Standards for the Use or Disposal of Sewage Sludge

SUMMARY: On November 25, 1992, pursuant to Section 405 of the Clean

Water Act (CWA), EPA promulgated the Standards for the Use or Disposal

of Sewage Sludge (40 CFR parts 257, 403 and 503). In addition, EPA

amended the General Pretreatment Regulations (40 CFR part 403) to

establish a list of pollutants for which a removal credit may be

available. Today's action proposes additional amendments to both

regulations to clarify existing regulatory requirements and provide

increased flexibility to the permitting authority and the regulated

community in complying with some requirements.

The proposed amendments to part 503 would modify various land

application, surface disposal, pathogen and vector attraction

reduction, and incineration provisions. Most importantly, the proposed

rule would delete the requirement for EPA or the State to issue sludge

permits and would allow the regulated community flexibility to

determine how to meet the sewage sludge incinerator requirements using

existing Agency guidance. EPA is also proposing to amend part 403 to

add a concentation limit for chromium in the list of unregulated

pollutants eligible for a removal credit. Some of the changes EPA is

proposing today will lessen the regulatory burden on States, local

government, Tribes, and the regulated community.

When EPA promulgated the Sewage Sludge Regulation in 1992, EPA

asked for public comment on several issues. Today's notice also

responds to those comments.

DATES: Comments must be received by December 26, 1995.

ADDRESSES: Send written comments to Comment Clerk; Proposed Amendments

to the Final Sewage Sludge Regulation; Water Docket MC-4101;

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

20460. Respondents are requested to submit an original and three copies

of their written comments. Respondents who want receipt of their

comments acknowledged should include a self-addressed, stamped

envelope. All submissions must be postmarked or delivered by hand, no

facsimiles (faxes) will be accepted.

A copy of the final part 503 rule and comments received on the

final rule are available for review at EPA's Water Docket; 401 M

Street, SW; Washington, DC 20460. Other references cited in the

preamble also are available for review in the Docket. The Docket is

located in room L-102. For access to Docket materials, call (202) 260-

3027 between 9 a.m. and 3:30 p.m. for an appointment. The EPA public

information regulation (40 CFR Part 2) provides that a reasonable fee

may be charged for copying.

FOR FURTHER INFORMATION CONTACT: Robert M. Southworth, Biosolids

Manager, Health and Ecological Criteria Division (4304), Office of

Science and Technology, U.S. Environmental Protection Agency, 401 M

Street, S.W., Washington, D.C. 20460, telephone (202) 260-7157.

SUPPLEMENTARY INFORMATION:

I. Background

A. Sewage Sludge Management Program

B. Revisions to the Part 503 Sewage Sludge Rule

II. Response to Comments on Final Sewage Sludge Rule

A. Field Monitoring Study

B. Pollutant Limits for Cadmium

C. Percent of the MCL for the Ground-Water Pathway

III. Proposed Amendments to Land Application, Surface Disposal, and

Pathogens and Vector Attraction Reduction Subparts

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. Class B Site Restriction For Grazing of Animals

H. Vector Attraction Reduction Equivalency

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

J. Technical Corrections

1. Sec. 503.16(a)(1) and Sec. 503.26(a)(1)--Frequency of

Monitoring

2. Sec. 503.17(b)(7)--Recordkeeping for Land Application of

Domestic Septage

3. Sec. 503.18--Reporting

4. Sec. 503.22(b)--General requirements

5. Sec. 503.32(a)(3)--Pathogens

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

IV. Proposed Amendments to the Incinerator Subpart

A. Introduction

B. Description of Current Regulation and Proposed Amendments

1. Site-Specific Exemption from Frequency of Monitoring,

Recordkeeping, and Reporting Requirements for Pollutants in

Incineration Subpart

a. Current Regulation

b. Proposed Amendment

2. Pollutant Limits for Arsenic, Cadmium, Chromium, Lead and

Nickel

a. Current Regulation

b. Proposed Amendment

3. Management Practices

a. Current Regulation

i. Specification for Instruments

ii. Specification of Maximum Combustion Temperature

iii. Specification of Air Pollution Control Device Operating

Parameters

b. Proposed Amendment

4. Monitoring Frequencies

a. Current Regulation

i. Beryllium, Mercury, and Operating Parameters for Air

Pollution Control Devices

ii. Total Hydrocarbons, Oxygen Concentration, and Moisture

Content

b. Proposed Amendment

5. Recordkeeping and Reporting Obligations

6. Compliance Deadlines

a. Current Regulation

b. Proposed Amendment

V. Proposed Amendment to Part 403

VI. Regulatory Requirements

A. Executive Order 12866

B. Executive Order 12875

C. Regulatory Flexibility Act

D. Paperwork Reduction Act

E. Unfunded Mandates

I. Background

On November 25, 1992, the U.S. Environmental Protection Agency

promulgated, pursuant to section 405 of the Clean Water Act, Standards

for the Use or Disposal of Sewage Sludge (58 FR 9248, February 19,

1993). This regulation establishes requirements to protect public

health and the environment when: (1) The sewage sludge is applied to

the land either to condition the soil or to fertilize crops grown in

the soil; (2) the sewage sludge is disposed on land by placing it in a

surface disposal site; (3) the sewage sludge is placed in a municipal

solid waste landfill unit; or (4) the sewage sludge is incinerated.

Section 405(f) of the Clean Water Act (CWA) provides that any CWA

discharge (section 402) permit issued to a publicly owned treatment

works (POTW) or other treatment works treating domestic sewage (TWTDS)

must include conditions to implement the sewage sludge regulation

issued under section 405(d) unless these conditions are included in

other permits. The other permits may either be other Federal permits or

a State permit issued under an approved State program.

In 1989, EPA published regulations that establish State sewage

sludge management program requirements and procedures for approving

State National Pollutant Discharge Elimination System (NPDES) (40 CFR

part 123) and non-

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NPDES sewage sludge programs (40 CFR part 501), and that revised the

NPDES permit requirements and procedures (parts 122-124) to incorporate

sewage sludge permitting requirements. (See 54 FR 18716 (May 2, 1989);

59 FR 9404 (February 19, 1993).) State assumption of the sewage sludge

program is optional. EPA is working with a number of States seeking

authorization for the Federal sewage sludge permit and management

program, but has not yet authorized any State sewage sludge program.

Until State sewage sludge programs are authorized, EPA will administer

the program.

EPA is including conditions to implement its sewage sludge

regulation in EPA-issued NPDES permits as these permits are reissued.

In all other cases, EPA plans to issue permits to TWTDS over time, and

has established phased application submittal procedures for the NPDES

and non-NPDES programs to support this approach. See 40 CFR 122.21 and

501.15. (For a detailed discussion of EPA's plans for staged permitting

of sewage sludge generators, users, and disposers, see 58 FR at 9249-50

and 9357-66, February 19, 1993.)

In addition to today's proposal, EPA plans several related actions

in the near term to address sewage sludge issues. These actions include

changes in the sewage sludge management program and further revisions

to the part 503 rule. These actions are briefly discussed below.

A. Sewage Sludge Management Program

As part of its effort to reinvent its permit program, EPA is in the

process of reviewing its sewage sludge management program. The Agency

is looking at how to tailor the program more efficiently to reduce the

burden to the regulated community of complying with Federal sewage

sludge management program requirements. With this objective in mind,

EPA is exploring a number of options with stakeholders. Given the wide

(and successful) regulation of sewage sludge use or disposal by a

number of States, EPA is reviewing its State sewage sludge program

authorization regulations to simplify the approval process. In

addition, the Agency will try to accelerate approval of State programs

through the use of partial program approvals (i.e., approval may be

granted by use or disposal practice). EPA will place greater emphasis

on building a State/Federal partnership rather than on an EPA-directed

permitting effort while maintaining its goal of protecting public

health and the environment.

As noted, EPA will be taking a look at its State program approval

regulations with an eye to streamlining the approval process. The

Agency recognizes that State sewage sludge programs may vary from State

to State depending on local conditions. EPA will be exploring how to

provide greater flexibility to States to accommodate States' choices

about the structuring of their regulatory programs and efficient use of

available local resources where appropriate. To accomplish its

objective to provide greater flexibility to the States, EPA will

consider modifications to its sewage sludge permit program regulations

so as to accommodate more variations in State programs. EPA stresses

that its willingness to allow greater variation in the State permit

programs does not mean that the Agency will retreat from public health

and environmental protection. EPA's policy on authorizing State permit

programs for sewage sludge will still reflect the need for certain

minimum requirements. These include requirements for adequate State

authority to enforce against violators of the sewage sludge regulation.

In addition, States, as is now the case, must provide for citizen

participation in both the sewage sludge permitting and enforcement

efforts.

B. Revisions to the Part 503 Sewage Sludge Rule

EPA also is considering whether it needs to provide more

flexibility in the technical standards. A number of parties have

suggested to the Agency that part 503 should include a provision that

would relieve a sewage sludge user or disposer from certain regulatory

requirements in defined circumstances. EPA is now considering what

specific conditions would warrant relief from regulatory requirements.

Further, in addition to its effort to provide more flexibility in the

technical regulation, EPA is reviewing the regulation in response to

judicial challenges. On November 15, 1994, the United States Court of

Appeals for the District of Columbia Circuit issued its decision in

Leather Industries of America, Inc., et al. v. EPA, No. 93-1187. In

this decision, the court addressed several of the petitions for review

of the sewage sludge regulation. The D.C. Circuit remanded several

aspects of the regulation to the Agency for modification or additional

justification. Concurrent with today's proposal, the Agency is taking

final action on the remanded pollutant limits for chromium and selenium

in sewage sludge that is land-applied. Moreover, the Agency will

address other litigation issues in a future Federal Register notice to

be published in early 1996.

The part 503 regulation promulgated in November, 1992, partially

fulfilled the Agency's commitment under the terms of a consent decree

that settled a citizens suit to compel issuance of sewage sludge

regulations. Gearhart, et al. v. Reilly, Civil No. 89-6266-JO (D.Ore).

Under the terms of that decree, EPA must propose and take final action

on a second round of sewage sludge regulations by December 15, 2001.

EPA has already begun the process of evaluating a number of pollutants

for potential adverse effects to public health and the environment when

present in sewage sludge. In May, 1993, pursuant to the terms of the

consent decree in the Gearhart case, the Agency notified the United

States District Court for the District of Oregon that, based on the

information then available, EPA would evaluate 31 pollutants for

possible regulation. The consent decree also stipulates that EPA will

file with the court a revised list of pollutants for regulation by

November, 1995. In the event that EPA determines not to regulate some

or all of these pollutants, EPA will make available the rationale for

not regulating those pollutants.

