Northwest Environmental Defense Center v. Brown

FOR PUBLICATION
UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT

NORTHWEST ENVIRONMENTAL 
DEFENSE CENTER, an Oregon non-
profit corporation,
Plaintiff-Appellant,
and
OREGON FOREST INDUSTRY COUNCIL;
AMERICAN FOREST & PAPER
ASSOCIATION,
Intervenors,
v. No. 07-35266
MARVIN BROWN, Oregon State D.C. No.
Forester, in his official capacity; CV-06-01270-GMK
STEPHEN HOBBS; BARBARA CRAIG;
DIANE SNYDER; LARRY GIUSTINA;
WILLIAM HEFFERNAN; WILLIAM
 ORDER
WITHDRAWING
HUTCHISON; JENNIFER PHILLIPPI, OPINION AND
(members of the Oregon Board of DENYING
Forestry, in their official REHEARING AND
capacities); HAMPTON TREE FARMS, OPINION
INC., an Oregon domestic business
corporation; STIMSON LUMBER
COMPANY, an Oregon domestic
business corporation; GEORGIA-
PACIFIC WEST INC., an Oregon
domestic business corporation;
SWANSON GROUP, INC., an Oregon
domestic business corporation;
TILLAMOOK COUNTY,
Defendants-Appellees.


6401
6402 NEDC v. BROWN
Appeal from the United States District Court
for the District of Oregon
Garr M. King, District Judge, Presiding

Argued and Submitted
November 19, 2008—Portland, Oregon

Filed May 17, 2011

Before: William A. Fletcher and Raymond C. Fisher,
Circuit Judges, and Charles R. Breyer,* District Judge.

Opinion by Judge William A. Fletcher

*The Honorable Charles R. Breyer, United States District Judge for the
Northern District of California, sitting by designation.
 NEDC v. BROWN 6405

COUNSEL

Paul A. Kampmeier, WASHINGTON FOREST LAW CEN-
TER, Seattle, Washington; Christopher G. Winter, CRAG
LAW CENTER, Portland, Oregon, for the plaintiff-appellant.

Per A. Ramfjord, Louis A. Ferreira, J. Mark Morford,
STOEL RIVES LLP, Portland, Oregon, for defen-
dants-appellees Hampton Tree Farms, Inc., Stimson Lumber
Co., Georgia-Pacific West, Inc. and Swanson Group, Inc.

Per A. Ramfjord, Louis A. Ferreira, J. Mark Morford,
STOEL RIVES LLP, Portland, Oregon, for intervenor Ore-
gon Forest Industries Council; Ellen B. Steen, CROWELL &
MOORING, Washington, D.C. for intervenor American For-
est and Paper Association; and William K. Sargent, Tila-
mook, Oregon, for intervenor Tillamook County.

Marc Abrams, Erin C. Lagesen, Richard D. Wasserman,
OFFICE OF THE OREGON ATTORNEY GENERAL,
Salem, Oregon; Louis A. Ferreira, J. Mark Morford, Per
Albert Ramfjord, STOEL RIVES LLP, Portland, Oregon;
William K. Sargent, Tillamook, Oregon, for the defendants-
appellees.
6406 NEDC v. BROWN
Damien M. Schiff and Ralph W. Kasarda, PACIFIC LEGAL
FOUNDATION, Sacramento, California; Michele A. Dias,
CALIFORNIA FORESTRY ASSOCIATION, Sacramento,
California, for Amici PACIFIC LEGAL FOUNDATION and
CALIFORNIA FORESTRY ASSOCIATION in support of
the defendants-appellees.

Bradford T. McLane, US DEPARTMENT OF JUSTICE,
Washington, D.C., William C. Carpenter, Eugene, Oregon,
for the amici-curiae.

Michael R. Lozeau and Douglas J. Chermack, LOZEAU
DRURY LLP, Oakland, California; Sharon Buccino, NATU-
RAL RESOURCES DEFENSE COUNCIL, Washington,
D.C., Sharon E. Duggan, LAW OFFICES OF SHARON E.
DUGGAN, for amicus curiae NATURAL RESOURCES
DEFENSE COUNCIL, INC., and the ENVIRONMENTAL
PROTECTION INFORMATION CENTER in support of the
plaintiffs-appellants.

ORDER

This court’s opinion filed August 17, 2010, and reported at
617 F.3d 1176, is withdrawn, and is replaced by the attached
Opinion.

With the filing of the new opinion, the panel has voted
unanimously to deny the petitions for rehearing. Judges
Fletcher and Fisher have voted to deny the petitions for
rehearing en banc, and Judge Breyer so recommends.

The full court has been advised of the petitions for rehear-
ing en banc and no judge of the court has requested a vote on
whether to rehear the matter en banc. Fed. R. App. P. 35.

The petitions for rehearing and rehearing en banc, filed
October 5, 2010, are DENIED.
 NEDC v. BROWN 6407
No further petitions for rehearing or rehearing en banc will
be accepted.

OPINION

W. FLETCHER, Circuit Judge:

Northwest Environmental Defense Center (“NEDC”)
brings suit against the Oregon State Forester and members of
the Oregon Board of Forestry in their official capacities (col-
lectively, “State Defendants”) and against various timber
companies (“Timber Defendants,” and collectively with State
Defendants, “Defendants”). NEDC contends that Defendants
have violated the Clean Water Act (“CWA”) and its imple-
menting regulations by not obtaining permits from the Envi-
ronmental Protection Agency (“EPA”) for stormwater —
largely rainwater — runoff that flows from logging roads into
systems of ditches, culverts, and channels and is then dis-
charged into forest streams and rivers. NEDC contends that
these discharges are from “point sources” within the meaning
of the CWA and that they therefore require permits under the
National Pollutant Discharge Elimination System (“NPDES”).

The district court concluded that the discharges are
exempted from the NPDES permitting process by the Silvi-
cultural Rule, 40 C.F.R. § 122.27, promulgated under the
CWA to regulate discharges associated with silvicultural
activity. The district court did not reach the question whether
the discharges are exempted by amendments to the CWA
made in 1987. We reach both questions and conclude that the
discharges require NPDES permits.

I. Background

NEDC contends that discharges from systems of ditches,
culverts, and channels that receive stormwater runoff from
6408 NEDC v. BROWN
two logging roads in the Tillamook State Forest in Oregon are
point source discharges under the CWA. The roads are the
Trask River Road, which runs parallel to the South Fork
Trask River, and the Sam Downs Road, which runs parallel
to the Little South Fork of the Kilchis River. The roads are
owned by the Oregon Department of Forestry and the Oregon
Board of Forestry. They are primarily used by the Timber
Defendants to gain access to logging sites and to haul timber
out of the forest. The Timber Defendants use the roads pursu-
ant to timber sales contracts with the State of Oregon. These
contracts designate specific routes for timber hauling and
require that the Timber Defendants maintain the roads and
their associated stormwater collection systems.

Both of the logging roads were designed and constructed
with systems of ditches, culverts, and channels that collect
and convey stormwater runoff. For most of their length, the
roads are graded so that water runs off the road into ditches
on the uphill side of the roads. There are several ways these
ditches then deliver water into the adjacent rivers. At inter-
vals, the ditches empty into “cross-drain” culverts that cross
under the roads. Where the roads are close to the rivers, these
culverts deliver the collected stormwater into the rivers.
Where the roads are at some distance from the rivers, the
roadside ditches connect to culverts under the roads that
deliver the collected stormwater into channels, and these
channels then discharge the stormwater into the rivers. When
tributary streams cross under the roads, the roadside ditches
deliver the collected stormwater into these streams. These
streams then carry the collected stormwater to the rivers.

The stormwater runoff that flows off the roads and through
these collection systems deposits large amounts of sediment
into streams and rivers. This sediment adversely affects fish
— in particular, salmon and trout — by smothering eggs,
reducing oxygen levels, interfering with feeding, and burying
insects that provide food.
 NEDC v. BROWN 6409
Timber hauling on the logging roads is a major source of
the sediment that flows through the stormwater collection sys-
tems. Logging trucks passing over the roads grind up the
gravel and dirt on the surface of the road. Small rocks, sand,
and dirt are then washed into the collection system and dis-
charged directly into the streams and rivers. NEDC alleged in
its complaint that it sampled stormwater discharges at six
points along the Trask River Road and five points along the
Sam Downs Road where the Defendants use ditches, culverts,
and channels to collect and then discharge stormwater runoff.
Each sample contained significant amounts of sediment.

