[Federal Register Volume 60, Number 21 (Wednesday, February 1, 1995)]
[Proposed Rules]
[Pages 6054-6067]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2499]



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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 261

[SW-FRL-5148-7]


Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; Proposed Exclusion

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule and request for comment.

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SUMMARY: The Environmental Protection Agency (EPA or Agency) is 
proposing to grant a petition submitted by the U.S. Department of 
Energy (DOE), Richland, Washington, to exclude certain wastes to be 
generated by a treatment process at its Hanford facility from being 
listed hazardous wastes. The Agency has concluded that the disposal of 
these wastes, after treatment, will not adversely affect human health 
or the environment. This action responds to a delisting petition 
submitted under Sec. 260.22, which specifically provides generators the 
opportunity to petition the Administrator to exclude a waste on a 
``generator-specific'' basis from the hazardous waste lists. This 
proposed decision is based on an evaluation of the treatment process 
and waste-specific information provided by the petitioner. If this 
proposed decision is finalized, the petitioned wastes will be 
conditionally excluded from the requirements of hazardous waste 
regulations under the Resource Conservation and Recovery Act (RCRA).
    The exclusion will allow DOE to proceed with critical cleanup at 
the Hanford site. The primary goal of cleanup is to protect human 
health and the environment by reducing risks from unintended releases 
of hazardous wastes that are currently stored at the site.
    The Agency is also proposing the use of a fate and transport model 
to evaluate the potential impact of the petitioned waste on human 
health and the environment, based on the waste-specific information 
provided by the petitioner. This model has been used to predict the 
concentration of hazardous constituents that may be released from the 
petitioned waste, at the time of disposal, which will not harm human 
health or the environment.

DATES: EPA is requesting public comments on today's proposed decision, 
the applicability of the fate and transport model used to evaluate the 
petitioned wastes, and on the verification testing conditions which 
will ensure that petitioned wastes are non-hazardous. Comments must be 
submitted by March 3, 1995. Because of an existing settlement agreement 
(consent order) on remediation of the Hanford site that requires DOE to 
have a final delisting in place by June 1995 or before, no extension to 
the comment period will be granted. Comments postmarked after the close 
of the comment period will be stamped ``late''.
    Any person may request a hearing on this proposed decision by 
filing a request with the Director, Characterization and Assessment 
Division, Office of Solid Waste, whose address appears below, by 
February 16, 1995. The request must contain the information prescribed 
in Sec. 260.20(d).

ADDRESSES: Send three copies of your comments to EPA. Two copies should 
be sent to the Docket Clerk, Office of Solid Waste (Mail Code 5305), 
U.S. Environmental Protection Agency, 401 M Street, S.W., Washington, 
D.C. 20460. A third copy should be sent to Jim Kent, Waste 
Identification Branch, CAD/OSW (Mail Code 5304), U.S. Environmental 
Protection Agency, 401 M Street, S.W., Washington, D.C. 20460. Identify 
your comments at the top with this regulatory docket number: ``F-95-
HNEP-FFFFF''.
    Requests for a hearing should be addressed to the Director, 
Characterization and Assessment Division, Office of Solid Waste (Mail 
Code 5304), U.S. Environmental Protection Agency, 401 M Street, S.W., 
Washington, D.C. 20460.
    The RCRA regulatory docket for this proposed rule is located at the 
U.S. Environmental Protection Agency, 401 M Street, S.W., Washington, 
D.C. 20460, and is available for viewing (Room M2616) from 9:00 a.m. to 
4:00 p.m., Monday through Friday, excluding Federal holidays. Call 
(202) 260-9327 for appointments. The public may copy material from any 
regulatory docket at no cost for the first 100 pages, and at a cost of 
$0.15 per page for additional copies.

FOR FURTHER INFORMATION CONTACT:
For general information, contact the RCRA Hotline, toll free at (800) 
424-9346, or at (703) 412-9810. For technical information concerning 
this notice, contact Narendra Chaudhari, Office of Solid Waste (Mail 
Code 5304), U.S. Environmental Protection Agency, 401 M Street, S.W., 
Washington, D.C. 20460, (202) 260-4787.