II. Response to Comments on Final Sewage Sludge Rule

In developing the numerical pollutant limits for sewage sludge when

used or disposed, EPA evaluated the risk of these pollutants through

exposure assessments. In the preamble to the final part 503 regulation,

EPA requested public comment on three issues related to these risk

assessments.

A. Field Monitoring Study

For its risk assessments, EPA relied on available scientific

information to evaluate risk to public health and the environment. In

the case of the Agency's evaluation of ecological risks, the data were

limited. In the final rule, EPA explained that it would continue to

assess the adverse potential of sewage sludge, particularly with

respect to ecosystem risks. EPA stated its intention to conduct an

environmental evaluation and monitoring study to aid the Agency in its

efforts to develop a comprehensive ecological risk assessment

methodology (see 58 FR 9275, February 19, 1993).

At the present time, EPA's Office of Research and Development is

funding a number of initiatives in these areas. Under a grant from EPA,

the Oak Ridge National Laboratory has begun work on an ecological risk

study as part of a field project evaluating sewage sludge land

application. In addition, the Ecosystems Research Division (Athens,

Georgia) in EPA's National Exposure Research Laboratory has started

work to test the

[[Page 54773]]

hypothesis that sewage sludge binds metals in an organic matrix, which

reduces their bioavailability. The Ecosystems Research Division also

will validate the ground-water model used to develop the pollutant

limits for the ground-water exposure pathway for land application and

surface disposal. Further, the Western Ecology Division (Corvallis,

Oregon) in EPA's National Health and Environmental Effects Research

Laboratory is examining issues concerning evaluation of phytotoxic

risk. This will include a review of appropriate measures of

phytotoxicity and studies concerning plant uptake of metals.

EPA received a single comment on the proposed field study for

evaluation of ecological effects. The commenter stressed that it is

critical that realistic exposure scenarios be used. The Agency agrees

with that comment. EPA is currently working with the Oak Ridge National

Laboratory to define the environmental end points of concerns and

reasonable exposure assumptions for the ecological risk study.

B. Pollutant Limits for Cadmium

The Agency received a number of public comments on the final

cadmium pollutant limits for land application. Some comments were

supportive of the final limits for this pollutant. However, a few

commenters expressed some concerns. These concerns fell into two

general categories: (1) The United States Department of Agriculture

(USDA) expressed concern that the final cadmium limits may jeopardize

the export of grains to foreign markets, and (2) other commenters

expressed concern that the risk-based cadmium limits may not be

protective enough. In arguing for lower cadmium limits, commenters

indicated that the limiting exposure pathway, the exposure assumptions,

and the analysis methods used in the risk assessment should be

reevaluated.

With respect to the first issue, EPA believes that the current

cadmium pollutant concentration limit of 39 mg Cd/kg sewage sludge

generally should not be a concern for the export of most grains.

However, because it is possible that some local conditions may cause

cadmium levels to exceed European commodity tolerance levels for grain

crops, EPA and USDA have agreed to develop a joint advisory statement

for farmers who may export grain to the European markets. The advisory

would recommend lower cadmium limits for cropland that may be used to

produce crops for exports.

As requested by some commenters, the Agency has reevaluated the

cadmium risk assessment and has concluded that its risk assessment

approach for cadmium is conservative and defensible. EPA has thoroughly

responded to these comments in the record for today's rulemaking. EPA

continues to believe that the present cadmium pollutant limits are

sufficiently protective of highly exposed individuals. There may be

circumstances where site-specific conditions would suggest that a more

stringent pollutant limit may be more appropriate. However, EPA's

regulatory policy is to use conservative assumptions that will protect

highly exposed individuals. This approach ensures protection against

reasonably anticipated risks, not the risk associated with highly

unlikely or unusual circumstances. The selection of data, assumptions,

and analysis methods used in developing the land application cadmium

pollutant limits are consistent with this policy. After further review,

EPA concluded that the data and methods used in the risk assessment

reflect actual growing conditions found throughout the United States.

As the Agency previously determined, the land application cadmium

pollutant limit adopted for the final rule adequately protects public

health and the environment. EPA has not received any new information

since publication of the final rule that would indicate that a change

in the current cadmium pollutant limit is warranted. Therefore, the

current land application ceiling concentration limit of 85 mg/kg, the

current cumulative pollutant loading rate of 39 kg/ha, the current

pollutant concentration limit of 39 mg/kg, and the current annual

pollutant loading rate of 1.9 kg/ha/365 day period remain in effect.

For additional discussion of the specific risk assessment issues

and EPA's rationale for the final land application cadmium pollutant

limits, EPA refers readers to the Response to Comments Document

available in the docket for this proposed rulemaking.

C. Percent of the MCL for the Ground-Water Pathway

In the final rule, EPA asked for comment on whether, in its

exposure assessments, a percentage of the end point to be protected

(i.e., a Maximum Contaminant Level (MCL)) should be used to develop the

allowable concentration of pollutants in sewage sludge for the ground-

water pathway in both the land application and surface disposal risk

assessments. EPA did not receive any public comments on this issue and

is not, therefore, proposing any corresponding change to the

regulation.

III. Proposed Amendments to Land Application, Surface Disposal, and

Pathogens and Vector Attraction Reduction Subparts

A. Ceiling Concentration Limits--Land Application

Today's notice would amend the applicability section of the land

application requirements to clarify that the ceiling concentration

limits apply to all sewage sludge that is land-applied. While

Sec. 503.13(a)(1) requires that all land-applied sewage sludge must

meet the ceiling concentration limits in Table 1 of Sec. 503.13, the

current language in Sec. 503.10 (b)(1), (c)(1), (d), (e), (f), and (g)

does not expressly require meeting the ceiling concentration limits.

The proposed amendment would remove any ambiguity about the obligation

to comply with ceiling concentration limits for land-applied sewage

sludge.

B. Frequency of Monitoring

Sections 503.16, 503.26, and 503.46 of the current sewage sludge

regulation require that sewage sludge be monitored for certain

pollutants. How frequently sewage sludge must be monitored varies with

the amount of sewage sludge that is used or disposed. The regulation

allows the permitting authority to reduce the monitoring frequency

after the sewage sludge has been monitored for two years. In no case,

however, under the present requirements, may the permitting authority

authorize monitoring less frequently than once per year for each use or

disposal practice.

Today's notice would amend Sec. 503.16, Sec. 503.26, and

Sec. 503.46 to delete the language requiring monitoring of sewage

sludge at least once per year. This amendment would provide additional

flexibility to the permitting authority to reduce the frequency of

monitoring for sewage sludge to less than once per year.

C. Certification Language

Sections 503.17 and 503.27 of the current sewage sludge regulation

require sewage sludge preparers, land appliers, and the owner/operator

of a surface disposal site to keep certain records, and in the case of

Class I sludge management facilities and certain POTWs, to report this

information to the permitting authority. The regulation also requires

the recordkeepers to certify to compliance with all applicable

requirements. Failure to certify may result in significant penalties.

The effect of this requirement may be to discourage self-reporting

of violations. If monitoring measurements indicate that applicable

sewage sludge requirements are not being met, a

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recordkeeper obviously cannot certify to compliance without perjury.

This puts the recordkeeper in the position of either committing perjury

or failing to make the certifications. In either event, the

recordkeeper risks significant penalties.

EPA is proposing to amend the language for the certification

statements in Sec. 503.17 and Sec. 503.27. Under today's proposal, the

recordkeeper would be required to certify only to the accuracy of the

information that will be used to determine compliance with a part 503

requirement and its preparation under the certifier's supervision

rather than to compliance with applicable part 503 requirement.

D. Time of Application

Sections 503.17 (a)(5)(ii)(C) and (b)(3) of the current regulation

require the applier of sewage sludge subject to cumulative pollutant

loading rates and the applier of domestic septage to agricultural land,

forest, or a reclamation site, respectively, to record the time of

application as well as supply certain other information needed to track

the amount of regulated pollutants and the volume of domestic septage

applied to a site. (See Sec. 503.17(a)(5)(ii)( D) and (E);

Sec. 503.17(b)(5), which require recordkeeping on the cumulative amount

of each pollutant applied at the site, the amount of sewage sludge

applied, and the rate at which domestic septage is applied.) The

information on cumulative amounts of pollutants applied is needed so

that subsequent land appliers may determine whether additional amounts

of sewage sludge can be applied at a site without exceeding the

cumulative pollutant loading rate for any pollutant.

Questions have been raised about the meaning of the time of

application requirement as well as the need for this information. After

reviewing this issue, EPA has concluded that information on the time of

application is not needed to track the amount of the part 503

pollutants applied to a site in bulk sewage sludge or the volume of

domestic septage applied to the land. EPA has determined that, with

information identifying the site at which the sewage sludge has been

applied, the total cumulative load of metals at the site and the

quantity of sewage sludge, subsequent sewage sludge appliers will have

all the information needed to comply with the land application

cumulative pollutant loading rates. The time of application also is not

needed when domestic septage is applied to agricultural land, forest,

or a reclamation site. For this reason, today's proposal deletes the

requirement to record the time of application.

Today's proposal does not delete the requirement to record the date

that sewage sludge or domestic septage is applied to site. The date is

needed to know when the site restrictions for Class B sewage sludge

begin and when they end. The date of application also is needed to

determine when site restrictions begin and end when domestic septage is

applied to agricultural land, forest, and reclamation sites.

EPA also is proposing today to amend section 503.17(a)(4)(ii) to

add the requirement that the date of application be kept. This is

needed because in this recordkeeping scenario, the sewage sludge is

Class B with respect to pathogens. When a Class B sewage sludge is land

applied, the date the site restrictions begin and end has to be known.

Adding the requirement to record the date of application will provide

the information needed to know when the site restrictions begin.

E. Definition of pH

EPA is proposing to clarify the definition of pH in Sec. 503.31 in

response to a recommendation received from the National Lime

Association (NLA). The NLA recommended that EPA clarify the definition

of pH to indicate that the pH is expressed at 25 deg. C, the reference

temperature for reporting pH values in the scientific literature.

The pH is very sensitive to temperature, especially at pHs of 12

and above. Certain of the pathogen alternatives and vector attraction

reduction options call for raising the pH of sewage sludge or domestic

septage to 12 or higher by alkali addition. Concern has been expressed

that the pH readings taken after the addition of alkali will be high

for temperatures below 25 deg. C and low for temperatures above 25 deg.

C (i.e., there is an inverse relationship between temperature and pH).

See discussion in 58 FR 46052, August 31, 1993.

Based on the above, the Agency has concluded that the pH of the

sewage sludge or domestic septage must be measured at 25 deg. C or, if

measured at a different temperature, must be converted to an equivalent

value at 25 deg. C. See Smith and Farrell, which provides the following

equation:

pH correction=0.03 pH units/1.0 deg. C X (Temp deg. Cmeas-25 deg.

C).

EPA is proposing to amend the regulation accordingly.

