[Federal Register Volume 64, Number 184 (Thursday, September 23, 1999)]
[Notices]
[Pages 51540-51543]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24842]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6442-9]


Land Disposal Restrictions: Notice of Intent To Grant a Site-
Specific Determination of Equivalent Treatment to Pioneer Chlor-Alkali, 
Inc.

AGENCY: Environmental Protection Agency.

ACTION: Notice of intent to grant petition.

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SUMMARY: The United States Environmental Protection Agency is 
announcing our intent to grant the petition of Pioneer Chlor-Alkali, 
Inc. in St. Gabriel, Louisiana for a site-specific determination of 
equivalent treatment (DET). This DET would address Pioneer's Remerc 
process for treating K106 mercury wastes under the Resource 
Conservation and Recovery Act (RCRA).
    The proposed DET would recognize Remerc, a hydrometallurgical 
process, as an equivalent technology to roasting or retorting with 
recovery of mercury for reuse, our current land disposal restrictions 
(LDR) hazardous waste treatment standard for high mercury K106 waste 
(wastewater treatment sludge from the mercury cell process used in 
chlorine production). If we grant this DET, Pioneer will be allowed to 
use Remerc to treat high mercury K106 wastes, and the treatment 
residuals will be subject to a mercury limit of 0.20 mg/L TCLP.

DATES: This DET is effective on October 25, 1999, unless we receive 
relevant adverse comment by October 14, 1999. If we receive such 
comment(s), we will publish a timely notice in the Federal Register 
informing the public that this DET will not be automatically granted 
and indicating the further steps that will be taken.

ADDRESSES: Commenters must send an original and two copies of their 
comments referencing Docket Number F-99-PCAP-FFFFF to: RCRA Docket 
Information Center, Office of Solid Waste (5305G), U.S. Environmental 
Protection Agency Headquarters (EPA, HQ), 401 M Street, SW, Washington, 
DC 20460. Hand deliveries of comments should be made to the Arlington, 
VA, address below. Comments may also be submitted electronically 
through the Internet to: [email protected]. Comments in 
electronic format should also be identified by the docket number F-99-
PCAP-FFFFF. All electronic comments must be submitted as an ASCII file 
avoiding the use of special characters and any form of encryption.
    Commenters should not submit electronically any confidential 
business information (CBI). An original and two copies of CBI must be 
submitted under separate cover to: RCRA CBI Document Control Officer, 
Office of Solid Waste (5305W), U.S. EPA, 401 M Street, SW, Washington, 
DC 20460.
    Public comments and supporting materials are available for viewing 
in the RCRA Information Center (RIC),

[[Page 51541]]

located at Crystal Gateway I, First Floor, 1235 Jefferson Davis 
Highway, Arlington, VA. The RIC is open from 9 a.m. to 4 p.m., Monday 
through Friday, excluding federal holidays. To review docket materials, 
it is recommended that the public make an appointment by calling (703) 
603-9230. The public may copy a maximum of 100 pages from any 
regulatory docket at no charge. Additional copies cost $0.15/page. The 
index and some supporting materials are available electronically. See 
the Supplementary Information section for information on accessing 
them.
    Background information for this document is available on the 
Internet. Follow the instructions below to access these materials 
electronically:

WWW: http://www.epa.gov/epaoswer/hazwaste/ldr
FTP: ftp.epa.gov
Login: anonymous
Password: your Internet address

    Files are located in /pub/epaoswer

    The official record for this action will be kept in paper form. 
Accordingly, we will transfer all comments received electronically to 
paper form and place them in the official record.
    The official record also will include all comments submitted in 
writing.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
RCRA Hotline at 800 424-9346 or TDD 800 553-7672 (hearing impaired). In 
the Washington, DC, metropolitan area, call (703) 412-9810 or TDD (703) 
412-3323. For more detailed information on specific aspects of this 
document, contact Josh Lewis at (703) 308-7877 or [email protected], 
Office of Solid Waste (5302 W), U.S. Environmental Protection Agency, 
401 M Street SW, Washington, DC 20460.

