                        ENVIRONMENT
LAND USE & PLANNING – GROWTH TIERS – WHETHER A LOCAL
   JURISDICTION IS PROHIBITED FROM AUTHORIZING
   MAJOR SUBDIVISIONS SERVED BY SEPTIC SYSTEMS IF THE
   JURISDICTION’S GROWTH TIERS DO NOT COMPLY WITH
   THE STATUTORY CRITERIA – WHETHER THE STATE MUST
   ENFORCE VIOLATIONS OF THE STATUTE
                        February 15, 2019
The Honorable Kumar P. Barve
House of Delegates of Maryland
      You have asked for our opinion on two questions regarding
the Sustainable Growth and Agricultural Preservation Act of 2012
(the “Act”). See 2012 Md. Laws, ch. 149. The Act was passed in
response to a federal mandate under the Clean Water Act that
required Maryland to demonstrate how it would reduce nutrient
pollution to the Chesapeake Bay, including how it would reduce
nitrogen discharges from on-site sewage disposal systems, more
commonly known as “septic systems” or “septics.” 2012 Md.
Laws, ch. 149, Preamble; see also U.S. Environmental Protection
Agency’s Interim Expectations for the Phase III Watershed
Implementation Plans (Jan. 2017 Interim Version) (“Phase III
Interim Letter”). In an effort to fulfill that mandate, the Act
effectively requires that local jurisdictions wishing to authorize
certain types of major residential subdivisions—especially major
subdivisions on septics—must first adopt a map of up to four
“growth tiers.” Those growth tiers, broadly speaking, describe the
type of development that may occur in each “tier” and set the
method of sewage treatment that may be used for residential
subdivisions within each tier. See Md. Code Ann., Land Use
(“LU”) § 1-502; Md. Code Ann., Envir. (“EN”) § 9-206. A local
jurisdiction that does not adopt tiers “in accordance with” the Act
is prohibited, among other things, from authorizing a major
residential subdivision served by septics anywhere in the
jurisdiction. EN § 9-206(f). Instead, such a local jurisdiction may
authorize a major subdivision only if the subdivision will be served
by public sewer and is located in an area that meets the criteria for
“Tier I” land. See EN § 9-206(f)(2).

      According to your request, one local jurisdiction has adopted
growth tiers that do not meet the Act’s criteria for determining
which area should be included in which tier. See LU § 1-508
(setting those criteria). Based on that understanding, you ask two
questions, which we have rephrased slightly:

                                 3
4                                                       [104 Op. Att’y

           1. Is a local jurisdiction with a noncompliant
           growth tier map prohibited from authorizing a
           major residential subdivision on septic
           systems?

           2. Does the Act, or any other State law,
           compel the State to enforce violations of the
           Act?

      With respect to your first question, it is our opinion that a local
jurisdiction with a noncompliant growth tier map is generally
prohibited from approving a major residential subdivision unless
the subdivision is served by public sewer and is located in a Tier I
area. Thus, in such a jurisdiction, major subdivisions on septics
generally would not be permitted, even in areas where they would
otherwise be permissible had the locality adopted a compliant tier
map. Under EN § 9-206(f), a local jurisdiction may approve major
subdivisions other than those on public sewer in a Tier I area only
if the jurisdiction has adopted a tier map “in accordance with” the
Act or, in other words, has adopted a map that complies with the
Act’s criteria for mapping the growth tiers. A noncompliant tier
map does not meet that condition. It is possible, however, that a
noncompliant tier map with minor errors or inaccuracies might
substantially comply with the Act under limited circumstances.

      With respect to your second question, no State law “compels”
the State to bring an enforcement action directly against a local
jurisdiction for violating the Act. However, the Maryland
Department of the Environment (“MDE”) likely has authority to
disapprove certain applications, permits, and plans related to water
and sewer issues when those applications, permits, and plans
conflict with the Act. To take just one example, it appears that
MDE must at least consider compliance with the Act as part of the
process for evaluating permits to construct waste-disposal systems
and would have little, if any, discretion to overlook a noncompliant
tier map when reviewing a permit application to build a septic
system for a major residential subdivision. In that sense, MDE is
charged with enforcing the Act. Moreover, MDE has broad
discretionary authority to enforce violations of Title 9, Subtitle 2 of
the Environment Article, including the provisions of the Act that
prohibit local jurisdictions from authorizing major subdivisions on
septic systems unless the jurisdiction has complied with the Act’s
tier-mapping criteria. Although that power is discretionary and
does not “compel” enforcement, the failure of local jurisdictions to
comply with the Act could risk breaking Maryland’s commitments
under the Clean Water Act to reduce nutrient pollution in the Bay.
Gen. 3]                                                            5

If the U.S. Environmental Protection Agency (“EPA”) finds that
Maryland has broken its commitments, EPA could take certain
actions against Maryland, such as subjecting Maryland to increased
federal oversight and reducing the State’s federal funding. Thus,
as a practical matter, MDE might need to take enforcement action
to ensure that it can meet its obligations under the Clean Water Act.

                                I
                           Background

A.   The History of the Act: The Role of the 2010 Chesapeake
     Bay TMDL in its Enactment

      The General Assembly adopted the Act to address an
impending federal mandate that required Maryland and the six
other jurisdictions in the Chesapeake Bay watershed (the “Bay
jurisdictions”) to demonstrate, before December 30, 2012, how
each jurisdiction would reduce its nutrient discharges to the Bay.
2012 Md. Laws, ch. 149, Preamble. That mandate was the product
of the “2010 Chesapeake Bay Total Maximum Daily Load,” or
“Bay TMDL,” a Bay-wide planning document that EPA had issued
pursuant to the federal Clean Water Act and various consent
decrees. See generally Maryland Dep’t of the Env’t v. Anacostia
Riverkeeper, 447 Md. 88, 101-07 (2016). Although much of the
2012 Act is codified in the Land Use Article, it was enacted to
enable Maryland to meet the Clean Water Act requirements set by
EPA under the Bay TMDL, see 2012 Md. Laws, ch. 149, Preamble,
and therefore it must be read in the context of those requirements.

     1.   Applicable Clean Water Act Requirements

     The Clean Water Act seeks to ensure “fishable and
swimmable” waters. Shanty Town Assocs. Ltd. P’ship v. EPA, 843
F.2d 782, 784 (4th Cir. 1988). The federal statute implements that
goal primarily by regulating discharges from point sources, such as
pipes, through a permitting system that controls what the permit-
holder may discharge. See American Farm Bureau Fed’n v. United
States Envtl. Prot. Agency, 792 F.3d 281, 299-300 (3d Cir. 2015).
Point-source dischargers include wastewater treatment plants,
power plants, manufacturing and commercial entities, and
municipal stormwater systems. Point-source permitting, however,
does not address pollution caused by “nonpoint sources” that
discharge pollutants through seepage and run-off, instead of
through a pipe. Examples of nonpoint source discharges include
seepage from septic systems, run-off from stormwater that is not
6                                                    [104 Op. Att’y

collected into a stormwater management system, agricultural run-
off, and air pollution. When a body of water remains impaired by
a particular pollutant despite point-source regulation, the affected
State must also regulate nonpoint source discharges of that
pollutant. Specifically, the State must set a pollution “diet,”
expressed as a “total maximum daily load” (“TMDL”) for the
pollutant, and then decide how to allocate the required reductions
among various point-source and nonpoint source discharges.

     A State’s TMDL is subject to EPA’s approval. Failing that
approval, or failing the State’s submission of a proposed TMDL,
EPA itself must issue the TMDL. 33 U.S.C. § 1313(d)(2). Once a
TMDL has been set, the State must implement that TMDL through
a continuing planning process subject to EPA’s approval. 33
U.S.C. § 1313(e). The TMDL must, among other things,
demonstrate “reasonable assurance” that the jurisdiction can meet
the reductions in load and that the body of water can attain its
necessary water quality standard when those reductions are
achieved. Bay TMDL, ES-8; see also Farm Bureau, 792 F.3d at
291-92 (illustrating EPA’s use of “reasonable assurance[s]” in
adopting a TMDL). Although “it is up to the States to choose how
to implement [their] plans,” they “are often left with the difficult
choice of implementing the TMDL in accordance with EPA’s
suggestions, or face losing federal grants if they do not.” Food &
Water Watch v. United States Envtl. Prot. Agency, 5 F. Supp. 3d
62, 77 (D.D.C. 2013) (citing 33 U.S.C. § 1313(e)).1
        2. The Bay TMDL

     By 2012, the pollution of the Bay by nutrient discharges,
especially nitrogen discharges like sewage, had been known and
studied for decades.2 See, e.g., 2012 Md. Laws, ch. 149, Preamble.

    1
     The Clean Water Act also includes special provisions for the
Chesapeake Bay: The EPA Administrator, “in coordination with” the
signatories to the Chesapeake Bay Agreement, “shall ensure that
management plans are developed and implementation is begun . . . to
achieve and maintain . . . the nutrient goals of the Chesapeake Bay
Agreement for the quantity of nitrogen and phosphorus entering the
Chesapeake Bay and its watershed.” 33 U.S.C. § 1267(g). Maryland is
a signatory to the Chesapeake Bay Agreement and thus subject to those
requirements. See Chesapeake Bay Watershed Agreement (2014)
(Preamble; Affirmation).
    2
    See Chesapeake Bay Program Technical Studies: A Synthesis i-I,
United States Environmental Protection Agency (1982) (summarizing
Gen. 3]                                                                 7

Those nitrogen discharges from sewage can be reduced by
directing the sewage to an upgraded wastewater treatment plant,
which treats the sewage and then discharges it through a point
source regulated through the Clean Water Act’s permitting system.
Bay TMDL, 4-37. But on-site sewage disposal systems are not
“point sources,” so the seepage of nitrogen from those facilities into
the Bay is not regulated through the permitting system.