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

EPA has concluded that the requirement in Class B, Alternative 1 does

not have to be met at the time sewage sludge is used or disposed. This

alternative, which requires that the fecal coliform density in the

sewage sludge be less than either 2,000,000 Most Probable Number per

gram of total solids or 2,000,000 Colony Forming Units per gram of

total solids, can be met any time before the sewage sludge is used or

disposed. The site restrictions that have to be met when a Class B

sewage sludge is land applied and the surface disposal management

practices provide the environment time to reduce remaining pathogens in

a Class B sewage sludge to below detectable levels. This proposed

change makes Class B, Alternative 1 consistent with Class B,

Alternatives 2 and 3.

G. Class B Site Restriction for Grazing of Animals

When sewage sludge is used or disposed at a site, the current rule

(Sec. 503.32(b)(5)(v) and Sec. 503. 24(l)) prohibits grazing of animals

at the site in certain circumstances. Controlling access to limit the

exposure of all animals is difficult, if not impossible, to implement.

EPA is accordingly proposing to amend the text of Sec. 503.32(b)(5)(v))

to remove ambiguity in the language. The Agency's intention is to

prohibit intentional, not inadvertent, grazing of animals.

Note, however, that the land application site restriction and

surface disposal management practices that restrict public access may

prevent access to the site for many types of animals depending on how

public access is restricted (e.g., by a fence).

H. Vector Attraction Reduction Equivalency

Sewage sludge has a number of characteristics that may attract

disease-spreading agents like birds, flies and rats. Consequently, the

regulation includes requirements to reduce the potential for attracting

these disease-spreading agents--so-called ``vector attraction

reduction'' requirements. The rule provides a number of options for

achieving the required vector attraction reduction.

The Agency has received requests for additional flexibility in

meeting these requirements similar to that provided in the current

regulation for Class A and Class B pathogen reduction requirements.

Processes other than those prescribed in the regulation may be used to

reduce pathogens if the

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permitting authority determines they are equivalent to a Process to

Further Reduce Pathogens (PFRP) or a Process to Significantly Reduce

Pathogens (PSRP). See 58 FR 9400, February 19, 1993.

Under the current system, the permitting authority must decide

whether a pathogen reduction process is equivalent. Often, the

permitting authority requests assistance in making this decision from

EPA's Pathogen Equivalency Committee (PEC). The PEC, which consists of

representatives from EPA's Office of Research and Development and from

EPA's Office of Water, provides technical assistance on pathogen issues

and makes recommendations on equivalency determinations. The PEC only

makes recommendations on pathogen equivalency determinations. Thus, the

final decision rests with the permitting authority.

EPA is proposing in today's notice to amend Sec. 503.15(c),

Sec. 503.25(b) and Sec. 503.33(a) so as to allow the same flexibility

with respect to the vector attraction reduction options that require

treatment of the sewage sludge. EPA is not proposing to authorize an

equivalency determination for the barrier vector attraction reduction

options (i.e., Options 9 and 10 for land application and Options 9, 10

and 11 for surface disposal) because EPA is unaware of any barrier

options other than those already provided in part 503. Commenters

should submit any information they may have about other options. As

with equivalency for pathogen reduction, the final decision on vector

attraction reduction equivalency will be the responsibility of the

permitting authority. EPA's PEC may assist the permitting authority in

making vector attraction reduction equivalency determinations.

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

Under the current regulation, the vector attraction reduction

options that require treatment of the sewage sludge (i.e., Options 1

through 8) may be met any time before the sewage sludge is used or

disposed. Options 9, 10, and 11 must be met at the time the sewage

sludge is used or disposed. EPA has reviewed these options and

concluded that certain modifications may be needed to protect public

health and the environment and to introduce additional flexibility.

When any of the first five options is employed, the sewage sludge

does not become more attractive to vectors if it is stored before it is

used or disposed. Thus, Options 1 through 5 may appropriately be met

any time before the sewage sludge is used or disposed. However, EPA has

concluded that this may not be true in the case of Options 6, 7, and 8.

Vector attraction reduction achieved by pH adjustment (i.e., Option

6) is not permanent. Adjusting the pH of the sewage sludge to 12 does

not change the characteristics of the sewage sludge significantly, but

instead causes stasis in biological activity. If the pH should drop,

the surviving bacterial spores could become active and the sewage

sludge could putrefy and attract vectors. The target pH conditions in

Option 6 allow the sewage sludge to be stored for several days before

it is used or disposed without the pH dropping.

If quicklime or slaked lime is used to adjust the pH, the pH is not

expected to fall below 12 for up to 25 days after the addition of the

lime. If a different alkali (e.g., cement kiln dust or wood ash) is

used to adjust the pH, the period before which the pH drops may be

different because other alkali materials are more soluble than lime.

Thus, less undissolved material is available to maintain the pH as it

starts to drop.

Because the pH of the sewage sludge could drop after the target

conditions in Option 6 are reached, the Agency is proposing in today's

rulemaking to require that vector attraction reduction Option 6 must be

met at the time the sewage sludge is used or disposed.

Two approaches could be used to meet this proposed requirement.

First, the target pH conditions could be met at any time. Just prior to

use or disposal (e.g., within one or two days), the pH of the sewage

sludge could be checked. If the pH of a representative sample of the

sewage sludge is 11.5 or above, vector attraction reduction is

achieved. If the pH is below 11.5, the pH has to be adjusted again to

reach the target conditions in Option 6 or another vector attraction

reduction option (e.g., incorporation) has to be met. The other

approach is to meet the target conditions in Option 6 at the time of

use or disposal. For example, the pH could be adjusted two days prior

to when the sewage sludge is used or disposed and the target conditions

could be met during those two days.

Vector attraction reduction Options 7 and 8 require that the

percent solids in the sewage sludge be above a certain value. If the

percent solids drops (i.e., moisture content increases), vectors could

be attracted to the sewage sludge. Thus, today's proposal also would

require that vector attraction reduction Options 7 and 8 be met at the

time the sewage sludge is used or disposed.

Vector attraction reduction Option 10 requires incorporation of

sewage sludge into the soil within six hours after it is land applied

or surfaced disposed. This reduces the attraction of vectors to the

sewage sludge by placing a barrier between the sewage sludge and the

vectors. In some cases, it may not be feasible to incorporate the

sewage sludge into the soil within six hours after it is land applied

or surface disposed. Today's proposal would allow the permitting

authority the flexibility to address those cases on a site-specific

basis.

Today's proposal would amend Sec. 503.33 (b)(6), (b)(7), and (b)(8)

by adding language making it clear that these requirements must be met

at a defined time rather than any time before the sewage sludge is used

or disposed.

The proposal also would amend Sec. 503.33(b)(10)(i) to add language

to authorize the permitting authority to specify a different time

period during which sewage sludge has to be incorporated into the soil

after it is land applied or surface disposed. This would allow the

permitting authority to consider site-specific conditions (e.g., the

remoteness of a land application site) that may affect the time period

during which sewage sludge can be incorporated into the soil.

J. Technical Corrections

Today's proposal also contains several technical corrections. The

following proposed amendments are minor in nature and provide

clarification on some of the technical requirements of the final part

503 regulation.

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

Sections 503.16(a)(1) and 503.26(a)(1) contain the requirement for

monitoring for pollutants, pathogen densities, and vector attraction

reduction. Those sections incorrectly indicate there are pathogen

density requirements in Sec. 503.32 (b)(3) and (b)(4). Today's notice

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 incorrectly indicate

that the frequency of monitoring requirements apply to vector

attraction reduction Option 5 in Sec. 503.33(b)(5). Today's notice

deletes the reference to vector attraction reduction Option 5 from

Sec. 503.16(a)(1) and Sec. 503.26(a)(1).

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

Septage

Today's notice amends Sec. 503.17(b)(7) by changing an incorrect

reference.

[[Page 54776]]

3. Sec. 503.18--Reporting

Today's notice corrects the omission of a reporting date in the

current rule by inserting February 19th in Sec. 503.18(a)(2).

4. Sec. 503.22(b)--General Requirements

Today's notice amends Sec. 503.22(b) correcting the statutory

reference and by inserting the appropriate date.

5. Sec. 503.32(a)(3)--Pathogens

Today's notice amends Sec. 503.32(a)(3) to clarify that this option

excludes composting. Class A, Alternative 1 was designed for thermal

processes such as anaerobic digestion and does not apply to composting.

6. 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

inadvertently omitted.

IV. Proposed Amendments to the Incineration Subpart

A. Introduction

A sewage sludge incinerator is a treatment works treating domestic

sewage as defined in 40 CFR 122.2 and 501.2. In most cases, the

treatment works generating the sewage sludge operates the sewage sludge

incinerator so that a permit issued to the generating treatment works

will contain the part 503 requirements applicable to its incinerator.

Subpart E of part 503, 40 CFR 503.40-503.48, establishes the

technical requirements for the incineration of sewage sludge. Under

section 405 of the CWA, EPA must establish adequately protective

pollutant limits for the use or disposal of sewage sludge. However,

where numerical pollutant limits are not feasible, EPA may adopt design

or operational standards. EPA has done both for incinerated sewage

sludge. EPA established pollutant limits that restrict the level of

certain pollutants in the sewage sludge to ensure that pollutants in

emissions from a sewage sludge incinerator will not exceed safe levels.

In the case of organic pollutants, EPA established an operational

standard for total hydrocarbons (THC) in the emissions rather than

limits on organic pollutants in the sewage sludge fed to the

incinerator.

Subpart E establishes these requirements for the firing of sewage

sludge: (1) A general requirement in Sec. 503.42, (2) compliance with

the National Emission Standards for Hazardous Air Pollutants (NESHAPs)

for beryllium and mercury (Sec. 503.43); (3) sewage sludge pollutant

limits for lead, arsenic, cadmium, chromium and nickel (Sec. 503.43);

(4) an operational standard for total hydrocarbons (THC) in the stack

emissions (Sec. 503.44); (5) management practices (Sec. 503.45); and

(6) frequency of monitoring, recordkeeping, and reporting requirements

(Sec. 503.46-503.48).

Under the regulation, as discussed in more detail below, site-

specific variables are used to determine the specific requirements for

an individual sewage sludge incinerator. These variables include the

type of incinerator, type of air pollution control device(s) (APCD),

incinerator combustion temperature, dispersion factor, incinerator

control efficiency, and incinerator stack height. Thus, for example,

allowable pollutant concentrations in the sewage sludge will vary

depending on dispersion of the emissions from the incinerator stack.

This, in turn, is a function of meteorological conditions around the

incinerator site as well as the height of the incinerator exit gas

stack.

