BOX treatment of chlorinated solvents in soil will most likelybe attributed to stripping processes rather than to biodegradation.Process limitations may occur if soil has a' low porosity. Sometesting may be required prior to treatment design.

I would like to take this opportunity to further introduce myselfand the services and products available through BioTrol's PrincetonNew Jersey office. : .;

BioTrol is a remediation company specializing in biotreatment andsoil washing technologies. Products and services include thefollowing: ; :

1. Fixed Film Bioreactors for treatment of contaminated groundwateror industrial process water;

2. Soil Washing for volume reduction/pretreatment of contaminated(excavated) soil (feasibility testing, pilot 'demonstration at 500Ibs/hr, and full-scale treatment at 20 to 50 tons/hr);

3. Solvent Extraction for removal of PCB's (bench-scale feasibilitytesting, pilot demonstration, customized full-scale treatment);

4. Soil Recycling through biological treatment (landfarming orcontrolled aeration);

5. In-Situ Treatment of contaminated soil 4nd groundwater.

BioTrol, Inc. • 210 Carnegie Center, Suite 101 • Prinqstorl(609) 951-0314. Fax (609) 951-0316 ;

I have included some corporate brochures and fact sheets describingBioTrol's treatment technologies in greater detail. I would beglad to meet with you to discuss cost implications, system deliveryschedules, operation requirements, and performance expectations foreach treatment option. A presentation can also be arranged at yourrequest.

I look forward to discussing BioTrol's treatment capabilities withyou further. Please call me if you have any questions or wouldlike additional information.

Best regards,

BioTrol Inc.

Pamela SheehanEast Coast Regional Manager

cc< Dennis Chilcote, V.P. Engineering, BioTrol, Inc.

Enclosures: General Brochure Package

BioTrol, Inc. • 210 Carnegie Center, Suite 101 • Princeton, •«.«•«» A , -(609) 951 -0314 • Fax (609) 951 -0316 Hit$f$$1 §.2

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BlOTROC_*>"•?""•'• ... for environmental solutions, naturally!

BioTrol® Soil Washing Systemby

Steven B. Valine - Project ManagerDennis D. Chilcote - Vice President of Engineering

Technology Description

The BioTrol* Soil Washing System (U. S. Patent No. 4,923,125) is a water-based,volume reduction process for treating excavated soil. Soil washing is based on the premisethat: (1) contaminants tend to be concentrated in the fine size fraction of soil (silt, clay, andsoil organic matter), and (2) contaminants associated with the coarse soil fraction (sand andgravel) are primarily surficial. The objective of the process is to reduce the volume of soilthat requires" treatment by concentrating the contaminants in a smaller volume of materialwhile producing a washed soil product which meets appropriate clean-up criteria.

Following debris removal, soil is mixed with water and subjected to various unitoperations common to the mineral processing industry. Process steps can include mixingtrommels, pug mills, vibrating screens, froth flotation cells, attrition scrubbing machines,hydrocyclones, screw classifiers, and various dewatering operations.

Intensive scrubbing is the technology at the core of the process. For the gravelfraction, scrubbing is accomplished with a mixing trommel, pug mill, or ball mill. For thesand fraction, a multi-stage, counter-current, attrition scrubbing circuit with inter-stage classi-fication is used. This scrubbing action disintegrates soil aggregates, freeing contaminatedfine particles from the sand and gravel fraction. In addition, surficial contamination isremoved from the coarse fraction by the abrasive scouring action of the particles themselves.Contaminants may also be dissolved as dictated by solubility characteristics or partitioncoefficients.

These three mechanisms: (1) dispersion and separation of contaminated fine particles,(2) scouring of coarse particle surfaces, and (3) dissolution of contaminants each operate tovarying degrees, depending upon the characteristics of the soil and contaminant(s).

To improve the efficiency of soil washing, the process may include the use ofsurfactants, detergents, chelating agents, pH adjustment, or heat. In many cases however,water alone is sufficient to achieve the desired level of contaminant removal whileminimizing cost.

A significant reduction in the volume of material which requires additional treatmentor disposal is accomplished by separating the washed, coarse soil components from theprocess water and contaminated fine particles. A simplified flowsheet of the system is shownin Figure 1. r.-

BioTrol, Inc. • 11 Peavey Road • Chaska, Minnesota 55318 • 612/448-2515 • FAX 612/448-6050

BioTrol® Soil Washing System ! Page 2

The contaminated residual products can be treated by other methods. Process wateris normally recycled after biological or physical treatment. Options for the contaminatedfines can include off-site disposal, incineration, stabilization, or biological treatment.

