[Federal Register Volume 64, Number 149 (Wednesday, August 4, 1999)]
[Rules and Regulations]
[Pages 42552-42573]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-18604]



[[Page 42551]]

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Part IV





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 403 and 503



Standards for the Use or Disposal of Sewage Sludge; Final Rule

  Federal Register / Vol. 64, No. 149 / Wednesday, August 4, 1999 / 
Rules and Regulations  

[[Page 42552]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 403 and 503

[FRL-6401-3]
RIN 2040-AC25


Standards for the Use or Disposal of Sewage Sludge

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Today's action amends the existing regulation regarding the 
land application, surface disposal, and incineration of sewage sludge. 
The amendments clarify existing regulatory requirements regarding 
operational standards for pathogen and vector attraction reduction and 
provide flexibility to the permitting authority and the regulated 
community in complying with the minimum frequency of monitoring 
requirements. The amendments also make the incineration subpart of the 
regulation totally self-implementing by providing information on air 
dispersion modelling, incinerator testing methods, and continuous 
emission monitors to the sewage sludge incinerator owner-operator. It 
also amends the existing General Pretreatment Regulation for Existing 
and New Sources of Pollution by adding a concentration for total 
chromium in land-applied sewage sludge to the list of pollutants that 
are eligible for a removal credit issued by a wastewater treatment 
works treating domestic sewage.

EFFECTIVE DATE: The final rule is effective September 3, 1999. For 
purposes of judicial review, this final rule is promulgated as of 1 pm 
eastern time on August 18, 1999 as provided in 40 CFR 23.7.

FOR FURTHER INFORMATION CONTACT: Alan B. Rubin, Ph.D., Senior 
Scientist, Health and Ecological Criteria Division (4304), Office of 
Science and Technology, U.S. Environmental Protection Agency, 401 M 
Street, SW, Washington, DC 20460, telephone (202) 260-7589.

SUPPLEMENTARY INFORMATION:
I. Regulated Entities
II. Authority
III. Background
IV. Final Amendments to the Part 503 Land Application, Surface 
Disposal, Pathogen, and Vector Attraction Reduction Requirements
    A. Ceiling Concentration Limits--Land Application
    B. Frequency of Monitoring
    C. Certification Language
    D. Time of Application
    E. Definition of pH
    F. Class B, Alternative 1--at the Time of Use or Disposal
    G. Site Restriction for Grazing of Animals
    H. Vector Attraction Reduction Equivalency
    I. Vector Attraction Reduction at the Time of Use or Disposal
    J. Time Period for Vector Attraction Reduction Option 10
    K. Technical Corrections
    1. Sections 503.16(a)(1) and 503.26(a)(1)--Frequency of 
Monitoring
    2. Section 503.17(b)(7)--Recordkeeping for Land Application of 
Domestic Septage
    3. Section 503.18--Reporting
    4. Section 503.21(c)--Contaminate An Aquifer
    5. Section 503.22(b)--General Requirements
    6. Section 503.32(a)(3)--Pathogens
    7. Appendix B to Part 503--Pathogen Treatment Processes
V. Final Amendments to the Part 503 Incineration Requirements
    A. Compliance period
    B. Site-Specific Exemption from Frequency of Monitoring, 
Recordkeeping, and Reporting Requirements
    C. Pollutant Limits for Arsenic, Cadmium, Chromium, Lead and 
Nickel
    D. Management Practices
    E. Frequency of Monitoring
    F. Recordkeeping
VI. Final Amendment to Part 403
VII. Regulatory Requirements
    A. Executive Order 12866, Regulatory Planning and Review
    B. Regulatory Flexibility Act
    C. Congressional Review Act
    D. Paperwork Reduction Act
    E. Unfunded Mandate Reform Act
    F. Executive Order 12875, Enhancing Intergovernmental 
Partnerships
    G. Executive Order 13084, Consultation and Coordintion With 
Indian Tribal Governments
    H. Executive Order 13045, Protection of Children from 
Environmental Health Risks and Safety Risks
    I. National Technology Transfer and Advancement Act

I. Regulated Entities

    Entities potentially regulated by today's action are those that 
prepare sewage sludge and use or dispose of the sewage sludge through 
application to the land, placement on a surface disposal site, 
placement in a municipal solid waste landfill unit, or firing in a 
sewage sludge incinerator. Regulated categories and entities include:

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             Category                  Examples of regulated entities
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State/Local/Tribal Gov............  Publicly-owned treatment works that
                                     treat domestic sewage.
Federal Government................  Federally-owned treatment works that
                                     treat domestic sewage.
Industry..........................  Privately-owned treatment works that
                                     treat domestic sewage, and persons
                                     who receive sewage sludge and
                                     change the quality of the sewage
                                     sludge before it is used or
                                     disposed.
------------------------------------------------------------------------

    The above list of regulated categories and entities is not intended 
to be exhaustive, but rather provides a guide for readers regarding 
entities likely to be regulated by this action. The list includes the 
type of entities that EPA is now aware could potentially be regulated 
by this action. Other types of entities not listed above also could be 
regulated. To determine whether your facility is regulated by this 
action, you should carefully examine the applicability section in 
Sec. 503.1 (Purpose and Applicability) of part 503 of Title 40 of the 
Code of Federal Regulations. If you have questions regarding the 
applicability of this action to a particular entity, contact the 
individual whose name is in the preceding FOR FURTHER INFORMATION 
CONTACT section.

II. Authority

    The amendments to part 503 are promulgated pursuant to the 
authority of section 405 of the Clean Water Act (CWA), which requires 
EPA to establish numerical limits and management practices that protect 
public health and the environment from the reasonably anticipated 
adverse effects of toxic pollutants in sewage sludge. Section 405(e) 
prohibits any person from disposing of sewage sludge from a publicly 
owned treatment works (POTWs) or any other treatment works treating 
domestic sewage for any use or disposal for which regulations have been 
established pursuant to subsection (d) of section 405 except in 
compliance with such regulations.
    The amendment to part 403 is promulgated under the authority of 
sections 307 and 405 of the CWA. In section 307(b) of the CWA, Congress 
directed EPA to establish categorical pretreatment standards for 
industrial discharges of toxic pollutants to POTWs. Congress authorized 
POTWs in defined circumstances to provide relief from categorical 
pretreatment standards in the form of a removal credit to

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indirect dischargers. Section 307(b) authorizes a removal credit where, 
among other things, grant of the removal credit does not prevent the 
POTW from using or disposing of its sewage sludge in compliance with 
section 405 of the CWA.

III. Background

A. Part 503 Amendments

    On February 19, 1993, EPA promulgated, pursuant to section 405(d) 
of the CWA, Standards for the Use or Disposal of Sewage Sludge (58 FR 
9248). This regulation establishes the requirements that protect public 
health and the environment when sewage sludge is: (1) Applied to the 
land to either condition the soil or fertilize crops grown in the soil; 
(2) placed on a surface disposal site; (3) placed in a municipal solid 
waste landfill unit; or (4) fired in a sewage sludge incinerator. EPA 
amended the part 503 sewage sludge regulation on February 25, 1994 (59 
FR 9095) and again on October 25, 1995 (60 FR 54764) to address various 
issues.
    On October 25, 1995, EPA published a document in the Federal 
Register proposing several technical changes to part 503 (60 FR 54771). 
These changes were intended to address a number of issues identified 
since promulgation of the regulation. The proposed changes clarify 
certain requirements, provide additional flexibility to the regulated 
community in complying with the part 503 requirements, and modify the 
requirements for sewage sludge incinerators to make the requirements 
self-implementing. Comments on the October 1995 proposal were 
considered in developing the changes in today's final rule.

B. Part 403 Amendment

    Industrial facilities that discharge specific pollutants to POTWs 
for treatment must pretreat their effluent to meet categorical 
pretreatment standards promulgated under section 307(b) of the CWA. 
Section 307(b) also provides that where POTWs provide some or all of 
the treatment of an industrial user's wastewater required to meet a 
categorical pretreatment standard, POTWs may grant ``a removal credit'' 
to such an indirect discharger. The credit, in the form of a less 
stringent categorical pretreatment standard, allows an increased 
concentration of a pollutant in the discharge from the indirect 
discharger to the POTW.
    Section 307(b) of the CWA establishes three criteria that a POTW 
has to meet to obtain authority to grant a removal credit to a 
discharger of a toxic pollutant to the POTW: (1) The POTW removes all 
or any part of the toxic pollutant, (2) the POTW's ultimate discharge 
does not violate the effluent limitation or standard that would be 
applicable to the toxic pollutant if it were discharged directly rather 
than through a POTW, and (3) the discharge to the POTW does not prevent 
sewage sludge use or disposal by the POTW in accordance with section 
405 of the CWA. EPA promulgated removal credit regulations that are 
codified at 40 CFR 403.7.
    On February 19, 1993, EPA amended the part 403 General Pretreatment 
Regulations to add a new Appendix G that includes two lists of 
pollutants eligible for a removal credit with respect to the use or 
disposal of sewage sludge if the other procedural and substantive 
requirements of 40 CFR 403.7 are met. The first list (Appendix G--
Section I) includes, by sewage sludge use or disposal practice, the 
pollutants regulated in EPA's Standards for the Use or Disposal of 
Sewage Sludge (40 CFR part 503). The second list (Appendix G--Section 
II) includes, by sewage sludge use or disposal practice, additional 
pollutants eligible for a removal credit if the concentration of the 
pollutant in sewage sludge does not exceed the prescribed 
concentration. The pollutants in Appendix G--Section II are the 
pollutants EPA evaluated and decided not to regulate during the 
development of the part 503 regulation. See 58 FR 9381-9385, February 
19, 1993.
    The October 1995 proposal addressed the concentration for total 
chromium for land-applied sewage sludge on the list of pollutants in 
Appendix G--Section II of the part 403 regulations. EPA concluded after 
reviewing comments on the proposed concentration to establish the 
concentration at the value in today's final rule.

IV. Final Amendments to the Part 503 Land Application, Surface 
Disposal, Pathogen, and Vector Attraction Reduction Requirements

A. Ceiling Concentration Limits--Land Application

    In the October 25, 1995, document, EPA proposed to amend the 
applicability section of the land application requirements to clarify 
that the ceiling concentration limits (Table 1 of Sec. 503.13) apply to 
all sewage sludge that is land-applied. Specifically, EPA proposed to 
amend Sec. 503.10(b)(1), (c)(1), (d), (e), (f), and (g) to expressly 
provide that the ceiling concentration limits have to be met in all 
cases. All commenters on this proposed change concurred with the 
change. Thus, today's action amends Sec. 503.10(b)(1), (c)(1), (d), 
(e), (f), and (g) to require that the ceiling concentration limits in 
Table 1 of Sec. 503.13 be met.

B. Frequency of Monitoring

    Sections 503.16, 503.26, and 503.46 require periodic monitoring of 
sewage sludge for pollutants as well as periodic demonstration of 
compliance with certain pathogen density and vector attraction 
reduction requirements. The frequency of monitoring varies with the 
amount of sewage sludge used or disposed. The current regulation allows 
the permitting authority, after two years of monitoring, to reduce the 
frequency, but in no case may the permitting authority authorize 
monitoring less frequently than once a year. EPA proposed to amend the 
regulation to authorize the permitting authority to reduce the 
frequency of monitoring for pollutants and certain pathogen density 
requirements 1 to less than once a year.
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    \1\ For example, EPA proposed to authorize the permitting 
authority to reduce the frequency of monitoring for the pathogen 
densities in Sec. 503.32(a)(5)(ii) and Sec. 503.32(a)(5)(iii). The 
frequency of monitoring for all other pathogen densities (e.g., the 
1000 MPN per gram of total solids fecal coliform requirement for all 
Class A pathogen alternatives), and for the vector attraction 
reduction options (e.g., 38 percent volatile solids reduction) 
cannot be reduced by the permitting authority.
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    Several commenters opposed the proposed change because they 
believed it would undermine public confidence in the quality of sewage 
sludge that is used or disposed. They stated that consistent monitoring 
of sewage sludge is essential to retaining public support for the part 
503 regulation.
    The Agency does not agree that the proposed change to the frequency 
of monitoring requirements means that consistent monitoring of sewage 
sludge will not continue. The reduction in the frequency only applies 
to pollutant concentrations and certain pathogen density requirements, 
and only can be made by the permitting authority.
    EPA has decided to modify Sec. 503.16, Sec. 503.26, and Sec. 503.46 
to delete the requirement to monitor at least once per year. This 
change provides flexibility to permitting authority to tailor 
monitoring requirements to specific circumstances without jeopardizing 
public health and the environment.
    Today's change allows, but does not require, the permitting 
authority to reduce the frequency of monitoring. Moreover, the 
permitting authority's ability to reduce the monitoring frequency is 
limited to monitoring for pollutants and the enteric virus and viable 
helminth ova density requirements in pathogen Class A,

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Alternative 3 (see Sec. 503.32(a)(5)(ii) and (5)(iii)). This change 
does not apply to any other pathogen density requirement or to the 
vector attraction reduction requirements. Further, this change does not 
preclude the permitting authority from increasing the frequency of 
monitoring even if they reduce the frequency after two years of 
monitoring at the part 503 frequency.
    Thus, EPA is today amending Sec. 503.16(a)(2), Sec. 503.26(a)(2), 
and Sec. 503.46(a)(3) by deleting the phrase ``* * * but in no case 
shall the frequency of monitoring be less than once per year when * * 
*'' Note that the part 503 frequency of monitoring requirements do not 
apply if sewage sludge is not land-applied, surface-disposed, or fired 
in a sewage sludge incinerator during the year.

C. Certification Language

    Sections 503.17 and 503.27 of the current sewage sludge regulation 
require sewage sludge preparers and land appliers, and the owner/
operator of a surface disposal site, respectively, to keep certain 
records, and in the case of a Class I sludge management facility, to 
report this information to the permitting authority. The regulation 
also requires the recordkeepers to certify to compliance with 
applicable requirements. Failure to certify may result in significant 
penalties.
    The October 1995 notice proposed to change the certification 
language in the part 503 recordkeeping sections because the effect of 
requiring the appropriate person to certify compliance may be to 
discourage self-reporting of violations. If a requirement is not being 
met, the applicable person obviously cannot certify to compliance with 
the requirement without perjury. EPA proposed only to require that the 
applicable person certify to the accuracy of the information that was 
collected to show compliance. Compliance with the requirement then 
would be determined by the permitting authority.
    Commenters supported the proposed change. One commenter expressed 
concern, however, that the language change may be construed to relieve 
preparers of land-applied sewage sludge from meeting certain 
requirements. This is not the case. As indicated in Sec. 503.7, the 
preparer of land-applied sewage sludge is responsible to ensure that 
the applicable land application requirements are met. The change in the 
certification language does not relieve a preparer from this duty. 
Under the regulation, as amended, the appropriate person must certify 
that information collected to show compliance with a requirement was 
prepared under his/her direction and supervision in accordance with the 
system designed to ensure that qualified personnel gather and evaluate 
information properly.
    Another commenter suggested that the certifications in the land 
application recordkeeping section (Sec. 503.17) for the preparer be 
combined into one certification. The commenter also suggested this be 
done for the certifications for the applier. EPA has decided to retain 
the current certifications in the land application recordkeeping 
section without change because they contain the applicable 
certification for each requirement (i.e., pollutants, pathogens, and 
vector attraction reduction), and ensure there is no confusion about 
who is to certify to what.
    Today's action amends Sec. 503.17 by revising the certification 
language as described above in paragraphs (a)(1)(ii), (a)(2)(ii), 
(a)(3)(i)(B), (a)(3)(ii(A), (a)(4)(i)(B), (a)(4)(ii)(A), (a)(5)(i)(B), 
(a)(5)(ii)(F), (a)(5)(ii)(H), (a)(5)(ii)(J), (a)(5)(ii)(L), 
(a)(6)(iii), and (b)(6). EPA is also amending Sec. 503.27 by revising 
the certification language in paragraphs (a)(1)(ii), (a)(2)(ii), 
(b)(1)(i), and (b)(2)(i).

