MARYLAND DEPARTMENT OF THE ENVIRONMENT, et al.
ANACOSTIA RIVERKEEPER, et al.; BLUE WATER BALTIMORE, et al.
MARYLAND DEPARTMENT OF THE ENVIRONMENT; BLUE WATER BALTIMORE, et al.
MARYLAND DEPARTMENT OF THE ENVIRONMENT, et al
November 5, 2015.
Corrected May 3, 2016.
Circuit Court for Montgomery County. Case No.: 339466.
Certiorari to the Court of Special Appeals (Circuit Court for
Montgomery County). Ronald B. Rubin JUDGE.
Court for Anne Arundel County. Case No.: 02-C-14-186144.
Appeals from the Circuit Courts for Baltimore County, Anne
Arundel County and Prince George's County. H. Patrick
Stringer, Jr., Laura S. Kiessling, Beverly J. Woodard JUDGES.
Court for Baltimore City. Case No.: 24-C-14-000364. Appeal
from the Circuit Court for Baltimore City. Kendra Y. Ausby
CASE NO. 42, JUDGMENT OF THE COURT OF SPECIAL APPEALS
REVERSED. CASE REMANDED TO THAT COURT WITH DIRECTIONS TO
REVERSE THE JUDGMENT OF THE CIRCUIT COURT FOR MONTGOMERY
COUNTY AND AFFIRM MDE'S DECISION TO ISSUE THE MONTGOMERY
COUNTY PERMIT. COSTS TO BE PAID BY RESPONDENT. IN CASE NOS.
43 & 44, JUDGMENTS OF THE CIRCUIT COURTS FOR ANNE ARUNDEL
COUNTY, BALTIMORE CITY, BALTIMORE COUNTY, AND PRINCE
GEORGE'S COUNTY AFFIRMED. COSTS TO BE PAID BY PETITIONER.
BY Paul N. De Santis, Assistant Attorney General (Brian E.
Frosh, Attorney General of Maryland of Baltimore, MD) on
brief FOR PETITIONERS
BY Jennifer C. Chavez (Khushi K. Desai, Earthjustice of
Washington, DC) on brief FOR RESPONDENTS
BY Jennifer C. Chavez (Khushi K. Desai, Earthjustice,
Washington, DC) on brief FOR APPELLANTS
BY Paul W. Smail (Jon Mueller, Chesapeake Bay Foundation,
Inc. of Annapolis, MD) on brief FOR APPELLANTS
BY Paul N. De Santis, Assistant Attorney General (Brian E.
Frosh, Attorney General of Maryland of Baltimore, MD; Nancy
McCutchan Duden, County Attorney, Kelly Phillips Kenney,
Assistant County Attorney, Anne Arundel County Office of Law
of Annapolis, MD; M. Andree Green, County Attorney, Josue
Pierre, Associate County Attorney, Prince George's County
Office of Law of Upper Marlboro, MD) on brief FOR APPELLEE
BY Jennifer C. Chavez (Khushi K. Desai, Earthjustice,
Washington, DC Paul W. Smail, Jon Mueller, Chesapeake Bay
Foundation, Inc. of Annapolis, MD) on brief FOR APPELLANTS
BY M. Rosewin Sweeney (Thomas M. Lingan, Diana M. Krevor,
Venable, LLP of Baltimore MD; George A. Nilson, City
Solicitor, Baltimore City Law Department of Baltimore, MD) on
brief FOR APPELLEES
BY Paul N. De Santis, Assistant Attorney General (Brian E.
Frosh, Attorney General of Maryland of Baltimore, MD; Nancy
McCutchan Duden, County Attorney, Kelly Phillips Kenney,
Assistant County Attorney, Anne Arundel County Office of Law
of Annapolis, MD; M. Andree Green, County Attorney, Josue
Pierre, Associate County Attorney, Prinre George's County
Office of Law of Upper Marlboro, MD) on brief FOR APPELLEES
BEFORE: Barbera, C.J., Battaglia, Greene, Adkins, McDonald,
Watts, Harrell, Glenn T., Jr. (Retired, Specially Assigned),
Md. 95] Adkins, J.
AND LEGAL PROCEEDINGS
Department of the Environment (" MDE" ) issued
municipal separate storm sewer system (" MS4" )
discharge permits (" the Permits" ) to Anne Arundel
County, Baltimore City, Baltimore County, Montgomery County,
and Prince George's County (" the Counties" ).
Multiple organizations argue that the Permits do not comply
with federal and state law, and they request that we remand
for MDE to correct these legal errors.
Md. 96]Federal Framework: NPDES Permits and Municipal
the Clean Water Act (" CWA" ), the discharge of
pollutants is illegal. 33 U.S.C. § 1311. Through the
National Pollution Discharge Elimination System ("
NPDES" ), 33 U.S.C. § 1342, either the
Environmental Protection Agency (" EPA" ) or an
EPA-approved state, such as Maryland, may issue permits
exempting a discharger from this prohibition. See
Piney Run Pres. Ass'n v. Cnty. Comm'rs of Carroll
Cnty., Md., 268 F.3d 255, 265 (4th Cir. 2001). MDE is
the authority in Maryland that administers the NPDES program.
Code of Maryland Regulations (" COMAR" )
26.08.04.07. An NPDES permit, however, does not give a
discharger carte blanche. " Generally speaking, the
NPDES requires dischargers to obtain permits that place
limits on the type and quantity of pollutants that can be
released into the Nation's waters." S. Fla.
Water Mgmt. Dist. v. Miccosukee Tribe, 541 U.S. 95, 102,
124 S.Ct. 1537, 158 L.Ed.2d 264 (2004). These limits are
called effluent limitations. See 33 U.S.C. §
1362(11) (defining an effluent limitation as " any
restriction established by a State or the Administrator on
quantities, rates, and concentrations of chemical, physical,
biological, and other constituents which are discharged from
point sources into navigable waters, the waters of the
contiguous zone, or the ocean, including schedules of
compliance" ). The type of discharge determines the type
of limitations the permit must impose on the discharger.
Permits before us control stormwater pollutant
discharge. [447 Md. 97] Stormwater consists of
the rain and snowmelt that filters through the soil and
courses over surfaces--collecting pollutants along the
way--before passing through the municipal storm sewer
systems and into waterbodies. During the
development of the Permits, the Water Groups explained the
problems that stormwater poses, whether to the surface
conditions of Maryland's waters, for humans who recreate
and subsist on them, and for wildlife who live in them.