      Before the Bay TMDL, there was no comprehensive system
for reducing, tracking, and allocating nutrient discharges to the Bay
from nonpoint sources, including septics. Id., ES-3. EPA’s
issuance of the Bay TMDL in December 2010 filled that void by
putting the Bay jurisdictions on a diet to reduce their nitrogen,
phosphorus, and sediment discharges (known as pollutant “loads”)
from all pollution sources, including nonpoint sources like septic
systems. See Anacostia Riverkeeper, 447 Md. at 106-07. The Bay
TMDL allocates shares of the diet among the watershed states and
by major river basin. Bay TMDL, ES-5, ES-7. For all
jurisdictions, the Bay TMDL set a target of 2017 for achieving 60%
of the required reductions and a target of 2025 for 100% of the
reductions. The Bay jurisdictions, collectively, must reduce their
total nitrogen discharges by 25% by 2025. Id., ES-1; see also Farm
Bureau, 792 F.3d at 292 (describing the Bay TMDL). To achieve
that overall goal, the Bay TMDL requires Maryland to reduce
nitrogen discharges by 10.33 million pounds per year in order to
reach a target of 39.09 million pounds. See Maryland’s Phase I
Watershed Implementation Plan for the Chesapeake Bay Total
Maximum Daily Load ES-7 to ES-8 (Dec. 3, 2010) (“Phase I
WIP”).
      While preparing the Bay TMDL, EPA had determined
specific load limits for each pollutant and had required each
jurisdiction to create an initial Phase I “Watershed Implementation
Plan,” or “WIP,” to demonstrate the state’s methods for achieving
the required reductions. Id., ES-3, 5; see also Anacostia
Riverkeeper, 447 Md. at 109-10 (explaining the importance of
WIPs to the TMDL process). EPA also set deadlines for the
submission of Phase II WIPs, due in late 2011, and Phase III WIPs,

results of studies of nutrient pollution of the Bay). For a history of the
Bay jurisdictions’ joint efforts, over more than three decades, to address
the pollution of the Bay by nutrients, see, e.g, Rena Steinzor and Shana
Jones, Collaborating to Nowhere: The Imperative of Government
Accountability for Restoring the Chesapeake Bay, 4 Geo. Wash. J. of
Energy & Envtl. L. 51 (2013).
8                                                    [104 Op. Att’y

due in 2017. See Letter from William C. Early, Acting EPA
Regional Administrator to Hon. L. Preston Bryant, Chair,
Chesapeake Bay Programs’ Principals’ Staff Committee (Nov. 4,
2009) (“Expectations Letter”). In preparing their Phase I WIPs, the
watershed States were to allocate shares of the load limits for each
pollutant among various sectors identified by EPA. The point-
source sectors included wastewater treatment plants and industrial
facilities, and nonpoint sources were categorized into agricultural,
stormwater run-off, septic, and forest sectors. Bay TMDL, ES-8,
ES-9, 4-1, 4-5. Only after the State made allocations among those
sectors could the State model, monitor, and reduce each sector’s
discharges to keep the sector from exceeding its assigned share.
See, e.g., Phase I WIP, ES-2, ES-3, ES-6 (stating that the WIP’s
function is to “identify final target loads to be achieved by various
pollution source sectors” as part of the “accountability framework”
to “ensure the TMDL goals are reached in a reasonable
timeframe”); Anacostia Riverkeeper, 447 Md. at 107-08
(explaining the role of modeling in the implementation of the Bay
TMDL). In essence, discharges from the various sectors would
have to be reduced, and Maryland would have to decide how to
distribute the burden among the sources in each sector.

      The Bay jurisdictions would also have to demonstrate that
their plans would work in practice. Bay TMDL, 7-6. EPA
therefore required the jurisdictions to demonstrate “reasonable
assurance” that they could actually achieve the required pollution
reductions. Bay TMDL, 7-1; see also Anacostia Riverkeeper, 447
Md. at 109-10, 127-28 (emphasizing the importance of the
requirement that MDE provide “reasonable assurance” to EPA).
As part of that demonstration, each jurisdiction had to “describe
procedures for estimating additional loads due to growth” and to
plan for “additional pollutant load reductions that are at least
sufficient to offset the growth and development that is anticipated
in the watershed between 2011 and 2025.” Bay TMDL, 7-6. The
Bay jurisdictions were to submit their initial watershed
implementation plans in 2010. Then, in 2011, the jurisdictions
were to begin preparing their Phase II plans for submission. Id., 7-
7. EPA made clear that a jurisdiction’s failure to make satisfactory
progress or to adopt sufficient plans could result in any of
numerous “back-stop” actions by EPA, including a significant
Gen. 3]                                                              9

curtailment of the water-pollution powers that EPA had delegated
to the State and a loss of federal funding.3
      To comply with these requirements, therefore, Maryland
would need to demonstrate how it would reduce nitrogen
discharges from each sector of point-source and nonpoint-source
discharges. By 2010, Maryland had long regulated point sources
through its permitting system and had also regulated many
nonpoint source discharge sectors. However, Maryland had never
established an overall mechanism for managing discharges from
the septics sector.
      3.   The Failure of the First Septics Bill and the
           Development of the Tier Approach by the Task Force
           Created to Address the Impacts of Major Developments
           Served by Septics

     Maryland submitted the final draft of its Phase I WIP in
December 2010. The Phase I plans were only required to identify,
“to the extent that it [was] available,” the “specific actions and
controls that will be implemented by 2017.” Expectations Letter
(Enclosure B at 14). In its plan, Maryland projected that septics-
served households in the State would increase by 75,000 by 2020
and would result in increased nitrogen discharges of 1.4 million
pounds per year. Those increased nitrogen discharges from septics
thus would have to be offset by higher reductions in other uses.
Phase I WIP at 3-3 to 3-4. Later, Maryland would have to provide
information about how to achieve those offsets in its Phase II WIP.


  3
      EPA listed the following “back-stop” actions:
       [E]xpanding coverage of [point-source] permits to
       sources that are currently unregulated, increasing
       oversight of state-issued [point-source] permits, requiring
       additional pollution reductions from point sources such as
       wastewater treatment plants, increasing federal
       enforcement and compliance in the watershed,
       prohibiting new or expanded pollution discharges,
       redirecting EPA grants, and revising water quality
       standards to better protect local and downstream waters.

Id., ES-8; see also Letter from Acting EPA Regional Administrator
William C. Early to Hon. L. Preston Bryant, Chair, Chesapeake Bay
Programs’ Principals’ Staff Committee (Dec. 29, 2009) (“Consequences
Letter”).
10                                                   [104 Op. Att’y

MDE began preparing its Phase II WIP in 2011. That year,
legislation was introduced to “[l]imit[] the number of on-site
sewage disposal systems and improv[e] those systems,” with the
goal of “reducing the nitrogen load to the Chesapeake Bay,
focusing development within Priority Funding Areas, and
preserving agricultural and rural land and the character of those
areas.” H.B. 1107, 2011 Leg. Reg. Sess., Preamble. Although the
bill did not pass, then-Governor O’Malley appointed a 28-member
task force that included representatives from the Maryland Farm
Bureau, the Maryland Association of Counties, the Maryland
Municipal League, environmental organizations, and various
government agencies to reach consensus on legislation to achieve
those goals. Executive Order 01.01.2011.05. The task force was
also to address “the impact of major developments on septic
systems and their effects on nutrient pollution, land preservation,
agri-business, and smart growth.” Id.

      In its report, the task force acknowledged EPA’s
“accountability framework” and agreed on a “Comprehensive Plan
Tier Approach” under which “[l]ocal jurisdictions should designate
areas within . . . [their] comprehensive plan[s] into one of four
tiers” and then require “[w]astewater disposal methods, rural
preservation spending, and other criteria [to] vary by land use tier.”
Final Report of the Task Force on Sustainable Growth &
Wastewater Disposal 1, 5 (Dec. 2011). With little dissent, the task
force then outlined four tier classifications based on criteria such
as the availability of public water and sewer and the existence of
areas that were designated or planned for conservation. Id. at 5-7.
As is particularly relevant here, one goal was that major residential
developments would be directed toward areas planned for public
sewer service. Id. The task force submitted its report in December
2011. Meanwhile, Maryland had to prepare its Phase II WIP.

     4.   EPA’s Instructions for Maryland’s Phase II WIP:
          Describe How Maryland Will Either Avoid or Offset
          Any Growth in Nonpoint Source Discharges from
          Septics, Agriculture, and Development Sources

      In February 2012, EPA instructed Maryland further on what
it had to include in its Phase II WIP. See EPA Evaluation of
Maryland’s Trading and Offset Program, 3 (Feb. 17, 2012).
According to EPA, by the end of the year, Maryland had to show
more definitively how it would address any increased discharges
caused by growth in nonpoint source sectors, especially with regard
to “septics, agriculture and development.” Id. at 17-19. EPA gave
Maryland three choices: (1) develop a credible offset program for
Gen. 3]                                                           11

a sector that would require any growth in that sector to be offset by
reductions from the other sectors; (2) show “quantitatively” why
the sector was not growing; or (3) if the sector was growing, show
“quantitatively” why it was not contributing new or increased
loads. Id.
      Maryland thus faced the following situation at the outset of
the 2012 legislative session: Maryland had to reduce its nitrogen,
phosphorus, and sediment discharges to the Bay by 2025, and
during 2012, Maryland would have to demonstrate to EPA how
each nonpoint source sector would achieve those reductions.
Moreover, that year, in its Phase II WIP, Maryland would have to
show how it would achieve the reductions if any particular sector
grew. Even if no sector grew, Maryland would have to predict land
uses to determine the necessary reductions for each sector and to
track actual reductions for purposes of reporting on the attainment
of milestones. Noncompliance with the TMDL process could
result in loss of federal funding, loss of control over point-source
permitting, regulation of previously unregulated dischargers, and
other negative consequences.

B.   The Adoption of the Act in 2012: The Legislative Decision
     to Preserve Agricultural Uses by Limiting Residential
     Development on Septics to Certain “Tiers” of Land

      New septics legislation was introduced in 2012. The
legislation, which eventually passed and became the Act,
“embodie[d] the nearly unanimous recommendations of the Task
Force,” including the tier-mapping mechanism for allocating
growth among different land uses. See Md. Laws, ch. 149,
Preamble. In the Preamble, the General Assembly expressly
acknowledged Maryland’s obligations under the Bay TMDL. Id.
Explaining that federal law would require the State to give EPA a
detailed “Phase II” plan with “specific actions” for achieving the
required reductions in nitrogen discharges to the Bay, the General
Assembly recognized that the State had to ration the reductions
among various types of users. Id. The General Assembly also
found that development using septics, if allowed to continue at the
current rate and in the same way, would increase the load of
nitrogen added to the State’s waters. Id. That increase would
require Maryland to tighten restrictions on other nitrogen sources,
such as farms, wastewater treatment plants, and stormwater run-off
12                                                     [104 Op. Att’y

from existing urban uses, thereby “constraining economic growth
and placing additional burdens on the agricultural community.” Id.
     In an effort to avoid those negative results, and to enable
Maryland to provide “reasonable assurance” to EPA that the State
could meet its obligations under the Bay TMDL, the General
Assembly designed the Act in large part to account for, predict, and
place limits on major residential development, especially
development served by septic systems. The Act sought to achieve
those purposes primarily by establishing four land use tiers (i.e.,
Tiers I, II, III, and IV) and by prohibiting local jurisdictions from
authorizing major residential subdivisions, including major
subdivisions on septics, in certain tiers and under certain
circumstances.4 See LU § 1-508.

     Tier I applies to areas “served by public sewerage systems and
mapped [as] locally designated growth areas,” while Tier II
includes areas “planned to be served by public sewerage systems”
and designated for growth by the local jurisdiction. LU § 1-
508(a)(1)-(2). These two tiers are intended to reflect the areas
within the county where major growth is expected to occur and
where such development should therefore be served by public
sewer systems. Your questions pertain more to Tiers III and IV—
two lower-growth areas not planned to be served by public sewer.