D. Time of Application

    In the October 25, 1995 Notice, EPA proposed to change certain of 
the recordkeeping requirements for land-applied sewage sludge and for 
domestic septage applied to agricultural land, forest, or a reclamation 
site. EPA proposed to delete the requirement in 
Sec. 503.17(a)(5)(ii)(C) and Sec. 503.17(b)(3) to record the time of 
application of bulk sewage sludge and domestic sewage, respectively, to 
a site. At the same time, EPA proposed to add a new requirement in 
Sec. 503.17(a)(4)(ii)(E) for Class B sewage sludge. This change would 
require appliers of Class B sewage sludge to record the date bulk 
sewage sludge is applied to each site. EPA concluded that, because the 
regulation restricts the use of sites to which Class B sewage sludge is 
applied,2 it is important to record the date Class B sewage 
sludge is land-applied. For the reasons discussed at proposal, EPA is 
today adopting these changes.
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    \2\ For example, Sec. 503.32(b)(5) prohibits the harvesting of 
food crops with harvested parts below the land surface up to 38 
months after land application of a Class B sewage sludge.
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E. Definition of pH

    EPA also proposed a change to the definition of pH to clarify that 
pH should be measured at 25 degrees Centigrade (C) or be converted to 
an equivalent value at 25 degrees C. Twenty-five degrees C is the 
reference temperature for reporting pH values in the scientific 
literature.
    Commenters favored the proposed change, which EPA is today adopting 
as proposed. Today's notice amends the definition of pH in 
Sec. 503.31(g) to read as follows: pH means the logarithm of the 
reciprocal of the hydrogen ion concentration measured at 25 deg. 
Centigrade or measured at another temperature and then converted to an 
equivalent value at 25 deg. Centigrade.
    The following equation from Smith and Farrell can be used to adjust 
pH values taken at temperatures other than 25 degrees C to equivalent 
values at 25 degrees C:

pH correction = [0.03 pH units/1.0 deg. C]  x  [Temp deg. 
Cmeas -25 deg. C]

This equation indicates that for each degree difference between the 
measured temperature in degrees C and 25 degrees C, there is a change 
in pH of 0.03 units. Thus, if a pH of 12 is measured at 20 degrees C, 
the pH at 25 degrees C is 11.85 [12 + (0.03  x  -5)]. There is an 
inverse relationship between temperature and pH.

F. Class B, Alternative 1--at the Time of Use or Disposal

    EPA also proposed to amend Sec. 503.32(b)(2) to change the pathogen 
reduction requirements in pathogen Class B, Alternative 1 to allow 
those requirements to be met any time before the sewage sludge is used 
or disposed. Under the current regulation, these requirements must be 
met ``at the time the sewage sludge is used or disposed.''
    There were two reasons for EPA's decision to propose this change. 
First, the requirement in Sec. 503.32(b)(2) is inconsistent with the 
requirements in the two other Class B pathogen 
alternatives.3 Part 503 does not require that the 
requirements in either Class B, Alternative 2 or Class B, Alternative 3 
be met at the time the sewage sludge is used or disposed. For example, 
when the requirements in Class B, Alternative 2 are met, the sewage 
sludge can be stored and then land-applied. Part 503 does not require 
additional treatment after the storage period.
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    \3\ These alternatives are Class B, Alternative 2 (treat sewage 
sludge in a Process to Significantly Reduce Pathogens (PSRP)) and 
Class B, Alternative 3 (treat sewage sludge in a process that is 
equivalent to a PSRP). See Sec. 503.32(b)(3) and Sec. 503.32(b)(4).
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    Second, EPA concluded that protection of public health and the 
environment does not require that the Class B pathogen requirements be 
met at the time sewage sludge is used or disposed. The part 503 rule 
imposes site restrictions for Class B sewage sludge that is land-
applied and management

[[Page 42555]]

practices for surface-disposed Class B sewage sludge irrespective of 
which Class B pathogen alternative is selected. The site restrictions 
and management practices allow time for the environment to further 
reduce remaining pathogens in the sewage sludge to below detectable 
levels.
    To make the Class B pathogen alternatives consistent, the Agency 
proposed to delete the requirement that the fecal coliform density in 
Class B, Alternative 1 be met at the time of use or disposal. This 
means that the fecal coliform density requirement can be met any time 
(e.g., before storage) before the sewage sludge is used or disposed. As 
mentioned above, the site restrictions for land-applied Class B sewage 
sludge and the surface disposal management practices provide time for 
the environment to further reduce the remaining pathogens in Class B 
sewage sludge to below detectable levels.
    One commenter opposed the proposed change believing that it would 
increase the public health risk, particularly when the sewage sludge is 
stored before it is used or disposed. The Agency disagrees and is 
adopting the change as proposed.
    There is no evidence of increased incidences of disease from 
exposure to Class B sewage sludge that is either stored, or used or 
disposed. There is evidence, however, that over time the densities of 
Salmonella sp. bacteria, enteric viruses, and viable helminth ova in 
sewage sludge are reduced to below detectable levels by environmental 
conditions. Thus, in EPA's judgement, public health and the environment 
are protected when the Class B pathogen requirements and the land 
application site restrictions for a Class B sewage sludge are met. With 
respect to the concern about stored sewage sludge, the U.S. Department 
of Agriculture and EPA are preparing guidance on storage of sewage 
sludge. This guidance will address, among other things, good practices 
for storing sewage sludge. Today's action amends Sec. 503.32(b)(2)(i) 
to indicate that seven representative samples of the sewage sludge that 
is used or disposed shall be collected.

G. Site Restriction for Grazing of Animals

    EPA also proposed to change the site restriction in 
Sec. 503.32(b)(5)(v). The current regulation indicates that animals 
shall not be allowed to graze for 30 days after land application of a 
Class B sewage sludge. The language in the proposed change indicates 
that animals shall not be grazed for 30 days after land application of 
a Class B sewage sludge. This restriction applies to the intentional, 
not inadvertent, grazing of animals. Commenters supported this change, 
and EPA is adopting it today.

H. Vector Attraction Reduction Equivalency

    Sewage sludge has a number of qualities that may attract disease-
spreading agents--``vectors''--like birds, flies and rats. The part 503 
regulation includes requirements for reducing what is called ``vector 
attraction'' potential. The regulation allows use of any of 10 vector 
attraction reduction options when sewage sludge is applied to the land 
(or 11 options in the case of sewage sludge that is placed on a surface 
disposal site). See 40 CFR 503.33.
    In the October 25, 1995, notice, EPA proposed to allow the use of 
other vector attraction reduction options for any of the eight 
treatment options if the permitting authority determined that such an 
option was ``equivalent,'' (i.e, equally effective in reducing vector 
attraction). This flexible approach is similar to that provided 
currently in the part 503 regulation for Class A and Class B pathogen 
reduction processes. Processes other than those prescribed in the 
regulation may be used to reduce pathogens if the permitting authority 
determines they are equivalent.
    All of the commenters supported the proposed change. However, none 
of the commenters provided information necessary to develop appropriate 
measures that could be used to determine whether an option is 
equivalent to one of the first eight vector attraction reduction 
options. Without such measures, equivalency cannot be determined.
    Because no measures exist currently that can be used to determine 
whether a vector attraction reduction option is equivalent to one of 
the first eight vector attraction reduction options, EPA concluded that 
the part 503 regulation should not be amended at this time to allow for 
vector attraction reduction equivalency. For this reason, today's 
action does not amend Sec. 503.15(c), Sec. 503.25(b), and 
Sec. 503.33(a).
    The Agency encourages anyone with information that can be used to 
develop appropriate measures for vector attraction reduction 
equivalency to submit the information to EPA. If measures can be 
developed, EPA will consider reproposing the changes to Sec. 503.15(c), 
Sec. 503.25(b), and Sec. 503.33(a) to allow an option that is 
equivalent to one of the first eight vector attraction reduction 
options, if the equivalent option is approved by the permitting 
authority.

I. Vector Attraction Reduction at the Time of Use or Disposal

    Another proposed change in the October 25th notice was the time 
when certain vector attraction reduction options have to be met. Under 
the current regulation, vector attraction reduction Options 1 through 8 
can be met any time before the sewage sludge is used or disposed. In 
the case of Options 9, 10, and 11, however, they must be met at the 
time the sewage sludge is used or disposed.
    The October 25th notice proposed to change the time when vector 
attraction reduction Options 6, 7, and 8 have to be met. The proposed 
change required that those options be met at the time the sewage sludge 
is used or disposed rather than any time before the sewage sludge is 
used or disposed.
    As explained in the proposal (60 FR 54775, October 25, 1995), 
vector attraction reduction achieved by pH adjustment (Option 6) may 
not always be permanent. The target pH conditions in Option 6 allow 
sewage sludge to be stored for some period before use or disposal 
without the pH dropping. If the sewage sludge is stored for some longer 
period of time, however, the pH may drop. At that point, biological 
activity in the sewage sludge may resume, and the sewage sludge may 
putrefy and attract vectors.
    Similarly, in the case of vector attraction reduction Options 7 and 
8, the moisture content of the sewage sludge may increase during 
storage after the percent solids requirements are met, and biological 
activity could increase. This also could cause vectors to be attracted 
to the sewage sludge.
    EPA received a significant number of comments opposing the proposed 
change for Option 6--pH adjustment. Several commenters stated that the 
proposed change to Option 6 would require them to adjust the pH of the 
sewage sludge twice--once before storage and then again after storage 
before use or disposal. This would increase the cost of Option 6.
    The commenters assumed incorrectly that part 503 requires the pH of 
the sewage sludge to be adjusted prior to storage. EPA only proposed to 
require that the pH be adjusted at the time of use or disposal. Thus, 
the only cost attributable to part 503 would be the cost of one pH 
adjustment at the time of use or disposal.
    The commenters presented several other reasons for retaining Option 
6 in its current form. These include the following. First, nutrient 
problems could result when high pH sewage sludge is land-applied (micro 
nutrients

[[Page 42556]]

are less available for plant uptake in high pH soils, particularly in 
coastal plains). Second, the high calcium content of the sewage sludge 
will lower the agronomic rate for the application site. Third, the 
effectiveness of herbicides applied to a site will be reduced because 
herbicides are less available in high pH soils. Finally, sewage sludge 
with a high pH may induce manganese deficiency because manganese is 
more water soluble at high pH and, thus, may be removed from a site 
through leaching to ground water. Some commenters also indicated that 
if Option 6 is changed, ``unstabilized'' sewage sludge could be 
stockpiled or stored and could cause harm to public health. Other 
commenters indicated there have been no vector attraction problems in 
cases where the pH of the sewage sludge is adjusted prior to storage, 
but not at the time of use or disposal.
    The only comment on the proposed change to Options 7 and 8 (i.e., 
percent solids) suggest that these options are often relied on by small 
POTWs. Thus, the change may have an economic impact on those POTWs.
    After further review, EPA concluded that the time when vector 
attraction reduction Options 6, 7, and 8 have to be met should not be 
changed. In cases where Option 6 is met prior to storage of the sewage 
sludge, the pH of the sewage sludge could drop during storage. The 
Agency agrees, however, that there have been no documented cases of 
vector attraction problems when this occurs, and that it is desirable 
to reduce the attractiveness of stored sewage sludge to vectors. In 
addition, there are measures that can be taken to keep the pH of the 
sewage sludge from dropping during storage. Thus, the time when Option 
6 can be met (i.e., any time before the sewage sludge is used or 
disposed) remains unchanged.
    In the case of Options 7 and 8, the Agency is not aware of any 
documented cases concerning protection of public health and the 
environment when those options are met prior to use or disposal. Thus, 
the time when Options 7 and 8 can be met (i.e., any time before the 
sewage sludge is used or disposed) also remains unchanged.

J. Time Period for Vector Attraction Reduction Option 10

    In the October 25, 1995, notice, EPA proposed to modify the part 
503 regulation to allow the permitting authority to change the time 
period sewage sludge has to be incorporated into the soil in vector 
attraction reduction Option 10. Vector attraction reduction Option 10 
requires incorporation of sewage sludge into the soil within six hours 
after it is land-applied or surface-disposed. This reduces the 
attraction of vectors to the sewage sludge by placing a barrier between 
the sewage sludge and the vectors. EPA proposed this change to allow 
the permitting authority to consider site-specific conditions (e.g., 
the remoteness of the land application site) that may affect the time 
period during which sewage sludge can be incorporated into the soil.
    Commenters supported the proposed change. However, one commenter 
asked EPA to modify the language so as to make it clear that, while the 
permitting authority may relax the time requirements in Option 10, the 
permitting authority could not tighten them. EPA is rejecting this 
suggestion because there may be circumstances in which more rapid soil 
incorporation is necessary to protect public health and the 
environment.
    The current regulation authorizes the permitting authority to 
modify the existing part 503 requirements where warranted by 
circumstances. Section 503.5(a) indicates that a permitting authority 
may impose additional or more stringent requirements than the 
requirements in part 503 if necessary to protect public health and the 
environment. Section 503.5(b) indicates that a State or political 
subdivision thereof can establish additional or more stringent 
requirements than those in part 503 for any reason.
    EPA is today amending Sec. 503.33(b)(10)(i) to allow the permitting 
authority to increase the time period during which sewage sludge has to 
be incorporated into the soil. Only the permitting authority can 
authorize a time period that is different from the time period in part 
503.

K. Technical Corrections

    In the October 25, 1995 Notice, EPA proposed several technical 
corrections to part 503 that were minor in nature and that clarified 
some of the technical requirements of the part 503 regulation. 
Commenters supported the clarifications. Today's final amendment makes 
the following technical corrections to the part 503 regulation with the 
one exception discussed below.

1. Sections 503.16(a)(1) and 503.26(a)(1)--Frequency of Monitoring

    Sections 503.16(a)(1) and 503.26(a)(1) contain the requirements for 
monitoring for pollutants, pathogen densities, and vector attraction 
reduction. Those sections indicate there are pathogen density 
requirements in Sec. 503.32(b)(3) and (b)(4). This is incorrect. 
Today's final amendment deletes the reference to Sec. 503.32(b)(3) and 
(b)(4) from Sec. 503.16(a)(1) and Sec. 503.26(a)(1).
    Sections 503.16(a)(1) and 503.26(a)(1) also indicate that the 
frequency of monitoring requirements apply to vector attraction 
reduction Option 5 in Sec. 503.33(b)(5) and Option 6 in 
Sec. 503.33(b)(6). This also is incorrect. Today's final amendment 
deletes the reference to vector attraction reduction Options 5 and 6 
from Sec. 503.16(a)(1) and Sec. 503.26(a)(1).

2. Section 503.17(b)(7)--Recordkeeping for Land Application of Domestic 
Septage

    Today's final amendment changes Sec. 503.17(b)(7) by changing an 
incorrect reference.

3. Section 503.18--Reporting

    Today's final amendment corrects the omission of a reporting date 
in the part 503 regulation by inserting February 19th in 
Sec. 503.18(a)(2).

4. Section 503.21(c)--Contaminate An Aquifer

    Today's final amendment corrects the reference to the maximum 
contaminant level for nitrate in Sec. 503.21(c). On January 30, 1991, 
EPA published a regulation (56 FR 3526) that changed the reference for 
the maximum contaminant level for nitrate from 40 CFR 141.11 to 40 CFR 
141.62(b). That change was effective July 30, 1992. For this reason, 
the reference to the maximum contaminant level for nitrate in the 
definition of contaminate an aquifer is being changed to 40 CFR 
141.62(b) in today's final rule.

5. Section 503.22(b)--General Requirements

    Today's final amendment changes Sec. 503.22(b) by correcting the 
statutory reference and by inserting the appropriate date.

6. Section 503.32(a)(3)--Pathogens

    In the October 1995 notice, EPA indicated that pathogen Class A, 
Alternative 1 only applies to thermal processes such as anaerobic 
digestion, and does not apply to composting. Upon further review, EPA 
concluded that the time/temperature conditions in Class A, Alternative 
1 can be achieved through composting. If the temperature of every 
particle of the composted sewage sludge is raised to the appropriate 
value for the appropriate time period, Salmonella sp. bacteria, enteric 
viruses, and viable helminth ova in the sewage sludge are reduced to 
below detectable levels. For this reason, the proposed change to

[[Page 42557]]

Sec. 503.32(a)(3) to exclude composting is not being made.

