Coastal NPS Program Management Area - Analysis
Coastal Nonpoint Source Pollution Control Program
Management Area - Land Cover Analysis
intent of the Section 6217 management area delineation is to ensure
adequate protection of the state's coastal waters. The geographic scope of the coastal nonpoint source pollution
control program must be sufficient to ensure implementation of
management measures to restore and protect coastal waters.
existing coastal zone boundary does not afford the level of
protection necessary to control sources of nonpoint pollution that,
individually or cumulatively, significantly impact the state's
coastal waters. A very
small percentage of the state's coastal drainage area is encompassed
by the existing coastal area/coastal boundary, which was established
as a zone of direct influence on coastal resources rather than
secondary, cumulative, or indirect impacts.
based on the following analysis, the management area originally
proposed by NOAA is, based upon scientific information, excessive
for purposes of controlling nonpoint sources of pollution in
Connecticut. A Section
6217 management area which encompasses substantial portions of the
northwestern and northeastern sections of the state may result in
ineffective program administration, requiring implementation of
management measures in areas of the state where land uses do not,
individually or cumulatively, impact coastal waters.
Connecticut proposes to include in its Section 6217 management area
additional land areas beyond the coastal boundary that have a
significant, measurable impact on coastal waters, thereby ensuring
more effective management of relevant land and water uses. Based on evaluation and agreements of the Long Island Sound
Study, a participant in the National Estuary Program, and best
available scientific understanding of the Long Island Sound
watershed and pollutant delivery system, the proposed management
zone will afford a level of protection in excess of Section 6217
requirements, while remaining politically achievable, credible, and
deciding the necessary extent of the management zone, the DEP
considered three critical factors: 1) land uses likely to contribute pollutants of concern to
Long Island Sound based on land cover; 2) proximity to the Sound of
those contributing land uses; and 3) existing condition of coastal
waters, including both areas of impaired uses and those that might
be threatened by future development or other pollutant-contributing
relationship between certain land covers (and land use activities)
and pollutant delivery is not controversial, although export co-efficients
vary widely depending on local conditions. The literature documents the correlation between increased
pollutant loads and increased human activity (Donigian, et al.,
1990; U.S. EPA, 1982; Frink, 1991; NYSDEC, 1992; Omernik, 1976;
McCreary et al., 1992). For
most pollutants, natural land cover exports the lowest load, and
urbanized land cover, the highest. Agriculture is a third broad category generally referred to,
and it generally exports pollutant loads higher than natural land
covers but lower than urban land covers. There is considerable overlap of export rate or co-efficient
ranges among the three categories and not all pollutants rank in
that order, but the general relationship holds true for most
relationship is largely attributable to the percent of impervious
cover associated with each land cover category. Natural covers have few impervious surfaces while
imperviousness increases with level of development. More impervious surface promotes increased runoff and
decreased pollutant capture from activities that occur on impervious
surfaces or from deposition on the impervious surfaces. Furthermore, both agriculture and development impact the
availability of natural vegetation that would normally buffer runoff
and pollutant delivery to surface and ground waters.
LISS has characterized this relationship between land use and
pollutant delivery in the development of its Comprehensive
Conservation and Management Plan (CCMP), which received final
approval on September 12, 1994 by the Governors of Connecticut and
New York and EPA Administrator Browner. For example, nitrogen has been identified by the LISS as the
pollutant most responsible for causing extensive hypoxic areas in
Long Island Sound during late summer. According to the LISS, urban land cover delivery of nitrogen
per unit area is at least three times as high, and may exceed five
times as high, as what runs off of forested lands. Agricultural runoff provides approximately twice as much
nitrogen as forests per unit area and may exceed three times as
much. Many other
pollutants have a similar relationship to urbanization because of
the increased level of impervious cover in urban environments.
a Geographic Information System (GIS) land use/land cover database
generated by researchers at the University of Connecticut (Civco et
al., 1992), urban land percentage in each town in Connecticut was
calculated. Urban land
is liberally defined to include seven land cover categories:
impervious surfaces, high density residential and commercial, medium
density residential, roof, pavement, turf and grass (which captures
large lawn areas of low-density neighborhoods), and major roads.
The LISS has defined more than 20% urban land cover as a
critical break point for nonpoint source management need. There are 64 of Connecticut's 169 towns with more than 20%
urban land cover (Figure 1). Forty-four
towns have more than 30% urban land cover (Figure 2).
Connecticut Towns with >20 Percent Urban Land Cover
2: Connecticut Towns with >30 Percent Urban Land Cover
towns with the highest percentage of urban land cover are
concentrated along the southwestern coastal area, in the Quinnipiac
River basin, and along the upper Connecticut River in the
Hartford-Springfield, MA corridor. Smaller urban areas include the Danbury area and the New
London-Groton area on the Thames River. These areas were identified for additional investigation in
developing the management area for the Section 6217 program.
