AN INTEGRATED SYSTEM FOR ASSURING SAFE DISPOSAL OF ELECTROPLATING SLUDGE WASTE Tim Cashen, Jesse Conner Chemical Waste Management

Riverdale, IL

I. INTRODUCTION

A. Backeround

As of August 17, 1988 certain listed hazardous wastes are banned from land disposal unless they are first treated. The US Environmental Protection Agency (EPA) is required to define Best Demonstrated Available Technologies (BDAT) for the treatment of the affected wastes. from electroplating operations (EPA waste code "F006") are on the list of wastes affected by the land disposal ban of August 17. EPA has defined stabilization as BDAT for F006 wastes. treatment standards that must be met before a stabilized F006 waste can be land disposed.

Wastewater treatment sludges

The Agency has also defined certain

Stabilization has been used as a treatment technology in the hazardous waste disposal industry for years. The process involves the addition of a cementitious material such as cement kiln dust, lime kiln dust, or Portland cement, or of a pozzolonic material such as fly ash to a liquid waste in order to immobilize the liquid portion of the waste and to reduce the leachability of the hazardous components of the waste. disposal ban prohibited the disposal of bulk liquids in landfills, even if absorbents had been added to the waste in order to reduce the free liquid content. At that time, stabilization was recognized by EPA as an appropriate technology for the reduction of free liquid in a waste, and stabilization agents were recognized as chemical fixation agents rather than as simple absorbents. The treatment standard promulgated by EPA focused on the physical state of the stabilized material. A simple test method, known as the "Paint Filter Test", was promulgated by EPA to determine whether or not free liquids were present in the stabilized wastes. From 1985 until the present, passing the Paint Filter Test was the only treatment standard that a stabilized waste was required to meet.

In May, 1985 an earlier land

Under the land disposal ban in effect since August 17, 1988 , an F006 waste that does not meet treatment standards must be treated in order to immobilize the heavy metal constituents of the waste, whether or not the waste contains any free liquids. The treatment standards that have to be met are defined by metals concentrations in a waste extract developed using a procedure called the "Toxicity Characteristic Leaching Procedure" (TCLP). The TCLP is a time- consuming procedure that must be followed by metals analysis of the extract using expensive and complex laboratory equipment operated by skilled personnel. The impact on disposal site operations has been considerably

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greater than that resulting from the ban on the land disposal of free liquids.

This paper describes procedures under which Chemical Waste Management (CWM) land disposal sites are able to continue acceptance and disposal of F006 wastes in compliance with the requirements of the August 17, 1988 land disposal ban.

B. Regulatory Reauirements

F006 wastes were among the "first third" wastes scheduled for prohibition from land disposal. The Hazardous and Solid Waste Amendments (HSWA), enacted by Congress in November, 1984, required EPA to promulgate regulations to prohibit the land disposal of untreated hazardous wastes. The amendments required EPA to establish treatment technologies and to set treatment standards which "substantially diminish the toxicity of the waste or substantially reduce likelihood of migration of hazardous constituents from the waste so that short-term and long-term threats to human health and the environment are minimized." Wastes that meet treatment standards established by EPA may be land disposed. The amendments required EPA to prepare a schedule by November 8 , 1986 for restricting the land disposal of all hazardous wastes listed as of November 1984. The Congressional statute required that the lists of hazardous waste be prioritized according to volume and toxicity and established three deadlines by which EPA was required to promulgate treatment standards. The first of the three deadlines was August 17, 1988 for wastes of sufficiently high toxicity or volume to be in the first third of the priority list.

On August 17, 1988 EPA issued a final rule in the Federal Register that set treatment standards for F006 waste. EPA identified stabilization as BDAT for the metal constituents of F006 wastes. BDAT for F006 wastes that also contain cyanide is stabilization, preceded by a pretreatment step to destroy the cyanide content. has not yet been identified. for several metals as concentrations in a TCLP extract of treated waste. Total metal concentration is not restricted. Standards have been reserved for cyanide concentration. It is as yet unknown whether cyanide standards will be established for total composition or for a waste extract. Until specific rules on cyanide concentration are issued, established site and corporate standards are assumed to apply.