SUPPLEMENTARY INFORMATION:

I. Overview of Today's Action

    In this document, EPA is informing the public of its intent to 
grant the petition of Pioneer Chlor-Alkali, Inc. (``Pioneer'') for a 
site-specific determination of equivalent treatment (DET) for its 
Remerc process, a nonthermal mercury recovery process. Pioneer uses the 
Remerc process to treat its K106 waste, which is a wastewater treatment 
sludge from the mercury cell process used in chlorine production. Under 
current Resource Conservation and Recovery Act (RCRA) waste treatment 
regulations, the residuals from the Remerc process must be at or below 
0.025 mg/L, as measured by the toxicity characteristic leaching 
procedure (TCLP), because these residuals, as generated, usually do not 
contain the 260 mg/kg total mercury necessary for effective use of 
roasting or retorting. If the wastes exceed 0.025 mg/L TCLP, Pioneer 
must retreat the residuals until they meet the standard. However, 
Pioneer may not retreat any of its Remerc residuals that have 
concentrated the mercury to a concentration above 260 mg/kg total 
mercury, because they are now high mercury subcategory wastes, for 
which the standards require the use of roasting or retorting 
(``RMERC''), a thermal process.1
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    \1\ Because the Remerc process is situated between the 
wastewater collection tank and the Shriver filter press, the waste 
initially being treated by the Remerc system is not actually K106 
waste, because there is no point of generation until after the 
filter press. See section IV of this document for a complete 
description of Pioneer's treatment system. After the Shriver filter 
press, the waste is usually low mercury subcategory K106 waste, for 
which the mercury treatment standard is a TCLP of 0.025 mg/L. 
Occasionally, the residuals from Remerc treatment are above 260 mg/
kg total mercury. In this case, at the point of generation, the 
waste is high mercury subcategory, which requires RMERC.
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    If we grant this DET, we would recognize Remerc at Pioneer's 
facility as equivalent to RMERC. Pioneer would then be allowed to use 
Remerc to retreat its K106 high mercury residuals. Also, by virtue of 
this DET, Remerc residuals will be subject to 0.20 mg/L TCLP, which is 
the level that RMERC treatment residuals must meet.
    We intend to grant this DET because Pioneer has adequately 
demonstrated that Remerc is equivalent to RMERC for the treatment of 
K106 wastes. This demonstration is based primarily on the following key 
factors: (1) Remerc has a comparable mercury recovery rate; (2) Remerc 
residuals are consistent with retort residuals, both in terms of total 
mercury content and mercury TCLP concentration; and (3) Remerc releases 
negligible amounts of mercury to the air and water.
    Although we have not typically published DETs in the Federal 
Register for comment in the past, EPA wants to encourage the maximum 
amount of public involvement in our decision making. Therefore, we are 
publishing this document with a 21-day comment period. If we do not 
receive any adverse comments on this proposed DET, the DET will 
automatically take effect 30 days after the date of this document. 
However, if we do receive adverse comment(s), we will publish a timely 
notice in the Federal Register informing the public that this DET will 
not be automatically granted and indicating the further steps that will 
be taken.

II. What Is a Determination of Equivalent Treatment (DET)?

    Under section 3004(m) of RCRA, 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 
implements section 3004(m) by establishing treatment standards based on 
the performance of best demonstrated available technology (BDAT). This 
approach was upheld by the DC Circuit in Hazardous Waste Treatment 
Council v. EPA, 886 F.2d 355 (D.C. Cir. 1989).
    When setting LDR treatment standards, we have generally established 
two types: (1) a numerical, concentration-based treatment limit for 
each constituent of concern, or (2) a method of treatment that must be 
used to treat a particular constituent or constituent(s). In either 
case, the treatment standard is based on the BDAT.
    Under the second approach where a technology is specified as the 
treatment standard, EPA allows facilities to submit petitions (or 
applications) demonstrating that an alternative treatment method can 
achieve a measure of performance equivalent to that achievable by the 
EPA-specified method. This demonstration of equivalency, known as a 
Determination of Equivalent Treatment (DET) if approved, is typically 
both waste-specific and site-specific. Our approval is based on: (1) 
Demonstrations of equivalence for an alternative method of treatment 
based on a statistical comparison of technologies, including a 
comparison of specific design and operating parameters; (2) the 
development of a concentration-based standard that utilizes a surrogate 
or indicator compound that guarantees effective treatment of the 
hazardous constituents; and (3) the development of a new analytical 
method for quantifying the hazardous constituents.2 Thus, in 
determining whether a technology is equivalent to the specified 
technology, EPA carefully evaluates the treatment process, including 
examining the characteristics of the residuals that are generated, and 
compares the performance of this alternative treatment process to the 
specified method of treatment. We also look at any other potential 
adverse environmental impacts, including releases to air and water. See 
Chemical Waste Management v. EPA, 976 F.2d 2, 17 (D.C. Cir. 1992), 
explaining the

[[Page 51542]]

relevance of assessing releases to media other than land in determining 
whether treatment is minimizing threats, as required by RCRA section 
3004 (m).
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    \2\ See 40 CFR 268.42(b) and the preamble for the Third Third 
Scheduled Wastes; Final Rule (55 FR 22536, June 1, 1990) for more 
information.
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III. What Is the Current Treatment Standard for K106 Mercury 
Wastes?