7. Appendix B to Part 503--Pathogen Treatment Processes

    The description of Process to Further Reduce Pathogens (PFRP) No. 6 
(Gamma ray irradiation) is corrected to insert the phrase ``at dosages 
of at least 1.0 megarad at room temperature (ca. 20 deg. C)'' that was 
omitted inadvertently.

V. Final Amendments to the Part 503 Incineration Requirements

A. Compliance Period

    In the October 25, 1995, proposal, EPA proposed to amend Sec. 503.2 
to require compliance with the revised incineration requirements in 
subpart E of part 503 as expeditiously as practicable, but in no case 
later than 90 days after publication of the final amendment. If 
compliance with the revised subpart E requirements required 
construction of new pollution control facilities compliance had to be 
achieved as expeditiously as practicable but no later than 12 months 
after publication of today's final amendment.
    Commenters indicated that 90 days are not enough to comply with the 
revised incineration requirements, particularly the requirement to 
install continuous emission monitors for total hydrocarbons (THC). EPA 
agrees, and has increased the time to comply with the revised 
requirements in subpart E.
    Today's final rule amends Sec. 503.2 by adding a new paragraph (d) 
that, unless otherwise specified in subpart E, requires compliance with 
the revised subpart E requirements in the final rule as expeditiously 
as practicable, but in no case later than 12 months after the effective 
date for the final rule. If new pollution control facilities have to be 
constructed to comply with the revised requirements, compliance with 
the revised subpart E requirements shall be achieved as expeditiously 
as practicable, but no later than 24 months after the effective date 
for the final rule.

B. Site-Specific Exemption From Frequency of Monitoring, Recordkeeping, 
and Reporting Requirements

    The October 25, 1996, notice proposed to amend the applicability 
section in Sec. 503.40 to exempt sewage sludge incinerators on a site-
specific basis from the frequency of monitoring, recordkeeping, and 
reporting requirements for a specific pollutant in defined 
circumstances. Under the proposed approach, if the limit for arsenic, 
cadmium, chromium, lead or nickel, determined pursuant to Sec. 503.43, 
is significantly higher than the measured concentration for the 
pollutant, the permitting authority could exempt the pollutant from the 
above requirements so long as the incinerator continued to operate 
within the values for the incinerator operating parameters established 
during the performance test required by the regulation. The notice 
requested comments on whether this approach is appropriate, and how to 
determine whether the calculated limit for a pollutant is significantly 
higher than the measured concentration of the pollutant in sewage 
sludge.
    All commenters favored allowing such an exemption. With respect to 
how to determine whether a calculated pollutant limit is significantly 
higher than the measured concentration, commenters suggested two 
different approaches. The first limits the availability of the 
exemption for a pollutant to circumstances in which the monthly average 
pollutant concentration did not exceed 50 percent of the calculated 
limit. The second approach varies the frequency of monitoring, based on 
the percentage the measured concentration bore to the calculated limit. 
For example, the frequency of monitoring could be reduced to once per 
year if the measured concentration is 80 percent of the calculated 
limit. If the measured concentration is 60 percent of the calculated 
limit or less, there would be no monitoring requirement for that 
pollutant.
    After considering this proposed change further, EPA has decided not 
to amend the regulation for the following reasons. Although several 
commenters offered suggestions on how to determine whether a calculated 
limit is significantly higher than the measured concentration for a 
pollutant, no commenter provided any test the permit writer could apply 
for ensuring that, in fact, the actual concentration for the pollutant 
falls substantially below the calculated limit. Moreover, there are 
questions about how much data are needed to support an exemption and 
the period of the exemption (e.g., one year, five years, or forever). 
In addition, there are many factors that could affect the actual 
concentration of a pollutant in sewage sludge (e.g., variability of the 
pollutant in the influent to the treatment works).
    Another concern EPA has about the proposed change is the assumption 
that the incinerator will be operated as it was during the performance 
test. There are many factors that affect the performance test results 
(e.g., feed rate and excess oxygen). If these factors change, the 
calculated limits for a pollutant could change.
    Given the concerns about changes in both the calculated limit and 
the measured concentration of a pollutant in sewage sludge, EPA 
concluded that the part 503 regulation should not provide for a site-
specific exemption from the frequency of monitoring, recordkeeping, and 
reporting requirements in subpart E. Thus, today's notice does not 
amend Sec. 503.40 to add a new paragraph (d).

C. Pollutant Limits for Arsenic, Cadmium, Chromium, Lead and Nickel

    In the October 25, 1995 notice, EPA proposed several changes to the 
requirements in Sec. 503.43 for sewage sludge that is incinerated. As 
explained in greater detail in the preamble to the proposal (60 FR 
54777-54779, October 25, 1995), 40 CFR 503.43 establishes limits on the 
allowable ``daily concentration'' of arsenic, cadmium, chromium, lead 
and nickel in sewage sludge. The allowable limits are calculated using 
equations set forth in the regulation, and are dependent on a number of 
factors that vary with specific conditions at an incinerator site. To 
calculate the limit for each of the five pollutants, the regulation 
requires determination of two factors that are dependent on site-
specific conditions. They are: (1) A dispersion factor (DF)--how 
pollutants are dispersed when they exit the incinerator stack, and (2) 
the incinerator's control efficiency (CE)--how efficiently the 
incinerator removes a pollutant in the sewage sludge that is 
incinerated. The regulation requires use of an air dispersion model to 
determine the DF and a performance test to establish the CE, both of 
which must be specified by the permitting authority. In addition, in 
the case of chromium, the regulation requires the permitting authority 
to determine whether the risk specific concentration (RSC) for 
chromium, which is used to establish the allowable chromium sewage 
sludge pollutant concentration, should be based on default values 
provided in the regulation (Table 2 of Sec. 503.43) or determined by a 
site-specific calculation.
    The requirement for site-specific action by the permitting 
authority has significant implications for compliance and enforcement 
of the regulation. Site-by-site tailoring of a particular incinerator's 
requirements effectively defers the determination of an individual 
incinerator's limits until action by the permitting authority. Given 
the resource-intensive nature of these site-by-site determinations and 
constraints on available resources, EPA

[[Page 42558]]

proposed to adopt a different approach. The Agency proposed to delete 
the requirement for the permitting authority to approve the air 
dispersion modeling and performance tests used to determine DF and CE, 
respectively, as well as modify the requirement for the permitting 
authority to determine the appropriate chromium RSC. EPA also proposed 
to clarify the definition of the allowable concentration of a pollutant 
in sewage sludge.
1. Average Daily Concentration
    EPA proposed to revise 40 CFR 503.43(c)(1) and (d)(1) to clarify 
that the calculated sewage sludge concentration is an average daily 
concentration based on the number of days in a month that the 
incinerator operates. This change made the calculated concentration 
consistent with the risk specific concentration (i.e., the allowable 
ambient air concentration for a pollutant developed through risk 
assessment) for a pollutant.
    Comments on this proposed changed were generally favorable, but the 
commenters asked for a clarification with respect to the number of days 
in the month the incinerator operates. Commenters questioned whether 
the calculated limit was a monthly average. Upon further review, EPA 
concluded that it is not appropriate to calculate the allowable 
concentration of a pollutant in sewage sludge fed to a sewage sludge 
incinerator using the number of days in the month the incinerator 
operates. Instead, the average daily concentration should be the 
arithmetic mean of the concentration of a pollutant in the samples 
collected and analyzed during a month. Thus, if one sample is collected 
and analyzed during the month, the average daily concentration is the 
concentration of a pollutant in that sample. If two samples are 
collected and analyzed during the month, the average daily 
concentration is the arithmetic mean of the concentration of a 
pollutant in those two samples. Likewise, if only one sample is 
collected and analyzed during the year, the average daily concentration 
is the concentration for a pollutant in that one sample.
    After considering the comments on the proposed change to the 
allowable concentration of a pollutant in sewage sludge, EPA concluded 
that the allowable concentration should be an average daily 
concentration. Thus, today's notice amends Sec. 503.43(c)(1) and (d)(1) 
by changing the definition of ``C'' in equations (4) and (5), 
respectively, to average daily concentration. Today's notice also 
amends Sec. 503.41--Special Definition--by adding the following 
definition for average daily concentration: ``Average daily 
concentration is the arithmetic mean of the concentration of a 
pollutant in milligrams per kilogram of sewage sludge (dry weight 
basis) in the samples collected and analyzed in a month.''
2. Approval of Air Dispersion Model and Performance Test
    As noted above, the October 1995 notice proposed to amend the 
regulation to delete the requirement in Sec. 503.43(c)(2), (c)(3), 
(d)(4), and (d)(5) for the permitting authority to specify the air 
dispersion model and performance test used to calculate the sewage 
sludge pollutant limits. EPA received no comments on these proposed 
changes. Therefore, today's notice amends Sec. 503.43 (c)(2), (c)(3), 
(d)(4), and (d)(5) by deleting the requirement for the permitting 
authority to specify how to meet these requirements.
    EPA also proposed amending Sec. 503.43(d)(3) to delete the 
requirement for the permitting authority to specify one of the two 
means of calculating the risk specific concentration for chromium. EPA 
received only one comment, and it favored the proposed change. Thus, 
today's final rule amends Sec. 503.43(d)(3) by deleting the requirement 
for the permitting authority to specify how to meet this requirement.
    The October 1995 notice also proposed to add a new paragraph (e) to 
Sec. 503.43. This paragraph contains requirements for air dispersion 
modeling and performance tests to serve the purpose of the deleted 
requirements in Sec. 503.43(c)(2), (c)(3), (d)(4), and (d)(5) that the 
permitting authority specify the air dispersion model and performance 
test.
    The proposed Sec. 503.43(e)(1) required that any air dispersion 
model and performance test be ``consistent with good air pollution 
control practices for minimizing air pollution.'' One commenter 
objected to this provision asserting that such a requirement was 
inappropriate. In the commenter's view, an air dispersion model and a 
performance test are used to measure something, not to minimize air 
emissions. EPA concurs with the comment on Sec. 503.43(e)(1). Thus, 
today's final amendment only requires that the air dispersion model be 
appropriate for the geographical, physical, and population 
characteristics at the incinerator site, and that the performance test 
be appropriate for the type of sewage sludge incinerator.
    Proposed Sec. 503.43(e)(2) required that an air dispersion modeling 
protocol be submitted to the permitting authority within 30 days of the 
publication date of this final amendment. The permitting authority 
would then have 30 days to review the protocol, including the selected 
air dispersion model, and provide comments on the protocol. If the 
permitting authority did not object within 30 days, the protocol could 
be used to determine the dispersion factor for the incinerator site. No 
comments were received on this proposed requirement.
    Upon further review, EPA concluded that the air dispersion model 
protocol should not be submitted to the permitting authority 30 days 
from the date of publication of this final amendment because the Agency 
lacks the resources to review and comment on the protocol within 30 
days after it is received. Instead, today's action amends 
Sec. 503.43(e)(2) to require that results of air dispersion modeling 
initiated after September 3, 1999, be submitted to the permitting 
authority no later than 30 days after completion of the modeling. This 
requirement does not apply to air dispersion modeling completed prior 
to September 3, 1999.
    EPA encourages the person who conducts the air dispersion modeling 
to coordinate with the permitting authority prior to conducting the 
modeling. This could prevent future problems if the permitting 
authority has concerns about the air dispersion modeling.
    As indicated in the October 1995 notice, EPA has published several 
guidance documents that contain recommendations on how to select 
appropriate air dispersion models. These models consider such site-
specific factors as stack height, stack diameter, stack gas 
temperature, exit velocity and topography of surrounding terrain. See 
Guidelines on Air Quality Models in Appendix W to 40 CFR part 51 and in 
the U.S. EPA, ``Technical Support Document for Sewage Sludge 
Incineration'' at Section 5.6.1 (EPA 822/R-93-003, November 1992). 
Information on air quality models also can be obtained from the Support 
Center for Regulatory Air Models (SCRAM) on the Technology Transfer 
Network, (http://ttnwww.rtpnc.epa.gov/).
    Proposed Sec. 503.43(e)(3) contained the minimum procedures for 
conducting a performance test. A performance test measures the degree 
to which a sewage sludge incinerator and associated air pollution 
control devices remove a pollutant. As previously explained, the 
pollutant control efficiency from a performance test is used to 
calculate the allowable concentration of a pollutant in sewage sludge 
fired in the incinerator.

[[Page 42559]]

    The procedures in the proposed Sec. 503.43(e)(3) parallel the 
procedures in 40 CFR 60.8, a regulation that describes the general 
procedures for conducting performance testing under the Clean Air Act. 
EPA concluded that it is necessary to specify minimum procedures for 
conducting performance tests now that the part 503 incineration 
requirements are self-implementing.
    The procedures in proposed Sec. 503.43(e)(3)(i) require that the 
performance test be conducted under representative incinerator 
conditions at the highest expected sewage sludge feed rate within 
design specifications. A commenter suggested that EPA should recognize 
the variability in the feed rate during the operation of the sewage 
sludge incinerator.
    EPA agrees that the feed rate used in performance tests may well 
differ from the sewage sludge feed rate during day-to-day operation of 
the incinerator. Part 503 takes this into account by requiring that the 
``highest expected'' feed rate be used in the performance test. Because 
the actual feed rate is expected to be equal to or less than the 
highest expected feed rate, the actual feed rate should not cause the 
control efficiency for a pollutant to decrease during the day-to-day 
operation of the incinerator.
    The above comment is more applicable to the feed rate used to 
calculate the limit for a pollutant than to the feed rate during a 
performance test. As provided in the current rule, the sewage sludge 
feed rate used in the equations in Sec. 503.43(c)(1) and (d)(1) to 
calculate the limit for a pollutant takes the feed rate during 
operation into account. The feed rate used in these equations is either 
the average daily amount of sewage sludge fired in all sewage sludge 
incinerators within the property line of the site where the sewage 
sludge incinerators are located for the number of days in a 365 day 
period that each sewage sludge incinerator operates, or the average 
daily design capacity for all sewage sludge incinerators within the 
property line of the site where the sewage sludge incinerators are 
located (see Sec. 503.41(j)). This definition recognizes potential 
variability in the actual feed rate, and accounts for the variability 
by providing for averaging over a 365 day period.
    The October 25, 1995, proposal required in Sec. 503.43(e)(3)(ii) 
that the permitting authority be notified at least 30 days prior to a 
performance test so that the permitting authority may have the 
opportunity to comment on the test protocol and test methods, and to 
observe the test. This requirement does not apply in cases where 
performance tests were conducted prior to September 3, 1999. This 
change is included in today's final rule as proposed.
    EPA has decided not to adopt a provision it proposed as 
Sec. 503.43(e)(3)(iii) that would have required that performance 
testing facilities contain safe sampling platforms and safe access to 
them because that provision is not related directly to the use or 
disposal of sewage sludge. In addition, for sewage sludge incinerators 
subject to 40 CFR part 60, subpart O, the proposed provision reflects a 
similar provision in 40 CFR 60.8 concerning performance tests. There 
also may be other federal or state safety requirements that govern the 
way performance tests are conducted. Therefore, the Agency concluded 
that this provision does not need to be in today's final rule.
    Today's final Sec. 503.43(e)(3)(iii), proposed as subparagraph 
(e)(3)(iv), concerns the number of runs for a performance test. Each 
performance test shall consist of three runs. The arithmetic mean of 
the results of the three runs is the control efficiency for a 
pollutant. All commenters on this proposal agreed with the requirement. 
Thus, this requirement in today's final rule is the same as it was in 
the proposal.
    Today's action also promulgates Sec. 503.43(e)(4) as proposed on 
October 25, 1995. This provision requires that the calculated pollutant 
limits be submitted to the permitting authority within 30 days of 
completion of air dispersion modeling and performance tests.
    As proposed, Sec. 503.43(e)(5) requires new air dispersion modeling 
and performance testing when there are ``significant changes'' in 
specific aspects of the site or in incinerator operating conditions. 
One commenter asked how high above the feed rate in the performance 
tests or the feed rate used to calculate pollutant limits can the 
actual feed rate be before a new performance test or a new limit for a 
pollutant is required. One possibility is to allow the actual feed rate 
to increase by a certain percentage (e.g., 10 percent) of the feed rate 
in the performance test or the feed rate used to calculate a limit 
before a new performance test has to be conducted or a new limit for a 
pollutant calculated.
    Another possibility is to decide how much the actual feed rate can 
increase on a case-by-case basis. Under this approach, all the factors 
that affect the decision on whether to conduct a new performance test 
or calculate a new limit can be considered. For example, if the 
measured concentration of a pollutant in sewage sludge is significantly 
lower than the calculated limit for the pollutant, public health may 
still be protected if the feed rate increases by more than 10 percent, 
while in another case, an increase of 10 percent in the feed rate may 
result in a pollutant limit being exceeded.
    Today's final rule does not specify when new performance tests have 
to be conducted or when new pollutant limits have to be calculated. 
Section 503.43(e)(5) indicates that significant changes in incinerator 
operating conditions will require that new performance tests be 
conducted. The decision on whether a change in operating conditions, 
including feed rate, is significant will be determined on a case-by-
case basis by the permitting authority. Protection of public health 
should be the major factor in deciding whether to conduct new 
performance tests or calculate new pollutant limits.
3. Technical Corrections
    The October 1995 notice also proposed three technical corrections 
to Sec. 503.43(d)(1) and (d)(2). Two of the changes corrected 
typographical errors in the definition of terms in (d)(1) and the other 
change corrected a reference in (d)(2). These changes are included in 
today's final rule.
4. Air Emissions Analytical Methods
    The preamble in the October 1995 notice requested comments on 
whether to specify methods to analyze emissions from sewage sludge 
incinerator stacks in part 503. Commenters on the proposal recommended 
that EPA not include specific test methods for air emissions in part 
503 because EPA approved methods already are required in other 
regulations. EPA agrees with the commenters.
    EPA's Office of Air Quality Planning and Standards has approved 
Method 29 in 40 CFR part 60, Appendix A as a method for determining 
compliance with the particulate emissions standards in subpart O of 40 
CFR part 60 (Standards of Performance for Sewage Treatment Plants), and 
the beryllium and mercury emissions standards in subparts C and E, 
respectively, of 40 CFR part 61 (National Emission Standards for 
Hazardous Air Pollutants). This method only requires that one sampling 
train be used. The methods in 40 CFR part 266 (Boilers and Industrial 
Furnaces), Appendix IX, section 3.1 also can be used to measure 
emission rates. When those methods are used, more than one sampling 
train is needed. Because both methods are available, today's final rule 
does not specify a method to measure emission rates. EPA recommends, 
however, that Method 29

