Land Disposal Restrictions: Proposed Treatability Variance For Citgo Petroleum

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 268

[FRL-5060-8]

Land Disposal Restrictions: Proposed Treatability Variance For

Citgo Petroleum

AGENCY: Environmental Protection Agency (EPA).

ACTION:Proposed approval of site-specific treatability variance for

Citgo Petroleum Facility at Lake Charles, Louisiana.

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SUMMARY: The United States Environmental Protection Agency (EPA or

Agency) is today proposing to grant a site-specific treatability

variance from the Land Disposal Restriction (LDR) treatment standards

for F037 and F038 nonwastewaters that are contained in, and to be

removed from, a 26 acre surface impoundment (Surge Pond). The specific

waste was generated when the Surge Pond filled with water and primary

sludge from the disposal of process wastewater and stormwater at the

Citgo Corporation petroleum refinery located outside Lake Charles,

Louisiana. Approximately 625,000 tons of waste remains in and is to be

removed from the surface impoundment; this waste was subject to a

national capacity variance until June 30, 1994.

If this proposal is finalized, Citgo may complete their remediation

effort that was approved by the Louisiana Department of Environmental

Quality (LDEQ) and EPA Region VI, provided they comply with the

alternative treatment standards specified in this proposal, and also

comply with any other applicable land disposal restrictions for this

waste as specified in 40 CFR Part 268.

DATES: EPA is requesting comments regarding today's proposed decision.

Comments will be accepted until September 29, 1994. Comments postmarked

after the close of the comment period will be stamped ``late''.

ADDRESSES: Send three copies of your comments to EPA. Two copies should

be sent to the EPA RCRA Docket (5305), U.S. Environmental Protection

Agency, 401 M Street, SW., Washington, DC 20460. A third copy should be

sent to Richard Kinch, Chief, Waste Treatment Branch (5302W), U.S.

Environmental Protection Agency, 401 M Street, SW., Washington, DC

20460. Identify your comments at the top with the regulatory docket

number: F-94-TVLP-FFFFF.

The official record for this rulemaking is identified by Docket

Number F-94-TVLP-FFFFF, and is located in the EPA RCRA Docket, U.S.

Environmental Protection Agency, room 2616, 401 M Street, SW.,

Washington, DC 20460. The RCRA Docket is open from 9 a.m. to 4 p.m.

Monday through Friday, except for Federal holidays. The public must

make an appointment to review docket materials by calling (202) 260-

9327. The public may copy a maximum of 100 pages from any regulatory

document at no cost. Additional copies cost $.15 per page. The mailing

address is EPA RCRA Docket (5305), U.S. Environmental Protection

Agency, 401 M Street, SW., Washington, DC 20460.

FOR FURTHER INFORMATION CONTACT: For general information contact the

RCRA Hotline at (800) 424-9346 toll-free or (703) 920-9810 locally. For

information on specific aspects of this document, contact Shaun

McGarvey, Treatment Technology Section, Waste Treatment Branch (5302W),

Office of Solid Waste, U.S. Environmental Protection Agency, 401 M

Street SW., Washington, DC 20460, (703) 308-8603.

Supplementary Information:

Table of Contents

I. Background

A. Authority

B. Site Description

C. Regulatory History

1. Surface Impoundment Regulations

2. Listing and LDR Treatment Standards for F037 and F038

3. Citgo's Management Decisions

D. Waste Description

E. Description of Treatment System

F. Summary of Citgo's Petition for a Treatability Variance

II. Basis for Proposed Treatability Variance

A. EPA Evaluation of Citgo's Petition

B. Proposed Alternative Treatment Standards

I. Background

A. Authority

Under section 3004(m) of the Hazardous and Solid Waste Amendments

of 1984 (HSWA), EPA is required to set ``levels or methods of

treatment, if any, which substantially diminish the toxicity of the

waste or substantially reduce the 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.'' EPA has interpreted

this language to mean treatment standards based on the performance of

best demonstrated available technology (BDAT). This interpretation was

sustained by the D.C. Circuit in HWTC v. EPA, 886 F.2d 355 (D.C. Cir.

