SEPA
United States
Environmental Protection
Agency
Region 4
345 Courtland Street, NE
Atlanta, GA 30365
EPA 904/9-81-091
May 1982
Environmental
Impact Statement
Hilton Head, South Carolina
Wastewater Facilities
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DRAFT
ENVIRONMENTAL IMPACT STATEMENT
for
HILTON HEAD ISLAND, SOUTH CAROLINA
Prepared by
U.S. Environmental Protection Agency
Region IV
Atlanta, Georgia 30365
This Draft EIS addresses proposed wastewater facilities for
Hilton Head Island, South Carolina. Numerous wastewater
management alternatives have been evaluated with particular
attention to water quality in the area's surface and
groundwater resources and the impacts of projected population
growth on the natural and human resources of Hilton Head Island
and the surrounding area.
The comment period for the Draft EIS will remain open until May
12, 1982. Comments and inquiries should be forwarded to:
John E. Hagan III, P.E.
Acting Chief, Environmental Assessment Branch
EPA, Region IV
345 Courtland Street, N.E.
Atlanta, Georgia 30365
404-881-7458
Approved by
'TT&Sr^i £*i?L>
CTrTarleaf R. Jete^^ Date
Regional Administrator
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EXECUTIVE SUMMARY FOR ENVIRONMENTAL IMPACT STATEMENT
HILTON HEAD ISLAND WASTEWATER FACILITIES
Draft ( x )
Final ( )
Environmental Protection Agency
Region IV
345 Courtland Street
Atlanta, Georgia 30365
Type of Action:
Administrative Action ( x )
Legislative Action ( )
EXECUTIVE SUMMARY
PART A. EXISTING PROBLEM
This Environmental Impact Statement (EIS) addresses alternatives for and
impacts of the provision of wastewater management facilities on Hilton Head
Island. Wastewater collection and treatment on Hilton Head is principally pro-
vided by designated public service districts, which have been established by
state enabling legislation. Four public service districts comprise the island
as follows:
Sea Pines Public Service District
. Forest Beach Public Service District
Broad Creek Public Service District
. Hilton Head No. 1 Public Service District
Each public service district (PSD) operates its own wastewater treatment and disposal
facilities, with the exception of the Forest Beach Public Service District.
Wastewater is conveyed from Forest Beach to the Sea Pines Public Service Dis-
trict for treatment and disposal.
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Hilton Head Plantation is served by treatment facilities owned and op-
erated by the Hilton Head Plantation Utilities Corporation. Several small,
privately-owned treatment facilities are located elsewhere on the island
which provide service to isolated residential or resort areas. These include
the Mariner's Cove plant and the Port Royal Inn plant which lies within the
boundaries of the Hilton Head No. 1 Public Service District. The Long Cove
Club, now under development, will be served by its own wastewater facilities.
The remaining rural areas of the island utilize septic tank-drainfield systems.
Treated wastewater from the wastewater facilities on the island is
disposed of by several methods. To a large extent, treated wastewater is
used to irrigate the golf courses on the island. In a few cases, treated waste-
water is sprayed onto areas of open land as a supplement to golf course ir-
rigation However, present wastewater flows from the Sea Pines PSD - Forest
Beach PSD exceed the total irrigation demands of the golf courses located within
Sea Pines and Shipyard Plantations. As a result, up to 1.8 million gallons per
day (mgd) of treated wastewater are discharged into Lawton Canal and thence
to Lawton Creek which is classified for shellfishing.
The 201 Facilities Plan, completed in 1975, recommended that the effluent
from all treatment plants be disposed of by spray irrigation on nearby golf
courses so as not to impact area shellfish waters. While conceptually sound,
this scheme was based upon golf course irrigation rates which have proved to
be optimistic, particularly in the case of the Sea Pines PSD and the Forest
Beach PSD. The continued ability of the other PSD's on the island to dispose
of their treated wastewater by golf course irrigation will depend upon the
actual rate of development experienced within each.
In August 1978 the South Carolina Department of Health and Environmental
Control (DHEC) closed shellfish beds in Lawton Canal and Lawton Creek, in
Point Comfort Creek, and in adjacent waters of Broad Creek. These areas were
closed because of high total and fecal coliform counts encountered in surface
water samples. Subsequent water quality studies confirmed that shellfish
standards were being violated; findings indicated that these violations were
attributable to non-point source bacterial contamination.
Because of these environmental complexities and the uniqueness of Hilton
Head as a barrier island, the Environmental Protection Agency decided to pre-
pare an Environmental Impact Statement with respect to wastewater management
facilities to serve the existing and future populations of Hilton Head Island.
Subsequently, a Notice of Intent was issued by the EPA Regional Administrator
in April, 1979. Concurrent with the Hilton Head EIS, the South Carolina
DHEC initiated a study of the Lawton Creek - Broad Creek watershed in order to
better define the extent to which non-point and point sources influence their
bacterial characteristics. These studies confirmed the existence and magnitude
of non-point contamination of Lawton Creek. Only the effluent from the Sea
Pines treatment plant met water quality standards with any consistency.
Additional non-point work is now underway through the 208 program. The
firm of Moore Gardner § Associates is performing the work under the direction
of an advisory committee representing local, state, and Federal governments.
The focus of the study is to develop effective management practice which will
abate non-point pollution from island developments. Conclusions from this
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work will serve as an adjunct to the findings of this EIS regarding wastewater
management.
PART B. DESCRIPTION OF ALTERNATIVES
The EIS was initiated in late May, 1979. The focus of the EIS was to
develop and evaluate wastewater management systems for the island which would
accommodate projected populations, with emphasis placed on the method of
disposal of treated wastewater. The methods generally available include golf
course irrigation, discharge to surface waters, land application by either
spray irrigation or rapid infiltration, and discharge to wetlands.
Projected populations and wastewater flows were developed for each of
the service areas on the island and compared with on-going wastewater facility
construction. Wastewater management alternatives were then formulated and
evaluated with respect to costs, environmental consequences, operability, and
implementability. Where on-going wastewater facility construction met or
exceeded projected wastewater flows, the "no action" alternative with respect
to EPA funding was judged to be the only alternative. Alternatives evaluated
for each service area are discussed below.
1. SEA PINES PSD - FOREST BEACH PSD
Five wastewater management alternatives have been formulated for the Sea
Pines PSD - Forest Beach PSD. Each alternative includes treatment at the
Sea Pines PSD plant which is now being expanded to 3.25 mgd, irrigation of
the five golf courses within the two PSD's, and the experimental wetlands dis-
charge system which has already been approved in concept by the South Carolina
DHEC and Coastal Council.
Even with irrigation of all five golf courses, a substantial amount of
wastewater will remain which must be handled by supplemental means. The
five alternatives are based on the following methods of disposal: (1) advanced
treatment and discharge to Lawton Canal; (2) secondary treatment and discharge
to Calibogue Sound via a subaqueous outfall and diffuser; (3) land application
within the PSD's using a combination of spray irrigation at parcels within
Forest Beach PSD immediately adjacent to the Hilton Head Golf Club, rapid in-
filtration within the Forest Preserve, and the experimental wetlands discharge
system handling 1 mgd; (4) land application outside the PSD's by woodlands ir-
rigation on the Gardner-Matthews tract; and (5) land application on the main-
land by spray irrigation. Funding options for these alternatives were also
considered, including 100 percent local funding and Federal funding contingent
on non-point source control. Table ES-1 summarizes the costs, environmental
impacts, and implementability of each.
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TART.F. ES-1
SEA PINES PSD - FOREST BEACH PSD
SUMMARY OF ALTERNATIVES EVALUATION
Alternative
A. Discharge to Lawton
Canal
Cost
(Total Present Worth)
$1,861,900
Environmental Impacts
1. Increase in size of areas closed to
shellfishing will be required due to
increased wastewater flows into SA
waters,
2. Wastewater disposal would be
eliminated as a constraint to
population growth in the Sea
Pines - Forest Beach Area.
3. Selection of this alternative would
provide a precedent for the
approval of additional surface
water discharges of wastewater.
4. Selection of this alternative would
provide federal support for
population growth potentially
causing increased urban runoff
into SA waters.
S. A precedent of near-shore waste-
water disposal could encourage
other developments to abandon
on-property disposal plans
potentially resulting in a
reduction of open space and
higher densities.
Implementability
1. NPDES permit required from DHEC.
2. New buffer zone boundary for
discharge to shellfish waters
must be established.
B.
Discharge to Calibogue
Sound
$1,818,300 1. The discharge of treated wastewater
into the SA waters of Lawton Canal
and Broad Creek would be eliminated.
2. Wastewater disposal would be
eliminated as a constraint to
population growth in the Sea Pines -
Forest Beach Area.
1. NPDES permit required from DHEC.
2. Permit required from Coastal Council.
3. Detailed studies needed during
Step II to determine outfall pipe
alignment and diffuser orientation.
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TABLE ES-1
(con'd)
SEA PINES PSD - FOREST BEACH PSD
SUMMARY OF ALTERNATIVES EVALUATION
Alternative
B. Discharge to Calibogue
Sound (continued)
Cost
(Total Present Worth)
Environmental Impacts
3. Selection of this alternative would
provide a precedent for the approval
of additional surface water discharges
of wastewater.
4. Selection of this alternative would
provide Federal support for popu-
lation growth potentially causing
increased urban runoff into SA waters.
5. A precedent of off-island wastewater
disposal could encourage other develop-
ments to abandon on-property disposal
plans potentially resulting in a
reduction of open space and higher
densities.
Implementability
C. Rapid Infiltration
within Sea Pines
Forest Preserve and
spray irrigation
within Shipyard
Plantation.
$6,757,000
1.
2.
3.
4.
5.
6.
This system is not technically feasible
due to soil and water table conditions.
The discharge of treated wastewater
into the SA waters of Lawton Canal
and Broad Creek would be eliminated.
Selection of this alternative would
not provide a precedent for the approval
of additional surface water discharges of
wastewater.
Wastewater disposal would be eliminated
as a constraint to population growth in
the Sea Pines - Forest Beach Area.
Selection of this alternative would pro-
vide Federal support for population growth
potentially causing increased urban runoff
into SA waters.
This alternative would utilize 67 acres
of otherwise developable land.
1. Sea Pines PSD must exercise
power of eminent domain to
acquire land.
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TABLE ES-1
(con'd)
SEA PINES PSD - FOREST BEACH PSD
SUMMARY OF ALTERNATIVES EVALUATION
Alternative
D. Land application at
Gardner Matthews
site
Cost
(Total Present Worth)
$12,609,000
Environmental Impacts
1. The discharge of treated wastewater
into the SA waters of Lawton Canal
and Broad Creek would be eliminated.
2. Wastewater disposal would be
eliminated as a constraint to
population growth in the Sea Pines -
Forest Beach Area up to the
capacity of the spray irrigation
field.
3. Selection of this alternative would
not provide a precedent for the
approval of additional surface water
discharges of wastewater.
4. Selection of this alternative would
provide Federal support for popula-
tion growth potentially causing
increased urban runoff into SA waters.
5. This alternative would utilize 500
acres of otherwise developable land.
Implementability
Beaufort County must exercise
power of eminent domain to ac-
quire land for PSD use.
Site specific studies will be
required to determine specific
spray irrigation application
rate.
E. Off-Island Land
application
$12,576,100 1. The discharge of treated wastewater
into the SA waters of Lawton Canal
and Broad Creek would be eliminated.
2. Wastewater disposal would be elimi-
nated as a constraint to population
growth in the Sea Pines - Forest Beach
Area up to the capacity of the off-
island force main.
3. Selection of this alternative would not
provide a precedent for the approval of
additional surface water discharges of
wastewater.
4. Selection of this alternative would pro-
vide Federal support for population growth
potentially causing increased urban runoff
into SA waters.
Beaufort County may be required to
exercise power of eminent domain
to acquire land for PSD use.
Site specific studies will be
required to determine specific
spray irrigation application
rate.
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TABLE ES-1
(con'd)
SEA PINES PSD - FOREST BEACH PSD
SUMMARY OF ALTERNATIVES EVALUATION
Alternative
Cost
(Total Present Worth)
E. Off-Island Land
application (continued)
Environmental Impacts
A precedent of off-island wastewater
disposal could encourage other develop-
ments to abandon on-property disposal
plans potentially resulting in a re-
duction of open space and higher densities.
Implementability
F. No Federal Action.
The Sea Pines -
Forest Beach PSD
would implement
either alternative
B, D, or E with
100% local funding
H-
H-
Cost as presented for
alternatives B, D, or
E.