SUPPLEMENTARY INFORMATION:

Preamble Outline

I. Disposition of Delisting Petition
    A. Site History
    B. Petition for Exclusion
II. Background
    A. Authority
    B. Regulatory Status of Mixed Wastes
III. Proposed Exclusion
    A. Background
    1. Approach Used to Evaluate this Petition
    2. Overview of Treatment Process
    B. Agency Analysis
    C. Agency Evaluation [[Page 6055]] 
    D. Conclusion
    E. Verification Testing Conditions
IV. Effective Date
V. Regulatory Impact
VI. Regulatory Flexibility Act
VII. Paperwork Reduction Act
VIII. List of Subjects in 40 CFR Part 261

I. Disposition of Delisting Petition

U.S. Department of Energy's Hanford Facility, Richland, Washington

A. Site History

    In 1943, the U.S. Army Corps of Engineers selected the U.S. 
Department of Energy's (DOE) Hanford site located in Richland, 
Washington, as the location for reactor, chemical separation, and 
related activities in the production and purification of special 
nuclear materials. The site is situated on approximately 560 square 
miles (1,450 square kilometers), which is owned by the U.S. Government 
and managed by DOE. By the 1980s, environmental impacts resulting from 
operations at this site were acknowledged, and DOE initiated cleanup 
efforts. In May of 1989, DOE entered into a Tri-Party Agreement (``The 
Hanford Federal Facility Agreement & Consent Order''), with the State 
of Washington and the U.S. Environmental Protection Agency to initiate 
environmental restoration efforts over a 30-year period. As such, the 
current mission for DOE's Hanford facility is focused on waste 
management and environmental restoration and remediation. In order to 
carry out this mission (and allow for possible future use of the site 
after cleanup), it is critical for DOE's Hanford facility to obtain a 
delisting for certain wastes generated on-site. (See the public docket 
for the final report on The Future for Hanford: Uses and Cleanup, 
December 1992.)

B. Petition for Exclusion

    On October 30, 1992, DOE petitioned the Agency to exclude treated 
wastes generated from its proposed 200 Area Effluent Treatment Facility 
(ETF). DOE subsequently provided additional information to complete its 
petition and also submitted an addendum to the petition. The ETF is 
designed to treat process condensate (PC) from the 242-A Evaporator. 
The untreated PC is a low-level radioactive waste as defined in DOE 
Order 5820.2A and a RCRA listed hazardous waste (EPA Hazardous Waste 
Nos. F001 through F005 and F039 derived from F001 through F005) as 
defined in 40 CFR Sec. 261.31(a). DOE intends to discharge the treated 
effluents from the ETF to a Washington State Department of Ecology-
approved land disposal site. (See DOE's delisting petition and 
addendum, which are included in the public docket for this notice, for 
details regarding wastes being treated and treatment process.)
    While the constituents of concern in listed wastes F001, through 
F005 wastes include a variety of solvents (see Part 261, Appendix VII), 
the constituents (based on PC sampling data and process knowledge) that 
serve as the basis for characterizing DOE's petitioned wastes as 
hazardous were limited to 1,1,1-trichloroethane (F001), methylene 
chloride (F002), acetone and methyl isobutyl ketone (F003), cresylic 
acid (F004), and methyl ethyl ketone (F005).
    DOE petitioned the Agency to exclude its ETF generated liquid 
effluent because it does not believe that these wastes, once generated, 
will meet the listing criteria. DOE claims that its treatment process 
will generate non-hazardous wastes because the constituents of concern 
in the wastes are no longer present or will be present in insignificant 
concentrations. DOE also believes that the wastes will not contain any 
other constituents that would render it hazardous. Review of the 
petitioned wastes, except for the radioactive component which are 
regulated under the Atomic Energy Act (see Part II. Section B. below 
for details), included consideration of the original listing criteria, 
as well as the additional factors required by the Hazardous and Solid 
Waste Amendments (HSWA) of 1984. See Section 222 of HSWA, 42 U.S.C. 
6921(f), and Sec. 260.22(d)(2)-(4). Today's proposal to grant this 
petition for delisting is the result of the Agency's evaluation of 
DOE's petition.