A specific pretreatment technology for cyanide destruction BDAT treatment standards have been promulgated

Treatment standards are listed below:

BDAT T r e a t m e n t Standards for F006 Waste2

Constituent Maximum for any single grab sample. Total Composition TCLP

(mn/kg) (mdl) Cadmium Not Appl icab le 0.066 Chromium (Total) 5.2 II

"Land Disposal Restrictions for First Third Scheduled Wastes; Final Rule", Federal Register, Vol. 53, No.159, August 17, 1988, p.31137.

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Constituent Maximum for any single grab sample. Total Composition TCLP

(mdkn) - - (ms/l) Lead Not Applicable 0.51 Nickel 0 . 3 2 Silver 0.072 Cyani de Reserved Reserved

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C. Waste Description

Wastes designated "F006" by EPA are defined as "Waste water treatment sludges from electroplating operations except from the following processes: sulfuric acid anodizing of aluminum; ( 2 ) tin plating on carbon steel; ( 3 ) zinc plating (segregated basis) on carbon steel; ( 4 ) aluminum or zinc-aluminum plating on carbon steel; (5) cleaning/stripping associated with tin, zinc, and aluminum plating on carbon steel; and (6) chemical etching and milling of aluminum." F006 wastes are heavy metal contaminated sludges containing up to 60% solids in either the hydroxide or the sulfide form and are classified as non-wastewaters. Chemical Waste Management estimates that there are between one and two million tons of F006 waste generated annually.

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Physical and chemical characteristics of F006 Wastes vary widely depending on their source. Characteristics of F006 waste, as determined by CWM experience, are summarized below with respect to solids content, total metals content, leachable metals content, and pH:

Solids: The physical state of F006 waste varies from a totally liquid state to a material high in solids, containing no free liquids. Approximately 50% of the total F006 wastes received at CWM sites pass the paint filter test (i.e. contain no free liquid) without further treatment. Wastes with very high liquid content may be untreated wastewaters or discarded bath solutions from electroplating operations. Untreated wastewaters are not, in fact, F006 wastes, and some liquids that are designated "F006" by the generator may be misidentified.

Total Metals Content: F006 wastes typically contain significant concentrations of cadmium, chromium, copper, nickel, lead, or zinc. These metals all had BDAT leachability limits defined in the proposed land ban regulation. and zinc were dropped from the list in the final rule. There are no restrictions 02 total metals content. In additior. to the metals listed above, silver also has BDAT limits defined. Silver concentrations appear to be insignificant in F006 wastes typically managed by CWM, and silver leachability does not appear to present a problem.

Copper

Leachable Metals Concentration: Available CWM data indicates that about 8 5 % o f F006 wastes received are hazardous by characteristic of EP toxicity due to leachable cadmium, lead, or chromium. The Extraction Procedure (EP) is a method, predating the TCLP, of generating an aqueous extract of a waste for subsequent analysis of hazardous constituents. It was developed by EPA to determine whether an unlisted waste would be regulated as hazardous due to the leachability of hazardous constituents. For the determination of nonvolatile constituents, the EP toxicity test and the TCLP differ in minor detail. The

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EP toxicity test is still the accepted test method in determining whether a waste is hazardous by characteristic. waste treatment residue is in compliance with BDAT standards for land disposal.

The TCLP is used to determine whether a

Waste DH: The pH of the wastes, as determined by measuring the pH of a 10% slurry of the raw waste in deionized water, are lower than might be expected of metal hydroxide sludges. Only a small fraction of the F006 wastes have a pH greater than 9.0. About half of the wastes have a pH less than 7.0.

