Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Notices 3859 

2022.pdf. 

USEPA. 2022d. Learn about Cyanobacteria 

and Cyanotoxins. https://www.epa.gov/ 

cyanohabs/learn-about-cyanobacteriaand-cyanotoxins. Accessed September 8, 

2022. 

USEPA. 2022e. National Lakes Assessment 

2017 Web Report. https://www.epa.gov/ 

national-aquatic-resource-surveys/ 

reports-and-data-national-lakesassessment-2017. 

USEPA. 2022f. Restricted Use Product 

Summary Report (October 31, 2022). 

https://www.epa.gov/system/files/ 

documents/2022-11/RUP-Report-10-31- 

2022.pdf. 

USEPA. 2023a. Ethoprop. Updated 

Occupational and Non-Occupational 

Spray Drift Assessment for Registration 

Review. February 17, 2023, memo from 

Office of Chemical Safety and Pollution 

Prevention, Office of Pesticide Programs. 

https://www.regulations.gov/document/ 

EPA-HQ-OPP-2008-0560-0058. 

USEPA. 2023b. Entry for ‘‘Chronic Exposure’’ 

in the Integrated Risk Information 

System (IRIS) Glossary. https://

www.epa.gov/iris/iris-glossary. 

USEPA. 2023c. Pesticide Product and Label 

System Database. https://

ordspub.epa.gov/ords/pesticides/ 

f?p=PPLS:1. 

USEPA. 2023d. Pesticide Chemical Search 

for tebuconazole: https://

ordspub.epa.gov/ords/pesticides/ 

f?p=CHEMICALSEARCH:3::::21,

3,31,7,12,25:P3_XCHEMICAL_ID:3984. 

USEPA. 2024a. PFAS National Primary 

Drinking Water Regulation: Final Rule. 

Federal Register, 89(82): 32532, April 

26, 2024. https://www.govinfo.gov/ 

content/pkg/FR-2024-04-26/pdf/2024- 

07773.pdf. 

USEPA. 2024b. Regulatory Determination 5 

Support Document. EPA 815–B–24–017. 

USEPA. 2024c. Occurrence Data from the 

Fourth Unregulated Contaminant 

Monitoring Rule (UCMR 4). EPA 815–B– 

24–016. 

United States Geological Survey (USGS). 

2023. Estimated Annual Agricultural 

Pesticide Use. https://water.usgs.gov/ 

nawqa/pnsp/usage/maps/index.php. 

Last updated June 14, 2023. 

Water Quality Portal (WQP). 2023. Water 

Quality Portal Data Warehouse. https://

www.waterqualitydata.us/. Data 

Warehouse consulted September 2023. 

Weisburger, E.K., A.B. Russfield, F. 

Homburger, F., J.H. Weisburger, E. Boger, 

C.G. Van Dongen, and K.C. Chu. 1978.

Testing of Twenty-One Environmental

Aromatic Amines or Derivatives for

Long-Term Toxicity or Carcinogenicity.

Journal of Environmental Pathology and

Toxicology, 2(2): 325–356. https://

doi.org/10.1097/00043764-197911000-

00017.

WHO. 2011. Molybdenum in Drinking-Water. 

Background Document for Development 

of WHO Guidelines for Drinking-Water 

Quality. WHO/SDE/WSH/03.04/11/Rev/ 

1. https://cdn.who.int/media/docs/

default-source/wash-documents/washchemicals/molybdenum.pdf?sfvrsn=

d01920eb_4.

WHO. 2020a. Cyanobacterial Toxins: 

Cylindrospermopsins. Background 

Document for Development of WHO 

Guidelines for Drinking-Water Quality 

and Guidelines for Safe Recreational 

Water Environments. WHO/HEP/ECH/ 

WSH/2020.4. https://apps.who.int/iris/ 

bitstream/handle/10665/338063/WHOHEP-ECH-WSH-2020.4-eng.pdf. 

WHO. 2020b. Cyanobacterial Toxins: 

Microcystins. Background Document for 

Development of WHO Guidelines for 

Drinking-Water Quality and Guidelines 

for Safe Recreational Water 

Environments. WHO/HEP/ECH/WSH/ 

2020.6. 

https://cdn.who.int/media/docs/defaultsource/wash-documents/washchemicals/microcystins-background201223.pdf. 

WHO. 2021. Manganese in Drinking-Water. 

Background Document for Development 

of WHO Guidelines for Drinking-Water 

Quality. WHO/HEP/ECH/WSH/2021.5. 

https://iris.who.int/bitstream/handle/ 

10665/350933/WHO-HEP-ECH-WSH2021.5-eng.pdf. 

Wolansky, M.J., C. Gennings, K.M. Crofton. 

2006. Relative Potencies for Acute 

Effects of Pyrethroids on Motor Function 

in Rats. Toxicological Sciences, 89(1): 

271–277. https://doi.org/10.1093/toxsci/ 

kfj020. 

Wong, M.Y., S.D. Rathod, R. Marino, L. Li, 

R.W. Howarth, A. Alastuey, et al. 2021. 

Anthropogenic Perturbations to the 

Atmospheric Molybdenum Cycle. Global 

Biogeochemical Cycles, 35(2): 

e2020GB006787. https://doi.org/10.1029/ 

2020GB006787. 

Jane Nishida, 

Acting Administrator. 

[FR Doc. 2025–00133 Filed 1–14–25; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[EPA–HQ–OW–2024–0504; FRL 12451–01– 

OW] 

Draft Sewage Sludge Risk Assessment 

for Perfluorooctanoic Acid (PFOA) and 

Perfluorooctane Sulfonic Acid (PFOS) 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice of availability. 