1989), cert. den. 111 S. Ct. 139 (1990). The Agency, however, has

recognized that there may be wastes that cannot be treated to the

levels specified in the rules, due to the fact that the wastes are in a

form that is substantially more difficult to treat than those the

Agency evaluated in establishing the treatment standard (51 FR 40576,

November 7, 1986), or where the treatment technology is inappropriate

for the waste. For such wastes, EPA has established a treatability

variance (40 CFR 268.44), to establish alternative treatment standards

on a case-by-case basis.

The requirements for qualifying for a site-specific treatability

variance are contained in 40 CFR 268.44(h), which states, ``Where the

treatment standard is expressed as a concentration in a waste or waste

extract and a waste generated under conditions specific to only one

site cannot be treated to the specified level or where the treatment

technology is not appropriate to the waste, the generator or treatment

facility may apply to the Administrator, or her designated

representative, for a site-specific variance from the treatment

standard. The applicant for a site-specific variance must demonstrate

that because the physical or chemical properties of the waste differ

significantly from the waste analyzed in developing the treatment

standard, the waste cannot be treated to specified levels or by the

specified methods.'' For a more thorough discussion of the conditions

which justify granting a treatability variance and the supporting

information the petitioner is required to submit, please refer to the

November 7, 1986 Federal Register Notice, also known as the Solvents

and Dioxins Final LDR Rule (51 FR 40605-40606).

B. Site Description

The specific site addressed by this proposed variance is located at

Citgo Corporation's Lake Charles Refinery, 4401 Louisiana Highway 108

in Calcasieu County in the southwest corner of Louisiana. The surface

impoundment in question, referred to as the ``Surge Pond'' in Citgo's

literature, is situated immediately adjacent to the west bank of the

Calcasieu River, approximately 10 miles southwest of Lake Charles and

15 miles north of the Sabine National Wildlife Refuge. The Surge Pond

has a surface area of twenty six (26) acres. Much of the pond is 15 to

20 feet deep; the deepest part is about 40 feet deep. The water surface

elevation of the pond is six feet above sea level; the water layer is

about 15 feet deep. The bottom of the pond is filled with sludge which

has been accumulating since the 1940's. The pond has been receiving

untreated petroleum refining process water and stormwater runoff from

the site throughout most of the site's history. The sludge at the

bottom of the pond is a primary sludge generated by the settling of

petroleum refining wastewater and thus meets the definition of RCRA

Hazardous Waste Codes F037 and F038.

The Surge Pond discharges into the old onsite wastewater treatment

system. This system consists of an earthen equalization basin, followed

by dissolved air flotation (DAF) tanks, an earthen aeration basin,

clarifier tanks, a settling pond, a polishing pond, and then discharges

into the Calcasieu river at a NPDES regulated outfall (Permit number

LA0005941). (The company's request for a treatability variance only

includes sludge from the Surge Pond; it does not include any sludge

generated by the rest of the old wastewater treatment system.)

A new onsite wastewater treatment system has been in operation

since May 13, 1994. The system now receives stormwater and process

wastewater from the site. The system consists primarily of above ground

tanks with floating roofs. Air emissions from the tanks are routed to a

vapor control system. The new wastewater flow path is from API

separators, to an equalization tank, to a DAF unit, to aerated

activated sludge tanks, to a clarifier. Clarifier effluent discharges

to the settling pond of the old wastewater treatment system.

C. Regulatory History

1. Regulations Applying to Citgo's Surge Pond

The Surge Pond began operating in the late 1940's, and has been

generating sludge since that time. The RCRA regulatory history of the

impoundment, set out in full in Citgo's petition, is complicated. (See

Citgo's variance petition for a more thorough discussion of the

regulatory history of Citgo's refinery.)

Most of this history is not relevant for evaluating the petition.