      We start with Tier IV, the lowest growth area, because it is
somewhat easier to understand than Tier III. In essence, Tier IV
denotes areas that are not planned for public sewer service and that
are either dominated by agricultural lands, forested lands, and other
natural areas, or are designated in one of a number of ways for
preservation or conservation. See Maryland Dep’t of Planning,
Implementation Guidance for The Sustainable Growth and
Agricultural Preservation Act of 2012, at 10 (Aug. 1, 2012) (“MDP
Implementation Guide”). More specifically, Tier IV comprises:


     4
      There is no single, State-wide definition of major or minor
subdivisions under the Act. Instead, the Act contemplated that local
jurisdictions would adopt their own definitions of major and minor
subdivisions for purposes of the Act and also placed important
limitations on those local definitions. For a local definition adopted
before December 31, 2012, a “minor subdivision” may not exceed 7 new
lots. EN § 9-206(a)(6)(i)(1)(B). If a local jurisdiction did not adopt
definitions of major and minor subdivision applicable to the Act by
December 31, 2012, a “major subdivision” is “five or more new lots . . .
or other divisions of land,” and a “minor subdivision” is “fewer than”
that number. EN § 9-206(a)(5), (6).
Gen. 3]                                                           13

          (i) areas planned or zoned by a local
          jurisdiction for land, agricultural, or resource
          protection, preservation, or conservation;
          (ii) areas dominated by agricultural lands,
          forest lands, or other natural areas; or
          (iii) rural legacy areas, priority preservation
          areas, or areas subject to covenants,
          restrictions, conditions, or conservation
          easements for the benefit of, or held by a State
          agency, as defined in § 9-206 of the
          Environment Article, or a local jurisdiction
          for the purpose of conserving natural
          resources or agricultural land.

LU § 1-508(a)(4).

      Tier III includes other areas not planned for sewer service but
where the local jurisdiction is planning for growth or for “large lot
development.” MDP Implementation Guide at 10. Tier III also
includes municipal corporations and “existing Rural Villages and
towns” that are not served by public sewer. Id. In other words,
Tier III denotes areas that:

          (i) are not planned for sewerage service and
          not dominated by agricultural or forest land;
          (ii) are not planned or zoned by a local
          jurisdiction for land, agricultural, or resource
          protection, preservation, or conservation; and
          (iii) are one of the following:
          1. municipal corporations not served by a
          public sewerage system;
          2. rural villages as described in § 5-7B-03(f)
          of the State Finance and Procurement Article;
          3. mapped locally designated growth areas; or
          4. areas planned and zoned for large lot and
          rural development[.]

LU § 1-508(a)(3). With a few limited exceptions, Tier III areas are
generally the only areas under the Act in which major residential
development on septic systems is allowed to occur. See EN § 9-
14                                                         [104 Op. Att’y

206(g)(1) (explaining the type of sewage treatment method
permissible for residential subdivisions in each tier).5
      Although the Act does not expressly require a local
jurisdiction to adopt these tiers, see LU § 1-502 (providing that a
local jurisdiction “may adopt” tiers (emphasis added)), the Act
gives local jurisdictions a significant incentive to do so.
Specifically, a local jurisdiction cannot approve a “residential
major subdivision” other than one served by public sewer in a “Tier
I” area until the jurisdiction has adopted a map that classifies the
land within its borders “in accordance with” the tier-mapping
provisions in Title 1, Subtitle 5 of the Land Use Article. EN § 9-
206(f).6 Put another way, a local jurisdiction that has not adopted

     5
       In some cases, a specific geographic area may not “fit” neatly into
any of the tiers. MDP Implementation Guide at 12. For example, an
area might be served by public sewer but not within a designated growth
area (and thus not within Tier I as defined by the Act), such as when
public sewer is extended to a non-growth area to relieve that area’s
failing septic systems. See id. The Department of Planning has provided
recommendations to the local jurisdictions about how to best classify
those areas, using designations like Tier IA, IIA, IIIA, and IVA, but has
recognized that such areas might properly be placed in more than one
tier. Id.
     6
      Although this provision states that a local jurisdiction’s tier map
must be adopted “in accordance with § 5-104 of the Land Use Article,”
EN § 9-206(f) (emphasis added), that appears to be a drafting error.
Section 5-104 does not govern the adoption of a local jurisdiction’s tier
map, so that section cannot possibly be the provision to which the
General Assembly meant to refer. To the contrary, as originally enacted,
the statute cross-referenced a different provision in Article 66B of the
Maryland Code—a provision which is now codified as Title 1, Subtitle
5 of the Land Use Article. See 2012 Md. Laws, ch. 149 (providing that
local jurisdictions had to adopt their growth tiers “in accordance with
§ 1.05 of Article 66B”). While it is not entirely clear why the current
statute refers to § 5-104 instead of Title 1, Subtitle 5, it appears that the
error occurred as part of the process for transferring the provisions of
Article 66B into the new Land Use Article. As originally enacted, the
provisions of the Act governing the adoption of “growth tiers” were
codified in Article 66B, § 1.05. Later during the same legislative
session, the General Assembly reorganized Article 66B into the newly
created Land Use Article. See 2012 Md. Laws, ch. 426. When the
provisions that had been in § 1.05 of Article 66B were recodified as Title
1, Subtitle 5, see LU §§ 1-501 to 1-509, the Legislature did not update
the cross-reference in EN § 9-206(f), leaving the obsolete reference to
Article 66B. Our Office identified that problem, see Letter of Attorney
General Douglas F. Gansler to Governor Martin O’Malley (April 27,
Gen. 3]                                                                 15

growth tiers into its comprehensive plan “in accordance with” the
Land Use Article can only authorize minor residential subdivisions
on septics (as well as major or minor subdivisions served by public
sewer in a Tier I area). EN § 9-206(f)(2).7

      Separate requirements apply to jurisdictions that do adopt
tiers “in accordance with” the Land Use Article. Those
jurisdictions may approve major subdivisions in more areas, but
they still may only approve a residential subdivision in a “tier”
eligible for that use. See EN § 9-206(g). For example, residential
subdivisions in Tier I are not eligible for septic; they must be served
by public sewer. EN § 9-206(g)(1)(i). Similarly, in Tier II, only
minor residential subdivisions on septics may be approved; major
subdivisions must be served by public sewer. EN § 9-206(g)(1)(ii).
In Tier III, a local jurisdiction may approve a major subdivision
only if the local planning board has recommended approval after a
public hearing and a review of various factors, including “potential
environmental issues.” LU § 5-104. Finally, for Tier IV areas, a
local jurisdiction may not authorize a major subdivision, regardless
of the method of sewerage service, unless MDP has certified that
the project qualifies for an exception based on the density of the
developments in the jurisdiction. EN § 9-206(g)(1)(iii), (h).

C.       The Tier Mapping Process

      The Act also addressed the mechanics of tier-mapping. The
Act generally did not require counties to re-inventory the areas in
their respective jurisdictions. Instead, in an uncodified section, the
General Assembly stated its intent that the counties could do their


2012), and as part of the next year’s corrective bill, the Legislature
attempted to update the cross-reference. See 2013 Md. Laws, ch. 43.
However, in doing so, the General Assembly accidentally cross-
referenced the wrong provision, i.e., LU § 5-104, rather than Title 1,
Subtitle 5. (In fact, what is now LU § 1-504 had not even been located
in § 1.05 of Article 66B at all; it was codified in § 1.06 instead.) The
most likely explanation for that mistake is that the drafters copied an
existing cross-reference in a nearby subsection that had correctly referred
to LU § 5-104. See EN § 9-206(g)(1)(iv). In any event, whatever the
reason for the error, we read EN § 9-206(f) as requiring a local
jurisdiction’s tier maps to be adopted “in accordance with” Title 1,
Subtitle 5 of the Land Use Article. See also footnote 9, infra.
     7
      Under LU § 1-506, a county may choose not to adopt Tier II so
long as it documents its reasons for that choice.
16                                                    [104 Op. Att’y

tier-mapping from information already included in their
comprehensive plans and zoning ordinances:
             It is the intent of the General Assembly that
             local jurisdictions should use their existing
             comprehensive plan and zoning ordinance, if
             desired, to create the tiers as provided in
             Article 66B, § 1.05 of the Code and Title 1,
             Subtitle 5 of the Land Use Article, as enacted
             by this Act.

2012 Md. Laws, ch. 149 § 4(a). As explained by MDP, “[m]apping
the Growth Tiers . . . is intended to be a straight-forward exercise
based on existing local government plans and goals for growth and
land preservation,” such that “most of the Tier mapping will be a
reflection of existing zoning, comprehensive plans and sewer
service.” MDP Implementation Guide at 1. Accordingly, many of
the tier definitions are couched in the land-planning vocabulary that
local governments were already using in their zoning maps,
comprehensive plans, and other similar planning documents. For
example, areas to be mapped Tier IV include rural legacy areas and
priority preservation areas, LU § 1-508(a)(4)(iii), both of which are
defined by statute.8

      When preparing a tier map, a local jurisdiction “may submit
the [jurisdiction’s] proposed tiers and any relevant information to
[MDP] for . . . technical assistance, review, and comment.” LU
§ 1-503. After adopting growth tiers, the local jurisdiction must
provide to MDP “information necessary to demonstrate the precise
location of the tiers,” including, as necessary, maps and relevant
water and sewer plans. LU § 1-504. MDP then “may comment on
the growth tiers.” LU § 1-505. If MDP chooses to comment, the
local legislative body or planning board must “review the [adopted]
mapped growth tiers . . . in light of th[ose] comments” and “hold at
least one public hearing on the comments.” LU § 1-507(a)-(b).
Finally, the Act requires jurisdictions that adopt tiers to incorporate
them into their comprehensive plans. LU § 1-509.

D.       EPA’s Approval of Maryland’s Phase II WIP “In Reliance”
         on the Act

    As the General Assembly had intended, the State presented
the Act to EPA as evidence of “specific actions that, once
     8
     Md. Code Ann., Nat. Res. (“NR”) § 5-9A-02(i); Md. Code Ann.,
Agric. (“AG”) § 2-518; Md. Code Ann., State Fin. & Proc. (“SFP”) § 5-
408.
Gen. 3]                                                          17

implemented, will achieve the reductions necessary to meet the
nutrient and sediment limits by 2025.” See 2012 Md. Laws, ch.
149, Preamble; see also EPA Evaluation of Maryland’s Final Phase
I and 2012-2013 Milestones; Phase II WIP at 48, 81. EPA
approved Maryland’s Phase II Plan “in reliance” on Maryland’s
representations. Anacostia Riverkeeper, 447 Md. at 127-28. In
fact, in its evaluation of Maryland’s plan, EPA specifically stated
that “achievement of projected pollutant load reductions will be
supported by key state legislation passed in the 2012 session,”
including the Act. EPA Evaluation of Maryland’s Final Phase II
Watershed Implementation Plan, at 1 (May 30, 2012) (“EPA
Evaluation of Phase II WIP”); see also id. at 3 (noting that
Maryland had made three “[k]ey improvements since draft Phase
II WIP and final 2012-2013 milestone submission”). Specifically,
EPA noted that Maryland had enacted a “requirement, beginning
December 31, 2012, for local jurisdictions to adopt a four-tiered
system to guide growth on central sewer and septic systems, before
a jurisdiction may approve a major residential subdivision served
by onsite sewage disposal systems, community sewerage systems,
or shared systems.” Id. EPA then stated: “EPA will maintain
‘ongoing oversight’ for all sectors in Maryland to ensure that
commitments are implemented.” Id.