SUMMARY: As part of the Environmental 

Protection Agency’s (EPA’s) 

commitment to safeguarding the 

environment from per- and 

polyfluoroalkyl substances (PFAS), the 

agency is announcing the availability of 

the ‘‘Draft Sewage Sludge Risk 

Assessment for Perfluorooctanoic Acid 

(PFOA) and Perfluorooctane Sulfonic 

Acid (PFOS)’’ for a 60-day public 

comment period. This draft risk 

assessment reflects the agency’s latest 

scientific understanding of the potential 

risks to human health and the 

environment posed by the presence of 

PFOA and PFOS in sewage sludge that 

is land applied as a soil conditioner or 

fertilizer (on agricultural, forested, and 

other lands), surface disposed, or 

incinerated. The draft risk assessment 

focuses on those living on or near 

impacted sites or those that rely 

primarily on their products (e.g., food 

crops, animal products, drinking water); 

the draft risk assessment does not model 

risks for the general public. This draft 

risk assessment underwent independent 

external peer review, and the EPA 

revised the document accordingly. Once 

finalized, the risk assessment will 

provide information on risk from use or 

disposal of sewage sludge and will 

inform the EPA’s potential future 

regulatory actions under the Clean 

Water Act (CWA). 

DATES: Comments must be received on 

or before March 17, 2025. 

ADDRESSES: The EPA has established a 

docket for the ‘‘Draft Sewage Sludge 

Risk Assessment for Perfluorooctanoic 

Acid (PFOA) and Perfluorooctane 

Sulfonic Acid (PFOS)’’ action under 

Docket ID No EPA–HQ–OW–2024–0504. 

You may send comments, identified by 

Docket ID No. EPA–HQ–OW–2024– 

0504, by any of the following methods: 

• Federal eRulemaking Portal:

https://www.regulations.gov/ (our 

preferred method). Follow the online 

instructions for submitting comments. 

• Mail: U.S. Environmental

Protection Agency, EPA Docket Center, 

Office of Water Docket, Mail Code 

28221T, 1200 Pennsylvania Avenue 

NW, Washington, DC 20460. 

• Hand Delivery or Courier: EPA

Docket Center, WJC West Building, 

Room 3334, 1301 Constitution Avenue 

NW, Washington, DC 20004. The Docket 

Center’s hours of operations are 8:30 

a.m. to 4:30 p.m., Monday through

Friday (except Federal Holidays).

Instructions: All submissions received 

must include the Docket ID No. for this 

rulemaking. Comments received may be 

posted without change to https://

www.regulations.gov/, including any 

personal information provided. For 

detailed instructions on sending 

comments and additional information 

on the rulemaking process, see the 

‘‘Public Participation—Written 

comments’’ heading of the 

SUPPLEMENTARY INFORMATION section of 

this document. 

FOR FURTHER INFORMATION CONTACT: 

David Tobias, Health and Ecological 

Criteria Division, Office of Science and 

Technology, Office of Water, 

Environmental Protection Agency; email 

address: biosolidsprogram@epa.gov. 


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3860 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Notices 

1An additional 1 percent of sewage sludge is 

disposed of using other management practices (e.g., 

deep-well injection). 

SUPPLEMENTARY INFORMATION: 

This notice of availability is organized 

as follows: 

I. Public Participation—Written Comments 

II. Background 

A. Clean Water Act Authorities 

B. What is the purpose of this action? 

C. What is sewage sludge? 

D. What are PFOA and PFOS? 

E. What are the potential sources of PFOA 

and PFOS to sewage sludge? 

F. What is a risk assessment? 

III. Description and Preliminary Findings of 

the EPA’s Draft Risk Assessment 

A. Scope of the Draft Risk Assessment 

B. Modeling Approaches 

C. Preliminary Findings of the Central 

Tendency Modeling 

IV. Next Steps 

A. Risk Reduction 

B. Related Actions 

C. Final Risk Assessment and Potential 

Future Actions 

I. Public Participation—Written 

Comments 

The EPA is seeking comments, 

particularly on scientific and technical 

issues, on its ‘‘Draft Sewage Sludge Risk 

Assessment for Perfluorooctanoic Acid 

(PFOA) and Perfluorooctane Sulfonic 

Acid (PFOS).’’ Submit your comments, 

identified by Docket ID No. EPA–HQ– 

OW–2024–0504, on the draft sewage 

sludge risk assessment at https://

www.regulations.gov (our preferred 

method), or the other methods 

identified in the ADDRESSES section. 

Once submitted, comments cannot be 

edited or removed from the docket. The 

EPA may publish any comment received 

to its public docket. Do not submit any 

information you consider to be 

Confidential Business Information (CBI) 

or other information whose disclosure is 

restricted by statute. Multimedia 

submissions (audio, video, etc.) must be 

accompanied by a written comment. 

The written comment is considered the 

official comment and should include 

discussion of all points you wish to 

make. The EPA will generally not 

consider comments or comment 

contents located outside of the primary 

submission (i.e., on the web, cloud, or 

other file sharing system). For the full 

EPA public comment policy, 

information about CBI or multimedia 

submissions, and general guidance on 

making effective comments, please visit 

https://www.epa.gov/dockets/ 

commenting-epa-dockets. 