[[Page 42560]]

be used during the performance test required by part 503 because that 
method only requires one sampling train.

D. Management Practices

    Sections 503.45(a)(1) and Sec. 503.45(b)-(d) of the sewage sludge 
regulation require the installation of instruments that continuously 
monitor total hydrocarbons (THC) concentration, oxygen concentration, 
information to determine moisture content in the sewage sludge 
incinerator stack emissions, and combustion temperature, respectively. 
These instruments must be installed, calibrated, operated, and 
maintained ``as specified by the permitting authority.''
    As explained in the October 1995 proposal (60 FR 54779), the part 
503 regulation required the permitting authority to specify the manner 
in which the above instruments are installed calibrated, operated, and 
maintained because, at the time the regulation was published, there was 
only limited EPA guidance in this area. Because there is now EPA 
guidance on how to install, calibrate, operate, and maintain the above 
instruments, EPA proposed to amend Sec. 503.45(a)(1) and 
Sec. 503.45(b)-(d) to delete the requirement that the permitting 
authority specify how the instruments required by those sections are 
installed, calibrated, operated, and maintained. With one exception, 
all comments received on the proposed changes concurred with the 
changes.
    EPA received one comment suggesting alternative means of 
demonstrating compliance with the total hydrocarbons or carbon monoxide 
operational standards. The commenter suggested that EPA consider 
providing for the site-specific establishment and continuous monitoring 
of a minimum incinerator exhaust temperature, in lieu of continuous 
monitoring of total hydrocarbons or carbon monoxide. The commenter also 
suggested that the incinerator owner/operator be allowed to demonstrate 
a site-specific correlation between total hydrocarbons and carbon 
monoxide emissions as an alternative method of demonstrating compliance 
with either emissions limit. The Agency did not propose either of these 
alternatives in the October 25, 1995 proposal. However, in the preamble 
to the proposal, the Agency stated that it would study monitoring for 
other parameters, including temperature, to measure compliance with 
either the total hydrocarbon limit or the carbon monoxide limit and 
would decide whether further amendments to part 503 were needed as a 
result of the study. (60 FR 54779). EPA undertook this study and 
produced a report on the feasibility of alternatives to continuous 
monitoring of total hydrocarbons or carbon monoxide. A copy of the 
report, entitled ``An Investigation of Alternative Means for 
Demonstrating Compliance with the part 503 Total Hydrocarbon 
Operational Standards,'' EPA 822-R-98-001 is in the rulemaking docket. 
The study indicated that, while technically feasible on a site-specific 
basis , either of these options would be extremely resource intensive 
and would involve the permitting authority in complex procedures to 
determine and approve site-specific temperature limits or site-specific 
total hydrocarbons/carbon monoxide correlations. As a result of these 
findings, the Agency, has decided not to pursue either the option of 
establishing and continuously monitoring for site-specific temperature 
limits or the option of establishing site-specific correlations between 
total hydrocarbons and carbon monoxide emissions in lieu of complying 
independently with either the 100 ppm total hydrocarbons or carbon 
monoxide emissions limits. However, the Agency invites the public to 
comment on whether these options for demonstrating compliance should be 
pursued further and to provide any additional information to supplement 
the report that EPA relied on in deciding not to allow for these 
alternatives at this time. Thus, the above changes are included in 
today's final rule.
    In the October 1995 notice, EPA also proposed to delete the 
requirements in Sec. 503.45 (e) and (f) for the permitting authority to 
specify the maximum combustion temperature for a sewage sludge 
incinerator and the values for the operating parameters for the air 
pollution control devices, respectively. These proposed changes help 
make the part 503 incineration requirements self-implementing. 
Commenters supported the proposed modifications, and they are included 
in today's final rule.
    EPA also proposed to amend Sec. 503.45 (e) to require that the 
maximum combustion temperature for the incinerator, which is based on 
information obtained during the performance test, not be exceeded 
significantly. EPA recognized that the combustion temperature of a 
sewage sludge incinerator could vary. Consequently, the Agency asked 
for comment on: (1) What averaging period should be used to determine 
the maximum allowable combustion temperature (daily average, hourly?) 
and (2) how much the maximum combustion temperature could vary from the 
performance test maximum combustion temperature.
    Commenters' suggestions ranged from measuring maximum operating 
combustion temperature as a hourly average to a daily average, with 
temperature monitored hourly. EPA concluded that the operating 
combustion temperature for a sewage sludge incinerator should be the 
arithmetic mean of the hourly average temperature in the hottest zone 
of the furnace for the hours during the day the incinerator operates, 
and that the maximum allowable operating combustion temperature be 
based on the average combustion temperature during the performance test 
(see discussion below). Any variation in the operating combustion 
temperature over a day is not expected to significantly impact either 
the concentration of a pollutant in the emissions from the sewage 
sludge incinerator or the ambient air concentration for the pollutant 
and, therefore, is not expected to significantly impact public health. 
Thus, EPA is amending the part 503 regulation to add a new definition 
to Sec. 503.41--Special Definitions--for incinerator operating 
combustion temperature as follows: ``Incinerator operating combustion 
temperature is the arithmetic mean of the temperature readings in the 
hottest zone of the furnace recorded in a day (24 hours) when the 
temperature is averaged and recorded at least hourly during the hours 
the incinerator operates in a day.''
    As indicated above, EPA proposed that the maximum allowable 
operating combustion temperature be based on information obtained 
during the incinerator performance test required by Sec. 503.43 (c)(3) 
and (d)(5). The proposed regulation required three separate runs for 
each performance test. Commenters argued that the maximum combustion 
temperature from each of the runs should be averaged to determine the 
maximum combustion temperature for the performance test and that 
temperature should then be increased by a certain percentage (e.g., 20 
percent) to determine the maximum operating combustion temperature.
    EPA agrees that an average should be used to describe the 
combustion temperature in a performance test. The Agency does not 
agree, however, that the maximum temperature from each run should be 
averaged and that average increased by a certain percentage to obtain 
the maximum operating combustion temperature. EPA concluded that the 
performance test combustion temperature should be the arithmetic mean 
of the average combustion temperature in the hottest

[[Page 42561]]

zone of the furnace from each of the runs in a performance test. This 
accounts for variability in the combustion temperature because all of 
the continuously measured temperature readings are used to calculate 
the arithmetic mean. Thus, today's final rule amends Sec. 503.41--
Special Definitions--by adding the following definition for performance 
test combustion temperature: ``Performance test combustion temperature 
is the arithmetic mean of the average combustion temperature in the 
hottest zone of the furnace for each of the runs in a performance 
test.''
    EPA also agrees that the performance test combustion temperature 
should be increased by a certain percentage to determine the maximum 
operating combustion temperature for an incinerator. After further 
review, EPA concluded that a 20 percent increase in the performance 
test combustion temperature is reasonable. The change in control 
efficiency resulting from a 20 percent increase in performance test 
combustion temperature is not expected to be significant because that 
change is not expected to result in a significant change in the 
concentration of a pollutant in the incinerator stack emissions and is 
not expected to result in a significant change in the allowable limit 
for a pollutant (control efficiency is one of the variables used to 
calculate the limit for a pollutant). Because neither the stack 
emissions concentration nor the allowable limit for a pollutant are 
expected to change significantly, public health is not expected to be 
impacted significantly with a 20 percent increase in performance test 
combustion temperature on an average daily basis. This is particularly 
true with respect to the pollutant limits because the limits are 
designed to protect public health from a lifetime of exposure (i.e., 70 
years). In addition, most of the calculated pollutant limits for sewage 
sludge incinerators are higher (sometimes several orders of magnitude 
higher) than the measured sewage sludge concentration for a pollutant. 
Also, as indicated in the report titled ``Human Health Risk Assessment 
for Use & Disposal of Sewage Sludge: Benefits of the Regulation'' (EPA 
822-R-93-005, November 1992), the estimated aggregate risk (i.e., risk 
to the entire exposed population) from exposure to emissions from 
sewage sludge incinerators prior to the establishment of the part 503 
incineration requirements (i.e., baseline risk) is low. Because the 
baseline aggregate risk is low, a 20 percent increase in the 
performance test combustion temperature on an average daily basis is 
not expected to impact the risk to the exposed population from 
incineration of sewage sludge.
    A 20 percent increase also provides flexibility needed to operate a 
sewage sludge incinerator, particularly multiple hearth incinerators. 
In addition, one of the commenters on the proposal recommended a 20 
percent increase even though their recommended increase was in the 
maximum performance test combustion temperature. As mentioned above, 
EPA concluded that it is reasonable to apply the increase to the 
average temperature from the performance test. Thus, Sec. 503.45(e) in 
today's final rule indicates that the arithmetic mean of the 
temperature readings in the hottest zone of the furnace recorded in a 
day when the temperature is average and recorded at least daily (i.e., 
the operating combustion temperature) shall not exceed the arithmetic 
mean of the average combustion temperature in the hottest zone of the 
furnace for each of the runs in the performance test (i.e., the 
performance test combustion temperature) by more than 20 percent.
    Today's final rule amends Sec. 503.45(f) to delete the requirement 
that the permitting authority specify the air pollution control device 
operating parameters. Instead, Sec. 503.45(f) requires that the air 
pollution control device be appropriate for the sewage sludge 
incinerator and that the operating parameters for the air pollution 
control device indicate adequate performance of the device. As 
explained in the preamble to the proposal (60 FR 54780, October 25, 
1995), EPA intended that the values for the air pollution control 
device operating parameters be expressed as a range, and requested 
comment on what the allowable range of values should be relative to the 
values determined during the performance test. EPA also requested 
comments on whether to standardize operating parameters for different 
air pollution control devices in today's final rule. Operating 
parameters for different types of air pollution control devices are 
presented in the ``Technical Support Document for Sewage Sludge 
Incineration'' in section 7.5 and Appendix M (EPA 822/R-93-003, 
November 1992).
    All commenters opposed EPA establishing standardized operating 
parameters in part 503 for the different types of air pollution control 
devices. The operating parameters and the value for the operating 
parameter should be established on a case-by-case basis. However, if 
EPA decides to standardize operating parameters, commenters recommended 
that EPA establish average daily values, and allow flexibility in 
selecting the values for the operating parameters (e.g., allow values 
for the operating parameters that are as low as 70 percent of the 
average daily value in the performance test).
    Because the operating parameters vary depending on the type of air 
pollution control device used and the values for the operating 
parameters depend on site-specific conditions, EPA agrees that those 
parameters and values should be determined on a case-by-case basis. 
Thus, today's Sec. 503.45(f) does not standardize the operating 
parameters for the different types of air pollution control devices.
    Section 503.45(f) in the proposal indicated that operation of the 
sewage sludge incinerator shall not cause a significant exceedence of 
the values for the air pollution control device operating parameters. 
One commenter requested that EPA define ``significant exceedence'' as 
the phrase was used in proposed Sec. 503.45(f). The commenter suggested 
that EPA employ a concept that uses 20 percent and 40 percent ranges to 
define ``significant exceedence.''
    Subpart O of 40 CFR part 60 (Standards for Performance for Sewage 
Sludge Plants) applies to sewage sludge incinerators when the material 
charged is at least 10 percent sewage sludge or when more than 2205 
pounds of sewage sludge are charged per day, and when construction or 
modification of the incinerator commences after June 11, 1973. That 
subpart contains the requirements for the operation of the incinerator 
air pollution control device. For this reason, Sec. 503.45 (f) in 
today's final rule requires that for sewage sludge incinerators subject 
to subpart O of 40 CFR part 60, operation of the air pollution control 
device shall not violate the requirements for the air pollution control 
device in subpart O.
    For all other sewage sludge incinerators, Sec. 503.45 (f) in 
today's final rule indicates that operation of the sewage sludge 
incinerator shall not cause a significant exceedence of the average 
value for the air pollution control device operating parameters from 
the performance tests required by Sec. 503.43 (c)(3) and (d)(5). EPA 
decided not to define ``significant exceedance'' in this case at this 
time. The Agency is considering whether to request comments on the 
allowable ranges for the values for the air pollution control device 
parameters in a subsequent proposal to amend the part 503 regulation.

[[Page 42562]]

    EPA also proposed to add a new section Sec. 503.45(h). As proposed, 
this provision would require that the instruments required in 
Sec. 503.45(a)-(d) be appropriate for the type of sewage sludge 
incinerator, and shall be installed, calibrated, operated, and 
maintained ``consistent with good air pollution control practice for 
minimizing air emissions.'' EPA received only one comment on this 
provision. The commenter argued that the phrase ``consistent with good 
air pollution control practice for minimizing air emissions'' is not 
pertinent. EPA agrees that the requirement to install certain 
instruments for measuring emissions, temperature, etc. is not directly 
related to emissions capture, and has deleted this phrase from the 
final rule.

