19950786 Ver 1_WQ and Sewer Service Technical Memo_19950728

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BRUNSWICK COUNTY
REPLACEMENT OF BRIDGE NO. 198 ON SR 1172
OVER ATLANTIC INTRACOASTAL WATERWAY
AT SUNSET BEACH, NORTH CAROLINA
FEDERAL AID PROJECT NO. BRS-1813(1)
STATE PROJECT N0.8.2230101
TIP NO. B-682
WATER QUALITY
AND SEWER SERVICE
TECHNICAL MEMORANDUM
Prepared For:
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PLANNING & ENVIRONMENTAL BRANCH
NORTH CAROLINA DEPARTMENT OF TRANSPORTATION
II June 1995

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BRUNSWICK COUNTY
REPLACEMENT OF BRIDGE NO. 198 ON SR 1172
OVER~ATLANTIC INTRACOASTAL WATERWAY
AT SUNSET BEACH, NORTH CAROLINA
FEDERAL AID PROJECT NO. BRS-1813(1)
STATE PROJECT NO. 8.2230101
TIP NO. B-682

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WATER QUALITY AND SEWER SERVICE TECHNICAL MEMORANDUM
Prepared For:
Planning and Environmental Branch
North Carolina Department of Transportation
Prepared By:
Greiner, Inc.
Raleigh, North Carolina
June 7, 1995
Copyright ° 1995 Greiner, Inc.

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TABLE OF CONTENTS
Section Page
I. Introduction ........................................... 1
II. Project Description ....................................... 1
III. Setting and Location ...................................... 2
IV. Issues and Associated Assumptions ............................. 2
V. Existing Utilities ........................................ 3
VI. Planned and Proposed Utilities ................................ 3
VII. General Discussion and Background Information ..................... 4
VIII. Stormwater Management .................................... 6
IX. Conclusion ............................................ 7
References ............................................ 9
Attachments
Attachment A: Location Map
Attachment B: Project Area

' I. INTRODUCTION
' The purpose of this Memorandum is to assess and document the existing and planned
water and wastewater/sewer utilities for the Town of Sunset Beach and the surrounding
area. Also, those issues affecting water quality will be discussed. This discussion will _
take place within the framework of the proposed Sunset Beach bridge replacement
project.
However, it is not within the scope of this Memorandum to fully address those related
Natural Resource and Land Use issues and associated impacts, which will be examined in ,
greater detail and addressed in subsequent documents; including the Natural Systems
Technical Memorandum and the Draft Environmental Impact Statement (DEIS).
' II. PROJECT DESCRIPTION
' The Sunset Beach Bridge Replacement project study area is located in the extreme "
southeast portion of the state in Brunswick County (Attachment A). The general study
area includes an area that extends from the island, across the Atlantic Intracoastal
' Waterway, to NC 179 on the mainland in the Town of Sunset Beach (Attachment B).
The purpose of the proposed action is to replace a deficient and functionally obsolete
' bridge. This will improve highway access and safety between the island portion of the
Town of Sunset Beach and the Brunswick County mainland and will enhance watercraft
operation on the Intracoastal Waterway.
The existing bridge is a single-lane, steel-barge, swing-span draw bridge, with wooden
approach spans, and crosses the Atlantic Intracoastal Waterway at mile 337.9. The
bridge was constructed around 1953 by a private developer of the Sunset Beach area.
The beach road was added to the State System in 1960 as SR 1172, at which time the
bridge underwent substantial reconstruction. The North Carolina Department of
' Transportation (NCDOT) has maintained the bridge since it re-opened in 1961 through
a series of repairs and/or replacement of the structural wooden members. The bridge
was last inspected on March 10, 1992. The present condition is rated as poor, with an
' estimated remaining life of two years. The sufficiency rating is 4.0 on a scale of 0 to 100,
with 100 being perfect condition. It is designated as being both structurally deficient and
' functionally obsolete, and due to its poor condition, restrictive maximum load limits of
16 tons for single vehicles and 21 tons for truck and trailers have been imposed.
The existing bridge provides one-lane traffic operation using traffic signals at each end of
the bridge to control alternating directions of traffic flow. Between April 1 and October
31, draw openings for passage of pleasure watercraft are restricted to once an hour, on
' the hour, but is opened on demand for commercial vessels. During the shoulder months,
November 1 through March 31, the bridge is opened on demand for all vessels.
Both variable height bascule (draw bridge) and high-level, fixed-span designs are being
considered during project development. Existing location (center corridor) and