See Letter with Comments on Draft MS4 Permit for
Baltimore City from Blue Water Baltimore, Inc. and
Earthjustice, to Brian Clevenger, MDE (Sept. 21, 2012). In
recognition of extensive public commentary on the severity of
the problems associated with stormwater, MDE stated: "
[i]t becomes fairly easy for all organizations, individuals,
and government agencies to agree that urban stormwater is a
problem that must be addressed." MDE, Response to Formal
Comments for Montgomery County NPDES Permit (2009).
municipal stormwater discharge is " highly
intermittent," " usually characterized by very high
flows occurring over relatively short time intervals,"
and " depend[s] on the activities occurring on the
lands." See National Pollutant [447 Md. 98]
Discharge Elimination System Permit Application Regulations
for Storm Water Discharges, 55 Fed.Reg. 47,990, 48,038 (Nov.
16, 1990) (codified at 40 C.F.R. § 122.26). It is also
difficult to discern the amount of pollutant that any one
discharger contributes to a waterbody because municipalities
have so many outfalls, or discharge points, leading into the
waters. See MDE, Montgomery County NPDES Permit Fact
Sheet (900 outfalls); MDE, Anne Arundel County NPDES Permit
Fact Sheet (nearly 1,000 outfalls); MDE, Baltimore County
NPDES Permit Fact Sheet (nearly 700 outfalls.); MDE, Prince
George's County NPDES Permit Fact Sheet (more than 4,000
outfalls); MDE, Baltimore City NPDES Permit Fact Sheet
(around 350 outfalls.); see also 40 C.F.R. §
122.26(b)(5), (9) (outlining minimum diameters of pipes in
major MS4 outfalls).
Because of the nature of municipal stormwater discharges,
Congress adopted a flexible approach to the control of
pollutants in MS4s. See 55 Fed.Reg. at 48,038 (The
Congressional Record from 1986 stated not only that " an
end-of-the-pipe treatment technology is not appropriate for
[the MS4] discharge" but also that " [MS4] controls
may be different in different permits." ). Pursuant to
33 U.S.C. § 1342(p)(3)(B)(iii), [447 Md. 99] municipal
stormwater permits " shall require controls to reduce
the discharge of pollutants to the maximum extent
practicable, including management practices, control
techniques and system, design and engineering methods . . .
management practices (" BMPs" ) have been a
long-standing control or effluent limitation in MS4
permits. See 40 C.F.R. § 122.44(k)(2) (BMPs
" control or abate the discharge of pollutants when
[a]uthorized under [33 U.S.C. § 1342(p)]" );
id. § 122.44(k)(3) (BMPs are an appropriate
control when " [n]umeric effluent limitations are
infeasible" ); see also Tualatin
Riverkeepers v. Or. Dep't of Envtl. Quality, 235
Or.App. 132, 230 P.3d 559, 564 (Or. Ct.App. 2010) ("
'Best management practices,' such as those
incorporated in the permits at issue in this case, are a type
of effluent limitation." ). The EPA defined BMPs to mean
" schedules of activities, prohibitions of practices,
maintenance procedures, and other management practices to
prevent or reduce the pollution of 'waters of the United
States.'" 40 C.F.R. § 122.2; cf.
Natural Res. Def. Council, Inc. v. EPA, 808 F.3d
556, 579 (2d Cir. 2015) (" But EPA's narrative WQBEL
[water-quality based effluent limitation] does not qualify as
a BMP, as it is neither a practice nor a procedure." ).
Examples of the types of BMPs the Counties might implement
pursuant to the Permits are infiltration practices and green
Md. 100] Through guidance memos, the EPA has endorsed the use
of BMPs in MS4s for decades but has increasingly recommended
that, where feasible, such permits include numeric effluent
limitations. Interim Permitting Approach for Water-Quality
Based Effluent Limitations in Storm Water Permits, 61
Fed.Reg. 43,761 (1996); EPA, Memorandum on Establishing Total
Maximum Daily Load (TMDL) Wasteload Allocations (WLAs) for
Storm Water Sources and NPDES Permit Requirements Based on
Those WLAs § 3 (2002) [hereinafter " 2002
Memo" ]; EPA, Memorandum on Revisions to the November
22, 2002 Memorandum 4-5 (2010) [hereinafter " 2010
Memo" ]; EPA, Memorandum on Revisions to the November
22, 2002 Memorandum at 4 n.5 (2014) [hereinafter " 2014
Memo" ]. (A " numeric" effluent limitation
" refers to [a] limitation with a quantifiable or
measurable parameter related to a pollutant (or
Maximum Daily Loads (" TMDLs" )
concept of total maximum daily load (" TMDL" )
looms large in this case. We begin by setting
forth its basic purpose, then unpacking its complex
inform. See Am. Farm Bureau Fed'n v.
EPA, 792 F.3d 281, 291 (3d Cir. 2015) (" Our
understanding of [TMDLs] as informational tools is supported
by every case and piece of scholarship to consider them as
well as the language of the Chesapeake Bay TMDL itself."
); see also EPA, Chesapeake Bay TMDL § 1.41, at
1-15 (2010) (" TMDLs are 'primarily informational
tools' that 'serve as a link in an implementation
chain . . . .'" ), available at
Md. 101] TMDLs arise out of a multi-step process that begins
with the establishment of water quality standards ("
WQS" ). See Am. Farm Bureau Fed'n,
792 F.3d at 289 (" TMDLs happen after a state enacts
pursuant to its law (but required by the Clean Water Act)
'water quality standards.'" ). Because the EPA
and the states interact throughout this process, it has been
described as one of " cooperative federalism."
Id. at 288; see Anacostia Riverkeeper,
Inc. v. Jackson, 798 F.Supp.2d 210, 214-17 (D.D.C.
quality standards, as the term itself suggests, protect water
quality. 40 C.F.R. § 130.2(d); COMAR 26.08.02.01(A).
Each state must set water quality standards by assigning a
" use" to a water, such as recreation or fishing,
then developing criteria to protect those uses, as well as
ensuring that higher quality waters do not degrade to the
minimally accepted standard (also known as an
anti-degradation policy). 33 U.S.C. § 1313; COMAR
26.08.02.01(B)(1). All water quality standards are subject to
EPA review, and if the EPA does not approve of them, the EPA
will set those standards itself. 33 U.S.C. § 1313.
of example, the EPA approved a TMDL that MDE submitted for
fecal bacteria for the Non-tidal Cabin John Creek Basin in
Montgomery County in 2007. See MDE, Total Maximum
Daily Loads of Fecal Bacteria for the Non-tidal Cabin John
Creek Basin in Montgomery County, Maryland (Document version:
Oct. 13, 2006) [hereinafter " John Creek Basin
TMDL" ]. These bacteria are microscopic organisms in
animal waste. Fecal bacteria in water can raise the risk of
illness in humans who recreate there. Id. at §
1.0, at 1. To develop the WQS, MDE selected " water
contact recreation and protection of aquatic life and public
water supply" as the use of the water and 126
MPN per 100 milliliters as the criteria.
