No. 19-592
In the Supreme Court of the United States
__________________
COUNTY COMMISSIONERS OF CARROLL COUNTY, MARYLAND,
Petitioner,
v.
MARYLAND DEPARTMENT OF THE ENVIRONMENT,
Respondent.
__________________
On Petition for Writ of Certiorari to the
Court of Appeals of Maryland

__________________

AMICI CURIAE THE NATIONAL ASSOCIATION OF CLEAN
WATER AGENCIES, NATIONAL MUNICIPAL STORMWATER
ALLIANCE, ASSOCIATION OF MISSOURI CLEANWATER
AGENCIES, MARYLAND MUNICIPAL STORMWATER
ASSOCIATION, NORTH CAROLINA WATER QUALITY
ASSOCIATION, SOUTH CAROLINA WATER QUALITY
ASSOCIATION, VIRGINIA MUNICIPAL STORMWATER
AGENCY, AND WEST VIRGINIA MUNICIPAL WATER
QUALITY ASSOCIATION’S BRIEF SUPPORTING
PETITIONER’S WRIT OF CERTIORARI FOR THE FIRST
QUESTION PRESENTED

__________________

AARON M. HERZIG
Counsel of Record
ERICA M. SPITZIG
TAFT STETTINIUS & HOLLISTER LLP
425 Walnut Street, Suite 1800
Cincinnati, Ohio 45202
(513) 357-8768
aherzig@taftlaw.com
Counsel for Amici Curiae
November 25, 2019

 i
TABLE OF CONTENTS
TABLE OF AUTHORITIES. . . . . . . . . . . . . . . . . . . iii
INTERESTS OF AMICI CURIAE . . . . . . . . . . . . . . . 1
SUMMARY OF ARGUMENT . . . . . . . . . . . . . . . . . . 4
ARGUMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
I. THE COURT OF APPEALS’ NOVEL AND
INCORRECT APPLICATION OF THE CLEAN
WATER ACT AND NPDES REGULATIONS
THREATENS TO EXPAND THE
OBLIGATIONS OF AMICI’S MEMBERS
SIGNIFICANTLY . . . . . . . . . . . . . . . . . . . . . . . . 10
A. The Maryland Court of Appeals’ Decision
Upends the Well-Settled Principle that
Permit Obligations Apply Only to Discharges
from Systems Owned or Operated by the
Permittee . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B. The Maryland Court of Appeals’ Decision Is
Inconsistent with How MS4s Are Designed
and Operate . . . . . . . . . . . . . . . . . . . . . . . . . . 13
II. THE DECISION COULD DIVERT CRITICAL
PUBLIC DOLLARS TO PAY FOR PRIVATE
POLLUTION AND SUBJECT AMICI’S
MEMBERS TO NEEDLESS LITIGATION,
ENFORCEMENT, AND CIVIL PENALTIES . . 18
A. The Court of Appeals’ Decision Will Cause
MS4s to Divert Critical Resources from
Existing Obligations . . . . . . . . . . . . . . . . . . . 18

 ii
B. The Court of Appeals’ Decision Could Subject
Amici’s Members to Additional Regulatory
Scrutiny, Government Enforcement Actions,
and Citizen Suits . . . . . . . . . . . . . . . . . . . . . . 20
CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

 iii
TABLE OF AUTHORITIES
CASES
Am. Littoral Soc’y v. EPA,
199 F. Supp. 2d 217 (D.N.J. 2002) . . . . . . . . . . . . 7
Anacostia Riverkeeper, Inc. v. Jackson,
798 F. Supp. 2d 210 (D.D.C. 2011). . . . 6, 7, 11, 12
Blue Water Baltimore, Inc. v. Wheeler,
No. GLR-17-1253, 2019 WL 1317087
(D. Md. Mar. 22, 2019) . . . . . . . . . . . . . . . . . . . . 13
Envtl. Def. Ctr., Inc. v. EPA,
344 F.3d 832 (9th Cir. 2003). . . . . . . . . . . . . . . . 13
Nat. Res. Def. Council, Inc. v. Cty. of Los Angeles,
725 F.3d 1194 (9th Cir. 2013). . . . . . . . . . . . 16, 17
Sierra Club v. Meiburg,
296 F.3d 1021 (11th Cir. 2002). . . . . . . . . . . . . . 11
United States v. Lake County, Utah, No. 2:16-cv0087 (D. Utah Feb. 2. 2016) . . . . . . . . . . . . . . . . 22
W. Virginia Highlands Conservancy, Inc. v.
Huffman, 588 F. Supp. 2d 678 (N.D.W. Va. 2009),
aff’d, 625 F.3d 159 (4th Cir. 2010) . . . . . . . . 10, 11
Zweig v. Metro. St. Louis Sewer Dist.,
412 S.W.3d 223 (Mo. 2013) . . . . . . . . . . . . . . . . . 19
STATUTES AND REGULATIONS
33 U.S.C. §§ 1251 et seq. (1972) . . . . . . . . . . . . passim
33 U.S.C. § 1313(d). . . . . . . . . . . . . . . . . . . . . . . . . . . 6