Under current 40 CFR 503.43, the pollutant limits for all sewage

sludge incinerators depend on actual site-specific conditions rather

than default values or standard factors that necessarily overgeneralize

sewage sludge incinerator site conditions. Thus, the regulation

provides flexibility to tailor pollutant limits for individual sewage

sludge incinerators based on actual conditions at the incinerator. (For

example, the allowable lead concentration in incinerated sewage sludge

depends on a dispersion factor. However, the dispersion factor must be

determined from an air dispersion model which in turn requires site-

specific data.) As a result, while the current regulation describes

what the standard is and how it is determined, the actual requirements

are not detailed in the regulation. Instead, the regulation calls for

determination of site-specific factors in accordance with instructions

from the permitting authority (e.g., section 503.43(a)(2)(i), ``when *

* * specified by the permitting authority * * *'').

The current regulation also requires continuous emission monitoring

of certain incinerator operating conditions to ensure compliance with

the part 503 requirements. Again, the sewage sludge incinerator

requirements in current 40 CFR 503.45 call for the permitting authority

to ``specify'' the criteria for installation, calibration, operation,

and maintenance of the instruments used to measure and record these

conditions (e.g., combustion temperature). Other current management

practices require the permitting authority to ``specify'' maximum

combustion temperature and values for the operating parameters for the

sewage sludge incinerator air pollution control device(s), which also

may vary from sewage sludge incinerator to sewage sludge incinerator.

Finally, current subpart E requires the permitting authority to specify

the frequency of monitoring for beryllium and mercury and for the

operating parameters for the air pollution control devices.

In summary, the subpart E part 503 requirements provide for

consideration of site-specific factors by directing the permitting

authority to specify parameters required to determine applicable

requirements. The result of this site-by-site tailoring of incinerator

requirements is that the determination of an individual incinerator's

applicable requirements are deferred until the permitting authority's

decision. Put another way, the regulation already contains a provision

requiring that incinerators meet the specific requirements, but until

the permitting authority specifies the underlying site-specific factors

for the individual sewage sludge incinerator, compliance or non-

compliance with the requirements cannot be determined. This approach is

different from the other sewage sludge use or disposal requirements in

part 503, which are designed to be self-implementing.

B. Description of Current Regulation and Proposed Amendments

1. Site-specific Exemption From Frequency of Monitoring, Recordkeeping,

and Reporting Requirements in Incineration Subpart

a. Current Regulation

Section 503.43 establishes pollutant limits for metals in sewage

sludge that is incinerated. As discussed further below, these pollutant

limits vary for each incinerator based on site-specific factors (e.g.,

location, control efficiency).

Since publication of the part 503 regulation, EPA has reviewed

information on the pollutant limits, determined as prescribed in

Sec. 503.43, for a number of different sewage sludge incinerators. In

many cases, the pollutant limits are considerably higher--often several

orders of magnitude--than the actual concentration of metals in the

sewage sludge being incinerated. This indicates that the incinerator

operating conditions and site conditions will permit safe incineration

of sewage sludge with high

[[Page 54777]]

concentration of pollutants. Given the resulting ample margin of safety

between the calculated pollutant limit and the actual concentrations of

metals in incinerated sewage sludge, EPA is considering introducing

additional flexibility into the incinerator requirements.

b. Proposed Amendment

To reduce the burden of compliance with the part 503 requirements,

EPA is proposing to amend the applicability section (Sec. 503.40) of

the incineration subpart to not subject an incinerator to a pollutant

limit and the associated frequency of monitoring, recordkeeping, and

reporting requirements for the pollutant in certain circumstances, if

approved by the permitting authority. Under the approach proposed

today, the sewage sludge would not have to be monitored for a

particular pollutant and records of the concentration of a pollutant in

sewage sludge would not have to be kept if the calculated pollutant

limit exceeds the highest average daily concentration for that

pollutant in the sewage sludge for the months in the previous calendar

year.

The proposed approach assumes that the incinerator continues to be

operated as it was operated during its performance test. If it is not

operated in that manner, the permitting authority may reimpose the

frequency of monitoring, recordkeeping, and reporting requirements for

the particular pollutant.

EPA requests comments on the proposed site-specific exemption from

the frequency of monitoring, recordkeeping and reporting requirements

for sewage sludge incinerators. EPA also requests comments on other

approaches that should be considered.

For example, should the Agency limit the exemption to circumstances

in which the calculated pollutant limit is significantly higher than

the average daily concentration of the pollutant in the incinerated

sewage sludge? If so, how should the Agency define significantly

higher? An order of magnitude higher than the actual concentration in

the sewage sludge, 50 percent higher, or some other percentage?

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

a. Current Regulation

40 CFR 503.43 establishes limits on the allowable ``daily

concentration'' of arsenic, cadmium, chromium, lead and nickel in

sewage sludge that is incinerated. 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. For all five regulated metals, the regulation requires

determination of the following two factors that are dependent on site-

specific conditions. These 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 pollutants 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,

if authorized by the permitting authority, the regulation provides for

the calculation of an alternative allowable chromium limit based on a

site-specific measurement of the fraction of hexavalent chromium to

total chromium in an incinerator's stack emissions. The preamble to the

final part 503 regulation explains in more detail at 58 FR 9355,

February 19, 1993, how allowable concentrations are determined. EPA did

not rely on assumed values for dispersion factors and control

efficiency because the Agency concluded that use of such values would

overgeneralize site conditions and establish more restrictive

conditions than dictated by protection of public health and the

environment (see 58 FR at 9355).

b. Proposed Amendment

The proposal would revise 40 CFR 503.43(c)(1) and (d)(1) to clarify

that the sewage sludge must meet the average daily concentration for a

pollutant based on the number of days in a month that the incinerator

operates. This clarification is consistent with EPA's risk assessment

for incinerators, which was based on average daily values. (See the

definition of risk specific concentration (RSC) in Sec. 503.41(i),

which is used in the calculation of the allowable average daily sewage

sludge concentration.)

The proposal also would revise 40 CFR 503.43(c)(2), (c)(3), (d)(4),

and (d)(5) to remove the requirement for the permitting authority to

prescribe the air dispersion model used in determining the DF, and the

performance test to determine CE. In addition, the proposal would

delete the requirement in current Sec. 503(d)(3) that requires the

permitting authority to authorize an allowable chromium limit based on

site-specific hexavalent chromium stack emissions.

EPA is proposing these changes to modify the regulation to make it

self-implementing and thus reduce the burden on the regulated community

as well as the Agency's own limited permitting resources. In the

current form, the regulation requires that the permitting authority

determine appropriate models and performance tests parameters before

pollutant limits can be calculated. This approach assumed a process in

which the person who fires sewage sludge in a sewage sludge incinerator

worked closely with a permitting authority in deciding what models and

performance test procedures would be appropriate.

Recognizing that such a process can be very resource-intensive, EPA

is today proposing a different approach. Under this approach, allowable

pollutant limits must be calculated using the equation provided in the

regulation. To establish these limits, the dispersion factor must be

determined through an air dispersion model and the incinerator control

efficiencies must be determined through a performance test of the

incinerator. The choice of appropriate models and the specifications

for the performance tests rests with the person who fires sewage sludge

in a sewage sludge incinerator. These choices will, of course, be

reviewed by the permitting authority. Sewage sludge incinerators should

retain all records that show how allowable pollutant limits were

calculated.

Proposed new Sec. 503.43(e)(1) describes the factors that should be

considered in selecting an air dispersion model. The air dispersion

model must be appropriate for the geographical, physical, and

population conditions at the sewage sludge incinerator site. Its

selection must be consistent with good air pollution control practices

for minimizing air emissions. New dispersion modeling to establish the

DF is required where, as provided in proposed 40 CFR 503.43(e)(4),

geographic or physical conditions at the incinerator site warrant.

Under proposed 40 CFR 503.43(e)(2), a person who fires sewage

sludge in a sewage sludge incinerator must submit a proposed air

dispersion modeling protocol to the permitting authority no later than

30 days from the date of publication of a final rule promulgating such

an amendment. This will provide the permitting authority the

opportunity to review the submitted protocol to insure that it

accurately models conditions at the incinerator site. The permitting

authority must notify the operator within 30 days if the selected model

may not be used to determine the DF because it is inappropriate. If the

person who fires sewage sludge does not hear from the permitting

authority to the

[[Page 54778]]

contrary, that person may use the submitted protocol to calculate its

DF.

EPA has published several guidance documents that contain

recommendations as to how to select appropriate air dispersion models.

These models take into account such site-specific factors as stack

height, stack diameter, stack gas temperature, exit velocity, and

surrounding terrain. See U.S. EPA, ``Guideline on Air Quality Models

(Revised)'' (EPA-450/2-78-027R) (July 1993). This information also is

available in Appendix W to 40 CFR Part 51. See also U.S. EPA,

``Technical Support Document for Sewage Sludge Incineration'' at

Section 5.6.1 (EPA 822/R-93-003) (November 1992).

In many cases, the appropriate air dispersion factor can be

determined using the ISCLT2 air dispersion model. The ISCLT2 model is a

steady-state Gaussian plume model that can be used to assess pollutant

emissions from a wide variety of sources including sewage sludge

incinerators in the long-term mode. It is appropriate for both rural or

urban areas, and either flat or rolling terrain whenever the terrain

elevation is lower than the stack height. The model can account for the

following factors: settling and dry deposition of particles; downwash;

area, line and volume sources; plume rise as a function of downwind

distance; separation of point sources (multiple stacks); and limited

terrain adjustment. If ground level terrain in the impact area exceeds

the stack height, complex and intermediate terrain modeling also must

be addressed.

As noted, this proposed rulemaking also would revise Sec. 503.43

(c)(3) and (d)(5) to delete the requirement that the permitting

authority specify how to determine the CE. Proposed Sec. 503.43 (c)(3)

and (d)(5) provide, instead, that the CE for equation (4) and equation

(5), respectively, shall be determined from a performance test of the

sewage sludge incinerator. Proposed paragraph (e)(1) of Sec. 503.43

requires that the performance test be appropriate for the type of

sewage sludge incinerator and that the test be conducted in a manner

consistent with good air pollution control practices for minimizing air

emissions. The performance test measures the degree to which the sewage

sludge incinerator and associated air pollution control devices remove

a given pollutant. As discussed below, performance tests also are

required because they generate data on which to base the parameter

operating ranges for the incinerator.

Proposed paragraph (e)(3) also specifies procedures to be followed

in conducting performance tests of sewage sludge incinerators. These

procedures parallel those in 40 CFR 60.8, a regulation that describes

the general procedures for conducting performance testing under the

Clean Air Act. EPA believes that it is necessary to specify minimal

procedures for conducting performance testing now that subpart E of

part 503 is self-implementing.