Id. at § 2.3, at 11 (citing COMAR 26.08.02.08O
and [447 Md. 102] 26.08.02.03-3). This figure (126)
represents a mean density for this pollutant. Id.;
see 40 C.F.R. § 130.2(i) (" [M]ass per time,
toxicity, or [an]other appropriate measure" may be used
to express TMDLs.).
setting WQSs, the states establish effluent limitations in
permits as the primary way to meet the WQSs because, as we
have explained, effluent limitations restrict the discharge
of pollutants. See 33 U.S.C. § 1362(11).
Nevertheless, we note, importantly, that MS4s are not
subject to the requirement of imposing effluent
limitations " necessary to meet water quality
standards." See 33 U.S.C. § 1311(b)(1)(C);
see also Defenders of Wildlife v. Browner,
191 F.3d 1159, 1165 (9th Cir. 1999); cf. 33 U.S.C.
§ 1342(p)(3)(A) (Industrial dischargers must comply with
33 U.S.C. § 1311.). This important point
notwithstanding, Congress requires that " [e]ach State
shall identify those waters within its boundaries for which
the effluent limitations required by [33 U.S.C. § 1311]
are not stringent enough to implement any water quality
standard applicable to such waters." 33 U.S.C. §
where the TMDL comes into play. The TMDL tells a state what
is the threshold amount of a pollutant that a body of water
can tolerate before violating the WQS. See In re
City of Moscow, Idaho, 10 E.A.D. 135, 2001 WL 988721, at
*4 (EAB July 27, 2001) (" A TMDL is a measure of the
total amount of a pollutant from point sources, nonpoint
sources and natural background, that a water quality limited
segment can tolerate without violating the applicable water
quality standards." ); EPA, Chesapeake Bay TMDL §
1.1, at 1-2 (" A TMDL specifies the maximum amount of a
pollutant that a waterbody can receive and still meet
applicable WQS." ).
Md. 103] States must establish TMDLs " at a level
necessary to implement the applicable water quality
standards," 33 U.S.C. § 1313(d)(1)(C), when they
identify those waters for which effluent limitations cannot
implement the WQSs, 33 U.S.C. §
1313(d)(1)(A). As with water quality standards, the
states have the obligation of setting TMDLs and submitting
them to the EPA for approval. See supra MDE, John
Creek Basin TMDL (The EPA approved of MDE's TMDL in March
2007.). If the EPA disapproves of the TMDLs, the EPA will set
them itself. 33 U.S.C. § 1313(d)(2).
this case, wasteload allocations (" WLAs" ) are the
most critical part of the TMDL equation. See 40
C.F.R. § 130.2(i) (A TMDL is " [t]he sum of the
individual WLAs for point sources and LAs [load allocations]
for nonpoint sources and natural background." ). The WLA
represents a water's " loading capacity"
assigned to its " point sources of pollution."
Id. § 130.2(h). Continuing with our example,
MDE set the TMDL for fecal bacteria at 176.36 billion
MPN/day, the LA at 68.17 billion MPN/day, and the WLA at
108.19 billion MPN/day. MDE, John Creek Basin
Md. 104] Although TMDLs are informational tools, of which
WLAs are a part, WLAs are more akin to restrictions.
See Am. Farm Bureau Fed'n v. EPA, 984
F.Supp.2d 289, 328 (M.D. Pa. 2013) (" WLAs are not
permit limits per se ; rather they still require
translation into permit limits . . . ." ) (citation
omitted) (internal quotation marks omitted) (emphasis in
original), aff'd, 792 F.3d 281 (3d Cir. 2015).
Under 40 C.F.R. § 122.44(d)(1)(vii)(B), permitting
authorities must ensure that effluent limitations " are
consistent with the assumptions and requirements" of any
conclude our introduction of TMDLs by noting that MS4s are
subject to the MEP standard under 33 U.S.C. § 1342. MS4s
are not, however, required to impose effluent limitations
necessary to meet water quality standards. The CWA still
requires Maryland to set water quality standards and
TMDLs--subject to the EPA's approval. Flowing from this
obligation is the requirement that MS4s are subject to
effluent limitations that are consistent with WLAs of
Chesapeake Bay TMDL
will discuss in more detail, the Permits require the Counties
to take actions to make progress in meeting the WLAs of many
EPA-approved TMDLs. By far, though, the [447 Md. 105]
most critical TMDL in this case is the Chesapeake Bay TMDL
(" Bay TMDL" ).
as a national treasure, the Chesapeake Bay is the largest
estuary in the United States, a product of flooding from the
Susquehanna River over thousands of years. Alice Jane
Lippson, The Chesapeake Bay in Maryland: An Atlas of Natural
Resources 2 (Johns Hopkins University Press 1973). Over 2,000
species of animals and plants reside in the Chesapeake Bay.
Alice Jane Lippson & Robert L. Lippson, Life in the
Chesapeake Bay viii (Johns Hopkins University Press 1984).
These include phytoplankton, the blue crab, and striped bass,
among many, many others. Lippson, The Chesapeake Bay in
Maryland, supra at 14, 26, 36. In addition to
housing much wildlife, the Chesapeake Bay is a shipping and
commerce hub and a source of recreation. Chesapeake Bay
Program, Chesapeake Bay: Introduction to an Ecosystem 2
activity, however, threatens this complex ecosystem. "
Excess sediment and nutrients endanger the Bay's water
quality." Id. at 3-4. Such threats include:
depriving species of oxygen; delivering chemicals which
collect in animal tissue; and even destroying habitats
because sunlight cannot reach critical underwater grasses
where species reside. Id.
is, then, no underestimating the importance of the
restoration of the Chesapeake Bay in Maryland. See
Am. Farm Bureau, 984 F.Supp.2d at 298 (" [The
Bay] has been [447 Md. 106] described as one of the most
biologically productive ecosystems in the world," and,
along with its watersheds, " add[s] ecological,
economic, recreational, historic, and cultural value to the
restore the Bay, however, has been a prolonged, frustrated
process. See id. (The Bay TMDL " is not a new
or recent idea," and thus, " it would be improper
to view the Final TMDL in a vacuum as a single, isolated
effort to restore water quality to the Chesapeake Bay."