It is clear, however, that the sludge in the pond is listed as F037 and

F038; as such, it became subject to the land disposal restriction

treatment requirements and prohibitions on June 30, 1994, the date that

the national capacity variance for this waste expired. See Sec. 268.36

(c), promulgated at 57 FR 37271 (Aug. 18, 1992). Thus, the sludge or

any residues generated from its treatment cannot be placed on the land,

including back in the Surge Pond, unless first treated to meet the

treatment standards for F037/F038, since the impoundment does not

qualify as a section 3005 (j) (11) impoundment. Nor does the company

want to put the treated sludge back into the impoundment. The company

has also constructed a new tank-based wastewater treatment system to

replace the old system of surface impoundments.

2. Listing and LDR Treatment Standards for F037 and F038

As indicated earlier, sludge from the Surge Pond meets the

definition of F037 and F038 nonwastewaters. The listing of these waste

codes was promulgated on November 2, 1990 (55 FR 46354) and amended on

May 13, 1991 (56 FR 21955). LDR treatment standards for these wastes

were finalized on August 18, 1992 (Phase I LDR Rule).

The final treatment standards for nonwastewaters set total

concentration limits for 14 hazardous organic constituents based on the

performance of combustion or solvent extraction, TCLP leachate

concentration limits for nickel and chromium based on stabilization,

and a total cyanide standard based on combustion. However, a two-year

national capacity variance was granted for F037/F038 wastes generated

from the cleanout of surface impoundments, on the basis of a

determination that existing capacity at bulk solid incineration systems

was insufficient to treat these wastes. This capacity variance expired

on June 30, 1994. Before this date, these wastes could be land disposed

in a subtitle C facility without meeting the LDR treatment standards.

EPA also determined that impoundments receiving F037/F038 wastes

during the national capacity variance would continue to have four years

from the promulgation of the F037/F038 listing date to retrofit the

impoundments to meet the minimum technology requirements (MTRs), or to

close them (59 FR 37220-37221). After June 30, 1994, the wastes must

meet either the LDR treatment standards or alternative standards

established by a treatability variance prior to land disposal, be

granted a case-by-case capacity extension, or be disposed of in a unit

from which there is no migration.

3. Citgo's Management Decisions

Citgo conducted a feasibility study in early 1993 (after

promulgation of the LDRs for F037/F038) to compare and evaluate their

options for closing the Surge Pond. The closure alternatives considered

were a ``no action'' alternative, traditional RCRA clean closure,

traditional RCRA in-situ closure as a landfill, closure by removal

followed by risk assessment (risk based closure), and delay of closure.

Citgo chose to pursue closure by removal followed by risk assessment

(see Citgo's variance petition for the basis of their decision). This

alternative entailed treatment and disposal of a tremendous quantity of

F037/F038 nonwastewater that was to be removed from the pond. The

treatment technologies considered in this feasibility study included:

In-situ and ex-situ stabilization

In-situ and ex-situ bioremediation

In-situ steam stripping

Ex-situ thermal desorption

Ex-situ incineration

In-situ and ex-situ air sparging

Ex-situ dewatering

Ex-situ oil/water separation

At the time this feasibility study was conducted (early 1993),

approximately a year and a half remained before the expiration of the

national capacity variance for the F037/F038 wastes. Citgo planned that

the cleanout would be finished and that all the sludge removed would be

landfilled in a subtitle C unit meeting the minimum technology

requirements, as required by Sec. 268.5(h)(2), before the national

capacity variance expired. They constructed a treatment system which is

designed to meet the NESHAP waste limit for benzene and controls air

emissions. The treated waste also must meet certain landfill acceptance

criteria. In particular, this treatment system meets the LDR level for

benzene and also achieves oil recovery, partial removal of volatile

organics, and dewatering and stabilization of the sludge which meets

LDR standards for nickel and chromium (the two regulated metals in

F037/F038 wastes); however, the treatment system would not meet the LDR

treatment standards for most of the semivolatile organics. Wastewater

from the system is redisposed back into the Surge Pond.

