[Federal Register Volume 59, Number 38 (Friday, February 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-4372]


[[Page Unknown]]

[Federal Register: February 25, 1994]


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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 503

[FRL-4842-8]

 

Standards for the Use or Disposal of Sewage Sludge

AGENCY: U.S. Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: On November 25, 1992, pursuant to section 405 of the Clean 
Water Act (CWA), EPA promulgated a regulation to protect public health 
and the environment from reasonably anticipated adverse effects of 
certain pollutants in sewage sludge (February 19, 1993). This 
regulation established requirements for the final use or disposal of 
sewage sludge when: (1) The sludge is applied to the land either to 
condition the soil or to fertilize crops grown in the soil; (2) the 
sludge is disposed on land by placing it in surface disposal sites; and 
(3) the sludge is incinerated. Today's action amends this regulation 
with respect to two aspects of the rule pending EPA's reconsideration 
of certain issues. The issues under reevaluation concern the 
appropriate pollutant limits for molybdenum in sewage sludge when land 
applied and the requirement for certain sewage sludge incinerators to 
monitor incinerator emissions continuously for total hydrocarbons 
(THC).

EFFECTIVE DATE: February 19, 1994.

FOR FURTHER INFORMATION CONTACT: Alan Hais, Chief, Sludge Risk 
Assessment Branch, Health and Ecological Criteria Division (4304), 
Office of Science and Technology, U.S. Environmental Protection Agency, 
401 M Street, SW., Washington, DC 20460, telephone (202) 260-5389.

SUPPLEMENTARY INFORMATION:

A. Authority

    Today's rule is being promulgated under the authority of section 
405 of the Clean Water Act (CWA). Section 405(d) requires EPA to 
establish management practices and numerical limits adequate to protect 
public health and the environment against reasonably anticipated 
adverse effects of toxic pollutants in sewage sludge. Section 405(e) 
prohibits any person from disposing of sludge from a publicly-owned 
treatment works or other treatment works treating domestic sewage 
except in compliance with the section 405 regulations.