). Some of these restoration efforts include the Chesapeake
Bay Agreement in 1980, another agreement in 1987, amendments
to the agreement in 1992, and the Chesapeake 2000 Agreement.
Department of Legislative Services, Office of Policy
Analysis, Chesapeake Bay Restoration and the Tributary
Strategy: An Analysis of Maryland's Efforts to Meet the
Nutrient and Sediment Reduction Goals of the
Chesapeake 2000 Agreement 3-4 (2007).
established the Bay TMDL in December 2010. See
Am. Farm Bureau Fed'n, 792 F.3d at 290 ("
As noted, for the Chesapeake Bay the relevant states and the
EPA agreed that the EPA would draft the TMDL in the first
instance." ). It has survived legal challenges before
the U.S. District Court for the Middle District of
Pennsylvania as well as the Third Circuit.
See Am. Farm Bureau Fed'n, 984
F.Supp.2d at 294; Am. Farm Bureau Fed'n, 792
F.3d at 287. These courts have noted that the efforts to
restore the Chesapeake Bay extend back decades, and that the
development of the Bay TMDL itself has been a decade-long
process. Am. Farm Bureau Fed'n, 984 F.Supp.2d at
299; Am. Farm Bureau Fed'n, 792 F.3d at 291.
TMDL provides information pertaining to pollution reduction
for nitrogen, phosphorus and sediment in the Chesapeake [447
Md. 107] Bay and applies to the District of Columbia and the
six " Bay" states, including Maryland. EPA,
Chesapeake Bay TMDL at ES-1.
delving into Maryland's role in the formation of the Bay
TMDL, we must discuss the " critical and valuable"
role that modeling played in the Bay TMDL's development.
EPA, Chesapeake Bay TMDL at ES-5. " Modeling is an
approach that uses observed and simulated data to replicate
what is occurring in the environment to make future
predictions." Id. " A model 'is an
abstraction from and simplification of the real
world.'" Am. Farm Bureau, 984 F.Supp.2d at
340 (citation omitted). Models are essential when one seeks
to study " ecosystems that are too large or complex for
real-world monitoring," such as the Chesapeake Bay and
its watersheds. Chesapeake Bay Program, About the Bay
Program: Modeling, available at
visited Feb. 9, 2016) [hereinafter CBP: Modeling].
prominent component in the modeling of the Bay TMDL was the
Phase 5.3 Chesapeake Bay Watershed Model [" Phase 5.3
Model" ]. EPA, Chesapeake Bay TMDL, at
5-19. " The [447 Md. 108] Phase 5.3
Model is the most recent of a series of increasingly refined
versions of the Chesapeake Bay Watershed Model." EPA,
Chesapeake Bay Phase 5.3 Community Watershed Model §
1.2.1, at 1-13 (2010), available at
. The Phase 5.3 Model simulates the
" loading and transport of nitrogen, phosphorus, and
sediment from pollutant sources throughout the Bay
watershed." EPA, Chesapeake Bay TMDL, at 5-20.
Additionally, this model provides " estimates of
watershed nitrogen, phosphorus, and sediment loads resulting
from various management scenarios." Id.
models are not " perfect forecasts," however,
modeling is " part of a broader toolkit," including
monitoring, " to gain the highest possible level of
accuracy." CBP: Modeling. As the EPA explained: "
The Bay modeling framework takes advantage of decades of
atmospheric deposition, streamflow, precipitation, water
quality, biological resource, and land cover monitoring
data" as well as " tracking and reporting of the
implementation of pollution load reduction best management
practices." EPA, Chesapeake Bay TMDL, at § 5.1,
5-1-5-2. These resources allowed the EPA to calibrate its
the Bay TMDL exists in significant part as a result of
modeling, and because of how prevalent modeling is in TMDL
formulation, MDE incorporated modeling into the Permits.
incorporated by reference a document the agency published,
called Accounting for Stormwater Wasteload Allocations and
Impervious Acres Treated, Guidance for National Pollutant
Discharge Elimination System Stormwater Permits [447 Md. 109]
(" the Guidance" ). As the name suggests,
the document serves dual purposes: the Counties can assess
progress in achieving WLAs and also assess restoration of
impervious surface areas through a credits-to-acres
approach. In the Guidance, MDE sets forth
acceptable models that the Counties can use, including,
Maryland's Assessment and Scenario Tool ("
MAST" ). MDE, Guidance at 2. The Guidance
includes the pollutant rates for the Bay TMDLs--Total
Nitrogen (" TN" ), Total Phosphorus ("
TP" ), and Total Suspended Sediment (" TSS"
)--and requires that the Counties use these pollutant rates
together with land use data to calculate baseline stormwater
loads. Id. at 2-3. As the document explains, "
[t]hese pollutant loads are specific to the  Bay
TMDL." Id. at 2. But the Counties may use the
principles and methods in the Guidance " for any EPA
approved TMDL." Id. at 1.
Watershed Implementation Plan (" WIP" )
developed the Bay TMDL to ensure that the Bay jurisdictions
would put in place " all pollution control measures
needed to fully restore the Bay and its tidal rivers" by
2025. EPA, Chesapeake Bay TMDL at ES-1. The EPA approved the
Bay TMDL " only after" determining that each
jurisdiction provided " reasonable assurance" that
it would meet established pollutant reductions. Am. Farm
Bureau Fed'n, 792 F.3d at 291. The Bay jurisdictions
set forth their strategies for meeting pollutant reductions
in Watershed Implementation Plans (" WIPs" ).
are " roadmaps" setting forth a plan for how and
when a jurisdiction will reach the pollution reduction goals
in the Bay TMDL. EPA, Chesapeake Bay TMDL, at ES-8. The EPA
described these roadmaps as the " cornerstone" that
[447 Md. 110] ensured the States were accountable in
achieving pollution reductions. Id. Notably, the EPA
expressed no concerns about Maryland's Final
WIP, whereas the EPA had to implement
backstop allocations and adjustments in other Bay
jurisdictions so that the EPA had reasonable assurance that
all jurisdictions would achieve necessary reductions.