II. Background 

A. Clean Water Act Authorities 

Consistent with CWA section 

405(d)(2), 33 U.S.C. 1345(d)(2), the EPA 

periodically reviews its existing 

regulations for the purpose of 

identifying additional toxic pollutants 

that may be present in sewage sludge 

and assesses whether those pollutants 

may adversely affect public health or 

the environment based on their toxicity, 

persistence, concentration, mobility, 

and potential for exposure. In December 

2022, the EPA completed its latest 

review of the sewage sludge regulations 

as published in the EPA’s Biennial 

Review of 40 CFR part 503 To Fulfill 

Clean Water Act Section 405(d)(2)(C), 

Biosolids Biennial Report No. 9 (see 

https://www.epa.gov/biosolids/biennialreport-no-9-reporting-period-2020- 

2021). This notice of availability for the 

draft risk assessment is in accordance 

with CWA section 405(g)(1), 33 U.S.C. 

1345(g)(1), which authorizes the EPA to 

conduct scientific studies and provide 

public information to promote the safe 

and beneficial management or use of 

sewage sludge. 

B. What is the purpose of this action? 

The purpose of this action is to 

request public comments, particularly 

regarding scientific and technical 

aspects, on the EPA’s ‘‘Draft Sewage 

Sludge Risk Assessment for 

Perfluorooctanoic Acid (PFOA) and 

Perfluorooctane Sulfonic Acid (PFOS).’’ 

The EPA is most interested in receiving 

comments regarding the draft risk 

assessment modeling (e.g., the 

scenarios, sewage sludge application 

rates, environmental fate and transport 

parameters, human exposure 

assumptions). The draft risk assessment 

reflects the agency’s latest scientific 

understanding of the risks to human 

health and the environment posed by 

the presence of PFOA and PFOS in 

sewage sludge that is land applied as a 

soil conditioner or fertilizer (on 

agricultural, forested, and other lands), 

surface disposed (e.g., placed in a 

sewage sludge-only landfill called a 

monofill), or incinerated. The draft risk 

assessment focuses on those living on or 

near impacted properties where sewage 

sludge has been used or disposed. The 

intent of the draft risk assessment is to 

evaluate whether there may be risks to 

human health or the environment for 

the wide range of possible sewage 

sludge use and disposal scenarios. Not 

all the scenarios described in the draft 

risk assessment may be common 

practice or applicable to the general 

public. The EPA uses sewage sludge risk 

assessments to help evaluate whether 

risk reduction actions, including 

regulation, are warranted to protect 

those who may experience elevated 

risks from sewage sludge use or 

disposal. The draft risk assessment 

reflects external peer review and 

incorporates revisions from the peer 

review process. The EPA will consider 

public comments and prepare a final 

risk assessment for publication. The 

EPA will announce the availability of 

the final risk assessment in the Federal 

Register. 

C. What is sewage sludge? 

When domestic sewage is transported 

and conveyed to a wastewater treatment 

plant (WWTP), it is treated to separate 

liquids from the solids, which produces 

a semi-solid, nutrient-rich product 

known as sewage sludge. In some 

instances, industrial wastewater is also 

conveyed to a WWTP and combined 

with domestic sewage. The terms 

‘‘biosolids’’ and ‘‘sewage sludge’’ are 

often used interchangeably by the 

public; however, the EPA typically uses 

the term ‘‘biosolids’’ to mean sewage 

sludge that has been treated to meet the 

requirements in the EPA’s regulation 

entitled, ‘‘Standards for the Use or 

Disposal of Sewage Sludge,’’ 

promulgated at 40 CFR part 503, and 

intended to be applied to land as a soil 

conditioner or fertilizer. In the U.S., 

there are generally three options for use 

or disposal of sewage sludge. Based on 

available data, (1) approximately 56 

percent of the nation’s sewage sludge is 

land applied as a soil conditioner or 

fertilizer (roughly 31 percent is applied 

to agricultural land and 25 percent is 

applied to other lands, such as 

reclamation sites, home lawns and 

gardens, or golf courses), (2) 

approximately 27 percent is disposed of 

in a sewage sludge monofill or 

municipal solid waste (MSW) landfill, 

and (3) approximately 16 percent is 

incinerated.1 Land application of 

sewage sludge can have environmental 

benefits including improved soil health, 

carbon sequestration, and reduced 

demand on non-renewable resources 

like phosphorus. Land application also 

generates reduced emissions of 

greenhouse gases compared to other 

management practices. 

D. What are PFOA and PFOS? 

PFOA and PFOS are two chemicals in 

a large class of synthetic chemicals 

called PFAS. PFOA and PFOS persist in 

the environment for long periods of time 

and have been linked to a variety of 

adverse human health effects. In 2024, 

the EPA classified both PFOA and PFOS 

as likely to be carcinogenic to humans 

and concluded that these chemicals are 

also likely to cause a range of noncancer effects in humans, including 

hepatic, immunological, cardiovascular, 

and developmental effects, depending 


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2The EPA acknowledges that the majority of food 

crops grown in the United States do not use sewage 

sludge as a soil conditioner or fertilizer and some 

states have restricted the land application of sewage 

sludge to food crops. However, this practice is not 

consistent across all states. Furthermore, because of 

the extreme persistence of PFOA and PFOS in soils, 

a property with previous sewage sludge land 

application that has been repurposed as a food or 

feed crop farm could still have multiple relevant 

human exposure pathways. 

on exposure conditions (see the EPA’s 

Final Human Health Toxicity 

Assessment for Perfluorooctanoic Acid 

(PFOA) and Related Salts, available at: 

https://www.epa.gov/sdwa/humanhealth-toxicity-assessmentperfluorooctanoic-acid-pfoa, and Final 

Human Health Toxicity Assessment for 

Perfluorooctane Sulfonic Acid (PFOS) 

and Related Salts, available at: https:// 

www.epa.gov/sdwa/human-healthtoxicity-assessment-perfluorooctanesulfonic-acid-pfos). 