MAKE-UP WATER

OPTIONS:

1. OFF-SITE DISPOSAL2. INCINERATION3. STABILIZATION4. BIODEGRADATION

Figure 1. Simplified Flowsheet - BioTrol* Soil Washing System (U. S. Patent No.4,923,125). :

ApplicabilityI II i

Soil washing systems can be tailored to remove both organic and inorganiccontaminants. Research by the U. S. Department of Energy and the U. S. EPA has alsoshown this technology to be directly applicable to radiologically contaminated soil.

For cases where the contaminants are associated principally with the fine size fraction,the amount of silt and clay, i.e., the weight of soil passing 74 microns (No. 200 sieve), shouldnot normally exceed 25 to 35 percent in order to achieve an economic volume reduction.The fraction of silt and clay in the soil may not be a factor when dissolution of contaminantsis the primary mechanism, i.e., the leaching of metals or soluble organics.

BioTrol, Inc. • 11 Peavey Road • Chaska. Minnesota 55318(612) 448-251 5 • I -800-875-2468 • Fax (612j 448-6050

i JUI300-I9S

BioTrol® Soil Washing System Page 3

Performance

BioTrol has conducted laboratory-scale testing with soil samples from numerouscontaminated sites. In general, organic contaminant levels in the washed soil are generally90 to 99 percent lower than in the feed soil. Removal efficiencies are dependent upon thecontaminant, the initial contaminant level, and the soil matrix. Typical testing results areprovided in Table 1. (The objective of tests shown below was to maximize organiccontaminant removal. Although removal efficiencies for metals was somewhat lower, thelevels achieved met customer requirements. If required, hydrometallurgical techniques canbe used to significantly improve metals removal.)

Table 1. Results of Laboratory Scale Testing - BioTrol* Soil Washing System

SiteDescription

Wood Preserving(California)

Wood Preserving(Florida)

Wood Preserving(North Carolina)

Chemical Plant(Michigan)

Wire Drawing(New Jersey)

Town Gas(Quebec)

PesticideFormulation(Colorado)

Contaminant

Total PAHs (1)ArsenicChromiumCopperZinc

PentachlorophenolPentachlorophenol

Total PAHs (1)Carcinogenic PAHs (1)ArsenicChromium

DichlorobenzidineBenzidineAzobenzene

TPH(2)VOC (3)CopperNickelSilver

Total PAHs (1)

ChlordaneAldrin4,4-DDTDieldrin

Before(mg/kg)

4800896329345

380610

10011289195

77010002400

47002.033011025

230

55472546

After(mg/kg)

230272313108

4.025

5.11.66451

136.07.0

3500.01100604.0

11

4.77.55.07.0

Reduction(percent)

9570635569

9996

95857874

9899

> 99

93> 99

704584

95

91848085

WashedSoil Weight

(percent)

83

9080

90

85

80

83

80

Notes: (1) Polynuclear aromatic hydrocarbons(2) Total petroleum hydrocarbons(3) Volatile organic compounds

BioTrol. Inc.* 1 I Peavey Road • Cnaika Minnesoro :J> '.-<: S(6121-448-251 5 • 1-800-875-2468 • Fax 16! 2\ 4-I3-605Q

II30i 196

BioTrol® Soil Washing System ; . Page 4!

Results ofEPA Superfund Innovative Technology Evaluation (SITE)i .',

The U. S. Environmental Protection Agency conducted an evaluation of BioTrol's soilwashing technology in the Superfund Innovative Technology Evaluation (SITE) programduring September and October of 1989. The MacGillis and Gibbs wood preserving site inNew Brighton, Minnesota was the location for the test. This Superfund site is contaminatedwith wood preserving wastes, including pentachlorophenol, creosote (polynuclear aromatichydrocarbons), petroleum hydrocarbons, and to a lesser degree, with arsenic, chromium, andcopper. ! :

A mobile, pilot-scale soil washing system with a nominal treatment capacity of 500to 1,000 pounds per hour was provided and operated by BioTrol during the demonstration.The system consisted of pilot-scale mineral processing equipment, including an automaticfeed system, a mixing trommel, vibrating screens, froth flotation cells, attrition scrubbingmachines, hydrocyclones, spiral classifiers, and dewatering equipment.