B. Amendment of Pollutant Limits for Molybdenum When Land Applied

    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 (40 CFR part 503) published in 
the Federal Register on February 19, 1993 (58 FR 9248). This regulation 
establishes requirements for the final use or disposal of sewage sludge 
that are codified at 40 CFR part 503. By letter dated May 25, 1993, 
Climax Metals Company filed a petition with the Agency asking that EPA 
reconsider the molybdenum pollutant limits for sewage sludge when it is 
applied to the land and to stay the February 19, 1994, compliance date 
for these pollutant limits pending reconsideration. Subsequently, on 
June 25, 1993, Climax Metals Company, American Mining Congress, The 
Chem-Met Company, Eastern Technologies, Inc., Gulf Coast Chemical, 
Jamestown Chemical Company, Inc., Midland Research Labs, Inc., and 
North Metals and Chemical Company, generators or users of molybdenum, 
filed a petition with the United States Court of Appeals for the 10th 
Circuit seeking review of the land application pollutant limits for 
molybdenum in the part 503 Rule. This petition for review was 
subsequently transferred to the D.C. Circuit.
    The molybdenum cumulative pollutant loading rate (CPLR) promulgated 
at Table 2 of Sec. 503.13 in the final part 503 rule is 18 kg of 
molybdenum per hectare of land. The CPLR was determined from Pathway 6 
of the land application risk assessment. Pathway 6 evaluates the amount 
of a pollutant in sewage sludge that is protective of livestock and 
wild animals that consume plants grown on sludge-amended soil. In the 
case of molybdenum, the CPLR is designed to protect cattle from 
molybdenosis. The major concern that Climax and others have brought to 
the Agency's attention is related to the studies used to assess 
exposure conditions and the exposure assumptions for the establishment 
of the molybdenum CPLR for land application of sewage sludge. In 
particular, Climax and others questioned the use of the data from the 
Pierzynski and Jacobs (1986) study to determine the crop uptake slope 
used in the Pathway 6 risk assessment. These interested parties state 
that this approach results in an overprotective molybdenum limit 
because the sludges used in the study were highly contaminated with 
molybdenum (1500 mg molybdenum per kg of sewage sludge, while sewage 
sludge usually contains 40 mg/kg) and because the Pierzynski and Jacobs 
data were inappropriately weighted with data from only one other study 
(Soon and Bates, 1985).
    EPA has reviewed Climax's request and has evaluated additional data 
and additional information submitted by Climax supporting a different 
crop uptake slope for molybdenum. Based on this preliminary evaluation, 
EPA is amending part 503 to delete the molybdenum pollutant limits in 
Tables 2, 3, and 4 of Sec. 503.13 pending its reconsideration of 
appropriate molybdenum pollutant limits. EPA's preliminary review of 
the data indicates the appropriateness of reevaluation of the 
cumulative pollutant loading rate for molybdenum established in Table 2 
of Sec. 503.13 of the February 19, 1993 rule. Because the molybdenum 
cumulative pollutant loading rate is used to develop the molybdenum 
pollutant concentration limit and annual pollutant loading rate in 
Tables 3 and 4 of Sec. 503.13, respectively, EPA is also amending these 
tables to remove the molybdenum pollutant limits.
    As noted, the molybdenum limits in Tables 2, 3 and 4 were 
determined from a risk assessment of Pathway 6 and are designed to 
protect animals consuming feed crops grown on sludge-amended soil from 
molybdenosis. Specifically, EPA, using a mathematical algorithm, 
calculated what quantity of molybdenum in sewage sludge per hectare of 
land could be added to the soil without resulting in exceeding the 
threshold in crops fed to domesticated animals that is associated with 
molybdenosis. That calculation is dependent on three variables. These 
are the threshold level of molybdenum in feed crops associated with 
molybdenosis, the background level of molybdenum in feed crops and the 
relationship between molybdenum added to the soil from sewage sludge 
and the resulting level in feed crops.
    EPA has reviewed the data it used to establish the molybdenum 
limits, information submitted by Climax and others and additional 
information the Agency has obtained. EPA has concluded that the 
molybdenum limits are highly sensitive to how the molybdenum data base 
used in the part 503 regulation was treated. An example illustrates why 
the data are sensitive to the method used in the calculation. Assume 
that two field studies are used to calculate the uptake of molybdenum 
by feed crops grown on sludge-amended soil. One study shows low 
molybdenum uptake levels while the second shows high uptake. If the 
study with low molybdenum uptake levels includes only three data points 
