As the Act requires a point source, not seeping groundwater or permeable hydrological network, the pollution here is outside of its scope.
http://www.opn.ca6.uscourts.gov/opinions.pdf/18a0214p-06.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.