D. Management Choices

1. Waste Reduction. F006 wastes generally have a high water concentration. Therefore, dewatering technologies such as vacuum filtration, plate and frame pressure filtration] and centrifugation are appropriate technologies for reducing the overall volume of waste. Dewatered solids are still regulated as F006 waste. Dewatering] by itself, does little to reduce the leachability of metals or of cyanide other than separating the water-soluble components from the dewatered solids. Dewatering, in conjunction with stabilization of the resulting solids, is an appropriate management choice for F006 wastes. Since F006 wastes are generated from wastewaters that have already been treated to reduce volume, further waste reduction is relatively difficult.

2. Metals Recovery. Metals recovery is a management option that may be appropriate for specific F006 waste streams. EPA investigated metals recovery as a possible candidate for BDAT of F006 wastes. The Agency determined that, due to the wide variation in metals concentration and identity] it would be inappropriate to list metal recovery as BDAT for F006 wastes. EPA is still investigating F006 wastes that are now being recovered, in order to determine waste characteristics of subcategories of F006 wastes that are amenable to metal recovery.

CWM has investigated specific metal recovery processes for F006 wastes. Our investigations have concluded that, while some processes are technically feasible, the cost effectiveness of metal recovery may not be attractive. We are continuing to explore recovery options.

3 . Delisting. Listed Hazardous wastes from a specific facility may be "delisted" or excluded from regulation as hazardous wastes if a delisting petition is submitted to EPA and approved by the Administrator. For a delisting petition to be successful:

a. The petitioner must demonstrate that the waste does not meet any of the criteria under which the waste was listed as a hazardous waste.

b. Based on a complete examination, the EPA must determine whether or not factors other than those for which the waste is listed could cause the waste to be a hazardous waste.

In Appendix VI1 of 40 CFR (Code of Federal Regulations, Title 40) part 261, hazardous constituents of F006 waste which are the basis for listing are

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cadmium, hexavalent chromium, nickel, and complexed cyanides. At a minimum, a petitioner would have to demonstrate that those constituents are not present in his waste at concentrations of concern, and to demonstrate that his waste does not meet the definition of a subpart C hazardous waste due to leachability of EP Tox metals. to supply EPA with extensive data on metal and organic component concentrations. continuing basis even if the delisting petition is successful.

In practice, a petitioner would probably have

Testing and record keeping requirements may be imposed on a

A delisting for F006 waste generated by a commercial treatment company was granted by EPA. below for purposes of illustration.

Testing requirements for this company’s F006 waste are listed

Parameter

Arsenic Barium Chromium Cadmium Lead S e 1 enium Silver Mercury Nickel Reactive Cyanide Leachable Cyanide Anthracene 1,2-diphenyl hydrazine Methylene chloride Methyl ethyl ketone N-nitrosodiphenylamine Phenol Tetrachloroethylene Trichloroethylene

Maximum Level

0.315 ppm EPT 6.3 0.315 0.063 I I

0.315 0.063 I t

0.315 0.0126 It

2.205

1.26

0.001 8.18 326 11.9 1566 0.188 0.592 11

I1

11

II

11

11

250 PPm I1

76.8 I I

II

11

It

11

I1

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The above limits for nickel and silver are less restrictive than the BDAT limits set by EPA.

Delisting petitions are generally expensive and time-consuming to prepare, Requirements for future delistings of F006 waste are uncertain in light of inconsistencies between current delisting requirements and land ban regulations. The costs of management of F006 wastes as hazardous wastes must be weighed against the costs of delisting on an individual basis by the generator.

4 . Treatment. Finally, F006 waste may be treated by any appropriate technology to reduce the leachability of the constituent metals to levels below those specified in the table in section B. disposed in landfills authorized to manage F006 wastes.

Treated wastes may be

E. Stabilization as a Treatment Process

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As noted earlier, stabilization has been an accepted waste disposal practice for some time. Chemical Waste Management has studied stabilization processes thoroughly, and has conducted over the years studies in support of this treatment technology.