E.   Cecil County’s Growth Tiers

      Your letter explains that your questions were prompted by the
tier designations adopted by Cecil County. In December 2012,
Cecil County adopted growth tiers. MDP commented on those tiers
pursuant to LU § 1-505 and found that the tier designations
conflicted with the statutory criteria in multiple ways. See letter
from Richard Josephson, Director of Planning Services, MDP, to
Hon. Tari Moore, County Executive of Cecil County (Dec. 27,
2012). Among other things, MDP found that the county had not
classified priority preservation areas, rural legacy areas, or areas
planned or zoned for agricultural or resource protection as Tier IV
land, instead designating those areas as Tier III. Id. Those
designations, MDP explained, conflicted with the statutory criteria
providing that such areas are supposed to be in Tier IV. LU § 1-
508(a)(4)(iii). Cecil County held a public hearing on the
Department’s comments, as required under LU § 1-507, but did not
modify or amend its adopted tier designations. In December 2016,
the County incorporated its growth tier map into its comprehensive
plan.
18                                                   [104 Op. Att’y

                               II
                             Analysis
      You pose two questions about the Act. First, you ask whether
a local jurisdiction has the authority to approve a major residential
subdivision on septics if the local jurisdiction has adopted a tier
map that does not comply with the Act’s criteria. Second, you ask
whether the State is “compel[led]” to enforce a local jurisdiction’s
compliance with the Act. We will address each question in turn.
However, before doing so, we will set forth some general principles
about the respective powers of the State of Maryland and its
political subdivisions.

      Maryland’s counties and municipalities “are but local
divisions of the state.” Rockville v. Randolph, 267 Md. 56, 62
(1972). They therefore possess only the powers granted to them by
the State, either through the Maryland Constitution or enactments
of the General Assembly. See Kent Island Def. League, LLC v.
Queen Anne’s County Bd. of Elections, 145 Md. App. 684, 688-89
(2002). As a corollary to that principle, when a local jurisdiction
exercises a power delegated to it by the General Assembly, the
local jurisdiction’s power is “subject to the terms upon which it is
delegated.” Hewitt v. County Comm’rs of Baltimore County, 220
Md. 48, 63 (1959); see also West Montgomery County Citizens
Ass’n v. Maryland-Nat’l Capital Park & Planning Comm’n, 309
Md. 183, 198-99 (1987) (invalidating county’s exercise of power
“in any manner other than that specifically authorized” by the
enabling statute). Thus, a local enactment that exceeds the scope
of the delegation or that violates the conditions on that delegation
is invalid. See, e.g., West Montgomery County Citizens Ass’n, 309
Md. at 198-99.

      In the area of land use, the State has delegated various powers
to local jurisdictions, but those powers are subject to many State-
law requirements. See, e.g., LU §§ 3-101, 3-102 through 3-113
(requiring counties to adopt comprehensive plans with certain
plans and elements; requiring counties to specify how the plans will
protect certain uses); LU § 1-415 (requiring home-rule counties to
implement the statutorily required visions through their
comprehensive plans); see also LU § 1-203 (providing for
automatic repeal of commissioner-county ordinances to the extent
that they are inconsistent with Division I of the Land Use Article);
Maryland-Nat. Capital Park & Planning Comm’n v. Greater
Baden-Aquasco Citizens Ass’n, 412 Md. 73, 87-89 (2009)
(explaining that State law imposes limits on local governments’
land use powers); Mayor & Council of Rockville v. Rylyns Enters.,
Gen. 3]                                                             19

372 Md. 514, 574 n. 31, 575 (2001) (explaining that local
governments “wield only such [land use] powers as are granted to
them by the Legislature” and subject to the limitations imposed by
State law); cf. Md. Code Ann., Local Gov’t § 10-324(c) (providing
that the land use powers that the Express Powers Act grants to
charter and code home rule counties do not preempt the State’s
regulatory authority).

      In addition to the limits imposed by the Land Use Article,
local jurisdictions’ land-use powers are also circumscribed by the
State’s environmental laws. Particularly relevant here are the
State’s laws regarding the “waters of the State” and sewerage
systems, as set forth in Title 9 of the Environment Article. Under
those laws, the Secretary “[h]as supervision and control over the
sanitary and physical condition of the waters of this State to protect
public health and comfort,” and “[s]hall investigate . . . [a]ll points
of sewage discharge.” EN § 9-252(b)(1), (2); see also Department
of Env’t. v. Showell, 316 Md. 259, 269 (1989) (describing the
Secretary’s “broad powers to regulate sanitary facilities and
pollution control measures”). As explained below, MDE’s powers
in that regard include such matters as approving local water and
sewer plans and sewerage facilities, including septic systems. See
Part II.B, infra. Although the General Assembly has delegated to
local governments significant authority in the land use context, that
local authority does not override the State’s water and sewer
powers. Indeed, the Court of Appeals has expressly rejected the
proposition that “regulation of access to sewer service is purely a
matter for local control” or would “usurp[] . . . the power of local
governmental entities to control nonpoint source pollution and land
use.” Showell, 316 Md. at 272.

A.   Authority to Approve Major Residential Subdivisions Not
     Served by Public Sewer: May a Local Jurisdiction that
     Adopts a Noncompliant Tier Map Approve Those Projects?

      With those legal principles in mind, we turn to the Act, and,
specifically, § 9-206(f) of the Environment Article, to determine
whether a local jurisdiction may approve a major residential
subdivision on septics where the jurisdiction has adopted a tier map
that does not comply with the Act’s requirements. We begin with
the “normal, plain” meaning of the words in the statute and read
those words in context, keeping in mind the legislative purpose of
the enactment. Lockshin v. Semsker, 412 Md. 257, 275 (2010).
20                                                    [104 Op. Att’y

      Under the plain language of the statute, a local jurisdiction
“[m]ay not authorize a residential major subdivision served by on-
site sewage disposal systems, community sewerage systems, or
shared systems until the local jurisdiction adopts the growth tiers
in accordance with § 5-104 of the Land Use Article.” EN § 9-
206(f)(1). As explained in footnote 6, supra, the reference to § 5-
104 of the Land Use Article in EN § 9-206(f) appears to be a
drafting error, and the General Assembly instead meant to refer to
Title 1, Subtitle 5 of the Land Use Article, where the Act’s tier-
mapping requirements are actually codified. In any event, EN § 9-
206(f)(1) uses the term “growth tiers,” which are defined to mean
“the tiers adopted by a local jurisdiction in accordance with Title 1,
Subtitle 5 of the Land Use Article.” EN § 9-206(a)(3). Thus, a
local jurisdiction has not adopted “growth tiers” within the
meaning of the Act until it has adopted them “in accordance with
Title 1, Subtitle 5 of the Land Use Article,” EN § 9-206(a)(3), and
a local jurisdiction may not authorize a major subdivision on
septics (or any other major subdivision, except for one served by
public sewer in a Tier I area) until the jurisdiction adopts such
“growth tiers.” EN § 9-206(f)(1).9

      That means, at the very least, a local jurisdiction may not
approve a major residential subdivision served by septics if the
jurisdiction has declined to adopt a tier map at all. Such a
jurisdiction would instead be limited to approving minor
subdivisions served by septics or either major or minor
subdivisions served by public sewer in a Tier I area. See EN § 9-
206(f)(2). Your question, however, is whether the statute imposes
those same limits on a local jurisdiction that has adopted a map, but
where the map does not comply with the substantive criteria for
tier-mapping set forth in the Land Use Article. In our opinion, the
answer is generally “yes,” although that might depend, in some
cases, on the type and degree of noncompliance with the Act.

      Again, we begin with the words of the statute. As explained
above, EN § 9-206(f)(1) provides, in essence, that a local
jurisdiction’s authority to authorize a major subdivision on septics
is conditioned on that local jurisdiction’s adoption of growth tiers
“in accordance with” Title 1, Subtitle 5 of the Land Use Article.
To be “in accordance with” statutory provisions typically requires
one to comply with those provisions. See, e.g., Greater Baden-
Aquasco Citizens Ass’n, 412 Md. at 107-09 (finding that, when a
     9
      If there were any doubt about that, the Legislature also included
uncodified language in a related enactment confirming that local
jurisdictions must “comply with Title 1, Subtitle 5 of the Land Use
Article when adopting growth tiers.” 2013 Md. Laws, ch. 521, § 3(d).
Gen. 3]                                                                  21

master plan that governed a land use action had to be read “in
accordance with” a general plan provision, the land use authority
had to apply the general plan provision); Hewitt, 220 Md. at 63-64
(explaining that, under a statute requiring that zoning regulations
be “in accordance with” a locality’s comprehensive plan, a
“departure” from the comprehensive plan exceeded the locality’s
authority); Aberle v. Faribault Fire Dep’t Relief Ass’n, 230 Minn.
353, 360 (1950) (finding that the words “in accordance with” tend
to require “compliance”); see also Bryan A. Garner, A Dictionary
of Modern Legal Usage 14 (3d ed. 2011) (explaining that “to be in
accordance is to be in conformity or compliance”). Applying that
ordinary meaning here, given that a local jurisdiction’s growth tiers
must be adopted “in accordance with” Title 1, Subtitle 5 of the
Land Use Article, and given that those provisions establish the
criteria for mapping the tiers, see LU § 1-508, the plain language
of the statute suggests that a locality must adopt its tier map in
compliance with those criteria.10

     Thus, under EN § 9-206(f), it appears that the General
Assembly has prohibited a local jurisdiction from authorizing any
major subdivisions, except for those served by public sewer in a
Tier I area, until the locality has adopted growth tiers that comply
with the Act’s requirements. Put another way, the State has
conditioned a local jurisdiction’s authority to approve major
residential subdivisions served by septics on that local