PFAS have been manufactured and 

used by a broad range of industries 

since the 1940s, and there are estimated 

to be thousands of PFAS present in the 

global marketplace that are used in 

many consumer, commercial, and 

industrial products. PFOA and PFOS 

have been widely studied, and they 

were once high production volume 

chemicals within the PFAS chemical 

class. PFAS manufacturers voluntarily 

phased out domestic manufacturing of 

PFOS by 2002 and of PFOA by 2015, 

and the EPA restricted their uses by 

Significant New Use Rules (SNURs) 

issued under section 5(a)(2) of the Toxic 

Substances Control Act (TSCA), 15 

U.S.C. 2604(a)(2) (see https://

www.epa.gov/assessing-and-managingchemicals-under-tsca/risk-managementand-polyfluoroalkyl-substances-pfas). 

E. What are the potential sources of

PFOA and PFOS to sewage sludge?

Although domestic manufacturing of 

PFOA and PFOS have been phased out 

and their uses restricted, multiple 

activities still result in PFOA, PFOS, 

and their precursors being released to 

WWTPs. Current and historical 

activities include industrial releases 

(e.g., aqueous film-forming foam, pulp 

and paper plants), commercial releases 

(e.g., car washes, industrial launderers), 

and down-the-drain releases from 

homes (e.g., use of consumer products 

like after-market water resistant sprays, 

ski wax, floor finishes, and laundering 

of stain or water-resistant textiles with 

PFOA or PFOS coatings) (see the 

Preliminary Effluent Guidelines 

Program Plan 16, available at https://

www.epa.gov/eg/preliminary-effluentguidelines-program-plan, and the MultiIndustry Per- and Polyfluoroalkyl 

Substances (PFAS) Study—2021 

Preliminary Report, available at https:// 

www.epa.gov/system/files/documents/ 

2021-09/multi-industry-pfas-study_

preliminary-2021-report_508_

2021.09.08.pdf). If products containing 

PFOA or PFOS are disposed of at a lined 

MSW landfill, because the most 

common off-site management practice 

for landfill leachate is to transfer it to a 

WWTP, then that landfill’s leachate 

could be a source of PFOA and PFOS to 

a WWTP. At different WWTPs across 

the country, any of these release 

mechanisms may play a role in PFOA or 

PFOS entering the plant and 

contaminating the sewage sludge. 

Statewide surveys have found PFOA 

and PFOS in sewage sludge originating 

from industrial and non-industrial 

sources that are discharging to WWTPs. 

Traditional wastewater treatment 

technology does not remove or destroy 

PFOA or PFOS, and these chemicals 

typically accumulate in the sewage 

sludge. Appropriate pretreatment 

solutions at industrial dischargers exist, 

are cost-effective, and have been shown 

to be effective in reducing high 

concentrations of PFOA and PFOS; 

however, studies have found that PFOA 

and PFOS are consistently detected at 

varying levels in sewage sludge even at 

WWTPs that do not receive wastewater 

from industrial users of the chemicals 

(i.e., they only receive wastewater from 

residential and commercial users). 

F. What is a risk assessment?

Risk assessment is a scientific process

that is used to characterize the nature 

and magnitude of health risks to 

humans (i.e., children and adults) and 

ecological receptors (i.e., aquatic and 

terrestrial plants and wildlife) from 

pollutants (see https://www.epa.gov/ 

risk/about-risk-assessment#whatisrisk). 

An environmental risk assessment 

considers three primary factors: (1) 

presence (i.e., how much of a pollutant 

is present in the environment), (2) 

exposure (i.e., how much contact 

humans or wildlife have with the 

pollutant), and (3) the toxicity of the 

pollutant (i.e., the health effects the 

pollutant causes in humans or wildlife). 

The concentration of pollutants found 

in sewage sludge varies across space 

and time, depending on industrial and 

other inputs to individual WWTPs. The 

presence of a pollutant in sewage sludge 

alone does not necessarily mean that 

there is risk to human health or the 

environment from its use or disposal. 

The EPA estimates potential exposures 

to humans and environmental receptors 

by modeling the fate and transport of a 

pollutant through the environment, 

taking into account different 

environmental conditions and exposure 

scenarios, and then estimates risk by 

comparing those potential exposures to 

toxicity values. 

III. Description and Preliminary

Findings of the EPA’s Draft Risk

Assessment

A. Scope of the Draft Risk Assessment

The EPA’s draft risk assessment

describes the potential human health 

and environmental risks associated with 

land application, surface disposal, and 

incineration of sewage sludge 

containing PFOA or PFOS, which are 

the use and disposal practices regulated 

under CWA section 405(d) and the 

EPA’s accompanying regulation at 40 

CFR part 503, Standards for the Use or 

Disposal of Sewage Sludge. The draft 

risk assessment does not assess human 

health or environmental risks associated 

with sewage sludge disposal in MSW 

landfills, a common management 

practice for disposal of sewage sludge, 

because that practice is regulated under 

the Resource Conservation and 

Recovery Act (RCRA) and the EPA’s 

accompanying regulations at 40 CFR 

part 258, Criteria for Municipal Solid 

Waste Landfills. 