!.• The discharge of treated wastewater into
the SA waters of Lawton Canal would be
eliminated.
2. Federal participation would not be
provided to any alternative which
would support increased urban runoff
into SA waters.
3. Wastewater disposal would be eliminated
as a constraint to population growth in
the Sea Pines - Forest Beach Area up to
the capacity of the spray site or outfall.
4. Implementation of a discharge to Calibogue
Sound would provide a precedent for other
surface water discharges.
Beaufort County might be required
to exercise power of eminent
domain for Alternatives D or E.
Permits would be required from
Coastal Council and DHEC for
Alternative B.
Site specific studies would be
required on the locally selected
alternative to determine spray
application rate or exact outfall
pipe location.
G. Federal funding con- Cost as presented for
ditional on non-point alternatives B, D, or
source solution. This E.
option would be identi-
cal to Option F except
that Federal funding
would be made available
if an effective
implementable non-
point source program is
established.
1. This alternative could provide incentive 1.
for the implementation of an effective
non-point source program.
2. The discharge of treated wastewater into 2.
the SA waters of Lawton Canal would be
eliminated.
3. Federal participation would not be pro- 3.
vided to any alternative which would
support increased urban runoff into SA
waters.
4. Wastewater disposal would be eliminated as
a constraint to population growth in the
Sea Pines - Forest Beach Area up to capacity
of the spray site or outfall.
5. Implementation of a discharge to Calibogue
Sound would provide n precedent for other
surface water discharges.
Beaufort County might be required to
exercise power of eminent domain for
alternatives D or E.
Permits would be required from the
Coastal Council and DHEC for
Alternative B.
Site specific studies would be required
on the locally selected alternative
to determine spray application rate
or exact outfall pipe location.
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A cost comparison of these five alternatives is presented below.
Alternative
Lawton Canal
Calibogue Sound
Rapid Infiltration
Spray Irrigation at
Gardner-Matthews
Site
Spray Irrigation at
Off-Is land Site
Project
Cost
$ 1,777,300
$ 2,033,900
$ 7,862,400
$14,928,700
$13,827,000
Annual
0 § M
$ 37,400
$ 17,200
$ 81,000
$103,100
$123,700
Net Present
Worth
$ 1,861,900
$ 1,818,300
$ 6,757,000
$12,609,000
$12,576,100
Of additional concern in the evaluation of alternatives is the estimated in-
crease in user costs, and the local implications of the differences. These
estimates are presented below based upon EPA funding of facilities sized to
dispose of the 1.8 mgd now being discharged to Lawton Canal.
Alternative
Lawton Canal
Calibogue Sound
Rapid Infiltration
Spray Irrigation On-Island
Spray Irrigation Off-Island
Estimate Additional Annual User Cost
EPA Funding
17.70
16.75
$ 48.23
$117.26
$108.59
No EPA Funding
$ 37.64
$ 40.69
$158.64
$296.50
$277.26
Each of the alternatives for the Sea Pines PSD - Forest Beach PSD is
summarized below.
Option A:
Continued discharge to Lawton Canal.
1. Total present worth cost of $1.8 million.
2. This alternative would allow continued discharge to shellfish
waters when other reasonable options are available. This would
foreclose the chance of opening the closed shellfish waters if
the non-point source problem is resolved in the future. The
memorandum enclosed in Appendix A indicates the position of the
EPA Water Quality Standards Section.
3. The size of the closed buffer zone will increase as the wastewater
flow increases. See Plate ES-1 for the buffer zone areas.
4. The selection of this alternative will set a precedent allowing
surface discharges into shellfish waters.
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5. Federal support would promote growth and development which would
increase non-point source runoff.
6. A precedent of near-shore wastewater disposal could encourage
other developments to abandon on-property disposal plans
potentially resulting in a reduction of open space and higher
densities.
Option B:
Construction of a new subaquaeous outfall for discharge to Calibogue Sound.
1. Total present worth cost of $1.8 million.
2. Removal of unpermitted discharge to shellfish waters.
3. No buffer zone closures of shellfish beds required.
4. The S. C. Wildlife and Marine Resources Department has expressed
concerns regarding surface water discharges to the area. See
enclosed comment letter from this agency in Appendix B.
5. The S. C. Coastal Council has expressed concern regarding a precedent
for surface discharges and greater long-range non-point source pro-
blems based on greater ultimate population.
6. Federal support would promote growth and development which will
increase non-point source runoff.
7. A precedent of off-island wastewater disposal could encourage other
developments to abandon on-property disposal plans potentially
resulting in a reduction of open space and higher densities.
Option C:
"a±ion?he "" """ *"•" P"Ie™ and *
1. Total present worth cost is $6.7 million.
2. This system is not technically feasible due to soil and water
table conditions.
3. Removal of unpermitted discharge to shellfish waters.
4. No precedent set for surface discharge.
5. Federal support would promote growth and development which will
increase non-point source runoff.
6. 67 acres of land within Shipyard Plantation will no longer be
available for development.
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Option D:
Spray irrigation on Gardner-Matthews site.
1. Total present worth cost is $12.6 million.
2. Removal of unpermitted discharge to shellfish waters.
3. Increase in disposal capacity limited by capacity of spray site.
4. Selection of this alternative will not provide a precedent for the
approval of additional surface water discharges of wastewater.
5. Federal support would promote growth and development which
would increase non-point source runoff.
6. Powers of eminent domain would have to be used to take land from
land owner who currently has other plans for its use.
7. Site specific studies will be required to determine specific
spray irrigation application rate.
8. This alternative gives the perception of a solution to the
wastewater disposal problem that is limited in scope. Therefore
future developments would likely be planned to manage their waste-
water disposal on their own property.
9. 500 acres of land will no longer be available for development.
Option E:
Spray irrigation off-island.
1. Total present worth cost of this alternative is $12.5 million.
2. Removal of unpermitted discharge to shellfish waters.
3. Selection of this alternative will not provide a precedent for the
approval of additional surface water discharges of wastewater.
4. The purchase or lease of land could potentially be negotiated
without the use of eminent domain.
5. A precedent of off-island wastewater disposal could encourage
other developments to abandon on-property disposal plans potentially
resulting in a reduction of open space and higher densities.
6. Federal support would promote growth and development which would
increase non-point source runoff.
7. Site specific studies will be required to determine specific
spray irrigation application rates.
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Option F:
No Federal Action. The Sea Pines - Forest Beach PSD would implement
either Alternative B, D, or E with 100% local funding.
1. The discharge of treated wastewater into the SA waters of Lawton
Canal would be eliminated.
2. Federal participation would not be provided to any alternative which
would support increased urban runoff pollution of SA waters.
3. Implementation of a discharge to Calibogue Sound would provide
a precedent for other surface water discharges.
4. Site specific studies would be required on the locally selected
alternative to determine spray application rate or exact outfall
pipe alignment and diffuser orientation.
Option G:
Federal funding conditional on non-point source solution. This option would
be identical to Option F except that Federal funding would be made available
if an effective implementable non-point source control program is established.
1. The discharge of treated wastewater into the SA waters of Lawton
Canal would be eliminated.
2. Federal participation would not be provided to any alternative
which would support increased urban runoff pollution of SA waters.
3. Implementation of a discharge to Calibogue Sound would provide
a precedent for other surface water discharges.
4. Site specific studies would be required on the locally selected
alternative to determine spray application rate or exact outfall
pipe alignment and diffuser orientation.
5. This alternative could provide incentive for the implementation
of an effective non-point source program.
6. Delays final selection of project and determination of eligibility
for Federal funding.
2. BROAD CREEK PSD
Present plans of the Broad Creek PSD envision expansion of the existing
0.6 mgd treatment plant to 1.2 mgd in 1981-1982. A second expansion from
1.2 to 1.8 mgd is envisioned by July 1984 and a third from 1.8 to 2.4 mgd by
1988. These plans will provide capacity beyond that required for the year
2000 OBERS population (0.64 mgd) or JPC population (0.81 mgd).
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Wastewater is presently sprayed onto the Fazio golf course and an ex-
isting 20-acre spray site. As needs dictate, the Trent Jones golf course
will also be irrigated with treated wastewater. These two courses and the
existing 20-acre spray site are adequate to handle the OBERS and JPC-based
flows projected for the year 2000. However, additional spray areas may be
required to match the design capacity of the proposed 1.2 mgd plant or pro-
visions made for a subaqueous discharge to Port Royal Sound.
The costs of the Broad Creek expansion program must be borne entirely
at the PSD level. Current EPA policy prevents their participation in funding
of wastewater facilities greater than the OBERS population. Consequently,
the program described above for the Broad Creek PSD represents the no-action
alternative with respect to federal funding.
5. HILTON HEAD NO. 1 PSD
The Hilton Head No. 1 PSD wastewater facilities primarily serve apartments,
condominiums, and commercial establishments located within the boundaries of
the PSD. Single-family residences within the Port Royal Plantation (except
two) are served by septic tanks. Current flows average about 175,000 gpd.^
Treatment facilities were constructed in 1971 and consist of an unlined oxi-
dation pond followed by two unlined holding ponds. Wastewater from the oxi-
dation pond percolates radially into the groundwater, and DHEC has placed a
moratorium on additional connections to the system.
In order to provide additional capacity, private development has con-
structed an interim 440,000 gpd treatment facility adjacent to the PSD's ex-
isting oxidation pond. Treated effluent is pumped from the plant, under
Route 278, to Port Royal Plantation for irrigation of the Barony and Robbers
Row golf courses. DHEC has approved the use of these courses for the spray
irrigation of at least 800,000 gpd of wastewater.
Construction is now underway on a new 800,000 gpd plant to serve existing
and future needs within the service area. Completion is scheduled for February
1982. A completely new facility is being built because of the inadequacy of the
existing unlined oxidation pond. As part of the Hilton Head No. 1 project,
the Port Royal Inn package plant will be abandoned and a pumping station and
force main constructed to convey wastewater to the new PSD facilities. The
entire project is being funded, in part, by the EPA Construction Grants Program.
The Hilton Head No. 1 PSD has recently asked DHEC to allow the 440,000
gpd "interim" facility to remain in operation after construction of the new
800,000 gpd plant has been completed. However, the existing Barony and Robbers
Row golf courses cannot accommodate the total capacity of 1.24 mgd which
would result, although a third golf course in the Port Royal Plantation is
planned for construction by the Hilton Head Company within the next four
years.
Additional EPA funding will not be available for any future needs of
the Hilton Head No. 1 PSD in excess of the 800,000 gpd facilities now under
XII
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construction (no action alternative). Therefore, the costs for further ex-
pansion of the Hilton Head No. 1 PSD treatment facilities beyond 800,000 gpd
and for securing additional spray irrigation areas or for surface discharge
to Port Royal Sound must be borne by the PSD.
4. HILTON HEAD PLANTATION
Hilton Head Plantation is served by treatment facilities owned and
operated by the Hilton Head Plantation Utilities Corporation. The Hilton
Head Plantation plans to expand the existing 0.5 mgd activated sludge package
plant to 1.0 mgd during 1984, based upon anticipated housing starts. The
resulting capacity will be sufficient to accommodate the year 2000 population
which the plantation projects. The corporation is not eligible to receive EPA
grant funds for improvements and/or additions to wastewater facilities.
5. NON-PSD AREAS
Areas of Hilton Head Island which lie outside the boundaries of the Hilton
Head Plantation or the existing PSD's are served by septic tank-drainfield
systems, with the exception of the Mariner's Cove Club and the Northside Trailer
Park. There are no areas where widespread septic tank malfunctions are known to
occur.
The septic tank-drainfield system remains the preferred system for use
in the non-PSD areas where soils, groundwater depth, and site conditions are
acceptable. If an area should experience septic tank failures in the future
a community-sized on-lot system could be developed, or sewers extended from '
an adjacent PSD. Where septic tank failures occur on an individual basis on-
site improvements would be the only feasible action.
The Mariner's Cove plant provides treatment for the wastewater generated
from forty units of the Mariner's Cove Club complex, which is located south
of Route 278 near the bridge to Pinckney Island. Effluent from the plant is
spray irrigated. Its continued operation is envisioned although increased
emphasis on operation and maintenance of the plant and spray system is re-
quired.
The Northside Trailer Park is located on the north end of Hilton Head,
off of Gumtree Road. Residents of the trailer park have been asked by the
^nnn "^ Plantation Company to vacate the property after which the existing
10,000 gpd package plant will be abandoned.
