APPENDIX

11a
millions of cars and deposited as a thin film
on highways; minute particles of copper dust
from brake linings are spread across roads
and parking lots each time a driver applies
the brakes; drips and drabs of oil and gas
ubiquitously stain driveways and streets.
When it rains, the rubber particles and copper
dust and gas and oil wash off of the
streets and are carried along by runoff in a
polluted soup, winding up in creeks, rivers,
bays, and the ocean.
However, when stormwater runoff is collected in a
system of ditches, culverts, and channels and is then
discharged into a stream or river, there is a “discernable,
confined and discrete conveyance” of pollutants,
and there is therefore a discharge from a point
source. In other words, runoff is not inherently a
nonpoint or point source of pollution. Rather, it is a
nonpoint or point source under § 502(14) depending
on whether it is allowed to run off naturally (and is
thus a nonpoint source) or is collected, channeled,
and discharged through a system of ditches, culverts,
channels, and similar conveyances (and is thus a
point source discharge).
Our caselaw has consistently recognized the distinction
between nonpoint and point source runoff. In
Natural Resources Defense Council v. California Department
of Transportation, 96 F.3d 420, 421 (9th
Cir. 1996), we were asked to enforce an alreadyissued
NPDES permit requiring a state agency using
storm drains “to control polluted stormwater runoff
from roadways and maintenance yards[.]” In Natural
Resources Defense Council v. EPA (“NRDC v. EPA”),
966 F.2d 1292, 1295 (9th Cir. 1992), we wrote, “This
case involves runoff from diffuse sources that even-