The draft risk assessment is scoped to 

model risks to human populations 

because available data indicate that 

humans are more sensitive to PFOA and 

PFOS exposures than aquatic or 

terrestrial wildlife or livestock. For the 

land application scenarios, the EPA 

modeled potential PFOA and PFOS 

exposures and estimated human health 

risks to those living on or near impacted 

properties under three hypothetical 

scenarios: (1) application to a farm 

raising dairy cows, beef cattle, or 

chickens (pasture farm scenario), (2) 

application to a farm growing fruits or 

vegetables (food crop farm scenario),2

and (3) application to reclaim damaged 

soils such as an overgrazed pasture 

(reclamation scenario). For the surface 

disposal scenarios, the EPA modeled 

potential PFOA or PFOS exposures via 

groundwater to those living near a lined 

or unlined surface disposal site (e.g., 

sewage sludge monofill). For the 

incineration scenario, the EPA provides 

a qualitative description of the potential 

risks to communities living near a 

sewage sludge incinerator (SSI). The 

draft risk assessment does not provide 

quantitative risk estimates for the 

incineration scenario due to significant 

data gaps related to the extent to which 


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3Based on currently available information, 

sewage sludge incinerators may not operate at high 

enough temperatures and long enough residence 

times to fully destroy PFOA and PFOS in sewage 

sludge (see the Interim Guidance on the Destruction 

and Disposal of Perfluoroalkyl and Polyfluoroalkyl 

Substances and Materials Containing Perfluoroalkyl 

and Polyfluoroalkyl Substances—Version 2 (2024), 

available at: https://www.epa.gov/pfas/interimguidance-destruction-and-disposal-pfas-andmaterials-containing-pfas). 

4The risk threshold for non-cancer human health 

effects is a hazard quotient equal to one, i.e., when 

the exposure is equal to the reference dose (RfD). 

The threshold for cancer effects is a lifetime excess 

cancer risk of 1 × 10¥6, i.e., when the lifetime 

average daily dose results in one extra cancer case 

per million people above the background cancer 

incidence. 

5Though EPA Method 1633 recommends that 

laboratories develop their own limit of 

quantification (LOQ) and method detection limit 

(MDL) when measuring PFAS in sewage sludge, 

most laboratories running this method achieve 

LOQs and MDLs of 1 ppb or lower for PFOA and 

PFOS (see https://www.epa.gov/cwa-methods/cwaanalytical-methods-and-polyfluorinated-alkylsubstances-pfas). 

incineration in an SSI destroys PFOA 

and PFOS and the health effects of 

exposure to products of incomplete 

combustion.3

B. Modeling Approaches 

The EPA first performed a screeninglevel risk analysis for PFOA and PFOS 

in sewage sludge using a high-end 

deterministic exposure model for a 

hypothetical farm. This screening 

approach assumed high starting 

concentrations of PFOA and PFOS in 

sewage sludge (approximating a 95th 

percentile concentration based on 

available data), high-end consumption 

rates for each exposure pathway (e.g., 

90th percentile consumption rates for 

drinking water intake, milk 

consumption), and other high-end 

factors. The high-end screening model 

resulted in risks exceeding the EPA’s 

acceptable thresholds for every 

individual human exposure pathway 

(e.g., drinking water, consumption of 

fish, milk, beef, vegetables). Given that 

the risk estimates greatly exceeded the 

agency’s acceptable thresholds in the 

screening-level assessment, the EPA 

next moved on to a refined risk 

assessment. In this assessment, the EPA 

refined the modeling approach and 

assessed risks under median (i.e., 

central tendency, 50th percentile), 

rather than high-end exposure 

conditions, to better understand the 

potential scope and magnitude of risks 

under different use and disposal 

scenarios. To complete the central 

tendency deterministic modeling steps 

of the refined risk assessment, the EPA 

(1) identified available fate and 

transport models to select the best 

models for assessing PFOA and PFOS, 

and (2) parameterized the models with 

inputs and exposure factors to reflect 

median U.S. conditions and 

consumption behaviors. For example, 

when calculating risks from egg 

consumption in the central tendency 

approach, the model assumes that an 

adult living on a farm consumes, on 

average, 1 egg per day from the 

impacted property for ten years, which 

represents the median egg consumption 

rate reported in the EPA’s Exposure 

Factors Handbook for households who 

farm (see https://www.epa.gov/expobox/ 

about-exposure-factors-handbook, Table 

13–40). The model further assumes that 

when the adult lives on the impacted 

farm, they have no sources of PFOA or 

PFOS exposure other than the 

contaminated eggs and that for the 

remainder of the adult’s life, they have 

no exposure to PFOA or PFOS through 

any pathway. 

C. Preliminary Findings of the Central 

Tendency Modeling 

The findings summarized here and 

presented in the draft risk assessment 

are preliminary. The EPA expects to 

publish a final risk assessment after 

reviewing public comments and 

revising the draft risk assessment 

accordingly. Based on the modeling 

results of the refined risk assessment for 

the central tendency (median) exposure 

scenarios, the EPA has found that draft 

risk estimates exceed the agency’s 

acceptable human health risk 

thresholds 4 for some pasture farm, food 

crop farm, and reclamation scenarios 

when assuming that the land-applied 

sewage sludge contains 1 part per 

billion (ppb) 5 of PFOA or PFOS. The 

EPA also finds that there are human 

health risks associated with drinking 

contaminated groundwater sourced near 

a surface disposal site when sewage 

sludge containing 1 ppb of PFOA or 

sewage sludge containing 4 to 5 ppb of 

PFOS is disposed in an unlined or claylined surface disposal unit. 

Not all farms or disposal sites where 

sewage sludge containing PFOA or 

PFOS have been used or disposed of are 

expected to pose a risk to human health. 