    EPA established treatment standards for K106 waste (wastewater 
treatment sludge from the mercury cell process used in chlorine 
production) as part of the LDR Third Third final rule (55 FR 22569, 
June 1, 1990). In this rule, EPA established two treatment 
subcategories for all mercury waste codes: a high mercury subcategory 
for wastes with a total mercury concentration greater than or equal to 
260 mg/kg; and a low mercury subcategory for wastes with a total 
mercury concentration less than 260 mg/kg.
    High mercury subcategory K106 wastes are required to be treated by 
roasting or retorting with recovery of mercury for reuse (``RMERC''). 
RMERC residues must then meet a numerical mercury treatment standard of 
0.20 mg/L TCLP. Low mercury subcategory K106 wastes (that are 
themselves not RMERC residues) are not subject to a specific treatment 
technology and must only meet a numerical treatment standard of 0.025 
mg/L mercury TCLP.

IV. Analysis of the Pioneer Application

A. The Grounds Presented by Pioneer

    1. Description of Pioneer's K106 Waste and the Remerc process
    The subject wastes are classified as K106 nonwastewaters, treatment 
sludges from wastewater systems that are part of the mercury cell 
process in chlorine production. Pioneer generates between 176 and 244 
tons of these K106 wastes per year when manufacturing chlorine and 
caustic soda. In its application for a DET, Pioneer provides the 
following description of its Remerc process.3
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    \3\ See Pioneer's Application for a Determination of Equivalent 
Treatment, which is in the docket to today's document, for more 
information on the Remerc process, including a flow diagram.
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    ``Mercury containing wastewater from various areas of the St. 
Gabriel plant is generated at a rate of approximately 65 million 
gallons per year. This wastewater is collected in an equalization tank. 
The wastewater is pumped from the equalization tank to a series of 
treatment tanks where sodium hydrosulfide (NaHS) is added and the pH 
adjusted to form a mercury sulfide precipitate. The wastewater is then 
directed to a Lamella settler, where the mercury sulfide particles 
concentrate toward the bottom while nearly particle-free water flows to 
the filter (called the sluicing filter) where remaining particles are 
removed. The wastewater then flows through a carbon tower for final 
treatment before being discharged to the Mississippi River under the 
plant's NPDES/LPDES water discharge permit. The entire system consists 
of tank units connected by a pipe.
    ``Prior to 1996, the bottoms of the Lamella settler were pumped to 
a collection tank, as were solids (principally diatomaceous earth 
filter aid) back-flushed from the sluicing filters. The combined 
wastewater stream, containing approximately 10-15% solids, was then 
pumped to a Shriver filter press (a pressure leaf filter) for solids 
removal. The solids were then removed from the Shriver filter as a 
wastewater treatment sludge. The sludge generated at the Shriver filter 
was a high mercury K106 hazardous waste containing approximately 1.5-2% 
mercury. * *. *.
    ``In upgrading the wastewater treatment system in 1996, the Remerc 
system was added between the wastewater collection tank and the Shriver 
filter press. The combined wastewater from the bottom of the Lamella 
settler and the back-flushing of the sluicing filters is now pumped to 
a leach tank, where a counter-current leaching solution removes a large 
percentage of the mercury. The leach solution then flows to a 
cementation stage, where metallic mercury is recovered and returned to 
the manufacturing process. The wastewater containing suspended solids 
continues to a thickener, which increases the solids content from 
approximately 2% to 6-10%. This stream then continues through a second 
leach tank, where more mercury is removed, and a second thickener. The 
stream then proceeds to a surge tank where NaHS is added to bind any 
remaining mercury, then to the Shriver filter press for solids removal 
and washing.'' 4 The Shriver filter press sludge is K106 
waste.
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    \4\ Mercury sulfide is the most insoluble of the mercury 