E. Frequency of Monitoring

    EPA proposed several changes to the frequency of monitoring 
requirements in Sec. 503.46 for sewage sludge incinerators. 60 FR 
54780-82, October 25, 1995.
    1. Mercury and beryllium. In the case of mercury and beryllium 
4, EPA proposed to delete the requirement that the 
permitting authority specify the monitoring frequency, and that the 
frequency be the frequency in the National Emission Standard for 
Hazardous Air Pollutant (NESHAP) for beryllium in subpart C of 40 CFR 
part 61 and in the NESHAP for mercury in subpart E of 40 CFR part 61. 
EPA also requested comment on whether to establish a periodic 
monitoring frequency for beryllium and mercury for sewage sludge 
incinerators that is different from the monitoring frequencies in the 
NESHAP.
---------------------------------------------------------------------------

    \4\ The preamble to the proposal explains the current standards 
and monitoring requirements for incineration of sewage sludge 
containing mercury and beryllium. 60 FR 54780, October 25, 1995.
---------------------------------------------------------------------------

    The October 1995 notice stated that the Agency was considering 
three options for the frequency of monitoring for mercury. The options 
were: (1) Periodic (quarterly or annual) stack or sewage sludge 
sampling, (2) periodic (monthly, quarterly, or annual) sewage sludge 
sampling, and (3) sewage sludge sampling based on the amount of sewage 
sludge fired in a sewage sludge incinerator. For beryllium, EPA 
indicated that periodic stack sampling only for sewage sludge 
incinerators that must comply with the beryllium emission standard in 
40 CFR 61.32(a) was being considered.
    Most of commenters opposed additional beryllium and mercury 
monitoring beyond that required by the current NESHAP for beryllium and 
mercury. One commenter recommended a semi-annual frequency for mercury 
monitoring if mercury in the stack emissions exceeds 1600 grams per day 
(the NESHAP requires annual monitoring if mercury in the stack 
emissions exceeds 1600 grams per day). Another commenter recommended 
sewage sludge sampling for mercury according to the part 503 frequency 
of monitoring for arsenic, cadmium, chromium, lead, and nickel rather 
than stack emission sampling. Another commenter recommended no stack 
sampling and that the monitoring frequency for mercury be based on the 
amount of sewage sludge fired in a sewage sludge incinerator. 
5
---------------------------------------------------------------------------

    \5\ One commenter also requested clarification of the 
applicability of the beryllium NESHAP to sewage sludge incinerators. 
The beryllium NESHAP applies to incinerators that process beryllium-
containing waste, as defined in 40 CFR 61.31(g). Thus, if sewage 
sludge contains beryllium-containing waste and the sewage sludge is 
fired in a sewage sludge incinerator, the sewage sludge incinerator 
is subject to the beryllium NESHAP.
---------------------------------------------------------------------------

    EPA has decided not to establish additional monitoring requirements 
for beryllium and mercury. The Agency concluded that monitoring 
frequencies in the beryllium and mercury NESHAPs are reasonable. Thus, 
today's final regulation amends Sec. 503.46(a)(1) to delete the 
requirement for the permitting authority to designate the frequency of 
monitoring for beryllium and mercury in emissions. The regulation, as 
amended, now provides that the monitoring frequency for beryllium and 
mercury is the frequency in the beryllium and mercury NESHAP, 
respectively.
    Even though the mercury NESHAP only requires annual monitoring if 
mercury in the stack emissions exceeds 1600 grams per day, the 
frequency can be increased on a case-by-case basis by the permitting 
authority when necessary to protect public health and the environment 
(see Sec. 503.5). Thus, in areas like the Great Lakes where mercury 
emissions are a major concern, the monitoring frequency for mercury may 
be increased by the permitting authority, or the person who fires 
sewage sludge in a sewage sludge incinerator could elect to increase 
the mercury monitoring frequency.
    2. Reduction in frequency of sewage sludge monitoring. The October 
1995 notice also proposed to amend Sec. 503.46(a)(3). This section 
currently allows the permitting authority to reduce the frequency of 
monitoring for pollutants after the sewage sludge has been monitored 
for two years at the frequency in Table 1 of Sec. 503.46. In no event, 
however, may monitoring be less frequent than once per year. EPA 
proposed to delete the requirement for monitoring at least once per 
year.
    Commenters supported the proposed change. Thus, for the reasons 
explained above in the previous discussions for the frequency of 
monitoring for land application and surface disposal, today's final 
rule amends Sec. 503.46(a)(3) by deleting the at-least-once-per-year 
monitoring frequency requirement.
    3. Continuous monitoring of THC, oxygen concentration, information 
to determine moisture content, and combustion temperature. As 
previously explained, the current regulation requires continuous 
monitoring of THC, oxygen concentration, information to determine 
moisture content, and combustion temperature. EPA proposed in the 
October 1995 notice to amend this requirement so as to permit 
monitoring at less frequent intervals. The Agency requested comment on 
how to determine when less frequent monitoring should be authorized 
(e.g., should the frequency of monitoring be based on the amount of 
sewage sludge fired annually or on the number of days in a year an 
incinerator operates?).
    All commenters supported the proposed change to delete the 
requirement for continuous monitoring for the four parameters. They 
also offered several recommendations on when to allow less than 
continuous monitoring of the exit gas. Some commenters recommended 
exempting fluidized bed incinerators from the continuous monitoring 
requirement entirely or any incinerator after two years of continuous 
monitoring if the monitoring results indicate minimal THC 
concentrations in the emissions. Others recommended exempting an 
incinerator when the amount of sewage sludge fired is below a specified 
amount or exempting an incinerator if a demonstration can be made that 
temperature can be measured continuously in lieu of measuring THC 
continuously. After reviewing the comments, EPA has decided not to 
adopt any of the recommendations. EPA concluded that the commenters had 
failed to provide adequate technical or scientific support for 
relieving an incinerator from the continuous monitoring requirements. 
The commenters failed to show how compliance with the applicable 
requirements could be demonstrated in the absence of continuous 
monitoring.
    4. Operating parameters for air pollution control devices. As 
explained in the preamble to the proposal (60 FR 54779, October 25, 
1995), and as discussed above, Sec. 503.45 currently requires the 
operation of a sewage

[[Page 42563]]

sludge incinerator's air pollution control device be specified by the 
permitting authority. Section 503.46(c) requires the permitting 
authority to specify the frequency of monitoring for the air pollution 
control device operating parameters. EPA proposed to change 
Sec. 503.46(c) to delete the requirement for the permitting authority 
to specify the monitoring frequency for air pollution control device 
operating parameters and to require that those parameters be monitored 
at least daily. Commenters supported these proposed changes.
    Currently, incinerators that charge more than 10 percent sewage 
sludge (dry weight) or that charge more than 2205 pounds of sewage 
sludge per day; that commence construction or modification after June 
11, 1973; and that have a wet scrubbing device are required to measure 
and record the pressure drop of the gas flow through the wet scrubber 
continuously (see 40 CFR 60.153). Incinerators that meet the first two 
of the above requirements and that have another type of air pollution 
control device also may have to monitor air pollution control device 
operating parameters continuously, if required by the EPA 
Administrator. The Agency decided not to establish additional frequency 
of monitoring requirements in today's final rule for sewage sludge 
incinerators subject to 40 CFR part 60. Thus, the final rule indicates 
for sewage sludge incinerators subject to part 60, the frequency of 
monitoring for the air pollution control device operating parameters 
shall be the frequency of monitoring in subpart O of part 60.
    For all other sewage sludge incinerators, the frequency of 
monitoring for the air pollution control device operating parameters in 
today's rule is at least daily, as proposed. EPA is considering whether 
to establish a continuous monitoring requirement for the air pollution 
control device operating parameters in a subsequent proposal to amend 
the part 503 regulation. Continuous monitoring is consistent with the 
monitoring requirements for air pollution control device operating 
parameters now being considered by other EPA programs. Until a 
different frequency of monitoring requirement is established, however, 
the frequency of monitoring for the air pollution control device 
operating parameters for sewage sludge incinerators not subject to the 
requirements in subpart O of part 60 is at least daily.

F. Recordkeeping

    Today's action amends Sec. 503.47(f) by changing the requirement to 
record the maximum combustion temperature for the sewage sludge 
incinerator to a requirement to record the operating combustion 
temperatures for the sewage sludge incinerator. This change makes 
Sec. 503.47(f) consistent with the new definition of operating 
combustion temperature in Sec. 503.41(i).

VI. Final Amendment to Part 403

    Part 503, as published on February 19, 1993, restricted the total 
chromium concentration of land-applied sewage sludge to prevent 
possible plant injury (i.e., phytotoxicity). On November 15, 1994, the 
U.S. Court of Appeals for the D.C. Circuit remanded the total chromium 
land application pollutant limits for modification or additional 
justification, concluding that EPA lacked an adequate evidentiary basis 
for the risk-based total chromium limits. Leather Industries of America 
v. Environmental Protection Agency, 40 F.3d 392 (DC Cir. 1994). On 
October 25, 1995, EPA promulgated a final rule that deleted total 
chromium from the pollutants regulated when sewage sludge is applied to 
the land (60 FR 54764, October 25, 1995). EPA concluded that there is 
no current basis for establishing total chromium limits for land-
applied sewage sludge.
    At the same time EPA deleted the total chromium limits from the 
part 503 land application requirements, the Agency took two other 
actions. First, EPA removed total chromium from the list of pollutants 
in Appendix G--Section I (40 CFR part 403) for which a removal credit 
is available when sewage sludge is land-applied. EPA removed total 
chromium because the Appendix G--Section I list is limited to those 
pollutants specifically regulated in part 503. Second, to ensure the 
continued eligibility of chromium for a removal credit when sewage 
sludge is land-applied, EPA added a footnote to the table in Appendix 
G--Section II. This table lists pollutants not regulated in part 503 
that are eligible for a removal credit so long as the concentration of 
the pollutant in sewage sludge does not exceed the concentration for 
the pollutant in the table. The footnote stated that determination of a 
concentration limit for total chromium in sewage sludge that is land-
applied would be made on a case-by-case basis. Case-by-case 
determinations would continue until EPA published a concentration for 
total chromium in Appendix G--Section II for land-applied sewage 
sludge.
    EPA reviewed the part 503 land application risk assessment for 
total chromium, and on October 25, 1995, proposed to establish the 
concentration for total chromium for removal credit purposes in 
Appendix G--Section II at 12,000 mg/kg (60 FR 54771). This is the value 
determined to be protective of ground water in the part 503 land 
application risk assessment. The ground-water pathway was the pathway 
that resulted in the most stringent limit for total chromium after the 
phytotoxicity and animal grazing pathways were found to be 
inappropriate (see EPA's reanalysis of the exposure pathways for total 
chromium in land-applied sewage sludge in the docket for the October 
25, 1995, proposal). Several comments were received on the proposal.
    One commenter stated that a numerical value for total chromium in 
Appendix G--Section II for land-applied sewage sludge is not necessary 
as a condition for granting a removal credit for total chromium. The 
commenter believes that the Clean Water Act, as amended, provides EPA 
the authority to grant a removal credit without having a numerical 
value for the pollutant in Appendix G--Sections I or II. EPA disagrees 
with this comment. EPA's position is that a numerical value for the 
pollutant must be established in Appendix G--Sections I or II for the 
POTW to be able to grant a removal credit to the indirect discharger 
for that pollutant. As articulated in the preamble to EPA's recent 
pretreatment streamlining rule, a POTW or industrial user can currently 
petition the Agency to establish a Part 503 standard or an amendment to 
Part 403, Appendix G--Section II for a pollutant along with an analysis 
of the impact of the pollutant on the use or disposal of its sewage 
sludge. Upon promulgation of the Part 503 standard or listing of the 
pollutant in Part 403, Appendix G--Section II, the pollutant would be 
eligible for inclusion in an application for a removal credit.
    With respect to the numerical limit for total chromium, several 
commenters took issue with some of the assumptions underlying the 
proposed numeric limit in Appendix G--Section II. Specifically, the 
commenters indicated that there are problems with the Agency's land 
application ground-water pathway exposure assessment, which was the 
basis for the proposed numerical value for total chromium in land-
applied sewage sludge in Appendix G--Section II. In the commenters' 
views, the values for the land application site parameters and the 
pollutant-specific parameters used in the ground-water pathway analysis 
are too conservative. Moreover, the commenters believe that EPA's 
assessment erroneously relied on parameters associated with chromium

[[Page 42564]]

in its hexavalent form rather than in the trivalent form.
    EPA disagrees that the values for the land application site 
parameters (i.e., soil type, depth to groundwater, and thickness of 
aquifer) used in the ground-water pathway exposure analysis are too 
conservative. Because food crops are grown in sandy soils and because 
sewage sludge is applied to sandy soils, the Agency assumed sand, which 
has a high pollutant transmission potential, as the soil type when 
evaluating the ground-water pathway. Likewise, it is not unreasonable 
to assume that there will be circumstances in which crops will be grown 
on land that has a depth to groundwater of one meter. Similarly, it is 
likely that in dryer climates the thickness of the aquifer below the 
application site could be as small as one meter. Given the potential 
for land application in such conditions, the values EPA used for the 
site parameters in the ground-water pathway analysis are reasonable.
    EPA agrees, however, that the numerical values for pollutant-
specific parameters used in the ground-water pathway analysis are 
inappropriate for modeling either trivalent chromium or total chromium. 
This is because the numerical value for the human health endpoint 
(i.e., maximum contaminant level) used in the ground-water pathway 
analysis is based on exposure to hexavalent chromium (see 56 FR 3537, 
January 30, 1991), and because the numerical value for the partition 
coefficient (KD value) used in the ground-water pathway analysis is 
what would be expected for hexavalent chromium. EPA concluded, 
therefore, that the 12,000 mg-chromium/kg-sewage sludge value proposed 
for total chromium in Appendix G--Section II on October 25, 1995, is 
for the hexavalent form of chromium in sewage sludge that is land-
applied.
    Given that the 12,000 mg/kg concentration is for hexavalent 
chromium only, EPA could either establish the concentration limit in 
Appendix G--Section II for hexavalent chromium, or determine an 
appropriate concentration for total chromium. EPA rejected the option 
of setting a concentration limit for hexavalent chromium only. It is 
extremely difficult to determine the concentration of hexavalent 
chromium in sewage sludge for two reasons. First, it is present in 
sewage sludge at very low levels relative to trivalent chromium levels. 
Second, hexavalent chromium's high chemical reactivity characteristics 
make it extremely difficult to quantify in analytical procedures. 
Therefore, EPA concluded that the chromium limit for land-applied 
sewage sludge on the list in Appendix G--Section II should be for total 
chromium.
    To determine a limit for total chromium, which represents a mixture 
of both hexavalent and trivalent chromium, EPA had to determine 
concentrations for both hexavalent chromium and trivalent chromium that 
do not cause a reasonably anticipated adverse effect. As noted above, 
EPA already determined that if the hexavalent chromium concentration 
does not exceed 12,000 mg/kg, hexavalent chromium in sewage sludge that 
is land-applied will not have an adverse effect on public health and 
the environment. For trivalent chromium, formal ground-water modeling 
has not been performed. Therefore, EPA derived the concentration value 
for trivalent chromium for the ground-water pathway based on some 
assumptions.
    EPA made two assumptions in using a simple model to determine the 
trivalent chromium concentration. First, the Agency assumed that all of 
the values for the land application site parameters in the ground-water 
model for hexavalent chromium are the same for trivalent chromium. That 
is, the soil type is sand, the depth to groundwater is one meter, and 
the thickness of the aquifer is one meter.
    Second, EPA assumed that, with the exception of the oral reference 
dose (RfD), the pollutant-specific parameters for hexavalent chromium 
are the same for trivalent chromium, including the KD value of 59 l/kg. 
The RfD for hexavalent chromium used to derive the human health 
endpoint in the ground-water pathway is 5 x 10-3 mg/kg-day. 
The RfD for trivalent chromium is 1 mg/kg-day--some 200 times greater. 
Because the ratio of the numerical values for the RfDs of trivalent to 
hexavalent chromium is 200, with all other land application site 
parameters and pollutant-specific parameters being equal for the two 
chromium valence species, the estimated allowable concentration value 
for trivalent chromium in sewage sludge is 200 times the allowable 
concentration for hexavalent chromium or 2,400,000 mg/kg. This is only 
a theoretical value because the actual concentration can never exceed 
one million milligrams per kilogram.
    The above theoretical concentration for trivalent chromium is an 
extremely conservative estimate based on many comments that stated that 
the KD values for trivalent chromium are reported as high as several 
thousand l/kg. If KD values like these are used in the analysis, the 
estimated theoretical concentration for trivalent chromium would be 
higher.
    As indicated in the Technical Support Document for Land Application 
of Sewage Sludge (EPA 822/R-93-001a, November 1992) on page 5-107, 
sewage sludge contains little, if any, hexavalent chromium because 
hexavalent chromium is reduced to trivalent chromium during sewage 
sludge treatment. Thus, EPA believes the concentration of hexavalent 
chromium in sewage sludge compared to the concentration of trivalent 
chromium is negligible. At most, hexavalent chromium should not exceed 
one percent (i.e., 10,000 mg/kg) of the total chromium in sewage 
sludge.
    EPA is today establishing the total chromium concentration in 
Appendix G--Section II for land-applied sewage sludge at 100,000 mg/kg. 
The Agency concluded that, although trivalent chromium is the prevalent 
form of chromium in sewage sludge, it is the hexavalent form of 
chromium that the total chromium concentration for land-applied sewage 
sludge must limit. Two commenters recommended a concentration of 
100,000 mg/kg as appropriate to protect ground water from total 
chromium in land-applied sewage sludge. This concentration is 
consistent with the total chromium concentration limit established for 
granting a removal credit for sewage sludge placed in a lined active 
sewage sludge unit. Because the percentage of hexavalent chromium in 
total chromium is expected to be less than one percent, there is 
virtually no potential that the hexavalent chromium concentration in 
land-applied sewage sludge will exceed the allowable concentration for 
hexavalent chromium (i.e, 12,000 mg/kg) in the 100,000 mg/kg total 
chromium concentration limit.
    A total chromium concentration of 100,000 mg/kg in land-applied 
total chromium also ensures that the total chromium limit from other 
pathways in the part 503 land application risk assessment is not 
exceeded. For example, the total chromium limit for the animal grazing 
pathway is 190,000 mg/kg, which is almost twice the total chromium 
concentration in Appendix G--Section II in today's rulemaking.
    Finally, it is important to note that the value for total chromium 
the Agency is adopting today in Appendix G--Section II for land-applied 
sewage sludge is 1-2 orders of magnitude greater than the highest 
concentration of total chromium ever measured in sewage sludge based on 
the results of the 1989 National Sewage Sludge Survey. This too should 
ensure that the granting of a removal credit for total chromium will 
not

[[Page 42565]]

adversely affect public health and environmental when sewage sludge is 
applied to the land.