II. Background

A. Authority

    On January 16, 1981, as part of its final and interim final 
regulations implementing Section 3001 of RCRA, EPA published an amended 
list of hazardous wastes from non-specific and specific sources. This 
list has been amended several times, and is published in Sec. 261.31 
and Sec. 261.32. These wastes are listed as hazardous because they 
typically and frequently exhibit one or more of the characteristics of 
hazardous wastes identified in subpart C of part 261 (i.e., 
ignitability, corrosivity, reactivity, and toxicity) or meet the 
criteria for listing contained in Sec. 261.11(a)(2) or (a)(3).
    Individual waste streams may vary, however, depending on raw 
materials, industrial processes, and other factors. Thus, while a waste 
that is described in these regulations generally is hazardous, a 
specific waste from an individual facility meeting the listing 
description may not be. For this reason, Sec. 260.20 and Sec. 260.22 
provide an exclusion procedure, allowing persons to demonstrate that a 
specific waste from a particular generating facility should not be 
regulated as a hazardous waste.
    To have their wastes excluded, petitioners must show that wastes 
generated at their facilities do not meet any of the criteria for which 
the wastes were listed. See Sec. 260.22(a) and the background documents 
for the listed wastes. In addition, the Hazardous and Solid Waste 
Amendments (HSWA) of 1984 require the Agency to consider any factors 
(including additional constituents) other than those for which the 
waste was listed, if there is a reasonable basis to believe that such 
additional factors could cause the waste to be hazardous. Accordingly, 
a petitioner also must demonstrate that the waste does not exhibit any 
of the hazardous waste characteristics (i.e., ignitability, reactivity, 
corrosivity, and toxicity), and must present sufficient information for 
the Agency to determine whether the waste contains any other toxicants 
at hazardous levels. See Sec. 260.22(a), 42 U.S.C. 6921(f), and the 
background documents for the listed wastes. Although wastes which are 
``delisted'' (i.e., excluded) have been evaluated to determine whether 
or not they exhibit any of the characteristics of hazardous waste, 
generators remain obligated under RCRA to determine whether or not 
their waste remains non-hazardous based on the hazardous waste 
characteristics.
    In addition, residues from the treatment, storage, or disposal of 
listed hazardous wastes and mixtures containing listed hazardous wastes 
are also considered hazardous wastes. See Secs. 261.3(a)(2)(iv) and 
(c)(2)(i), referred to as the ``mixture'' and ``derived-from'' rules, 
respectively. Such wastes are also eligible for exclusion and remain 
hazardous wastes until excluded. On December 6, 1991, the U.S. Court of 
Appeals for the District of Columbia vacated the ``mixture/derived 
from'' rules and remanded them to the Agency on procedural grounds 
(Shell Oil Co. v. EPA, 950 F.2d 741 (D.C. Cir. 1991)). On March 3, 
1992, EPA reinstated the mixture and derived-from rules on an interim 
basis, and solicited comments on other ways to regulate waste mixtures 
and residues (see 57 FR 7628). The Agency is going to address issues 
related to waste mixtures and residues in a future rulemaking.

B. Regulatory Status of Mixed Wastes

    The petitioned wastes that are subject to today's notice are 
``mixed wastes.'' Mixed wastes are defined as a mixture of hazardous 
wastes regulated under [[Page 6056]] Subtitle C of RCRA and radioactive 
wastes regulated under the Atomic Energy Act (AEA). Because section 
1004 of RCRA excludes ``source,'' ``special nuclear,'' and ``byproduct 
materials,'' as defined under the AEA, from the definition of RCRA 
``solid waste,'' there has been some confusion in the past as to the 
scope of EPA's authority over mixed waste under RCRA. EPA clarified 
this question in a Federal Register notice of July 3, 1986 (51 FR 
24504).
    EPA's clarification stated that the section 1004 exclusion applies 
only to the radioactive portion of mixed waste, not to the hazardous 
constituents. Therefore, a mixture of ``source,'' ``special nuclear,'' 
or ``byproduct materials'' and a RCRA hazardous waste must be managed 
as a hazardous waste, subject to the requirements of RCRA Subtitle C 
(that is, RCRA standards for the management of hazardous waste). EPA's 
oversight under RCRA, however, extends only to the hazardous waste 
components of the mixed waste, not to the source, special nuclear, or 
byproduct materials themselves. The exempted radionuclides are instead 
addressed under the AEA. DOE subsequently confirmed and clarified this 
interpretation in the Federal Register on May 1, 1987 (52 FR 15937).