PART C. PREFERRED ALTERNATIVE
1. SEA PINES PSD - FOREST BEACH PSD
The preferred wastewater management alternative for the Sea Pines PSD -
Forest Beach PSD is the Federal funding conditional on non-point source solution
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alternative. Under this alternative the Sea Pines PSD would implement the most
cost-effective, implementable of these disposal options: discharge to Calibogue
Sound, spray irrigation at the Gardner Matthews site, or spray irrigation off-
island Federal funding for construction would be made available consistent
with State priority listing, if an effective non-point source program was de-
veloped for the Sea Pines - Forest Beach area by the time the Step II design
phase was complete. Detailed studies will be needed during Step II to locate
an outfall and diffuser structure for the Calibogue Sound alternative. If either
of the spray irrigation alternatives is selected, site specific studies to
determine the appropriate specific application rate will be required.
If Federal funding is made available for Step III, facilities sized to
dispose of the 1.8 mgd now going into Lawton Canal will be eligible. Any
additional capacity constructed would have to be funded with 100 percent local
funding.
2. OTHER AREAS OF THE ISLAND
As previously explained, the other PSD's are not eligible for Federal
funding based upon the OBERS funding formula. Therefore, any facilities con-
structed in the near future must be done with 100 percent local funding. If
appropriate planning is undertaken now by these PSD's, wastewater facilities
should become available as the need arises.
The control of non-point source pollution is actually the major environ-
mental problem on the island. This problem will grow continually worse in
other areas of the island if control measures are not initiated now before
development intensifies. The implementation of appropriate non-point controls
such as on-lot retention and treatment through natural wetlands systems could
significantly mitigate non-point source problems.
Septic tank-drainfield systems remain the preferred alternative for the
non-PSD areas where soils, groundwater depth, and site conditions are acceptable,
Solutions and costs for areas which experience malfunctions in the future will
depend on the extent of the problem area, the affected population, and develop-
ment plans for contiguous areas.
PART D. BASIS FOR DECISION
The purpose of this EIS is to select a wastewater management program for
Hilton Head Island that is compatible with the protection of the area s sensi-
tive resources, particularly water quality, while recognizing the existing
extensive development pressure. The work accomplished as part o± this bib
has determined that non-point source pollution is a more severe problem on
the island than point source pollution. The EIS has also determined that dis-
charge to Calibogue Sound and the two spray irrigation options are environ-
mentally acceptable. In light of these findings, EPA selected the P6^
funding conditional on a non-point source solution alternative as the preferred
alternative for the Draft EIS. This is the only alternative which provides
encouragement for developing a solution to the non-point source problem.
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DRAFT ENVIRONMENTAL IMPACT STATEMENT
HILTON HEAD ISLAND WASTEWATER FACILITIES
TABLE OF CONTENTS
EXECUTIVE SUMMARY
PART A. EXISTING PROBLEM
PART B. DESCRIPTION OF ALTERNATIVES
1. SEA PINES PSD - FOREST BEACH PSD
2. BROAD CREEK PSD
3. HILTON HEAD NO. 1 PSD
4. HILTON HEAD PLANTATION
5. NON-PSD AREAS
PART C. PREFERRED ALTERNATIVE
1. SEA PINES PSD - FOREST BEACH PSD
2. OTHER AREAS OF THE ISLAND
PART D. BASIS FOR DECISION
CHAPTER I. PURPOSE OF AND NEED FOR ACTION
CHAPTER II. ALTERNATIVES DEVELOPMENT AND EVALUATION
PART A. INTRODUCTION
PART B. POPULATION AND WASTEWATER FLOW PROJECTIONS
1. POPULATION PROJECTION
2. PERCENT SEWERED
3. PER CAPITA WASTEWATER FLOWS
4. SUMMARY OF WASTEWATER FLOWS FOR YEAR 2000
PART C. IDENTIFICATION OF AVAILABLE DISPOSAL METHODS
1. TREATMENT AND LAND APPLICATION
2. TREATMENT AND DISCHARGE
3. TREATMENT AND WETLANDS DISCHARGE
4. SYSTEMS FOR UNSEWERED AREAS
PART D. NON-STRUCTURAL WASTEWATER MANAGEMENT CONSIDERATIONS
1. OPTIMUM USE OF EXISTING FACILITIES
2. FLOW AND WASTE REDUCTION MEASURES
3. LAND USE AND DEVELOPMENT CONTROLS
4. NON-POINT SOURCE POLLUTION
Page
i
iii
iii
xi
xii
xiii
xiii
xiii
xiii
xiv
xiv
1-1
II-l
II-l
II-l
II-2
II-2
II-2
II-3
II-3
II-3
II-7
II-9
II-9
11-11
11-12
11-12
11-14
11-15
xv
-------
TABLE OF CONTENTS (Cont'd.)
PART E. WASTEWATER MANAGEMENT ALTERNATIVES
1. SEA PINES PSD - FOREST BEACH PSD
2. BROAD CREEK PSD
3. HILTON HEAD NO. 1 PSD
4. HILTON HEAD PLANTATION
5. NON-PSD AREAS
CHAPTER III.
PART A.
PART B.
AFFECTED ENVIRONMENT, ENVIRONMENTAL CONSEQUENCES
OF THE ALTERNATIVES AND MITIGATIVE MEASURES
INTRODUCTION
PRIMARY IMPACTS
1. SURFACE WATER RESOURCES
2. GROUNDWATER RESOURCES
3. ECOLOGICAL RESOURCES
4. AQUATIC SYSTEMS
5. POPULATION AND LAND USE
6. ECONOMICS
7. ARCHEOLOGICAL AND HISTORICAL
8. NOISE
PART C. SECONDARY IMPACTS
1. LAND USE
2. ECONOMICS
3. TRANSPORTATION
4. COMMUNITY SERVICES AND FACILITIES
5. WATER QUALITY
PART D. MITIGATIVE MEASURES
1. SURFACE WATER QUALITY
2. SURFACE WATER QUANTITY
3. GROUNDWATER QUALITY AND QUANTITY
4. TERRESTRIAL ECOSYSTEMS
5. AQUATIC ECOSYSTEMS
6. POPULATION
7. LAND USE
8. CULTURAL RESOURCES
9. RECREATION
10. TRANSPORTATION
11. COMMUNITY SERVICES AND FACILITIES
Page
11-15
11-15
11-35
11-38
11-40
11-41
III-l
III-l
III-l
III-l
III-3
III-4
III-5
III-6
III-6
III-7
III-7
III-7
111-10
111-16
111-17
111-18
111-19
111-20
111-20
111-21
111-21
111-21
111-21
111-22
111-22
111-22
111-22
111-23
111-23
xvi
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TABLE OF CONTENTS (Cont'd.)
-^32.
CHAPTER IV. DESCRIPTION OF THE PREFERRED ALTERNATIVE Iv_i
PART A. INTRODUCTION
PART B. SEA PINES PSD - FOREST BEACH PSD Jy~j
1. DESCRIPTION OF ALTERNATIVE Tv 0
2. COSTS *
3. IMPLEMENTATION *X~*
4. SPECIAL STUDIES !. ,7
IV-4
PART C. OTHER PSD'S
PART D. MITIGATIVE MEASURES JjJ'f
1. MITIGATIVE MEASURES FOR PRIMARY IMPACTS TV i
2. MITIGATIVE MEASURES FOR SECONDARY IMPACTS
CHAPTER V. EIS COORDINATION
uix^o rui\ OCLU1NUAKI IMFALTS IV-6
V-l
PART A. INTRODUCTION
PART B. CONCERNS EXPRESSED BY OTHER PUBLIC AGENCIES OR y'l
INSTITUTIONS
1. STATE AGENCIES
2. REGIONAL PLANNING AGENCY V ?
3. LOCAL GOVERNMENT X ,
4. PUBLIC SERVICE DISTRICTS ^2
PART C. CONCERNS EXPRESSED BY INDIVIDUALS AND PRIVATE GROUPS V-3
PART D. PUBLIC PARTICIPATION PROGRAM v_4
CHAPTER VI. LIST OF PREPARERS
APPENDIX A. MEMORANDUM FROM EPA WATER QUALITY STANDARDS SECTION A-l
APPENDIX B. LETTER FROM SOUTH CAROLINA WILDLIFE AND MARINE R i
RESOURCES DEPARTMENT MAKiNt B-l
APPFNDTY C TCTTnn rr>/iw r^, ™.
Af^tMulx L. LETTER FROM SOUTH CAROLINA DEPARTMENT OF
APPENDIX D. " ATTORNHV GENERA1 POR THE
XVI1
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Table
DRAFT ENVIRONMENTAL IMPACT STATEMENT
HILTON HEAD ISLAND WASTEWATER FACILITIES
LIST OF TABLES
Page
ES-1 Sea Pines PSD - Forest Beach PSD, Summary of iv
Alternatives Evaluation
II_1 Wastewater Flow Projections for Year 2000 H-4
II-2 Effluent Requirements for Discharges to Surface H-8
Waters
H_3 Summary of Indoor Residential Water - Saving 11-13
Devices
II-4 Wastewater in Excess of Golf Course Irrigation H-18
Needs for Sea Pines PSD - Forest Beach PSD
H-5 Sea Pines PSD - Forest Beach PSD, Land Application 11-20
Capacities for Disposal Components of Rapid
Infiltration Alternative
H-6 Sea Pines PSD - Forest Beach PSD, Land Application II-22
• Capacities for Disposal by On-Island Spray
Irrigation Alternative
II-7 Cost Summary for 2.55 MGD Discharge from Sea Pines 11-25
PSD - Forest Beach PSD to Lawton Canal
II-8 Cost Summary for 2.55 MGD Discharge from Sea Pines 11-26
PSD - Forest Beach PSD to Calibogue Sound
II-9 Cost Summary for 2.55 MGD Discharge from Sea Pines 11-27
PSD - Forest Beach PSD by Rapid Infiltration
II-10 Cost Summary for 2.55 MGD Discharge from Sea Pines 11-28
PSD - Forest Beach PSD by Spray Irrigation On-Island
at Gardner-Matthews
II-ll Cost Summary for 2.55 MGD Discharge from Sea Pines 11-29
PSD - Forest Beach PSD by Spray Irrigation Off-Island
at Union Camp
II-12 Cost Summary for Sea Pines PSD - Forest Beach PSD H-30
Wastewater Management Alternatives
H-13 Sea Pines PSD - Forest Beach PSD Wastewater H-32
Management Alternatives, Operability Evaluation
xvi 11
-------
LIST OF TABLES (Cont'd.)
Table
Page
11-14 Local Annual Cost Summary for Sea Pines PSD - 11-34
Forest Beach PSD Wastewater Management Alternatives
11-15 Estimated User Cost Summary for Sea Pines PSD - 11-36
Forest Beach PSD Wastewater Management Alternatives
11-16 Non-PSD Communities, Wastewater Management 11-43
Alternatives, Total Annual Local Costs
111-1 Disaggregation of Year 2000 Population for Hilton III-8
Head Island - JPC Base
HI-2 Disaggregation of Year 2000 Population for Hilton III-9
Head Island - OBERS Base
111-3 Hilton Head Island, Summary of Existing L ind Use III-ll
by Acres and Percent Use
111-4 Hilton Head Island - Plantation Dwelling Units 111-13
at Build Out
III-5 Hilton Head Island - Existing and Known Planned 111-14
Commercial Acreage and Estimated Retail Floor Area
111-6 Hilton Head Island - Existing, Known Planned, and 111-15
Estimated Islandwide Build Out of Residential
and Hotel Construction
IV-1 Sea Pines PSD - Forest Beach PSD, Description of IV-3
Facilities Required for Environmentally Acceptable
Alternatives
V-l EIS Review Committee V-5
VI-1 List of Preparers VI_
xix
-------
DRAFT ENVIRONMENTAL IMPACT STATEMENT
HILTON HEAD ISLAND WASTEWATER FACILITIES
LIST OF PLATES
Plate
ES-1
1-1
II-1
II-2
II-3
III-l
III-2
III-3
III-4
Existing and Future Buffer Zones
for Lawton Canal Discharge
Wastewater Facilities and Disposal
Areas
Receiving Streams and Buffer Zones
Wando Soils and Septic Tank Areas
Off-Island Spray Irrigation Areas
Location of Sampling Stations
Existing Land Use
Plantations and Heir's Property
Future Land Use
Following
Page
viii
1-1
II-8
11-10
11-22
III-2
111-10
111-13
111-14
xx
-------
DRAFT ENVIRONMENTAL IMPACT STATEMENT
HILTON HEAD ISLAND WASTEWATER FACILITIES
LIST OF FIGURES
Following
Figure Page
II-l Sea Pines PSD - Forest Beach PSD, 11-17
Wastewater Flow vs. Irrigation
Capacity
II-2 Water Depths of Calibogue Sound 11-18
and Atlantic Ocean
II-3 Sea Pines PSD - Forest Beach PSD, 11-18
Lawton Canal Discharge
II-4 Sea Pines PSD - Forest Beach PSD, 11-18
Calibogue Sound Discharge
II-5 Sea Pines PSD - Forest Beach PSD, 11-19
Rapid Infiltration Alternative
H-6 Sea Pines PSD - Forest Beach PSD, 11-21
Spray Irrigation On-Island
II-7 Sea Pines PSD - Forest Beach PSD, 11-22
Spray Irrigation Off-Island
H-8 Wastewater Treatment § Disposal 11-42
Costs for Non-PSD Areas
xxi
-------
-------
CHAPTER I
PURPOSE AND NEED FOR ACTION
-------
-------
CHAPTER I - PURPOSE OF AND NEED FOR ACTION
The Hilton Head Island Environmental Impact Statement is being prepared
to address the provision of wastewater management facilities to serve existing
and future needs.