   10
       Although in some cases the phrase “in accordance with” might be
read to mean “under” and thus perhaps not to require compliance, see,
e.g., Straus v. Foxworth, 231 U.S. 162, 169 (1913), we believe that
applying such an interpretation here would conflict with the Act’s
purposes. After all, the Act mandates that the “[t]he growth tiers adopted
by a local jurisdiction shall meet the . . . criteria,” LU § 1-508(a)
(emphasis added), and if local jurisdictions could simply ignore those
criteria in adopting their tiers, there would be no point in mandating the
criteria in the first place. Moreover, our interpretation finds support in
the Act’s legislative history. During floor debates on the Act, the bill’s
floor leader (and one of its sponsors) explained that the bill would require
local jurisdictions to adopt “growth tiers in accordance with specified
requirements,” suggesting that compliance with the Act’s requirements
themselves would be necessary, not just that the tiers had to be adopted
“under” the Act. Senate Proceedings No. 47 (March 20, 2012)
(statement of Sen. Pinsky) (emphasis added); see also 87 Opinions of the
Attorney General 106, 113 n.6 (2002) (“Statements of a legislator acting
as floor manager [or as] co-sponsor of the bill . . . while not conclusive
on legislative intent, are generally accorded some weight by the courts
in determining the meaning of a statute.”).
22                                                   [104 Op. Att’y

jurisdiction’s adoption of growth tiers, and has conditioned the
adoption of growth tiers on compliance with the criteria. Growth
tiers that do not comply with those criteria do not meet the
necessary conditions for a local jurisdiction to approve major
residential subdivisions outside of Tier I areas.
      We recognize there might be an argument that EN § 9-206(f)
merely prohibits a local jurisdiction from authorizing major
subdivisions on septics in those areas that have been mis-mapped,
and does not put the jurisdiction on the same footing as a
jurisdiction that has failed to adopt a tier map at all. However, the
statutory language does not support that distinction. Instead, the
statute provides that a local jurisdiction cannot approve major
subdivisions other than those served by public sewer in a Tier I area
unless and “until” the locality adopts, into its comprehensive plan,
growth tiers that are “in accordance with” the criteria in the Land
Use Article. A map that is not “in accordance with” those criteria,
by definition, cannot satisfy the condition that the Act places on a
local jurisdiction’s authority to approve most types of major
subdivisions, regardless of whether the subdivision will be built in
a compliant or noncompliant area. That interpretation also furthers
the core purposes of the Act, namely, to allocate the burden of
reducing nutrient pollution so as to preserve agricultural and other
existing uses and to enable the State to identify, in the State’s
upcoming WIP, detailed strategies for reducing that pollution. See
2012 Md. Laws, ch. 149, Preamble. A local jurisdiction’s adoption
of noncompliant tiers, even if a subdivision has not yet been
approved in a noncompliant area, could cast doubt on whether
Maryland has given the requisite “reasonable assurance” to EPA
that it can meet its obligations under the Bay TMDL.

      Nonetheless, there may be circumstances under which a local
jurisdiction’s mapping errors are so minor that the locality should
be deemed to have substantially complied with the Act’s criteria.
Substantial compliance is generally sufficient to satisfy a statutory
requirement when it “has fully attained the objective of the statute
as though there had been complete and literal compliance,” that is,
where “there has been such compliance with the essential
requirements of the statutory provision as may be sufficient for the
accomplishment of its purpose.” 64 Opinions of the Attorney
General 20, 24-25 (1979) (quoting Houman v. Mayor & Council of
Borough of Pompton Lakes, 155 N.J. Super. 129, 169-70 (Law.
Div. 1977)). Thus, substantial compliance might be achieved here
where mis-mapping does not prevent the tiers from serving the
Gen. 3]                                                                23

Act’s purposes.11 But, to be clear, it seems highly unlikely that a
local jurisdiction could substantially comply with the statute by
authorizing a subdivision in a mis-tiered area when the subdivision
would not be permitted if the area had been placed in the correct
tier.
      Whether a particular tier map meets the Act’s criteria in a
particular instance may also depend in part on the extent to which
the criteria allow flexibility as to how they may be implemented.
Some criteria do not give the local jurisdictions any flexibility as
to the tier in which particular areas should be located. One such
example is the criterion that requires priority preservation areas and
rural legacy areas, both of which are defined by State law and
certified by State agencies, to be mapped as Tier IV land.12 See LU
§ 1-508(a)(4)(iii). Other criteria do not seem to allow for much, if
any, leeway for a different reason; they rely on definitions that local
jurisdictions must apply under other laws when creating various
statutorily mandated plans. For example, areas that are “planned
to be served by public sewerage systems,” LU § 1-508(a)(2), are
designated by the jurisdiction’s water and sewer plans, see EN § 9-
505, while “areas planned or zoned . . . for land, agricultural, or
resource protection, preservation, or conservation,” LU § 1-
508(a)(4)(i), are presumably designated in the jurisdiction’s

  11
      Given that comprehensive plans are to be “comprehensive”—that
is, they are to be integrated and long-range planning documents as
distinct from piecemeal zoning—and given that tier mapping is to be
done in comprehensive plans, we are not suggesting that a local
jurisdiction could easily show that its map is in substantial compliance
despite the mis-mapping of a particular area. See, e.g., LU § 3-110 (plans
are to “serve as a guide for the development and economic and social
well-being of the local jurisdiction”); Coffey v. Maryland-Nat’l Capital
Park & Planning Comm’n, 293 Md. 24, 31 (1982) (cautioning that the
cumulative effect of not requiring subdivision plans to comport with
planning documents “can be illustrated by comparison to the putting of
water in a teacup drop by drop. After a period of time there comes the
drop which will cause the cup to overflow”).
  12
        A “Priority Preservation Area” is an area certified as such by the
Department of Agriculture and the Department of Planning based on
certain agricultural or forestry attributes. See AG § 2-518; SFP § 5-408.
A “Rural Legacy Area” is an area designated as such under the Rural
Legacy Program as an area “rich in a multiple of agricultural, forestry,
natural, and cultural resources.” NR § 5-9A-02(i).
24                                                      [104 Op. Att’y

comprehensive plans or zoning regulations.13 The Legislature’s
intent for those criteria, as explained in an uncodified section of the
Act, was apparently that local jurisdictions would use their other
plans to make their tier maps. See 2012 Md. Laws, ch. 149, § 4(a).

      However, the Act contains other criteria that seem to allow
local jurisdictions some interpretive leeway in implementing the
Act. For example, LU § 1-508(a)(3) requires the inclusion in Tier
III of areas not planned for sewer service that are “not dominated
by” either forest land or agricultural land. Because the phrase “not
dominated by” does not lend itself to any one specific meaning, this
criterion appears to allow local jurisdictions at least some
flexibility in determining which areas fit within that category and
thus at least some flexibility in mapping tiers that are “in
accordance with” that criterion. See MDP Implementation Guide
at 13 (explaining that “[t]here are a number of reasonable
approaches to delineating areas that . . . are dominated by
agricultural and forest lands or other natural areas” and
recommending a few potential approaches for how to apply that
criterion); see also id. at 12 (explaining that there are some
geographic areas that may not clearly “fit” within any particular
tier and that some of those areas “can be designated as any Tier on
the Tier map”).

     Still, the extent and nature of a local jurisdiction’s leeway
regarding even those generally worded criteria may be
circumscribed by two interrelated considerations. First, as noted
above, many of those criteria are couched in terms that the State or
local governments use in other contexts, so a local jurisdiction’s
departure from that usage solely for purposes of the Act might be
subject to challenge as an abuse of discretion.14 Second, we are to
     13
     See, e.g., LU §§ 3-201, 3-203 (addressing the preparation of
comprehensive plans), 4-202 (addressing zoning regulations “in
accordance with the plan”). Comprehensive plans must contain elements
and visions responsive to the State’s environmental and natural resource
laws. See LU §§ 3-102 through 3-113.
     14
      For example, jurisdictions with areas within the Chesapeake and
Atlantic Coastal Bays Critical Area might already have adopted an
approach for determining whether an area is “dominated by forest” or
agriculture. That is because regulations promulgated by the Critical
Areas Commission define “limited development” areas for purposes of
the State’s critical area laws, in part, based on whether the areas are
“dominated by agriculture, wetland, forest, barren land, surface water, or
open space.” COMAR 27.01.02.04; see also 73 Opinions of the Attorney
General 57, 62-63 (1988) (addressing the extent of local jurisdictions’
authority regarding the program criteria developed by the Commission).
Gen. 3]                                                            25

read the Act in light of its purposes. See, e.g., Merchant v. State,
448 Md. 75, 95 (2016) (explaining that a statute must be read
“within the context of the statutory scheme to which it belongs,
considering the purpose, aim, or policy of the Legislature in
enacting the statute” (citation and internal quotation marks
omitted)). The Act is a State-wide statute, with State-wide goals,
such that the effect of a local jurisdiction’s noncompliance is not
limited solely to the land within the jurisdiction’s borders. One
goal of the tier mechanism, as reflected in the Act’s Preamble, is to
enable Maryland to provide reasonable assurance to EPA that the
State can forecast, allocate, and reduce nonpoint source pollution
in the Bay. But that goal could be undermined if the Act were
construed to give each local jurisdiction unlimited discretion to
construe and apply the tier criteria in widely varying ways. In sum,
with limited exceptions, a local jurisdiction that has failed to map
its land “in accordance with” the tier-mapping criteria in Title 1,
Subtitle 5 of the Land Use Article will lack the authority to approve
major residential subdivisions on septics, because it will not have
met the conditions that State law places on that authority.

B.        Must the State “Enforce” the Tier Definitions?

      You also ask whether any law “compel[s]” the State to
“enforce” violations of the Act. We are not aware of any law that
compels the State to enforce the Act or its criteria in the sense of
requiring the State to bring an enforcement action against a local
jurisdiction for mis-mapping its land. However, that does not mean
that the State lacks any means to ensure compliance with the Act’s
requirements. Instead, in our view, there are at least two types of
mechanisms by which the State may be able to enforce the Act.15

       First, even before passage of the Act, MDE had authority over
certain aspects of the planning process for sewerage systems,
including septic systems. More specifically, MDE had the power
to approve county water and sewer plans, to sign off on final
subdivision plats for residential developments, and to approve
permits for the installation of individual sewerage systems. The
Act did not take away any of that authority. To the contrary, the
General Assembly sought to use existing “planning processes such
as . . . water and sewer plan[s], and subdivision plan approval” to

     15
      We do not mean to foreclose the possibility that there might be
other methods that are not discussed in this Opinion through which the
State could, in effect, enforce the Act.
26                                                   [104 Op. Att’y

accomplish its purpose of “[p]lanning for growth served by on-site
sewage disposal systems and shared systems.” 2012 Md. Laws, ch.
149, Preamble. In our opinion, when MDE, or its designee, is
performing the functions assigned to it as part of these processes,
the agency must at least consider a local jurisdiction’s compliance
with the Act and, in that sense, “enforce” it to some degree.

      Second, MDE has discretionary authority to enforce certain
provisions of the Environment Article, such as the provision in EN
§ 9-206(f) that prohibits a local jurisdiction from approving major
subdivisions other than those served by public sewer in a Tier I area
until the locality has adopted a tier map in accordance with the Act.
Although the statute does not expressly “compel” the State to take
enforcement action against a noncompliant local jurisdiction, MDE
may need to take action under certain circumstances to ensure that
the State complies with its own obligations under the Clean Water
Act to implement the Bay TMDL.