In 1985, CWM prepared reports in support of CWM procedures to meet the May 8 , 1985 ban on disposal of bulk liquids in landfills, reports were:

Conclusions of these

a. agent,

b. be effectively immobilized by kiln dust,

Cement or lime kiln dust is a widely applicable solidification

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Aqueous wastes containing more than 10% liauid organics may not

c. stabilization process,

Volatile organics may vaporize from the waste during the

d. Kiln dust stabilization of high molecular weight organics at the less than 10% level should be evaluated on a case-by-case basis, and

e. Unconfined compressive strength, as measured by the pocket penetrometer, is effective in monitoring the strength of a solidified product.

f. identified by:

Chemical reactions occurring in stabilization processes can be

1. Temperature change, 2. Hardening over time, 3 . Presence of materials known to react, 4 . Resistance to desorption, and 5. Chemical transformation of toxic compounds.

Additional reports prepared during this time period established procedures for determining mix ratios and established minimum specifications for stabilization reagents. stabilization agent to the weight of waste. several factors, some of which are:

The mix ratio is defined as the ratio the weight of The ideal mix ratio depends on

a. The goal of stabilization (ie. simple solidification or chemical fixation).

b. The nature of the stabilization agent.

c. The amount of free liquid in the waste.

These writings and specifications were established for the disposal of stabilized wastes in secure landfills. At that time, chemical fixation was not a requirement for this disposal scenario. The conversion of liquids into stable solids by processes other than absorption, with certain limitations on

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organics and reactive components, was the goal of stabilization.

F. Stabilization Amlied to F006 Wastes

The advent of the "first-third" landban and its F006 BDAT has made necessary the development of appropriate stabilization techniques and new protocols for QA/QC. These protocols must be established for testing of the raw wastes and end products of stabilization, as well as for reagents. The effects of waste and reagent properties on leachability of the product are much more complex and less well understood than for solidification alone. In addition, leaching test procedures are more difficult, expensive and time consuming.

To meet this new challenge, CWM has investigated leachability of many waste streams, treated and untreated, including F006. The first finding of these investigations, with respect to F006, was that the wastes were not adequately characterized by generators. In 1987, the Company launched an extensive program to define the properties, especially composition and leachability, of F006 waste streams at two of its sites which received major quantities of F006. CWM then conducted a treatability program on selected F006 streams which represented the typical and extreme materials received by its sites. The conclusions of this work were that:

a. Stabilization treatment was capable of meeting current Extraction Procedure Toxicity (EPT) 'characteristic' requirements for F006 wastes under RCRA, and

b. Low levels of leaching can be achieved for copper, nickel and zinc.

This data was submitted to EPA, which subsequently used it in development of the landban BDAT for F006. Data developed during this study is presented in Table I.

It is important to note that CWM's work demonstrated that stabilization using cement kiln dust would meet EPT "characteristic" standards. EPA subsequently set maximum allowable leaching levels under the BDAT which are substantially lower than the "characteristic" standards. In addition, EPA established very low levels for copper, nickel and zinc, metals which had not previously been regulated at all. regulation in the final rule). While these levels were based on CWM's results, they are quite severe when applied to the F006 universe as a whole. F006 wastes, like most others, vary greatly from source to source. And cement -

kiln dust (CKD), the reagent used in CWM study, is equally variable since it is a waste product itself. Therefore, the establishment of'very definitive quality assurance/quality control procedures for both wastes and reagents has become essential. -

(Standards for copper and zinc were subquently dropped from

Unfortunately, the relationships between reagent properties and leachability at the current F006 BDAT levels are not well established, especially for nickel. Because these metals had not been previously regulated (except in California, where the regulatory levels are two to three orders of magnitude

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E-1 bt&liZied Tosal YC. 3 1.30 1270.00 40.20 35.50 435.00 2.30 1560.00 TUP 0.01 0.35 0.15 0.26 0.7l 0.01 0.16