Hilton Head Island lies off of the southeastern tip of South Carolina
about 30 miles northeast of Savannah, Georgia. Hilton Head is one of the
barrier islands along the Atlantic and Gulf Coasts and is the largest ocean-
front island between New York and Florida. The island is approximately twelve
miles long, up to five miles wide, and covers approximately forty-two square
miles. n
The Atlantic Ocean borders Hilton Head to the east, Calibogue Sound
to the south, and Port Royal Sound to the north. Skull Creek, which comprises
a link of the Intracoastal Waterway, separates Hilton Head from the mainland.
Broad Creek, a seven-mile tidal inlet which opens to Calibogue Sound, runs
diagonally across the island. Plate 1-1 illustrates these features.
Hilton Head Island is largely devoted to resort development. Over half
the island has been developed according to the "plantation" concept. These
planned unit developments contain residential, recreational, and occasional
neighborhood commercial land uses. A second type of development is also
resort-oriented but made up of apartments and condominium complexes. A third
type of development is rural residential, found on lands owned by persons who
resided on the island before resort development was undertaken. Nodes of
commercial and office/institutional development which serve island residents
and visitors are located along Highway 278 near Hilton Head Plantation, at
Sea Pines Circle, at Forest Beach, and at Pineland Mall. The Harbour Town
shopping district is located within the gates of Sea Pines Plantation.
Wastewater collection and treatment for the island is principally pro-
vided by designated public service districts, which have been established by
State enabling legislation. Four public service districts (PSD's) are
located on the island.
. Sea Pines Public Service District
Forest Beach Public Service District
. Broad Creek Public Service District
. Hilton Head No. 1 Public Service District
Each public service district (PSD) operates its own wastewater treatment and
disposal facilities, with the exception of the Forest Beach PSD. Wastewater
is conveyed from Forest Beach to the Sea Pines PSD for treatment and disposal
1-1
-------
-------
Gannett Fleming Corddry $ Carpenter, Inc./Claude Terry and Associates
was selected by EPA to prepare the EIS. Meetings were held on the island
on May 22 and 23, 1979 to solicit the views of state and local agencies,
interested groups, and concerned citizens. A public scoping meeting was
held on June 28, 1979 to receive additional input from the Hilton Head
residents.
During the EIS process a number of major issue areas were identified.
The following issues were determined to be the most significant:
1. The identification of a method or combination of methods for dis-
posal of treated wastewater effluent, adequate for year 2000
capacity and compatible with the water quality standards desig-
nated by the South Carolina Department of Health and Environmental
Control (DHEC),
2. The determination of the capacity for spray irrigation of treated
wastewater effluent on the island and the impacts resulting from
this wastewater disposal alternative,
3. The magnitude and causes of non-point source pollution on the
island and the relationship of this pollution source to the evalu-
ation of alternatives,
4. The extent and cause of septic tank failures on the island,
5. The disparity between OBERS Series E population projections and
indicated trends based on historical growth, platted property
holdings, and developer's plans and the resulting disparity in
future wastewater flow projections as it impacts the need for
wastewater treatment and disposal facilities, and
6. The impacts from growth supported by the provision of wastewater
facilities and measures to minimize adverse effects from pro-
jected development.
Concurrent with the Hilton Head EIS, the South Carolina DHEC conducted
a study of the Lawton Creek - Broad Creek watershed to better define the
extent to which non-point and point sources influence their bacterial
characteristics. Water quality and bacteria samples were collected during
dry and wet climatic periods in order to evaluate the extent of point and
non-point source contamination. A program of groundwater sampling was also
conducted within Sea Pines in order to obtain additional data. These studies
confirmed the existence and magnitude of non-point contamination of Lawton
Creek. However, exact sources of the non-point problem were unable to be
identified. Only the effluent from the Sea Pines treatment olant met water
quality standards with any consistency.
Additional non-point work is now underway through the 208 program The
firm of Moore Gardner § Associates is performing the work under the direction
of an advisory committee representing local, state, and Federal governments
1-3
-------
The focus of the study is to develop effective management practice which will
abate non-point pollution from island developments. Conclusions from this
work will serve as an adjunct to the findings of this EIS regarding wastewater
management.
1-4
-------
CHAPTER II
ALTERNATIVES DEVELOPMENT AND EVALUATION
-------
-------
CHAPTER II - ALTERNATIVES DEVELOPMENT AND EVALUATION
PART A. INTRODUCTION
The purpose of this chapter is to provide a systematic development of
all reasonable wastewater management alternatives which will adequately
handle the wastewater flows projected for the year 2000 from Hilton Head
Island. These alternatives are evaluated and compared so that critical
differences between them can be identified. Alternatives are developed for
each PSD area and for non-PSD areas.
This chapter presents a range of structural engineering alternatives and
nonstructural considerations for the solution of wastewater management prob-
lems on the island. These alternatives are evaluated with respect to
capital and operational costs, system operability, and implementability.
Environmental consequences are presented in Chapter III.
Because the major wastewater management consideration affecting Hilton
Head Island is the disposal and/or beneficial utilization of treated waste-
water the structural alternatives primarily focus on the available methods
of effluent disposal. These methods generally include golf course irriga-
tion, discharge to surface waters, land application other than golf course
irrigation, and discharge to wetlands.
Non-structural wastewater considerations discussed include optimizing
the use of existing facilities, flow and waste reduction measures, land use
and development controls, and the control of non-point source pollution.
A no-action alternative is also presented for each of the service areas
This alternative represents the option to provide no Federal (EPA) funding
toward the construction of expanded wastewater treatment capacity on Hilton
Head Island. Because local and/or private funding of wastewater facilities
is not precluded under this alternative, no-action does not necessarily
imply no growth for Hilton Head Island.
PART B. POPULATION AND WASTEWATER FLOW PROJECTIONS
The wastewater flows which will be generated in the year 2000 are a
function of the population projected for Hilton Head Island, the extent of
sewer services, and the per capita water use. In order to forecast wastewater
flows for the year 2000 for each of the public service districts and Hilton
Head Plantation, each of these factors is evaluated separately and then
combined for each service district.
II-l
-------
1. POPULATION PROJECTION
As detailed in Chapter III, population projections have been made from
both the OBERS and JPC base and disaggregated among the public service dis-
tricts the Hilton Head Plantation, and the areas of the island outside
of the existing PSD boundaries. Tables III-l and III-2 present the dis-
aggregation of the year 2000 JPC and OBERS base population respectively.
These population figures represent the maximum monthly average population
during the year, based upon historical occupancy rates for rental units and
seasonal residents.
2. PERCENT SEWERED
The percent of the year 2000 population which will be served by central
wastewater collection and treatment facilities is dependent upon the proximity
of sewers, the availability of adequate wastewater treatment and disposal
capacity, and the suitability of soils for the use of on-lot systems. In
order to establish the maximum needs for the treatment and disposal capacity
for existing service areas, it is assumed that the existing PSD areas and the
Hilton Head Plantation will be 100 percent sewered by the year 2000 This
assumption is made to assure that planning considers fully adequate facilities
and that worst case environmental impacts can be evaluated. However it is
not intended to preclude the use of existing on-lot systems that are function-
ing properly or the use of on-lot systems for new construction where soils
are suitable.
5. PER CAPITA WASTEWATER FLOWS
Little data exist regarding the actual per capita wastewater flows that
are generated on Hilton Head Island. Available data presented in the 201
Facilities Plan and more recent studies performed for several of the PbD s
have been reviewed. Because large quantities of potable water are used for
irrigation purposes, there is little correlation between metered potable
water usage and the quantity of spent water that is returned back to the
sewers.
The South Carolina DHEC, in Pamphlet WDG-4, presents guidelines for
unit contributory loadings to wastewater treatment plants. Design loadings
are based primarily upon a rate of 100 gallons per capita per day (gpcd).
In the absence of more substantive data, this rate is used as a basis for
initial wastewater flow projections for Hilton Head.
The wastewater generated by the resident and seasonal population of
Hilton Head is taken as 100 gpcd. This rate includes an allowance for non-
excessive infiltration/inflow. Wastewater generated by overnight visitors
to Hilton Head Island is also taken as 100 gpcd. This rate accounts for
lodging, dining, and entertainment activities as well as an allowance for
non-excessive infiltration/inflow.
II-2
-------
The wastewater generated by off-island employees and by visitors to
the island who do not stay overnight is estimated at 50 gpcd. This accounts
for their island activities as well as an allowance for non-excessive
infiltration/inflow.
4. SUMMARY OF WASTEWATER FLOWS FOR YEAR 2000
Based upon the population disaggregations for the year 2000, the assump-
tion of 100 percent sewer service, and the per capita wastewater flow rates
for each of the population components, wastewater flows have been projected
for each of the PSD's, the Hilton Head Plantation, and the non-PSD areas of
the island. These flow projections are summarized in Table II-l. They represent
the daily flow of the highest monthly average flow to be expected in the year
2000 based upon historical occupancy rates for rental units and seasonal resi-
dents .
It should be noted that the flow projections presented in Table II-l
are less than those projected by the individual PSD's. The differences between
the flow projections, and their impact on the selected wastewater management
alternative for each PSD, are discussed later in this chapter.
PART C. IDENTIFICATION OF AVAILABLE DISPOSAL METHODS
This section identifies and evaluates various disposal methods which
have been considered for use on Hilton Head including: treatment and land
application by slow rate irrigation, rapid infiltration, and overland flow;
treatment and discharge to Lawton Canal, Calibogue Sound, Port Royal Sound,
or the Atlantic Ocean; treatment and wetlands discharge; and on-lot systems.
1. TREATMENT AND LAND APPLICATION
Pre-treated wastewater can be applied to the land in order to provide
further treatment or to eliminate a direct discharge of effluent to surface
waters. Treatment is provided by natural processes as the applied wastewater
moves through the natural filter provided by the soil, plants, and related
ecosystem. Part of the wastewater is lost by evapotranspiration, while
the remainder returns to the hydrologic cycle through run-off or via the
groundwater system.
The three principal processes of land application of wastewater are
spray irrigation, rapid infiltration, and overland flow. All three methods
require the prior treatment of wastewater to levels adequate to protect
public health, preclude odor problems, and prevent clogging of soils or the
distribution system due to excessive solids.
II-3
-------
TABLE II-l
WASTEWATER FLOW PROJECTIONS
FOR YEAR 2000, IN GPD (1)
Area
Sea Pines PSD
Forest Beach PSD
Broad Creek PSD
Hilton Head No. 1 PSD
Hilton Head Plantation
Long Cove Club
Non PSD Areas
TOTAL
OBERS
1,722,800
1,129,200
638,600
620,300
308,700
106,300
258,650
4,784,550
JPC
1,977,150
1,385,050
807,450
764,900
438,350
141,150
345,700
5,859,750
(1) Daily flows based on highest monthly average flow during
maximum summer visitor occupancy.
II-4
-------
Golf course irrigation using treated wastewater serves as the basis
for wastewater management systems on Hilton Head. The ability of the golf
courses to utilize all of the treated effluent which will be generated by
the projected year 2000 peak population varies within each PSD, and as a
result, supplemental methods for effluent disposal may be required.