while the study showing high uptake contains 20 data points, 
calculation of a single uptake value from the studies will differ 
depending on how the data points in the individual studies are treated. 
If all data points are weighted equally, then the results will be most 
heavily influenced by the high uptake data points. Contrarily, if the 
results are averaged for each study separately and then the studies, 
rather than data points, weighted equally, the influence of the high 
uptake data is mitigated.
    Given the limited number of studies relied upon for the part 503 
molybdenum limits and the resulting sensitivity of the results to the 
method adopted for weighting data points in those studies, EPA 
determined that it should reconsider these limits. A preliminary review 
of additional field studies suggests that use of data from sewage 
sludge that is highly contaminated by molybdenum may yield results that 
could overpredict crop uptake and background molybdenum levels in feed 
crops at the lower levels of molybdenum required by part 503. This 
leads the Agency to conclude that the limits adopted in Tables 2, 3, 
and 4 may be more restrictive than required to protect public health 
and the environment because of both an inappropriately high background 
molybdenum level in feed crops and molybdenum uptake rate. This 
information has led the Agency to conclude that it should reevaluate 
its determination of the molybdenum pollutant limits for land 
application of sewage sludge.
    EPA has concluded that amending its regulation to delete the 
current land application molybdenum pollutant limits pending 
reconsideration will not adversely affect public health and the 
environment for the following reasons. First, EPA is not modifying the 
ceiling concentration limit for molybdenum (75 milligrams per kilogram 
of sewage sludge on a dry weight basis) in Table 1 of Sec. 503.13. 
Sewage sludge that is land applied must have a molybdenum concentration 
equal to or less than this limit. Sewage sludge that exceeds this level 
cannot be land applied. Under a worst case scenario of 75 milligrams of 
molybdenum per kilogram of dry sewage sludge, if sewage sludge is 
applied at a rate of 10 metric tons of sewage sludge (dry weight basis) 
per hectare of land annually, it would take 24 years to reach the 
cumulative pollutant load of 18 kilograms per hectare for molybdenum--
the CPLR adopted in Table 2 of Sec. 503.13 in the final rule. Because 
EPA plans to propose and promulgate a new molybdenum cumulative 
pollutant loading rate in the near future, a new molybdenum pollutant 
concentration limit and a new annual pollutant loading rate (APLR), 
even if EPA concludes the same or lower limits are necessary to protect 
public health and the environment, the likelihood that the molybdenum 
in sewage sludge applied to the land during the time EPA reevaluates 
the molybdenum CPLR would harm public health and the environment is 
extremely low.
    Similarly, under this worst case scenario, sewage sludge sold or 
given away in a bag or other container for application to the land 
(e.g., for use on lawns or home gardens) is limited to an annual 
application rate of 12 dry metric tons per hectare. This application 
rate is calculated based on the ceiling concentration of 75 mg 
molybdenum per kg of dry sewage sludge and the annual pollutant loading 
rate of 0.9 kg per hectare per 365 day period listed in Table 4 of 
Sec. 503.13. Application rates above this amount would cause an 
exceedence of the molybdenum annual pollutant loading rate. However, 
the molybdenum pollutant limit on which the APLR is based is designed 
to protect animals consuming forage grown on sludge amended soils from 
molybdenum toxicity. The likelihood of cattle consuming feed crops 
grown on a lawn or home garden is small. In the multi-pathway risk 
assessment, the next most limiting pathway for molybdenum is Pathway 3, 
the ingestion of pure sewage sludge by a toddler. Pathway 3 is a more 
realistic concern for sewage sludge sold or given away in a bag or 
other container. The pollutant limit for this pathway is 400 milligrams 
of molybdenum per kilogram of dry sewage sludge, well above the ceiling 
concentration limit of 75 mg molybdenum per kg of dry sewage sludge. 
Because sewage sludge cannot be applied to the land if the molybdenum 
concentration is greater than 75 mg molybdenum per kg of dry sewage 
sludge, the toddler who may inadvertently ingest sewage sludge is 
protected during the time the Agency reconsiders the molybdenum 
pollutant limits. Therefore, today's amendments to the pollutant limits 
in Tables 2, 3, and 4 of Sec. 503.13 will not threaten public health or 
the environment for land application of either bulk sewage sludge sold 
or sewage sludge sold or given away in a bag or other container.