None of the Defendants has sought or received NPDES
permits for these discharges into the streams and rivers.
NEDC brought suit under the citizen suit provision of the
CWA, 33 U.S.C. § 1365(a), which provides that “any citizen
may commence a civil action on his own behalf . . . against
any person” alleged to be in violation of the CWA. NEDC
claims that Defendants have violated the CWA by not obtain-
ing NPDES permits. On March 1, 2007, the district court dis-
missed NEDC’s complaint with prejudice under Federal Rule
of Civil Procedure 12(b)(6) for failure to state a claim. NEDC
has timely appealed.

II. Subject Matter Jurisdiction

In the original version of our opinion, we did not discuss
our subject matter jurisdiction. None of the parties to the suit
had raised an objection to subject matter jurisdiction. In an
amicus brief, however, the United States had contended that
the challenged Silvicultural Rule was unambiguous and that,
as a consequence, citizen-suit jurisdiction under 33 U.S.C.
§ 1365(a) was improper. Instead, the United States had
argued, the suit should have been brought under 33 U.S.C.
§ 1369(b). A defect in subject matter jurisdiction is, of course,
not waivable.

Without discussing subject matter jurisdiction, we held on
the merits that the Silvicultural Rule is ambiguous. After we
6410 NEDC v. BROWN
published our opinion, one of our colleagues asked us to dis-
cuss our subject matter jurisdiction. We asked for supplemen-
tal briefing. In light of our holding that the Rule is ambiguous,
the United States now concedes, in a second amicus brief, that
we have subject matter jurisdiction under § 1365(a). We agree
with the United States.

A citizen can bring a suit under § 1365(a) against any per-
son, including the United States, who is alleged to be in viola-
tion of “an effluent standard or limitation” under the CWA.
A citizen suit may be brought against a person or entity ille-
gally discharging a pollutant into covered waters without an
NPDES permit. Id. at § 1365(f)(6). Suits under § 1365, how-
ever, are limited by the CWA’s judicial review mechanism at
§ 1369(b). Section 1369(b) provides for the review of various
actions of the EPA Administrator, including the promulgation
of effluent standards, prohibitions, or limitations, as soon as
those actions take place. Id. at § 1369(b)(1). Such suits must
be brought within 120 days from the date of the Administra-
tor’s “determination, approval, promulgation, issuance or
denial,” unless the basis for the suit arose more than 120 days
after the agency action. Id. Any action that could have been
brought under § 1369(b) “shall not be subject to judicial
review in any civil or criminal proceeding for enforcement.”
Id. at § 1369(b)(2).

The basis for NEDC’s challenge to the Silvicultural Rule
arose more than 120 days after the promulgation of the Rule.
As we discuss in greater detail below, the Silvicultural Rule
is susceptible to two different readings. Under one reading,
the Rule does not require permits for silviculture stormwater
runoff. Under this reading, the Rule is inconsistent with the
CWA and hence invalid. Under the other reading, the Rule
requires permits for the runoff and is consistent with the
CWA. The United States adopted the first reading of the Sil-
vicultural Rule for the first time in its initial amicus brief in
this case. Until the United States filed that brief, there was no
way for the public to know which reading of the Silvicultural
 NEDC v. BROWN 6411
Rule it would adopt. As the government states in its second
amicus brief to us,

At the time an ambiguous regulation is promulgated
. . . the public cannot reasonably be expected to chal-
lenge potential regulatory interpretations that are tex-
tually plausible but that the agency has not
contemporaneously offered and may never adopt.
Indeed, a rule encouraging such challenges to hypo-
thetical interpretations would likely only foster
unnecessary litigation.

Because the Silvicultural Rule was subject to two readings,
only one of which renders the Rule invalid, and because the
government first adopted its interpretation of the Rule in its
initial amicus brief in this case, this case comes within the
exception in § 1369(b)(1) for suits based on grounds arising
after the 120-day filing window. Section 1369(b) therefore
does not bar a citizen suit challenging EPA’s Silvicultural
Rule interpretation first adopted in its initial amicus brief in
this case. We thus have subject matter jurisdiction under 33
U.S.C. § 1365(a).

III. Standard of Review

We review de novo a district court’s dismissal under Rule
12(b)(6). Knievel v. ESPN, 393 F.3d 1068, 1072 (9th Cir.
2005). We accept as true all of NEDC’s allegations of mate-
rial facts and we construe them in the light most favorable to
NEDC. Id.

We review de novo the district court’s interpretation of the
CWA and its implementing regulations. League of Wilderness
Defenders/Blue Mts. Biodiversity Project v. Forsgren, 309
F.3d 1181, 1183 (9th Cir. 2002). We defer to an agency’s
interpretation of its own regulations unless that interpretation
is plainly erroneous, inconsistent with the regulation, or based
on an impermissible construction of the governing statute.
6412 NEDC v. BROWN
Auer v. Robbins, 519 U.S. 452, 457, 461-62 (1997). We
review EPA’s interpretations of the CWA under Chevron
U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467
U.S. 837, 842-43 (1984). At Chevron step one, if, employing
the “traditional tools of statutory construction,” we determine
that Congress has directly and unambiguously spoken to the
precise question at issue, then the “unambiguously expressed
intent of Congress” controls. Id. at 843. At Chevron step two,
if we determine that the statute is “silent or ambiguous with
respect to the specific issue,” we must determine whether the
agency’s interpretation is based on a permissible construction
of the statute. Id. at 843. An agency interpretation based on
a permissible construction of the statute controls. Id. at 844.

IV. Discussion

NEDC contends that stormwater runoff from logging roads
that is collected in a system of ditches, culverts, and channels,
and is then delivered into streams and rivers, is a point source
discharge subject to NPDES permitting under the CWA.
Defendants, however, contend that the Silvicultural Rule
exempts such runoff from the definition of point source dis-
charge, and thus exempts it from the NPDES permitting pro-
cess. Alternatively, Defendants contend that the 1987
amendments to the CWA and regulations implementing those
amendments exempt such runoff from the definition of point
source discharge and from the permitting process. We discuss,
in turn, the definition of point source discharge, the Silvicul-
tural Rule, and the 1987 amendments to the CWA.

A. Definition of Point Source Discharge

[1] In 1972, in the Federal Water Pollution Control Act
(“FWPCA”), Congress substantially revised federal law gov-
erning clean water. Pub. L. No. 92-500, 86 Stat. 816 (1972).
In 1977, the statute was renamed the Clean Water Act
(“CWA”). Pub. L. No. 95-217, 91 Stat. 1566 (1977). Con-
gress enacted the FWPCA to “restore and maintain the chemi-
 NEDC v. BROWN 6413
cal, physical, and biological integrity of the Nation’s waters”
by replacing water quality standards with point source efflu-
ent limitations. 33 U.S.C. § 1251(a); Or. Natural Desert Ass’n
v. Dombeck, 172 F.3d 1092, 1096 (9th Cir. 1998). Section
301(a) of the Act provides that, subject to certain exceptions,
“the discharge of any pollutant by any person shall be unlaw-
ful.” 33 U.S.C. § 1311(a). One of these exceptions is a point
source discharge authorized by a permit granted pursuant to
the NPDES system under § 402 of the Act. 33 U.S.C. § 1342.
The combined effect of §§ 301(a) and 402 is that “[t]he CWA
prohibits the discharge of any pollutant from a point source
into navigable waters of the United States without an NPDES
permit.” N. Plains Res. Council v. Fid. Exploration & Dev.
Co., 325 F.3d 1155, 1160 (9th Cir. 2003); see also Nw. Envtl.
Advocates v. EPA, 537 F.3d 1006, 1010 (9th Cir. 2008). “Pol-
lutants” include “rock” and “sand.” 33 U.S.C. § 1362(6).
Defendants do not contest that sediment discharges from log-
ging roads constitute pollutants within the meaning of the
CWA.

[2] “It is well settled that the starting point for interpreting
a statute is the language of the statute itself.” Gwaltney of
Smithfield, Ltd. v. Chesapeake Bay Found., Inc., 484 U.S. 49,
56 (1987). Section 502(14) of the Act defines “point source”
as

any discernible, confined and discrete conveyance,
including but not limited to any pipe, ditch, channel,
tunnel, conduit, well, discrete fissure, container, roll-
ing stock, concentrated animal feeding operation, or
vessel or other floating craft, from which pollutants
are or may be discharged. This term does not include
agricultural stormwater discharges and return flows
from irrigated agriculture.