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relocation alternatives, both to the east and to the west, as well as a no-build alternatives
are being developed. Tunnel and ferry schemes are also being considered during the
initial corridor development phase of the study. Additionally, no-build alternatives,
including continual normal maintenance and the complete rehabilitation of the existing
structure will also be addressed during the DEIS phase of the project.
III. SETTING AND LOCATION
The Town of Sunset Beach, incorporated in 1963, is located in the extreme southeastern
portion of the state. A portion of the town is an island separated, from the mainland by
the Intracoastal Waterway. The island is approximately two miles long and one-half mile
wide. Existing land use on the island consists almost exclusively of residential structures.
Nearly all the developable land on the island has been subdivided into building lots.
There are 1,497 platted lots, of which some 60 percent are already developed (Hayes and
Associates, 1994a). Based on 1992 land use data (Hayes and Associates, 1993), there are
833 single family residences, 128 duplex units, 6 multifamily units, and 40 motel units.
The Town is a resort community and experiences wide fluctuations in population
according to the season, drawing most of its livelihood from tourism, primarily summer
rentals, golfing, marine recreation and fishing activities.
IV. ISSUES AND ASSOCIATED ASSUMPTIONS
One of the issues to be addressed in the Draft Environmental Impact Statement
concerns that of cumulative impacts driven by the increased growth and development
that could result from the bridge replacement project. It has been postulated that the
replacement of the existing bridge, thereby improving access, would foster and accelerate
development, some of which may be out of character or undesired. This same line of
reasoning has also been applied to the construction of a centralized wastewater treatment
system. This argument has been carried even further in suggesting that the bridge
replacement would also serve as an inducement to the construction of a wastewater
treatment system. Two issues have been raised in this regard: (1) because it is theorized
that the bridge will accelerate development, it is thought that the wastewater treatment
system will logically, and necessarily, follow; (2) it is also theorized that the construction
of ahigh-level, fixed span bridge would facilitate the implementation of the wastewater
treatment system by allowing a line between the mainland and the island to be attached
to the bridge.
While these are reasonable assumptions, recent studies indicate that bridge replacement
is a separate issue from the development of a centralized wastewater treatment system
and associated impacts to water quality. These associated impacts include stormwater
runoff.
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V. EXISTING UTILITIES
The water system currently supplying the Town of Sunset Beach and its extraterritorial
area (ETA) is owned and operated by Brunswick County. The Town actually buys its
treated water from the Brunswick County Water Service. The Town is responsible for
distribution of the water throughout its jurisdiction. All town residents are required to
be connected to the public water system and pay the minimum water usage fee. The
majority of the ETA residents are also connected to the system. The Town serves
approximately 1,300 customers within the corporate limits and 800 customers within the
extraterritorial limits (Hayes and Associates, 1993). The 1992 Sunset Beach Land Use
Plan states that the Brunswick County Water Service and the Town of Sunset Beach will
have sufficient capacity to accommodate the projected peak population through 1997. It
was estimated that the peak demand for Sunset Beach is only four percent of the
County's total capacity.
With respect to wastewater, the Town is served by ground absorption waste disposal
systems (individual septic tanks) that are approved and permitted by the Brunswick
County Health Department. This is a concern because of the lack of suitable soils for
these types of systems. There have also been documented septic tank system failures and
septic tank operational problems identified; both on the island and mainland areas within
Calabash and Sea Trail Plantation. Additionally, there are a number of building sites,
located both on the mainland and the island, for which the Brunswick County Health
Department will not issue septic tank permits. Lot inspections for septic tank permit
approvals are only conducted after an application for a building permit has been filed.
Therefore, the number of undeveloped lots which can not be permitted for septic tanks
can not be readily, quantified. It should be noted that sewage treatment package plants
can be constructed in areas that are not suitable for septic systems. Package plants may
not, however, be cost effective in all cases.
With respect to stormwater, the Town of Sunset Beach enforces those building code
regulations which pertain to stormwater control.
VI. PLANNED AND PROPOSED UTILITIES
As a result of concerns over the reliance on ground absorption systems, the development
and implementation of some sort of centralized wastewater treatment system has become
an important planning issue for the Town and the surrounding area.
There currently exist plans to construct a sewer system for the Sunset Beach-Calabash
' area, which will provide sewer and related services to a 45-square mile section of
Brunswick County. The proposed project is managed by the South Brunswick Water &
Sewer Authority which consists of representatives from the Towns of Sunset Beach and
' Calabash, along with Brunswick County. Sunset Beach voters endorsed a central sewer
system through a bond referendum which passed on April 5, 1994, approving a $5 million
dollar bond issue. However, the Town has no plans of issuing the $5 million in sewer
' bonds approved by voters, but instead was seeking a vote of commitment for or against