 iv
33 U.S.C. § 1319(d). . . . . . . . . . . . . . . . . . . . . . . . . . 23
33 U.S.C. § 1342(p)(3)(B)(iii) . . . . . . . . . . . . . . . . . . . 5
33 U.S.C. § 1362(14). . . . . . . . . . . . . . . . . . . . . . . . . . 4
33 U.S.C. § 1365 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
40 C.F.R. § 122.21(a)(1) . . . . . . . . . . . . . . . . . . . 10, 12
40 C.F.R. § 122.21(b) . . . . . . . . . . . . . . . . . . . . . 10, 12
40 C.F.R. § 122.26(a)(3)(ii) . . . . . . . . . . . . . . . . . . . . 15
40 C.F.R. § 122.26(a)(3)(iii) . . . . . . . . . . . . . . . . . . . 10
40 C.F.R. § 122.26(a)(8)(i) . . . . . . . . . . . . . . . . . . . . 15
40 C.F.R. § 122.26(a)(9)(i)(C) . . . . . . . . . . . . . . . . . . 13
40 C.F.R. § 122.26(a)(9)(i)(D) . . . . . . . . . . . . . . . . . . 13
40 C.F.R. § 122.26(b)(4) . . . . . . . . . . . . . . . . . . . . . . 14
40 C.F.R. § 122.26(b)(8) . . . . . . . . . . . . . . . . . . . . . . 10
40 C.F.R. § 122.32 . . . . . . . . . . . . . . . . . . . . . . . . . . 14
40 C.F.R. § 130.2(e) . . . . . . . . . . . . . . . . . . . . . . . . . . 6
40 C.F.R. § 130.2(i). . . . . . . . . . . . . . . . . . . . . . . . . . 12
OTHER AUTHORITIES
Black & Veatch Management Consulting, LLC,
2018 Stormwater Utility Survey (2018),
https://www.bv.com/sites/default/files/201910/18%20Stormwater%20Utility%20Survey%2
0Report%20WEB_0.pdf. . . . . . . . . . . . . . . . . 19, 20

 v
Brief of Intervenors-Appellees Virginia Association
of Municipal Wastewater Agencies, Maryland
Association of Municipal Wastewater Agencies,
and National Association of Clean Water
Agencies, American Farm Bureau Federation v.
EPA, 792 F.3d 281 (3d Cir. 2015) (No. 13-4079),
2014 WL 1652117 . . . . . . . . . . . . . . . . . . . . . . . . . 8
EPA, Basic Information about Nonpoint Source
Pollution, https://www.epa.gov/nps/basicinformation-about-nonpoint-source-nps-pollution
........................................ 4
EPA’s Combined Sewer Overflow reduction policy,
59 FR 18688 (April 19, 1994) . . . . . . . . . . . . . . . 21
EPA, Guidance for Water Quality Based Decisions:
The TMDL Process (1991). . . . . . . . . . . 7, 8, 12, 13
EPA, National Compliance Initiative: Keeping Raw
Sewage and Contaminated Stormwater Out of
Our
Nation’s
Waters
(Update),
https://www.epa.gov/enforcement/nationalcompliance-initiative-keeping-raw-sewage-andcontaminated-stormwater-out-our-0.. . . . . . 21, 22
National Association of Clean Water Agencies, Wet
Weather Consent Decrees: Negotiation Strategies
to Maximize Flexibility & Environmental
Benefit, A Handbook for Utilities (2016),
https://www.nacwa.org/news-publications/whitepapers-publications/wet-weather-consentdecrees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

 vi
National Pollutant Discharge Elimination System
Permit Application Regulations for Storm Water
Discharges, 55 FR 47990 (1990) . . . . . . . . . . . 5, 11
R. Raucher et al., Developing a New Framework for
Household Affordability and Financial
Capability Assessment in the Water Sector
(2019),
https://www.nacwa.org/docs/defaultsource/resources---public/developing-newframework-for-affordability-report(final).pdf?sfvrsn=dc1f361_2 . . . . . . . . . . . . 18, 19

 1
INTERESTS OF AMICI CURIAE
Amici are organizations from across the United
States whose members are public entities that provide
water conservation, flood and stormwater
management, and wastewater treatment services to
the public.1
The National Association of Clean Water Agencies
(“NACWA”) is a nonprofit trade association
representing the interests of publicly owned
wastewater and stormwater utilities across the United
States. NACWA’s members include over 300 municipal
clean water agencies that own, operate, and manage
publicly owned treatment works, water reclamation
districts, wastewater sewer systems, stormwater sewer
systems, water reclamation districts, and all aspects of
wastewater collection, treatment, and discharge. Clean
water utilities provide services that are essential to
protecting public health and the environment;
regulatory certainty is essential to allow utilities to
make and plan prudently for investments of public
funds.
The National Municipal Stormwater Alliance
(“NMSA”) was formed in 2017 and is a nonprofit
organization representing approximately 3,000

1

Pursuant to Rule 37.6 of the Rules of the Supreme Court, amici
state that no counsel for a party authored this brief in whole or in
part, and neither such counsel nor any party made a monetary
contribution intended to fund the preparation or submission of the
brief. Counsel of record received notice at least 10 days prior to the
due date of the amici’s intention to file this brief. All counsel of
record have consented to the filing of this brief.