Proximity to Long Island Sound
and modeling programs and studies show that pollutant loads
discharged or run off into riverine systems are subject to loss or
attenuation during transport (Donigian et al, 1990; Howarth et al.,
1991; Phillips, 1991). This
is especially true for non-conservative pollutants (e.g., BOD,
nitrogen, bacteria), which are subject to biological or chemical
conversion, but also holds true for more conservative pollutants.
Conservative pollutants may become buried in sediments,
deposited on floodplains during high flows, or be taken up into
plant or animal tissues. Also,
the form of a pollutant may change, rendering it biologically
unavailable, as, for example, when available ionic forms of metals
bind with sulfur, inorganic sediments, or organic matter (DiToro et
al., 1990). While these substances are not truly "lost" from
the system, many of the sinks effectively retain the pollutants to
the extent that they can be considered permanent, and are generally
not transported to coastal waters.
LISS has demonstrated the attenuation of nitrogen during transport
along the major tributaries that discharge to Long Island Sound (Frink
et al., 1993; LISS, 1994). For
example, the Connecticut River contributes nearly 14 million kg of
total nitrogen to the Sound each year (HydroQual, Inc., 1991).
The "natural" component of that load; that, is the
amount of nitrogen that the river is believed to have discharged
under precolonial conditions, is approximately 12.7 million
kg per year. By
difference, the anthropogenic load of nitrogen contributed to Long
Island Sound from sources in the entire Connecticut River Basin is
approximately 1.3 million kg each year. Of the documented human sources of nitrogen inputs throughout
the basin, 7.8 million kg of nitrogen per year are identified (this
amount is likely to be underestimated since point source
contributions were estimated throughout the basin and nonpoint
sources could be reasonably approximated only in Connecticut).
This means that only about 16% of the nitrogen contributed by
sources in the Connecticut River actually makes it to Long Island
Sound. The attenuation
loss estimated for the Connecticut River is similar to the 17%
export efficiency of nitrogen calculated by Jaworski (1992) for the Upper Potomac River Basin.
Interestingly, Jaworski et al. also reported an even lower
export efficiency for the conservative pollutant, phosphorus, of
only 8%. Clearly,
conservative pollutants can end up in long-term storage by burial,
sorption, or biological uptake.
smaller basins, less attenuation of pollutants is likely to occur
because transport times are less. The Quinnipiac River, for example, discharges 415 thousand kg
of nitrogen per year past the Wallingford gage, the lowest,
non-tidal monitoring station on the river. The natural load would be about 134 thousand kg per year,
leaving 281 thousand kg per year as the human contribution. An estimated 463 thousand kg of nitrogen per year are
contributed from sewage treatment plants and nonpoint runoff above
the Wallingford gage for a 40% attenuation during transport. Additional attenuation will occur between the Wallingford
gage and Long Island Sound, as well. The basin size-attenuation rate was briefly discussed by
Howarth et al. (1991) in relation to sediment transport. Sediment delivery ratios decrease as drainage area increases,
suggesting an increased opportunity for sediment storage as basin
size increases. The
nitrogen attenuation in the Connecticut River versus the Quinnipiac
River seems to support those estimates.
a similar data investigation of the Quinebaug River Watershed, a 37
percent attenuation rate between the monitoring stations at
Quinebaug and Jewett City occurred for phosphorous and a 12 percent
attenuation rate occurred for nitrogen. These rates of attenuation are consistent with Long Island
Sound Study information and support the proposed management area
decision for those towns on the Thames/Quinebaug River System.
these relationships between transport and attenuation, the LISS has
concluded that the most concentrated nonpoint contributions of
nitrogen to Long Island Sound originate from a very small land area
adjacent to the Sound. Excluding
New York City (because of uncertain drainage patterns) and the
atmospheric deposition of nitrogen directly on the Sound's surface,
the 13% of the total land area closest to the Sound in New York and
Connecticut contributes more than 40% of the anthropogenic nonpoint
nitrogen. In the Connecticut tributary basins, the 10% of the land
closest to the Sound contributes more than 30% of the anthropogenic
supporting the attenuation argument for both nitrogen and bacteria
is the Water Quality Standards Policy No. 21 for surface waters.