For example, human health risks are 

expected to be lower when sewage 

sludge is applied to areas with protected 

groundwater, sites that are distant from 

surface waters used for fishing or as a 

drinking water source, and when 

applied to non-food crops, such as 

grain, fuel, or fiber crops. However, the 

EPA’s modeling results from the draft 

risk assessment suggest that under 

certain scenarios and conditions, landapplying or disposing of sewage sludge 

containing a detectable level (i.e., 1 ppb 

or more) of PFOA or PFOS could result 

in human health risks exceeding the 

agency’s acceptable thresholds for 

cancer and non-cancer effects. At this 

low level (1 ppb) of PFOA or PFOS in 

sewage sludge, the EPA modeled land 

application scenarios for either a single 

application at a rate of 50 dry metric 

tons (dmt) per hectare (reclamation 

scenario) or 40 annual applications at a 

rate of 10 dmt per hectare 

(approximately the median application 

rate of U.S. sewage sludge; used for 

pasture and food crop farm scenarios). 

Each of these modeled scenarios 

resulted in exceedances of risk 

thresholds for several exposure 

pathways (e.g., consumption of drinking 

water, fish, beef, milk, eggs, certain 

fruits and vegetables). The EPA’s 

modeling indicates that, for a subset of 

the modeled scenarios and pathways, 

there may be potential risks exceeding 

acceptable levels following a single 

application of sewage sludge 

contaminated with 1 ppb of PFOA or 

PFOS, applied at a rate of 10 dmt per 

hectare (median rate). 

The presence and magnitude of 

human health risks from sewage sludge 

use and disposal to those living on or 

near impacted properties or primarily 

relying on their products is expected to 

vary across regions and among 

properties depending on the 

concentration of PFOA and PFOS in 

sewage sludge; the number of land 

applications; the volume of sewage 

sludge land applied; the climate, 

geology, and hydrology at the use or 

disposal site; agronomic practices; 

human behavioral patterns (e.g., 

drinking water ingestion rates, 

consumption rate of impacted 

products); and many other site-specific 

factors. 

Draft risk estimates for the modeled 

scenarios are presented in the risk 

assessment as cancer risk levels and 

hazard quotients (HQs). Cancer risk 

levels represent the number of expected 

excess lifetime cancer cases due to 

exposure to the carcinogenic pollutant 

in a given population size. For example, 

a cancer risk level of 1 in 1,000 

indicates that lifetime exposure to the 

carcinogenic pollutant would be 

expected to cause one additional case of 

cancer for every one thousand people in 

the exposed population. Risk for noncancer effects are expressed as HQs that 

represent the ratio of the potential 

exposure to a pollutant to the level 

below which adverse non-cancer effects 

are not expected. In other words, an HQ 

of less than 1 means adverse non-cancer 

health effects are unlikely and thus risk 

can be considered negligible; an HQ 

greater than 1 means adverse non-cancer 


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Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Notices 3863 

effects are possible and thus risk is 

indicated. 

Modeling for land application 

scenarios suggests that, when the 

majority of the consumer’s dietary 

intake of a product comes from a 

property impacted by the land 

application of sewage sludge 

contaminated with PFOA or PFOS, the 

highest risk pathways include (1) 

drinking milk from pasture-raised cows 

consuming contaminated forage, soil, 

and water, (2) drinking water sourced 

from contaminated surface or 

groundwater on or adjacent to the 

impacted property, (3) eating fish from 

a lake impacted by runoff from the 

impacted property, and (4) eating beef 

or eggs from majority pasture-raised 

hens or cattle where the pasture has 

received impacted sewage sludge. The 

risk calculations assume each of these 

farm products (e.g., milk, beef, eggs) or 

drinking water consumed comes from 

the impacted property but does not 

combine risks from each of these 

products. The EPA did not estimate risk 

associated with occasionally consuming 

products or drinking water impacted by 

land application of contaminated 

sewage sludge nor foods that come from 

a variety of sources (e.g., milk from a 

grocery store that is sourced from many 

farms and mixed together before being 

bottled). Additionally, the majority of 

food produced in the U.S. is not grown 

on fields where sewage sludge is land 

applied. 

Risk estimates for the highest risk 

pathways can exceed the EPA’s 

acceptable thresholds by several orders 

of magnitude. For example, for the land 

application scenarios, cancer risk levels 

associated with drinking the modeled 

amount of contaminated milk (i.e., 32 

ounces per day for adults) can exceed 1 

in 1,000, and HQs for non-cancer effects 

associated with eating the modeled 

amount of contaminated fish (i.e., 1 to 

2 servings per week for adults) can 

reach up to 45. For the food crop farm 

scenario, there are limited scientific 

studies available regarding the uptake of 

PFOA and PFOS from sewage sludgeamended soils into certain fruits and 

vegetables; however, the draft risk 

assessment suggests that cancer risks 

from consuming the modeled amount of 

these contaminated foods (e.g., 1 serving 

per day for adults for certain categories 

of fruits and vegetables) can exceed 1 in 

100,000 for PFOA. Because the draft risk 

assessment indicates risks associated 

with individual exposure pathways, 

there may be potential risks to 

populations beyond the farm family 

(e.g., people living near a use or 

disposal site who use contaminated 

groundwater as a source of drinking 

water or people who primarily consume 

produce, dairy, or meat from a farm that 

has applied contaminated sewage 

sludge under the modeled conditions). 