complexes. However, it can become soluble if two conditions are 
present: the surrounding environment is alkaline, and excess sulfide 
is present. The washing step at the end of the treatment process 
removes any excess sulfide from the K106 waste prior to disposal.
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2. Description of Test Results
    As part of its application, Pioneer submitted data on Remerc-
treated waste from February 4 to March 31, 1999. Excluding data 
gathered during a process upset from March 15-18, 1999, the average 
total mercury content in the Remerc residuals is about 150 mg/kg, with 
an average TCLP concentration of 0.021 mg/L. Using the BDAT 
methodology,5 we find that RMERC residuals could meet a 
treatment standard of 0.046 mg/L TCLP.6
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    \5\ BDAT Background Document for Quality Assurance/Quality 
Control Procedures and Methodology, October 23, 1991.
    \6\ See Memo from Josh Lewis, USEPA, to the Record, June 23, 
1999 for the calculation of the Remerc residual standard using data 
submitted by Pioneer.
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    To calculate the mercury recovery rate, we looked at Pioneer's 
historical data showing the mercury concentrations in the untreated 
wastes,7 and we compared these data to data from Remerc-
treated waste that were presented in Pioneer's DET application. 
Pioneer's historical data are from samples taken in 1993, 1994 and 
1995, before the insertion of the Remerc process in 1996, and from 1997 
when Pioneer had to bypass the Remerc process after it had been 
installed.8 The data show that Pioneer's untreated K106 
waste is relatively consistent in terms of its total mercury content. 
The average mercury removal rate of the Remerc process is about 99%. 
During the worst case scenario (i.e., when the untreated K106 waste had 
a mercury content of 9100 mg/kg), the Remerc process removes about 
98.4% of the mercury.
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    \7\ As explained above, the Remerc process is situated between 
the wastewater collection tank and the Shriver filter press. Because 
of this set-up, Pioneer does not generate a K106 waste until the 
majority of the mercury is already removed from the waste (in 
contrast, at chlor-alkali facilities with on-site retort units, the 
K106 waste that will be generated after the filter press will still 
have all of the mercury in it). Taking this into account, we believe 
the best way to calculate the mercury recovery rate is to look at 
historical data showing the mercury concentrations in the untreated 
K106 wastes, and compare them to the mercury concentrations in the 
treated waste from the Pioneer DET application.
    \8\ See the August 11, 1999 letter from Dana Oliver, Pioneer, to 
Josh Lewis, USEPA for all of Pioneer's untreated K106 waste data.
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3. Pioneer's Request for Relief
    In its application, Pioneer asserts that its K106 Remerc residual 
is analogous to the K106 retort residue in that both wastes have 
similar total mercury and TCLP mercury levels, and both wastes are 
residues from processes designed to recover mercury for reuse. 
Furthermore, Pioneer notes that mercury emissions from Remerc to other 
media, including air and water, are negligible. However, Remerc 
residues are currently subject to an LDR standard of 0.025 mg/L TCLP, 
while retort residues have to meet a less stringent mercury TCLP of 
0.20 mg/L. Furthermore, Remerc residues that are above 260 mg/kg total 
mercury are considered high mercury wastes, for which the current 
treatment standard is retorting, and not Remerc.
    Pioneer requests a Hazardous Waste Determination of Equivalent 
Treatment

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(DET) that: (1) Recognizes its Remerc process as equivalent to RMERC, 
so that Remerc can treat high mercury K106 wastes; and (2) subjects 
Remerc residues to a standard of 0.20 mg/L TCLP, the same as retorting 
residues. The Remerc residues will continue to be disposed in a 
subtitle C landfill because they remain a listed hazardous waste.
    See Pioneer's Application for Determination of Equivalent 
Treatment, which can be found in the docket to today's document, for 
more details on Pioneer's request.