Citgo hired a contractor to perform the removal and treatment of

the Surge Pond sludge. The conditions of the contract stated that the

clean-up must be completed before June 30, 1994. However, due to

technical difficulties with scale-up, dewatering performance, and the

automatic control system for the vapor recovery system, the progress of

the clean-up was seriously delayed. In early 1994, it became clear to

Citgo that the clean-up would not be finished before the expiration of

the national capacity variance and that they would need a treatability

variance from the LDRs in order to continue disposing of the residuals

from their existing sludge treatment system.

D. Waste Description

One of the most significant distinguishing characteristics of this

waste is its tremendous quantity. The feasibility study conducted in

early 1993 estimated that the total volume of sludge contained in the

Surge Pond was 770,000 cubic yards, and the total mass as 745,000 tons

with a 30% solids content (230,000 tons dry solids). However, Citgo

indicated in its petition that it now appears that these quantities

were underestimated by as much as 25%, which would mean that the

original mass of sludge was about 993,000 tons. Citgo indicated that

approximately 625,000 tons of sludge would remain in the pond after

June 30, 1994, the date that the national capacity variance for this

waste expired. This is the quantity of waste that will be affected by

this proposed variance. Approximately 427,000 tons of solid residual

will be generated by the treatment of the waste in the Surge Pond.

Sampling and analysis of the sludge was performed for Citgo's

feasibility study and again for this variance petition. Concentrations

of hazardous constituents in untreated sludge are summarized in table

A.

E. Description of On-site Treatment System

The treatment system Citgo is using consists of air sparging in

tanks to remove benzene (other volatiles do not appear to be removed

effectively) followed by sludge dewatering. Air emissions from some of

the unit processes (shaker system, air sparging tanks, and chemical mix

tanks) are routed to a vapor control system which consists of scrubbers

for removal of hydrogen sulfide and a portable thermal oxidizer for

destruction of volatile organics. The dewatered sludge is then mixed

with lime or flyash for purposes of stabilization of metals and

providing structural integrity to meet the landfill acceptance

criteria. The stabilized sludge is land disposed at Chemical Waste

Management's Subtitle C landfill in Carlyss, Louisiana. The liquid

phase goes to tanks functioning as oil-water separators for recovery of

oil; approximately 18% of the oil present in the sludge is recovered.

The aqueous discharge (wastewater) from the separators is discharged

back into the Surge Pond; overflow from the Surge Pond discharges into

the old wastewater treatment system.

Regulations that the sludge treatment system must satisfy include

the NPDES permit limits for discharge of all site wastewaters, air

emission limits, the benzene NESHAP limit (10 ppm), and structural

criteria for acceptance at the landfill. Treatment performance data is

presented in table B.

F. Summary of Citgo's Petition for a Treatability Variance

Citgo submitted a site-specific treatability variance petition to

EPA on April 13, 1994, and submitted additional materials as per EPA's

request. The petition requests that EPA allow Citgo to continue land

disposing the treated sludge generated by the remediation of the Surge

Pond and to meet alternate LDR standards for their F037/F038

nonwastewaters. The alternative treatment standards suggested by Citgo

are presented in table B.

Citgo made the following arguments as justification for this

request:

(1) Citgo claimed that incineration is not an appropriate

(technology for this waste because

(a) the tremendous quantity of wastes generated by this remediation

exceeds the annual excess capacity available nationwide for F037/F038

wastes (Citgo estimated that the eight incinerators willing to treat

their F037/F038 waste can treat 374 thousand tons of F037/F038 wastes

per year; the Surge Pond remediation will generate approximately 427

thousand tons of waste after June 30),

(b) the metal content of this waste (4,084 ppm reported average) is

higher than that of typical F037/F038 wastes, such that incineration of

this waste could release large quantities of metals to the atmosphere,

and

(c) the hazards of transporting the waste long distances for

offsite incineration exceed the hazards of treating the waste onsite

and disposing the residuals in the subtitle C landfill seven miles from

the site. Citgo estimated that transportation of 427 thousand tons of

waste to offsite incinerators would require a total of 24 million

highway miles and result in 48 traffic accidents (24 with a possible

release of hazardous material to the environment) and 7 traffic

fatalities.