33 U.S.C. § 1362(14) (emphasis added). The term “nonpoint
source” is left undefined.
6414 NEDC v. BROWN
[3] Stormwater that is not collected or channeled and then
discharged, but rather runs off and dissipates in a natural and
unimpeded manner, is not a discharge from a point source as
defined by § 502(14). As we wrote in League of Wilderness
Defenders/Blue Mountains Biodiversity Project v. Forsgren,
309 F.3d 1181, 1184 (9th Cir. 2002):

Although nonpoint source pollution is not statutorily
defined, it is widely understood to be the type of pol-
lution that arises from many dispersed activities over
large areas, and is not traceable to any single discrete
source. Because it arises in such a diffuse way, it is
very difficult to regulate through individual permits.
The most common example of nonpoint source pol-
lution is the residue left on roadways by automo-
biles. Small amounts of rubber are worn off of the
tires of 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 non-
point 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).
 NEDC v. BROWN 6415
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 already-issued NPDES permit requiring
a state agency using storm drains “to control polluted storm-
water 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 eventually
passes through storm sewer systems and is thus subject to the
NPDES permit program.” In Trustees for Alaska v. EPA, 749
F.2d 549 (9th Cir. 1984), we explicitly agreed with a decision
of the Tenth Circuit, United States v. Earth Sciences, Inc., 599
F.2d 368 (10th Cir. 1978). We wrote:

The [Tenth Circuit] observed that Congress had clas-
sified nonpoint source pollution as runoff caused pri-
marily by rainfall around activities that employ or
create pollutants. Such runoff could not be traced to
any identifiable point of discharge. The court con-
cluded that point and nonpoint sources are not distin-
guished by the kind of pollution they create or by the
activity causing the pollution, but rather by whether
the pollution reaches the water through a confined,
discrete conveyance. Thus, when mining activities
release pollutants from a discernible conveyance,
they are subject to NPDES regulation, as are all
point sources.

749 F.2d at 558 (emphasis added) (internal citation omitted).
Finally, in Environmental Defense Center v. EPA, 344 F.3d
832 (9th Cir. 2003), we wrote: “Storm sewers are established
point sources subject to NPDES permitting requirements. . . .
Diffuse runoff, such as rainwater that is not channeled
through a point source, is considered nonpoint source pollu-
tion and is not subject to federal regulation.” Id. at 841, 842
n.8 (emphasis added) (internal citations omitted).
6416 NEDC v. BROWN
The clarity of the text of § 502(14), as well as our caselaw,
would ordinarily make recourse to legislative history unneces-
sary. The “unambiguously expressed intent of Congress” con-
trols. Chevron, 467 U.S. at 842-43. However, because EPA
relied on the legislative history of the FWPCA in promulgat-
ing the Silvicultural Rule at issue in this case, we recount
some of that history as background to our analysis of the
Rule.

The FWPCA established “distinctly different methods to
control pollution released from point sources and that trace-
able to nonpoint sources.” Pronsolino v. Nastri, 291 F.3d
1123, 1126 (9th Cir. 2002). The Senate Committee elected to
impose stringent permitting requirements only on point
sources because “[t]here is no effective way as yet, other than
land use control, by which you can intercept [nonpoint] runoff
and control it in the way that you do a point source. We have
not yet developed technology to deal with that kind of a prob-
lem.” 117 Cong. Rec. 38825 (Nov. 2, 1971) (statement of
Sen. Muskie).

The House and Senate committees made clear that the term
“point source” was not to be interpreted narrowly. “By the use
of the term ‘discharge of pollutants’ this provision [§ 402]
covers any addition of any pollutant to navigable waters from
any point source.” H.R. Rep. No. 92-911, at 125 (1971). The
Senate Committee Report instructed that

the [EPA] Administrator should not ignore dis-
charges resulting from point sources other than pipe-
lines or similar conduits. . . . There are many other
forms of periodic, though frequent, discharges of
pollutants into the water through point sources such
as barges, vessels, feedlots, trucks and other convey-
ances.

S. Rep. No. 92-414, at 51 (1971). Senator Dole explained his
understanding of the distinction as it related to the problem of
agricultural pollution:
 NEDC v. BROWN 6417
Most of the problems of agricultural pollution deal
with non-point sources. Very simply, a non-point
source of pollution is one that does not confine its
pollution discharge to one fairly specific outlet, such
as a sewer pipe, a drainage ditch or a conduit; thus,
a feed-lot would be considered to be a non-point
source as would pesticides and fertilizers.

S. Rep. No. 92-414, at 98-99 (1971) (Supplemental Views of
Sen. Dole).

Congress did not provide the EPA Administrator with dis-
cretion to define the statutory terms. Senator Randolph, the
Chairman of the Senate Committee, explained, “We have
written into law precise standards and definite guidelines on
how the environment should be protected. We have done
more than just provide broad directives [for] administrators to
follow.” 117 Cong. Rec. 38805 (Nov. 2, 1971). Senator Mus-
kie, another major proponent of the legislation, clarified that
EPA would provide “[g]uidance with respect to the identifica-
tion of ‘point sources’ and ‘nonpoint sources.’ ” 117 Cong.
Rec. 38816 (Nov. 2, 1971). However, “[i]f a man-made drain-
age, ditch, flushing system or other such device is involved
and if measurable waste results and is discharged into water,
it is considered a ‘point source.’ ” Id.

[4] Congress also sought to require permits for any activity
that met the legal definition of “point source,” regardless of
feasibility concerns. For example, Congressman Roncalio of
Wyoming proposed an amendment to exempt irrigated agri-
culture from the NPDES permit program because it was “vir-
tually impossible to trace pollutants to specific irrigation
lands, making these pollutants a nonpoint source in most
cases.” 118 Cong. Rec. 10765 (Mar. 29, 1972). Opponents
objected that the amendment would exclude large point
source polluters simply because the channeled water origi-
nally derived from irrigated agriculture. Congressman Waldie
explained:
6418 NEDC v. BROWN
In California there is a vast irrigation basin that
collects all the waste resident of irrigation water in
the Central Valley and places it in a drain— the San
Luis Draining—and transport[s] it several hundreds
of miles and then dumps it into the San Joaquin
River which flows into the estuary and then into San
Francisco Bay. It is highly polluted water that is
being dumped in waters already jeopardized by pol-
lution.

Will the gentleman’s amendment establish that as
a nonpoint source pollution or will it come under the
point source solution discharge?

Id. Congressman Roncalio responded that his amendment
would not require permitting for this type of activity — that
is, that it would redefine these agricultural point sources as
nonpoint source pollution. His amendment was then rejected
on the House floor. See id.

Congress eventually adopted a statutory exemption for
agricultural irrigation in 1977, five years after the passage of
the FWCPA. See CWA § 402(l), 33 U.S.C. § 1342(l) (“The
Administrator shall not require a permit under this section for
discharges composed entirely of return flows from irrigated
agriculture, nor shall the Administrator directly or indirectly,
require any State to require such a permit.”); CWA § 502(14),
33 U.S.C. § 1362(14) (“This term does not include return
flows from irrigated agriculture.”). Congress did so to allevi-
ate EPA’s burden in having to issue permits for every agricul-
tural point source. “The problems of permitting every discrete
source or conduit returning water to the streams from irrigated
lands is simply too burdensome to place on the resources of
EPA.” 123 Cong. Rec. 38956 (Dec. 15, 1977) (statement of
Rep. Roberts). Congress did not, however, grant EPA the dis-
cretion to exempt agricultural discharges from the general
statutory definition of point source discharges. Rather, Con-
gress exempted such discharges by amending the statute.
 NEDC v. BROWN 6419
Congress has never granted a similar statutory exemption for
silvicultural discharges from the general definition of point
source discharges.

Despite the foregoing, Defendants contend that stormwater
runoff from logging roads that is collected in a system of
ditches, culverts, and channels, and is then discharged into
streams and rivers, is a nonpoint source discharge. Defendants
contend that the Silvicultural Rule exempts such discharges
from the definition of point source discharge contained in
§ 502(14), and therefore from the NPDES permitting system.
Alternatively, Defendants contend that the 1987 amendments
to the CWA exempted such discharges from the permitting
system. We discuss defendants’ two contentions in turn.

B. The Silvicultural Rule

1. Adoption of the Rule

In 1973, one year after the passage of the FWPCA, EPA
promulgated regulations categorically exempting several
kinds of discharges from the NPDES permit program.
Exempted discharges included discharges from storm sewers
composed entirely of storm runoff uncontaminated by indus-
trial or commercial activity, discharges from relatively small
animal confinement facilities, discharges from silvicultural
activities, and irrigation return flow from point sources where
the flow was from less than 3000 acres. The exemption for
discharges from silvicultural activities provided:

The following do not require an NPDES permit:

...

(j) Discharges of pollutants from agricultural and
silvicultural activities, including irrigation return
flow and runoff from orchards, cultivated crops, pas-
6420 NEDC v. BROWN
tures, rangelands, and forest lands, except that this
exclusion shall not apply to the following:

...