 2
municipal separate storm sewer system (“MS4”)
permittees located within 15 states across eight EPA
regions. NMSA’s vision is to support MS4 permittees
across the country, enabling them to develop efficient
and effective stormwater programs. NMSA serves as a
voice for MS4 communities, advocating for sciencebased policies and better understanding of local
stormwater management programs.
The Maryland Municipal Stormwater Association
(“MAMSA”) is a statewide association of 20 counties,
cities, and towns that own and operate municipal
separate storm sewer systems regulated under the
Clean Water Act.
The Association of Missouri Cleanwater Agencies
(“AMCA”) is a statewide association of 21 local
governmental entities that own and operate facilities
regulated under the Clean Water Act, including
municipal separate storm sewer systems.
The North Carolina Water Quality Association
(“NCWQA”) is a statewide association of 41 local
governmental entities that own and operate facilities
regulated under the Clean Water Act, including
municipal separate storm sewer systems.
The South Carolina Water Quality Association
(“SCWQA”) is a statewide association of 39 local
governmental entities that own and operate facilities
regulated under the Clean Water Act, including
municipal separate storm sewer systems.
The Virginia Association of Municipal Stormwater
Agencies (“VAMSA”) is a statewide association of 43
counties, cities, and other public entities that own and

 3
operate municipal separate storm sewer systems
regulated under the Clean Water Act.
The West Virginia Municipal Water Quality
Association (“WVMWQA”) is a statewide association of
31 local governmental entities that own and operate
facilities regulated under the Clean Water Act,
including municipal separate storm sewer systems.
Amici submit this brief based on their members’
compelling interest in ensuring that the Clean Water
Act National Pollutant Discharge Elimination System
(“NPDES”) permitting scheme, 33 U.S.C. §§ 1251 et seq.
(1972), and attendant Clean Water Act liability,
remains predictable and lawfully within the scope of
the Clean Water Act. Amici’s members are public
agencies funded by local rate and taxpayers, and whose
limited dollars are dedicated to protecting water
quality in the communities they serve. Amici’s
members are stewards of public health, the
environment, and public funds, whose work requires
substantial investment in major infrastructure projects
designed to have the greatest environmental impact
within limited ratepayer dollars. Requiring amici’s
members to address discharges that are not within
their boundaries, do not discharge to their systems, and
over which they have no control, threatens their ability
to complete necessary projects and meet existing
regulatory obligations.

 4
SUMMARY OF ARGUMENT
A narrow majority of the Maryland Court of Appeals
decided that NPDES permits for municipal separate
storm sewer systems (“MS4s”) can require MS4s to
remediate nonpoint source pollution that does not
originate from—or even enter—their systems, is
outside the service area of their systems, and over
which they have no authority or control.2 The four-tothree majority reached its decision over two dissenting
opinions by misinterpreting the Clean Water Act and
its enabling regulations. The decision is likely to
significantly expand the obligations of local
communities that own and operate MS4s—and all
point source owners and operators—far beyond what
the Clean Water Act and NPDES permit program
allow.
Like all point sources, MS4s are required to obtain
NPDES permits that set limits on the pollutants

2

The NPDES program expressly regulates discharges from “point
sources,” which are “any discernible, confined and discrete
conveyance, including but not limited to any pipe, ditch, channel,
tunnel, conduit, well, discrete fissure, container, rolling 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). Nonpoint
source pollution is not defined in the Clean Water Act, but
generally includes sheet flow runoff from impervious surfaces in
urban areas, runoff from agricultural lands, and seepage through
groundwater. See EPA, Basic Information about Nonpoint Source
Pollution,
https://www.epa.gov/nps/basic-information-about-nonpoint-sourcenps-pollution.

 5
discharged from their pipes. MS4s differ from nonstormwater point sources in that their flows are not
conveyed to a treatment plant and discharged from a
single pipe at the end of the process. Instead, MS4s
convey stormwater generated from precipitation events
through diffuse networks of pipes and other
conveyances that may or may not be interconnected
and may serve only a portion of a community or
jurisdiction. Stormwater picks up pollutants from a
variety of sources, which are then discharged through
MS4s directly into surface water. Because MS4s cannot
control the amount or frequency of pollutants that
enter their systems, MS4s are required to implement
best management practices (“BMPs”) or other controls
designed to prevent pollutants from flowing into their
systems, with the goal of reducing the amount of
pollutants discharged from their systems to the
maximum extent practicable (“MEP”). 33 U.S.C.
§ 1342(p)(3)(B)(iii).3
In this case, Petitioner County Commissioners of
Carroll County, Maryland (“Carroll County”) filed for
a renewal of the NDPES permit for its MS4, and
Maryland Department of the Environment (“MDE”)
issued a permit that not only includes these BMPs, but
also requires Carroll County to reduce impervious
surfaces by 20% county-wide. Like many MS4s, Carroll
3

National Pollutant Discharge Elimination System Permit
Application Regulations for Storm Water Discharges, 55 FR 4799001 (1990) (“Storm water discharges are intermittent by their
nature, and pollutant concentrations in storm water discharges
will be highly variable. Not only will variability arise between
given events, but the flow and pollutant concentrations of such
discharges will vary with time during an event.”).