C. Modification of the Applicability of the Continuous Emission 
Monitoring Requirements for Total Hydrocarbons for Certain Incinerators

    On July 17, 1993, Gloucester County Utilities, Stony Brook Regional 
Sewerage Authority, Township of Wayne, Pequannock, Lincoln Park and 
Fairfield Sewerage Authority, Somerset Raritan Valley Sewerage 
Authority, Bayshore Regional Sewerage Authority, and the State of New 
Jersey filed a petition with the D.C. Circuit seeking review of the 
part 503 regulation. These petitioners challenged, among other things 
the failure of the part 503 regulation to allow site-specific sewage 
sludge incinerator emissions limits and the failure to allow State-
imposed emissions limitations, including monitoring and reporting 
requirements, to replace the part 503 requirements. The petitioners 
argue that the requirements to demonstrate compliance with a 100 ppm 
total hydrocarbon (THC) operational standard through continuous 
monitoring of THC emissions should be changed.
    Currently, the State of New Jersey requires that the exit gas from 
the petitioners' sewage sludge incinerators meet a 100 ppm carbon 
monoxide (CO) limit corrected for zero percent moisture and to seven 
percent oxygen. The State also requires the petitioners to monitor the 
exit gas continuously for CO. For these reasons, the petitioners asked 
for relief from the requirement to monitor THC continuously. To 
demonstrate compliance with the 100 ppm THC operational standard, the 
incinerator management practices in Sec. 503.45(a) require installation 
of a continuous equipment THC monitor. In the petitioners' view, 
installation of this instrument is not needed because any sewage sludge 
incinerator complying with State of New Jersey 100 ppm emissions 
limitation and continuous CO monitoring requirements will comply with 
the 100 ppm THC operational standard.
    EPA concluded that it is appropriate to reconsider its requirement 
for the continuous monitoring of THC in the case of certain 
incinerators. Based on a reassessment of information on THC emissions 
and CO emissions from certain types of sewage sludge incinerators, EPA 
has preliminary determined that incinerators that meet a 100 ppm CO 
emission limitation will easily achieve a 100 ppm THC operational 
standard. In these circumstances, EPA determined that requiring such 
incinerators to install and maintain continuous THC monitors was unduly 
burdensome and wasteful and would not result in increased environmental 
benefits. Accordingly, EPA finds there is good cause to amend its 
regulation, effective immediately, to authorize the demonstration of 
compliance with the 100 ppm THC operational standard by meeting a 100 
ppm CO limit and by monitoring the exit gas continuously for CO during 
the interim period of reconsideration. Therefore, EPA is today issuing 
a final rule amending the applicability provision of the part 503--
subpart E--Incineration to modify the applicability of certain 
management practices, frequency of monitoring requirements and 
recordkeeping requirements for sewage sludge incinerators meeting 
certain conditions.
    As a result of the amendment, the following requirements will not 
apply to sewage sludge incinerators meeting defined conditions: the 
management practice in Sec. 503.45(a); the frequency of monitoring 
requirements for THC concentration in Sec. 503.46(b); and the 
recordkeeping requirements for THC concentration in Sec. 503.47 (c) and 
(n). The management practice in 503.45(a) requires the installation of 
a continuous emissions monitor for total hydrocarbons. The monitoring 
requirements of Sec. 503.46(b) concern THC concentration in the exit 
gas. The recordkeeping requirements in Sec. 503.47 (c) and (n) deal 
with the total hydrocarbons concentration in the exit gas from the 
sewage sludge incinerator stack and with a calibration and maintenance 
log for THC concentration in the exit gas.
    The requirements outlined above do not apply to sewage sludge 
incinerators in the following circumstances. The sewage sludge 
incinerator must achieve a CO concentration in the exit gas of 100 ppm 
(monthly average) or lower, corrected for zero percent moisture and to 
seven percent oxygen. The incinerator owner/operator also must monitor 
the exit gas continuously for CO, keep records on the CO emissions, 
and, in certain cases, report the monthly average CO concentration 
annually to the permitting authority.
    EPA concluded there is good cause for taking today's action because 
current data support the petitioners' assertion that the THC 
concentration in the exit gas from the sewage sludge incinerators 
described above will comply with the 100 ppm (monthly average) THC 
operational standard in part 503 when the monthly average CO 
concentration in the exit gas is equal to or less than 100 ppm.