The capability of the system was evaluated by testing with two types of soil from thesite. The first sample was excavated from the vicinity of a former pole treatment tank anddesignated as the "low" contaminant level soil. A second sample, designated as the "high"contaminant level soil, was excavated from a "hot spot" in the site disposal area. Tests withthe "low" soil lasted two days while tests with the "high" soil lasted about 6 days. The soilwashing system operated 24 hours per day for both tests. Water alone was used for the test(no additives). i

Preliminary mass balance results are presented in Figure 2. As shown, 84 percent ofthe contaminated soil was recovered as washed soil. In addition to contaminated fines, thesoil contained 9 to 10 percent contaminated woody debris which was also separated in theprocess. ; "•

Washed Soil84.0%

/ Woody Debris: 9.5%

Contaminated Fines6.5%

Figure 2. Weight Distribution of Product Streams (Dry.Basis) - EPA SITE Program.

BioTrol. Inc. • I I Peavey Road • Cha.'ka. Minnesota 55318(61 2) 448-251 5 • 1 -800-875-2468 • Fax (612) 448-6G50

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BioTrol® Soil Washing System Page 5

Preliminary chemical analysis of the feed and washed soil are given in Table 2.Pentachlorophenol levels were reduced 91 to 93 percent in the washed soil compared to thefeed soil. Reductions in the level of total polynuclear aromatic hydrocarbons ranged from92 to 96 percent while reductions in total petroleum hydrocarbon levels ranged from 94 to95 percent.

Table 2. Preliminary Results of EPA SITE Demonstration - BioTrol* Soil Washing System

ContaminantLevel

Low

High

Parameter

PentachlorophenolTotal Polynuclear Aromatic HydrocarbonsTotal Petroleum HydrocarbonsArsenic

- ChromiumCopper

PentachlorophenolTotal Polynuclear Aromatic HydrocarbonsTotal Petroleum HydrocarbonsArsenicChromiumCopper

Before(mg/kg)

1802403300141715

9802908,800284939

After(mg/kg)

128.62105.09.06.2

86234707.28.55.2

Reduction(percent)

939694645959

919295748387

Washed soil from the SITE demonstration was subjected to the Toxicity CharacteristicLeaching Procedure (TCLP). Results for pentachlorophenol are presented in Table 3. Withboth soil types, the leachate solutions contained less than 1 mg/L pentachlorophenol. Sincethe system is an intensive, water-based scrubbing process, leachability (TCLP) of the washedproduct will usually be very low. This fact should allow washed soil to be placed back on-site without endangering human health or the environment.

Table 3. Results of TCLP Tests - EPA SITE DemonstrationBioTrol* Soil Washing System

SoilContaminantLevel

Low

High

Washed Soil(mg/kg)

1019

5970

Pentachlorophenol

Washed Soil TCLP Leachate(mg/L)

0.230.32

0.740.92

BioTrol. Inc.* 11 Peavey Road • Chaska, Minnesota 55318(61 2) 448-251 5 • I -800-875-2468 • Fax (612) 448-6050

BioTrol® Soil Washing System Page 6

Laboratory Testing Services

Because each site is unique with respect to soil and contaminant characteristics, it isnecessary to conduct preliminary engineering studies (treatability testing) on representativesoil samples. These studies are conducted at BioTrol's Chaska, Minnesota laboratory, andmay include, but are not limited to: j :;

Sample preparation; -i

Sample characterization;

- Chemical analysis- Sieve analysis with chemical analysis of size fractions- Mineralogy ; ,

1 !

-' Leaching studies (to determine partition coefficients);| f

Soil washing tests; ;! . '

Dewatering tests (contaminated fines);

Treatment tests on contaminated process watet and fines (in-house biodegra-dation or carbon treatment tests if applicable, or alternatively, other thirdparty testing).

The preliminary engineering study can. determine:

The ability of soil washing to physically process and effectively treat thecontaminated soil of interest;

The flowsheet required to achieve the desired separations;

Projected operating conditions for full-scale treatment;

Estimated treatment costs for full-scale treatment with an accuracy of -30/+50percent, based on a known volume of soil at a given treatment rate.