B. How Does Pioneer Satisfy the Criteria?

    After careful review of the data and application submitted by 
Pioneer, we conclude that Pioneer has adequately demonstrated that its 
Remerc process is an equivalent treatment method to RMERC. We therefore 
propose to grant Pioneer's petition for the following reasons:
    (1) Remerc removes comparable amounts of mercury from its K106 
wastes. As mentioned above, Pioneer's Remerc process reduces the 
mercury content from about 15,000 mg/kg to about 150 mg/kg, which is a 
removal rate of about 99%. Both the mercury concentration in the 
untreated K106 and the mercury recovery rate are similar to the 
information presented in the ``Final Best Demonstrated Available 
Treatment (BDAT) Background Document for Mercury-Containing Wastes 
D009, K106, P065, P092, and U151'' (May 1990) and the Third Third final 
rule preamble (55 FR 22570, June 1, 1990). The BDAT Background Document 
states that K106 generated by sulfide precipitation contains 
approximately 4.4% mercury on average as mercury sulfide, with a range 
of 0.5% to 16% mercury. The Third Third final rule preamble states 
that, based on data from the thermal processing of cinnabar ores and 
the retorting or roasting of a mixture of K071 and K106 wastes, mercury 
retorting can recover 98-99% of mercury contained in the feed material.
    (2) Remerc residues are consistent with RMERC residues. The Remerc 
residual's average mercury content of 150 mg/kg and its average TCLP of 
0.021 mg/L are consistent with the data from the roasting and retorting 
of mercury-containing wastes in four processes examined during our BDAT 
evaluation.9 The BDAT Background Document presents data from 
a thermal recovery system that processes mercuric sulfide ores for 
mercury recovery, a retorter treating K106 hydrazine sludge, a retorter 
treating a combined K071/K106 waste, and a retorter treating a K106 
waste generated by sodium borohydride reduction and filtration. 
Furthermore, because Remerc residuals consistently have a total mercury 
content below 260 mg/kg and can achieve a TCLP well below the 0.20 mg/L 
limit, Remerc is operating in a manner consistent with the four BDAT 
retort units.
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    \9\ See the BDAT Background Document, which can be found in the 
docket supporting today's document, for the complete data sets from 
the roasting and retorting of these mercury-containing wastes.
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    (3) Remerc does not release mercury to other environmental media. 
With regard to other possible environmental releases of mercury, air 
emissions from Remerc are negligible, as the entire Remerc system is 
enclosed and vented to a scrubber system, and the process is 
nonthermal. Stack sampling conducted in 1999 confirmed that less than 
0.033 grams of mercury are released from the scrubber to the air per 
day.10 Furthermore, the Remerc system does not appear to 
adversely affect surrounding water bodies. Total mercury emissions to 
surrounding water bodies were 18 pounds both in 1995, the last full 
year before start-up of the Remerc process, and again in 1998, with the 
Remerc system in place.
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    \10\ See appendix IV of Pioneer's Application for a 
Determination of Equivalent Treatment, which contains the 
hypochlorite scrubber stack sampling report.
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    (4) Other factors. In addition, Pioneer has also taken advantage of 
pollution prevention opportunities where possible. For example, the 
Remerc system uses spent sulfuric acid and hypochlorite solution from 
the tail gas neutralizer as reagents, which is beneficial use of 
byproduct materials from the main process.

C. Conditions of the Proposed DET

    If we grant this DET, the following conditions would apply: (1) 
Remerc residuals at Pioneer's facility would have to meet a TCLP of 
0.20 mg/L; (2) if Pioneer generates a high mercury subcategory K106 
waste, it can be treated using the Remerc process; (3) after treatment 
to a mercury concentration of 0.20 mg/L TCLP, Pioneer may dispose of 
the treated K106 wastes in a RCRA subtitle C landfill assuming they 
meet any other applicable LDR treatment standards; (4) compliance with 
these standards would not relieve the facility from compliance with any 
other applicable treatment standards associated with this waste, 
including other applicable federal, state, or local requirements as 
specified in the facility's waste analysis plan; and (5) this DET would 
have no expiration date.
    With regard to condition #5, one option we considered was whether 
to have this DET expire after a certain time period because we are 
currently reevaluating all of the mercury LDR treatment standards, 
including the standards for RMERC and other treatment 
residuals.11 We do not feel this expiration date is 
necessary because we will be examining the residuals from all mercury 
recycling technologies (e.g., RMERC and Remerc). If we change the 
residual treatment standard for some or all of these technologies, we 
will address the appropriate standard for Pioneer's Remerc residuals as 
well.

    \11\ See our ANPRM for a description of the issues we have with 
the current standards (64 FR 28949, May 28, 1999).

    Dated: September 9, 1999.
Elizabeth A. Cotsworth,
Director, Office of Solid Waste.
[FR Doc. 99-24842 Filed 9-22-99; 8:45 am]
BILLING CODE 6560-50-P