III. Proposed Exclusion

A. Background

1. Approach Used to Evaluate This Petition
    This petition requests a delisting for listed hazardous wastes. In 
making the initial delisting determination, the Agency evaluated the 
petitioned wastes against the listing criteria and factors cited in 
Sec. 261.11(a)(2) and (a)(3). Based on this review, the Agency agreed 
with the petitioner that the wastes are non-hazardous with respect to 
the original listing criteria. (If the Agency had found that the wastes 
remained hazardous based on the factors for which the wastes were 
originally listed, EPA would have proposed to deny the petition.) EPA 
then evaluated the wastes with respect to other factors or criteria to 
assess whether there is a reasonable basis to believe that such 
additional factors could cause the wastes to be hazardous. The Agency 
considered whether the wastes are acutely toxic, and considered the 
toxicity of the constituents, the concentration of the constituents in 
the wastes, their tendency to migrate and to bioaccumulate, their 
persistence in the environment once released from the wastes, plausible 
and specific types of management of the petitioned wastes, the 
quantities of wastes generated, and variability of the wastes.
    For this delisting determination, the Agency used such information 
to identify plausible exposure routes (i.e., ground water, surface 
water, air) for hazardous constituents present in the petitioned 
wastes. The Agency determined that disposal in a land-based waste 
management unit is the most reasonable, worst-case scenario for DOE's 
wastes, and that the major exposure route of concern would be ingestion 
of contaminated ground water. The Agency notes that future land use on 
this site could change to private use and thus require protection of 
ground water resources (see the public docket for the final report on 
The Future for Hanford: Uses and Cleanup, December 1992). Therefore, 
the Agency is proposing to use a particular fate and transport model to 
establish maximum allowable concentrations of hazardous constituents 
for DOE's petitioned wastes. Specifically, the Agency used the model to 
estimate a dilution and attenuation factor (DAF) associated with the 
disposal of DOE's petitioned wastes in a land-based waste management 
unit, based on the estimated maximum annual volume of the wastes. The 
Agency used this DAF to back-calculate maximum allowable levels from 
the health-based levels for the constituents of concern.
    EPA believes that this fate and transport model represents a 
reasonable worst-case scenario for disposal of the petitioned wastes in 
a land-based waste management unit, and that a reasonable worst-case 
scenario is appropriate when evaluating whether wastes should be 
relieved of the protective management constraints of RCRA Subtitle C. 
The use of a reasonable worst case scenario results ensures that the 
wastes, once removed from hazardous waste regulation, will not pose a 
threat to human health or the environment.
    As an additional measure for evaluating this petition, the Agency 
believed that it should also consider the most likely disposal scenario 
for the petitioned wastes because these petitioned wastes are mixed 
wastes with limited disposal options. Therefore, EPA also evaluated the 
risks associated with the on-site disposal option selected by DOE, and 
accepted by the State of Washington, for the petitioned wastes. The 
preferred scenario is to pipe the treated waste effluents underground 
and discharge the effluents into a covered structure with an open 
bottom to the ground (i.e., a crib disposal system). DOE performed a 
ground water modeling study to assess the impacts of this disposal 
option. The results of DOE's ground water modeling study are discussed 
in Part III, Section C (Agency Evaluation).
    The Agency also considers the applicability of ground-water 
monitoring data during the evaluation of delisting petitions. In this 
case, the Agency determined that, because DOE is seeking an upfront 
delisting (i.e., an exclusion based on data from wastes generated from 
pilot-scale treatment processes), ground-water monitoring data 
collected from the areas where the petitioner plans to dispose of the 
waste in the future are not necessary. Because the petitioned wastes 
are not currently generated or disposed of, ground-water monitoring 
data would not characterize the effects of the petitioned wastes on the 
underlying aquifer at the disposal sites and, thus, would serve no 
purpose. Therefore, the Agency did not request ground-water monitoring 
data.
    DOE petitioned the Agency for an upfront exclusion (for wastes that 
have not yet been generated) based on descriptions of pilot-plant 
treatment processes used to treat samples comparable in composition to 
dilute aqueous hazardous waste streams at the Hanford facility, 
information about the sources of the dilute aqueous wastes that will be 
treated in the future, available characterization data for these 