 6
County’s MS4 serves only certain portions of the county
rather than the entire jurisdiction, and Carroll County
therefore appealed the permit, arguing, among other
things, that requiring county-wide impervious surface
reductions exceeded MDE’s authority and was
arbitrary and capricious.
The Court of Appeals approved MDE’s new
permitting requirements by misinterpreting a core
element of the Clean Water Act “total maximum daily
load” (“TMDL”) process: the assignment of additional
load reduction requirements to point sources where
nonpoint source reductions cannot be guaranteed. See
33 U.S.C. § 1313(d). States develop TMDLs where
controls on point sources alone are insufficient to allow
a water body to attain water quality standards. For
each waterbody in “nonattainment,” a state develops
TMDLs, commonly thought of as pollution budgets,
identifying the existing point source and nonpoint
source discharges and allotting pollution loads that can
be discharged from each source that will allow the
waterbody to achieve “attainment” status. Id.
Point sources are assigned “wasteload allocations,”
while nonpoint sources receive “load allocations,” but in
either case, the relevant “load” means the amount of a
pollutant that is either attributable to or can be
discharged from that source.4 Anacostia Riverkeeper,
Inc. v. Jackson, 798 F. Supp. 2d 210, 216 (D.D.C. 2011)
4

Load or loading is “[a]n amount of matter or thermal energy that
is introduced into a receiving water; to introduce matter or
thermal energy into a receiving water. Loading may be either mancaused (pollutant loading) or natural (natural background
loading).” 40 C.F.R. § 130.2(e).

 7
(“In addition to setting a maximum daily level of
pollution, EPA regulations require TMDLs to allocate
contaminant loads among point and non-point sources
of pollution.”). When all sources are limiting their
discharges to their wasteload and load allocations only,
the waterbody should attain water quality standards.
Once the relevant allocations are made, the loads
are translated into permit limits for point sources and
nonpoint source BMPs to ensure compliance. EPA,
Guidance for Water Quality Based Decisions: The
TMDL Process, 23-25 (1991) (“TMDL Guidance”). If
pollutant reductions cannot be achieved, however, more
stringent pollutant limits may be imposed on point
sources. Anacostia Riverkeeper, 798 F. Supp. 2d at 21617 (“This process also ensures that the flows of
contaminants from point sources are adjusted to
account for non-point source pollution, which is
inherently more difficult to monitor, control, or
reduce.”) (citing Am. Littoral Soc’y v. EPA, 199 F. Supp.
2d 217, 229 (D.N.J. 2002)).
The Maryland Court of Appeals’ decision here
inserted into this process a mandatory obligation for
point sources to reduce the discharge of pollutants from
nonpoint sources—i.e., pollution that is generated
outside an MS4’s service area, does not flow into the
MS4’s pipes, and over which the MS4 has no authority
or control. Petitioner’s Appendix (“Pet. App.”) 71a-74a.5
5

Amici object to Maryland’s imposition of the new burden for
nonpoint source reductions on a nearby MS4. Nonpoint source
reductions have no place in an NPDES permit, absent the
permittees’ consent to achieve these reductions and corresponding
credit from the permitting agency in the form of less stringent

 8
This holding directly contradicts the longstanding
approach whereby a point source would be required to
further reduce its own loading if the original
allocations were insufficient, or nonpoint source
reductions could not be guaranteed to achieve
attainment of water quality standards. This expanded
reading of MS4 permittees’ obligations would
undermine the ability of amici’s members to comply
with their NPDES permits, divert critical public
resources to address private pollution, and subject
them to needless litigation and enforcement actions
from regulators and citizen groups. Additionally, this
expansion puts amici’s members in a perilous position
because they lack legal control over activities on these
nonpoint source properties, and thus have no legal
mechanism to require and enforce the loading
reductions, which will result in permit violations
through no fault of their own.
Amici request that the Court grant the Petition for
Writ of Certiorari of Carroll County. Amici are
particularly interested in Question Presented No. 1 for
the following reasons:

permit obligations. See TMDL Guidance at 24-25. Amici do not
dispute the importance of plans to implement TMDLs in a manner
that reduces pollutants discharged from nonpoint sources. Control
of nonpoint sources is crucial to the Clean Water Act’s purpose,
and NACWA advocated for the inclusion of nonpoint source
allocations in the Chesapeake Bay TMDL. See Brief of IntervenorsAppellees Virginia Association of Municipal Wastewater Agencies,
Maryland Association of Municipal Wastewater Agencies, and
National Association of Clean Water Agencies at 11-22, American
Farm Bureau Federation v. EPA, 792 F.3d 281 (3d Cir. 2015) (No.
13-4079), 2014 WL 1652117.