     1.   MDE Must Consider Compliance with the Act When
          Exercising its Authority Over Sewerage Matters

     The first way in which MDE can take steps to ensure
compliance with the Act is through its powers to review and
approve certain plans, plats, and permits that relate to sewerage.
Three such powers are relevant here. First, MDE is charged with
approving subdivision plats that developers must submit before
constructing residential subdivisions. See EN § 9-512(d); COMAR
26.04.03.02I; COMAR 26.04.03.02K. Second, MDE is charged
with approving applications for sewage disposal permits that lot
owners or developers must have before installing any sewerage
system, including septic systems. See EN §§ 9-204(h), 9-
252(b)(4); see also COMAR 26.04.02. Third, MDE is charged
with approving county water and sewer plans. See EN § 9-503.

          a.    MDE’s Approval of Subdivision Plats
      We first consider whether MDE can ensure compliance with
the Act through its authority to approve subdivision plats. MDE
has long had a role with respect to subdivision plats for residential
development. Although the principal power to approve subdivision
plats lies with each local jurisdiction’s planning commission (or
similar local entity), a person may not sell or build on land unless
a plat has been submitted to and approved by the Secretary of the
Environment or the Secretary’s designee. See EN §§ 9-206(j), 9-
512; see also COMAR 26.04.03.02I (“Lots may not be sold for
purposes of construction or construction begun in any subdivision
Gen. 3]                                                                   27

without the approval” of the Secretary or his designee); COMAR
26.04.03.02K (“A subdivision plat may not be recorded in the land
record offices of this State unless it bears the signature of the
Secretary or the Secretary’s designee.”). MDE typically delegates
this approval authority to the local health officer in each county,
but the ultimate authority over the process remains with MDE.16

      Under that scheme, MDE or its designee may not approve a
subdivision plat unless the proposed sewerage system conforms to
the applicable county’s water and sewer plan and will adequately
serve the development. EN § 9-512(d). Moreover, the Act added
a requirement that applies specifically to plats for proposed major
subdivisions in Tier III or Tier IV areas. EN § 9-206(j). Under that
new requirement, a platted lot for a major subdivision in a Tier III
or Tier IV area may not be developed or sold unless “there [has]
been submitted to [MDE] . . . [d]ocumentation by the local
jurisdiction that a major subdivision on-site sewage disposal
system, a community sewerage system, or a shared facility is in a:
(i) Tier III area as adopted by the local jurisdiction” or (ii) a Tier
IV area that is exempt from the general prohibition on major
residential subdivisions in such areas. EN § 9-206(j)(3).

      In our opinion, the Act’s addition of the “documentation”
requirement makes clear that the General Assembly intended MDE
to use its power over the subdivision approval process to enforce
certain aspects of the Act. Although the statute does not say
explicitly that lack of sufficient documentation under § 9-206(j)(3)
is a reason for MDE to deny approval of a subdivision plat, the
provision would make little sense if MDE could simply disregard

   16
      Local health officers, despite their name, are State officials, and the
Secretary’s designation of a county health officer to perform these
functions is the delegation of a State function. See Sugarloaf Citizens
Ass’n v. Frederick County Bd. of Appeals, 227 Md. App. 536, 549 (2016)
(“The decision of the local health officer on a septic system [proposed in
a site plan] is not a matter of county authority, but State-delegated
authority.”); see also id. (“[S]eptic system decisions are matters of state
law and regulations.” (emphasis in original)). For purposes of this
analysis, then, it does not matter whether the applications are reviewed
by MDE or the Secretary’s designee. In any event, county health officers
presumably lack the authority to take actions not permitted by State law.
See, e.g., Perdue Farms Inc. v. Hadder, 109 Md. App. 582, 590 (1996)
(“We believe that the [local] Board’s authority to impose the condition
complained of is preempted by state law, because the Board’s conditions
would prohibit [nitrogen] spraying in situations in which the State wants
to encourage it.”).
28                                                      [104 Op. Att’y

noncompliance with the requirement when reviewing plat
applications. After all, the General Assembly was aware of MDE’s
existing authority over subdivision plats, and presumably intended
the documentation provision to work in conjunction with that
authority. See 2012 Md. Laws, ch. 149, Preamble (explaining that
the Legislature intended to use “established planning processes” to
achieve the Act’s purposes). Indeed, the legislative history
confirms that the Legislature intended MDE to use the
documentation requirement to enforce the Act to at least some
degree. As explained by the sponsor of the floor amendments that
added the documentation provision, “MDE or MDE’s designee will
check on final subdivision plat approval that a major subdivision
on septics is in the correct growth tier,” and MDE “will not sign off
on final plats without that factual check.” Senate Proceedings No.
50, 2012 Leg., Reg. Sess. (March 23, 2012, Session No. 1)
(statement of Sen. Middleton); see also Hearing Before the House
Envtl. Affairs Comm. on S.B. 236, 2012 Leg., Reg. Sess. (April 4,
2012) (testimony of Joe Bryce, the Governor’s Chief Legislative
Officer) (“[T]here is a provision [in the bill] . . . that adds to
[MDE’s] existing authority in approving these developments to
allow [MDE] to make sure that the major subdivision that’s
submitted is in fact in the local jurisdiction’s Tier III area and not
in a Tier IV [area], and if it is not in a Tier III area then they would
have the ability to not approve [the subdivision] . . . .”).

      There remains a question, however, about the extent of
MDE’s power to enforce the Act through the subdivision approval
process. Unquestionably, under the documentation provision,
MDE or its designee may not approve a plat proposing a major
residential subdivision in a Tier III or Tier IV area that is ineligible
for the subdivision according to the local jurisdiction’s own tier
map. However, it is not as clear whether MDE must deny an
application for a subdivision in an area that the locality has mis-
mapped as Tier III instead of Tier IV—that is, when the project, on
its face, is in a tier that the local jurisdiction has mapped as eligible
for it, but the map violates the Act. Given that the statute requires
“documentation” that the proposed subdivision is in a “Tier III area
as adopted by the local jurisdiction,” EN § 9-206(j)(3) (emphasis
added), the statute could be read to authorize MDE only to examine
the locality’s tier map “as adopted,” and not consider whether the
area had been properly categorized as Tier III.
     But we must read the provision in light of the General
Assembly’s “purpose, the ends to be accomplished, [and] the evils
to be remedied by” the Act. Lockshin, 412 Md. at 274. Viewed
through that lens, the Act is best read to authorize MDE to decline
Gen. 3]                                                             29

to approve a plat for a major subdivision where the local
jurisdiction’s tier map conflicts with the Act’s criteria. The
Legislature’s purposes in adopting the tier mechanism were to help
predict growth in septics discharges, impose limits on development
using septics so as to preserve agriculture and protect the Bay, and
provide “reasonable assurance” to EPA that the State can fulfill its
obligations under the Bay TMDL. Given those purposes, we think
it unlikely the Legislature intended to immunize a local
jurisdiction’s blatant failure to comply with the Act’s tier-mapping
criteria from any meaningful State review or to allow a local
jurisdiction to undermine the State’s ability to achieve its goals
under the Clean Water Act. Instead, in our view, a local
jurisdiction that has mapped a Tier IV area as Tier III has not
validly “adopted” a tier map in the first place, see Part II.A, supra,
and we do not believe the General Assembly could have intended
such a tier map to suffice as sufficient “documentation” under EN
§ 9-206(j)(3) when the map violates State law and is therefore
invalid. See, e.g., Hewitt, 220 Md. at 63 (explaining that a local
power delegated by the Legislature is “subject to the terms upon
which it is delegated”); Worton Creek Marina, LLC v. Claggett,
381 Md. 499, 512 (2004) (voiding a local ordinance that was “not
in conformity” with State law); West Montgomery County Citizens
Ass’n, 309 Md. at 198-99 (invalidating county’s exercise of power
“in any manner other than that specifically authorized” by State
law). Thus, we conclude that the documentation provision permits
MDE, or its designee, to consider whether the locality has correctly
applied the Act’s tier-mapping criteria.17

      Our reading of the documentation provision is reinforced by
the interpretation that both MDP and MDE gave to the Act soon
after its passage. See, e.g., Baltimore Gas & Elec. Co. v. Pub. Serv.
Comm’n of Md., 305 Md. 145, 161 (1986) (explaining that the
contemporaneous interpretation of a statute soon after its

  17
       The General Assembly also did not alter MDE’s broad powers to
curb water pollution, to meet the nutrient pollution goals of the
Chesapeake Bay agreement, and to cooperate with other agencies. See,
e.g., EN §§ 9-302(b), 9-319. We read the documentation requirement in
the context of the statutory scheme of which MDE’s subdivision
approval and water pollution prevention duties are a part. See, e.g.,
Lockshin, 412 Md. 274-75. In light of that statutory scheme, the
documentation requirement should be read to allow MDE to meet its
obligations under the Clean Water Act. See Anacostia Riverkeeper, 447
Md. at 127-28 (explaining that EPA approved Maryland’s plans “in
reliance on” its representations (internal quotation marks and emphasis
omitted)).
30                                                   [104 Op. Att’y

enactment by an agency tasked with its implementation is entitled
to at least some weight in construing the statute). For example, the
Secretaries of both departments informed Cecil County in
September of 2013 that “appropriate steps to ensure compliance
with State law” would include, “if necessary, disapproval of major
subdivision plats in Tier 3 areas that do not comply with [the Act].”
Letter from MDE Secretary Robert M. Summers, Ph.D., and MDP
Secretary Richard Eberhardt Hall to Hon. Tari Moore, County
Executive, Cecil County (Sept. 13, 2013); see also Letter from Jay
Sakai, Director of MDE’s Water Mgmt. Admin., to Stephanie
Garrity, Health Officer, Cecil County Health Department (Jan.
2014) (stating that MDE “may withhold approval” of a subdivision
plat “if the proposed subdivision does not comply with . . . the
criteria set forth in Section 1-508 of the Land Use Article”).

      Although there is some evidence in the legislative history
suggesting that the documentation provision should not be read to
give MDE authority to assess the accuracy of a locality’s tier map,
that history is not conclusive. According to the legislative record,
the bill as introduced would have expressly prohibited MDE from
approving a plat for a major subdivision on septics in a Tier III area
unless MDE had “determined that the [locality’s] Tier III or Tier
IV growth tiers are consistent with” the Act’s tier-mapping criteria.
S.B. 236 (first reader, proposed EN § 9-206(b)(2)(iv)(2)).
Similarly, the bill was amended at one point to expressly provide
that MDE “may not approve a major residential subdivision” on
septics “until the local jurisdiction adopts the growth tiers in
accordance with” the Act, and to require local jurisdictions to
“certify” their growth tiers to MDP. Amendments to S.B. 236,
Senate Educ., Health, and Envtl. Affairs Comm. at 8 (March 23,
2012) (“Senate Committee Amendments”). However, in a later
floor amendment, the Senate: (1) deleted the provision that had
expressly required MDE to determine whether a locality’s Tier III
and IV areas complied with the Act; (2) amended the bill to prohibit
a local jurisdiction, rather than MDE, from approving major
residential subdivisions on septics until it adopted tiers; (3)
removed the requirement for local jurisdictions to “certify” their
tiers to MDP; and (4) added the documentation provision in EN
§ 9-206(j)(3). See Floor Amendments to S.B. 236 (March 23,
2012).