For the surface disposal sites, there 

are no exceedances of the EPA’s risk 

thresholds for PFOA or PFOS in 

drinking water sourced from 

groundwater near composite-lined 

surface disposal sites. However, for 

unlined and clay-lined surface disposal 

sites, there can be exceedances of the 

risk thresholds for the drinking water 

pathway; for unlined sites, the cancer 

risk levels can exceed 1 in 1,000 and 

HQs are as high as 12; for clay-lined 

sites, the cancer risk levels can exceed 

1 in 1,000 and HQs are up to 9. As 

mentioned above, the draft risk 

assessment does not include 

quantitative risk estimates for 

incineration due to data limitations. 

The draft risk calculations are not 

conservative estimates because they (1) 

model risks associated with sludge 

containing 1 ppb of PFOA or PFOS, 

which is on the low end of measured 

U.S. sewage sludge concentrations, (2) 

reflect median exposure conditions (e.g., 

50th percentile drinking water intake 

rates) rather than high exposure 

conditions, (3) do not include nonsewage sludge exposures to PFOA or 

PFOS (e.g., consumer products, other 

dietary sources), (4) do not account for 

the combined risk of PFOA and PFOS 

together, and (5) do not account for 

exposures from the transformation of 

PFOA or PFOS precursors. As such, risk 

estimates that account for multiple 

dietary exposures (e.g., consuming 

impacted milk, water, and eggs), 

multiple sources of exposure (e.g., 

exposure to PFOA or PFOS-containing 

consumer products), or exposure to 

other PFAS would be greater than those 

presented in this draft risk assessment. 

Further, the EPA’s draft risk assessment 

relies on models where risks scale 

linearly with the starting concentration 

of PFOA or PFOS in sewage sludge. As 

such, sewage sludge containing ten 

times more PFOA or PFOS (i.e., 10 ppb) 

would yield risk estimates that are ten 

times greater than those presented in the 

draft risk assessment, assuming all other 

factors are constant. 

The EPA did not complete Monte 

Carlo probabilistic modeling because 

risks exceeding acceptable thresholds 

were identified in multiple scenarios 

and pathways in the central tendency 

deterministic modeling results. Further 

refinement of the draft risk assessment 

from the central tendency deterministic 

models to Monte Carlo probabilistic 

models would result in an increased 

risk finding because the EPA’s goal for 

a probabilistic assessment is to identify 

a high-end (e.g., 95th percentile) 

threshold protective of the impacted 

population (e.g., farm families), while a 

central tendency approach, which the 

EPA used in this case, models a person 

at the 50th percentile exposure level of 

the impacted population. Since risk is 

indicated under this central tendency 

scenario, Monte Carlo probabilistic 

modeling, which would examine the 

entire distribution of potential 

exposures to PFOA or PFOS and report 

the 95th percentile of the risk 

distribution, is not warranted at this 

time. For this reason, the EPA is focused 

on the central tendency modeling 

results and identifying actions that 

could be taken to mitigate risks. 

IV. Next Steps 

A. Risk Reduction 

The draft risk assessment indicates 

that there are potential risks to human 

health to those living on or near 

impacted properties or primarily relying 

on their products from land application 

and surface disposal of sewage sludge 

containing detectable levels of PFOA or 

PFOS. That risk is dependent on (1) the 

concentration of PFOA and PFOS in 

sewage sludge, (2) the specific type of 

management practice (e.g., type of farm 

or presence of a liner in a monofill), (3) 

the local environmental and geological 

conditions (e.g., climate and distance to 

groundwater), (4) the share of each 

product (e.g., food crop, drinking water) 

that is sourced exclusively from the 

impacted property, and other factors 

noted above. Risks are possible, though 

not quantified due to data limitations, 

from the incineration of PFOA and 

PFOS-containing sewage sludge. Sitespecific factors should be considered 

when identifying risk mitigation and 

management practices to reduce human 

exposures associated with PFOA and 

PFOS in sewage sludge. 

Regardless of the management 

practice to use or dispose of sewage 

sludge, exposure and risk reduction is 

possible through pretreatment at 

industrial facilities discharging to a 

WWTP. By monitoring sewage sludge 

for PFOA and PFOS, WWTPs can 

identify likely discharges of PFOA and 

PFOS from industrial contributors, 

require pretreatment, and achieve 

significant reductions in PFOA and 

PFOS concentrations in their sewage 

sludge. In some state programs, WWTPs 

with industrial sources have achieved a 

98 percent reduction in PFOS sewage 

sludge concentrations through 

industrial pretreatment initiatives. The 

EPA recommends that states, Tribes, 

and WWTPs monitor sewage sludge for 

PFAS contamination, identify likely 


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3864 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Notices 

industrial discharges of PFAS, and 

implement industrial pretreatment 

requirements, where appropriate. Doing 

so will help reduce downstream PFAS 

contamination and lower the 

concentration of PFOA and PFOS in 

sewage sludge (see Section C of the 

EPA’s December 2022 memorandum 

Addressing PFAS Discharges in NPDES 

Permits and Through the Pretreatment 

Program and Monitoring Programs, 

available at: https://www.epa.gov/ 

newsreleases/epa-issues-guidancestates-reduce-harmful-pfas-pollution). 

B. Related Actions 

The EPA is planning to conduct the 

next National Sewage Sludge Survey 

(NSSS) in collaboration with the 

publicly owned treatment works 

(POTW) Influent PFAS Study (see 

https://www.epa.gov/biosolids/sewagesludge-surveys). This NSSS will focus 

on obtaining current national 

occurrence and concentration data on 

PFAS in sewage sludge. The data 

generated by the NSSS will help inform 

future risk assessments and risk 

management actions for sewage sludge. 