Irrigation (Slow Rate)
Irrigation is the predominant land application technique in use today.
It involves the application of pre-treated wastewater onto the land either'
by sprinkler or by surface flooding in order to support plant growth. Waste-
water is applied at rates between 0.5 and 4 inches per week; the applied
wastewater is absorbed by plant uptake, lost to the air by evapotranspiration,
and absorbed into the groundwater by percolation. Wastewater which percolates
through the soil matrix is renovated by physical, chemical, and biological
processes. A well-drained soil is preferred. In general, soils ranging from
loose clays to sandy loams are suitable.
Slow rate irrigation is generally capable of producing the best results
of the land treatment systems. Organics are substantially reduced by biologi-
cal oxidation within the top few inches of the soil. Suspended solids and
fecal coliform are filtered as the wastewater passes through the soil matrix.
Nitrogen is primarily removed by vegetative uptake; phosphorus is removed
from solution by fixation processes in the soil and by vegetative uptake.
To date, spray irrigation has been the method of choice on Hilton Head
Island. The systems on Hilton Head have involved the spraying of secondary-
treated wastewater onto golf courses and onto other areas specifically
designated for receiving wastewater effluent. The long-term commitment of
undeveloped open lands on the island to serve as dedicated spray areas could
be utilized to supplement the continued irrigation of existing and future
golf courses. The land could be cleared so that wastewater could be applied
by means of a center pivot or traveling gun system, or the land could be left
in a wooded state and wastewater applied through a solid-set distribution
system.
Rapid Infiltration (High Rate)
In rapid infiltration systems, pre-treated wastewater is applied to the
land at high rates (4 to 84 inches per week) by flooding in surface basins
or high-rate sprinkling. Renovation of the applied wastewater occurs as it
passes through the soil matrix. The renovated wastewater can be used for
(1) groundwater recharge, (2) natural treatment followed by recovery of the
percolated wastewater through pumped withdrawal or collection by underdrains,
(3) natural treatment with renovated waters moving vertically and laterally
through the soil and recharging nearby surface waters, or (4) temporary
storage in the aquifer.
II-5
-------
Soils with infiltration rates of 4 inches to 2 feet per day are re-
quired for a successful rapid infiltration system. The depth to ground-
water should be at least 10 feet. Acceptable soil types include sands,
sandy loams, loamy sands, and gravel. Renovation of the applied waste-
water results from the filtering and straining action of the soil matrix.
Suspended solids, BOD, and fecal coliforms are almost completely removed
in most cases. Nitrogen removal is generally poor unless specific operating
procedures are established to maximize denitrification.
Other important considerations for a rapid infiltration system in-
clude percolation rates; depth, movement, and desired quality of the ground-
water; topography; and underlying geologic formations. Subsoil and aquifer
characteristics must be known in order to control the wastewater after it
infiltrates the surface and percolates through the soil matrix. Recharge
should not be attempted without specific knowledge of the movement of the
water in the soil system and the groundwater aquifer.
A major constraint for using rapid infiltration on Hilton Head is the
growing concern that the island is a recharge area for the principal artesian
aquifer. This aquifer serves as the primary source of water for users on
the island. Because rapid infiltration does not remove nitrogen from applied
wastewater as completely as other land application techniques, there is concern
that nitrates could enter the principal artesian aquifer. Consequently,
further detailed studies would be needed and appropriate special precautions
could be required for any full-scale rapid infiltration system located on
the island.
Overland Flow
Overland flow involves the application of pre-treated wastewater over
the upper reaches of sloped terraces. The applied wastewater is allowed to
flow across the vegetated surface to runoff collection ditches. As the
wastewater flows down the slope in a thin sheet, it is renovated by physical,
chemical, and biological processes. The collected wastewater may either be
discharged to surface waters or recycled back to the land.
Clayey soils with limited drainability are suited for an overland flow
system. The land should have a slope between 2 to 8 percent and a smooth
surface without ridges and depressions so that the wastewater will flow in
a thin sheet over the ground surface. Conditions on Hilton Head Island
are generally not favorable for the use of overland flow as a land application
technique. Sandy soils predominate on the island, and extensive grading
would be necessary to develop an application site with slopes between 2 and
8 percent as required for an overland flow system.
II-6
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2. TREATMENT AND DISCHARGE
Another alternative for the disposal of wastewater involves treatment
and discharge to surface waters. The level of treatment must be adequate
to meet established water quality standards. A minimum of secondary treat-
ment is required by the U. S. Environmental Protection Agency (30 mg/1* each
for BOD5 and suspended solids). Additional treatment may be required depending
upon uses of the receiving stream and its ability to take the waste without
violating water quality standards (assimilative capacity). Waters surrounding
Hilton Head include the near-shore waters of Lawton Canal, Lawton Creek, and
Broad Creek and the off-shore waters of Calibogue Sound, Port Royal Sound,
and the Atlantic Ocean. These waters are shown in Plate II-l. The South
Carolina DHEC has set forth treatment requirements for discharges into these
waters based upon their assimilative capacity. These requirements are pre-
sented in Table I1-2. A secondary level of treatment is indicated for Calibogue
and Port Royal Sounds; a higher level of treatment (lower numerical effluent
limits) is required for a discharge into the Lawton Creek complex.
An additional consideration for any discharge to the surface waters
surrounding Hilton Head is their classification for shellfishing. Under the
requirements of the National Shellfish Sanitation Program (NSSP) Manual of
Operations, the discharge of treated wastewater to shellfish waters requires
a buffer zone around the discharge point from which the harvesting of shell-
fish is prohibited. The purpose of the buffer zone is twofold: (1) to
ensure that public health is protected by preventing contamination of shell-
fish waters by disease-causing organisms (pathogens) from normally operating
treatment works, and (2) to provide time for notification to cease harvesting
in the shellfish growing waters beyond the buffer zone following a malfunction
of the wastewater treatment facility.
The buffer zone for the present Sea Pines PSD discharge to Lawton Canal
includes all of Lawton Creek to its confluence with Broad Creek and the adjacent
shore of Broad Creek generally opposite Buck Island. According to a Food and
Drug Administration report (December 1978), this buffer zone would be extended
to just above Harbour Town Marina to the south and to the northern tip of Buck
Island to the north for the full width of Broad Creek for a discharge of 4.0
mgd from the Sea Pines Plant. Plate II-l depicts the existing and proposed
buffer zones as described above.
A discharge through an underwater outfall and diffuser into either Cali-
bogue Sound, Port Royal Sound, or the Atlantic Ocean is not anticipated
to result in the closure of shellfish beds. Detailed studies would be needed
to determine the optimal location and orientation of the diffuser structure
to ensure maximum mixing and dispersion of the effluent and thereby minimize
adverse impacts on water quality.
*mg/l - milligrams per liter approximately equivalent to one part by weight
of material in 1,000,000 parts of water.
II-7
-------
Receiving Stream Discharge Flow
Lawton Canal
Calibogue Sound
Port Royal Sound
Atlantic Ocean
TABLE 11-2
EFFLUENT REQUIREMENTS FOR
DISCHARGES TO SURFACE WATERS(1)
BODc
3.0 mgd
3.0 mgd
1.0 mgd
3.0 mgd
10 mg/1
30 mg/1
30 mg/1
30 mg/1
NHz-N
1.5 mg/1
Suspended Solids
15 mg/1
30 mg/1
30 mg/1
30 mg/1
Ultimate Oxygen Demand
Total Allowable
546 Ibs/d
3,378 Ibs/d 9,000 Ibs/d
1,126 Ibs/d 28,000 Ibs/d
3,378 Ibs/d
I
00
(1) Based upon determinations by South Carolina Department of Health and Environmental Control.
See Appendix C for letter.
-------
5. TREATMENT AND WETLANDS DISCHARGE
The term wetlands is a broad classification covering areas known as
marshes, bogs, wet meadows, peatlands, and swamps. They generally consist
of low-lying, usually level, saturated land which is partially or inter-
mittently covered with standing water. In wetland discharge systems, waste-
water is renovated by the soil, plants, and microorganisms as it moves through
the soil profile. However, renovation action is usually more dependent on
microbial and plant activity than on soil chemistry. The ability of wetlands
to influence water quality has precipitated much current research into their
use for wastewater management. Both artificial and existing wetlands have
been studied, using untreated as well as secondary effluents.
Tidal marshes occupy a significant area of Hilton Head Island; however
their proximity to areas which are suitable for shellfishing preclude their'
consideration as a part of a controlled wastewater management system Fresh-
water marsh and freshwater swamp forest areas also exist on the island The
Nancy Cathcart Chapter of the Sierra Club has endorsed discharging a portion
of the treated effluent from Sea Pines PSD - Forest Beach PSD into drainage-
ways of the Sea Pines Forest Preserve as a means to restore the area's wet-
lands Periods of drought and diversion of natural recharge into the Preserve
have dried up many wetlands areas within the Preserve thereby drastically
altering the natural habitat. The South Carolina DHEC and the South Carolina
Coastal Council have both approved this concept on an experimental basis
Ine design of the system is now in preparation.
Cypress Swamp and Whooping Crane Pond areas in Hilton Head Plantation
are also affected by periodic drought conditions. Both of these areas serve
as bird rookeries and as the habitat for numerous wildlife species. Cypress
Swamp contains the only stand of bald cypress on the Sea Islands, while
Whooping Crane Pond is the only swamp area in lower South Carolina that
combines mature tupelo trees with open water. A proposal from the Hilton
Head Plantation Utility Company to utilize treated wastewater to revive the
Cypress Swamp Conservancy is now under consideration by DHEC.
4. SYSTEMS FOR UNSEWERED AREAS
The majority of the areas which lie outside the boundaries of the Hilton
Head Plantation or the existing PSD's utilize septic tank-drainfield systems.
Wastewater management for these areas may take one of several forms de-
pendent upon whether existing septic tank systems are functioning properly.
Individual Systems
pvnp C°nVenti?nal S6PtiC tank-drainfield systems are the simplest and least
expensive on-lot systems, if properly sited and maintained. Existing septic
II-9
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tank systems that are functioning properly will continue to be used in the
non-PSD areas; where soils are suitable, the use of septic tank-drainfield
systems are envisioned for new construction. Where septic tank failures
occur on an isolated basis, improvements would be made to the individual home.
The DHEC Bureau of Environmental Sanitation acts upon all septic tank
applications for individual residences. Applications for larger systems
(greater than 1,500 gpd) are reviewed by the Bureau of Wastewater and Stream
Quality Control of DHEC. Site evaluations are conducted by DHEC for every
site for which application has been made for installation of a septic system.
Consideration is given to soil texture; depth to groundwater; and distances
from wells, ditches, bodies of water, and property lines. The minimum
allowable depth to groundwater is 36 inches; modification of the site through
grading and filling may be used to achieve this minimum separation on a case-
by-case basis. Recommended minimum lot sizes are 12,500 square feet for
homes served by a community water system and 30,000 square feet where water
is provided by an on-site well.
The soils on Hilton Head Island are generally poorly drained, moderately
permeable sands, loamy fine sands, and sandy loams. Fifteen general soils
series have been identified on Hilton Head; these determinations have been
made on-site by soil scientists of the Soil Conservation Service (SCS), U. S.
Department of Agriculture.
Of the fifteen soil series, only the Wando series has been given a
"slight" classification by the SCS. (Other soil series have been given
"severe" classifications primarily due to seasonally high groundwater). A
"slight" classification usually means that any soil limitations are minor
and easily overcome and that septic tanks should work properly when ade-
quately sized, correctly installed, and regularly maintained. Plate 11-2
shows the location and extent of the Wando series on Hilton Head. As shown,
there are large areas of the Wando series along Route 278 from approximately
Palmetto Dunes to Sea Pines Circle, in the Matthews Drive - Port Royal area,
between Route 278 and Marshland Road, and north and west of the Hilton Head
Airport.
Other areas of the island may be suitable for septic tank systems, or
be made suitable by moderate site improvements such as grading or filling.
Such areas, however, must be determined based upon a site survey on a lot-
to-lot basis If soil limitations are severe, use of modified septic tank/
soil absorption systems may sometimes be used. Site modifications may include
grading or filling, or both; absorption system modifications may include con-
structing subsurface sand filters or elevated sand mounds.