Proposed 40 CFR 503.43(e)(3) would require performance testing

under representative incinerator operating conditions for metals

emissions, with the highest expected feed rate of sewage sludge within

design specifications. Further, the permitting authority must be

notified at least 30 days prior to the test so the permitting authority

may observe the test. Each performance test must consist of at least

three separate runs at the same operating conditions. For the purpose

of establishing a control efficiency for a pollutant, the arithmetic

mean of the results of the three runs should be used.

EPA has prepared guidance on the performance test used to develop

the incinerator control efficiency for a pollutant. Section 5.6.2 and

appendix E of the ``Technical Support Document for Sewage Sludge

Incineration'' (EPA 822/R-93-003) (November 1992) discuss performance

testing to derive the control efficiency for the five metals limited

for sewage sludge incinerators under part 503 (arsenic, cadmium,

chromium, lead, and nickel). EPA also published guidance on performance

testing in the September, 1994 draft version of the ``Guidance for

Writing Permits for the Use or Disposal of Sewage Sludge.''

As noted, this proposed rulemaking would delete the requirement in

current Sec. 503.43(d)(3) for the permitting authority authorization of

a site-specific chromium risk specific concentration (RSC) used in the

equation (5) calculation. Either the national default RSC or the RSC

calculated using equation (6) can be used in equation (5) to develop a

pollutant limit for chromium.

EPA has developed a methodology for determining hexavalent chromium

emissions from stationary sources. See U.S. EPA, ``Laboratory and Field

Evaluations of a Methodology for Determining Hexavalent Chromium

Emissions from Stationary Sources'' (EPA/600/3-91/052) (1992). Persons

who choose to calculate RSC values for chromium using equation (6) must

use a scientifically defensible methodology for determining hexavalent

chromium emissions.

EPA also proposes to make a technical change to Sec. 503.43(c)(3)

to correct the number of the referenced equation to (4). In addition,

EPA proposes to make three technical changes to Sec. 503.43(d) (1) and

(2). These changes will correct two typographical errors in the

definition of terms in (d)(1) and in the reference to Equation ``6'' in

(d)(2).

Given the proposed deadlines for complying with this regulation,

EPA would encourage incinerators that do not have a permit to begin the

effort to determine the pollutant limits for the incinerator. Prior to

the effective date of this regulation, if EPA has been notified about

the model used to determine the DF and if EPA was notified 30 days in

advance of a performance test, following promulgation, the information

on the DF model will not have to be resubmitted and a second

performance test will not have to be conducted. However, in the event

that conditions and circumstances change significantly at the

incinerator after the allowable pollutant limits are calculated, the

requirements in today's proposed rule will apply when the final

regulation becomes effective.

The control efficiency of a sewage sludge incinerator is derived

from a comparison of the mass of a pollutant in the sewage sludge fed

to the incinerator to the mass of the pollutant in the exit gas from

the incinerator stack. Thus, to determine the control efficiency,

representative samples of the sewage sludge fed to the incinerator and

the exit gas from the incinerator stack have to be collected and

analyzed for the pollutants in 40 CFR 503.43. Under Sec. 503.8(b)(4),

EPA requires the use of a specific test methodology for analyzing the

metals concentrations in the sewage sludge fed to the incinerator:

``Test Methods for Evaluating Solid Waste, Physical/Chemical Methods,''

EPA Publication SW-846, Second Edition (1982) with Updates I (April

1984) and II (April 1985) and Third Edition (November 1986) with

Revision I (December 1987).

EPA does not currently require the use of a specific test

methodology for calculating the metals emissions in exit gases from

sewage sludge incinerator stacks. EPA does require, however, the use of

a specific methodology for the determination of metals emissions

(chromium, cadmium, arsenic, lead, and zinc) in exhaust gases from

hazardous waste incinerators and other similar combustion processes as

part of the Methods Manual for Compliance with the BIF Regulations in

40 CFR part 266, appendix IX. (The method also is available in ``EPA

Methods Manual for Compliance with the BIF Regulations'' (EPA 530-SW-

91-010).) Under the Clean Air Act, EPA has proposed to add

[[Page 54779]]

method 29, ``Determination of Metals Emissions from Stationary

Sources,'' to appendix A of part 60, and to propose amendments to

method 101A of appendix B of part 61. (59 FR 48259, September 20,

1994). Method 29 is being proposed so that it can be used to determine

mercury, cadmium, and lead emissions from municipal waste combusters

under subpart Ea of part 60. (Method 29 is already applicable to

arsenic, chromium, and nickel.) Public comment is specifically

requested on the propriety of requiring use of one of these methods

(assuming the air method is finalized as proposed) to analyze emissions

from sewage sludge incinerator stacks for the metals regulated under

Sec. 503.43(c) and (d).

3. Management Practices

a. Current Regulation

i. Specification for Instruments

40 CFR 503.45 contains seven management practices for incineration

of sewage sludge. These include requirements to install four

instruments to measure and record data to determine compliance with the

THC operational standard. Key operating parameters for sewage sludge

incinerators are monitored continuously to indicate that adequate

combustion conditions are maintained in the incinerator (consistent

with the conducted performance test) and to minimize metal and THC

emissions. The regulation requires that the four monitoring instruments

be installed, calibrated, operated, and maintained, as specified by the

permitting authority.

40 CFR 503.44 contains an operational standard for the total

hydrocarbons (THC) concentration in the exit gas from a sewage sludge

incinerator. By controlling THC, EPA controls the emission of organic

pollutants in the sewage sludge fed to the incinerator and created

during the incineration process. Under Sec. 503.44(c), the monthly

average concentration for total hydrocarbons in the sewage sludge

incinerator exit gas may not exceed 100 parts per million on a

volumetric basis, when corrected for zero-percent moisture and to

seven-percent oxygen using equations (7) and (8) of Sec. 503.44.

As revised in February 1994, 40 CFR 503.40(c) provides the option

of continuous monitoring of the carbon monoxide concentration in the

exit gas in lieu of continuous monitoring of the THC concentration in

the exit gas if specified conditions are met. See 59 FR 9095, February

25, 1994. As discussed at 59 FR 9098, the alternative of monitoring for

carbon monoxide is effective pending changes after an EPA study of the

matter. At the completion of the study, which EPA contemplates will

address monitoring for carbon monoxide or other parameters (including

temperature) to measure compliance with the THC operational standard in

lieu of monitoring THC continuously, EPA will decide whether further

amendments to part 503 are needed.

Under 40 CFR 503.45, an instrument must be installed, calibrated,

operated, and maintained, as specified by the permitting authority,

that continuously measures and records the following information: the

total hydrocarbon concentration in the exit gas, the oxygen

concentration in the exit gas, and information to determine the

moisture content in the exit gas; and the combustion temperatures in

the sewage sludge incinerator. By continuously measuring the oxygen

content and information needed to determine moisture content of the

exit gas, the THC emission value can be corrected to seven-percent

oxygen and for zero-percent moisture.

Where incinerators have monitors that automatically correct for

moisture content (e.g., continuous CO monitors), a correction for

moisture content need not be made. In addition, CO and THC monitors and

measuring devices may be shared if there is more than one sewage sludge

incinerator at the treatment works.

ii. Specification of Maximum Combustion Temperature

40 CFR 503.45(e) requires the permitting authority to specify the

maximum combustion temperature for a sewage sludge incinerator based on

information obtained from the performance test of the sewage sludge

incinerator. This practice ensures that the maximum combustion

temperature does not significantly exceed the combustion temperature

during the performance test of the incinerator.

iii. Specification of Air Pollution Control Device Operating Parameters

Another management practice for sewage sludge incineration, which

is described in Sec. 503.45(f), requires that an air pollution control

device be operated within the values for the operating parameters

specified by the permitting authority and that those values be based on

information obtained during the performance test of the sewage sludge

incinerator. The regulation contemplates that sewage sludge

incinerators will have limits and monitoring requirements for selected

parameters that are consistent with the performance of air pollution

control devices. Examples of air pollution control devices include

venturi scrubbers, impingement scrubbers, mist eliminators, dry

scrubbers, fabric filters, and wet electrostatic precipitators. For

example, pressure drop, liquid flow rate, gas temperature, and gas flow

rate are recommended parameters for assessing performance for venturi

scrubbers.

b. Proposed Regulation

This proposed rulemaking would revise 40 CFR 503.45 (a)(1) and (b)-

(d) to delete the requirement for the permitting authority to specify

the manner in which the described instruments are to be installed,

calibrated, operated, and maintained. Under proposed Sec. 503.45(h)(1),

the person who fires sewage sludge in a sewage sludge incinerator must

select the instruments described in Sec. 503.45 (a)(1) and (b)-(d) that

are appropriate for the type of sewage sludge incinerator and the

instruments must be installed, calibrated, operated, and maintained

consistent with good air pollution control practice for minimizing

emissions.

In the final part 503 rule, EPA required the permitting authority

to specify the manner in which these instruments were to be installed,

calibrated, operated, and maintained because, at that time, there was

only limited EPA guidance in this area. In June 1994, however, EPA

published new guidance entitled ``THC Continuous Emission Monitoring

Guidance for Part 503 Sewage Sludge Incinerators'' (EPA 833-B-94-003).

The guidance contains recommended installation, calibration, operation,

and maintenance procedures for the instruments specified in

Sec. 503.45(a)-(c). With regard to the instrument required under

Sec. 503.45(d) for continuous measurement of combustion temperatures,

see the ``Technical Support Document for Sewage Sludge Incineration''

at section 7.4 (EPA 822/R-93-003).

EPA is today also proposing to delete the current requirement 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 in current Sec. 503.45

(e) and (f). Both sections already provide that the specified values

are to be based on information obtained during the performance test of

the sewage sludge incinerator.

Proposed Sec. 503.45(e) states that the operation of the sewage

sludge incinerator shall not significantly

[[Page 54780]]

exceed the maximum combustion temperature for the sewage sludge

incinerator and that the maximum combustion temperature for the sewage

sludge incinerator shall be based on information obtained during the

performance test of the sewage sludge incinerator. EPA recognizes the

variability during operation of a sewage sludge incinerator and intends

that the maximum temperature be an average temperature. EPA requests

comment on the type of averaging and on a range above the maximum seen

in the performance test that should be allowed.

Proposed Sec. 503.45(f) states that the operation of the sewage

sludge incinerator shall not cause the values for the operating

parameters for the sewage sludge incinerator air pollution control

device to be exceeded. Proposed Sec. 503.45(f) also requires that the

air pollution control device selected be appropriate for the particular

sewage sludge incinerator; that the operating parameters for the air

pollution control device indicate adequate performance of the device;

and that the values for the operating parameters for the sewage sludge

incinerator air pollution control devices be based on results of the

performance test of the sewage sludge incinerator. No changes should be

made in the values for the air pollution control device operating

parameters after the performance test. EPA intends that the values for

the operating parameters for the sewage sludge incinerator air

pollution control devices be a range. EPA requests comment on

appropriate ranges around those seen in the performance test that

should be allowed for each parameter.