TUP 0.2 0.01 0.51 0.20 0.30 0 .a 0.03 0.03 E-1 S & i l h d

E-2 Iks~ilhd Total 29.1 31.30 755.00 7030.00 409.00 989.00 6.62 4CLB.00 TUP 2.21 0.76 368.00 10.70 22.70 0.14 219.00

TUP 0.2 0.50 0.40 5.40 0.40 1.50 0.03 36.90 TUP 0.5 0.01 0.39 0.25 0.36 0.03 0.05 0.01

E-2 S l d d l k d

E-2 Ikst&ilhd Total 67.6 67.30 7l6.00 693.00 25.70 259.00 39.00 631.00 TUP 1.13 0.43 1.33 0.26 1.10 0.02 5.41

TUP 0.2 0.06 0.m 1.64 0.3 0.23 0.20 0.05 TUP 0.5 0.02 0.20 1.85 0.41 0.15 0.05 0.03

E-2 S a m

E-l3 Wilid

TUP

TUP TUP

Total 89.1

E-13 Stabilized 1.69 12.93 18.60 ll.40 %.00 6.26 8.86 0.66 7.58 4.12 6.86 158.00 1.64 2.28

1.0 4.01 0.40 0.23 0.20 4.35 0.09 0.05 1.5 0.01 0.35 0.19 0.36 2.47 0.15 0.03

E-17 LkkbliZed Total 91.2 0.97 2.00 1.40 16.00 3700.00 0.51 16.00 TUP 0.70 0.30 0.40 10.10 3950.00 0.60 10.80

E-17 Stab- TUP 1.0 4.01 0.m 0.15 0.21 0.02 0.03 0.01

E-25 Wilized Total 68.2 1.30 llo.OO 1510.00 88.50 37.00 9 . 0 5 m . 0 0 TUP 0.22 0.18 4.60 0.45 0.52 0.16 x)30.00

TUP 0.2 0.01 0.23 0.30 0.30 0.10 0.03 32.00 TUP 0.5 0.01 0.30 0.27 0.34 0.02 0.03 0.01

E-25 Stabilized

E49 Wilid Total 61.6 5 . a 644.0027400.0024500.00 5730.00 19.10 322.00 TUP 0.01 0.01 l6.90 50.20 16.10 4.01 1.29

TUP 0.20 4.01 0.03 3.N 2.39 1.09 4.01 0.87 E49 Stab-

TUP 0.50 4.01 0.2l 0.46 0.27 0.02 4.01 4.01

%le I.

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I

Total TUP TUP

A-2 SiAXLhd

m

Total A-3 bt&i.l.kd

m A-3 S & M

80.6 720.0012xx).00 160.00 52.00 701.00 5.2835900.00 23.60 25.30 1.14 0.45 9.78 0.a 867.00

0.2 3.23 0.25 0.20 0.24 0.53 0.a 3.40 0.5 0.01 0.30 0.29 0 . 3 0.W 0.05 0.W

81.0 7.28 3100.00 1220.00 ll3.0319503.00 4.0827800.00 0.30 38.X) 31.70 3.37 730.00 0.12 l2CD.00

0.2 0.02 0.21 0.21 0.30 16.50 0.03 36.30 0.5 0.01 0.38 0.20 0.36 0.05 0.05 0.a

A-5 UnStabili.nd Total m 69.3 5.3942m.0310600.00 l56.0313ooo.00 12.50 m.OO

0.06 360.03 8.69 1.03 152.00 0.05 0.62 0.2 0.01 3.03 0.40 0.30 0.40 0.03 0.02 0.5 0.01 1.2l 0.42 0.38 0.10 0.05 0.02

A-I5 L M A M Total 79.5 5.81 47.9 1760.00 169.03 23700.00 8.ll 15703.00 m 0.18 0.a 483.00 4.22 644.03 0.31 63.00 m 0.2 0.01 0.10 0.50 0.31 15.70 0.03 4.54 m 0.5 0.01 0.20 0.32 0.37 0.03 0.05 0.02

A-I5 stcbilized

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higher than the EPA final rule), little data is available. CWM is presently studying these relationships so that reagent testing can be used to accurately predict leachability of the stabilized product, as was done for the liquid-in- landfills ban. Until generalized prediction methods are available, treaters must demonstrate treatment effectiveness on a case-by case basis.

