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National Pollutant Discharge Elimination System (NPDES)

Petition to Designate Sources in Los Alamos County, New Mexico

In June 2014, EPA Region 6 received a petition from Amigos Bravos requesting that EPA designate certain stormwater discharges in Los Alamos County, New Mexico as needing NPDES permits due to contributions to exceedances of state water quality standards in receiving waters. After careful analysis of the Petition, comments on its 2015 Preliminary Designation, and all other available information, on December 16, 2019, EPA designated for NPDES permitting as regulated small MS4s the following: MS4s located in the portion of Los Alamos County, New Mexico within the Los Alamos Urban Cluster as defined by the latest Decennial Census, and MS4s located on Los Alamos National Laboratory property located within Los Alamos County and Santa Fe County, New Mexico. 

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