EPA has developed guidance describing common air pollution control

devices, the parameters for various air pollution control device

technologies that indicate adequate performance of the device, and the

common measuring devices for the respective parameters. See the

``Technical Support Document for Sewage Sludge Incineration'' sections

2.3, 7.5, and appendix M (EPA 822/R-93-003).

As noted above, EPA has developed guidance describing recommended

parameters for various air pollution control device technologies that

indicate adequate performance of the device. EPA is considering whether

it is appropriate to standardize, by regulation, which parameters can

be used to indicate adequate performance for a particular air pollution

control device. EPA would appreciate receiving comments concerning

whether such a regulation is necessary and whether the parameters that

are listed in appendix M to the ``Technical Support Document for Sewage

Sludge Incineration,'' as cited above, for each air pollution control

device continue to be appropriate. If developed, such a regulation

could allow flexibility in the selection of alternative parameters,

unless the permitting authority specifies otherwise.

4. Frequency of Monitoring

a. Current Regulation

i. Beryllium, Mercury, and Operating Parameters for Air Pollution

Control Devices

40 CFR 503.43 (a) and (b) provide that the firing of sewage sludge

in a sewage sludge incinerator may not violate the National Emission

Standard for Hazardous Air Pollutant (NESHAP) for beryllium in subpart

C and for mercury in subpart E of 40 CFR part 61, if applicable. To

support this pollutant limit, 40 CFR 503.46(a) requires monitoring for

mercury and beryllium as specified by the permitting authority.

The NESHAP in 40 CFR 61.32(a) establishes an emission standard for

beryllium of no more than 10 grams of beryllium emitted over a 24-hour

period; or, alternatively, upon the approval of the Administrator, 40

CFR 61.32(b) establishes an ambient concentration limit for beryllium

in the vicinity of the stationary source of 0.01 g/m\3\,

averaged over a 30-day period. To comply with Sec. 61.32(a), Sec. 61.33

imposes a one-time start-up stack sampling requirement for beryllium

emissions. If the option of compliance with Sec. 61.32(b) is chosen,

Sec. 61.34 requires the stationary source to locate air sampling sites

in accordance with a plan approved by the Administrator and to operate

monitoring sites continuously.

With regard to mercury, the NESHAP in 40 CFR 61.52(b) establishes

an emission standard of 3200 grams of mercury per 24-hour period.

Sections 61.53(d) and 61.54 establish two alternatives means of

establishing compliance with the emission standard: (1) an emissions

test or (2) a sewage sludge sampling test. If the incinerator chooses

sewage sludge sampling, Sec. 61.54 requires the sewage sludge to be

sampled according to method 105 in appendix B to part 61 and includes

an equation to determine the mercury emissions from the sewage sludge

sampling results:

[GRAPHIC][TIFF OMITTED]TP25OC95.000

EHg=Mercury emissions, g/day.

M=Mercury concentration of sewage sludge on a dry solids basis,

g/g.

Q=Sewage sludge charging rate, Kg/day.

Fsm=Weight fraction of solids in the collected sewage sludge after

mixing.

1000=Conversion factor, Kg g/g2.

Sections 61.53(d) and 61.54 impose a one-time start-up sampling

requirement. Section 61.55 imposes an annual monitoring requirement for

incinerators for which mercury emissions exceed 1,600 grams per 24-hour

period, demonstrated either by stack sampling according to Sec. 61.53

or sewage sludge sampling according to Sec. 61.54.

Part 503 also imposes a monitoring obligation for sewage sludge

incinerator air pollution control device operating parameters. Current

40 CFR 503.46(c) requires monitoring for these parameters as specified

by the permitting authority.

ii. Total Hydrocarbons, Oxygen Concentration, and Information To

Determine Moisture Content

Section 503.46(b) requires that the total hydrocarbons (THC)

concentration and oxygen concentration in the exit gas from a sewage

sludge incinerator stack and information used to determine moisture

content in the exit gas be monitored continuously. Oxygen content and

information used to determine moisture content have to be measured

continuously because that information is needed to correct the measured

exit gas THC concentrations to seven percent oxygen and for zero

percent moisture.

Sections 503.45 (a) and (b) require that a continuous emissions

monitor (CEM) for THC and oxygen, respectively, be installed,

calibrated, operated, and maintained. As mentioned previously, today's

proposal deletes the requirement for the permitting authority to

specify how to install, calibrate, operate, and maintain these CEMs.

b. Proposed Regulation

This proposed rulemaking would incorporate the monitoring

frequencies for beryllium and mercury now contained in 40 CFR Part 61

and establish specific monitoring frequencies for the sewage sludge air

pollution control device operating parameters. With regard to

monitoring for beryllium and mercury, EPA proposes to revise current 40

CFR 503.46(a)(1), which requires the permitting authority to specify

monitoring frequencies for beryllium and mercury, to provide that

beryllium shall be monitored as required under subpart C of 40 CFR part

61 and mercury as required under subpart E of 40 CFR part 61. For

beryllium, this represents a one-time start-up stack

[[Page 54781]]

sampling requirement or, alternatively, a continuous air sampling

requirement. For mercury, this represents a one-time start-up stack or

sewage sludge sampling requirement, with annual monitoring for those

sources for which mercury emissions exceed 1600 grams per 24-hour

period, as specified in 40 CFR 61.53-.55. Because this monitoring is

already required under the air program, the proposed regulation would

not impose an additional monitoring burden on the regulated community.

EPA requests comments concerning whether it is appropriate to

establish a periodic monitoring frequency for beryllium and mercury for

sewage sludge incinerators. In contrast to the Clean Air Act, EPA has

historically required periodic monitoring to determine compliance with

Clean Water Act requirements.

For mercury, some options that EPA is considering are:

1. A periodic (quarterly or annual) stack or sewage sludge sampling

requirement, depending on whether the incinerator has selected the

emissions or sewage sludge sampling alternative specified in 40 CFR

61.53(d) or 61.54. The sampling obligation could apply to all sewage

sludge incinerators that emit mercury, and could be conducted according

to the test methods specified in the NESHAP (method 101A in appendix B

to part 61 for stack sampling or method 105 in appendix B to part 61

for sewage sludge sampling). One disadvantage with this approach is the

cost of conducting stack sampling for metals emissions, which can be in

the range of several thousand dollars per sampling event. In contrast,

the cost of sampling sewage sludge for most metals, including mercury,

is normally less than $80 per sample. Sewage sludge sampling would not

impose any additional burden because part 503 already requires sewage

sludge sampling of other metals.

2. A periodic (monthly or quarterly or annual) requirement to

sample sewage sludge for mercury. The difference between options 1 and

2 is that all sewage sludge incinerators would monitor the sewage

sludge for mercury, even those incinerators that choose to conduct

stack sampling to meet the NESHAP requirements. All sewage sludge

incinerators may use the equation specified in Sec. 61.54(d) to assess

whether the mercury concentration measured in the sewage sludge meets

the NESHAP emission standard. EPA also requests comments concerning the

use of the Sec. 61.54 equation for purposes of part 503 sewage sludge

sampling for beryllium. The advantage of this option is that the cost

of NESHAPs sampling sewage sludge is reduced to a minimal analytic cost

alone, as discussed above.

3. Periodic sewage sludge monitoring based on the amount of sewage

sludge fed to the sewage sludge incinerator. Option 3 represents a

variation on Option 2. Option 3 would require sewage sludge sampling

for all incinerators, as above. The frequency of monitoring, however,

would vary for particular sewage sludge incinerators based on annual

amount of sewage sludge fired in an incinerator as it does for other

pollutants. This could be accomplished by revising current 40 CFR

503.46(a)(2) to add mercury as a pollutant for which monitoring can be

conducted according to the requirements of Table 1 of Sec. 503.46.

Table 1 currently establishes a range of monitoring frequencies from

once per year to once per month, depending on the amount of sewage

sludge fired in a sewage sludge incinerator (metric tons per 365-day

period) for the pollutants arsenic, cadmium, chromium, lead and nickel.

Current Sec. 503.46(a)(3) also allows the permitting authority to

reduce the frequency of monitoring to a minimum of once per year after

the sewage sludge has been monitored for two years at the frequency

stated in Table 1. [See discussion above in section III.B on a proposed

amendment to allow the permitting authority to reduce the frequency of

monitoring for each use or disposal practice to less than once a year

after the sewage sludge has been monitored for two years.] EPA also

could include mercury on the list of pollutants for which the

permitting authority may decrease the frequency of monitoring. This

approach to monitoring for mercury appears to be simple to implement

and relatively inexpensive. As is the case for the pollutants currently

monitored according to Table 1, it links frequency of monitoring to

amount of sewage sludge fired in an incinerator, which would decrease

monitoring obligations and related costs for smaller sewage sludge

incinerators.

For beryllium, EPA may consider imposing a periodic stack sampling

obligation (such as annual monitoring), for those few incinerators that

must comply with the emission standard specified in 40 CFR 61.32(a).

(There is no need to impose a periodic monitoring obligation for those

incinerators that conduct air sampling under 40 CFR 61.32(b). Section

61.34 requires continuous operation of monitoring sites.) Again, the

disadvantage of conducting stack sampling is the cost, which can range

to several thousand dollars per sampling event. As discussed above, the

sampling of sewage sludge for a metal such as beryllium is much lower

in cost. However, such sampling is not an option that is available

under the beryllium NESHAP. EPA would appreciate receiving comments

concerning whether it is appropriate and feasible to develop a

conversion factor so that, for purposes of part 503, results of

sampling sewage sludge for beryllium can be compared to the emission

standard.

Proposed Sec. 503.46(c) requires that the air pollution control

device operating parameters be monitored daily. EPA believes that the

burden on the regulated community to meet a daily monitoring obligation

is minimal. To insure the proper operation of the sewage sludge

incinerator, due to the variable characteristics of the sewage sludge

fed to the incinerator, the operating parameters for the applicable air

pollution control operating devices are monitored on at least a daily

(if not hourly or continuous) basis. EPA envisions that, among other

acceptable approaches, this monitoring obligation, where the monitoring

is not conducted on a continuous basis, could be met by recording the

values for the operating parameters for the air pollution control

devices in a daily log book. Retention of this logbook would fulfill

the recordkeeping obligations of 40 CFR 503.47(g) and the logbook

records could form the basis for the annual report to be submitted

under Sec. 503.48.

Other frequencies of monitoring that EPA considered for this

management practice are: (1) Monitoring as appropriate for the air

pollution control device and (2) monitoring per manufacturer's

instructions for the air pollution control device. It appears likely,

however, that in many instances these options would result in the same

monitoring frequency or the monitoring obligation might be greater than

a daily monitoring obligation. EPA sees no need for reason to impose a

greater than daily minimum monitoring obligation.