Treatment options for the contaminated process water and fines.

On-Site Demonstration Testing

BioTrol is equipped to conduct on-site demonstration testing using a pilot-scale soilwashing system. The purpose of on-site testing is to cbnfinn results obtained in thepreliminary engineering study (treatability test) by using a continuous, pilot-scale systemoperating under actual site conditions. The demonstration can provide assurance to the

i *BioTrof. Inc.* 11 Peavey Road • Chaska. Minnesota 55318(612) 448-251 5 • I -800-875-2468 • Fax (61 2) 448-6050

BioTrol® Soil Washing System Page 7

customer and the appropriate regulatory agencies that the technology can achieve thetreatment levels required. In addition, the pilot-scale tests can determine optimum systemoperating parameters to serve as the basis for more accurate full-scale design specifications.

The pilot system consists of the following components:

Trailer-mounted soil washing system with a nominal treatment capacity of 500to 1,000 pounds per hour;

• Up to 4 process water storage tanks, each with a nominal capacity of 8,000gallons;

Water treatment system (physical or biological);

Mobile office/laboratory.

A demonstration typically lasts 1 to 3 weeks in addition to the time required formobilization and feed preparation. During the demonstration, a generalized test programis employed which focuses on several key operating parameters and their effect on systemperformance. Parameters can include system configuration, soil feed rate, water additionrate, type and addition rate of chemical additives (if required), and dewatering conditions.During steady-state operation, key process streams are sampled at fixed intervals andcomposited prior to chemical analysis. An accurate mass balance for the system can bedetermined by collecting all exiting streams in drums and measuring net drum weights overset time intervals.

Full-Scale Soil Washing Systems

BioTrol engineers can design and construct full-scale soil washing systems for theremediation of a wide variety of soil and contaminant conditions. Based on the results ofa preliminary engineering study or if available, pilot-scale test results, a soil washingflowsheet will be engineered to achieve the necessary separations for a given contaminatedsoil. BioTrol uses a modular design approach to easily accomplish this task while minimizingengineering and construction costs.

The volume of contaminated soil will usually determine the treatment capacity of asystem. For example, remediation of sites in the range of 5,000 to 100,000 cubic yards couldbe accomplished in less than one year with a 20 ton per hour system. For extremely largesites, or for a central facility, permanent or semi-permanent systems could be designed withtreatment capacities in the range of 100 to 200 tons per hour.

Depending upon customer needs, systems can be leased or purchased. BioTrol canprovide technical and supervisory staff, as well as operating and maintenance personnel.Alternatively, technical assistance and training could be provided by BioTrol under terms ofa service contract.

BioTrol. Inc.* I I Peavey Road • Chask'a. Minnesota 55318|612) 448-2515*1 -800-875-2468 • Fax (612! 448-6050

BioTrol® Soil Washing System ; Page 8

A 20 ton per hour mobile system can be assembled on 6 semi-trailers. A typicallayout of this mobile system is shown in Figure 3. Approximately 0.3 to 0.5 acres is requiredfor the complete system, including feed hopper with earthen approach ramp, variousconveyers with associated product piles, process water storage tank(s), water treatmentsystem, and field office. ;

FIELD OFFICEWASHED OVERSIZE ,

HJMOTOR CONTROL CENTERCONTROL ROOM TRAILER

PUG MILL/SCREENTRAILER _____

TREATMENT SKIDSAFEED HOPPER

FROTH FLOTATIONTRAILER

ATTRITION/CYCLONETRAILER

I WASHED SOILCENTERING TRAILER

W>TER T

t100 (9«t

WASHED SOILPILE

CONTAMINATED FINESDEWTERING TRAILER

DEVYkTERED FINES PROCESS VWTERPILE STORAGE TANK

150 l««t

Figure 3. Typical Plan View of a Mobile 20 Ton per Hour Soil Washing System.

Advantages

The BioTrol* Soil Washing System makes use of a patented intensive scrubbingtechnology, unlike other approaches which are based almost entirely upon simple leaching.Use of this intensive scrubbing process is the most effective approach to soil washing.

In addition, BioTrol utilizes a process development approach for each site. This,together with modular construction design, provides the most cost-effective method ofapplying soil washing to a contaminated site. Pre-engineered modules are simply arrangedin the optimal configuration for the unique soil and contaminant conditions, avoidingunnecessary design and construction costs.