wastes, and results from the analysis of treated effluent generated 
during studies of pilot-scale treatment processes.
    Similar to other facilities seeking upfront exclusions, this 
upfront exclusion (i.e., an exclusion based on information 
characterizing the process and wastes) would be contingent upon DOE 
conducting analytical testing of representative samples of the 
petitioned wastes once the treatment unit is on-line at the Hanford 
site. Specifically, DOE will be required to collect representative 
samples from its full-scale 200 Area Effluent Treatment Facility (ETF), 
once it is operational, to verify that the treatment system is on-line 
and operating as described in the petition. The verification testing 
requires DOE to demonstrate that the ETF, once constructed and on-line, 
will generate non-hazardous wastes (i.e., wastes that meet the Agency's 
verification testing conditions).
    From the evaluation of DOE's delisting petition, a list of 
constituents was developed for the verification testing conditions. 
Maximum allowable total constituent concentrations for these 
constituents were derived by back calculating from the delisting 
health-based levels through the proposed fate and transport model for a 
land-based management scenario. These concentrations (i.e., ``delisting 
levels'') [[Page 6057]] are the proposed verification testing 
conditions of the exclusion.
    The Agency encourages the use of upfront delisting petitions 
because they have the advantage of allowing the applicant to know what 
treatment levels for constituents will be sufficient to render specific 
wastes non-hazardous, before investing in new or modified waste 
treatment systems. Therefore, upfront delistings will allow new 
facilities to receive exclusions prior to generating wastes, which, 
without upfront exclusions, would unnecessarily have been considered 
hazardous. Upfront delistings for existing facilities can be processed 
concurrently during construction or permitting activities; therefore, 
new or modified treatment systems should be capable of producing wastes 
that are considered non-hazardous sooner than otherwise would be 
possible. At the same time, conditional testing requirements to verify 
that the delisting levels are achieved by the fully operational 
treatment systems will maintain the integrity of the delisting program 
and will ensure that only non-hazardous wastes are removed from 
Subtitle C control.
    Finally, the Hazardous and Solid Waste Amendments of 1984 
specifically require the Agency to provide notice and an opportunity 
for comment before granting or denying a final exclusion. Thus, a final 
decision will not be made until all public comments on today's proposal 
are addressed.
2. Overview of Treatment Process
    DOE's proposed treatment process for 242-A Evaporator PC consists 
of ten primary steps which are: (1) pH adjustment, (2) coarse 
filtration, (3) ultraviolet/oxidation (UV/OX), (4) pH adjustment, (5) 
hydrogen peroxide destruction, (6) fine filtration, (7) degasification, 
(8) reverse osmosis (RO), (9) ion exchange (IX), and (10) pH 
adjustment. DOE believes that efficient removals can be achieved 
through the proposed ETF for the remediation of 242-A Evaporator PC, 
and other liquid waste streams.
    DOE chose to perform 242-A Evaporator PC treatability studies using 
pilot-scale treatment equipment configured similarly to the ETF design. 
The pilot-scale treatability studies included ultraviolet/oxidation 
(UV/OX), reverse osmosis (RO), and ion exchange (IX) treatment steps in 
addition to several intermediate steps such as pH adjustment, hydrogen 
peroxide destruction, and fine filtration. In addition, since the 242-A 
Evaporator was not scheduled to be on-line until late 1993 or later, 
process condensate was not available for treatability studies in the 
pilot-scale treatment processes in sufficient time to meet the August 
1993 delisting submittal deadline. Therefore, DOE developed four 
surrogate test solutions (STSs) to characterize 242-A Evaporator PC, as 
well as other liquid wastes generated at the facility. DOE developed 
these four surrogate test solutions (i.e., STS-1 through STS-4) to 
evaluate the treatment capabilities of the ETF, in particular, the UV 
oxidation rate of organic compounds, and the removal efficiency of 
inorganic compounds using reverse osmosis and ion exchange. The STS 
constituents were selected from the 242-A Evaporator PC 
characterization data (obtained from 34 samples taken between August 
1985 and March 1989), a Hanford site chemical inventory, and additional 
organic compounds representing a variety of chemicals of regulatory 
concern. DOE believes that the 200 gallons of each batch of STS treated 
using the three main treatment processes (i.e., UV/OX, RO, and IX) in 
sequential steps provides pilot study capabilities with minimal infield 
scale-up issues. DOE's proposed full-scale ETF is designed to allow 
treatment of a wide range of constituents, in addition to those 
potentially present in the 242-A Evaporator PC.