See EPA, Chesapeake Bay TMDL Executive Summary,
ES-10--ES-13 (Dec. 29, 2010) [hereinafter " Bay TMDL
WIP lists restoration of " twenty percent of the
counties' impervious surface area that is not already
restored to the maximum extent practicable (MEP)" in the
" key elements" supporting the reasonable assurance
of the implementation of the WIP. Phase I WIP at 5-30. The
elements also include the adaptive management approach
whereby additional or alternative practices are implemented
if existing programs are not meeting target reductions.
Stormwater Management History
addition to an explication of the federal permitting system,
NPDES, and the complex components arising out of it, such as
TMDLs, we also set forth Maryland's stormwater [447 Md.
111] management program, which has evolved since its
inception in the 1980s, and which is informative for purposes
of analyzing the Permits.
1982, the General Assembly enacted laws " to reduce as
nearly as possible the adverse effects of stormwater
runoff." Maryland Code (1982, 2007 Repl. Vol.), §
4-201 of the Environment Article (" EN" );
see H.B. 1091, 1982 Gen. Assemb. Reg. Sess. (Md.
1982). As a result, each county and municipality in Maryland
was required for the first time to " adopt ordinances
necessary to implement a stormwater management program"
by July 1, 1984. See EN § 4-202. Then
authorized by the General Assembly, the Department of Natural
Resources issued regulations setting forth minimum control
requirements and design criteria for the counties and
municipalities. See 10 Md. Reg. 881, 884-85 (May 13,
1983) (to be codified at COMAR 08.05.05). The
regulations fostered the " primary goal" of "
maintain[ing] after development, as nearly as possible, the
predevelopment runoff characteristics" of the land.
See EN § 4-203(b)(1); see also EN
§ 4-204(a) (Development of land is prohibited without
submitting a stormwater management plan and obtaining the
municipality's or county's approval of the plan.)
entered a new phase of stormwater management in the early
2000s. Pursuant to EN § 4-203(b), MDE adopted
regulations to " rectify the programmatic
shortcomings" of then-existing regulations that had
provided " sparse guidance" on " water quality
enhancement." 27 Md. Reg. 1167, 1168 (June 16, 2000) (to
be codified at COMAR 26.07.02). Amending the stormwater
regulations, MDE intended to " provide water quality
treatment of up to 90 percent of the average annual rainfall
throughout the State, establish ground water recharge
standards, and outline a channel erosion control
strategy," as well as " promote environmentally
friendly site design." Id. To fulfill this
purpose, MDE incorporated by [447 Md. 112] reference the 2000
Maryland Stormwater Design Manual (" the Manual" ).
Id. at 1167, 1169. MDE required the
counties and municipalities to revise their ordinances to
incorporate the Manual's policies and practices by July
1, 2001. Id. at 1170.
Manual " provide[d] designers a general overview on how
to size, design, select and locate BMPs at a new development
site to comply with State stormwater performance
standards." Center for Watershed Protection ("
CWP" ) & MDE, Manual, § 1.3, at 1.16. There are 14
performance standards, including the water quality volume
standard (" WQv" ). Id. § 1.2, at
stormwater management phase began when the General Assembly
required MDE to mandate the use of environmental site design
(" ESD" ) in 2007. H.B. 786, Gen. Assemb. Reg.
Sess. (Md. 2007). ESD is best understood as those practices,
such as " small-scale stormwater management practices,
nonstructural techniques, and better site planning,"
that " mimic natural hydrologic runoff characteristics
and minimize the impact of land development on water
resources." EN § 4-201.1(b); see, e.g.,
note 9 (green roofs). MDE implemented regulations to this
effect and explained that " [t]he goal of the
regulations is to maintain after development as nearly as
possible, the predevelopment runoff characteristics of the
site being developed using ESD to the MEP." 35 Md. Reg.
2191 (Dec. 5, 2008) (to be codified at COMAR 26.17.02).
issued several series of MS4 permits to the Counties that
preceded the Permits before us today. See MDE, NPDES
MS4 Permit Montgomery County Fact Sheet (2008) [447 Md. 113]
(The first two permits were issued in 1996 and 2001.); MDE,
Basis for Final Determination to Issue Prince George's
County's NPDES MS4 Permit (2013) (The first three permits
were issued in 1993, 1999, and 2004.); MDE, Basis for Final
Determination to Issue Baltimore County's NPDES MS4
Permit (2013) (The first three permits were issued in 1994,
2000, and 2005.); MDE, Basis for Final Determination to Issue
Anne Arundel County's NPDES MS4 Permit (2013) (The first
three permits were issued in 1993, 1999, and 2004.); MDE,
Basis for Final Determination to Issue Baltimore City's
NPDES MS4 Permit (2013) (The first three permits were issued
in 1993, 1999, and 2005.).
issue here are five-year term Permits MDE most recently
issued: to Montgomery County in February 2010, to Baltimore
County in December 2014, to Baltimore City in December 2013,
to Prince George's County in January 2014, and to Anne
Arundel County in February 2014.
Water Groups challenge the Permits in several respects,
namely, (1) the requirement to restore impervious surface
area, (2) the requirement to submit plans for TMDLs, (3) the
monitoring requirements, and (4) the public's ability to
participate in the development of the Permits.
these provisions are new and therefore represent an increase
in responsibility on the Counties to maintain and improve the
quality of their waters. See, e.g., MDE, Basis for
Final Determination to Issue Anne Arundel County's NPDES
MS4 Permit (2013) (" These meetings resulted in the
addition of more stringent conditions to Anne Arundel
County's stormwater permit, in large part due to a
regional and growing focus on restoring Chesapeake Bay."
); id. (" New requirements in the permit will
include . . . developing restoration plans to meet stormwater
WLAs for impaired waters." ); MDE, NPDES Montgomery
County Stormwater Permit Response to Formal Comments at 2
(2009) (" MDE believes that [447 Md. 114] this current
municipal stormwater permit will force Montgomery County to
make major strides toward controlling urban runoff better
than ever before. New conditions such as trash abatement
jurisdiction-wide and requiring an additional 20% of the
County's impervious area to be restored are major
additions." );  MDE, Maryland's 2006 TMDL
Implementation Guidance for Local Governments i (2006)
(" Until recently, Maryland has focused primarily on
TMDL development, which establishes limits on pollutant
loads. Now the State is moving into the implementation phase
. . . ." ).
discussing these Permit provisions, we note additional Permit
requirements that illustrate the breadth of the Counties'
obligations. The Counties must implement management programs
" to control stormwater discharges to the maximum extent
practicable." These programs include a stormwater
management program (" SWMP" ) and an erosion and
sediment control program in accordance with state law; an
" illicit discharge detection and elimination"
program; requirements to reduce trash; obligations on the
Counties to reduce pollutants associated with maintenance
activities and on municipal facilities to submit pollution
prevention plans; as well as a requirement to engage in
public outreach activities to reduce stormwater pollution.