This policy states that domestic sewage treatment plants
south of Interstate 95 need to continuously disinfect all treated domestic sewage discharges year round to protect
the sanitary quality of shellfish resources. Yet, north of Interstate 95, this disinfection policy is
required only from May 1 to October 1, recognizing the need to
protect the sanitary quality of bathing waters. Essentially this long-standing policy supports the
attenuation argument for nitrogen and pathogens, recognizing that
direct coastal impacts are derived from land uses in near proximity
to those waters.
proposed Section 6217 management area includes 80 municipalities
representing about 62% of Connecticut's urban land use, which is a
high pollutant contributor in the state, while these towns represent
approximately 42% of the state's total land area. This means that management activity within the proposed
management area is much more efficient in terms of reducing
pollutant delivery to Long Island Sound than in more distant areas,
both because of the concentration of pollutant-contributing land use
and because of its proximity to Long Island Sound. In addition, urban areas not included in the Section 6217
management area should have considerable opportunity for pollutant
attenuation before reaching and during transport through the Section
6217 management area. This
reasoning is strengthened by monitoring data in the Connecticut
River that show attainment
of designated use goals in the lower part of the river that are not
supported immediately below the urbanized greater Springfield and
Existing Water Quality
final criterion for selecting the proposed Section 6217 management
area is existing water quality in need of either management or
protection. The LISS
has identified nitrogen and pathogen control as the two most
pressing water quality problems in need of management. Both of those problems involve non-conservative pollutants
for which management should focus on the near-coastal areas of most
relevance. For toxic
substances, pollutants that are contributed by nonpoint runoff, the
LISS did not identify additional management needs beyond existing
point source and stormwater programs (LISS, 1994).
The focus on geographic areas and
nitrogen/pathogen control is consistent with urban management
approaches published by the EPA for nonpoint source management (U.S.
EPA, 1990). As stated
in the forward of that publication, "In order for urban
jurisdictions to focus limited financial and technical resources in
an effective and efficient manner they must be able to relate
identified or suspected water quality problems to source areas in an
integrated approach." In
concordance with a similar philosophy of sensible, cost-efficient,
and effective management, the LISS chose to focus management
activity in areas that most directly affect Long Island Sound.
This same philosophy justifies a practical Section 6217
management area, as proposed herein, that will have a significant,
beneficial impact on water quality of Long Island Sound. Upon evaluation of this approach through monitoring, and as
supported in the Section 6217 approval guidance (NOAA and U.S. EPA,
1993), a process for identifying requirements for additional
management measures would be instituted, which might include
expansion of geographic areas where additional measures could be
In Connecticut's 1994 Section 305(b) water quality report, use
impairments are related either to point source problems or to local
nonpoint source problems, such as failing septic systems in coastal
areas, recreational vessel discharges, or urban runoff surrounding
local harbors and embayments. In no cases are sources from
distant, inland areas documented as causing use impairments in
coastal waters. The 1994 Section 305(b) report also has
identified hypoxia and nutrient runoff and pathogens as primary
coastal water quality problems in need of management (CTDEP, 1993).
To address those problems, the DEP is already implementing
commitments of the LISS CCMP, which do not call for priority actions
beyond a near coastal management zone that is considerably smaller
than the proposed Section 6217 management area.
Section 309 Analysis
Based on the above land cover/proximity/water quality criteria,
the majority of the state's southwestern urban centers are included
in the highest priority sub-basins identified by the LISS, and as
such have been identified as having the greatest potential to
contribute nonpoint source pollution to Long Island Sound. The
LISS did not include the sub-basins in southeastern Connecticut
within this highest priority area. Although proximal to Long
Island Sound, the southeastern-most sub-basins were excluded based
primarily on the fact that the percentages of existing urban and
agricultural land cover (uses) were not as significant in the
southeastern sub-basins as in the western watershed sub-basins of
Connecticut's Section 309 coastal boundary analysis found that
there is significant potential for future development within
southeastern Connecticut, as well as significant coastal resource
and water quality values in southeastern Connecticut which should be
protected from existing and future nonpoint source pollution.
These land use trends and water quality data have guided the
delineation of Connecticut's Section 6217 nonpoint source pollution
management area, clearly suggesting the incorporation of the
relatively undeveloped southeastern portion of the state in addition
to the heavily urbanized metropolitan areas adjacent to Long Island
Sound to focus Section 6217 implementation on localized nonpoint
source-related impacts from existing urban land uses and future
Accordingly, Connecticut's Section 6217 coastal nonpoint source
pollution management area will encompass the municipalities
comprising the first and second priority sub-basins identified by
the LISS and Section 309 Boundary Assessment project in order to
control the sources of nonpoint pollution that, individually or
cumulatively, may significantly impact the state's coastal waters.