BioTrpl's biological treatment technologies can be coupled, where applicable, withsoil washing for treatment of the residual products (process water, contaminated fines, anddebris), minimizing overall remediation costs.

BioTrol, Inc.* I! Peavey Road • Chaska. Minnesota 55318(6! 2) 448-251 5 • I -800-875-2468 • Fax (61 2) 448-6050 .

BioTrol® Soil Washing System Page 9

Costs

Estimated treatment costs for a mobile, commercial-scale, 20 ton per hour soilwashing system are shown graphically in Figure 4 as a function of tons processed. Costsinclude capital recovery (charged as an equipment leasing rate) and water treatment; notincluded are costs for excavation, debris removal, chemical additives, and treatment ordisposal of residuals generated during treatment.

Total cost per ton is the sum of the mobilization and treatment cost components.The estimated treatment cost of roughly $60 per ton varies only slightly with tons processed.Mobilization cost per ton has the most impact at relatively small soil volumes.

COST PER TON, $120

100Total Cost (Treatment *• Mobilization)

80 "

60

20

Treatment Cost

Mobilization Cost

10 20 30 40 50 60TONS PROCESSED (Thousands)

Figure 4. Estimated Treatment Cost (Typical) for a 20 Ton perHour Mobile Soil Washing System.

For illustration, from Figure 4, the estimated soil washing cost for 20,000 tons of soilwould be approximately $71 per ton or $1.42 million. Costs for treatment or disposal of theresiduals generated during soil washing must also be calculated to estimate total remediationcosts. For example, soil washing of 20,000 tons of soil with the characteristics shown inFigure 2 would generate 1,900 tons of woody debris and 1,300 tons of fines, both requiringadditional treatment. Using incineration at $200 per ton for the woody debris and slurry-phase biodegradation for the fines at $100 per ton, treatment of residuals would cost anadditional $510,000 or $25.50 per ton based on 20,000 tons. Total soil treatment costs,including treatment of residuals, is therefore estimated at $96.50 per ton or $1.93 million.

Soil washing unit costs will be significantly lower for systems with larger throughputcapacities or for fixed central facilities. In these cases, total soil washing costs could be inthe range of $25 to $50 per ton.

BioTrol, inc.* I I Peavey Road • Choska. Minne/orc 55.-":i H(6121 448-2515*1 -800-375-2463 • Fax (612i 4- -60:-n

BIOTROL: _... for environmental solutions, naturally!

SOIL WASHING PERFORMANCE DATA

Project Before Aftersite Description____scope ___Contaminant__________(ag/kg)______(ma/kg)______Reference

Wood preserving Pilot Pentachlorophenol 160-1600 5-115 (1)(Minnesota) Total PAH 670 31

S Arsenic 6.5 3.2Chromium 68 41Copper 21 7.2

Wood preserving Treatability Total PAH 4800 230 (1)(California) Arsenic 89 27

Chromium 63 23Copper 29 13Zinc 345 108

Wood preserving Treatability Pentachlorophenol 380 4 (1)(Florida)

Chemical plant Treatability Dichlorobenzidine 770 13 (i)(Michigan) Benzidine 1000 6

Azobenzene 2400 7

Wire drawing Treatability TPH 4700 350 (1)(New Jersey) VOC 2 0.01

Copper 330 100Nickel 110 60Silver 25 4

Town gas Treatability Total PAH 230 11 (1)(Quebec)

Pesticide Treatability Chlordane 55 4.7 (1)formulation Aldrin 47 7.5(Colorado) 4,4-DDT 25 5.0

Dieldrin 46 7.0

Galvanizing Commercial Total Cyanide 250-500 10-15 (2)(Netherlands)

Galvanizing . Commercial Chrome 43-45 11-15 (2)(Netherlands) Nickel 250-89O 40-70

Zinc 460-720 140-200

Fuel Drilling Commercial Kerosine 5000-7000 80-120 (2)(Netherlands)

Galvanizing Commercial Total Cyanide 400-1000 6-10 (2)(Netherlands) Chrome 100-2500 70-120

Cadmium 4-18 0.5-1.4Copper 100-250 25-60Nickel 100-600 50-80Lead 100-450 20-70

Gasworks Commercial Total Cyanide 80-220 5-15 (2)(Netherlands)