VII. Regulatory Requirements

A. Executive Order 12866, Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether a regulatory action is ``significant'' 
and therefore subject to review by the Office of Management and Budget 
(OMB) and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal government or communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    It has been determined that this final rule is not a 
``significant'' regulatory action under the terms of Executive Order 
12866 and is not subject, therefore, to OMB review. Further, because 
the effect of today's rule is to modify current requirements and 
provide additional flexibility to the regulated community in complying 
with the part 503 requirements, and to allow a removal credit for 
chromium in land applied sewage sludge under part 403, costs to the 
regulated community should be reduced or at least remain unchanged.

B. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act (RFA), 5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act, 
EPA generally is required to conduct a regulatory flexibility analysis 
describing the impact of the regulatory action on small entities as 
part of rulemaking. However, under section 605(b) of the RFA, if EPA 
certifies that the rule will not have a significant economic impact on 
a substantial number of small entities, EPA is not required to prepare 
a regulatory flexibility analysis. Pursuant to section 605(b) of the 
Regulatory Flexibility Act, 5 U.S.C. 605(b), the Administrator 
certifies that this rule will not have a significant economic impact on 
a substantial number of small entities.
    This action to amend the part 503 regulation provides added 
flexibility in complying with the part 503 requirements and technical 
clarification for some of the requirements. For example, the permitting 
authority has been given the discretion to reduce the frequency of 
monitoring for some of the pollutants subject to the rule. Today's 
action also makes the incineration requirements self-implementing by 
specifying how an incinerator owner/operator is to determine pollutant 
limits applicable to sewage sludge to be combusted. The incineration 
amendments include requirements to provide notice to the permitting 
authority prior to performance testing and to report information that 
was previously obtained by the permitting authority during the 
permitting process. These requirements involve minimal additional cost, 
because the requirements to develop the information needed to calculate 
the pollutant limits are not new. Only the need to provide prior notice 
of testing and to report the results are new, and these requirements 
involve little expense.
    In addition, this action amends the part 403 regulation to 
establish a total chromium in sewage sludge concentration to allow a 
wastewater treatment works to issue a removal credit for chromium in 
land applied sewage sludge. This relieves the wastewater treatment 
works from having to perform a site-specific evaluation and calculation 
to establish a total chromium concentration in sewage sludge in order 
to issue a pre-treatment removal credit for chromium to an industrial 
discharger. As such, the amendments impose no significant new 
requirements on the regulated community, including small entities.
    Accordingly, I certify that this regulation will not have a 
significant economic impact on a substantial number of small entities. 
Therefore, this final regulation does not require a regulatory 
flexibility analysis.

C. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 30 days after it is published in the Federal 
Register. This rule is not a ``major rule'' as defined by 5 U.S.C. 
Sec. 804(2). This rule will be effective September 3, 1999.

D. Paperwork Reduction Act

    The information collection requirements for existing 40 CFR part 
503 were approved by OMB under the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. OMB approved the information collection requirements for 
the existing regulation (part 503) and assigned OMB Control Nos. 2040-
0004 and 2040-0086. Today's action amending part 503 reduces 
information collection requirements in part 503 by allowing the 
permitting authority to reduce the frequency of monitoring for certain 
part 503 pollutants.
    However, today's action also adds a new notice requirement in 
Sec. 503.43(e). The information collection request for this new 
provision is currently under development. EPA expects to publish a 
proposed Information Collection Request (ICR) for these requirements in 
the Federal Register for comment within the next 60 days. The ICR will 
be submitted for approval to the Office of Management and Budget (OMB) 
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. after public 
comment. The information requirements will be published in the Federal 
Register again for public comment when EPA submits them to OMB for 
review and approval. An agency may not conduct or sponsor, and a person 
is not required to respond to a collection of information unless it 
displays a currently valid OMB control number. The OMB control numbers 
for EPA's regulations are listed in 40 CFR part 9 and 48 CFR chapter 
15.

E. Unfunded Mandate Reform Act

    Title II of the Unfunded Mandate Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before

[[Page 42566]]

promulgating an EPA rule for which a written statement is needed, 
section 205 of the UMRA generally requires EPA to identify and consider 
a reasonable number of regulatory alternatives and adopt the least 
costly, most cost-effective or least burdensome alternative that 
achieves the objectives of the rule. The provisions of section 205 do 
not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted.
    Before EPA establishes any regulatory requirements that may 
significantly or uniquely affect small governments, including tribal 
governments, it must have developed under section 203 of the UMRA a 
small government agency plan. The plan must provide for notifying 
potentially affected small governments, enabling officials of affected 
small governments to have meaningful and timely input in the 
development of EPA regulatory proposals with significant Federal 
intergovernmental mandates, and informing, educating, and advising 
small governments on compliance with the regulatory requirements.
    EPA has determined that today's amendments do not contain a Federal 
mandate that may result in expenditures of $100 million or more for 
State, local, and tribal governments, in the aggregate, or the private 
sector in any one year. The final amendments either clarify existing 
regulatory requirements or provide additional flexibility to the 
regulated community in complying with current part 503 requirements and 
allow for the issuance of removal credits under part 403.
    For example, EPA is making a number of changes to reduce the 
reporting and recordkeeping burden of the current requirements. These 
include an amendment to authorize the permitting authority to reduce 
the frequency of monitoring of sewage sludge for pollutants and certain 
pathogen density requirements. In addition, the amendments modify the 
provision to certify that compliance with certain requirements was 
achieved. Under today's amendment, a person certifies to the accuracy 
of the submitted information and not, as is the case at present, to 
compliance with regulatory requirements.
    Today's amendments also delete the language from the current 
regulation that requires the permitting authority to specify certain 
factors used to calculate site-specific pollutant limits for sewage 
sludge incinerators and to specify how to install, calibrate, operate, 
and maintain incinerator continuous emission monitors. Instead, the 
rule contains the information needed by the incinerator owner/operator 
to make the site-specific calculations and properly monitor emissions 
of total hydrocarbons. These self-implementing provisions contain a 
one-time requirement for the owner/operator to provide notice and 
report calculations which were previously obtained from the permitting 
authority. In addition, today's amendments contain technical changes 
that correct inaccurate cross-references and add omitted reporting 
dates and inadvertently omitted phrases. Therefore, to the extent that 
today's final regulation reduces the costs of complying with the 
current part 503 requirements and allow for the issuance of removal 
credits under part 403, the final regulation will lessen the regulatory 
burden on State, local, and tribal governments and the private sector.
    As noted above, there are minimal costs or reduced costs associated 
with the other changes in today's final amendments. Thus, today's 
amendments are not subject to the requirements of sections 202 and 205 
of the UMRA.
    EPA has determined that today's amendments contain no regulatory 
requirements that might significantly or uniquely affect small 
governments. The final amendments do not significantly affect small 
governments because, as explained above, the amendments provide 
additional flexibility in complying with existing regulatory 
requirements, provide for self-implementation, or clarify those 
requirements. The final amendments also do not uniquely affect small 
governments because the changes are applicable to facilities operated 
by small governments to the same extent they are to other sewage sludge 
preparers and users or disposers. Thus this rule is not subject to the 
requirements of section 203 of UMRA.

F. Executive Order 12875, Enhancing Intergovernmental Partnerships

    Under Executive Order 12875, EPA may not issue a regulation that is 
not required by statute and that creates a mandate on a State, local, 
or tribal government, unless the Federal government provides the funds 
necessary to pay the direct compliance costs incurred by those 
governments, or EPA consults with those governments. If EPA complies by 
consulting, Executive Order 12875 requires EPA to provide to the Office 
of Management and Budget a description of the extent of EPA's prior 
consultation with representatives of affected State, local, and tribal 
governments, the nature of their concerns, any written communications 
from the governments, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 12875 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of State, local, and tribal governments ``to provide 
meaningful and timely input in the development of regulatory proposals 
containing significant unfunded mandates.''
    EPA has concluded that this rule will create a mandate on State, 
local, and tribal governments and that the Federal government will not 
provide the funds necessary to pay the direct costs incurred by the 
State, local and/or tribal governments in complying with the mandate. 
However, the mandate created by these amendments to parts 503 and 403 
will have only a minimal impact on these governments as described in 
sections VII A and E of this preamble.
    In developing this rule, EPA consulted with State, local, and 
tribal governments to enable them to provide meaningful and timely 
input in the development of this rule. Over the past three years in the 
development of this rule, EPA on numerous occasions has had 
communication with State, local, and tribal governments on this rule. 
EPA has solicited and received suggestions for improving its 
implementation. This outreach effort culminated in the formation of a 
National Biosolids (Sewage Sludge) Partnership which serves as an 
accessible forum for these exchanges to take place. The representatives 
of these governments have expressed their approval of this 
communications process.
    The concerns of these governments as this rule was developed 
centered around their need to have greater flexibility in complying 
with certain provisions of the original part 503 rule. EPA recognized 
these governments' concerns by providing an option for the permitting 
authority to allow for a reduction in the frequency of monitoring of 
certain part 503 pollutants and allowing for increased flexibility in 
complying with certain pathogen and vector attraction reduction 
requirements in the part 503 rule. EPA's conclusion is that the 
incorporation of these provisions of increased flexibility into the 
part 503 rule still results in adequate protection of public health and 
the environment from pollutants in land applied sewage sludge.

[[Page 42567]]

G. Executive Order 13084, Consultation and Coordination With Indian 
Tribal Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of Indian tribal governments ``to provide meaningful 
and timely input in the development of regulatory policies on matters 
that significantly or uniquely affect their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments and it does not impose 
substantial direct compliance costs on them. The amendments clarify 
existing part 503 requirements and provide the regulated community 
additional flexibility in complying with the regulatory requirements 
and make other requirements self-implementing. In addition, the 
amendment to part 403 allows for the issuance of a removal credit for 
chromium when sewage sludge is land applied, thereby reducing a 
regulatory burden to the private sector. As explained in sections VII A 
and E in this preamble, today's changes do not impose substantial 
direct costs. Accordingly, the requirements of section 3(b) of 
Executive Order 13084 do not apply to this rule.

H. Executive Order 13045, Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any 
rule initiated after April 21, 1997, or proposed after April 21, 1998, 
that: (1) Is determined to be ``economically significant'' as defined 
under EO 12866, and (2) concerns an environmental health or safety risk 
that EPA has reason to believe may have a disproportionate effect on 
children. If the regulatory action meets both criteria, the agency must 
evaluate the environmental health or safety effects of the planned rule 
on children, and explain why the planned regulation is preferable to 
other potentially effective and reasonably feasible alternatives 
considered by the Agency.
    Because this rule was proposed on October 25, 1995, it is not 
subject to EO 13045. Also as explained in the section on EO 12866, 
today's final rule is not an economically significant rule. In 
addition, EPA does not have reason to believe that today's amendments 
pose any environmental health or safety risks presenting a 
disproportionate risk to children. However, EPA reviewed the impact of 
this rule on children's health in light of the Agency's Policy on 
Evaluating Health Risks to Children.
    Today's amendments to part 503 do not alter any of the existing 
part 503 pollutant limits, which are based on the results of the risk 
assessments undertaken for the part 503 rule as published on February 
19, 1993 (58 FR 9248). Today's amendment to part 403 establishes a 
limit for total chromium in land-applied sewage sludge for the purpose 
of granting a removal credit. That limit is based on the results of the 
ground-water pathway analysis. A child is protected in this case 
because the limit based on the ground-water pathway results is more 
stringent than the limit based on the results of the child ingestion 
pathway.

I. National Technology Transfer and Advancement Act

    Under section 12(d) of the National Technology Transfer and 
Advancement Act (``NTTAA''), the Agency is required to use voluntary 
consensus standards in its regulatory activities unless to do so would 
be inconsistent with applicable law or otherwise impractical. Voluntary 
consensus standards are technical standards (e.g., materials 
specifications, test methods, sampling procedures, business practices, 
etc.) that are developed or adopted by voluntary consensus standards 
bodies. Where available and potentially applicable voluntary concensus 
standards are not used by EPA, the Act requires the Agency to provide 
Congress, through OMB, an explanation of the reasons for not using such 
standards.
    Today's final rule does not involve technical standards. Therefore, 
EPA did not consider the use of any voluntary consensus standards.

List of Subjects

40 CFR Part 403

    Environmental protection, Incineration, Land application, 
Pollutants, Removal credits, Sewage sludge, Surface disposal.

40 CFR Part 503

    Environmental protection, Frequency of monitoring, Incineration, 
Land application, Management practices, Pathogens, Pollutants, 
Reporting and recordkeeping requirements, Surface disposal, Vector 
attraction reduction.

    Dated: July 15, 1999.
Carol M. Browner,
Administrator.

    For the reasons set out in the preamble, title 40 of the Code of 
Federal Regulations is amended as set forth below:

PART 403--GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW 
SOURCES OF POLLUTION

    1. The authority citation for part 403 continues to read as 
follows:

    Authority: 33 U.S.C. 1251 et seq.

    2. Appendix G to part 403 is amended by revising section II to read 
as follows:

Appendix G to Part 403--Pollutants Eligible for a Removal Credit

* * * * *

                             II. Additional Pollutants Eligible for a Removal Credit
                                   [Milligrams per kilogram--dry weight basis]
----------------------------------------------------------------------------------------------------------------
                                                                         Use or disposal practice
                                                         -------------------------------------------------------
                        Pollutant                                              Surface disposal
                                                               LA      --------------------------------     I
                                                                          Unlined \1\      Lined \2\
----------------------------------------------------------------------------------------------------------------
Arsenic.................................................  ............  ..............     \3\ 100      ........