(5) Discharges from any agricultural or
silvicultural activity which have been iden-
tified by the Regional Administrator of the
Director of the State water pollution control
agency or interstate agency as a significant
contributor of pollution.

40 C.F.R. § 125.4 (1975). The Natural Resources Defense
Council challenged the regulations as inconsistent with the
statute. See Natural Res. Def. Council v. Train, 396 F. Supp.
1393 (D.D.C. 1975).

EPA defended the challenged regulations on the ground
“that the exempted categories of sources are ones which fall
within the definition of point source but which are ill-suited
for inclusion in a permit program.” Id. at 1395. The district
court wrote that EPA has authority to clarify by regulation the
definition of nonpoint and point source discharges, but only
so long as its regulations comply with the statutory text. Id.
at 1395-96. In the court’s view, the challenged regulations
categorically exempted “entire classes of point sources from
the NPDES permit requirements.” Id. at 1396. The court
therefore held that the regulations were fatally inconsistent
with the definition contained in § 502(14), writing “that the
Administrator [of the EPA] cannot lawfully exempt point
sources discharging pollutants from regulation under
NPDES.” Id. at 1402.

EPA appealed to the D.C. Circuit. While the appeal was
pending, EPA grudgingly promulgated revised regulations.
For example, in soliciting public comment on a proposal for
a “system for separate agricultural and silvicultural storm
sewers” rule in December 1975, EPA wrote:
 NEDC v. BROWN 6421
In promulgating the [earlier] regulations EPA
stated its belief that while some point sources within
the excluded categories may be significant contribu-
tors of pollution which should be regulated consis-
tent with the purposes of the FWPCA, it would be
administratively difficult if not impossible, given
Federal and State resource levels, to issue individual
permits to all such point sources. . . . Essentially,
these [earlier] regulations providing for exemptions
were based on EPA’s view (a view which it contin-
ues to maintain is correct) that most sources within
the exempted categories present runoff-related prob-
lems not susceptible to the conventional NPDES per-
mit program including effluent limitations. EPA’s
position was and continues to be that most rainfall
runoff is more properly regulated under section 208
of the FWPCA [which does not require NPDES per-
mits], whether or not the rainfall happens to collect
before flowing into navigable waters. Agricultural
and silvicultural runoff, as well as runoff from city
streets, frequently flows into ditches or is collected
in pipes before discharging into streams. EPA con-
tends that most of these sources are nonpoint in
nature and should not be covered by the NPDES per-
mit program.

40 Fed. Reg. 56932 (Dec. 5, 1975) (emphasis added).

[5] Two months later, in February 1976, EPA proposed a
revised Silvicultural Rule and solicited public comment. EPA
wrote,

[T]he Agency has carefully examined the relation-
ship between the NPDES permit program (which is
designed to control and eliminate discharges of pol-
lutants from discrete point sources) and water pollu-
tion from silvicultural activities (which tends to
result from precipitation events). It has been deter-
6422 NEDC v. BROWN
mined that most water pollution related to silvicul-
tural activities is nonpoint in nature.

41 Fed. Reg. 6282 (Feb. 12, 1976).

EPA continued:

Those silvicultural activities which are specified
in the regulations (rock crushing, gravel washing,
log sorting and log storage facilities), and are thus
point sources, are subject to the NPDES permit pro-
gram. Only those silvicultural activities that, as a
result of controlled water used by a person, dis-
charge pollutants through a discernible, confined and
discrete conveyance into navigable waters are
required to obtain a § 402 pollution discharge per-
mit.

Id. This passage provides EPA’s central criterion for distin-
guishing between silvicultural point and nonpoint sources.
EPA proposed to characterize discharges of pollutants
through a discernible, confined and discrete conveyance as
point source discharges only when they were “a result of con-
trolled water used by a person.” Under this criterion, the pro-
posed rule named as point source discharges only those
related to “rock crushing, gravel washing, log sorting, [and]
log storage facilities.” Id. 6283 (Proposed Rule); 41 Fed. Reg.
24711 (Jun. 18, 1976) (Final Rule); 40 C.F.R. § 124.85
(1976). Any other silvicultural discharge of pollutants, even
if made through a discernible, confined and discrete convey-
ance, was considered a nonpoint source of pollutants. In
effect, this meant that any natural runoff containing pollutants
was not a point source, even if the runoff was channeled and
controlled through a “discernible, confined and discrete con-
veyance” and then discharged into navigable waters.

In its “response to comments” accompanying the final ver-
sion, EPA provided more general criteria by which to distin-
guish nonpoint from point sources of pollution. It wrote:
 NEDC v. BROWN 6423
Basically, nonpoint sources of water pollution are
identified by three characteristics:

(i) The pollutants discharged are induced by natu-
ral processes, including precipitation, seepage, per-
collation [sic], and runoff;

(ii) The pollutants discharged are not traceable to
any discrete or identifiable facility; and

(iii) The pollutants discharged are better con-
trolled through the utilization of best management
practices, including process and planning techniques.

In contrast to these criteria identifying nonpoint
sources, point sources of water pollution are gener-
ally characterized by discrete and confined convey-
ances from which discharges of pollutants into
navigable waters can be controlled by effluent limi-
tations. It is these point sources in the silviculture
category which are most amenable to control
through the NPDES permit program.

41 Fed. Reg. 24710 (Jun. 18, 1976). EPA specifically noted
that the single criterion for point sources—resulting from
“controlled water used by a person”— was underinclusive.
EPA pointed out that some point source discharges take place
“regardless of any [prior] contact with water,” such as dis-
charges of wood chips and bark directly into navigable water.
Id.

[6] However, the actual text of the final version of the Sil-
vicultural Rule was little changed from the version proposed
in February. See 41 Fed. Reg. 24711 (Jun. 18, 1976). The
revised Rule provided in pertinent part:

Silvicultural activities.
6424 NEDC v. BROWN
(a) Definitions. For the purpose of this section:

(1) The term “silvicultural point source” means
any discernible, confined and discrete conveyance
related to rock crushing, gravel washing, log sorting,
or log storage facilities which are operated in con-
nection with silvicultural activities and from which
pollutants are discharged into navigable waters of
the United States.

Comment: This term does not include nonpoint
source activities inherent to silviculture such as nur-
sery operations, site preparation, reforestation and
subsequent cultural treatment, thinning, prescribed
burning, pest and fire control, harvesting operations,
surface drainage, and road construction and mainte-
nance from which runoff results from precipitation
events.

40 C.F.R. § 124.85 (1976). Even though there was no longer
a single criterion for identifying point source discharges, the
same four activities were specified as producing point source
discharges—rock crushing, gravel washing, log sorting and
log storage. Id. And even though there were now three general
criteria for identifying nonpoint sources, the effect of the Rule
was to treat all natural runoff as nonpoint pollution, even if
channeled and discharged through a discernible, confined and
discrete conveyance.

In comments accompanying the proposed Silvicultural Rule
in February 1976, EPA provided, in concise form, its justifi-
cation for the Rule. It wrote:

Technically, a point source is defined as a “discern-
ible, confined and discrete conveyance, including but
not limited to any pipe, ditch [or] channel * * *”
(§ 502(14) of the FWPCA) and includes all such
conveyances. However, a proper interpretation of the
 NEDC v. BROWN 6425
FWPCA as explained in the legislative history and
supported by the [district] court in NRDC v. Train is
that not every “ditch, water bar or culvert” is “means
[sic] to be a point source under the Act [FWCPA].”
It is evident, therefore, that ditches, pipes and drains
that serve only to channel, direct, and convey non-
point runoff from precipitation are not meant to be
subject to the § 402 permit program.

41 Fed. Reg. 6282 (Feb. 12, 1976). A sentence-by-sentence
analysis shows the weakness of EPA’s justification.

In the first sentence, EPA wrote that “[t]echnically, a point
source is defined as a ‘confined and discrete conveyance,
including but not limited to any pipe, ditch, [or] channel.’ ”
The words quoted by EPA in this sentence were a direct
(though partial) quotation of the statutory definition of “point
source” contained in § 502(14) of the FWPCA. EPA’s choice
of the word “technically” is somewhat odd and even mislead-
ing; perhaps EPA hoped that the word would diminish the
force of the statutory definition. But whatever its motive, EPA
would have been more accurate if it had written “textually”
instead of “technically.”