In addition to the reagents, it is now necessary to establish more stringent controls on the properties of the wastes themselves. The RCRA definition of F006 clearly states that the waste is sludge from wastewater treatment. normally would preclude the presence of large quantities of hexavalent chromium, reactive (soluble) cyanide or sulfides, or soluble-complexed metals. Such highly soluble species, if present, are usually associated with the aqueous phase in water treatment, not the sludge. For this reason, they are usually destroyed at the source so that water effluent discharge limits can be achieved. received at CWM sites as F006. Except for site limits on reactive cyanide and sulfide, this was not a problem in the past. however, levels’ of hexavalent chromium and soluble, complexed metals higher than about 50 times the BDAT levels may result in the stabilized product failing the BDAT requirements. Wastes containing high levels of these species will require pretreatment, either by the generator or by CWM. EPA has not yet set a maximum leaching level for cyanide, but this will also be a matter of concern at CWM sites. Until EPA publishes cyanide limits, site and corporate cyanide disposal policies are presumed to apply.

This

However, they are frequently found at high levels in wastes

Under the proposed BDAT,

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11. Overview of Waste Acceptance and Stabilization Process

General procedures for acceptance and treatment of an F006 waste at a CWM site are

1.

2 .

3 .

4 .

5 .

6 .

7 .

outlined below.

The generator submits a representative sample ("sales" sample) of his waste, a completed and signed Waste Material Profile Sheet, and a Certification of Representative Sample form to the landfill facility for review and analysis. If the generator believes that his waste meets the requirements of the BDAT limits without further treatment, he must sign n certification statement to that effect and provide confirming data. This certification would be necessary if:

a. The generator produces an F006 waste which meets the BDAT requirements without any treatment, or

b . The generator treats his own waste to BDAT specifications, or

c. The generator is a treater of hazardous wastes who receives wastes from other generators for treatment before shipment to a CWM disposal facility.

CWM site laboratory personnel review sample documentation and perform "fingerprint" tests of the waste sample. Stabilization testing on a lab scale is performed. laboratory manager considers them appropriate, or if required by the site Waste Analysis Plan.

More extensive analyses may be conducted if the

When the waste is accepted as a treatable material, site laboratory personnel notify the appropriate CWM sales office. begin transportation of the waste to the landfill site after scheduling the shipment with site personnel or with CWM sales and after completing a Land Ban Notification Form, which must accompany each shipment.

The generator may

Upon receipt of the waste at the gate, the material will be sampled and evaluated by "fingerprint" analyses to ensure that the chemical and physical characteristics of the incoming waste are comparable to the sales sample. Stabilization testing is performed on wastes that have not been previously tested as a sales sample. Wastes which do not conform are subject to refusal or increased disposal costs.

Waste will be stored in a containment area, along with other F006 wastes, until the material can be processed.

From the containment area the waste will be directed to the stabilization process area, where the waste will be mixed with stabilization reagent at ratios consistent with laboratory stabilization test results. The method of mixing is site dependent.

After mixing, the material will be transferred to a holding area where it will remain until any required production testing is completed.

8. Production testing will be conducted according to a schedule determined by the site permit or operating plan. required, an operator will collect samples of the treated material. Samples will be taken every hour for a continuous process and from every batch for a batch mixing process. These samples will then be composited into one daily production sample, which will be tested by TCLP protocols.