(2) Citgo claimed that cement kiln combustion is inappropriate for

this waste due to the low BTU content (less than 2,000 BTU/lb) of the

waste.

(3) Citgo claimed that, ``When compared with other treatment

options, the CITGO approach is clearly the safest for the environment

and human health.''

(4) The company could simply close the impoundment with the waste

in place, thus doing no treatment at all.

II. Basis for Proposed Treatability Variance

A. EPA Evaluation of Citgo's Petition

After careful evaluation, EPA is proposing to grant a treatability

variance for the F037 and F038 nonwastewaters generated by the

remediation of the Surge Pond, subject to the conditions described in

section II.B. Our basis for proposing to grant the petition is

described below:

(1) EPA wants the remediation of the Surge Pond to be completed.

Although Citgo has stated that they prefer to close the Surge Pond by

removal of the sludge followed by a risk assessment, the closure

regulations for interim status surface impoundments in Sec. 265.228 (52

FR 8708, March 19, 1987, amended at 57 FR 3493, Jan. 29, 1992) allow

the option of closing the impoundment with the waste in place. This

would mean that several hundred thousands tons of untreated hazardous

waste could remain indefinitely in an unlined impoundment immediately

adjacent to and in hydraulic communication with the Calcasieu River,

several miles upstream from the Sabine National Wildlife Refuge.

Hazardous waste constituents have already been detected in the

groundwater collected and analyzed from monitoring wells in the

vicinity of the Surge Pond. EPA, the authorized state, and the company

have worked out an arrangement whereby the impoundment can be

effectively closed and remediated, and the sludge securely disposed

after treatment. Thus, the alternative of closing in place appears to

be clearly less desirable than partial though substantial treatment of

the sludge followed by disposal of the treatment residue in a subtitle

C MTR landfill. EPA supports the ongoing remediation plan, Citgo's

choice to close the pond by removal of hazardous waste, rather than

closing with the waste in place.

(2) As noted, Citgo's remediation plan has been approved by

Louisiana Department of Environmental Quality (LDEQ). LDEQ has also

approved a temporary variance to a small source exemption for air

emissions which establishes operating specifications for temperature

and residence time for the portable thermal oxidizer used to destroy

stripped volatile organics. Although regional approval of the

remediation plan was not required, EPA Region VI concurs with this

proposed treatability variance and is currently reviewing Citgo's plan

for risk based closure of the Surge Pond.

(3) EPA agrees that standards which could necessitate offsite

incineration are not appropriate for this waste, within the meaning of

Sec. 268.44(a). The quantity of waste being generated by this

remediation exceeds the available incineration capacity for F037/F038

wastes. Although the national capacity variance for this waste has just

expired, the fact remains that offsite incineration is not logistically

feasible for this large quantity of waste.

(4) The Citgo treatment system achieves oil recovery and

substantial treatment of some of the regulated constituents. Citgo

estimates that approximately 16 thousand tons of oil will be recovered

during the course of this remediation. Waste minimization is a high

priority for the Agency and activities achieving recovery of valuable

resources are strongly encouraged. In addition, the Citgo treatment

system achieves substantial reduction of most of the regulated

constituents.

In short, EPA is proposing to grant the variance request because

the treatment technology that is the basis for BDAT ``is not

appropriate to the waste'' under Sec. 268.44 (a) and (h). The treatment

technology is not appropriate because of the enormous volume of sludge

needed to be treated and because requiring those standards to be met

could result in a net environmental detriment. (EPA is convinced that

CITGO, for reasons that are legally permissible, will choose to close

its impoundment with hundreds of thousands of tons of sludge left in

place.) Under these exceptional circumstances, EPA believes that a

treatability variance can be issued and accordingly is proposing to do

so here.