sewer. Anticipated funds include a $3.8 million loan from the North Carolina State
Revolving Loan Fund, a $5 million North Carolina Clean Water Bond Loan, and $26.1
' million in revenue bonds, which would be recouped through user fees.
Currently, the plan is for the Towns of Sunset Beach and Calabash to each undertake an
initial Phase I-A sewer program. The remainder of Phase I and Phase II could be
accomplished by the Towns individually or the Water and Sewer Authority. An initial
treatment facility with a capacity of around 2.5 million gallons per day (MGD) is
' envisioned. The effluent from the treatment facilities would be reused, primarily for golf
course irrigation. Amore detailed description of the proposed facility can be found in
The Financial Feasibility Report for Sanitary Sewer System Implementation Program
' Phases I and II (Powell Associates, 1993x).
There has been some conjecture regarding the necessity of attaching the sewer line to
.the bridge, creating the impression that sewer service could not be provided unless the
budge was constructed. However, this is not the case. On March 5, 1990, the Town of
Sunset Beach unanimously adopted a resolution urging that NCDOT engineers design
' the new bridge to allow for attachment of water and sewer lines. On March 26, 1990
NCDOT decided that it would not be feasible to attach water and sewer lines to the
structure. The Town therefore withdrew its request by resolution dated April 2, 1990
(Mullen et al vs. Skinner, 1990).
In addition, due to scheduling considerations in conjunction with deadlines for the sewer
loan applications versus the actual completion of a new bridge, it is not feasible to
consider attachment of the sewer line to the bridge. Therefore, this option was not
considered by the engineering consultant charged with developing the sewer program and
cost estimates for this option were not developed (J. Billups, P.E., 1994).
VII. GENERAL DISCUSSION AND BACKGROUND INFORMATION
The formal effort to develop a central sewer system came about in part as a result of a
Comprehensive Wastewater Study prepared for the Town of Sunset Beach (Powell
Associates Inc. & Piedmont Olson Hensley, 1992). This study identified the potential
' need for the provision of a central wastewater treatment facility based on the following
factors: (1) Public opinion, as documented in the 1986 and 1992 Land Use Plan Update
for the Town, (2) Documented septic tank system failures throughout the Planning Area
' (the Towns of Sunset Beach and Calabash, their Extraterritorial Jurisdictional
boundaries, and likely adjacent areas of growth) and septic tank operational problems
identified primarily on the island and within the Sea Trail Plantation Community, (3)
' Potential for environmental enhancement of sensitive adjacent shellfish waters through
elimination of both septic tank and surface water runoff pollution sources, (4) Increased
reliance throughout the Planning Area on alternative sewer systems for individual lots,
' (5) Requests for sewer service by individual and multiple lot owners for which lots the
Brunswick County Health Department has denied septic tank permits.