 9
1. The Court of Appeals’ decision is a novel and
incorrect interpretation of the Clean Water Act
that upends allocation of pollutants among
relevant sources through the TMDL process.
2. The decision could require amici’s members to
dramatically increase rates/taxes on the people
they serve in order to clean up messes for people
and businesses that they do not serve and who
do not pay the corresponding rates/taxes. The
decision would also impose obligations on amici’s
members that they cannot meet. Their inability
to comply with these obligations will subject
them to additional regulatory scrutiny,
enforcement actions and citizen suits, and
potentially substantial civil penalties.
3. While amici’s members care a great deal about
Clean Water Act compliance, the law does not
force them to take on burdens that are outside of
their control. And doing so would divert already
limited ratepayer dollars from critical
infrastructure projects and existing permit
obligations.
As agencies tasked with and devoted to protection of
the environment and water quality, amici’s members
often advocate for more stringent regulation of
nonpoint sources. But the Maryland Court of Appeals’
decision undoes the existing regulatory structure and
would burden amici’s members with addressing
discharges for which they lack authority or funding.
Amici therefore request that the Court grant Carroll
County’s Petition for Writ of Certiorari.

 10
ARGUMENT
I. THE COURT OF APPEALS’ NOVEL AND
INCORRECT APPLICATION OF THE CLEAN
WATER ACT AND NPDES REGULATIONS
THREATENS
TO
EXPAND
THE
OBLIGATIONS OF AMICI’S MEMBERS
SIGNIFICANTLY
A. The Maryland Court of Appeals’ Decision
Upends the Well-Settled Principle that
Permit Obligations Apply Only to
Discharges from Systems Owned or
Operated by the Permittee.
The Maryland Court of Appeals’ four-to-three
decision upends a well-established principle of NPDES
permitting: that permittees are responsible only for
discharges from conveyances that they own or operate.
See 40 C.F.R. § 122.21(a)(1), (b) (“Any person who
discharges or proposes to discharge pollutants” must
obtain a permit, and where owner and operator are
different persons, operator must obtain the permit); 40
C.F.R. § 122.26(a)(3)(iii) (requiring “operator of a
discharge” from an MS4 to obtain a permit). The
definition of a “municipal separate storm sewer” rests
on the idea that the stormwater conveyances are
“owned or operated” by a public agency. 40 C.F.R.
§ 122.26(b)(8). See also W. Virginia Highlands
Conservancy, Inc. v. Huffman, 588 F. Supp. 2d 678,
691–92 (N.D.W. Va. 2009), aff’d, 625 F.3d 159 (4th Cir.
2010) (state agency, as “operator” of discharges,
required to obtain NPDES permit).

 11
The NPDES program does not contemplate that
dischargers will be responsible for discharges they do
not own or operate. Instead, “[t]he NPDES is a permit
program through which individual entities responsible
for covered point sources receive permits setting the
maximum discharges of particular contaminants via
these sources.” Anacostia Riverkeeper, 798 F. Supp. 2d
at 214. See also Sierra Club v. Meiburg, 296 F.3d 1021,
1024 (11th Cir. 2002) (“The statute gives EPA the
authority to issue permits for point sources.”).
Before this decision, EPA and MS4 operators had a
common understanding that NPDES permits are
designed to address only those discharges that emanate
from their systems. National Pollutant Discharge
Elimination System Permit Application Regulations for
Storm Water Discharges, 55 FR 47990-01 (1990)
(“Under today’s rule, appropriate municipal owners or
operators of these systems must obtain NPDES
permits for discharges from these systems.” (emphasis
added)). And EPA specifically explained that the MS4
“rulemaking only covers storm water discharges from
point sources,” that MS4s fall within the statutory
definition of point sources (i.e., any discernable,
confined, and discrete conveyance), and that “a storm
water discharge subject to NPDES regulation does not
include storm water that enters the waters of the
United States via means other than a ‘point source.’”
Id.
The Court of Appeals did not suggest that Carroll
County somehow owned or operated the nonpoint
sources at issue or that the discharges flowed through
Carroll County’s MS4. Instead, it determined that

 12
because point sources bear the burden of pollutant
reductions where nonpoint source reductions cannot be
achieved, point sources must effectively be responsible
for nonpoint source discharges. Pet. App. 41a-45a. This
interpretation directly contradicts the NPDES
regulations stating that “persons” are required to
obtain permits for only those discharges they own or
operate. E.g., 40 C.F.R. § 122.21(a)(1), (b).
The Maryland Court of Appeals’ view of the TMDL
process is also not supported by relevant authority. The
definition of TMDL establishes that the nonpoint
source tradeoffs contemplated by the regulation involve
controls on the point source itself:
If Best Management Practices (BMPs) or other
nonpoint source pollution controls make more
stringent load allocations practicable, then
wasteload allocations can be made less
stringent. Thus, the TMDL process provides for
nonpoint source control tradeoffs.
40 C.F.R. § 130.2(i). See also Anacostia Riverkeeper,
798 F. Supp. 2d at 216-17 (“This process also ensures
that the flows of contaminants from point sources are
adjusted to account for non-point [sic] source pollution,
which is inherently more difficult to monitor, control,
or reduce.” (emphasis added)).
And the Court of Appeals overlooked existing
regulatory tools to address both nonpoint discharges
and private storm sewers that do not discharge into an
MS4. The TMDL Guidance outlines specific suggested
BMPs for nonpoint sources that can be adopted by
states. TMDL Guidance at 23-24. EPA also retains