The Agency is proposing to amend section 503.46(b) to allow the

permitting authority to specify an alternative to continuous monitoring

of the exit gas from a sewage sludge incinerator for THC, oxygen, and

information needed to determine moisture content. In some cases,

continuous monitoring may not be necessary to show compliance with the

THC operational standard of 100 parts per million on a volumetric

basis. EPA is considering two options for determining when the

monitoring frequency may be reduced. Both of these options assume that

the emissions will be monitored for THC periodically, but not

continuously.

[[Page 54782]]

The first option bases the frequency of monitoring for THC, oxygen,

and information used to determine moisture content on the amount of

sewage sludge fired in a sewage incinerator annually. For example, if

the amount fired is 25 metric tons per year or less, the permitting

authority could require periodic monitoring for THC, oxygen, and

information to determine moisture content and then require that the

incinerator be operated consistent with the way it was operated during

the monitoring episode. The monitoring frequency for oxygen and

information used to measure moisture content should be consistent with

the monitoring frequency for THC because the oxygen concentration and

moisture content information are used to adjust the measured THC

values. This approach is similar to the current part 503 frequency of

monitoring approach for pollutants in the incineration subpart, which

is based on the amount of sewage sludge fired in a sewage sludge

incinerator annually. The lower the amount of sewage sludge fired, the

less frequent samples of sewage sludge have to be collected and

analyzed for pollutants.

The second option for determining whether to reduce the frequency

of monitoring for THC is the number of days in a year that the

incinerator operates. For example, if the incinerator operates less

than 100 days per year, the frequency for THC monitoring may be

something less than continuously. This is similar to Option 1 in that

the more days an incinerator operates, the more sewage sludge is

expected to be fired in the incinerator.

EPA specifically solicits public comment on the question of what is

the appropriate monitoring frequency for beryllium, mercury, and the

operating parameters for air pollution control devices. EPA also is

requesting comments on the proposal to monitor THC, oxygen content, and

information needed to determine moisture content less than

continuously. Should less than continuous monitoring be allowed for

those parameters?

EPA also is requesting comments on the above options to determine

when less than continuous monitoring for THC (also oxygen and

information needed to determine moisture content) should be allowed.

Should less than continuous monitoring be allowed when the amount of

sewage sludge incinerated annually or the number of days the

incinerator operates during the year is below a certain value? Or,

should some other parameter be used to decide whether the frequency can

be reduced? If it is based on the amount of sewage sludge fired

annually or number of days the incinerator operates during the year,

what should be the amount or number of days below which less than

continuous monitoring will be allowed?

In addition, should less than continuous monitoring be allowed if

carbon monoxide (CO) is monitored in the exit gas in lieu of monitoring

THC? A part 503 amendment published in the Federal Register on February

24, 1994 (59 FR 9095) allows CO to be monitored in lieu of monitoring

THC in certain situations.

5. Reporting and Recordkeeping Obligations

This proposed rulemaking does not change the current recordkeeping

and reporting requirements in 40 CFR 503.47 and 503.48. The information

retained under Sec. 503.47 and reported under Sec. 503.48 would

continue to form the basis for permitting authority oversight,

including enforcement, of subpart E requirements.

6. Compliance Deadlines

a. Current Regulation

Current 40 CFR 503.2 establishes the deadlines for compliance with

the requirements of part 503. Paragraph (a) provides that compliance

with all standards must be achieved as expeditiously as practicable,

but no later than February 19, 1994. Where compliance with the

standards requires construction of new pollution control facilities,

compliance with the standards must be achieved as expeditiously as

practicable, but no later than February 19, 1995.

Paragraphs (b) and (c) establish the deadlines for compliance with

the frequency of monitoring, recordkeeping, and reporting requirements

under part 503. Paragraph (b) provides that the THC operational

standard is effective on February 19, 1994, or, if compliance with the

operational standard for THC requires the construction of new pollution

control facilities, by February 19, 1995. Paragraph (c) provides that

all other requirements for frequency of monitoring, recordkeeping, and

reporting imposed under part 503 were effective on July 20, 1993.

b. Proposed Regulation

EPA proposes to require compliance with the new requirements of

subpart E of part 503 as expeditiously as practicable, but no later

than 90 days from the publication date of the final rule. When new

pollution control facilities must be constructed to comply with the

revised requirements for sewage sludge incineration in subpart E,

compliance shall be achieved as expeditiously as practicable, but no

later than 12 months from the date of publication of the final rule.

The compliance deadline in proposed Sec. 503.2(d) only applies where

the permitting authority has not already specified requirements for the

incinerator. EPA requests comment on the compliance deadlines.

V. Proposed Amendment to Part 403

EPA is today proposing to amend 40 CFR part 403, Appendix G--

Section II (Additional Pollutants Eligible for Removal Credits). EPA is

proposing to amend the General Pretreatment Regulations so that a

removal credit may be authorized for chromium in sewage sludge that is

land applied, given compliance with other regulatory requirements, as

long as the chromium concentration in the sewage sludge does not exceed

12,000 mg/kg.

Many industrial facilities discharge large amounts of pollutants to

POTWs where their wastewaters mix with wastewater from other sources,

domestic sewage from private residences and run-off from various

sources prior to treatment and discharge by the POTW. The introduction

of pollutants to a POTW from industrial discharges may pose several

problems. These include potential interference with the POTW's

operation or pass-through of pollutants if inadequately treated.

Congress, in section 307(b) of the Act, directed EPA to establish

pretreatment standards to prevent these potential problems. Congress

also recognized that, in certain instances, POTWs could provide some or

all of the treatment of an industrial user's wastewater that would be

required pursuant to the pretreatment standard. Consequently, Congress

established a discretionary program for POTWs to grant `` removal

credits'' to their indirect dischargers. The credit, in the form of a

less stringent pretreatment standard, allows an increased concentration

of a pollutant in the flow from the indirect discharger to the POTW.

Section 307(b) of the CWA establishes a three-part test a POTW

would need to meet to obtain removal credit authority for a given

pollutant. A removal credit may be authorized only if (1) the POTW

``removes all or any part of such toxic pollutant,'' (2) the POTW's

ultimate discharge would ``not violate that effluent limitation, or

standard which would be applicable to that toxic pollutant if it were

discharged'' directly rather than through a POTW and (3) the POTW's

discharge would ``not prevent sludge use and disposal by such [POTW] in

accordance with section [405]. * * *'' Section 307(b).

[[Page 54783]]

The United States Court of Appeals for the Third Circuit has

interpreted the statute to require EPA to promulgate comprehensive

sewage sludge regulations before any removal credits could be

authorized. NRDC v. EPA, 790 F.2d 289, 292 (3rd Cir. 1986) cert.

denied. 479 U.S. 1084 (1987). Congress made this explicit in the Water

Quality Act of 1987, which indicated that EPA could not authorize any

removal credits until it issued the sewage sludge use or disposal

regulation required by section 405(d)(2)(a)(ii). EPA has promulgated

removal credit regulations that are codified at 40 CFR part 403.7.

At the same time EPA promulgated the part 503 regulation, EPA

amended its General Pretreatment Regulations to add a new Appendix G

that includes two tables of pollutants that would be eligible for a

removal credit so long as the other procedural and substantive

requirements of 40 CFR part 503 and 40 CFR 403.7 are met. The first

table (Appendix G--Section I) lists, by use or disposal practice, the

pollutants that are regulated in part 503 and eligible for a removal

credit. The second table (Appendix G--Section II) lists, by use or

disposal practice, additional pollutants that are eligible for a

removal credit if the concentration of the pollutant does not exceed a

prescribed concentration. The pollutants in Appendix G--Section II are

the pollutants that EPA evaluated and decided not to regulate during

development of the part 503 regulation. See 58 FR at 9381-5. EPA

included chromium in Appendix G--Section I because the Agency

established pollutant limits in the Part 503 regulation for sewage

sludge that is land applied, surface disposed, or incinerated.

In the final part 503 regulation, EPA limited the chromium content

of land-applied sewage sludge to prevent possible plant injury. On

November 15, 1994, the D.C. Circuit remanded the chromium pollutant

limits for modification or additional justification, concluding that

EPA lacked an adequate evidentiary basis for its risk-based chromium

limit. Leather Industries of America, Inc. v. Environmental Protection

Agency, 40 F.3d 392 (D.C. Cir. 1994). Elsewhere in today's Federal

Register, in response to the remand, EPA is promulgating a final rule

that deletes chromium from the pollutants that are regulated when

sewage sludge is applied to the land. EPA has concluded that there is

no current basis for establishing chromium limits in land-applied

sewage sludge. EPA's decision not to regulate chromium in land-applied

sewage sludge is based on its reevaluation of the Agency's land

application risk assessment for chromium developed during the part 503

rulemaking. This reassessment showed that chromium is unlikely to be

present in sewage sludge in concentrations that present a risk to

public health or the environment.1

\1\For the Part 503 regulation, in descending order of

stringency, the risk assessment cumulative loading rates for

chromium are 3,000 kg/hectare (Pathway 8--plant toxicity), 5,000 kg/

hectare (Pathway 11--tractor operator) and 12,000 kg/hectare

(Pathway 14--groundwater). See Technical Support Document for the

Land Application of Sewage Sludge Table 5.4-5, p. 5-435. Having

determined that current information would not support regulation of

chromium to prevent plant injury, EPA took a second look at Pathways

11 and 14. EPA revised the Pathway 11 analysis and determined that a

significantly less stringent cumulative pollutant loading rate than

5,000 kg/hectare would protect a tractor operator from potential

injury from inhaled chromium. A complete explanation of EPA's

reanalysis may be found in the docket for this rulemaking.

Given the fact that the Pathway 11 and Pathway 14 risk limits

(expressed as a chromium concentration in sewage sludge) exceeded

the 99th percentile sludge concentration by at least an order of

magnitude, EPA decided not to establish land application pollutant

limits for chromium.

---------------------------------------------------------------------------

At the same time EPA deleted chromium limits from its part 503 land

application requirements, EPA took two other actions. First, the Agency

removed chromium from the list of regulated pollutants for land

application in Appendix G--Section I for which a removal credit is

available. Second, to ensure the continued eligibility of chromium for

a removal credit, EPA added a footnote in Appendix G--Section II

stating the chromium concentration in Section II for land application

would be determined on a case-by-case basis. Case-by-case

determinations would continue to be made until EPA determines a safe

concentration for chromium in sewage sludge that is land applied--the

action being proposed here.

In the 1993 amendments to part 403, EPA included pollutants that it

evaluated for risk and decided not to regulate in Appendix G--Section

II at the highest concentration evaluated as safe based on the

concentrations developed during the risk assessment for the final part

503 regulation. See 58 FR 9382. Consequently, EPA reviewed its land

application risk assessment to determine the safe level for chromium.