Elevated sand mounds are used in conjunction with septic tanks. The
elevated sand mound is simply a mound of sandy fill material which is placed
on the surface of the ground. The sandy fill serves as a physical and
biological medium in which the septic tank effluent is filtered before being
absorbed by the natural soil. In cases of failing systems, an elevated sand
mound would replace the existing sub-surface drainfield. Use of an elevated
sand mound would require that effluent from the septic tank be pumped to the
mound for disposal.
11-10
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Community Systems
The community approach to wastewate.r management involves the collection,
treatment, and disposal of sewage from a number of homes. Community systems'
would be utilized where septic tank failures occur on a widespread basis
where soils in a general area are unsuitable, or in areas of higher popu-
lation density.
There are several candidate alternatives for community systems which
could prove effective for the non-PSD areas. These alternatives are discussed
below.
Community Sand Mound - Where failing septic tank systems exist at a number
of homes within a small area, a community sand mound system could be utilized
A community sand mound is used in conjunction with the septic tanks at each
home. Wastewater is pumped from each septic tank to the community mound
system for application. The mound must provide an adequate amount of un-
saturated soil and spread the septic tank effluent over a sufficient area so
that distribution and purification can occur before the water table is reached.
Package Plants - A second alternative available for the non-PSD areas involves
the construction of a package wastewater treatment plant to handle flows from
the community. Spray irrigation of treated effluent would likely be required
because of inadequate receiving streams available for discharge.
Conveyance to PSD - Wastewater may be conveyed from the community to an
existing PSD for treatment and disposal. A pumping station and force main
are required for this alternative.
PART D. NON-STRUCTURAL WASTEWATER MANAGEMENT CONSIDERATIONS
Effective and functional non-structural control mechanisms for waste-
water management can be an important adjunct to the construction of waste-
water collection and treatment facilities. Non-structural considerations in-
clude a variety of regulatory, administrative, and educational procedures
which can be used to supplement structural water quality control techniques
The application of non-structural methods may provide a means for lessening
the magnitude of structural facilities required for attainment and maintenance
of water quality standards. Therefore, the principal focus of non-structural
alternatives is their use in supporting and supplementing structural alterna-
tives and solutions. Non-structural alternatives typically require widespread
community support but are also typically less expensive than structural alterna-
tives.
11-11
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1. OPTIMUM USE OF EXISTING WASTEWATER FACILITIES
Very often, wastewater treatment facilities do not perform at their
designed efficiency. No matter how well planned, how well designed, or how
well constructed, provisions must be made for the proper operation and mainte-
nance of wastewater facilities. The objective of efficient operation and
maintenance is to continuously meet the effluent quality performance limits
required by state permits, to make plant operations as economical as possible
consistent with meeting the required effluent limits, and to reduce the need
for repair and replacement of mechanical and electrical equipment at the
plant.
A well trained staff is required to ensure good plant operation and
maintenance. For the most part, wastewater treatment facilities on Hilton
Head appear to be adequately operated and maintained; efforts should be made
to provide continued training for the operators. One facility wherein in-
adequate program of operation and maintenance has existed is the Mariner's
Cove treatment plant which serves about forty units of the Mariner's Cove
Complex. During the period from approximately May 1979 through September
1979 the Mariner's Cove system was either out of operation or operating
marginally. As a result of equipment failures, raw or inadequately treated
wastewater was intermittently discharged to Skull Creek. This occurrence
emphasizes the often overlooked need to provide regular operation and
maintenance at smaller wastewater facilities.
2. FLOW AND WASTE REDUCTION MEASURES
Another non-structural technique that can be employed in wastewater
management is the use of water conservation and flow reduction techniques.
Benefits can include reduced water supply demand, reduced treatment operating
costs, relieving overloaded wastewater treatment and disposal facilities,
and reduced capital cost and capacity required for new facilities.
Several non-structural measures are available for use in the Hilton
Head study area to reduce future water use and wastewater flow. They include
plumbing codes, building permits to enforce certain construction practices,
flow control devices, and educational programs. Water and wastewater pricing
can sometimes be effective toward reducing water consumption and, hence,
wastewater flows. However, water and wastewater pricing do not appear to be a
particularly effective technique for reducing wastewater flows on Hilton Head.
Use of indoor water-saving devices can reduce wastewater flows. Numerous
water-saving devices have been manufactured for all water-using appliances or
fixtures in the home. Use of these devices can be expected to have^a greater
impact on the growth areas of Hilton Head due to the ease with which they can
be installed in new residential units. Table II-3 presents a listing of
typical water-saving devices and potential water savings.
11-12
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TABLE II-3
SUMMARY OF INDOOR RESIDENTIAL WATER-SAVING DEVICES
Device
Toilet Alteration
Displacement Device
Toilet Dam
Shallow-Trap Toilet
Dual-Cycle Toilet
(Toilet Flush Adaptor)
Without Alteration
Shower Alteration
Flow Control Devices
Aerators
Automatic Shut-Off Valves
Without Alteration
Faucet Alteration
Flow Control Devices
Expected Water Savings
Water Use
(gal/flush or unit Percent of Total
gal/nunute) Igpcpd) Household Use
- 9 Q A f\
*•• •> 4.0
5.5 8.0-20.0
3-S 7.5-12.5 11.0-18.0
1.25-2. SO 17.5-25.0 25.0-36.0
5.0-7.0
2.5-3.5 6.3-9.5 9.0-13.6
1-5-3.0 7.0-10.0 10.0-14.0
"• a t\ f\ f\
6.0 9.0
S. 0-7.0
0.5-2.5 n.5 n a_i f.
Average Cost
to Install
($)
0-6
1-6
13-75
4-14 (Device)
0-65 (New Tank)
1-7
1-5
0-2
Aerators.
Spray Taps
Without Alteration
2.0-3.5
1.0-2.0
S.0-6.0
0.5
0.75
0.8-1.5
2.0
1-5 (Modification)
10-30 (New)
1-2
20-50 (New)
-------
The Beaufort County Plumbing Code is based upon the Southern Standard
Plumbing Code, 1979 edition. The regulations in the code do not require
the use of water-saving devices, such as those described above. The County
may wish to consider amendment of the plumbing code to require the use of
water saving devices in all new construction.
5. LAND USE AND DEVELOPMENT CONTROLS
Increases in Hilton Head's resident and tourist population has had and
will continue to have significant impacts on wastewater management. As popu-
lation increases, vacant land is converted to an assortment of uses such as
residential and commercial development and street and highway uses. This
can generate increased storm runoff which may significantly degrade surface
water quality depending on the type and location of development. In addition,
wastewaters generated by new development must be assimilated by a limited land
and water system.
Land development controls are an important aspect of water quality manage-
ment planning. Land use regulations can be used to direct development away
from sensitive environmental areas, including water quality sensitive areas.
Land use controls can also serve to mitigate any short-term or long-term
negative impacts that may result from the provision of wastewater treatment
and disposal facilities.
Act 487 of South Carolina Acts of 1967 gives counties and municipalities
the authority to establish planning commissions and prepare comprehensive
plans for their jurisdictions. The Beaufort Joint Planning Commission_was
established in February 1969 and has the power to plat land, enact zoning
ordinances, and provide other development controls in Beaufort County and
its municipalities. Because Beaufort County has enacted no zoning ordinance,
the major piece of legislation affecting development on Hilton Head Island
is the Beaufort County Development Standards Ordinance (DSO), which was adopted
in the fall of 1978. It replaced the Beaufort County Subdivision Regulations,
which had been adopted in 1974. The DSO is not a zoning ordinance, but in-
stead sets forth minimum construction standards and site design criteria which
must be met before land can be developed. The ordinance addresses_performance
standards for setbacks; streets; rights of way and pavements; parking and
loading; provision of utilities, drainage, planning and design certification;
preservation of vegetation; erosion control; pollution and nuisance control;
and open space provisions.
The DSO is no longer adequate to solve the problems created by the
ongoing development of Hilton Head Island, and Beaufort County officials
recognize that additional development controls are needed. As a first step
in arriving at the form which such controls should take, the Beaufort County
Joint Planning Commission (JPC) has almost completed work on the preparation
of a comprehensive land use plan for Hilton Head Island. The plan is in-
tended to serve as a policy statement about future development and distri-
bution Upon completion of the land use plan, County Council will consider
available mechanisms which can be used to control and direct growth on Hilton
Head.
11-14
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4. NON-POINT SOURCE POLLUTION
As previously indicated in Chapter I, the control of non-point source
pollution on Hilton Head is of increasing importance as development continues.
Water quality studies have determined that the bacterial degradation of
Lawton Creek is attributable to non-point source runoff. Few data are avail-
able to indicate the present quality of inland waters of the northern portion
of the island, but it is expected that they are also susceptible to non-
point runoff unless effective control programs are implemented commensurate
with development.
A cooperative venture is now underway between the EPA, DHEC, and Beaufort
County to develop management practices which can be implemented on Hilton
Head to control non-point source pollution. This work is being funded through
the Section 208 program.
The study will focus on identification of drainage patterns on the island,
water quality sampling, and the control of stormwater runoff. Recommendations
from this program regarding the control of non-point source pollution must be
integrated with the wastewater management programs on the island in order to
upgrade and preserve the quality of area waters.
PART E. WASTEWATER MANAGEMENT ALTERNATIVES
Wastewater management alternatives are presented and evaluated in this
section for each of the PSD's on Hilton Head. In addition, wastewater manage-
ment alternatives are presented for the Hilton Head Plantation and the non-
PSD areas of the island.
1. SEA PINES PSD - FOREST BEACH PSD
The Sea Pines PSD treatment plant is owned and operated by the Sea Pines
Public Service District Commission. The plant treats wastewater generated from
the Sea Pines PSD and the Forest Beach PSD. The plant has an existing capacity
of 2.5 million gallons per day (mgd). A portion of the treated effluent is
spray irrigated onto the Club Course, the Hilton Head Golf Club, or portions of
the Forest Preserve. The remainder is discharged into Lawton Canal.
11-15
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At the request of the Sea Pines PSD, the South Carolina DHEC has modi-
fied Consent Order 78-84-W, as amended on December 19, 1978 to permit in-
fluent flow to the plant up to 3.25 mgd and to reduce the allowable discharge
to Lawton Canal to 1.8 mgd. Previously, this Consent Order restricted flow
to the plant to 2.5 mgd and limited the allowable discharge to Lawton Canal
to 2.0 mgd.
The Sea Pines PSD will modify their existing treatment facilities to
provide a 3.25 mgd capacity. The construction required is considered as
the first phase of the PSD's ultimate plans to expand plant capacity to 5.0
mgd to meet projected needs of Sea Pines and Forest Beach. The PSD plans
to irrigate the remaining three golf courses (Ocean, Sea Marsh, and Harbour
Town) in Sea Pines with treated wastewater. In addition, an experimental
wetlands discharge system will be implemented in the Sea Pines Forest Pre-
serve. This system, conceived by conservationist Todd Ballentine and en-
dorsed by the Nancy Cathcart Chapter of the Sierra Club, will involve the
discharge of treated effluent into drainageways of the Sea Pines Forest
Preserve as a means to restore the area's wetlands. The irrigation of all
five golf courses and the wetlands experimental system, coupled with the
allowable 1.8 mgd discharge into Lawton Canal, are judged to be sufficient
to fully accommodate the 3.25 mgd capacity of the expanded Sea Pines PSD plant.
Projected Wastewater Flows
As previously indicated, OBERS- and JPC-based populations have been
projected for the year 2000 for each service area of Hilton Head Island.
Wastewater flows for the year 2000 are based upon the "peak month" popula-
tion and per capita flow rates for each of the population components.
Peak monthly average flows for the year 2000 for Sea Pines PSD - Forest
Beach PSD are 2.85 mgd (based upon OBERS) and 3.36 mgd (based upon JPC).
By comparison, the Sea Pines PSD plans to expand its wastewater treatment
facilities to an ultimate capacity of 5.0 mgd. Part of this difference can
be attributed to consideration of occupancy rates. When the JPC-based year
2000, peak month population is adjusted to reflect 100 percent occupancy,
a corresponding wastewater flow of 4.22 mgd results.
Description of Alternatives
Wastewater management alternatives have been formulated for Sea Pines
PSD-Forest Beach PSD. Each alternative includes the 3.25 mgd Sea Pines PSD
plant, irrigation of the five golf courses, and the experimental wetlands
system.