When production testing is

9 . If the TCLP results are within BDAT limits, the material will be transferred to the landfill cell. If test results are outside BDAT limits, stabilization processing will cease until problems are identified and remedied. The off-spec product will be resampled and retested. results are still found to be outside BDAT limits, the product will be returned to the process area for additional treatment. Otherwise, the material will be landfilled.

If

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111. REQUIREMENTS OF RESPONSIBLE PARTIES

Responsibilities of generators, treaters,and disposers of F006 wastes are outlined below. Generally, a CWM land disposal facility will be both the treater and the disposer of a waste. In some cases, however, a generator may elect to treat his own waste, or a CWM or non-CWM company may treat F006 waste before transportation to a CWM disposal facility.

A . Generator Reuuirements

Basic requirements of generators who use CWM disposal facilities are summarized below :

1. The generator must obtain a representative sample of the waste and complete a "Generator's Certification of Representative Sample" form. (Form CWM-51).

2 . The generator must complete and sign a copy of the "Generator's Waste Material Profile Sheet." (Form CWM-6000).

3 . The Waste Profile Sheet, Certification of Representative Sample, and the sample must be forwarded to the appropriate CWM facility for review and approval.

A CWM sales representative will assist the generator through these required procedures in addition to obtaining necessary transportation and disposal agreements. In addition to these basic requirements for all wastes going to a CWM facility, the generator of an F006 waste must:

1. Ensure that his waste is, in fact, an F006 waste.

2. Take steps to segregate his F006 waste from other wastes and from miscellaneous debris (gloves, boots, protective clothing, empty cans, etc.) that tends to accumulate in waste containers.

3 . Ensure that his waste does not contain hexavalent chromium or complexed nickel in any appreciable quantities. (Screening limits are 15 ppm Ni and 100 ppm Cr+6. Screening limits are crude indicators only. The TCLP test is the final determinant of acceptable metals limits.) Chromium and nickel in these forms are highly soluble, and their mobility is not sufficiently reduced by the stabilization process.

4 . Take steps to ensure that his waste does not contain cyanide or sulfide in amounts sufficient to classify the waste as a reactive waste according to individual site criteria.

5. Complete a First Third Land Ban Notification Form for each load shipped to a CWM facility.

B. Requirements of the Treater of an F006 waste.

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The treater of an F006 waste must ensure that the treated product meets the BDAT standards outlined in section I-B. In order for a treater of F006 waste -

to maintain quality control of the treated product, the quality of stabilization reagents used, as well as the characteristics of incoming waste must be controlled. In most cases, the treater of an F006 waste will be the same CWM company that disposes of the waste. This section will outline general guidelines for the quality control of incoming waste, stabilization reagents, and treated product when the treater is a CWM company. Wastes received from non-CWM treaters are subject to the requirements of the following section (Requirements of the Disposer of an F006 Waste). F006 waste that meets BDAT standards without treatment will be considered a treated waste subject to these same requirements.

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Untreated

1. Oualitv Control of Incoming Waste

Incoming wastes are examined in at least two instances:

a. As a sales sample, which is supplied by the generator before the waste is accepted for disposal, and

b. As an incoming waste sample, which is obtained by CWM site personnel from each waste shipment.

Below are listed criteria considered necessary (but perhaps not sufficient) for successful stabilization of F006 waste.

- Hexavalent chromium < 100 mg/kg

- Soluble, complexed nickel < 15 mg/kg

- Soluble/reactive cyanide and sulfide

- Physical state

< Site limits

Sludge (not a low-viscosity or solids-free liquid)

- PH > 4.0

Most of these parameters can be determined by standard site fingerprint tests both on sales samples and incoming load samples. Incoming waste loads, which are found to differ significantly from the sales sample based on fingerprint tests, may be held for more exhaustive tests.

A treatability test, followed by a leach test of the treated sample, is run on every sales sample of F006 waste. This can be run using a single standard mix ratio, which has been found to be successful for other wastes, using the stabilization reagent available to the site.

