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[Federal Register Volume 90, Number 11 (Friday, January 17, 2025)]
[Notices]
[Pages 5880-5881]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-01072]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-R06-OW-2023-0566; FRL-11561-02-R6]

Revised Designation Decision and Record of Decision in Response 
to a Petition by Amigos Bravos for a Determination That Stormwater 
Discharges in Los Alamos County Contribute to Water Quality Standards 
Violations and Require Clean Water Act Permit Coverage

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: The Environmental Protection Agency (EPA) Region 6 is 
providing notice of a Revised Designation Decision that storm water 
discharges from the Los Alamos Urban Area (as defined by the latest 
decennial Census) and Los Alamos National Laboratory (LANL) property in 
Los Alamos County and Santa Fe County, New Mexico are contributing to 
violations of New Mexico Water Quality Standards (WQS) and require 
National Pollutant Discharge Elimination System (NPDES) permit coverage 
under the Clean Water Act (CWA). This action is in response to a June 
30, 2014, petition filed with EPA by Amigos Bravos entitled ``A 
Petition by Amigos Bravos for a Determination that Storm Water 
Discharges in Los Alamos County Contribute to Water Quality Standards 
Violations and Require a Clean Water Act Permit,'' and revises the 
Agency's prior December 16, 2019, designation decision, which was 
remanded to EPA for reconsideration by the United States Court of 
Appeals for the Tenth Circuit.

DATES: The ``Revised Designation Decision and Record of Decision in 
Response to A Petition by Amigos Bravos for a Determination that 
Stormwater Discharges in Los Alamos County Contribute to Water Quality 
Standards Violations and Require Clean Water Act Permit Coverage'' was 
signed on December 9, 2024. Please refer to the SUPPLEMENTARY 
INFORMATION section for additional information.

ADDRESSES: For further information contact Ms. Evelyn Rosborough via 
email: [email protected], or by mail at Ms. Evelyn Rosborough, 
Environmental Protection Agency, Region 6, Water Division (6WQ-NP), 
1201 Elm Street, Suite 500, Dallas, TX 75270.

SUPPLEMENTARY INFORMATION:

General Information

A. Does this action apply to me?

    Small Municipal Separate Storm Sewer Systems (MS4s) operated by the 
County of Los Alamos, the New Mexico Department of Transportation 
(NMDOT), and Los Alamos National Laboratory (LANL), including Triad 
National Security, LLC and the U.S. Department of Energy's National 
Nuclear Security Administration, will be regulated as a result of this 
action. To determine whether your entity is affected by this action, 
you should also review the description of EPA's action in Section II.B 
of this notice and the Revised Designation Decision document available 
in Docket ID No. EPA-R06-OW-2023-0566 at the Federal eRulemaking 
Portal: https://www.regulations.gov/ or online via the EPA Residual 
Designation web page at: https://www.epa.gov/npdes/epas-residual-designation-authority. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in ADDRESSES section.

B. Summary and Availability of Revised Designation Documents

    The Regional Administrator of EPA Region 6 has made a revised 
designation of stormwater discharges from certain MS4s for regulation 
under the NPDES permitting program pursuant to Section 402(p)(2)(E) and 
(6) of the CWA and EPA's implementing regulations at 40 CFR 
122.26(a)(9)(i)(C)-(D). Those provisions authorize the Agency to 
designate for regulation stormwater discharges that contribute to a WQS 
violation or that are a significant contributor of pollutants to waters 
of the United States, or where controls are needed based on wasteload 
allocations that are part of total maximum daily loads. This authority 
is often referred to as ``residual designation authority'' or RDA. EPA 
is providing notice of its

[[Page 5881]]

Revised Designation Decision that storm water discharges from the Los 
Alamos Urban Area (as defined by the latest decennial Census) and LANL 
property in Los Alamos County and Santa Fe County, New Mexico are 
contributing to violations of New Mexico WQS and require NPDES permit 
coverage under the CWA.
    This Revised Designation Decision revises EPA's prior December 16, 
2019, decision designating stormwater discharges from small MS4s 
operated by the County of Los Alamos, LANL, and the New Mexico 
Department of Transportation for NPDES permitting. EPA has carefully 
considered all record information, including stormwater discharge data 
and other information submitted by Los Alamos County, NMED, LANL, and 
the Buckman Direct Diversion, NMED's water quality assessments and 
lists of impaired waters, and supplemental information submitted by 
LANL and the County regarding EPA's previous 2019 designation decision, 
as well as the public comments submitted on that decision when it was 
proposed. EPA also conducted a site visit in September 2022 to examine 
first-hand the effects of the discharges and waters at issue.
    Upon reconsideration of the Petition on remand, EPA has determined 
that stormwater discharges from small MS4s located in the Los Alamos 
Urban Area as defined by the latest decennial Census and MS4s located 
on LANL property within Los Alamos and Santa Fe Counties, New Mexico 
require NPDES permit coverage because the discharges are contributing 
to violations of NM WQS in waters of the United States. The Revised 
Designation Decision plus supplementary information, including the 
response to comments document, relating to it are available in Docket 
ID No. EPA-R06-OW-2023-0566 at the Federal eRulemaking Portal: https://www.regulations.gov/ or online via the EPA Residual Designation web 
page at: https://www.epa.gov/npdes/epas-residual-designation-authority.

    Dated: December 19, 2024.
Troy Hill,
Director, Water Division, Region 6.
[FR Doc. 2025-01072 Filed 1-16-25; 8:45 am]
BILLING CODE 6560-50-P
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