Gasworks Commercial Total pCAs 250-400 o.s-io (2)(Netherlands)

Diesel fuel Commercial Mineral Oil 3000-8000 90-120 (2)(Netherlands)

Galvanizing Commercial Total Cyanide 75-300 7-10 (2)(Netherlands) Zinc 160-170 50-80

Unknown Commercial Cyanide 100-250 5-15 (3)(Netherlands) Polynuclear Aromatics 100-150 15-20

Chlorinated 20-30 <1hydrocarbons

Heavy Metals 300 75-125

(over)

BioTrol, Inc. • II Peavey Road • Chaska, Minnesota 55318 • 612/448-

soil washing Performance Data, Continued

Project Before' AfterSite Description_____Scope______Contaminant__________(mo/kg1)______frog/kg)______ReferenceUnknown Commercial Total Organics 5403 j 201 (4)(West Germany) Total Phenol 115 ! 7

Total PAH 728 : , 97.5PCB 3.2 j : 0.5

Unknown Commercial Aromatics 240 i 45 (5)(Netherlands) PNAs 295 ! , 15

Crude Oil 79000 I ; 2300

REFERENCES

1. BioTrol, Inc., Chaska, Minnesota

2. U. S. Environmental Protection Agency, Assessment of Inter-national Technologies for Suiaerfund Applications - Technolo-gy Review and Trip Report Results. EPA/540/2-88/003, Sep-tember 1988, page 18. >

3. U. S. Environmental Protection Agency, Assessment of inter-national Technologies for Suoerfund Applications - Technolo-gy Review and Trip Report Results. EPA/540/?-88/003, Septem-ber 1988, page 26. : :

4. U. S. Environmental Protection Agency, Assessment of Inter-national Technologies for Superfund Applications - Technolp-gy Review and Trip Report Results. EPA/540/2-88/003, Septem-ber 1988, page 43. ;

5. U. S. Environmental Protection Agency, Assessment of Inter-national Technologies for Superfund Applications - Technolo-gy Identification and Selection. EPA/600/2-89/017, May 1989,page 196. , t

BIOTROL*_... .for environmental solutions, naturally!

— FACT SHEET ———————————————

SOIL WASHING - COMMERCIAL SYSTEM

r

Technology Soil washing is a vigorous, water-based, scrubbing processDescription: for excavated soil which uses mineral processing technology.

As an on-site volume reduction process, it generates "clean"washed soil, a contaminated sludge or cake which is primarilythe fraction of soil finer than 38 microns (400 mesh) , andprocess water that may require treatment prior to recycle.This technology can be easily combined with other physical,chemical, biological, or thermal processes for treatment ofthe residual fine soil fraction.

Applicability: Systems can be tailored to remove both organic and inorganiccontaminants. Soils should be predominantly sand and gravel;specifically, the fraction of soil finer than 38 microns (400mesh) should not exceed 20 to 30 percent by weight.

Removal Contaminant levels in the washed soil are generally 90 to 99Efficiency: percent lower than in the feed soil. Removal rates are

dependent upon contaminant, initial contaminant levels, andsoil matrix.

~Pretreatment: Feed soil must be free of debris.

process Rate: Systems can be designed to treat up to 20 tons per hour.

Area Approximately 37,500 square feet will be needed for theRequirement: treatment area (see drawing on reverse side). Process equip-

ment will be skid or trailer mounted with several field-erected process water storage tanks.

Utility Approximately 500 amps of 460 volts, 3 phase power will beRequirement: needed along with a water supply of about 150 gpm during

start-up and a 25 to 75 gpm make-up water supply duringprocess water recycle.

Costs: Capital costs are expected to range from $3 to 5 million.Depending upon the amount of soil to be treated, systems canbe leased or purchased. Operating costs will typically rangefrom $40 to 80 per dry ton, not including capital cost,excavation, debris removal, residuals treatment or disposal,and site restoration.

TTreatability Laboratory testing on representative 15 kg samples canTesting: determine effectiveness of soil washing, pretreatment

requirements, process operating conditions, and estimatedcosts. A mobile 500 Ib/hr pilot unit is available for on-site

' demonstrations to confirm laboratory results in a continuoussystem, providing reassurance of system performance.

IRoad • Chaska, Minnesota 55318 • 612/448-2515 • FAX 6i;