Even with irrigation of all five golf courses, a substantial amount of
wastewater will remain which must be handled by supplemental means. Analyses
have previously been conducted of the seasonal irrigation needs of these courses
11-16
-------
as part of this Environmental Impact Statement. Figure II-l shows the monthly
average wastewater flows projected for the year 2000 (JPC) versus the estimated
seasonal golf course usage. Table II-4 presents the difference between waste-
water flows and golf course irrigation quantities on a monthly average basis
for both the year 2000 JPC and OBERS flows.
Supplemental disposal techniques include advanced treatment and discharge
to Lawton Canal, secondary treatment and discharge to Calibogue Sound via a
subaqueous outfall and diffuser, and treatment and land application either on
or off the island.
Secondary treatment and discharge to the Atlantic Ocean was eliminated
from further consideration based upon comparison with the Calibogue Sound
alternative. The costs for an outfall to the Atlantic Ocean are substantially
greater than for an outfall to Calibogue Sound because of the relative depths
of the water bodies at equal distances off-shore. Water of greater than 30-foot
depth could be reached in Calibogue Sound with an underwater outfall approxi-
mately 4,000 feet long; to reach even a 20-foot depth in the Ocean would re-
quire an outfall over 15,000 feet in length and to reach a 30-foot depth would
require an outfall over 26,000 feet in length. Figure II-2 shows this dif-
ference in depths very vividly. Because of the longer underwater outfall that
would be required, a discharge to the Atlantic Ocean would cost approximately
two to three times that for a discharge to Calibogue Sound. In addition, the
Atlantic Ocean does not offer any advantages over Calibogue Sound as a point
of discharge based upon its ability to receive and assimilate wastewater.
The land application schemes have been developed following the evaluation
of undeveloped parcels on Hilton Head both within, and outside of, the ex-
isting boundaries of the Sea Pines PSD and the Forest Beach PSD. One scheme
has been formulated to meet the possible constraint that lands outside the
PSD boundaries cannot be obtained for the land application of wastewater;
the other considers that land outside the PSD boundaries can be obtained.
In addition, land application at a site off the island has also been con-
sidered.
Descriptions of each alternative are provided in the following sections.
Lawton Canal Discharge - This alternative involves the discharge of advanced-
treated wastewater to Lawton Canal as a supplement to irrigation of the five
golf courses. Sand filters would be constructed at the 3.25 mgd plant pro-
posed by the Sea Pines PSD in order to achieve the effluent quality required
by DHEC. The experimental wetlands discharge system would be utilized to
the extent possible as a back-up system. Figure II-3 provides a schematic
representation of this alternative.
Calibogue Sound Discharge - This alternative involves the discharge of
secondary-treated wastewater to Calibogue Sound through a subaqueous outfall
and diffuser as a supplement to irrigation of the five golf courses. Again,
the experimental wetlands discharge system would be utilized to the extent
possible as a back-up system. Figure II-4 presents a schematic representation
of this alternative.
11-17
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-------
-n
WASTE WATER FLOW OR
SPRAY IRRIGATION RATE (IN MGD)
o
c/) >
CD Z
m m
> co
m
31
O H
z m
^
o
> -n
> o
•°? s*
CO ' j ^
o K <
m
m
-------
TABLE II-4
WASTEWATER IN EXCESS
OF GOLF COURSE IRRIGATION NEEDS
FOR SEA PINES PSD - FOREST BEACH PSD, in mgd
Month
January
February
March
April
May
June
July
August
September
October
November
December
OBERS
1.23
1.15
1.32
1.34
1.01
1.03
2.03
2.04
1.04
1.32
1.28
1.35
JPC
1.47
1.37
1.61
1.66
1.34
1.44
2.51
2.55
1.38
1.63
1.56
1.63
11-18
-------
N
10 26
16 31
WATER DEPTHS OF
CAUBOGUE SOUND AND
ATLANTIC OCEAN
FIGURE H-2
-------
DISCHARGE TO
LAWTON CANAL
t
CLUB GOLF
COURSE
A
SAND
FILTERS
SEA PINES PSD
TREATMENT
PLANT
A
HILTON HEAD
GOLF CLUB
SEA MARSH
GOLF COURSE
EXPERIMENTAL
WETLANDS
DISCHARGE
HARBOUR TOWN
GOLF LINKS
OCEAN GOLF
COURSE
A
LEGEND
PROPOSED SAND FILTERS
GOLF COURSE
IRRIGATION
PROPOSED EXPERIMENTAL
WETLANDS DISCHARGE
— PROPOSED DISCHARGE
LAWTON CANAL
DISCHARGE
SEA PINES PSD-
FOREST BEACH PSD
FIGURE n-3
-------
DISCHARGE TO
CALIBOGUE SOUND
t
CLUB GOLF
COURSE
SEA PINES PSD
TREATMENT
PLANT
HILTON HEAD
GOLF CLUB
SEA MARSH
GOLF COURSE
EXPERIMENTAL
WETLANDS
DISCHARGE
HARBOUR TOWN
GOLF LINKS
OCEAN GOLF
COURSE
A
LEGEND
GOLF COURSE
IRRIGATION
PROPOSED EXPERIMENTAL
WETLANDS DISCHARGE
PROPOSED OUTFALL
CALIBOGUE SOUND
DISCHARGE
SEA PINES PSD-
FOREST BEACH PSD
FIGURE H-4
-------
-------
The outfall to Calibogue Sound would be routed from the Sea Pines plant
southward along Sea Pines Drive and then across South Beach. Detailed
studies would be necessary to determine the optimal location and orientation
of the diffuser in order to ensure maximum mixing and dispersion of the
effluent.
Rapid Infiltration - This alternative utilizes a combination of rapid infil-
tration, woodlands irrigation, and wetlands discharge within the Forest Preserve
to provide for the complete disposal of the wastewater quantities which are
not used by the five golf courses. Figure II-5 provides a schematic representa-
tion of this alternative.
Table I1-5 presents the amount of wastewater which must be handled by
each of the disposal techniques in order to provide a workable alternative.
If either wetlands discharge or rapid infiltration cannot reliably handle
the indicated rate of application, then the other must accommodate the dif-
ference. If both wetlands discharge and rapid infiltration cannot reliably
handle their respective rates of application, there is insufficient suitable
land within the PSD's for woodlands irrigation to take up the slack.
The woodlands irrigation scheme involves the application of treated
wastewater onto wooded parcels which lie within the Forest Beach PSD along
its boundary with the Broad Creek PSD and immediately adjacent to the Hilton
Head Golf Club. These parcels have an estimated usable area of approximately
32 acres. At an application rate of 2 inches per week, approximately 0.25
mgd could be applied. A solid-set spray irrigation system would be used
to apply wastewater to these woodland areas in order to reduce alteration of
the natural habitat. Wastewater would be pumped to the sites from the Sea
Pines PSD plant via force main along Pope Avenue and up Route 278.
As indicated in a recent report prepared for the Sea Pines PSD, a site
within the Sea Pines Forest Preserve adjacent to the Sea Pines PSD plant is
the best site available for construction of a rapid infiltration system.
This area is presently wooded and construction of a rapid infiltration system
would require extensive clearing and site alteration. Approximately 12 acres
of bed area would be required to dispose of 1.3 mgd at an application rate
of 25 inches per week. Dual beds would be required so that application could
be alternated between the two. Because of the concerns over possible nitrate
contamination of groundwater, an intensive monitoring program would be re-
quired so that nitrogen movement and transformation through the soil pro-
file could be ascertained. Evidence of groundwater contamination would re-
quire lower application rates and/or total nitrogen removal at the Sea Pines
PSD plant.
The wetlands discharge system holds exceptional promise as a means to
dispose of treated wastewater. However, it is not possible to determine the
amount of treated wastewater which can be absorbed within the Forest Preserve
except through actual operation and monitoring of the system.
11-19
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SPRAY IRRIGATION OF
FOREST BEACH PSD PARCELS
CLUB GOLF
COURSE
SEA PINES PSD
TREATMENT
PLANT
A
HILTON HEAD
GOLF CLUB
SEA MARSH
GOLF COURSE
1.0 MGD
WETLANDS
DISCHARGE
HARBOUR TOWN
GOLF LINKS
RAPID
INFILTRATION SITE
OCEAN GOLF
COURSE
A
LEGEND
GOLF COURSE
IRRIGATION
PROPOSED SPRAY
IRRIGATION SITE
PROPOSED RAPID
INFILTRATION SITE
PROPOSED WETLANDS
DISCHARGE
RAPID INFILTRATION
ALTERNATIVE
SEA PINES PSD-
FOREST BEACH PSD
FIGURE n-5
-------
TABLE I1-5
SEA PINES PSD - FOREST BEACH PSD
LAND APPLICATION CAPACITIES FOR DISPOSAL COMPONENTS
OF RAPID INFILTRATION ALTERNATIVE
Component
Wetlands application into
Sea Pines Forest Preserve
Woodlands irrigation of
Forest Beach PSD parcels
Rapid infiltration at site
between Sea Pines PSD plant
and Waterfowl Pond in Sea
Pines Forest Preserve
Capacity in mgd
Low
1.0 CD
0.25 C2)
1.3 (4)
High
1.0 (1)
0.5 (3)
1.3 (5)
Total
2.55
2.8
CD
C2)
(3)
(4)
(5)
Must accommodate 1.0 mgd to provide workable alternative. Amount
of treated wastewater which can be absorbed within Preserve can only
be determined through actual operation and monitoring of the system
Based upon application rate of 2 inches per week.
Based upon application rate of 4 inches per week.
Based upon application rate of 25 inches per week.
Physical expansion of rapid infiltration system constrained by site
limitations. Increased capacity can be achieved only by sustained
application rates in excess of 25 inches per week.
11-20
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Spray Irrigation On-Island - This alternative provides for the disposal
of wastewater quantities which are not used by the five golf courses totally
by spray irrigation on a single large tract outside the boundaries of the
PSD's. The experimental wetlands discharge system would be utilized to the
extent possible as a back-up system. Figure II-6 provides a schematic representa-
tion of this alternative.
Of the undeveloped land parcels on Hilton Head, the Gardner-Matthews
tract (Parcel 1 on Beaufort County Tax Map 11) has been identified as most
suitable for land application of treated wastewater. This parcel has a total
area of nearly 1,000 acres; almost 40 percent of the parcel is composed of
the well-drained Wando soils which are generally located in the center of the
parcel. The Otter Hole Trailer Park and a 15-acre residential property lie
within the tract.
It is estimated that approximately 600 acres are suitable for slow-rate
irrigation. As shown in Table II-6, this available area far exceeds the land
required to irrigate the 2.55 mgd increment (based on JPC projections) from
the Sea Pines PSD and the Forest Beach PSD that cannot be handled by golf
course irrigation. This additional area would be available to accommodate
the expansion of the irrigation system should wastewater flows from Sea Pines
PSD - Forest Beach PSD exceed the JPC projections. The area could also serve
as a spray irrigation area for the other PSD's on the island (e.g., Broad
Creek PSD and Hilton Head No. 1 PSD) should their flows exceed JPC projections.
Portions of the tract peripheral to the spray areas could be utilized for
public recreation and dedicated open space.
A solid-set spray irrigation system would be used to apply wastewater to
this area in order to preserve the natural habitat. Wastewater would be
pumped from the Sea Pines PSD plant via Pope Avenue, Route 278, Matthews
Drive, and Marshland Road. A topographic and vegetative survey is required
in order to identify those portions of the parcel most suitable for irrigation.
Monitoring would be required to determine forest responses, wildlife responses
and groundwater impacts from the system.
Spray Irrigation Off-Island - This alternative provides for the disposal of
wastewater quantities which are not used by the five golf courses totally by
spray irrigation on large tracts of land off the island including the crossing
of Skull Creek and Mackay Creek either with an underwater pipeline or pipe
suspended from the bridges. Again, the experimental wetlands discharge system
would be utilized to the extent possible as a back-up system. Figure II-7
provides a schematic representation of this alternative.
Three general areas on the mainland have been identified as potential
spray sites, based upon soils characteristics. These areas are Union Camp
property in the Bluffton area, contiguous parcels in the Sawmill Creek area,
and contiguous parcels south of Route 278 generally across from Moss Creek
Plantation. These general areas are shown in Plate II-3.