In the second sentence, EPA wrote that “a proper interpre-
tation of the FWCPA as explained in the legislative history
and supported by the court in NRDC v. Train is that not every
‘ditch, water bar or culvert’ is ‘mean[t] to be a point source
under the Act [FWCPA].’ ” EPA was putting words into the
district court’s mouth. The district court did not hold that “not
every ‘ditch, water bar or culvert’ is ‘meant to be a point
source.’ ” Rather, the court wrote only that the plaintiff in the
case, NRDC, had not made that argument. See Train, 396 F.
Supp. at 1401 (“NRDC does not contend that every farm
ditch, water bar, or culvert on a logging road is properly
meant to be a point source under the Act.”). Further, and more
important, everyone understands that a “ditch, water bar or
culvert” that does not discharge into navigable waters is not
6426 NEDC v. BROWN
a point source. But the regulation does not exempt only such
ditches, water bars or culverts. Instead, it categorically
exempts collected runoff from silviculture, whether or not
there is a discharge into navigable waters.

[7] Finally, in the last sentence EPA wrote, “It is evident,
therefore, that ditches, pipes and drains that serve only to
channel, direct, and convey nonpoint runoff from precipita-
tion are not meant to be subject to the § 402 permit program.”
The text of § 502(14), quoted in the first sentence of the para-
graph, is flatly inconsistent with this statement. Under
§ 502(14), a pollutant comes from a point source if it is col-
lected and discharged through ditches, pipes, channels, and
similar conveyances. Section 502(14) says nothing, either
explicitly or implicitly, about the source of the water con-
tained in the discharge. Further, even though not every “ditch,
water bar, or culvert” is a point source within the meaning of
the statute, it hardly follows that a system of ditches, pipes
and channels that collects “controlled water used by a person”
and discharges it into a river is a point source, while an identi-
cal system that collects and discharges natural precipitation is
not.

[8] After EPA promulgated the revised Silvicultural Rule,
the Court of Appeals for the D.C. Circuit affirmed the district
court’s disapproval of the 1973 regulations, including the
original Silvicultural Rule. Natural Res. Def. Council v.
Costle, 568 F.2d 1369 (D.C. Cir. 1977). The court did not
review the revised Silvicultural Rule promulgated in 1976.
The court held that EPA did not have the authority categori-
cally to exempt point source discharges. It wrote:

Under the EPA’s interpretation the Administrator
would have broad discretion to exempt large classes
of point sources from any or all requirements of the
FWCPA. This is a result that the legislators did not
intend. Rather they stressed that the FWCPA was a
 NEDC v. BROWN 6427
tough law that relied on explicit mandates to a
degree uncommon in legislation of this type.

Id. at 1375.

The court responded to EPA’s argument that a literal inter-
pretation of the FWCPA’s definition of “point source” “would
place unmanageable burdens on the EPA”:

There are innumerable references in the legislative
history to the effect that the Act is founded on the
“basic premise that a discharge of pollutants without
a permit is unlawful and that discharges not in com-
pliance with the limitations and conditions for a per-
mit are unlawful.” Even when infeasibility
arguments were squarely raised, the legislature
declined to abandon the permit requirement.

Id. at 1375-76 (emphasis added). The court concluded:

The wording of the statute, legislative history, and
precedents are clear: the EPA Administrator does not
have authority to exempt categories of point sources
from the permit requirements of § 402. Courts may
not manufacture for an agency a revisory power
inconsistent with the clear intent of the relevant stat-
ute.

Id. at 1377.

[9] Although the D.C. Circuit did not address the revised
Silvicultural Rule in its opinion, its reasoning is no less appli-
cable to the new version of the Rule. The court concluded that
EPA does not have the authority to “exempt categories of
point sources” from the permitting requirements of § 402.
This is so even if EPA contends that the literal terms of the
statute would place “unmanageable burdens” on the agency.
6428 NEDC v. BROWN
The FWCPA was a “tough law” that EPA was not at liberty
to ignore.

2. The Revised Silvicultural Rule

The current text of the revised version of the Silvicultural
Rule is different in only minor respects from the version pro-
mulgated in 1976. In pertinent part, the current version pro-
vides:

(b) Definitions. (1) “Silvicultural point source”
means any discernible, confined and discrete con-
veyance related to rock crushing, gravel washing,
log sorting, or log storage facilities which are oper-
ated in connection with silvicultural activities and
from which pollutants are discharged into waters of
the United States. The term does not include non-
point source silvicultural activities such as nursery
operations, site preparation, reforestation and subse-
quent cultural treatment, thinning, prescribed burn-
ing, pest and fire control, harvesting operations,
surface drainage, or road construction and mainte-
nance from which there is natural runoff.

40 C.F.R. § 122.27.

The text of the CWA distinguishes between point and non-
point sources depending on whether the pollutant is channeled
and controlled through a “discernible, confined and discrete
conveyance.” CWA § 502(14), 33 U.S.C. § 1362(14). The
Silvicultural Rule, by contrast, categorically distinguishes
between the two types of discharges depending on the source
of the pollutant. Under the Rule, “silvicultural point source”
discharges are those discharged through “discernible, con-
fined and discrete conveyance[s],” but only when they are
direct discharges of wood chips, bark, and the like, or dis-
charges resulting from “controlled water used by a person.”
See 41 Fed. Reg. 24710 (Jun. 18, 1976); 41 Fed. Reg. 6282
 NEDC v. BROWN 6429
(Feb. 12, 1976). All other discharges of “natural runoff” are
nonpoint sources of pollution, even if such discharges are
channeled and controlled through a “discernible, confined and
discrete conveyance.”

A nonexhaustive list of silvicultural point source discharges
under the Rule includes discharges “related to rock crushing,
gravel washing, log sorting, [and] log storage facilities.” A
nonexhaustive list of silvicultural nonpoint sources of pollu-
tion under the Rule includes “silvicultural activities such as
nursery operations, site preparation, reforestation and subse-
quent cultural treatment, thinning, prescribed burning, pest
and fire control, harvesting operations, surface drainage, or
road construction and maintenance.”

[10] The original Silvicultural Rule, which was struck
down by the district court in Train and on appeal in Costle,
categorically exempted all discharges from silvicultural activ-
ities. The current Rule categorically exempts all discharges
from silvicultural activities resulting from natural runoff. The
categorical exemption in the current Rule is somewhat smaller
than the exemption in the original Rule, but it is a categorical
exemption nonetheless. Indeed, in a later rulemaking proposal
EPA specifically characterized it as a categorical exemption.
See 64 Fed. Reg. 46058, 46077 (Aug. 23, 1999) (“Currently,
runoff from [the list of “non-point source silvicultural activi-
ties”] is categorically excluded from the NPDES program.”).
The question before us is whether the categorical exemption
from the NPDES permit program in the current Rule is based
on a permissible interpretation of § 502(14).

We have dealt with the Silvicultural Rule once before. In
League of Wilderness Defenders/Blue Mountain Diversity
Project v. Forsgren (“Forsgren”), 309 F.3d 1181 (9th Cir.
2002), several environmental groups sued to enjoin unpermit-
ted aerial spraying of insecticide to combat the Douglas Fir
Tussock Moth. Some of the insecticide was sprayed onto the
surface of streams. Plaintiffs contended that the aerial spray-
6430 NEDC v. BROWN
ing was a discharge from a point source requiring an NPDES
permit. Relying on the Silvicultural Rule and on two letters
and a guidance document from EPA, the Forest Service took
the position that the spraying was not a point source dis-
charge, and that a permit was therefore not required. We dis-
agreed with EPA and the Forest Service.

The core of the EPA and Forest Service argument was that
“pest . . . control” was one of the activities listed in the Silvi-
cultural Rule as not constituting a point source discharge. We
wrote:

The Forest Service’s argument fails because the stat-
ute itself is clear and unambiguous. The statutory
definition of point source, “any discernible, confined
and discrete conveyance, including but not limited to
any . . . vessel,” 33 U.S.C. § 1362(14), clearly
encompasses an aircraft equipped with tanks spray-
ing pesticide from mechanical sprayers directly over
covered waters. The Forest Service cannot contra-
vene the will of Congress through its reading of
administrative regulations.

Forsgren, 309 F.3d at 1185-86.