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2. Quality Control of Stabilization Reagents

In view of the F006 landban BDAT requirements, protocols must be established for testing of the reagents used to stabilize wastes as well as for the raw wastes and the end products of stabilization. The effects of reagent properties on leachability of the product are much more complex and less understood than for solidification alone. The final test, in any case, is leachability of the solid end product.

We cannot yet specify the exact reagent properties and characteristics which will assure that a stabilized F006 waste will meet the new leaching standards in every instance. which are necessary, if not sufficient, to ensure that a stabilized waste will meet BDAT standards.

Summarized below are some of the reagent specifications

REAGENT PROPERTIES

- Must be a free flowing powder

- No lumps larger than 3/8 inch

- No significant contamination by foreign material

- Moisture (105OC) c 1%

- Loss on ignition ( l l O O o ~ ) < 30%

- Alkalinity as CaO > 15% (not applicable for Portland cement)

- Solidification ratio < 3 Minimum ratio of reagent to distilled water required to produce a solid with no free water and minimum bearing strength of 1.0 tons/ft2 after 24 hours

Since stabilization reagents are subject to significant performance variations due to process changes and storage conditions, treaters must establish procedures to ensure consistent quality.

A lab treatability test can be used as a comparative test for new reagents. For the evaluation of new stabilization reagents, a sample of waste, which has been successfully treated using another stabilization reagent, must be available, A single, previously successful, mix ratio may be used for comparative purposes. predict the performance of a new stabilization reagent, test using a waste with known properties, may be the most important factor in the evaluation of a new reagent.

In light of the lack of objective criteria necessary to a lab treatability

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3 . Quality Control of Stabilized Product

Stabilized product will periodically be sampled and tested to ensure that metals leachability is within BDAT standards.

S amp 1 inq Sampling and analysis of treated product is conducted at intervals as specified in the site's Waste Analysis Plan. When testing is due, a composite sample of a "production unit" will be drawn and tested for leachable metals. A "production unit" is defined as the total production of an eight-hour shift. The sampling protocol will depend on the type of stabilization operation. For batch methods of stabilization a grab sample will be drawn from each batch. For continuous processes a grab sample will be drawn each hour. Each grab sample must be of equal volume (from one pint to one quart). All grab samples from a production shift will be combined and mixed together well. A subsample of this composite will be retained for TCLP testing. Stabilized material from the shift production needs to be segregated and held in a designated area until results from the TCLP testing are available.

Leachability of Metals

A one-hundred gram sample of the composite sample is extracted according to the procedure in 40CFR, part 268, Appendix I (Toxicity Characteristic Leaching Procedure). Following extraction, the waste extract is prepared for analysis of BDAT metals.

C. Requirements of the Disposer of an F006 Waste.

If the waste was treated by the same facility that will dispose of the waste, the procedures outlined above in section B will apply. treated off site, the following modifications apply:

If the waste was

1. The generator of the waste or the treater who stabilized the waste must certify in writing that the waste, as received by CWM, is within the specifications of the BDAT limits for F006 waste by completing a Land Ban Notification Form to accompany each load.

2 . The generator or treater must supply analytical data demonstrating that the waste is within BDAT limits for land disposal of F006 waste .

3 . The generator or treater must recertify that his stabilized waste is within specification yearly. accompanied by a new waste sample.

The recertification must be

4. The disposal facility must keep all land ban records (testing, notification/certification forms) for five years.

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IV . CONCLUSION

August 17, 1988 USA EPA rules regulating land disposal of F006 wastes require extensive quality control treatment and disposal practices to insure wastes are adequately treated. Chemical Waste Management has developed the necessary system described here. Our system is based on a long history of stabilization and waste characterization research as summarized in the many Chemical Waste Management reports supporting both this document and the proposed standards. Following these procedures insures adequate treatment in the disposal of F006 wastes under EPA proposed rules.

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