Permits also require the Counties to engage in thorough
analyses of the water quality of their watersheds. Among
other things, the watershed assessments oblige the Counties
to identify and prioritize water quality improvement
also ensured that the Counties cannot use lack of adequate
funding as a defense for failure to comply with Permit terms.
The Permits explain that " [l]ack of funding [447 Md.
115] does not constitute a justification for noncompliance
with the terms of this permit."  To this end, the
General Assembly enacted EN § 4-202.1 in 2012, requiring
the Counties " to adopt local laws or ordinances
necessary to establish an annual stormwater remediation fee
and a local watershed protection and restoration fund to
provide financial assistance for the implementation of local
stormwater management plans." H.B. 987, 2012 Gen.
Assemb. Reg. Sess. (Md. 2012); see also EN §
4-202.1(a)(1) (This " section applies to a county or
municipality that is subject to a [NPDES Phase I MS4
permit]." ). MDE had investigated the costs of
meeting the Bay TMDL and commissioned a study that revealed
that " stormwater BMPs likely represent the largest
costs to local governments in implementing the TMDL."
H.B. 987, 2012 Gen. Assemb. Reg. Sess. (Md. 2012).
Permits also contain annual reporting requirements for: (1)
the components of the stormwater management programs, and (2)
data pertinent to the assessment of progress in implementing
the Permit requirements, such as impervious surfaces and
pollutant load reductions. MDE will review the Counties'
reports to assess " progress toward meeting WLAs
developed under EPA approved TMDLs" and the
effectiveness of the programs in " reducing the
discharge of pollutants to the MEP to protect water
quality." MDE will require BMP and program modifications
if the Counties fail to comply with the Permit or show
Permits also contain provisions setting forth sanctions for
the violation of Permit conditions, including civil and
criminal penalties. See, e.g., Montgomery County
NPDES Permit Part VI.C (" Failure to comply with a
permit provision [447 Md. 116] constitutes a violation of the
CWA and is grounds for enforcement action; permit
termination, revocation, or modification; or denial of a
permit renewal application." ).
Court and Court of Special Appeals Opinions
§ 1-601 provides for judicial review of MDE's final
determination to issue a permit. The Water
Groups challenged the Permits in the
various counties where MDE issued them.
Circuit Court for Montgomery County remanded for MDE to
revise the Permit in accordance with its opinion and order.
In a reported opinion, the Court of Special Appeals affirmed.
Md. Dep't of the Env't v. Anacostia
Riverkeeper, 222 Md.App. 153, 157, 112 A.3d 979, 981
(2015), cert. granted, 443 Md. 734, 118 A.3d 861.
MDE filed a petition for writ of certiorari, which we
Circuit Court for Baltimore County, the Circuit Court for
Anne Arundel County, and the Circuit Court for Prince
George's County affirmed MDE's decision to issue
those Permits. The Water Groups filed notices of appeal to
the Court of Special Appeals and, upon MDE's motion, the
Court of Special Appeals consolidated these three cases. MDE
then filed a petition for writ of certiorari to this Court
with questions nearly identical to those MDE submitted in its
petition for writ of certiorari with respect to the
Montgomery County Permit.
the Circuit Court for Baltimore City also affirmed MDE's
decision to issue the Baltimore City Permit. The [447 Md.
117] Water Groups filed a notice of appeal, and the Mayor &
City Council of Baltimore (" Baltimore City" )
filed a petition for writ of certiorari with a request that
we consider this petition in conjunction with MDE's
petitions. We granted the City's petition.
Water Groups state in their brief, " the underlying
Permits are substantively identical" and " are
affected by the same legal defects." We agree that the
Permits are so substantively similar that we will analyze the
agreed upon questions brought before the Court with respect
to all the challenged Permits. We have slightly rephrased the
1. Did the MS4 permits issued by MDE for the counties'
municipal storm sewer system appropriately incorporate by
reference publicly available materials and was the
requirement for restoration of 20% of pre-2002 developed
impervious surfaces specific, measurable, and enforceable?
2. Was MDE's final decision to issue the permits with a
20% restoration requirement based upon the State's
Chesapeake Bay TMDL strategies, and a reporting requirement
to establish strategies to address wasteload allocations,
supported by substantial evidence?
3. Do the provisions of the MS4 permits that require that the
public have an opportunity to review and comment on
restoration plans intended to meet the wasteload allocations
established for the permittees under applicable total maximum
daily loads satisfy public participation requirements?
4. Do the provisions of the MS4 permits satisfy federal
uphold MDE's decision to issue the Permits on all
grounds. Thus, we reverse the judgment of the Court of
Special Appeals, which did not uphold the Montgomery County
Permit, and we affirm the judgments of the circuit courts,
which upheld the Permits in Anne Arundel County, Baltimore
City, Baltimore County, and Prince George's County.
Md. 118] STANDARD OF REVIEW
2009, challenges to the issuance or denial of a discharge
permit were subject to a contested case hearing. Md. Code
(1984, 2014 Repl. Vol.), § 10-222 of the State
Government Article (" SG" ), which is part of
Maryland's Administrative Procedure Act, delineates the
grounds upon which a court can reverse an agency decision in
a contested case. Specifically, SG § 10-222 provides
that a court can reverse an agency decision in a contested
case that " is unsupported by competent, material, and
substantial evidence in light of the entire record as
submitted" or that " is arbitrary or
2009, the General Assembly changed the procedures for
challenging a discharge permit. EN § 1-601 now permits
direct judicial review of agency permitting decisions without
a contested case hearing. Although this statute does not set
forth a standard of review, the substantial evidence and
arbitrary and capricious standards apply where an "
organic statute" authorizes judicial review without a
contested case hearing and does not set forth a standard of
review. See Supervisor of Assessments of Carroll
Cnty. v. Peter & John Radio Fellowship, Inc., 274 Md.