B. Agency Analysis

    DOE provided information quantifying concentrations of hazardous 
constituents in 34 samples of untreated process condensate effluent 
collected between August 1985 and March 1989. These samples were 
analyzed for metals and other inorganic constituents, organic 
constituents, and radioactive constituents. DOE used Methods SW-846 
6010 to quantify concentrations of the TC metals and other inorganic 
constituents. DOE used Methods 8240 and 8270 to quantify concentrations 
of the volatile and semi-volatile organic constituents, and Method 9010 
to quantify the total constituent concentrations of cyanide in the 242-
A Evaporator PC. Radioactive constituents were analyzed using Method 
9310. Table 1 presents 90th percentile upper confidence limit (90%CI) 
and maximum concentrations of hazardous constituents of concern 
detected in the 34 samples of 242-A Evaporator PC collected between 
August 1985 and March 1989.
    Table 1 includes all hazardous constituents (listed in App. VIII, 
Sec. 261) found in the condensate, as well as other detected 
constituents of concern that have health-based levels. Other 
constituents detected without health-based levels included inorganic 
salts (e.g., sodium, calcium) and organic compounds (e.g., alcohols, 
hydrocarbons, glycols) of relatively low toxicity. (See the public 
docket for this notice for a summary of constituents detected and 
health-based levels.)

 Table 1.--Hazardous Constituents of Concern Detected in Untreated 242-A
                           Evaporator PC (PPM)                          
------------------------------------------------------------------------
                                                           Constituent  
                                                         concentrations 
                       Parameter                       -----------------
                                                         90% CI  Maximum
------------------------------------------------------------------------
Barium................................................   0.0072   0.008 
Cadmium...............................................  SD        0.005 
Chromium..............................................   0.066    0.156 
Fluoride..............................................   0.971   12.27  
Mercury...............................................   0.0003   0.0007
Nickel................................................   0.015    0.017 
Vanadium..............................................   0.0067   0.007 
Zinc..................................................   0.017    0.044 
Acetone...............................................   1.0      5.1   
Benzaldehyde..........................................  SD        0.023 
Benzyl alcohol........................................   0.014    0.018 
1-Butanol.............................................  11.0     88.0   
Chloroform............................................   0.014    0.027 
Methyl ethyl ketone...................................   0.053    0.12  
Methylene chloride*...................................   0.14     0.18  
Methyl isobutyl ketone................................   0.014    0.068 
N-Nitrosodimethylamine................................  SD        0.057 
Phenol................................................  SD        0.033 
Pyridine..............................................  SD        0.55  
1,1,1-Trichloroethane*................................  SD        0.005 
------------------------------------------------------------------------
SD Denotes a single detect.                                             
*Constituent confirmed to be in blank samples only.                     

    For the ETF treatability studies, DOE used SW-846 methods 8015 and 
8240 for analysis of STS protocol characterization samples, with one 
exception. The semivolatile organic compound analysis was performed 
using a Contract Laboratory Program (CLP) analysis method, a method 
similar to SW-846 Method 8270. DOE used SW-846 Method 9010 to quantify 
the total constituent concentrations of cyanide in samples of the 
untreated and treated STSs.
    Tables 2 through 5 present concentrations of inorganic and organic 
compounds in samples of untreated and treated STS-1 through STS-4 and 
percent removals. Nearly all of the 29 inorganic constituents were 
treated to below their detection levels based on the inorganic data for 
the STSs from the IX process; only inorganic constituents above 
detection limits are included in the tables. Treated values for organic 
constituents are based on the organic data for the STSs from the UV/OX 
process only. To fully illustrate the capabilities of the UV/OX system, 
all meaningful data for organic constituents are given in the tables.