We pointed out that the Rule characterized a pest control
discharge as nonpoint only when it was “silvicultural pest
control from which there is natural runoff.” Id. at 1186
(emphasis in original). If pest control activity resulted in natu-
ral runoff, that runoff was not a point source discharge under
§ 502(14). But it was undisputed in Forsgren that aerial
spraying of pesticide into streams was not “natural runoff.”
We had no occasion to rule on, and did not discuss, whether
silvicultural activities from which there is natural runoff that
is channeled, controlled, and discharged through a “discern-
ible, confined and discrete conveyance” is a point source
under § 502(14).
 NEDC v. BROWN 6431
[11] We emphatically “reject[ed] the Forest Service’s
argument that the EPA has the authority to ‘refine’ the defini-
tions of point source and nonpoint source pollution in a way
that contravenes the clear intent of Congress as expressed in
the statute.” Id. at 1190. We wrote:

We agree with the D.C. Circuit that the EPA has
some power to define point source and nonpoint
source pollution where there is room for reasonable
interpretation of the statutory definition. However,
the EPA may not exempt from NPDES permit
requirements that which clearly meets the statutory
definition of a point source by “defining” it as a non-
point source. Allowing the EPA to contravene the
intent of Congress, by simply substituting the word
“define” for the word “exempt,” would turn Costle
on its head.

Id. We now reach the question not reached or discussed in
Forsgren — whether discharge of natural runoff becomes a
point source discharge when it is channeled and controlled
through a “discernible, confined and discrete conveyance” in
a system of ditches, culverts, and channels. We conclude that
it does.

[12] In our view, the answer to the question before us is as
clear as the answer to the questions presented in Costle and
in Forsgren. The CWA prohibits “the discharge of any pollu-
tant by any person” without an NPDES permit. 33 U.S.C.
§ 1311(a). The term “discharge of a pollutant” means “any
addition of any pollutant to navigable waters from any point
source.” 33 U.S.C. § 1362(12)(A) (emphasis added). A “point
source” is

any discernible, confined and discrete conveyance,
including but not limited to any pipe, ditch, channel,
tunnel, conduit, well, discrete fissure, container, roll-
ing stock, concentrated animal feeding operation, or
6432 NEDC v. BROWN
vessel or other floating craft, from which pollutants
are or may be discharged.

33 U.S.C. § 1362(14). The definition in no way depends on
the manner in which the pollutant arrives at the “discernible,
confined and discrete conveyance.” That is, it makes no dif-
ference whether the pollutant arrives as the result of “con-
trolled water used by a person” or through natural runoff.

We agree with the analysis of the district court in Environ-
mental Protection Information Center v. Pacific Lumber Co.
(“EPIC”), 2003 WL 25506817 (N.D. Cal.). Relying on Fors-
gren, Judge Patel concluded that stormwater runoff from log-
ging roads that was collected in a system of ditches, culverts,
and channels, and then discharged into protected water, was
a point source discharge requiring an NPDES permit. After an
extensive analysis, the district court wrote:

The water runoff system this action addresses is an
elaborate and extensive one. Blending a variety of
drainage methods, the system covers a substantial
amount of land and addresses a significant amount of
water. Where this runoff system involves “surface
drainage[ ] or road construction from which there is
natural runoff,” section 122.27 [the Silvicultural
Rule] may control. But where the system utilizes the
kind of conduits and channels embraced by section
502(14), section 122.27 does not control: It cannot
control, for one, because section 502(14) of the
CWA trumps section 122.27’s operation, as EPA
may not alter the definition of an existing “point
source.” And it cannot control, for another, because
section 122.27’s own terms are unsatisfied; once
runoff enters a conduit like those listed in section
502(14), the runoff ceases to be the kind of “natural
runoff” section 122.27 expressly targets. In this latter
context, section 122.27 does not—and cannot—
 NEDC v. BROWN 6433
absolve silvicultural businesses of CWA’s “point
source” requirements.

Id. at *15 (internal citations omitted).

As pointed out by the district court in EPIC, there are two
possible readings of the Silvicultural Rule. The first reading
reflects the intent of EPA in adopting the Rule. Under this
reading, the Rule exempts all natural runoff from silvicultural
activities such as nursery operations, site preparation, and the
other listed activities from the definition of point source, irre-
spective of whether, and the manner in which, the runoff is
collected, channeled, and discharged into protected water. If
the Rule is read in this fashion, it is inconsistent with
§ 502(14) and is, to that extent, invalid.

[13] The second reading does not reflect the intent of EPA,
but would allow us to construe the Rule to be consistent with
the statute. Under this reading, the Rule exempts natural run-
off from silvicultural activities such as those listed, but only
as long as the “natural runoff” remains natural. That is, the
exemption ceases to exist as soon as the natural runoff is
channeled and controlled in some systematic way through a
“discernible, confined and discrete conveyance” and dis-
charged into the waters of the United States.

[14] Under either reading, we hold that the Silvicultural
Rule does not exempt from the definition of point source dis-
charge under § 512(14) stormwater runoff from logging roads
that is collected and channeled in a system of ditches, cul-
verts, and conduits before being discharged into streams and
rivers.

C. 1987 Amendments to the CWA

Defendants contend in the alternative that even if the dis-
charges from a system of ditches, culverts, and channels are
point source discharges within the meaning of § 502(14), and
6434 NEDC v. BROWN
even if the Silvicultural Rule does not exempt such discharges
from § 502(14), the discharges are nonetheless exempt from
the permitting process because of the 1987 amendments to the
CWA. Defendants made this contention in the district court,
but that court did not decide the question.

We can affirm the decision of the district court on any
ground supported by the record, even one not relied on by that
court. Thompson v. Paul, 547 F.3d 1055, 1058-59 (9th Cir.
2008). Defendants urge us, if we hold that the Silvicultural
Rule does not exempt the discharges, to affirm the district
court based on the 1987 amendments. No factual development
is necessary given that the district court dismissed under Rule
12(b)(6). The parties have briefed the question in this court.
We therefore reach the question.

1. Congressional Approval or Acquiescence

As a threshold matter, we consider whether, in adopting the
1987 amendments to the CWA, Congress sub silentio
approved of, or acquiesced in, the Silvicultural Rule. We con-
clude that Congress did not.

In some instances, congressional re-enactment of statutes
can be persuasive evidence of approval of longstanding
administrative regulations promulgated under that statute. In
NLRB v. Bell Aerospace Co., 416 U.S. 267, 274-75 (1974),
the Court wrote, “[A] court may accord great weight to the
longstanding interpretation placed on a statute by an agency
charged with its administration. This is especially so where
Congress has re-enacted the statute without pertinent change.
In these circumstances, congressional failure to revise or
repeal the agency’s interpretation is persuasive evidence that
the interpretation is the one intended by Congress.” See also
Commodity Futures Trading Comm’n v. Schor, 478 U.S. 833,
846 (1986) (quoting and paraphrasing Bell Aerospace). But
this case is very different from Bell Aerospace and Schor.
First, in both Bell Aerospace and Schor, the legislative histo-
 NEDC v. BROWN 6435
ries made clear that when Congress re-enacted the statutes at
issue it was well aware of the existing administrative interpre-
tation of the statutes. Here, by contrast, there is no indication
that Congress was aware of the Silvicultural Rule when it
adopted the 1987 amendments. There is no mention of, or
even allusion to, the Rule anywhere in the legislative history
of the amendments. Second, in both Bell Aerospace and
Schor, the relevant portions of the statutes at issue were re-
enacted essentially without change. Here, as we explain
below, the 1987 amendments fundamentally changed the stat-
utory treatment of stormwater discharges. Third, the language
of the original and the re-enacted statutes in both Bell Aero-
space and Schor was readily susceptible to the administrative
interpretations of those statutes. Here, by contrast, the rele-
vant statutory language is flatly inconsistent with the Silvicul-
tural Rule.

In other instances, congressional action or inaction can con-
stitute acquiescence in an existing regulation. The Supreme
Court has cautioned strongly against finding congressional
acquiescence. In Solid Waste Agency of Northern Cook
County v. U.S. Army Corps of Engineers, 531 U.S. 159, 162
(2001), it wrote, “Although we have recognized congressional
acquiescence to administrative interpretations of a statute in
some circumstances, we have done so with extreme care.”
After discussing a case in which there had been congressional
hearings on the precise issue, and in which thirteen bills had
been introduced in unsuccessful attempts to overturn the regu-
lation, the Court wrote, “Absent such overwhelming evidence
of acquiescence, we are loath to replace the plain text and
original understanding of a statute with an amended agency
interpretation.” Id. at 169-70, n.5. Here, there is no evidence
whatsoever of congressional acquiescence in the Silvicultural
Rule, let alone “overwhelming evidence.”

2. The 1987 Stormwater Amendments

[15] Congress amended the CWA in 1987 to deal specifi-
cally with stormwater discharges. Pub. L. No. 100-4, 101 Stat.
6436 NEDC v. BROWN
7 (1987). Congress added § 402(p) to the CWA, establishing
a “phased and tiered approach” to NPDES permitting of
stormwater discharges. See 55 Fed. Reg. 47994 (Nov. 16,
1990) (describing 33 U.S.C. § 1342(p)). Section 402(p) fun-
damentally redesigned the CWA’s approach to stormwater
discharges.