Based on the results of the 1993 risk assessment and the results of the

revaluation of Pathway 11, EPA is proposing to include a number for

land-applied chromium in Appendix G--Section II at a concentration of

12,000 mg/kg. EPA has concluded that this is the highest level EPA

identified as safe for the following reasons.

As explained above, EPA reevaluated its 1993 land application risk

assessment for Pathway 11 and determined that a cumulative pollutant

loading rate for chromium for land-applied sewage sludge well in excess

of the 5,000 kg/hectare loading rate calculated in the 1993 assessment

presents little threat to a tractor operator because of the low

hexavalent chromium concentration in the sewage sludge. Consequently,

the next pathway in EPA's land application risk assessment at which

chromium may present a threat to public health and the environment is

Pathway 14, the ground-water pathway. (Technical Support Document for

the Land Application of Sewage Sludge, November 1992, Table 5.4-5, p.

5-435). The 1993 risk assessment concluded that as long as the total

amount of chromium applied to the land in sewage sludge did not exceed

12,000 kg/hectare, the potential for adverse affects on the ground

water beneath a land application site is low. EPA is asking for public

comment on whether a concentration of 12,000 mg/kg2 is the

appropriate level at which chromium should be included on Appendix G--

Section II.

\2\In the case of those pollutants EPA evaluated in the 1993

risk assessment and decided not to regulate, EPA established Section

II pollutant concentrations that are derived from the 1993 risk

assessment cumulative pollutant loading rates. To convert a

cumulative pollutant loading rate to a pollutant concentration, EPA

assumed that 10 metric tons of sewage sludge would be applied to a

hectare of land each year for 100 years.

---------------------------------------------------------------------------

VI. Regulatory Requirements

A. Executive Order 12866

Under Executive Order 12866 (58 FR 51735, October 4, 1993), the

Agency must determine whether the 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 governments 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

[[Page 54784]]

President's priorities, or the principles set forth in the Executive

Order.''

Executive Order 12866 requires EPA to prepare an assessment of the

costs and benefits of any ``significant regulatory action.'' It has

been determined that this 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, costs to the regulated community should be

reduced or at least remain unchanged. OMB has waived review of this

proposed rule.

B. Executive Order 12875

Under Executive Order 12875 (58 FR 58093, October 28, 1993),

entitled Enhancing the Intergovernmental Partnership, the Agency is

required to develop an effective process to permit elected officials

and other representatives of State, local, and tribal governments to

provide meaningful and timely input in the development of regulatory

proposals.

EPA sought the involvement of those persons who are intended to

benefit from or expected to be burdened by this proposal before issuing

a notice of proposed rulemaking. Following informal consultation, in

January 1995, EPA circulated a draft of the proposed changes for

comment to the regulated community, environmentalists, and States. EPA

received a small number of comments, which have been addressed in

today's rule.

C. Regulatory Flexibility Act

Pursuant to the Regulatory Flexibility Act, 5 U.S.C. 601-612,

whenever an agency is required to publish a General Notice of

Rulemaking for any proposed or final rule, it must prepare and make

available for public comment a regulatory flexibility analysis that

describes the impact of the rule on small entities (i.e., small

businesses, small organizations, and small governmental jurisdictions).

No regulatory flexibility analysis is required, however, if the head of

the Agency certifies that the rule will not have a significant impact

on a substantial number of small entities.

This action to amend the part 403 and part 503 regulations proposed

today provides added flexibility and technical clarification for some

of the requirements. It will only provide beneficial opportunities for

entities that may be affected by the rule. Accordingly, I certify that

this regulation will not have a significant economic impact on a

substantial number of small entities. This regulation, therefore, does

not require a regulatory flexibility analysis.

D. Paperwork Reduction Act

The information collection requirements for part 503 were approved

by OMB under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. (See

58 FR 9377, February 19, 1993.) There are no new reporting,

notification, or recordkeeping (information) provisions in this

proposed rule.

E. Unfunded Mandates

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), P.L.

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, or tribal governments, in

the aggregate, or to the private sector, of $100 million or more in any

one year. When such a statement is needed for an EPA rule, 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, giving them meaningful and

timely input in the development of EPA regulatory proposals with

significant Federal intergovernmental mandates, and informing,

educating, and advising them on compliance with the regulatory

requirements.

EPA has determined that today's amendments to part 503 do not

contain a Federal mandate that may result in expenditures of $100

million or more for State, local or tribal governments or the private

sector in any one year. With one exception, the proposed amendments

either clarify existing regulatory requirements or provide additional

flexibility to the regulated community in complying with current

regulatory requirements.

[[Page 54785]]

For example, EPA is proposing a number of changes to reduce the

reporting and recordkeeping burden of the current requirements. These

would include amendments to authorize the permitting authority to

reduce the required frequency of monitoring of sewage sludge or, in the

case of incinerated sewage sludge, to exempt certain facilities

entirely from monitoring, recordkeeping, and reporting requirements.

EPA also is proposing to amend the current regulation to delete the

requirement for land appliers of sewage sludge to record the time of

day sewage sludge is applied. In addition, the proposal would modify

the certification provision of the current substantive requirement to

certify certain information to the permitting authority. Under the

proposal, the certifier would certify to the accuracy of the submitted

information and not, as is the case at present, to the submitter's

compliance with regulatory requirements.

EPA is proposing to delete language from the current regulation

that required the permitting authority to specify certain factors used

to calculate site-by-site pollutant limits for sewage sludge

incinerators and to specify how to install, calibrate, operate and

maintain incinerator continuous emission monitors. The proposal also

includes technical amendments that would correct inaccurate cross-

references and add omitted reporting dates and inadvertently omitted

phrases. Therefore, to the extent that the proposed regulation would

reduce the costs of complying with current part 503 requirements, the

proposed changes will lessen the regulatory burden on State, local, or

tribal governments.

One proposed change may result in a small annual increase in costs

to State, local, or tribal governments in certain circumstances. The

current regulation provides that sewage sludge that is applied to land

for a beneficial purpose or disposed at surface disposal sites must,

among other conditions, meet requirements for reducing the pathogen

content of the sewage sludge. Sewage sludge must meet either Class A or

Class B pathogen requirements. The regulation provides a number of

alternatives for achieving the Class A and Class B requirements. These

alternatives include treatment processes that reduce the density of

enteric viruses, viable helminth ova and Salmonella, sp. bacteria in

the sewage sludge. In addition, in the case of the Class A

alternatives, the density of either fecal coliform or Salmonella sp.

bacteria in the sewage sludge may not exceed prescribed levels at the

time the sewage sludge is used or disposed. Today's proposal would

change the description of one of the Processes to Further Reduce

Pathogens to require that a certain dose of gamma rays be used. The

dosage was inadvertently deleted from the process description in the

final rule.

As noted above, there are either no (or reduced) costs associated

with the other changes proposed today. Thus, today's proposed rule is

not subject to the requirements in sections 202 and 205 of the Act.

EPA has determined that this proposal contains no regulatory

requirements that might significantly or uniquely affect small

governments that may operate publicly owned treatment works (POTWs)

generating sewage sludge. The proposed amendments would not

significantly affect small governments because as explained above, the

proposed amendments would either provide additional flexibility in

complying with pre-existing regulatory requirements or clarify these

requirements. The proposed amendments also would not uniquely affect

small governments because the increased flexibility provided by the

proposed changes would be available to POTWs operated by small

governments to the same extent as to other sewage sludge users or

disposers.

List of Subjects

40 CFR Part 403

Environmental protection, Incineration, Land application,

Pollutants, Removal Credits, Sewage sludge, and Surface disposal.

40 CFR Part 503

Environmental Protection, Frequency of monitoring, Incineration,

Incorporation by reference, Land application, Management practices,

Pathogens, Pollutants, Reporting and recordkeeping requirements, Sewage

sludge, Surface disposal and Vector attraction reduction.

Dated: October 10, 1995.

Carol M. Browner,

Administrator.

For the reasons set out in the preamble, title 40 of the Code of

Federal Regulations is proposed to be amended as set forth below:

PART 403--GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW

SOURCES OF POLLUTION

1. The authority citation for 40 CFR part 403 continues to read as

follows:

Authority: Sec. 54(c)(2) of the Clean Water of 1977, (Pub. L.

95-217) sections 204(b)(1)(C), 208(b)(2)(C)(iii), 301(b)(1)(A)(ii),

301(b)(2)(A)(ii), 301(b)(2)(C), 301(h)(5), 301(i)(2), 304(e),

304(g), 307, 308, 309, 402(b), 405, and 501(a) of the Federal Water

Pollution Control Act (Pub. L. 92-500) as amended by the Clean Water

Act of 1977 and the Water Quality Act of 1987 (Pub. L. 100-4).

2. Appendix G to part 403 is proposed to be amended by revising

section ``II.'' to read as follows:

Appendix G--Pollutants Eligible for A Removal Credit

I. * * *

[[Page 54786]]

II. Additional Pollutants Eligible for a Removal Credit

[Milligrams per kilogram--dry weight basis]

----------------------------------------------------------------------------------------------------------------

Use or disposal practice (SD)

Pollutant ----------------------------------------------

LA Unlined\1\ Lined\2\ I

----------------------------------------------------------------------------------------------------------------

Arsenic.......................................................... ......... ........... \3\100 ........

Aldrin/Dieldrin (Total).......................................... 2.7 ........... ........... ........

Benzene.......................................................... \3\16.0 140 3,400 ........

Benzo(a)pyrene................................................... 15.0 \3\100 \3\100 ........

Bis(2-ethylhexyl)phthalate....................................... ......... \3\100 \3\100 ........

Cadmium.......................................................... ......... \3\100 \3\100 ........

Chlordane........................................................ 86.0 \3\100 \3\100 ........

Chromium......................................................... 12,000.0 ........... \3\100 ........

Copper........................................................... ......... \3\46 \3\100 1,400.0

DDD, DDE, DDT (Total)............................................ 1.2 2,000 2,000 ........

2,4 Dichlorophenoxy-acetic acid.................................. ......... 7 7 ........

Fluoride......................................................... 730.0 ........... ........... ........

Heptachlor....................................................... 7.4 ........... ........... ........

Hexachlorobenzene................................................ 29.0 ........... ........... ........

Hexachlorobutadiene.............................................. 600.0 ........... ........... ........

Iron............................................................. \3\78.0 ........... ........... ........

Lead............................................................. ......... \3\100 \3\100 ........

Lindane.......................................................... 84.0 \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................................................ 30.0 ........... ........... ........

Phenol........................................................... ......... 82 82 ........

Polychlorinated biphenyls........................................ 4.6 60Cobalt and

137Cesium, at dosages of at least 1.0 megarad at room

temperature (ca. 20 deg. C).

[FR Doc. 95-25776 Filed 10-24-95; 8:45 am]

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