Additionally, the EPA continues to 

evaluate opportunities to limit PFAS 

discharges from multiple industrial 

categories through the Effluent 

Guidelines Program. The specific 

actions include revising the Organic 

Chemicals, Plastics, and Synthetic 

Fibers Effluent Limitations Guidelines 

(ELGs) to address wastewater discharge 

from PFAS manufacturing facilities; 

revising the Metal Finishing and 

Electroplating ELGs to address 

wastewater discharge from metal 

finishing and electroplating operations 

focusing on facilities using PFAS-based 

fume suppressants and wetting agents; 

and revising the Landfills ELGs to 

address PFAS discharges from landfill 

leachate. The upcoming POTW Influent 

PFAS Study will also help the agency 

prioritize industrial point source 

categories for future study and, as 

appropriate, ELGs (see https://

www.epa.gov/eg/study-pfas-influentpotws). 

C. Final Risk Assessment and Potential 

Future Actions 

After the public comment period has 

closed, the EPA will consider the 

comments received, revise the draft risk 

assessment as appropriate, and prepare 

a final risk assessment. The EPA will 

announce the availability of the final 

risk assessment in the Federal Register. 

If the final risk assessment indicates that 

there are risks above acceptable 

thresholds when using or disposing of 

sewage sludge, the EPA expects to 

propose a regulation under CWA section 

405 to manage PFOA and/or PFOS in 

sewage sludge to protect public health 

and the environment. The EPA may also 

consider developing regulations under 

other statutory authorities to further 

reduce PFAS discharged to WWTPs. 

During the risk management 

deliberation process, the results of the 

final risk assessment may be integrated 

with other considerations, such as 

economic costs and treatment 

feasibility, to reach decisions regarding 

the need for and practicability of 

implementing various risk reduction 

activities. If the EPA proposes 

regulatory standards for PFOA and/or 

PFOS in sewage sludge, the public will 

have an opportunity to provide 

comment. 

Bruno Pigott, 

Principal Deputy Assistant Administrator. 

[FR Doc. 2025–00734 Filed 1–14–25; 8:45 am] 

BILLING CODE 6560–50–P 

FEDERAL COMMUNICATIONS 

COMMISSION 

[OMB 3060–0392; FR ID 272605] 

Information Collection Being Reviewed 

by the Federal Communications 

Commission Under Delegated 

Authority 

AGENCY: Federal Communications 

Commission. 

ACTION: Notice and request for 

comments. 

SUMMARY: As part of its continuing effort 

to reduce paperwork burdens, and as 

required by the Paperwork Reduction 

Act (PRA) of 1995, the Federal 

Communications Commission (FCC or 

the Commission) invites the general 

public and other Federal agencies to 

take this opportunity to comment on the 

following information collection. 

Comments are requested concerning: 

whether the proposed collection of 

information is necessary for the proper 

performance of the functions of the 

Commission, including whether the 

information shall have practical utility; 

the accuracy of the Commission’s 

burden estimate; ways to enhance the 

quality, utility, and clarity of the 

information collected; ways to minimize 

the burden of the collection of 

information on the respondents, 

including the use of automated 

collection techniques or other forms of 

information technology; and ways to 

further reduce the information 

collection burden on small business 

concerns with fewer than 25 employees. 

The FCC may not conduct or sponsor 

a collection of information unless it 

displays a currently valid control 

number. No person shall be subject to 

any penalty for failing to comply with 

a collection of information subject to the 

PRA that does not display a valid Office 

of Management and Budget (OMB) 

control number. 

DATES: Written PRA comments should 

be submitted on or before March 17, 

2025. If you anticipate that you will be 

submitting comments, but find it 

difficult to do so within the period of 

time allowed by this notice, you should 

advise the contact listed below as soon 

as possible. 

ADDRESSES: Direct all PRA comments to 

Nicole Ongele, FCC, via email PRA@

fcc.gov and to nicole.ongele@fcc.gov. 

FOR FURTHER INFORMATION CONTACT: For 

additional information about the 

information collection, contact Nicole 

Ongele, (202) 418–2991. 

SUPPLEMENTARY INFORMATION: 

OMB Control Number: 3060–0392. 

Title: 47 CFR 1 Subpart J—Pole 

Attachment Complaint Procedures. 

Form Number: N/A. 

Type of Review: Extension of 

currently approved collection. 

Respondents: Businesses or other forprofit. 

Number of Respondents and 

Responses: 1,760 respondents; 1,760 

responses. 

Estimated Time per Response: 0.50 

hours (30 minutes)–75 hours. 

Frequency of Response: On occasion 

reporting requirements. 

Obligation to Respond: Required to 

obtain or retain benefits. Statutory 

authority for this information collection 

is contained in 47 U.S.C. 224. 

Total Annual Burden: 2,759 hours. 

Total Annual Cost: $15,000. 

Needs and Uses: Currently, OMB 

Collection No. 3060–0392, tracks the 

burdens associated with requests for 

access to a utility’s poles, notifications 

between utility pole owners and 

attachers needed for the shared use of 

utility poles, as well as the filing of 

complaints and petitions for stay against 

the actions of said utilities. The 

Commission will use the information 

collected to assess whether the petition 

or complaint can proceed as a docketed 

case. 

Federal Communications Commission. 

Marlene Dortch, 

Secretary, Office of the Secretary. 

[FR Doc. 2025–00645 Filed 1–14–25; 8:45 am] 

BILLING CODE 6712–01–P 


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