Although EPA is proposing to grant Citgo a treatability variance

for the F037/F038 wastes contained in and to be removed from the Surge

Pond, the company made a statement in their petition with which the

Agency does not agree. In particular, the Agency does not agree that

the chemical properties of the waste make thermal destuction

inappropriate for this waste. Specifically, EPA does not agree that the

metal content of the waste is sufficiently high to make the waste

nonamenable to combustion.

Finally, it should be noted that wastewater from the sludge

treatment system is currently being put back in the Surge Pond.

Although characterization of this wastewater has not been provided,

this wastewater may contain significant concentrations of volatile

organics which could simply evaporate from the pond. It may be possible

to reduce releases of volatile organics from the wastewater to the air

by treating this wastewater in the newly constructed closed-tank

wastewater treatment system instead of the old system of open surface

impoundments. However, the Final Listing Rule for F037/F038 established

the Agency's position that wastewater removed from wastewater treatment

sludges by dewatering that is recycled to process operation or returned

to the treatment system is not a ``derived from'' hazardous wastes if

it can be demonstrated that the water removed from the sludge is no

more contaminated than the original influent to the treatment unit from

which the sludge was removed for dewatering (55 FR 46372, November 2,

1990). Thus, wastewater from the sludge treatment system is excluded

from the definition of hazardous waste and its management is not within

the jurisdiction of RCRA.

B. Proposed Alternative Treatment Standards

If this treatability variance is finalized, Citgo Corporation may

renew the disposal of the treated sludge generated by the onsite

treatment system for sludges removed from the Surge Pond at the Lake

Charles Refinery site in a Subtitle C hazardous waste disposal facility

(since it remains a hazardous waste), subject to the following

conditions:

(1) The stabilized sludge generated by the treatment system must

meet the F037/F038 nonwastewater treatment standards for benzene,

chromium, and nickel and the NESHAP standard for benzene prior to

disposal in a subtitle C regulated facility. Treatment of benzene will

also result in incidental treatment of volatile organics in the waste.

Meeting LDR and NESHAP standards for benzene should also assure

optimized operation of the treatment process, since it is designed to

treat benzene. Other constituents that are normally regulated for F037/

F038 nonwastewaters are not regulated for this waste.

(2) The vapor control system must be operated in accordance with

performance specifications required by LDEQ, which state that the

thermal oxidizer fire box temperature shall be maintained at 1600 deg.F

or higher for one second or more. If the vapor control system

malfunctions, operation of the system must cease until the problem has

been corrected.

List of Subject in 40 CTR Part 268

Environmental protection, Hazardous Waste.

Dated: August 4, 1994.

Michael Shapiro,

Director, Office of Solid Waste.

For the reasons set out in the preamble, title 40, chapter I, of

the Code of Federal Regulations is proposed to be amended as follows:

PART 268--LAND DISPOSAL RESTRICTIONS.

1. The authority citation for part 268 continues to read as

follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921, and 6924.

2. Section 268.44 is amended by adding paragraph (p) to read as

follows:

Sec. 268.44 Variance from a treatment standard.

* * * * *

(p) Citgo Corporation may dispose the treated sludge generated by

the onsite treatment system for sludges removed from the Surge Pond at

the Lake Charles Refinery site in a Subtitle C hazardous waste disposal

facility, subject to the following conditions:

(1) The stabilized sludge generated by the treatment system must

meet the F037 and F038 nonwastewater treatment standards for benzene,

chromium, and nickel and the NESHAP standard for benzene. Other

constituents that are normally regulated in F037 and F038

nonwastewaters are not regulated for this waste.

(2) The vapor control system must be operated in accordance with

performance specifications required by Louisiana Department of

Environmental Quality, which state that the thermal oxidizer fire box

temperature shall be maintained at 1600 deg.F or higher for one second

or more. If the vapor control system malfunctions, operation of the

system must cease until the problem has been corrected.

Table A.--Characterization of Untreated Sludge

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Feasability study data Total conc. Variance petition

(mg/kg) data Total conc.