[[Page 42568]]

Aldrin/Dieldrin (Total).................................           2.7  ..............  ..............  ........
Benzene.................................................      \3\ 16           140            3400      ........
Benzo(a)pyrene..........................................          15       \3\ 100         \3\ 100      ........
Bis(2-ethylhexyl)phthalate..............................  ............     \3\ 100         \3\ 100      ........
Cadmium.................................................  ............     \3\ 100         \3\ 100      ........
Chlordane...............................................          86       \3\ 100         \3\ 100      ........
Chromium (total)........................................     \3\ 100    ..............     \3\ 100      ........
Copper..................................................  ............      \3\ 46             100        1400
DDD, DDE, DDT (Total)...................................           1.2        2000            2000      ........
2,4 Dichlorophenoxy-acetic acid.........................  ............           7               7      ........
Fluoride................................................         730    ..............  ..............  ........
Heptachlor..............................................           7.4  ..............  ..............  ........
Hexachlorobenzene.......................................          29    ..............  ..............  ........
Hexachlorobutadiene.....................................         600    ..............  ..............  ........
Iron....................................................      \3\ 78    ..............  ..............  ........
Lead....................................................  ............     \3\ 100         \3\ 100      ........
Lindane.................................................          84        \3\ 28          \3\ 28      ........
Malathion...............................................  ............           0.63            0.63   ........
Mercury.................................................  ............     \3\ 100         \3\ 100      ........
Molybdenum..............................................  ............          40              40      ........
Nickel..................................................  ............  ..............     \3\ 100      ........
N-Nitrosodimethylamine..................................           2.1           0.088           0.088  ........
Pentachlorophenol.......................................          30    ..............  ..............  ........
Phenol..................................................  ............          82              82      ........
Polychlorinated biphenyls...............................           4.6         <50             <50      ........
Selenium................................................  ............           4.8             4.8         4.8
Toxaphene...............................................          10        \3\ 26          \3\ 26      ........
Trichloroethylene.......................................      \3\ 10          9500          \3\ 10      ........
Zinc....................................................  ............        4500            4500       4500
----------------------------------------------------------------------------------------------------------------
\1\ Active sewage sludge unit without a liner and leachate collection system.
\2\ Active sewage sludge unit with a liner and leachate collection system.
\3\ Value expressed in grams per kilogram--dry weight basis.
Key: LA--land application.
I--incineration.

PART 503--STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE

    1. The authority citation for part 503 continues to read as 
follows:

    Authority: Sections 405(d) and (e) of the Clean Water Act, as 
amended by Pub. L. 95-217, Sec. 54(d), 91 Stat. 1591 (33 U.S.C. 1345 
(d) and (e)); and Pub. L. 100-4, Title IV, Sec. 406(a), (b), 101 
Stat., 71, 72 (33 U.S.C. 1251 et seq.)

    2. Section 503.2 is amended by adding a new paragraph (d) to read 
as follows:


Sec. 503.2  Compliance period.

* * * * *
    (d) Unless otherwise specified in subpart E, compliance with the 
requirements in Secs. 503.41(c) through (r), 503.43(c), (d) and (e), 
503.45(a)(1), (b) through (f), 503.46(a)(1), (a)(3), and (c), and 
503.47(f) that were revised on September 3, 1999 shall be achieved as 
expeditiously as practicable, but in no case later than September 5, 
2000. When new pollution control facilities must be constructed to 
comply with the revised requirements in subpart E, compliance with the 
revised requirements shall be achieved as expeditiously as practicable 
but no later than September 4, 2001.
    3. Section 503.10 is amended by revising paragraphs (b)(1), (c)(1), 
(d), (e), (f), and (g) to read as follows:


Sec. 503.10  Applicability.

* * * * *
    (b)(1) Bulk sewage sludge. The general requirements in Sec. 503.12 
and the management practices in Sec. 503.14 do not apply when bulk 
sewage sludge is applied to the land if the bulk sewage sludge meets 
the ceiling concentrations in Table 1 of Sec. 503.13 and the pollutant 
concentrations in Table 3 of Sec. 503.13; the Class A pathogen 
requirements in Sec. 503.32(a); and one of the vector attraction 
reduction requirements in Sec. 503.33(b)(1) through (b)(8).
* * * * *
    (c)(1) The general requirements in Sec. 503.12 and the management 
practices in Sec. 503.14 do not apply when a bulk material derived from 
sewage sludge is applied to the land if the derived bulk material meets 
the ceiling concentrations in Table 1 of Sec. 503.13 and the pollutant 
concentrations in Table 3 of Sec. 503.13; the Class A pathogen 
requirements in Sec. 503.32(a); and one of the vector attraction 
reduction requirements in Sec. 503.33(b)(1) through (b)(8).
* * * * *
    (d) The requirements in this subpart do not apply when a bulk 
material derived from sewage sludge is applied to the land if the 
sewage sludge from which the bulk material is derived meets the ceiling 
concentrations in Table 1 of Sec. 503.13 and the pollutant 
concentrations in Table 3 of Sec. 503.13; the Class A pathogen 
requirements in Sec. 503.32(a); and one of the vector attraction 
reduction requirements in Sec. 503.33(b)(1) through (b)(8).
    (e) Sewage sludge sold or given away in a bag or other container 
for

[[Page 42569]]

application to the land. The general requirements in Sec. 503.12 and 
the management practices in Sec. 503.14 do not apply when sewage sludge 
is sold or given away in a bag or other container for application to 
the land if the sewage sludge sold or given away in a bag or other 
container for application to the land meets the ceiling concentrations 
in Table 1 of Sec. 503.13 and the pollutant concentrations in Table 3 
of Sec. 503.13; the Class A pathogen requirements in Sec. 503.32(a); 
and one of the vector attraction reduction requirements in 
Sec. 503.33(b)(1) through (b)(8).
    (f) The general requirements in Sec. 503.12 and the management 
practices in Sec. 503.14 do not apply when a material derived from 
sewage sludge is sold or given away in a bag or other container for 
application to the land if the derived material meets the ceiling 
concentrations in Table 1 of Sec. 503.13 and the pollutant 
concentrations in Table 3 of Sec. 503.13; the Class A pathogen 
requirements in Sec. 503.32(a); and one of the vector attraction 
reduction requirements in Sec. 503.33(b)(1) through (b)(8).
    (g) The requirements in this subpart do not apply when a material 
derived from sewage sludge is sold or given away in a bag or other 
container for application to the land if the sewage sludge from which 
the material is derived meets the ceiling concentrations in Table 1 of 
Sec. 503.13 and the pollutant concentrations in Table 3 of Sec. 503.13; 
the Class A pathogen requirements in Sec. 503.32(a); and one of the 
vector attraction reduction requirements in Sec. 503.33 (b)(1) through 
(b)(8).
    4. Section 503.16 is amended by revising paragraphs (a)(1) and 
(a)(2) to read as follows:


Sec. 503.16  Frequency of monitoring.

    (a) Sewage sludge. (1) The frequency of monitoring for the 
pollutants listed in Table 1, Table 2, Table 3 and Table 4 of 
Sec. 503.13; the pathogen density requirements in Sec. 503.32(a) and 
Sec. 503.32(b)(2); and the vector attraction reduction requirements in 
Sec. 503.33 (b)(1) through (b)(4) and Sec. 503.33 (b)(7) through (b)(8) 
shall be the frequency in Table 1 of Sec. 503.16.

                       Table 1 of Sec.  503.16--Frequency of Monitoring--Land Application
----------------------------------------------------------------------------------------------------------------
  Amount of sewage sludge \1\ (metric tons
            per 365 day period)                                           Frequency
----------------------------------------------------------------------------------------------------------------
Greater than zero but less than 290........  Once per year.
Equal to or greater than 290 but less than   Once per quarter (four times per year).
 1,500.
Equal to or greater than 1,500 but less      Once per 60 days (six times per year).
 than 15,000.
Equal to or greater than 15,000............  Once per month (12 times per year).
----------------------------------------------------------------------------------------------------------------
\1\ Either the amount of bulk sewage sludge applied to the land or the amount of sewage sludge prepared for sale
  or give-away in a bag or other container for application to the land (dry weight basis).

    (2) After the sewage sludge has been monitored for two years at the 
frequency in Table 1 of Sec. 503.16, the permitting authority may 
reduce the frequency of monitoring for pollutant concentrations and for 
the pathogen density requirements in Sec. 503.32(a)(5)(ii) and 
(a)(5)(iii).
* * * * *
    5. Section 503.17 is amended by revising paragraphs (a)(1)(ii), 
(a)(2)(ii), (a)(3)(i)(B), (a)(3)(ii)(A), (a)(4)(i)(B), (a)(4)(ii)(A), 
(a)(5)(i)(B), (a)(5)(ii)(C), (a)(5)(ii)(F), (a)(5)(ii)(H), 
(a)(5)(ii)(J), (a)(5)(ii)(L), (a)(6)(iii), (b)(3), (b)(6), and (b)(7), 
and by adding a new paragraph (a)(4)(ii)(E) to read as follows:


Sec. 503.17  Recordkeeping.

    (a) Sewage sludge. (1) * * *
    (ii) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the Class A pathogen 
requirements in Sec. 503.32(a) and the vector attraction reduction 
requirement in [insert one of the vector attraction reduction 
requirements in Sec. 503.33(b)(1) through Sec. 503.33(b)(8)] was 
prepared under my direction and supervision in accordance with the 
system designed to ensure that qualified personnel properly gather 
and evaluate this information. I am aware that there are significant 
penalties for false certification including the possibility of fine 
and imprisonment.
* * * * *
    (2) * * *
    (ii) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the Class A pathogen 
requirements in Sec. 503.32(a) and the vector attraction reduction 
requirement in (insert one of the vector attraction reduction 
requirements in Sec. 503.33(b)(1) through (b)(8)) was prepared under 
my direction and supervision in accordance with the system designed 
to ensure that qualified personnel properly gather and evaluate this 
information. I am aware that there are significant penalties for 
false certification including the possibility of fine and 
imprisonment.
* * * * *
    (3) * * *
    (i) * * *
    (B) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the Class A pathogen 
requirements in Sec. 503.32(a) was prepared under my direction and 
supervision in accordance with the system designed to ensure that 
qualified personnel properly gather and evaluate this information. I 
am aware that there are significant penalties for false 
certification including the possibility of fine and imprisonment.
* * * * *
    (ii) * * *
    (A) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the management practices in 
Sec. 503.14 and the vector attraction reduction requirement in 
(insert either Sec. 503.33(b)(9) or (b)(10)) was prepared under my 
direction and supervision in accordance with the system designed to 
ensure that qualified personnel properly gather and evaluate this 
information. I am aware that there are significant penalties for 
false certification including the possibility of fine and 
imprisonment.
* * * * *
    (4) * * *
    (i) * * *
    (B) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the Class B pathogen 
requirements in Sec. 503.32(b) and the vector attraction reduction 
requirement in (insert one of the vector attraction reduction 
requirements in Sec. 503.33(b)(1) through (b)(8)if one of those 
requirements is met) was prepared under my direction and supervision 
in accordance with the system designed to ensure that qualified 
personnel properly gather and evaluate this information. I am aware 
that there are significant penalties for false certification 
including the possibility of fine and imprisonment.
* * * * *
    (ii) * * *
    (A) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine

[[Page 42570]]

compliance with the management practices in Sec. 503.14, the site 
restrictions in Sec. 503.32(b)(5), and the vector attraction 
reduction requirement in (insert either Sec. 503.33(b)(9) or (b)(10) 
if one of those requirements is met) was prepared for each site on 
which bulk sewage sludge is applied under my direction and 
supervision in accordance with the system designed to ensure that 
qualified personnel properly gather and evaluate this information. I 
am aware that there are significant penalties for false 
certification including the possibility of fine and imprisonment.
* * * * *
    (E) The date bulk sewage sludge is applied to each site.
    (5) * * *
    (i) *  * *
    (B) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the pathogen requirements in 
(insert either Sec. 503.32(a) or Sec. 503.32(b)) and the vector 
attraction reduction requirement in (insert one of the vector 
attraction reduction requirements in Sec. 503.33(b)(1) through 
(b)(8) if one of those requirements is met) was prepared under my 
direction and supervision in accordance with the system designed to 
ensure that qualified personnel properly gather and evaluate this 
information. I am aware that there are significant penalties for 
false certification including the possibility of fine and 
imprisonment.
* * * * *
    (ii) * * *
    (C) The date bulk sewage sludge is applied to each site.
* * * * *
    (F) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the requirement to obtain 
information in Sec. 503.12(e)(2) was prepared for each site on which 
bulk sewage sludge was applied under my direction and supervision in 
accordance with the system designed to ensure that qualified 
personnel properly gather and evaluate this information. I am aware 
that there are significant penalties for false certification 
including the possibility of fine and imprisonment.
* * * * *
    (H) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the management practices in 
Sec. 503.14 was prepared for each site on which bulk sewage sludge 
was applied under my direction and supervision in accordance with 
the system designed to ensure that qualified personnel properly 
gather and evaluate this information. I am aware that there are 
significant penalties for false certification including the 
possibility of fine and imprisonment.
* * * * *
    (J) The following certification statement when the bulk sewage 
sludge meets the Class B pathogen requirements in Sec. 503.32(b):

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the site restrictions in 
Sec. 503.32(b)(5) for each site on which Class B sewage sludge was 
applied was prepared under my direction and supervision in 
accordance with the system designed to ensure that qualified 
personnel properly gather and evaluate this information. I am aware 
that there are significant penalties for false certification 
including the possibility of fine and imprisonment.
* * * * *
    (L) The following certification statement when the vector 
attraction reduction requirement in either Sec. 503.33(b)(9) or (b)(10) 
is met:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the vector attraction reduction 
requirement in (insert either Sec. 503.33(b)(9) or 
Sec. 503.33(b)(10)) was prepared under my direction and supervision 
in accordance with the system designed to ensure that qualified 
personnel properly gather and evaluate this information. I am aware 
that there are significant penalties for false certification 
including the possibility of fine and imprisonment.
* * * * *
    (6) * * *
    (iii) The following certification statement:

    I certify, under penalty of law, that the information that will be 
used to determine compliance with the management practice in 
Sec. 503.14(e), the Class A pathogen requirement in Sec. 503.32(a), and 
the vector attraction reduction requirement in (insert one of the 
vector attraction reduction requirements in Sec. 503.33(b)(1) through 
Sec. 503.33(b)(8)) was prepared under my direction and supervision in 
accordance with the system designed to ensure that qualified personnel 
properly gather and evaluate this information. I am aware that there 
are significant penalties for false certification including the 
possibility of fine and imprisonment.
* * * * *
    (b) * * *
    (3) The date domestic septage is applied to each site.
* * * * *
    (6) The following certification statement:

    I certify, under penalty of law, that the information that will be 
used to determine compliance with the pathogen requirements (insert 
either Sec. 503.32(c)(1) or Sec. 503.32(c)(2)) and the vector 
attraction reduction requirement in [insert Sec. 503.33(b)(9), 
503.33(b)(10), or Sec. 503.33(b)(12)] was prepared under my direction 
and supervision in accordance with the system designed to ensure that 
qualified personnel properly gather and evaluate this information. I am 
aware that there are significant penalties for false certification 
including the possibility of fine and imprisonment.

    (7) A description of how the pathogen requirements in either 
Sec. 503.32(c)(1) or (c)(2) are met.
* * * * *
    6. Section 503.18 is amended by revising paragraph (a)(2) to read 
as follows:


Sec. 503.18  Reporting.

    (a) * * *
    (2) The information in Sec. 503.17(a)(5)(ii)(A) through 
(a)(5)(ii)(G) on February 19th of each year when 90 percent or more of 
any of the cumulative pollutant loading rates in Table 2 of Sec. 503.13 
is reached at a land application site.
* * * * *
    7. Section 503.21 is amended by revising paragraph (c) to read as 
follows:


Sec. 503.21  Special definitions.

* * * * *
    (c) Contaminate an aquifer means to introduce a substance that 
causes the maximum contaminant level for nitrate in 40 CFR 141.62(b) to 
be exceeded in the ground water or that causes the existing 
concentration of nitrate in ground water to increase when the existing 
concentration of nitrate in the ground water exceeds the maximum 
contaminant level for nitrate in 40 CFR 141.62(b).
* * * * *
    8. Section 503.22 is amended by revising paragraph (b) to read as 
follows:


Sec. 503.22  General requirements.

* * * * *
    (b) An active sewage sludge unit located within 60 meters of a 
fault that has displacement in Holocene time; located in an unstable 
area; or located in a wetland, except as provided in a permit issued 
pursuant to either section 402 or 404 of the CWA, shall close by March 
22, 1994, unless, in the case of an active sewage sludge unit located 
within 60 meters of a fault that has displacement in Holocene time, 
otherwise specified by the permitting authority.
* * * * *
    9. Section 503.26 is amended by revising paragraphs (a)(1) and 
(a)(2) to read as follows:


Sec. 503.26  Frequency of monitoring.