     In proposing those floor amendments, Senator Middleton
explained that they were a compromise brokered by Governor
O’Malley’s Administration in response to concerns raised by
counties, developers, farmers, and others. See Senate Proceedings
No. 50 (March 23, 2012, Session #1). In particular, the Maryland
Gen. 3]                                                             31

Association of Counties (“MACo”) had raised concerns that the
legislation, by explicitly tasking MDE with the approval of
residential subdivisions under the Act, would give MDE a new
“broad-based” power over all land-use decisions regarding those
subdivisions, even over things like “lot lines and street lines.”
Hearing on H.B. 445 Before the House Envtl. Matters Comm., 2012
Leg., Reg. Sess. (Feb. 15, 2012) (written testimony of MACo on
the bill cross-filed with S.B. 236). Although the original bill had
not expressly expanded MDE’s authority that far, Senator
Middleton explained that there were nonetheless concerns that
local land-use decisions would now be made by “a State agency”
that would not have “the accountability [to local property owners]
that a local board of elected officials do[es].” Senate Proceedings
No. 50 (March 23, 2012, Session No. 1). In response to those
concerns, he said, the amendments provided that “local
jurisdiction[s] will approve the subdivision plats . . . rather than
MDE” and that the “final authority in deciding whether a property
. . . should go in Tier III or Tier IV [will] lie[] with the county.”
Id.; see also Senate Proceedings No. 53 (March 27, 2012)
(statement of Sen. Pinsky) (stating that the floor amendments took
“approval” authority away from the State). Similarly, in responding
to a question about what the “remedy” might be if a county takes
an area that “clearly meets the criteria” for Tier IV but “put[s] it in
Tier III anyhow,” Senator Middleton stated that the county “would
be the ultimate decider of what is [in] Tier IV or Tier III.” Senate
Proceedings No. 50A (March 23, 2012, Session No. 2). That
testimony, along with the General Assembly’s decision to delete
the provision that had expressly required MDE to assess the
accuracy of a locality’s tier map, might suggest that the Legislature
did not intend MDE to check the accuracy of localities’ tier maps
during the subdivision approval process.

      However, at the same time the Legislature made those
changes, it also added the “documentation” provision in EN § 9-
206(j)(3). That change expressly preserved a role for MDE in
ensuring compliance with the Act, while clarifying that MDE
would not have any new, broad-based power over non-
environmentally-related matters like lot and street lines. In fact,
when addressing the documentation provision specifically, Senator
Middleton explained that it would serve as a “safeguard[] to ensure
that local jurisdictions follow the . . . framework for the adoption
of growth tiers.” Senate Proceedings No. 50 (March 23, 2012,
Session # 1) (statement of Sen. Middleton). In doing so, he
emphasized that, under the provision, “MDE w[ould] be able to
ensure at [the] final subdivision plat stage . . . that a local
32                                                    [104 Op. Att’y

jurisdiction’s approval of a major subdivision on septics is
accurate,” and that MDE will “make sure that it’s in the right tier
to prevent a county from saying . . . we think this ought to be in a
Tier IV [area] and take what belongs in a Tier III and move it over
to a Tier IV.” Id. Those statements, in contrast to some of the other
statements quoted above, suggest that the Legislature indeed
intended MDE to use the documentation provision to ensure that
local jurisdictions’ Tier III and Tier IV areas complied with the Act.
In short, the legislative history is not entirely clear as to the
intended effect of the amendments. We therefore hesitate to read
too much into the Legislature’s decision to delete a few draft
provisions as part of a sweeping compromise amendment,
especially when the same amendment added another provision that
seems to serve goals similar to some of the goals of the deleted
provisions.

      Rather, in our view, the best way to make sense of the
legislative history is that the floor amendments imposed certain
limits on MDE’s ability to review a locality’s tier map as part of
the subdivision approval process but did not deprive MDE of that
ability entirely. More specifically, under the bill as previously
drafted, MDE and MDP had to approve a local jurisdiction’s tier
map and would have had direct and total veto power over every
aspect of a local jurisdiction’s tier map. That is, local jurisdictions
would have to “certify” their tier maps to MDP, and MDE had to
submit the “initial” subdivision plat application under each local
jurisdiction’s new tier map to MDP for advice on whether the
locality’s growth tiers complied with the Act. Then, if the tiers did
not comply with the Act, MDE would have to refuse to approve the
plat. See S.B. 236 (first reader, proposed EN § 9-206(d)). Under
that version of the bill, therefore, MDP and MDE would have been
able to substitute their judgment for that of the local jurisdiction in
every situation, even when the definitions in the Act allow for
flexibility about how to apply the criteria to each local
jurisdiction’s specific situation.
      Under the Act as altered by the Senate floor amendments,
however, MDE and MDP do not have any direct veto power over
a local jurisdiction’s tier map. Although MDE still has authority,
as reflected in the documentation provision, to ensure that a local
jurisdiction does not authorize major subdivisions in areas where
the Act clearly forbids those types of subdivisions—such as in
priority preservation areas and rural legacy areas—the Act does not
permit MDE to second-guess a locality’s implementation of the
more generally worded criteria that allow for flexibility as to their
application. See Senate Proceedings No. 53 (March 27, 2012)
Gen. 3]                                                                 33

(statement of Sen. Pinsky) (explaining that the application of the
criteria for “dominated by” agricultural and forest land in particular
would be left to the counties to decide). That understanding of the
amendments gives meaning both to the Legislature’s decision to
delete certain provisions of the original bill and its decision to add
to the documentation provision in EN § 9-206(j).18 In other words,
the compromise struck by the O’Malley Administration appears to
have been that MDE and MDP lost the direct power to veto local
subdivision decisions (which had been of great concern to the local
jurisdictions), but MDE gained the more limited review authority
granted by the documentation provision. Thus, although the
legislative history raises questions about the extent of MDE’s
power to use the subdivision approval process to enforce the Act,
the General Assembly more likely intended that MDE (or its
designee) would have at least some power to reject plat
applications based on a local jurisdiction’s failure to comply with
the Act’s criteria.

      Given that you asked whether the State “must” enforce the
Act, the question then becomes the extent to which MDE is
required to examine the “documentation” submitted to it to
determine whether a local jurisdiction has complied with the Act.
Although MDE might not always have the expertise to determine
for itself whether the locality’s tier map complies with the Act, the
Department of Planning may comment on proposed tier maps prior
to their adoption. See LU §§ 1-505, 1-507. MDP thus might flag
for MDE the accuracy of a local jurisdiction’s tier-mapping.
Although we cannot generalize about the level of scrutiny that
MDE must apply to a locality’s “documentation” in every case, if
MDE is aware that a local jurisdiction may have violated the Act,
we think MDE or its designee must at least consider that factor in

  18
      Our understanding of the amendments could even be read as
consistent with Senator Middleton’s comments that local jurisdictions
would be the “ultimate decider[s]” about their maps, Senate Proceedings
No. 50A (March 23, 2012, Session #2), and that the tier maps might not
always be “what the State would like them to be at the end of the day,”
Senate Proceedings No. 50 (March 23, 2012, Session No. 1). In other
words, where the definitions in the Act give the localities leeway to make
choices about how to apply the tier-mapping criteria, the localities can
make those decisions, even if MDE and MDP might have preferred them
to apply those criteria differently. But the local jurisdictions cannot
ignore the criteria entirely where the Act does not leave them flexibility
about how to apply those criteria, at least if they wish to authorize major
residential subdivisions outside of Tier I areas.
34                                                       [104 Op. Att’y

reviewing the plat application. See, e.g., Anacostia Riverkeeper,
447 Md. at 121 (“‘We must be satisfied from the record that the
agency . . . examine[d] the relevant data and articulate[d] a
satisfactory explanation for its action[.]’” (quoting Natural Res.
Def. Council v. United States Envt’l Prot. Agency, 808 F.3d 556,
569 (2nd Cir. 2015)) (additional quotation marks and citation
omitted)); cf. Ergon-W. Virginia, Inc. v. United States Envtl. Prot.
Agency, 896 F.3d 600, 612 (4th Cir. 2018) (agency “may not turn
a blind eye to errors and omissions apparent on the face of the
[submissions]”).19

      In sum, when the documentation requirement is read in light
of the legislative purpose, we think that MDE (or its designee) may
enforce the Act’s criteria through the subdivision plat approval
process and may not simply disregard a local jurisdiction’s failure
to comply with the Act’s criteria. The level of scrutiny that MDE
must apply to the applicant’s “documentation” in a particular case
will turn on the facts of that case. However, given the ambiguity
in the statute and in the legislative history, the General Assembly
might wish to clarify the extent to which MDE must enforce the
Act through the subdivision approval process.

           b.      Sewerage disposal permits

      Regardless of whether the documentation provision added by
the Act allows MDE to consider the accuracy of a local
jurisdiction’s tier map as part of its subdivision approval process,
nothing in the Act or its legislative history indicates that the
General Assembly intended to diminish any of MDE’s existing
authority over sewerage matters. One of those powers that existed
before the Act is that, in addition to subdivision plat approval,
MDE must approve the installation of a developer’s sewage
disposal system before the developer may build a subdivision
served by septics. See EN § 9-252(b)(4); see also COMAR
26.04.02.03J (“The permits required by this regulation are in
addition to any approval to subdivide land pursuant to COMAR
26.04.03.”). As with subdivision plats, MDE typically delegates


     19
      We note that the burden of establishing the adequacy of
“documentation” in support of a subdivision plat application likely falls
on the applicant, as the party that is asking MDE or its designee to change
the status quo. See, e.g., Grasslands Plantation, Inc. v. Frizz-King
Enterprises, LLC, 410 Md. 191, 216-17 (2009) (explaining that the
subdivision applicant, as the party seeking to change the status quo by
developing the site, bore the burden of proof).
Gen. 3]                                                              35

this responsibility to county health officers, but the ultimate
regulatory authority belongs to MDE.
      Under MDE’s regulations governing this permitting process,
the Department or its designee “may issue a permit for an on-site
sewage disposal system” only “if it determines that the site and
proposed design can safely dispose of sewage and conform with
applicable laws and regulations.”            COMAR 26.04.02.03B
(emphasis added). In our view, the “applicable laws and
regulations” with which the proposed site for a septic system must
conform include the Act’s provisions prohibiting major
subdivisions on septics under certain circumstances, such as when
the local jurisdiction declines to adopt a tier map, its tier map was
not adopted “in accordance with” the Act, or the subdivision is not
located in a tier eligible for that use. In other words, a proposal to
develop a major residential subdivision on septics in an area that is
ineligible for that use under the Act would not “conform with
applicable laws and regulations.” Thus, under MDE’s regulations,
it appears that the agency must at least consider compliance with
the Act as part of the disposal-permit process and would have little,
if any, discretion to overlook a noncompliant tier map when
reviewing a permit application to build a septic system for a major
residential subdivision.