D. Procedural Requirements

    EPA has reviewed the two requests discussed above and concluded 
that: (1) The molybdenum CPLR, pollutant concentration limit, and APLR 
for land application should be reconsidered based on the new 
information, and (2) the THC operational standard in Sec. 503.44(c) 
will be achieved if a CO limit of 100 ppm is met. Accordingly, EPA is 
today taking final action amending its part 503 regulation. EPA's 
action amends the molybdenum pollutant limits for land application in 
Tables 2, 3, and 4 of Sec. 503.13 and the applicability of various part 
503 requirements related to THC in Sec. 503.45, Sec. 503.46, and 
Sec. 503.47 for certain incinerators until such time as the Agency has 
an opportunity to study these issues further. At the completion of the 
studies, EPA will decide whether to propose new molybdenum pollutant 
limits and whether further amendments to part 503 are needed concerning 
the monitoring of CO to demonstrate compliance with the THC operational 
standard in lieu of monitoring THC continuously.
    Section 553 of the Administrative Procedures Act provides that when 
an agency for good cause finds that notice and public procedure are 
impracticable, unnecessary or contrary to the public interest, it may 
first issue a rule without providing notice and comment. In addition, 
the agency may make the rule effective immediately. EPA has concluded 
here that it should both amend its part 503 regulation as described 
without providing for notice and comment and make these changes 
effective immediately.

1. Notice and Comment

    By today's action, the Agency avoids the possibility that some 
treatment works treating domestic sewage would be required to comply 
with certain numerical limits for molybdenum in sewage sludge that is 
land applied. The Agency has concluded at this juncture that these 
limits may be too stringent and consequently should be reconsidered. 
Given the pendency of the compliance deadline for the land application 
requirements, it would be impracticable to provide notice and comment. 
Further, the public interest would suffer to the extent that treatment 
works treating domestic sewage incurred increased costs associated with 
compliance with requirements that the Agency determines are not needed 
to protect public health and the environment. Given the retention of 
the ceiling limit on molybdenum in sewage sludge which may be applied 
to the land, EPA has concluded that public health and the environment 
will be adequately protected while the Agency is reconsidering what are 
the appropriate molybdenum limits for Tables 2, 3 and 4 of Sec. 503.13.
    Further, in the case of the amendments to the requirements for 
sewage sludge incinerators, the Agency has similarly concluded that 
notice and comment is impracticable and contrary to the public 
interest. EPA has concluded that the public interest will suffer if 
sewage sludge incinerators that achieve a 100 ppm CO level, as 
demonstrated by continuous CO monitoring, are also required to install 
THC monitors. Based on its evaluation, EPA has concluded that, if 
incinerators are meeting a 100 ppm CO level, the likelihood is 
substantial that such incinerators are well below the 100 ppm THC 
operational standard. Given this information and the fact that the 
obligation for many of these incinerators to achieve a 100 ppm or lower 
CO standard and monitor continuously antedated the promulgation of the 
100 ppm THC operational standard, EPA has concluded that the public 
interest does not support installation of THC monitors for such 
incinerators pending Agency reconsideration.

2. Effective Date

    Under section 405 of the CWA, EPA's sewage sludge regulation must 
require compliance with the regulation as expeditiously as practicable 
but in no case later than 12 months after its publication, unless such 
regulation requires construction of new pollution control facilities, 
in which case the regulation must require compliance expeditiously, but 
not later than two years from publication. The part 503 regulation was 
effective on March 22, 1993. In the case of the molybdenum pollutant 
limits and the continuous monitoring requirements for THC, the 
regulation required compliance by February 19, 1994. Because of the 
potential adverse effect on public interest noted above, the Agency has 
determined there is good cause for making this regulation effective 
immediately.

E. Regulatory Requirements

1. Executive Order 12866

    Executive Order 12866 requires EPA to prepare an assessment of the 
costs and benefits of any ``significant regulatory action.'' 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. 
Consequently, no assessment of costs and benefits is required.

2. 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 modify the part 503 regulation promulgated today is 
deregulatory in nature and thus 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.

3. Paperwork Reduction Act

    There are no reporting, notification, or recordkeeping 
(information) provisions in this rule. Such provisions, were they 
included, would be submitted for approval to the Office of Management 
and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et 
seq.