    (a) Sewage sludge (other than domestic septage). (1) The frequency 
of

[[Page 42571]]

monitoring for the pollutants in Tables 1 and 2 of Sec. 503.23; the 
pathogen density requirements in Sec. 503.32(a) and in 
Sec. 503.32(b)(2); and the vector attraction reduction requirements in 
Sec. 503.33(b)(1) through (b)(4) and Sec. 503.33(b)(7) through (b)(8) 
for sewage sludge placed on an active sewage sludge unit shall be the 
frequency in Table 1 of Sec. 503.26.

                       Table 1 of Sec.  503.26.--Frequency of Monitoring--Surface Disposal
----------------------------------------------------------------------------------------------------------------
 Amount of sewage sludge \1\  (metric tons
            per 365 day period)                                           Frequency
----------------------------------------------------------------------------------------------------------------
Greater than zero but less than 290........  Once per year.
Equal to or greater than 290 but less than   Once per quarter (four times per year).
 1,500.
Equal to or greater than 1,500 but less      Once per 60 days (six times per year).
 than 15,000.
Equal to or greater than 15,000............  Once per month (12 times per year).
----------------------------------------------------------------------------------------------------------------
\1\ Amount of sewage sludge placed on an active sewage sludge unit (dry weight basis).

    (2) After the sewage sludge has been monitored for two years at the 
frequency in Table 1 of this section, the permitting authority may 
reduce the frequency of monitoring for pollutant concentrations and for 
the pathogen density requirements in Sec. 503.32(a)(5)(ii) and 
(a)(5)(iii).
* * * * *
    10. Section 503.27 is amended by revising paragraphs (a)(1)(ii), 
(a)(2)(ii), (b)(1)(i), and (b)(2)(i) to read as follows:


Sec. 503.27  Recordkeeping.

    (a) * * *
    (1) * * *
    (ii) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the pathogen requirements in 
(insert Sec. 503.32(a), Sec. 503.32(b)(2), Sec. 503.32(b)(3), or 
Sec. 503.32(b)(4) when one of those requirements is met) and the 
vector attraction reduction requirement in (insert one of the vector 
attraction reduction requirements in Sec. 503.33 (b)(1) through 
(b)(8) if one of those requirements is met) was prepared under my 
direction and supervision in accordance with the system designed to 
ensure that qualified personnel properly gather and evaluate this 
information. I am aware that there are significant penalties for 
false certification including the possibility of fine and 
imprisonment.
* * * * *
    (2) * * *
    (ii) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the management practices in 
Sec. 503.24 and the vector attraction reduction requirement in 
(insert one of the requirements in Sec. 503.33(b)(9) through 
Sec. 503.33(b)(11) if one of those requirements is met) was prepared 
under my direction and supervision in accordance with the system 
designed to ensure that qualified personnel properly gather and 
evaluate this information. I am aware that there are significant 
penalties for false certification including the possibility of fine 
and imprisonment.''
* * * * *
    (b) * * *
    (1) * * *
    (i) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the vector attraction reduction 
requirements in Sec. 503.33(b)(12) was prepared under my direction 
and supervision in accordance with the system designed to ensure 
that qualified personnel properly gather and evaluate this 
information. I am aware that there are significant penalties for 
false certification including the possibility of fine and 
imprisonment.
* * * * *
    (2) * * *
    (i) The following certification statement:

    I certify, under penalty of law, that the information that will 
be used to determine compliance with the management practices in 
Sec. 503.24 and the vector attraction reduction requirements in 
(insert Sec. 503.33(b)(9) through Sec. 503.33(b)(11) if one of those 
requirements is met) was prepared under my direction and supervision 
in accordance with the system designed to ensure that qualified 
personnel properly gather and evaluate this information. I am aware 
that there are significant penalties for false certification 
including the possibility of fine or imprisonment.
* * * * *
    11. Section 503.31 is amended by revising paragraph (g) to read as 
follows:


Sec. 503.31  Special definitions.

* * * * *
    (g) pH means the logarithm of the reciprocal of the hydrogen ion 
concentration measured at 25 deg. Centigrade or measured at another 
temperature and then converted to an equivalent value at 25 deg. 
Centigrade.
* * * * *
    12. Section 503.32 is amended by revising paragraphs (b)(2)(i) and 
(b)(5)(v) to read as follows:


Sec. 503.32  Pathogens.

* * * * *
    (b) * * *
    (2) * * *
    (i) Seven representative samples of the sewage sludge that is used 
or disposed shall be collected.
* * * * *
    (5) * * *
    (v) Animals shall not be grazed on the land for 30 days after 
application of sewage sludge.
* * * * *
    13. Section 503.33 is amended by revising paragraph (b)(10)(i) to 
read as follows:


Sec. 503.33  Vector attraction reduction.

* * * * *
    (b) * * *
    (10)(i) Sewage sludge applied to the land surface or placed on an 
active sewage sludge unit shall be incorporated into the soil within 
six hours after application to or placement on the land, unless 
otherwise specified by the permitting authority.
* * * * *
    14. Section 503.41 is amended by redesignating paragraphs (c), (d), 
(e) (f), (g), (h), (i),(j), (k), (l), (m), (n), and (o) as paragraphs 
(d), (e), (f), (g), (h), (j), (l), (m), (n), (o), (p), (q), and (r), 
respectively, and by adding new paragraphs (c), (i), and (k) to read as 
follows:


Sec. 503.41  Special definitions.

* * * * *
    (c) Average daily concentration is the arithmetic mean of the 
concentration of a pollutant in milligrams per kilogram of sewage 
sludge (dry weight basis) in the samples collected and analyzed in a 
month.
    (i) Incinerator operating combustion temperature is the arithmetic 
mean of the temperature readings in the hottest zone of the furnace 
recorded in a day (24 hours) when the temperature is averaged and 
recorded at least hourly during the hours the incinerator operates in a 
day.
    (k) Performance test combustion temperature is the arithmetic mean 
of

[[Page 42572]]

the average combustion temperature in the hottest zone of the furnace 
for each of the runs in a performance test.
    15. Section 503.43 is amended by revising paragraphs (c) and (d), 
and by adding a new paragraph (e) to read as follows:


Sec. 503.43  Pollutant limits.

* * * * *
    (c) Pollutant limit--lead. (1) The average daily concentration for 
lead in sewage sludge fed to a sewage sludge incinerator shall not 
exceed the concentration calculated using Equation (4).
[GRAPHIC] [TIFF OMITTED] TR04AU99.048

Where:

C = Average daily concentration of lead in sewage sludge.
NAAQS = National Ambient Air Quality Standard for lead in micrograms 
per cubic meter.
DF = Dispersion factor in micrograms per cubic meter per gram per 
second.
CE = Sewage sludge incinerator control efficiency for lead in 
hundredths.
SF = Sewage sludge feed rate in metric tons per day (dry weight basis).

    (2) The dispersion factor (DF) in equation (4) shall be determined 
from an air dispersion model in accordance with Sec. 503.43(e).
    (i) When the sewage sludge stack height is 65 meters or less, the 
actual sewage sludge incinerator stack height shall be used in the air 
dispersion model to determine the dispersion factor (DF) for equation 
(4).
    (ii) When the sewage sludge incinerator stack height exceeds 65 
meters, the creditable stack height shall be determined in accordance 
with 40 CFR 51.100(ii) and the creditable stack height shall be used in 
the air dispersion model to determine the dispersion factor (DF) for 
equation (4).
    (3) The control efficiency (CE) for equation (4) shall be 
determined from a performance test of the sewage sludge incinerator in 
accordance with Sec. 503.43(e).
    (d) Pollutant limit--arsenic, cadmium, chromium, and nickel. (1) 
The average daily concentration for arsenic, cadmium, chromium, and 
nickel in sewage sludge fed to a sewage sludge incinerator each shall 
not exceed the concentration calculated using equation (5).
[GRAPHIC] [TIFF OMITTED] TR04AU99.049

Where:

C = Average daily concentration of arsenic, cadmium, chromium, or 
nickel in sewage sludge.
CE = Sewage sludge incinerator control efficiency for arsenic, cadmium, 
chromium, or nickel in hundredths.
DF = Dispersion factor in micrograms per cubic meter per gram per 
second.
RSC = Risk specific concentration for arsenic, cadmium, chromium, or 
nickel in micrograms per cubic meter.
SF = Sewage sludge feed rate in metric tons per day (dry weight basis).

    (2) The risk specific concentrations for arsenic, cadmium, and 
nickel used in equation (5) shall be obtained from Table 1 of 
Sec. 503.43.

   Table 1 of Sec.  503.43.--Risk Specific Concentration for Arsenic,
                           Cadmium, and Nickel
------------------------------------------------------------------------
                                                           Risk specific
                                                           concentration
                        Pollutant                           (micrograms
                                                             per cubic
                                                               meter)
------------------------------------------------------------------------
Arsenic..................................................          0.023
Cadmium..................................................          0.057
Nickel...................................................          2.0
------------------------------------------------------------------------

    (3) The risk specific concentration for chromium used in equation 
(5) shall be obtained from Table 2 of Sec. 503.43 or shall be 
calculated using equation (6).

   Table 2 of Sec.  503.43.--Risk Specific Concentration For Chromium
------------------------------------------------------------------------
                                                           Risk specific
                                                           concentration
                   Type of Incinerator                      (micrograms
                                                             per cubic
                                                               meter)
------------------------------------------------------------------------
Fluidized bed with wet scrubber..........................          0.65
Fluidized bed with wet scrubber and wet electrostatic              0.23
 precipitator............................................
Other types with wet scrubber............................          0.064
Other types with wet scrubber and wet electrostatic                0.016
 precipitator............................................
------------------------------------------------------------------------

                                                           [GRAPHIC] [TIFF OMITTED] TR04AU99.050
                                                           
Where:

RSC=risk specific concentration for chromium in micrograms per cubic 
meter used in equation (5).
r=decimal fraction of the hexavalent chromium concentration in the 
total chromium concentration measured in the exit gas from the sewage 
sludge incinerator stack in hundredths.

    (4) The dispersion factor (DF) in equation (5) shall be determined 
from an air dispersion model in accordance with Sec. 503.43(e).
    (i) When the sewage sludge incinerator stack height is equal to or 
less than 65 meters, the actual sewage sludge incinerator stack height 
shall be used in the air dispersion model to determine the dispersion 
factor (DF) for equation (5).
    (ii) When the sewage sludge incinerator stack height is greater 
than 65 meters, the creditable stack height shall be determined in 
accordance with 40 CFR 51.100(ii) and the creditable stack height shall 
be used in the air dispersion model to determine the dispersion factor 
(DF) for equation (5).
    (5) The control efficiency (CE) for equation (5) shall be 
determined from a performance test of the sewage sludge incinerator in 
accordance with Sec. 503.43(e).
    (e) Air dispersion modeling and performance testing. (1) The air 
dispersion model used to determine the dispersion factor in Sec. 503.43 
(c)(2) and (d)(4) shall be appropriate for the geographical, physical, 
and population characteristics at the sewage sludge incinerator site. 
The performance test used to determine the control efficiencies in 
Sec. 503.43 (c)(3) and (d)(5) shall be appropriate for the type of 
sewage sludge incinerator.
    (2) For air dispersion modeling initiated after September 3, 1999, 
the modeling results shall be submitted to the permitting authority 30 
days after completion of the modeling. In addition to the modeling 
results, the submission shall include a description of the air 
dispersion model and the values used for the model parameters.
    (3) The following procedures, at a minimum, shall apply in 
conducting performance tests to determine the control efficiencies in 
Sec. 503.43(c)(3) and (d)(5) after September 3, 1999:
    (i) The performance test shall be conducted under representative 
sewage sludge incinerator conditions at the highest expected sewage 
sludge feed rate within the design capacity of the sewage sludge 
incinerator.
    (ii) The permitting authority shall be notified at least 30 days 
prior to any performance test so the permitting authority may have the 
opportunity to observe the test. The notice shall include a test 
protocol with incinerator operating conditions and a list of test 
methods to be used.
    (iii) Each performance test shall consist of three separate runs 
using the applicable test method. The control efficiency for a 
pollutant shall be the arithmetic mean of the control

[[Page 42573]]

efficiencies for the pollutant from the three runs.
    (4) The pollutant limits in Sec. 503.43 (c) and (d) of this section 
shall be submitted to the permitting authority no later than 30 days 
after completion of the air dispersion modeling and performance test.
    (5) Significant changes in geographic or physical characteristics 
at the incinerator site or in incinerator operating conditions require 
new air dispersion modeling or performance testing to determine a new 
dispersion factor or a new control efficiency that will be used to 
calculate revised pollutant limits.
    16. Section 503.45 is amended by revising paragraphs (a)(1), (b), 
(c), (d), (e), and (f), and by adding a new paragraph (h) to read as 
follows:


Sec. 503.45  Management practices.

    (a)(1) An instrument that continuously measures and records the 
total hydrocarbons concentration in the sewage sludge incinerator stack 
exit gas shall be installed, calibrated, operated, and maintained for a 
sewage sludge incinerator.
* * * * *
    (b) An instrument that continuously measures and records the oxygen 
concentration in the sewage sludge incinerator stack exit gas shall be 
installed, calibrated, operated, and maintained for a sewage sludge 
incinerator.
    (c) An instrument that continuously measures and records 
information used to determine the moisture content in the sewage sludge 
incinerator stack exit gas shall be installed, calibrated, operated, 
and maintained for a sewage sludge incinerator.
    (d) An instrument that continuously measures and records combustion 
temperatures shall be installed, calibrated, operated, and maintained 
for a sewage sludge incinerator.
    (e) Operation of a sewage sludge incinerator shall not cause the 
operating combustion temperature for the sewage sludge incinerator to 
exceed the performance test combustion temperature by more than 20 
percent.
    (f) An air pollution control device shall be appropriate for the 
type of sewage sludge incinerator and the operating parameters for the 
air pollution control device shall be adequate to indicate proper 
performance of the air pollution control device. For sewage sludge 
incinerators subject to the requirements in subpart O of 40 CFR part 
60, operation of the air pollution control device shall not violate the 
requirements for the air pollution control device in subpart O of 40 
CFR part 60. For all other sewage sludge incinerators, operation of the 
air pollution control device shall not cause a significant exceedance 
of the average value for the air pollution control device operating 
parameters from the performance test required by Sec. 503.43 (c)(3) and 
(d)(5).
* * * * *
    (h) The instruments required in Sec. 503.45(a)-(d) shall be 
appropriate for the type of sewage sludge incinerator.
    17. Section 503.46 is amended by revising paragraphs (a)(1), 
(a)(3), and (c) to read as follows:


Sec. 503.46  Frequency of monitoring.

    (a) Sewage sludge.
    (1) The frequency of monitoring for beryllium shall be as required 
in subpart C of 40 CFR part 61, and for mercury as required in subpart 
E of 40 CFR part 61.
* * * * *
    (3) After the sewage sludge has been monitored for two years at the 
frequency in Table 1 of Sec. 503.46, the permitting authority may 
reduce the frequency of monitoring for arsenic, cadmium, chromium, 
lead, and nickel.
* * * * *
    (c) Air pollution control device operating parameters.
    For sewage sludge incinerators subject to the requirements in 
subpart O of 40 CFR part 60, the frequency of monitoring for the 
appropriate air pollution control device operating parameters shall be 
the frequency of monitoring in subpart O of 40 CFR part 60. For all 
other sewage sludge incinerators, the appropriate air pollution control 
device operating parameters shall be at least daily.
    18. Section 503.47 is amended by revising paragraph (f) to read as 
follows:


Sec. 503.47  Recordkeeping.

* * * * *
    (f) The operating combustion temperatures for the sewage sludge 
incinerator.
* * * * *
    19. Appendix B to 40 CFR part 503 is amended by revising the 
description No. 6 under B. Processes to Further Reduce Pathogens (PFRP) 
to read as follows:

Appendix B to Part 503--Pathogen Treatment Processes

* * * * *
    B. * * *
    (6) Gamma ray irradiation--Sewage sludge is irradiated with 
gamma rays from certain isotopes, such as \60\ Cobalt and \137\ 
Cesium, at dosages of at least 1.0 megarad at room temperature (ca. 
20 deg. Celsius).
* * * * *
[FR Doc. 99-18604 Filed 8-3-99; 8:45 am]
BILLING CODE 6560-50-P