           c.   County Water and Sewer Plans

      We next examine the extent to which MDE may enforce the
Act’s requirements through its role in approving county water and
sewer plans. Under Maryland law, each county must adopt a water
and sewer plan, and each plan (or plan amendment) is subject to
MDE’s approval. EN § 9-503. Among other things, a plan must
project population growth, indicate the “quantity and quality of
waste to be discharged into the waters of this State,” “[d]escribe . . .
each area in the county where . . . [a]n individual sewerage system
may be installed,” and describe areas planned for multiuse or
community sewerage systems. EN § 9-505(a)(12)(iii), (13)(v-vi,
viii); see also Bethel World Outreach Church v. Montgomery
County, 184 Md. App. 572, 578 (2009) (explaining the process).
Further, as is particularly important here, each county’s water and
sewer plan must be “consistent with all county and local
comprehensive plans,” as well as “with the laws of this State that
relate to . . . water pollution, and land use[.]” EN § 9-505(a)(1),
(5); see also COMAR 26.03.01.02(A) (requiring that water and
36                                                     [104 Op. Att’y

sewer plans “develop . . . sewerage systems in a way consistent
with county comprehensive planning”).
      Because a county’s water and sewer plan must be consistent
with both the county’s comprehensive plan (which includes the
county’s tier map) and the State’s land use laws (which include the
Act’s tier-mapping requirements), the water and sewer plan must
necessarily comply with the requirements of the Act. Thus, MDE
may not approve a plan that conflicts either with the county’s tier
map or with the tier-mapping criteria in the Act. Of course, the
extent to which a particular water and sewer plan might conflict
with the Act will depend on the content of that particular plan, and
it is not possible to provide comprehensive guidance here about
every circumstance under which there might be a conflict. But, at
the very least, MDE should take steps to ensure that a county’s
water and sewer plan is consistent with the Act.

   The question again becomes the extent of MDE’s obligation to
examine whether a county’s plan complies with its tier map or
whether the tier map complies with the Act’s criteria. Recognizing
that MDE might not have the knowledge or expertise to evaluate a
county’s water and sewer plan for compliance with laws
administered by other agencies, the General Assembly included in
the statute a requirement that MDE seek input from those other
agencies. For instance, before approving a proposed water and
sewer plan or plan amendment, MDE must submit the plan to “the
Department of Planning for advice on the consistency of the
proposal with the local master plan and other appropriate matters.”
EN § 9-507(b). The advice MDE receives from MDP (and from
other agencies) may help to identify conflicts with the Act. In fact,
MDP will likely already have evaluated a local jurisdictions’ tier
mapping during the comment process under the Act. See LU §§ 1-
505, 1-507. Thus, if MDP has advised MDE that a county has
adopted mis-mapped tiers, and if those mis-mapped tiers call into
question the accuracy of the county’s proposed water and sewer
plan, we think that MDE must at least consider that fact when
reviewing the proposed plan. See, e.g., Anacostia Riverkeeper, 447
Md. at 121; cf. Ergon-W. Virginia, Inc., 896 F.3d at 612.20
     20
      Additionally, under MDE’s regulations governing the water-and-
sewer-plan process, “[c]onsideration shall be given to . . . all
governmental, industrial, and other plans for privately owned facilities
regarding water and sewerage at any level.” COMAR 26.03.01.02(A)(3);
see also EN § 9-510(b) (granting MDE broad authority to adopt
regulations to “carry out the provisions of [the subtitle pertaining to
water and sewer plans]”); Showell, 316 Md. at 270-71 (explaining that
Gen. 3]                                                                 37

       2. MDE’s Discretionary Enforcement Powers

      The second way in which the State may be able to ensure
compliance with the Act is through MDE’s discretionary authority
to enforce certain violations of the Environment Article. The
Department is authorized to use “the provisions of [EN] §§ 9-334
through 9-344 . . . to enforce violations of” Title 9, Subtitle 2 of the
Environment Article. EN § 9-268. Title 9, Subtitle 2 of the
Environment Article, in turn, includes EN § 9-206(f), which
generally prohibits a local jurisdiction from “authoriz[ing] a
residential major subdivision served by on-site sewage disposal
systems, community sewerage systems, or shared systems until the
local jurisdiction adopts the growth tiers in accordance with” Title
1, Subtitle 5 of the Land Use Article. See Part II.A, supra. Thus,
if a local jurisdiction approves a major residential subdivision—
other than a major subdivision served by public sewer in Tier I—
without adopting tiers that comply with the Act (or, for that matter,
if the local jurisdiction violates any other provision of EN § 9-206),
MDE may use EN §§ 9-334 through 9-344 to enforce EN § 9-206’s
requirements.

      Under EN §§ 9-334 through 9-344, the Department “shall
issue a written complaint if the Department has reasonable grounds
to believe that the person to whom the complaint is directed has
violated” either “(1) This subtitle; (2) Any rule or regulation
adopted under this subtitle; or (3) Any order or permit issued under
this subtitle.” EN § 9-334(a).21 Although that provision only

MDE’s duties with regard to water pollution require it to “cooperate with
agencies of other states and the federal government”). Thus, in
reviewing a proposed plan, MDE must give “consideration” to the Bay
TMDL and its own WIPs to determine whether the planned methods of
waste water disposal are consistent with its obligations under those plans.
Given that MDE has presented the tier designations to EPA as a method
of minimizing the adverse effects of septics on the Bay, and EPA has
approved the tier-based restrictions as a method of reducing discharges,
MDE might have to disapprove a water and sewer plan that conflicts with
the Act in order to comply with its promises under the Bay TMDL.
  21
      Even though EN § 9-334 provides that MDE “shall” issue a
complaint if MDE “has reasonable grounds to believe” that a violation
occurred, MDE is not required to find “reasonable grounds” for a
violation, and the agency is thus not required to issue an order or seek
injunctive relief. Instead, MDE’s enforcement power under EN §§ 9-
334 through 9-344 is discretionary. See e.g., Falls Rd. Cmty. Ass’n, Inc.
38                                                         [104 Op. Att’y

mentions violations of subtitle 3, those same rules apply to
violations of subtitle 2 by operation of EN § 9-268. After serving
a complaint, MDE may issue an order, which is final unless the
person served with the order requests a hearing. See EN §§ 9-335
to 338. Alternatively, MDE “may bring an action for injunctive
relief against any person who violates any provision of this subtitle
[or subtitle 2] or any rule, regulation, order, or permit adopted or
issued by [MDE] under this subtitle [or subtitle 2].” EN § 9-339;
see also EN § 9-268. The term “person” in those provisions
explicitly includes “any county, municipal corporation, or other
political subdivision of this State.” EN § 9-301. Thus, MDE may
take enforcement action against a county for authorizing a major
subdivision in violation of EN § 9-206.

      Although MDE is not required by the Environment Article to
use these provisions to enforce the Act’s requirements, the
Department might—depending on the severity of the violation—
need to take action to ensure that Maryland complies with its own
obligations under the Clean Water Act, the Chesapeake Bay Plan,
and the Bay TMDL. As explained above, Maryland must provide
EPA with “reasonable assurance” that Maryland can achieve the
load reductions assigned to it under the Bay TMDL. See Farm
Bureau, 792 F.3d at 291-92 (explaining the role of reasonable
assurances in TMDLs); see also Anacostia Riverkeeper, 447 Md.
at 109-10 (describing EPA’s “reasonable assurance” findings
regarding Maryland’s Phase I WIP). To do that, Maryland had to
demonstrate how it will offset any unplanned growth in a particular
sector by further reducing discharges from other sectors. See Phase
III Interim Letter. Maryland then expressly relied on the Act to
show EPA how it would satisfy that requirement. See EPA
Evaluation of Phase II WIP at 1, 3. A local jurisdiction’s disregard
of the requirements of the Act could cast doubt on whether
Maryland has given “reasonable assurance” that the State is
complying with the Bay TMDL. In turn, if EPA determines that
the State is out of compliance, EPA can take any number of “back-
stop actions” that could lead to a loss of federal funding and the

v. Baltimore County, 437 Md. 115, 142 (2014) (explaining that even
where a government agency is “charged generally with the responsibility
to enforce” certain requirements, it cannot possibly pursue enforcement
of every arguable violation. Rather, “[t]here are a myriad of
discretionary decisions made in determining how to employ limited
resources,” and “[i]t is well within the discretion of . . . officials to pick
and choose among the categories of violations, or to prioritize certain
types or areas of enforcement.”).
Gen. 3]                                                                 39

loss of State control over certain aspects of Clean Water Act
enforcement. See footnote 3, supra.22
                                 III
                              Conclusion

      In answer to your first question, a local jurisdiction that has
failed to adopt a tier map that complies with the criteria in the Act
is not authorized to approve major residential subdivisions other
than those served by public sewer and located in a Tier I area.
There may, however, be circumstances under which errors in a
local jurisdiction’s map are so minor that a court would deem the
map to substantially comply with the Act.

      Regarding your second question, the Act does not require the
State to bring a direct enforcement action against a local
jurisdiction to compel the locality to change its tier map. However,
MDE is at least required to consider compliance with the Act in
reviewing subdivision plat applications, sewerage disposal permits,
and water and sewer plans. In addition, MDE has discretionary
authority to bring an action to enforce EN § 9-206, including the
subsection prohibiting a local jurisdiction from authorizing certain
major residential subdivisions until it has adopted a tier map in
accordance with the Act. Although that enforcement power is
discretionary, a failure on Maryland’s part to implement the
measures that the State has promised to take under the Clean Water
Act could make the State vulnerable to “back-stop” measures
threatened by EPA, including a loss of federal funding and
increased federal oversight. The threat of those consequences may,
as a practical matter, compel the State to enforce its law. Still,
given that MDE’s enforcement obligations are not entirely clear,
  22
      Even if MDE chooses not to enforce the Act under EN §§ 9-334
through 9-344, a local jurisdiction that is out of compliance with the Act
may face the prospect of private suits by individuals or organizations that
object to the local jurisdiction’s approval of a major subdivision in
violation of the Act. Given the risks of both State and private
enforcement, one consequence of a local jurisdiction’s failure to comply
with the Act might be that potential developers of major subdivisions
will be reluctant to undertake such projects in local jurisdictions whose
authority to approve those projects is uncertain. See, e.g., Cleanwater
Linganore, Inc. v. Frederick County, 231 Md. App. 373, 392 (2016)
(“Where a developer assumed that its project could be thwarted by a last-
minute or mid-stream change to any of these non-zoning laws, it would
be less likely to undertake a substantial development at all in a
jurisdiction.”).
40                                            [104 Op. Att’y

the General Assembly may wish to clarify the State’s role in
enforcing the Act.
                               Brian E. Frosh
                               Attorney General of Maryland
                               Ann MacNeille
                               Assistant Attorney General

Patrick B. Hughes
Chief Counsel, Opinions and Advice
*Paul J. Cucuzzella, Assistant Attorney General, contributed
significantly to the preparation of this Opinion.