Based on the technical analysis conducted for the LISS and the
Section 309 coastal boundary assessment, a Section 6217 coastal
nonpoint source management area which incorporates the
municipalities comprising the priority sub-basins extends inland to
the extent necessary to adequately control nonpoint sources of
Connecticut's Section 309 coastal boundary analysis identified a
substantial amount of urban land cover in the upper reaches of the
Connecticut River. However, these urbanized areas in the upper
reaches of the river were not assigned a high priority by the LISS
for pollutant management based on their distance from Long Island
Sound and the river's attenuation of nitrogen and bacteria. In
fact, the coastal waters of the lower Connecticut River at
Haddam/East Haddam are currently meeting their water quality goals,
in spite of the presence of highly urbanized areas along the upper
light of the substantial urban land cover in the upper reaches of
the river, especially in the Hartford metropolitan area, the
municipalities located immediately adjacent to the Connecticut River
will also be included in the management area as a precaution to
further ensure against nonpoint source pollution impacts to coastal
waters and provide for additional resource protection. While Connecticut is confident that the high priority
sub-basins in the lower portion of the state would be a sufficient
management area and adequately protect against coastal water quality
impacts, the inclusion of the municipalities located contiguous to
the Connecticut River in the Section 6217 management area will
provide an additional buffer to coastal waters in the river and
accommodate areas of urban development and population.
the inclusion of the municipalities contiguous to the Connecticut
River will allow for nonpoint source management of the river's
floodplain, as well as uninterrupted management of the entire river
as an integrated ecosystem, focusing coastal management-related
issues such as flood management and the protection of other
resources such as fisheries, wildlife, and freshwater tidal wetlands
throughout the Connecticut River corridor. Incorporation of the Connecticut River into the state's
Section 6217 management area will also correspond to OLISP's
regulatory authority in the Connecticut River for coastal, tidal,
and navigable waters pursuant to the Structures, Dredging, and Fill
Connecticut's Section 6217 coastal nonpoint source pollution
management area will be comprised of the following municipalities
(1990 populations included in parentheses; bold-faced type denotes
an existing coastal municipality):
Ansonia (18,403), Beacon Falls (5,083),
Bethany (4,608), Branford (27,603), Bridgeport (141,686), Cheshire
(25,684), Chester (3,417), Clinton (12,767), Cromwell (12,286),
Darien (18,196), Deep River (4,332), Derby (12,199), Durham (5,732),
East Haddam (6,676), East Hampton (10,428), East Hartford
(50,452), East Haven (26,144), East Lyme (15,340), Easton (6,303),
East Windsor (10,081), Enfield (45,532), Essex (5,904), Fairfield
(53,418), Glastonbury (27,901), Greenwich (58,441), Groton
Guilford (19,848), Haddam (6,769), Hamden (52,434), Hartford
(139,739), Killingworth (4,814), Ledyard (14,913), Lyme
(1,949), Madison (15,485), Meriden
(59,479), Middlefield (3,925), Middletown (42,762), Milford
(49,938), Monroe (16,896), Montville (16,673), Naugatuck (30,625),
New Canaan (17,864), New Haven (130,474), New London
Branford (12,996), North Haven (22,247), North Stonington (4,884),
Norwalk (78,331), Norwich (37,391), Old Lyme (6,535), Old Saybrook
(9,552), Orange (12,830), Oxford (8,685), Portland (8,418),
Preston (5,006), Prospect (7,775), Redding (7,927), Ridgefield (20,919),
Rocky Hill (16,554), Salem (3,310), Seymour (14,288), Shelton
(35,418), South Windsor (22,090), Stamford (108,056), Stonington
(16,919), Stratford (49,389), Suffield (11,427), Trumbull (32,016), Wallingford (40,822),
Westbrook (5,414), West Haven (54,021), Weston (8,648), Westport
(24,410), Wethersfield (25,651), Wilton (15,989), Windsor (27,817),
Windsor Locks (12,358), and Woodbridge (7,924).
to Section 6217 program development guidance, a state's management
area must extend inland to the extent necessary to control sources
of nonpoint pollution that, individually or cumulatively,
significantly impact coastal waters. The data provided above demonstrate that, from a land cover
and proximity perspective, urban land uses in Connecticut contribute
substantially more runoff than forested land and are more proximate
to coastal waters than agricultural uses; in some cases, urban land
uses are immediately adjacent to Long Island Sound and its major
tributaries. From a
water quality perspective, most of the water use impairments in Long
Island Sound and its tributaries are attributed to point sources or
localized nonpoint source impacts, not more distant, inland sources.
is unlikely that land use activities beyond Connecticuts Section
6217 management area will exert significant water quality impacts on
Connecticut's coastal waters because of the distribution of urban
development, the attenuation capacities of rivers, and the
improvements in best management practices and development planning
already in widespread use throughout the state.
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