Under the framework created by the FWCPA in 1972, EPA
was required to establish a permitting system for all point
source discharges of stormwater. Senator Durenberger
explained that the Conference Bill that would become the
1987 amendment focused on stormwater point sources.

The [FWPCA] of 1972 required all point sources,
including stormwater dischargers, to apply for
NPDES permits within 180 days of enactment by
1973. Despite this clear directive, EPA has failed to
require most stormwater point sources to apply for
permits which would control the pollutants in their
discharge.

132 Cong. Rec. 32380, 32400 (Oct. 16, 1986). Senator Staf-
ford, the Chairman of the Committee on Environment and
Public Works reiterated, “EPA should have developed this
[stormwater] program long ago. Unfortunately, it did not.”
132 Cong. Rec. 32381 (Oct. 16, 1986).

Congress recognized that EPA’s difficulties stemmed in
part from the large number of stormwater sources falling
within the definition of a point source. See, e.g., 131 Cong.
Rec. 19846, 19850 (Jul. 22, 1985) (statement of Rep. Row-
land) (“Under existing law, the [EPA] must require [NPDES]
permits for anyone who has stormwater runoff on their prop-
erty. What we are talking about is potentially thousands of
permits for churches, schools, residential property, runoff that
poses no environmental threat[.]”); 131 Cong. Rec. 15616,
15657 (Jun. 13, 1985) (Statement of Sen. Wallop) (“[EPA
regulations] can be interpreted to require everyone who has a
 NEDC v. BROWN 6437
device to divert, gather, or collect stormwater runoff and
snowmelt to get a permit from EPA as a point source. . . .
Requiring a permit for these kinds of stormwater runoff con-
veyance systems would be an administrative nightmare.”).

In § 402(p), adopted as part of the 1987 amendments, Con-
gress required NPDES permits for the most significant
sources of stormwater pollution under so-called “Phase I” reg-
ulations. See 133 Cong. Rec. 983, 1006 (Jan. 8, 1987) (state-
ment of Rep. Roe) (“[Section 402(p)] establishes an orderly
procedure which will enable the major contributors of pollu-
tants to be addressed first, and all discharges to be ultimately
addressed in a manner which will not completely overwhelm
EPA’s capabilities.”). Section 402(p) lists five categories of
stormwater discharges, including discharges “associated with
industrial activity,” that are covered in Phase I. 33 U.S.C.
§ 1342(p)(2)(B). NPDES permits are required for all five cat-
egories of discharges. Id. §§ 1342(p)(1)-(2). A permit was
required for such discharges by 1990. Id. § 1342(p)(4)(A).

All remaining stormwater discharges are to be covered by
“Phase II” regulations. During Phase II, EPA is to study
stormwater discharges not covered by Phase I and to issue
regulations based on its study. Id. § 1342(p)(5)-(6). In 1999,
EPA promulgated a Phase II regulation requiring NPDES per-
mits for discharges from small municipal storm systems and
small construction sites. We upheld most of that regulation in
Environmental Defense Center v. EPA, 344 F.3d 832 (9th Cir.
2003), and remanded for further proceedings. EPA has not yet
responded to the remand.

Stormwater discharges from churches, schools and residen-
tial properties, through rain gutters or otherwise, and from
other relatively de minimus sources, are covered under Phase
II rather than Phase I. It is within the discretion of EPA to
promulgate Phase II regulations requiring, or not requiring,
permits for such discharges.
6438 NEDC v. BROWN
3. Phase I Stormwater Regulations

In 1990, EPA promulgated “Phase I” regulations for the
storm water discharges specified in § 402(p). 55 Fed. Reg.
47990 (Nov. 16, 1990); 40 C.F.R. § 122.26. For discharges
“associated with industrial activity,” which require NPDES
permits, EPA’s regulations provide:

Storm water discharge associated with industrial
activity means the discharge from any conveyance
that is used for collecting and conveying storm water
and that is directly related to manufacturing, process-
ing or raw materials storage areas at an industrial
plant. The term does not include discharges from
facilities or activities excluded from the NPDES pro-
gram under this part 122.

40 C.F.R. § 122.26(b)(14). The last sentence of this regulation
refers to the Silvicultural Rule, thereby purporting to exempt
from the definition of “discharges associated with industrial
activity” any activity that is defined as a nonpoint source in
the Silvicultural Rule. See id.

The preamble to the Phase I regulations makes clear EPA’s
intent to exempt nonpoint sources as defined in the Silvicul-
tural Rule from the permitting program mandated by § 402(p).
The preamble provides:

The definition of discharge associated with industrial
activity does not include activities or facilities that
are currently exempt from permitting under NPDES.
EPA does not intend to change the scope of 40 CFR
122.27 in this rulemaking. Accordingly, the defini-
tion of “storm water discharge associated with indus-
trial activity” does not include sources . . . which are
excluded under 40 CFR 122.27.

55 Fed. Reg. 47990, 48011 (Nov. 16, 1990).
 NEDC v. BROWN 6439
[16] In the 1987 amendments, Congress exempted many
stormwater discharges from the NPDES permitting process.
However, Congress made clear in § 402(p) that it did not
exempt “discharges associated with industrial activity.” 33
U.S.C. § 1342(p)(2)(B). Indeed, Congress specifically man-
dated that EPA establish a permitting process for such dis-
charges. See 33 U.S.C. § 1342(p)(4)(A) (“[T]he Administrator
shall establish regulations setting forth the permit application
requirements for stormwater discharges described in para-
graphs (2)(B) [“discharge[s] associated with industrial activi-
ty”] and (2)(C).” (emphasis added)). In NRDC v. EPA, 966
F.2d 1292 (9th Cir. 1992), we struck down a part of EPA’s
Phase I regulations exempting point source discharges from
construction sites of less than five acres. We wrote, “[I]f con-
struction activity is industrial in nature, and EPA concedes
that it is, EPA is not free to create exemptions from permitting
requirements for such activity.” Id. at 1306. Similarly, if silvi-
cultural activity is “industrial in nature,” § 402(p) requires
that discharges from such activity obtain NPDES permits.

[17] Industries covered by the Phase I “associated with
industrial activity” regulation are defined in accordance with
Standard Industrial Classifications (“SIC”). The applicable
(and unchallenged) regulation provides that facilities classi-
fied as SIC 24 are among “those considered to be engaging
in ‘industrial activity.’ ” 40 C.F.R. § 122.26(b)(14)(ii). It is
undisputed that “logging,” which is covered under SIC 2411
(part of SIC 24), is an “industrial activity.” SIC 2411 defines
“logging” as “[e]stablishments primarily engaged in cutting
timber and in producing . . . primary forest or wood raw mate-
rials . . . in the field.”

The regulation further defines the term “stormwater dis-
charge associated with industrial activity” as follows:

For the categories of industries identified in this sec-
tion, the term includes, but is not limited to, storm
water discharges from industrial plant yards; imme-
6440 NEDC v. BROWN
diate access roads and rail lines used or traveled by
carriers of raw materials, manufactured products,
waste material, or by-products used or created by
the facility; material handling sites; . . . .

40 C.F.R. § 122.26(b)(14)(ii) (emphasis added).

The Timber Defendants contend that logging roads are not
“immediate access roads” because they are not confined to the
immediate area of the site where the logging takes place. We
disagree. The Timber Defendants misunderstand the meaning
of the term “immediate” as it is used in the regulations. The
preamble to the Phase I regulations provides that “immediate
access roads” means “roads which are exclusively or primar-
ily dedicated for use by the industrial facility.” 55 Fed. Reg.
47990, 48009 (Nov. 16, 1990).

The Timber Defendants also contend that logging roads are
not “primarily dedicated” for use by the logging companies.
Again, we disagree. We recognize that logging roads are often
used for recreation, but that is not their primary use. Logging
companies build and maintain the roads and their drainage
systems pursuant to contracts with the State. Logging is also
the roads’ sine qua non: If there were no logging, there would
be no logging roads.

Finally, the Timber Defendants contend that, even if the
logging industry is classified by the Phase I rule and SIC 2411
as industrial, the logging sites are not “industrial facilities”
because they are not typical industrial plants. Therefore,
according to the Timber Defendants, any roads serving log-
ging sites cannot be the “immediate access roads” covered by
this rule. We continue to disagree. The definition of a “facili-
ty” engaging in “industrial activity” is very broad. The appli-
cable Phase I rule provides that many industrial facilities
beyond traditional industrial plants “are considered to be
engaging in ‘industrial activity,’ ” including mines, landfills,
 NEDC v. BROWN 6441
junkyards, and construction sites. 40 C.F.R.
§ 122.26(b)(14)(iii), (v), (x).