Chemical name --------------------------------------- (mg/kg) 4-day

Average High Low average

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Organics:

Acenaphthene...................................... 49.0 120.0 17.0 NA

Anthracene........................................ 33.0 65.0 7.0 23.37

Benz(a)anthracene................................. 44.9 160.0 7.1 17.02

Benzene........................................... 66.9 190.0 3.9 26.84

Benzo(a)pyrene.................................... 34.4 120.0 6.0 9.40

Chrysene.......................................... 73.9 220.0 16.0 29.36

Di-n-butyl phthalate.............................. ND ND ND 0.00

bis(2-Ethylhexyl)phthalate........................ ND ND ND 0.00

Ethylbenzene...................................... 135.0 300.0 32.0 37.36

Fluorene.......................................... 89.0 170.0 23.0 NA

Naphthalene....................................... 280.0 490.0 75.0 103.16

Phenanthrene...................................... 308.3 550.0 71.0 123.09

Phenol............................................ 32.0 46.0 ND 0.00

Pyrene............................................ 94.2 200.0 18.0 42.71

Toluene........................................... 182.3 490.0 ND 56.06

Xylenes (total)................................... 438.0 930.0 14.0 154.42

Inorganics:

Cyanides (total).................................. ND ND ND 10.11

Metals TCLP (mg/l)

Barium............................................ 389.0 613.0 207.0 NA

Chromium (total).................................. 1085.0 2330.0 268.0 3.10

Lead.............................................. 2200.0 5410.0 618.0 NA

Nickel............................................ 75.0 229.0 34.8 0.12

Vanadium.......................................... 324.0 962.0 34.0 NA

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NA--Not Analyzed.

ND--Not Detected.

Table B.--Treatment Performance Data

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Variance petition data 4-day average concentrations Worst case

----------------------------------------------------------------- sample

Chemical name Treated: system A Treated: system B ------------

Untreated ----------------------------------------------------

Dewatered Stabilized Dewatered Stabilized Stabilized

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Organics: Total (mg/kg)

Anthracene.................... 23.37 17.25 14.68 13.75 10.23 24.5

Benz(a)anthracene............. 17.02 13.78 14.25 11.39 8.43 22.9

Benzene....................... 26.84 *15.44 8.86 8.83 3.50 *19.8

Benzo(a)pyrene................ 9.40 7.62 6.87 6.28 5.47 12.8

Chrysene...................... 29.36 24.02 22.36 18.86 13.36 29.1

Di-n-butyl phthalate.......... 0.00 0.00 0.00 0.05 0.00 0.0

bis(2-Ethylhexyl)phthalate.... 0.00 8.24 15.66 2.63 0.00 81.1

Ethylbenzene.................. 37.36 31.10 27.00 25.03 17.39 35.4

Naphthalene................... 103.16 87.74 78.23 67.67 50.33 98.2

Phenanthrene.................. 123.09 109.33 96.33 82.47 65.41 119.0

Phenol........................ 0.00 1.80 0.00 0.00 0.00 0.0

Pyrene........................ 42.71 32.76 29.93 27.30 20.16 40.7

Toluene....................... 56.06 53.67 35.92 36.42 21.49 69.8

Xylenes (total)............... 154.42 158.34 123.86 112.35 84.94 173.4

Inorganics: Total (mg/kg)

Cyanides (total).............. 10.11 0.90 1.05 1.02 0.75 2.8

Metals: TCLP (mg/l)

Chromium (total).............. 3.10 0.04 0.04 0.39 0.04 0.04

Nickel........................ 0.12 0.04 0.04 0.15 0.04 0.04

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System A consists of filter presses followed by the Aran stabilization unit.

System B consists of centrifuges followed by the Portec stabilization unit.

*The company has agreed to continue treatment as required for treated wastes that do not meet the benzene NESHAP

level of 10 mg/kg.

[FR Doc. 94-21371 Filed 8-29-94; 8:45 am]

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