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This study further concluded that: (1) There is a present environmental hazard associated
with failing septic systems, (2) There is a present environmental hazard associated with
' the lack of an effective stormwater management program, (3) There is a present
environmental hazard associated with pollution from nutrients applied to golf courses for
fertilization purposes being allowed to flow directly into adjacent streams and other
' water courses, (4) Existing state regulations governing the installation of on-site sewer
systems may not afford adequate protection of ground water and surface water quality,
(5) Surficial water supply aquifers are diminishing in terms of both quantity and quality,
' (6) Septic tank systems, particularly on the island of Sunset Beach, are being used at flow
rates far in excess of their design capacities, (7) Building sites exist for which the
Brunswick County Health Department will not issue septic tank permits.
' Powell Associates has conducted ev
s eral studies of the area and concluded that septic
tank systems were having an adverse impact on both groundwater and estuarine water
quality on and around the island of Sunset Beach. This was reflected by increased levels
of fecal coliform and other constituents of wastewater (Powell Associates, 1993b).
' There are basically three factors that contribute to groundwater and estuarine water
quality. The first involves high groundwater table conditions, such as those that exist on
the island. The effluent may not have time to be "treated" before coming into contact
with the groundwater. A 1989 study prepared for the North Carolina Division of Coastal
Management by Thomas P. Augspurger entitled "Assessment of Coastal North Carolina
' Domestic Wastewater Disposal Alternatives" states "that a preponderance of evidence
suggests that the 30 centimeter separation (current state minimum) between septic drain
line bottoms and the seasonally high water table does not ensure adequate aerobic
conditions to properly treat domestic wastewater" (Powell Associates, 1993b).
The second factor is the nature of the soils. Excessively permeable coarse grained soils,
' such as those found on the island, are not effective in the removal of viruses from septic
tank effluent.
Finally, there is the population density factor. The North Carolina Division of
Environmental Management recognizes the potential adverse impact of using septic tank
systems in higher density areas (greater than 1,200 gallons of waste per acre, or greater
' than three residential units per acre) in the coastal region (Powell Associates, 1993b).
This problem is prevalent on the island where lots are typically 5,000 square feet,
resulting in a density of 8 units per acre. (It should be noted that the island portion of
' the Town of Sunset Beach includes two types of zoning: BR1 -oceanfront lots with a
minimum size of 7,500 square feet; and BR2 -all other lots with a minimum size of
4,500 square feet. The island also has lots that were platted prior to when the zoning
' regulations went into effect.)
' There has been considerable discussion with regard to the provision of centralized sewer
service fostering unwanted or uncontrolled development. While it is certainly true that
sewer availability is a factor in augmenting growth, it is not the determining factor.
' Market forces exist outside the availability of sewer service. It is "likely that
development will continue in Sunset Beach with or without a sewer system as long as
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there is a demand for resort housing. If a centralized sewer system is not built,
developers will find other ways to build on large tracts of land without septic tanks. For
' example, developers could build private package treatment plants as was done in the
Colony multi-family development in Sunset Beach." (Hayes and Associates, 1994x)
' The control of development is better handled by formal guidance system mechanisms as
opposed to restricting services which may be beneficial to the environment and human
health. The Town of Sunset Beach utilizes several land use planning tools to manage
' and direct its growth. These include zoning and subdivision ordinances, capital
improvement policies, and a Land Use Plan. There is also a permit program,
administered by both the State and the Town, which regulates development in Areas of
Environmental Concern.
It is important to note that these factors, conditions, and conclusions were derived
independently of the issue of the bridge and highlight the need for a centralized
wastewater treatment system, regardless of the outcome of the proposed Sunset Beach
' bridge replacement project.
VIII. STORMWATER MANAGEMENT
' A separate but related issue are those impacts to water quality associated with
stormwater runoff. There is some debate as to which is a greater threat to water quality,
the continued reliance on septic systems or uncontrolled runoff from development. In
the 1992 Land Use Plan Update, stormwater runoff was identified as a major concern.
One of several policy statements which were developed reads as follows; "The Town of
Sunset Beach encourages the use of innovative systems which encourage the use of
pervious or semipervious materials and the retention of natural- vegetation which
functions as a filter which minimizes the rapid release of pollutants to coastal waters
' through stormwater runoff." Consequently, the Town of Sunset Beach supports the
concept of a regional stormwater management plan.
' Discussions regarding the development of a centralized wastewater treatment system
have also included the development of a comprehensive stormwater management
program. The Comprehensive Wastewater Study report (Powell Associates & Piedmont
' Olson Hensley, 1992) also called for the preparation and implementation of a Master
Stormwater Management Plan to minimize the pollution potential from future
development activities, and to remediate existing pollution problems associated with
' stormwater runoff.
Several elements have been identified which would comprise such a plan. These include
the requirement of on-site retention and/or the treatment of stormwater from all new
development. This would be implemented regardless of size, from single family homes
' to large scale development. A second element would require the .elimination or
treatment of existing sources of runoff pollution. This would include paved areas which
allow petroleum products to concentrate and runoff into adjacent waters as well as
nutrients from fertilizers and pesticides.