                                                                        
[[Page 6058]]                                                           
  Table 2.--Total Constituent Concentrations (ppm) STS-1, Untreated and 
                                 Treated                                
------------------------------------------------------------------------
                                          Constituent concentrations    
             Parameter              ------------------------------------
                                      Untreated    Treated    % removal 
------------------------------------------------------------------------
Aluminum...........................       5.63      0.20              96
Ammonium...........................   2,175.6       0.079            100
Barium.............................       0.22      0.0075            97
Chloride...........................       0.014     0.00024           98
Fluoride...........................       0.02      0.0002            99
Mercury............................       0.095     0.00033          100
Nitrate............................       1.11      0.00022          100
Selenium...........................       1.24      0.0048           100
Acetone............................      14.0      <0.01             100
Benzene............................       1.7       0.001            100
1-Butanol..........................     120.0      <0.1              100
Carbon tetrachloride...............       0.480     0.002            100
Chloroform.........................       1.9       0.029             98
Methyl ethyl ketone................       5.3      <0.01             100
Methyl isobutyl ketone.............       5.8      <0.01             100
Naphthalene........................       1.9      <0.01             >99
Toluene............................       1.0      <0.005            100
1,1,1-Trichloroethane..............       1.3       0.0016            99
Phenol.............................       2.7      <0.01             100
Tributyl Phosphate.................      15.0      <0.02             100
Tridecane..........................       0.78      0.023             97
------------------------------------------------------------------------
99
Methyl isobutyl ketone............       0.47     <0.01              >98
Naphthalene.......................       0.17      0.016              91
Toluene...........................       0.16     <0.01              >94
1,1,1-Trichloroethane.............       0.15     <0.005             >97
Phenol............................       0.21     <0.01              >95
Tributyl Phosphate................       8.0      <0.02              100
Tridecane.........................       0.53      0.072             86 
------------------------------------------------------------------------
< Constituent below detection limit; % minimum removal calculated by    
  assuming constituent is at the detection limit.                       


  Table 4.--Total Constituent Concentrations (ppm) STS-3, Untreated and 
                                 Treated                                
------------------------------------------------------------------------
                                          Constituent Concentrations    
             Parameter              ------------------------------------
                                     Untreated    Treated     % removal 
------------------------------------------------------------------------
Ammonium...........................   35.9         0.15              100
Chloride...........................    0.00065     0.000078           88
Fluoride...........................    0.0052      0.000069           99
Nitrate............................    0.048       0.0004             99
Selenium...........................    0.94        0.0057             99
Acetone............................    1.8        <0.01              >99
Benzene............................    0.016       0.013              99
1-Butanol..........................    7.1        <0.1               >99
Carbon tetrachloride...............    0.15        0.019              87
Chloroform.........................    0.29        0.006              98
Methyl ethyl ketone................    0.078      <0.01              >87
Methyl isobutyl ketone.............    0.39        0.01              97 
[[Page 6059]]                                                           
                                                                        
Naphthalene........................    0.13       <0.01              >92
Toluene............................    0.18       <0.005             >97
1,1,1-Trichloroethane..............    0.24        0.005              98
Phenol.............................    0.18       <0.01              >94
Tributyl Phosphate.................    4.9        <0.02              100
Tridecane..........................    0.13        0.15              NM 
------------------------------------------------------------------------
< Constituent below detection limit; % minimum removal calculated by    
  assuming constituent is at the detection limit.                       
NM Data for tridecane not meaningful due to solubility problems.        


  Table 5.--Total Constituent Concentrations (ppm) STS-4, Untreated and 
                                 Treated                                
------------------------------------------------------------------------
                                          Constituent concentrations    
             Parameter              ------------------------------------
                                      Untreated    Treated    % removal 
------------------------------------------------------------------------
Ammonium...........................   2,047.0       0.74             100
Chloride...........................       0.017     0.00042           98
Fluoride...........................       0.024     0.0003            99
Mercury............................       0.075     0.0012            98
Nitrate............................       1.06      0.00064          100
Acrolein...........................       2.4       0.02              99
Aniline............................       2.7      <0.02             >99
Bis (2-chloroethyl) ether..........       1.7      <0.01             >99
Bis(2-ethylhexyl)phthalate.........       0.059     0.014             76
1-Butanol..........................       8.9      <0.1              >99
1, 4-Dichlorobenzene...............       1.9      <0.01              99
gamma-BHC..........................       1.4       0.19              86
Hexachloroethane...................       0.93      0.57              39
Nitrobenzene.......................       3.3      <0.01             100
N-Nitroso-di-n-propylamine.........       1.45     <0.01              99
Pentachlorophenol..................       1.5      <0.02              99
Tetrachloroethylene................       1.2       0.24              80
Tetrahydrofuran....................       5.3      <0.005            100
Tributyl phosphate.................       4.8      <0.02             100
1,1, 2-Trichloroethane.............       2.4       1.0               58
Tridecane..........................       0.36      0.14             61 
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