353, 355, 335 A.2d 93, 94 (1975) (" Our cases have held
that where no scope of review is thus provided, decisions of
an administrative body will not be disturbed on appeal unless
they are not supported by substantial evidence or are
arbitrary, capricious or unreasonable." ) (citations
omitted); Med. Waste Assocs., Inc. v. Md. Waste Coal.,
Inc., 327 Md. 596, 621, 612 A.2d 241, 253 (1992) (
" In an action for judicial review of an administrative
decision granting a permit, however, the court determines not
only whether the agency's decision to issue the permit
was in accordance with law, but also whether the particular
administrative decision was arbitrary, capricious or
unsupported by substantial evidence in light of the record as
a whole." ). Thus, even though all challenges going to
the merits of the Permits in these consolidated cases
originated in the Circuit Courts, we [447 Md. 119] will
review MDE's decision to issue the Permits under the
substantial evidence and arbitrary and capricious standards
the substantial evidence standard of review to a case where
no contested case hearing took place may seem anomalous
because there is no formal record that was presented before
an administrative law judge. EN § 1-606, however,
expressly details the documents that can be included in a
record. EN § 1-606(c)(1)-(9). For example, EN §
1-606 stipulates that any draft permit, comments submitted to
MDE [447 Md. 120] during the public comment period,
transcripts of public hearings on the permit application, and
responses to submitted comments constitute part of the
administrative record. Thus, we are essentially reviewing the
same record that we would have examined, excluding the
administrative law judge's decision, had the merits of
this case been subject to a contested case proceeding.
Accordingly, our review of the issuance of the Permits fits
within the substantial evidence standard of review
contemplated by SG § 10-222.
review for substantial evidence, we ask " whether a
reasoning mind reasonably could have reached the factual
conclusion the agency reached." Najafi v. Motor
Vehicle Admin., 418 Md. 164, 173, 12 A.3d 1255, 1261
(2011). We should accord deference " 'to the
agency's fact-finding and drawing of
inferences'" when the record supports them.
Id. (citation omitted); see Mayor &
Aldermen of City of Annapolis v. Annapolis Waterfront
Co., 284 Md. 383, 399, 396 A.2d 1080, 1089 (1979)
(" The court may not substitute its judgment on the
question whether the inference drawn is the right one or
whether a different inference would be better supported. The
test is reasonableness, not rightness." ) (citation and
internal quotation marks omitted). Moreover, we shall review
the agency's decision " 'in the light most
favorable to it.'" Najafi, 418 Md. at 173,
12 A.3d at 1261. Finally, we must accord an agency great
deference regarding factual questions involving scientific
matters in its area of technical expertise. Bd. of
Physician Quality Assurance v. Banks, 354 Md. 59, 69,
729 A.2d 376, 381 (1999) (" [T]he expertise of the
agency in its own field should be respected." ).
characterized the arbitrary and capricious standard of review
as one that is " extremely deferential." Harvey
v. Marshall, 389 Md. 243, 299, 884 A.2d 1171, 1205
(2005). In reviewing the issuance of an NPDES permit, the
U.S. Court of Appeals for the Second Circuit quoted language
derived from Motor Vehicle Mfrs. Ass'n v. State Farm
Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983), 103 S.Ct.
2856, 77 L.Ed.2d 443--the [447 Md. 121] United States Supreme
Court's leading case on the arbitrary and capricious
To determine whether the agency's actions were "
arbitrary and capricious," we consider whether the
agency 'relied on factors which Congress has not intended
it to consider, entirely failed to consider an important
aspect of the problem, offered an explanation for its
decision that runs counter to the evidence before the agency,
or is so implausible that it could not be ascribed to a
difference in view or the product of agency expertise.'
Natural Res. Def. Council, 808 F.3d at 569
(citations and quotation marks omitted). The court also
elaborated that " [w]e must be 'satisfied from the
record that the agency . . . examine[d] the relevant data and
articulate[d] a satisfactory explanation for its
action'" and that it " afford[ed] the
agency's decision greater deference regarding factual
questions involving scientific matters in its area of
technical expertise." Id. (quoting State
Farm, 463 U.S. at 43) (citations and internal quotation
marks omitted). The Second Circuit's articulation of the
arbitrary and capricious standard is in accord with
Maryland's treatment of this standard as one that is
highly deferential. See Harvey, 389 Md. at
299, 884 A.2d at 1205. We are therefore mindful of the Second
Circuit's explanation of the principles underlying the
arbitrary and capricious standard when applying that standard
to this case.
Md. 122] In addition, we will review an agency decision for
an error of law. When our review concerns a legal question,
we apply less deference to the agency's conclusions.
HNS Dev., LLC v. People's Counsel for Balt.
Cnty., 425 Md. 436, 449, 42 A.3d 12, 20 (2012). We
refuse to uphold an agency decision " premised solely
upon an erroneous conclusion of law." Id.
(citation omitted) (internal quotation marks omitted).
Otherwise, we ordinarily should give " considerable
weight" to an agency's " interpretation and
application of the statute which [it] administers."
W.R. Grace & Co. v. Swedo, 439 Md. 441, 453, 96 A.3d
210, 217 (2014); John A. v. Bd. of Educ. for Howard
Cnty., 400 Md. 363, 381-82, 929 A.2d 136, 147 (2007)
(" In reviewing an agency's legal conclusions, it is
a fundamental principle of administrative law that a
reviewing court should not substitute its judgment for the
expertise of those persons who constitute the administrative
I: The 20% Restoration Requirement
Permits require, by the end of the five-year term, that the
Counties restore 20% of the impervious surface areas in their
watersheds that have not been restored to the MEP. This
requirement " uses percent impervious cover in a
watershed as a surrogate TMDL target." ENSR, Pilot TMDL
Applications Using the Impervious Cover Method § 1.0, at
1-1 (2005). Like so much of this case, we must unpack the
science before we analyze the parties' arguments.
develop on land, science has shown us that we profoundly
impact our waters. Consider, for example, when "
[t]rees, meadow grasses, and agricultural crops that had
intercepted and absorbed rainfall are removed . . . ."
CWP & MDE, Manual, § 1.1, at 1.3. Problematically,
" [c]leared and graded sites erode, are often severely
compacted, and can no longer prevent rainfall from being
rapidly converted into stormwater runoff." Id.