 13
“residual designation authority” to require an NPDES
permit for any discharges from private storm sewers
owned by commercial, industrial, and institutional
entities (“CII sources”) that threaten water quality.
Envtl. Def. Ctr., Inc. v. EPA, 344 F.3d 832, 874 (9th Cir.
2003) (upholding EPA’s residual authority to require
CII sources to obtain NPDES permits where “the
discharge, or category of discharges within a
geographic area, contributes to a violation of a water
quality standard or is a significant contributor of
pollutants to waters of the United States”) (quoting 40
C.F.R. §§ 122.26(a)(9)(i)(C)-(D)). See also Blue Water
Baltimore, Inc. v. Wheeler, No. GLR-17-1253, 2019 WL
1317087, *4-5 (D. Md. Mar. 22, 2019).
If the Court of Appeals is correct, point sources
could now be required not only to reduce the amount of
pollutants in their own discharges, but also to reduce
the amount of pollutants discharged from nonpoint
sources that do not flow into their systems and over
which they have no authority or control. This view has
no basis in the Clean Water Act, as described above.
B. The Maryland Court of Appeals’ Decision Is
Inconsistent with How MS4s Are Designed
and Operate.
The Court of Appeals also misinterpreted the Clean
Water Act’s inclusion of a “jurisdiction-wide”
permitting option for MS4s in holding that Carroll
County’s permit could require impervious surface
reductions county-wide, without regard to the MS4
service area. Pet. App. 62a-64a. The Court of Appeals’
interpretation is contradicted by the unique nature of

 14
MS4s and the body of law that has developed regarding
the MS4 permitting scheme as a result.
The boundaries of an MS4 are established in two
ways: first, by the limits of the urbanized areas or
incorporated places within the jurisdiction; and then,
further, by the limits of the actual MS4 system (i.e., the
network of pipes and other conveyances). For example,
Carroll County owns and operates an MS4 that serves
only certain portions of the County, primarily in the
more densely populated areas. Petition at 4.
The NPDES regulations draw MS4 boundaries
based on areas of incorporation and Census-defined
urbanized areas, rather than entire jurisdictions. Large
and medium MS4s are defined to included only those
MS4s located in incorporated places meeting specific
population thresholds under 40 C.F.R. § 122.26(b)(4),
while small MS4s require NPDES permits only for the
portions of the system located within a Censusdesignated urbanized area, unless the permitting
authority determines that the MS4 is a cause of water
quality impairment. See 40 C.F.R. § 122.32 (“If your
small MS4 is not located entirely within an urbanized
area, only the portion that is within the urbanized area
is regulated.”). The dissent correctly explained that
MDE lacked authority to require restoration of
impervious surfaces county-wide, but instead “each
county should be responsible only for restoring 20% of
impervious surfaces in urbanized areas; in other words,
the areas that each county’s MS4 serves should be the
same as the area in which the county’s MS4 permit
makes the county responsible for restoring 20% of

 15
impervious surfaces.” Pet. App. 131a (Watts, Hotten,
and Getty, JJ., dissenting).
And even within these incorporated and urbanized
areas, an MS4 does not necessarily extend to the
boundaries of the urbanized area. Instead, an MS4 is
defined to include only the system of pipes and other
infrastructure that convey stormwater to waters of the
United States:
Municipal separate storm sewer means a
conveyance or system of conveyances (including
roads with drainage systems, municipal streets,
catch basins, curbs, gutters, ditches, man-made
channels, or storm drains):
Owned or operated by a State, city, town,
borough, county, parish, district, association, or
other public body … that discharges to waters of
the United States …
40 C.F.R. § 122.26(a)(8)(i). So, where a community
owns and operates only a small number of stormwater
conveyances that serve a very small area within a
larger community, the permit applies only to that
system of conveyances and to the portion of the
urbanized area actually served.
The “jurisdiction-wide” nature of some MS4 permits
therefore does not mean that the MS4 owner or
operator is responsible for all stormwater within the
jurisdiction, but instead applies to all portions of the
MS4 that fall within the relevant jurisdiction. This is
consistent with 40 C.F.R. § 122.26(a)(3)(ii), which
contemplates issuance of permits to entire systems
(system-wide) or portions of systems located within a

 16
specific jurisdiction (jurisdiction-wide), which may
make up only a portion of the larger whole:
The Director may either issue one system-wide
permit covering all discharges from municipal
separate storm sewers within a large or medium
municipal storm sewer system or issue distinct
permits for appropriate categories of discharges
within a large or medium municipal separate
storm sewer system including, but not limited
to: all discharges owned or operated by the same
municipality; located within the same
jurisdiction; all discharges within a system that
discharge to the same watershed; discharges
within a system that are similar in nature; or for
individual discharges from municipal separate
storm sewers within the system.
This section makes clear that jurisdiction-wide permits
are intended to address situations where portions of an
interconnected MS4 fall within different jurisdictions
and allows for permitting of smaller pieces of the larger
whole. This means that, for example, Carroll County
could have been issued multiple NPDES permits for
portions of its system that fall within specific towns or
cities (jurisdiction-wide) rather than the single permit
it obtained covering its entire system (system-wide).
This approach to MS4 permitting is grounded in the
very nature of MS4s, which are diffuse networks of
pipes and other conveyances that may not be
interconnected or even geographically adjacent, and
which may have hundreds of outfalls at various points
throughout the system. In Nat. Res. Def. Council, Inc.
v. Cty. of Los Angeles, 725 F.3d 1194, 1208-09 (9th Cir.