Currently, there is consideration of a Basin-Wide Stormwater Management Study for the
communities in South Brunswick County, including the Town of Sunset Beach (Powell
' Associates, 1993c).
Within the vicinity of Sunset Beach, the waters of the Intracoastal Waterway and
Calabash Creek are designated as Primary Nursery Areas by the North Carolina Marine
Fisheries Commission. These are waters which correspond to the SA classification as
defined by the North Carolina Department of Environment, Health, and Natural
' Resources as "tidal salt water used for shellfishing, primary recreation, aquatic life
propagation and survival, fishing, wildlife, and secondary recreation." However, these
waters have been currently closed to shellfish harvesting by the North Carolina Division
of Marine Fisheries.
Again, these conditions exist now and further study is warranted irrespective of the
bridge replacement. This is especially true on the mainland, where growth has been
significant during the past ten years.
' With respect to the bridge replacement, all of the current alternatives will result in short
term impacts to water quality. Construction of the structure within the limits of open
water will likely result in some impacts associated with dredging, pile driving or other
forms of excavation connected to bridge construction. Any type of dredging or
disruption of the substrate will likely cause temporary increases in turbidity. This could
result in potential decreases in dissolved oxygen levels in the immediate area of
construction activity.
' Direct impacts from runoff from the bridge may also occur. This can be mitigated
during design and construction through collection of Stormwater runoff into approved
water quality settlement systems. Various types of Stormwater collection and treatment
' systems will be investigated to determine the most economical alternative that meets
NCDEHNR stormwater quality certification requirements.
' Long term impacts are expected to be minimal. All of the current alternatives are
associated with the regular dredging of the Intracoastal Waterway for vessel traffic.
Stringent application of best management practices (BMP's) and other sedimentation
' control measures must be implemented adjacent to coastal waters.
' IX. CONCLUSION
Several studies have now been completed regarding various impacts that will result from
' the bridge replacement project.
In a economic study prepared by Apogee Research, Inc., the conclusion was reached that
' the primary driving forces for mainland development are essentially independent of the
ease or difficulty of access to Sunset Beach Island (Apogee, 1994).

An analysis of the impacts of bridge replacements for Holden Beach and Ocean Isle
Beach, prepared by Hayes and Associates, concluded that the type of bridge access did
' not greatly influence the rate or character of development on the islands (Hayes and
Associates, 1994b). Therefore, it is reasonable to assume that a bridge replacement will
not necessarily be the driving factor for rate or type of development with respect to
Sunset Beach. Other factors that may influence the development of the Sunset Beach
island include availability of sewer service, zoning, land use and regulations imposed by
CAMA.
It can be stated with a reasonable de ree of confidence that those issues concernin
g g
water quality and wastewater needs, associated with Sunset Beach and the surrounding
area, are independent of the type of access provided to Sunset Beach.

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' REFERENCES
1 Apogee Research, Inc., 1994. Economic Impact Analysis. Prepared for the North
Carolina Department of Transportation.
Billups, J., 1994. Personal communication.
' Hayes and Associates, 1994x. Phase I Land Use Impact Report. Prepared for the North
Carolina Department of Transportation.
Hayes and Associates, 1993. Town of Sunset Beach, Land Use Plan Update 1992.
Hayes and Associates, 1994b. The Induced Impact on Land Use as The Result of High
Rise Bridge Replacement at Holden Beach and Ocean Isle Beach, NC. Prepared for
the North Carolina Department of Transportation.
' Hayes and Associates, 1994c. Phase I Social Impact Report. Prepared for the North
Carolina Department of Transportation.
' Mullen et al vs. Skinner, 1990. Memorandum Opinion, U.S. District Court, Eastern
District of North Carolina, No. 90-547-CIV-S-BR, November 19, 1990.
' North Carolina Department of Transportation, 1992. Sunset Beach Bridge Replacement
Study Scoping Report/Comments Secmmary Working Paper.
' Powell Associates of NMB, Inc. & Piedmont Olsen Hensley, 1992. Comprehensive
Wastewater Study, Town of Sunset Beach.
' Powell Associates of NMB, Inc., 1993x. Soccth Brunswick Water & Sewer Authority and
Town of Calabash & Sicnset Beach Financial Feasibility Report for Sanitary Sewer
System Implementation Program (Phases I & II).
Powell Associates of NMB, Inc., 1993b. Demonstration of Impact or Non-Impact of Septic
Tanks on Groundwater and Surface Water Quality on and Around the Island of
Sunset Beach.
' Powell Associates of NMB, Inc., 1993c. Outline Of Proposed South Brunswick
Environmental Management Program.

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PROJECT: 8.2230101 B-682
BRUNSWICK CO.
REPLACEMENT OF BRIDGE OVER
INTRACOASTAL WATERWAY ON
SR 1172 AT SUNSET BEACH
ATTACHMENT A

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