These kinds of sites are known as impervious surfaces,
surfaces " that do not allow stormwater to infiltrate
into the ground," such as " rooftops, driveways,
[447 Md. 123] sidewalks, or pavement." EN §
4-201.1(d). " Impervious surfaces accumulate
pollutants deposited from the atmosphere," pollutants
which are " rapidly delivered to downstream waters"
during storms. CWP & MDE, Manual, § 1.1.1, at 1.5. The
purpose of the 20% restoration requirement, then, is to use
stormwater management practices to restore the natural,
beneficial processes in our environment that we have changed
by developing impervious surfaces.
other words, the 20% restoration requirement is a surrogate
because the requirement does not control pollution reduction
directly. See ENSR, Pilot TMDL Applications Using
the Impervious Cover Method § 1.0, at 1-1. Rather, it is
through restoring impervious surfaces with management
practices that the Counties will reduce pollution. See,
e.g., CWP & MDE, Manual, § 1.2, at 1.13 ("
[Management practices] shall be designed to remove 80% of the
average annual post development total suspended solids load
(TSS) and 40% of the average annual post development total
phosphorus load (TP)." ).
Maximum Extent Practicable
Water Groups argue that the 20% restoration requirement is
too opaque to comply with 33 U.S.C. §
1342(p)(3)(B)(iii), the MEP standard. They so argue because,
they contend, MDE " failed to provide a specific
performance standard for restoration activities" or a
" numeric limitation . . . for what pollution reductions
must be accomplished by the permittees' twenty-percent
restoration efforts." They also argue that MDE failed to
explain what impervious surface is " not restored to the
disagree because (1) the applicable law does not impose a
specific performance standard on MS4s and (2) MDE did
actually select a performance standard for the Counties to
adhere to. 33 U.S.C. § 1342(p)(3)(B)(iii) states:
Permits for discharges from municipal storm sewers shall
require controls to reduce the discharge of pollutants to the
maximum extent practicable, including management practices,
control techniques and system, design and engineering
methods, and such other provisions as the Administrator or
[447 Md. 124] the State determines appropriate for the
control of such pollutants.
the text, we discern that Congress established a broad
requirement for MS4s. The list of required controls is not
exclusive. See 55 Fed.Reg. at 48,038 (" [MS4]
controls may be different in different permits." ). And
the purpose of the controls--reducing the discharge of
pollutants--exists alongside the flexible, undefined standard
" to the maximum extent practicable." See
City of Abilene v. EPA, 325 F.3d 657, 659-60 (5th
Cir. 2003); Natural Res. Def. Council, Inc. v. N.Y. State
Dep't of Envtl. Conservation, 25 N.Y.3d 373, 406, 13
N.Y.S.3d 272, 34 N.E.3d 782 (N.Y. 2015) (Rivera, J.,
dissenting in part) ( " The CWA does not define the
maximum extent practicable standard. However, it appears to
provide broad authority to agencies to control stormwater
pollution." ); 55 Fed.Reg. at 48,038 ( " In
enacting section 405 of the WQA [Water Quality Act], Congress
recognized that permit requirements for [MS4s] should be
developed in a flexible manner to allow site-specific permit
conditions to reflect the wide range of impacts that can be
associated with these discharges." ).
U.S.C. § 1342(p)(3)(B)(iii) imposes no minimum standard
or requirement on MDE other than to establish controls for
MS4s to reduce the discharge of pollutants. See
Natural Res. Def. Council, Inc. v. EPA, 966 F.2d
1292, 1308 (9th Cir. 1992) (" Congress did not mandate
[in § 1342(p)(3)(B)(iii)] a minimum standards approach
or specify that EPA develop minimal performance requirements.
. . . . Congress could have written a statute requiring
stricter standards, and it did not." ). Thus, we reject
the Water Groups' argument that MDE committed legal error
by " fail[ing] to provide a specific performance
standard for restoration activities." 
Md. 125] Moreover, MDE tethered restoration to the practices
in the Manual, which MDE incorporates into the Permits by
reference. See Part III.E (" These management
programs are designed to control stormwater discharges to the
maximum extent practicable . . . ." ); Part III.E.1
(" At a minimum, the County shall . . . [i]mplement the
stormwater management . . . practices found in the [Manual] .
. . ." ). The Manual explains that the list of
acceptable stormwater management practices is tied to the
WQv. " The Water Quality Volume (denoted as the WQv) is
the storage needed to capture and treat the runoff from 90%
of the average annual rainfall." CWP & MDE, Manual,
§ 2.1, at 2.2. The Manual further explains that the
" WQv is directly related to the amount of impervious
cover created at a site." Id. In other words,
MDE chose a standard that relates to the very problem the 20%
restoration requirement serves to abate: the increase in
stormwater runoff and the discharge of pollutants because of
the increase in impervious surfaces. See CWP & MDE,
Manual, § 1.1., at 1.4 (" As can be seen, the
volume of stormwater runoff increases sharply with impervious
cover." ). Thus, the record reflects that MDE has
established a performance standard, WQv, that defines as
acceptable those practices the Counties may choose from to
fulfill the 20% restoration requirement. See id.
§ 2.7 (Acceptable Urban BMP Options).
Md. 126] Moreover, our discussion of restoration is
instructive as to why, despite the Water Groups'
contention, the " impervious surface area that is not
restored to the MEP " is sufficiently clear and
measurable. (Emphasis added.) The area that is not restored
to the MEP is the area without the restoration controls
described in the Manual. Moreover, the Manual explains that
impervious area refers to an area " that does not have
vegetative or permeable cover." CWP & MDE, Manual,
§ 2.1, at 2.4. Put together, the " impervious
surface area that is not restored to the MEP" refers to
a defined type of area (impervious surface) lacking a type of
stormwater management control (the BMPs in the Manual). By
way of example, previous MS4 reports delineate these criteria
so that MDE can evaluate whether Montgomery County (in this
example) installed the required controls. See
Montgomery County Department of Environmental Protection,
Annual Report for 2006 NPDES MS4 Permit F2, at III-64;
see also 33 U.S.C. § 1342(p)(3)(B)(iii) (MS4
permits " shall require controls" such as
33 U.S.C. § 1342(p)(3)(B)(iii) does not require a
specific performance standard, and because the concepts of
restoration and impervious surface " not restored to the
MEP" are sufficiently clear as to the controls that the
Counties must install, the 20% restoration requirement in the
Permits complies with the MEP standard. See 33
U.S.C. § 1342(p)(3)(B)(iii).
Substantial Evidence and Arbitrary and Capricious
Water Groups also argue that MDE has not explained why it
selected 20% as the restoration goal or how this Permit
provision will promote necessary pollution reduction. The
Water Groups contend that MDE ineffectively justifies its
choice based on the Bay TMDL because the Permits do not
assure that the Counties will achieve the Bay TMDL's
objectives or reductions. Even accepting a connection between
the 20% restoration requirement and the Bay TMDL, the Water