 17
2013), the Ninth Circuit explained that MS4s “often
cover many square miles and comprise numerous,
geographically scattered, and sometimes uncharted
sources of pollution, including streets, catch basins,
gutters, man-made channels, and storm drains,” and
that therefore “Congress recognized that for large
urban areas… ms4 [sic] permitting cannot be
accomplished on a source-by-source basis” and
therefore provided permitting authorities discretion to
issue permits “on a system-wide or jurisdiction-wide
basis,” rather than requiring “separate permits for
millions of individual stormwater discharge points.”
Because of the unique nature of MS4s, “[t]his increased
flexibility is crucial in easing the burden of issuing
stormwater permits for both permitting authorities and
permittees.” Id. See also Anacostia Riverkeeper, 798
F.Supp. 2d at 248-49 (holding that individual
wasteload allocations not required for each MS4 outfall
due to the unique nature of MS4s).
The Court of Appeals’ new requirement that MS4s
address nonpoint sources could greatly expand the
obligations of all NPDES permittees in a way that is
inconsistent with the Clean Water Act, imposes new
funding burdens on ratepayers, and is impossible for
point sources to achieve.

 18
II. THE DECISION COULD DIVERT CRITICAL
PUBLIC DOLLARS TO PAY FOR PRIVATE
POLLUTION AND SUBJECT AMICI’S
MEMBERS TO NEEDLESS LITIGATION,
ENFORCEMENT, AND CIVIL PENALTIES
The effect of this expansion likely will be to require
amici’s members to divert their limited public
ratepayer dollars to address private sources of
pollution, stormwater that does not enter amici’s
members’ systems, but rather runs off of private
commercial and residential property, and may even
flow through privately owned storm sewers. The Court
of Appeals’ decision would require amici’s public
agency members and the millions of ratepayers who
fund them to bear the burden of addressing these
private sources. And complying with these
requirements will prove impossible, subjecting amici’s
members to additional regulatory scrutiny and
enforcement by regulators and citizen groups.
A. The Court of Appeals’ Decision Will Cause
MS4s to Divert Critical Resources from
Existing Obligations.
The Court of Appeals’ decision will divert already
limited funding from critical infrastructure projects
and the necessary functions of MS4 compliance to
address these private sources. As it stands, amici’s
members and their ratepayers face a funding shortfall
for their existing obligations. Rates for municipal
water, wastewater, and stormwater services have
increased substantially since the mid-1980s at a rate
that outpaces both inflation and the costs of other
essential household services. R. Raucher et al.,

 19
Developing a New Framework for Household
Affordability and Financial Capability Assessment in
the Water Sector, 1-3-1-4 (2019).6 And yet, these rising
rates fall far short of the funding required by many
communities to meet regulatory requirements, update
aging infrastructure, and respond to climate change.
Id. at 1-4.7
MS4s in particular face an uphill battle to obtain
the necessary funding and ratepayer buy-in necessary
to implement their programs. A 2018 survey of
stormwater utilities across the United States found
that over a quarter of respondents had faced legal
challenges to their stormwater fees. Black & Veatch
Management Consulting, LLC, 2018 Stormwater
Utility Survey, 40 (2018).8 Many of these challenges are
based on the nexus between the service provided and
the actual use of the system by individual properties.
E.g., Zweig v. Metro. St. Louis Sewer Dist., 412 S.W.3d
223 (Mo. 2013). Requiring MS4s to address discharges
from private sources not connected to their systems
will only subject amici’s members to further litigation
from ratepayers challenging the proper scope of their
services and the corresponding fees they charge.
6

https://www.nacwa.org/docs/default-source/resources--public/developing-new-framework-for-affordability-report(final).pdf?sfvrsn=dc1f361_2.
7

Estimates place the needed investment to replace aging water
infrastructure and respond to climate change anywhere from more
than $36 billion by 2050 to $1 trillion over the next 25 years. Id.

8

https://www.bv.com/sites/default/files/201910/18%20Stormwater%20Utility%20Survey%20Report%20WEB
_0.pdf.