List of Subjects in 40 CFR Part 503

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

    Dated: February 18, 1994.
Carol M. Browner,
Administrator.
    For the reasons set out in the preamble, part 503 of title 40 of 
the Code of Federal Regulations is amended as set forth below:
    1. The authority citation for part 503 continues to read as 
follows:


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


    2. Section 503.13 is amended by revising paragraphs (b)(2), (b)(3), 
and (b)(4) to read as follows:


Sec. 503.13  Pollutant limits.

    (b) * * *
    (2) Cumulative pollutant loading rates. 

      Table 2 of Sec. 503.13.--Cumulative Pollutant Loading Rates       
------------------------------------------------------------------------
                                                              Cumulative
                                                              pollutant 
                                                               loading  
                         Pollutant                               rate   
                                                              (kilograms
                                                                 per    
                                                               hectare) 
------------------------------------------------------------------------
Arsenic....................................................           41
Cadmium....................................................           39
Chromium...................................................         3000
Copper.....................................................         1500
Lead.......................................................          300
Mercury....................................................           17
Nickel.....................................................          420
Selenium...................................................          100
Zinc.......................................................         2800
------------------------------------------------------------------------

    (3) Pollutant concentrations. 

           Table 3 of Sec. 503.13.--Pollutant Concentrations            
------------------------------------------------------------------------
                                                              Monthly   
                                                              average   
                       Pollutant                          concentrations
                                                            (milligrams 
                                                          per kilogram)1
------------------------------------------------------------------------
Arsenic.................................................             41 
Cadmium.................................................             39 
Chromium................................................           1200 
Copper..................................................           1500 
Lead....................................................            300 
Mercury.................................................             17 
Nickel..................................................            420 
Selenium................................................             36 
Zinc....................................................          2800  
------------------------------------------------------------------------
1Dry weight basis.                                                      

    (4) Annual pollutant loading rates. 

        Table 4 of Sec. 503.13.--Annual Pollutant Loading Rates         
------------------------------------------------------------------------
                                                               Annual   
                                                              pollutant 
                                                            loading rate
                         Pollutant                           (kilograms 
                                                             per hectare
                                                             per 365 day
                                                              period)   
------------------------------------------------------------------------
Arsenic...................................................          2.0 
Cadmium...................................................          1.9 
Chromium..................................................        150   
Copper....................................................         75   
Lead......................................................         15   
Mercury...................................................          0.85
Nickel....................................................         21   
Selenium..................................................          5.0 
Zinc......................................................        140   
------------------------------------------------------------------------

* * * * *
    5. Section 503.40 is amended by adding paragraph (c) to read as 
follows:


Sec. 503.40  Applicability.

* * * * *
    (c) The management practice in Sec. 503.45(a), the frequency of 
monitoring requirement for total hydrocarbon concentration in 
Sec. 503.46(b) and the recordkeeping requirements for total hydrocarbon 
concentration in Sec. 503.47(c) and (n) do not apply if the following 
conditions are met:
    (1) The exit gas from a sewage sludge incinerator stack is 
monitored continuously for carbon monoxide.
    (2) The monthly average concentration of carbon monoxide in the 
exit gas from a sewage sludge incinerator stack, corrected for zero 
percent moisture and to seven percent oxygen, does not exceed 100 parts 
per million on a volumetric basis.
    (3) The person who fires sewage sludge in a sewage sludge 
incinerator retains the following information for five years:
    (i) The carbon monoxide concentrations in the exit gas; and
    (ii) A calibration and maintenance log for the instrument used to 
measure the carbon monoxide concentration.
    (4) Class I sludge management facilities, POTWs (as defined in 40 
CFR 501.2) with a design flow rate equal to or greater than one million 
gallons per day, and POTWs that serve a population of 10,000 people or 
greater submit the monthly average carbon monoxide concentrations in 
the exit gas to the permitting authority on February 19 of each year.

[FR Doc. 94-4372 Filed 2-24-94; 8:45 am]
BILLING CODE 6560-50-P