EPA’s comments to the Phase I rules explain the breadth of
the definition:

In describing the scope of the term “associated with
industrial activity”, several members of Congress
explained in the legislative history that the term
applied if a discharge was “directly related to manu-
facturing, processing or raw materials storage areas
at an industrial plant.”

55 Fed. Reg. at 48007. However, EPA stated that it was not
limiting the coverage of the rule to discharges referenced in
this legislative history. It explained:

Today’s rule clarifies the regulatory definition of
“associated with industrial activity” by adopting the
language used in the legislative history and supple-
menting it with a description of various types of
areas that are directly related to an industrial process
(e.g., industrial plant yards, immediate access roads
and rail lines, drainage ponds, material handling
sites, sites used for the application or disposal of pro-
cess waters, sites used for the storage and mainte-
nance of material handling equipment, and known
sites that are presently or have been in the past used
for residual treatment, storage or disposal).

Id.

[18] We therefore hold that the 1987 amendments to the
CWA do not exempt from the NPDES permitting process
stormwater runoff from logging roads that is collected in a
system of ditches, culverts, and channels, and is then dis-
charged into streams and rivers. This collected runoff consti-
tutes a point source discharge of stormwater “associated with
6442 NEDC v. BROWN
industrial activity” under the terms of § 502(14) and § 402(p).
Such a discharge requires an NPDES permit. As we explained
in NRDC v. EPA, 966 F.2d at 1306, “if [logging] activity is
industrial in nature, and EPA concedes that it is [see SIC
2411], EPA is not free to create exemptions from permitting
requirements for such activity.” The reference to the Silvicul-
tural Rule in 40 C.F.R. § 122.26(b)(14) does not, indeed can-
not, exempt such discharges from EPA’s Phase I regulations
requiring permits for discharges “associated with industrial
activity.”

4. Effect of Remand in Environmental Defense Center,
Inc. v. EPA

In Environmental Defense Center, 344 F.3d at 863, in 2003
we remanded to EPA a portion of its Phase II stormwater reg-
ulations to allow EPA to consider, inter alia, whether storm-
water discharges from logging roads should be included in
Phase II regulations. Amicus United States suggests that we
delay ruling on the question whether stormwater discharges
from logging roads must obtain permits under § 402(p) —
that is, under Phase I regulations — until EPA has responded
to the remand. We have just held that § 402(p) provides that
stormwater runoff from logging roads that is collected in a
system of ditches, culverts, and channels is a “discharge asso-
ciated with industrial activity,” and that such a discharge is
subject to the NPDES permitting process under Phase I.
Whether EPA might, or might not, provide further regulation
of stormwater runoff from logging roads in its Phase II regu-
lations does not reduce its statutory obligation under § 402(p).
We therefore see no reason to wait for EPA’s action in
response to our remand in Environmental Defense Center.

D. Summary

In some respects, we are sympathetic with EPA. When the
FWCPA was passed in 1972, EPA was faced with a near-
impossible task. The breadth of the definition of point source
 NEDC v. BROWN 6443
discharge contained in § 502(14) meant that EPA was sud-
denly required to establish an administrative system under
which enormous numbers of discharges would be subject to
a new and untested permitting process. Faced with this task,
EPA exempted several large categories of point source dis-
charges from the process in order to avoid the burden imposed
by the breadth of the definition contained in § 502(14).

Recognizing the burden on EPA, as well as on some of the
entities subject to the NPDES permitting requirement, Con-
gress subsequently narrowed the definition of point source
discharge by providing specific statutory exemptions for cer-
tain categories of discharges. For example, in 1977, Congress
exempted return flows from irrigated agriculture to alleviate
the EPA’s burden in having to permit “every source or con-
duit returning water to the streams from irrigated lands,”
which was what the text of the statute had required. 123
Cong. Rec. 38949, 38956 (Dec. 15, 1977) (Statement of Rep.
Roberts); see CWA §§ 402(l), 502(14), 33 U.S.C. §§ 1341(l),
1362(14). Then in 1987, ten years later, Congress comprehen-
sively revised stormwater regulation. It did so in part because
the existing broad definition of point source discharge risked
creating an “administrative nightmare” for the EPA. 131
Cong. Rec. 15616, 15657 (Jun. 13, 1985) (Statement of Sen.
Wallop). It also did so in part because under the existing defi-
nition a vast number of de minimus stormwater sources, many
of which posed no environmental threat, required NPDES
permits. As part of the 1987 amendments, Congress enacted
§ 402(p), which gives discretion to EPA to exclude from the
permitting process de minimus sources of stormwater pollu-
tion.

However, in cases where Congress has not provided statu-
tory exemptions from the definition of point source, federal
courts have invalidated EPA regulations that categorically
exempt discharges included in the definition of point source
discharge contained in § 502(14). The most directly relevant
example is Costle, in which the D.C. Circuit invalidated the
6444 NEDC v. BROWN
original version of the Silvicultural Rule which had exempted
all discharges from silvicultural activities. Other examples
include National Cotton Council of America v. EPA, 553 F.3d
927, 940 (6th Cir. 2009) (invalidating EPA rule exempting
pesticide residue from permitting requirements because “the
statutory text of the Clean Water Act forecloses the EPA’s
Final Rule”); Northern Plains Resource Council v. Fidelity
Exploration and Development Co., 325 F.3d 1155, 1164 &
n.4 (9th Cir. 2003) (refusing to grant deference to EPA’s
approval of Montana’s permitting program that exempted
groundwater pollutants from permitting requirements because
“[o]nly Congress may amend the CWA to create exemptions
from regulation”); NRDC v. EPA, 966 F.2d 1292, 1304-06
(9th Cir. 1992) (holding arbitrary and capricious EPA rule
exempting various types of light industry and construction
sites of less than five acres from permitting requirements).
Not all examples involve invalidation of recently promulgated
regulations. In Northwest Environmental Advocates v. EPA,
537 F.3d 1006 (9th Cir. 2008), we invalidated an EPA regula-
tion that exempted sewage discharges from vessels from the
permitting process. In that case, the invalidated EPA regula-
tion had been on the books since 1973.

Congress intentionally passed a “tough law.” Costle, 568
F.2d at 1375. But Congress did not intend that the law impose
an unreasonable or impossible burden. Congress has carefully
exempted certain categories of point source discharges from
the statutory definition. For those discharges that continue to
be covered by the definition, the permitting process is not
necessarily onerous, either for EPA or for an entity seeking a
permit. For example, in appropriate circumstances a discharge
may be allowed under a “general permit” requiring only that
the discharger submit a “notice of intent” to make the dis-
charge. As we explained in Natural Resources Defense Coun-
cil v. EPA, 279 F.3d 1180, 1183 (9th Cir. 2002):

NPDES permits come in two varieties: individual
and general. An individual permit authorizes a spe-
 NEDC v. BROWN 6445
cific entity to discharge a pollutant in a specific
place and is issued after an informal agency adjudi-
cation process. See 40 C.F.R. §§ 122.21, 124.1-
124.21, 124.51-124.66. General permits, on the other
hand, are issued for an entire class of hypothetical
dischargers in a given geographical region and are
issued pursuant to administrative rulemaking proce-
dures. See id. §§ 122.28, 124.19(a). General permits
may appropriately be issued when the dischargers in
the geographical area to be covered by the permit are
relatively homogenous. See id. § 122.28(a)(2). After
a general permit has been issued, an entity that
believes it is covered by the general permit submits
a “notice of intent” to discharge pursuant to the gen-
eral permit. Id. § 122.28(b)(2). A general permit can
allow discharging to commence upon receipt of the
notice of intent, after a waiting period, or after the
permit issuer sends out a response agreeing that the
discharger is covered by the general permit. Id.
§ 122.28(b)(2)(iv).

Until now, EPA has acted on the assumption that NPDES
permits are not required for discharges of pollutants from
ditches, culverts, and channels that collect stormwater runoff
from logging roads. EPA has therefore not had occasion to
establish a permitting process for such discharges. But we are
confident, given the closely analogous NPDES permitting
process for stormwater runoff from other kinds of roads, that
EPA will be able to do so effectively and relatively expedi-
tiously.

Conclusion

For the foregoing reasons, we conclude that stormwater
runoff from logging roads that is collected by and then dis-
charged from a system of ditches, culverts, and channels is a
point source discharge for which an NPDES permit is
required.
6446 NEDC v. BROWN
We therefore REVERSE the district court’s grant of
Defendants’ motion to dismiss, and we REMAND to the dis-
trict court for further proceedings consistent with this opinion.