 20
And even where courts reject challenges to
stormwater fees, these utilities face significant funding
shortfalls to meet their existing obligations. The 2018
survey of stormwater utilities, referenced above, found
that less than half of respondents reported that their
funding was sufficient to meet their obligations, with
nine percent indicating they lacked funding to address
urgent needs. Black & Veatch at 24. The Maryland
Court of Appeals’ decision will further stretch these
already limited dollars to pay for pollution not even
passing through amici’s members’ systems. To remedy
this situation and consider the full range of impacts
associated with requiring point sources to address
discharges from nonpoint sources, amici request that
the Court grant Carroll County’s Petition for
Certiorari.
B. The Court of Appeals’ Decision Could
Subject Amici’s Members to Additional
Regulatory Scrutiny, Government
Enforcement Actions, and Citizen Suits.
The Maryland Court of Appeals’ decision expands
the regulatory burden on an already overburdened
water sector and the ratepayers they serve, and
compliance with this expanded burden will often be
impossible. Amici’s members are in the business and
dedicated to the mission of protecting the environment
and water quality in the communities they serve. And
Amici frequently advocate for more stringent
regulation of nonpoint sources of water pollution
because of the substantial contribution they make to
impairment of the nation’s waterbodies. But amici’s
members have no resources, ability, or authority to

 21
restrict discharges from sources that do not flow
through their systems. And the Maryland Court of
Appeals’ decision will place them at risk of
noncompliance and enforcement actions.
The Court of Appeals’ decision would require MS4s
to address discharges over which they have no control.
Amici’s members are public agencies whose authority
is defined by state statutes, and who may lack
authority to implement the type of impervious surface
area reductions contemplated in the County’s permit,
which would require the passage of ordinances
governing impervious surfaces in areas that do not
discharge to their systems. And even if they could,
compliance would require authority, staffing, and
resources to ensure that runoff from thousands of
individual properties is addressed in perpetuity, a
scenario in which failure is certain. As such, the Court
of Appeals’ decision places amici’s members at risk of
enforcement actions brought by regulators and citizen
groups, and imposition of civil penalties and attorneys’
fees.
Amici’s members have faced intense regulatory
scrutiny over the last quarter century, since the
adoption of EPA’s Combined Sewer Overflow (“CSO”)
reduction policy in 1994. 59 FR 18688 (April 19, 1994).
EPA began prioritizing “Keeping Raw Sewage and
Contaminated Stormwater out of Our Nation’s
Waterways” as one of its top enforcement initiatives in
the year 2000, and only recently announced the return
of this initiative to its core programs in early 2019.
EPA, National Compliance Initiative: Keeping Raw
Sewage and Contaminated Stormwater Out of Our

 22
Nation’s Waters (Update).9 In that time, EPA took
enforcement or compliance assurance action at 97
percent of large combined sewer systems, 92 percent of
large sanitary sewer systems, and 79 percent of large
and medium MS4s. Id. The return of this initiative to
EPA’s core programs does not represent the conclusion
of enforcement against amici’s members, as many
utilities nationwide have entered into multi-million, or
even billion, dollar consent decrees that will take
decades to implement. And because of the lengthy
negotiations required to develop these decrees, many
more remain in the process. See National Association
of Clean Water Agencies, Wet Weather Consent Decrees:
Negotiation Strategies to Maximize Flexibility &
Environmental Benefit, A Handbook for Utilities, 8
(2016).10
Requiring MS4s to address pollution over which
they have no control will bring additional enforcement
focus on amici’s members. Where an MS4 lacks
authority to require the type of impervious surface
reductions required by Carroll County’s permit, it will
face continued regulatory scrutiny and enforcement for
its inability to comply with permit obligations. And
where regulators decline to bring enforcement actions,

9

https://www.epa.gov/enforcement/national-compliance-initiativekeeping-raw-sewage-and-contaminated-stormwater-out-our-0.
10

https://www.nacwa.org/news-publications/white-paperspublications/wet-weather-consent-decrees. In at least one case,
EPA required a Utah county to enter into this type of multi-year,
federal consent decree focused solely on the county’s MS4 permit
obligations. United States v. Lake County, Utah, No. 2:16-cv-0087
(D. Utah Feb. 2. 2016).

 23
the Clean Water Act allows citizens to bring suit and
collect attorneys’ fees for their efforts. 33 U.S.C. § 1365.
In either scenario, the Clean Water Act imposes
substantial civil penalties for NPDES permit violations
for each day that the violation persists.11
The Court of Appeals’ decision would impose an
impossible task on amici’s members, who are dedicated
to protecting water quality in the communities they
serve, but have no ability to address discharges over
which they have no control. And requiring them to do
so will subject them to unnecessary enforcement.
Therefore, Amici request that this Court grant Carroll
County’s Petition for Writ of Certiorari.

11

The current maximum civil penalty for NPDES permit violations
is $54,833 for each day of each violation. 33 U.S.C. § 1319(d).

 24
CONCLUSION
For the foregoing reasons, amici request that
Carroll County’s Petition for Writ of Certiorari be
granted, particularly Question Presented No. 1. The
Maryland Court of Appeals’ decision threatens to
expand amici’s members’ obligations significantly to
require them to address discharges over which they
have no authority, ownership, or control. This will
require diversion of necessary public ratepayer dollars
to pay for private pollution, while subjecting amici’s
members to enforcement actions and citizen suits.
Respectfully submitted,
AARON M. HERZIG
Counsel of Record
ERICA M. SPITZIG
TAFT STETTINIUS & HOLLISTER LLP
425 Walnut Street, Suite 1800
Cincinnati, Ohio 45202
(513) 357-8768
aherzig@taftlaw.com
Counsel for Amici Curiae
NOVEMBER 25, 2019