Costs were developed for each of these off-island alternatives based
upon the purchase of land at $5,000 per acre. Using this assumption, the
costs vary within a 10 percent range dependent upon the distance of the spray
11-21
-------
SPRAY IRRIGATION OF
GARDNER-MATTHEWS TRACT
CLUB GOLF
COURSE
SEA PINES PSD
TREATMENT
PLANT
HILTON HEAD
GOLF CLUB
SEA MARSH
GOLF COURSE
EXPERIMENTAL
WETLANDS
DISCHARGE
HARBOUR TOWN
GOLF LINKS
OCEAN GOLF
COURSE
A
LEGEND
GOLF COURSE
IRRIGATION
PROPOSED SPRAY
IRRIGATION SITE
PROPOSED EXPERIMENTAL
WETLANDS DISCHARGE
SPRAY IRRIGATION
ON-ISLAND
SEA PI NES PSD -
FOREST BEACH PSD
FIGURE Tf-6
-------
-------
SPRAY IRRIGATION AT UNION CAMP
OR OTHER OFF-ISLAND SITE
CLUB GOLF
COURSE
SEA PINES PSD
TREATMENT
PLANT
HILTON HEAD
GOLF CLUB
SEA MARSH
GOLF COURSE
EXPERIMENTAL
WETLANDS
DISCHARGE
HARBOUR TOWN
GOLF LINKS
A
OCEAN GOLF
COURSE
A
LEGEND
GOLF COURSE
IRRIGATION
PROPOSED SPRAY
IRRIGATION SITE
PROPOSED EXPERIMENTAL
WETLANDS DISCHARGE
SPRAY IRRIGATION
OFF-ISLAND
SEA PI NES PSD -
FOREST BEACH PSD
FIGURE 1-7
-------
TABLE II-6
SEA PINES PSD - FOREST BEACH PSD
LAND APPLICATION CAPACITIES FOR DISPOSAL BY
ON-ISLAND SPRAY IRRIGATION ALTERNATIVE
Component
Wetlands application into
Sea Pines Forest Preserve
Woodlands irrigation of
Gardner-Matthews tract
(Parcel 11-1)
Capacity in mgd
Low
(1)
2.55 (2)
High
-- CD
5.0 (3)
Total
2.55
5.0
(1) Wetlands application will be utilized to the extent possible as a
back-up system.
(2) Based upon application rate of 2 inches per week over approxi-
mately 300 acres.
(3) Based upon application rate of 2 inches per week over entire
usable area of tract. Total usable area estimated to be
600 acres.
11-22
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site from the Sea Pines PSD treatment plant. The Union Camp site is most
costly because of its greater distance from Sea Pines; lesser land costs or
the negotiation of a cooperative, long-term arrangement with Union Camp
(with Union Camp using treated wastewater to promote timber production)
would make this site more attractive.
No-Federal Action Alternative - A requirement of the EIS process developed
by EPA is that a no-action alternative will be considered along with other
wastewater facilities alternatives. The no-action alternative implies that
no Federal funding would be available for wastewater facilities on Hilton
Head. Under this alternative, improvement and/or expansion of the wastewater
facilities would be required but there would be no Federal funds provided for
design and construction of the facilities.
In the event that EPA decides not to fund additional wastewater facili-
ties for the Sea Pines PSD - Forest Beach PSD, it is expected that expanded
treatment and disposal capacity will be provided by the private sector in
order to accommodate continued development. In fact, the planned expansion
of the Sea Pines PSD plant to 3.25 mgd, the irrigation of the Ocean, Sea
Marsh, and Harbour Town golf courses with wastewater, and the experimental
wetlands discharge system are being funded totally at the local level in
order to relieve constraints on development.
Cost Evaluation
A detailed evaluation of all significant cost components of the alterna-
tive wastewater management systems is required in order to perform the com-
parative cost analyses. Construction, project, and operation and maintenance
costs are developed for each management system for incorporation into a net
present worth cost analysis. The present worth cost analysis establishes a
basis for comparison of total costs (capital and annual operations costs)
for each of the wastewater management alternatives. These total costs include
the Federal share of the costs associated with construction grants. Com-
parative cost analysis (either present worth or equivalent annual cost) is
an EPA requirement in performing the cost effectiveness analysis and serves
as the primary cost evaluation criterion according to EPA guidelines.
Cost Development - A detailed evaluation of all significant cost components
of the alternative wastewater management systems is required in order to
perform the comparative cost analyses. Construction, project, and operation
and maintenance costs have been developed for each management system based
upon appropriate costing documents published by EPA. All costs have been
11-23
-------
trended to 1980 price levels in the Hilton Head area. Unless otherwise
noted, certain facilities have been excluded from the costing because they
are common to each of the five alternatives. These include facilities associated
with the planned expansion of the Sea Pines plant to 3.25 mgd, irrigation of
the five golf courses, and the experimental wetlands discharge system (except
for the Rapid Infiltration Alternative).
Present Worth Analysis - The present worth analysis establishes a total
cost value of the capital expenditures and operating costs of each alterna-
tive over the duration of the planning period. The present worths for the
wastewater management alternatives are developed for a 15-year planning
period ending in the year 2000 using an interest rate of 7.125 percent. In
accordance with EPA guidelines, allowances are made for salvage values at
the end of the planning period.
Tables 11-7, II-8, II-9, 11-10, and 11-11 provide cost breakdowns for
the five alternatives for Sea Pines PSD - Forest Beach PSD based upon the JPC
flows. Table 11-12 provides a comparative summary of the costs of each
alternative. As shown in the table, spray irrigation off-island at Union
Camp is approximately equal in cost to spray irrigation on-island at Gardner-
Matthews based upon purchase of land at $5,000 per acre and $15,000 per acre
respectively.
Alternatives which involve the discharge of treated wastewater into
either Lawton Canal or Calibogue Sound are substantially lower in cost than
alternatives which involve the purchase of land for a new spray irrigation
site to supplement golf course irrigation. The costs for discharge alterna-
tives range from approximately 15 to 25 percent of the costs for the land
application alternatives.
Operability Evaluation
Evaluation of operability of wastewater management alternatives should
include consideration of the following aspects:
reliability of treatment/disposal
flexibility of operation
maintainability of facilities
In the evaluation of reliability the ability of the facilities in the treat-
ment schemes to maintain the intended treatment levels is considered as well
as the reliability of the method used to dispose of the treated wastewater.
Operational flexibility is a measure of the ability of wastewater treatment
components to adapt to changes in wastewater characteristics and the ability
of the wastewater management system to serve future development areas and
to undergo upgrading and/or expansion to comply with changes in water quality
goals. Maintainability considerations include the complexity of equipment,
frequency of maintenance down time, and efficiency of providing required
maintenance.
11-24
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TABLE II-7
COST SUMMARY FOR 2.55 MGD DISCHARGE FROM
SEA PINES PSD - FOREST BEACH PSD TO LAWTON CANAL (1)
Component
Discharge To Lawton Creek
Sand Filters - Dual
Units § 2.55 mgd
Project Costs(2) Land Costs Salvage Value Annual 0 § M
EAC
1,777,284
710,914
37,409
Cn
Total
$1,777,284
$ 710,914
$ 37,409
$206,100
(1) All costs in 1985 present worth based upon 15-year planning period ending in the year 2000, 7.125 percent
interest and 1980 price levels. Capacities based upon JPC flows.
(2) Includes a 30-percent allowance for engineering, financing, and contingencies.
-------
TABLE I1-8
i
M
O\
Component
COST SUMMARY FOR 2.55 MGD DISCHARGE FROM
SEA PINES PSD - FOREST BEACH PSD TO CALIBOGUE SOUND CD
Project Costs (2) Land Costs Salvage Value Annual 0 6 M EAC_
Discharge To Calibogue Sound
o rr A 138 858 --- 50,202 15,652
. Pumping - 2.55 mgd l-5S,Sb»
. Force Main - 18,500 Ft. 921,023 — 481,766 1,552
@ 14" Dia.
. Subaqueous Outfall - 4,000 Ft.
@ 14" Dia. and _„„ ,,,
Diffuser Structure 973,978 — 509,466
Total $2,033,864
$1,041,434 $17,204 $201,300
(1) All costs in 1985 present worth based upon 15-year planning period ending in the year 2000, 7.125 percent
interest and 1980 price levels. Capacities based upon JPC flows.
(2) Includes a 30-percent allowance for engineering, financing, and contingencies.
-------
TABLE II-9
COST SUMMARY FOR 2.55 MGD DISCHARGE FROM
SEA PINES PSD - FOREST BEACH PSD BY RAPID INFILTRATION (1)
Component
Wetlands Application
Pumping - 1.0 mgd
. Force Main - 12,000 Ft @ 10" Dia.
. Diffusers - 6,000 Ft @ 4" Dia.
Woodlands Irrigation
Pumping - 0.25 mgd
. Force Main - 25,500 Ft @ 6" Dia.
Solid-set Spray Irrigation System
Rapid Infiltration
Pumping -1.3 mgd
. Force Main - 1,500 Ft § 10" Dia.
Infiltration Beds
Total
Project Costs(2) Land Costs(3) Salvage Value Annual 0 § M
EAC
101,088
361,928
36,000
84,240
535,500
215,280
102,960
45,000
484,380
5,275,050(4)
$1,966,376
621,000(5)
$5,896,050
36,547
172,278
17,136
30,456
254,898
4,587,000
37,224
21,420
$5,156,959
11,664
685
342
10,368
1,191
7,419
11,952
92
37,260
$80,973
$748,000
(1) All costs in 1985 present worth based upon 15-year planning period ending in the year 2000, 7.125 percent
interest and 1980 price levels. Capacities based upon JPC flow.
(2) Includes a 30-percent allowance for engineering, financing, and contingencies.
(3) Includes a 15-percent allowance for administrative and legal costs.
(4) Based upon purchase of Parcels 15-317, 15-314, 15-258, and 15-163 in their entirety to yield net usable
area of approximately 32 acres.
(5) Based upon total area of 18 acres to provide for 12 acres of bed area. Costs taken at $30,000 per acre
from Wilbur Smith § Associates report prepared for Sea Pines PSD.
-------
TABLE 11-10
COST SUMMARY FOR 2.55 MGD DISCHARGE FROM
SEA PINES PSD - FOREST BEACH PSD BY SPRAY IRRIGATION ON-ISLAND AT GARDNER-MATTHEWS (1)
Component Project Costs (2) Land Costs (3) Salvage Value Annual 0 § M EAC
Woodlands Irrigation
Pumping - 2.55 mgd
. Force Main - 54,000 Ft.
@ 16" Dia.
Solid Set Spray Irrigation
System
Storage - 25 Million Gallons
i—i
i—i
M Total $6,165,741 $8,763,000 $9,127,619 $103,125 $1,395,826
(1) All costs in 1985 present worth based upon 15-year planning period ending in the year 2000, 7.125 percent
interest, and 1980 price levels. Capacities based upon JPC flows.
(2) Includes a 30-percent allowance for engineering, financing and contingencies.
(3) Includes a 15-percent allowance for administrative and legal costs.
(4) Based upon purchase of 500 acres within Parcel 11-1 to provide for spray area of approximately 305 acres
plus adequate buffer area @ $15,000 per acre.
(5) Based upon purchase of 8 acres within Parcel 11-1 for storage pond.
138,858
3,061,800
2,664,090
300,993
:::
8,625,000(4)
138,000(5)
50,202
1,457,417
7,500,000
120,000
15,652
3,866
81,893
1,714
-------
TABLE II-ll
SEA PINES PSD -
Component
COST SUMMARY FOR 2.55 MGD DISCHARGE FROM
FOREST BEACH PSD BY SPRAY IRRIGATION OFF-ISLAND AT UNION CAMP (1)
Pumping - 2.55 mgd
Booster - 2.55 mgd
Land Based Force Main -
113,900 Ft. 8
16" Dia.
Subaqueous Force Main -
9,000 Ft. @
16" Dia.
Solid Set Spray
Irrigation System
Storage - 23 Million Gallons
Total
Project Costs(2) Land CostsC3) Salvage Value
138,858 -- 50,202
138,858 -- 50,202
6,458,130 --- 3,378,099
1,205,100
2,664,090
300,993
630,360
2,875,000(4) 2,500,000
46,000(5) 40,000
$10,906,029
$2,921,000 $6,648,863
Annual 0 § M
15,652
15,652
8,154
644
81,893
1,714
$123,709
EAC
$1,392,174
(1) All costs in 1985 present worth based upon 15-year planning period ending in the year 2000, 7.125 percent
interest, and 1980 price levels. Capacities based upon JPC flows.
(2) Includes a 30-percent allowance for engineering, financing and contingencies.
(3) Includes a 15-percent allowance for administrative and legal costs
(4) Based upon purchase of 500 acres from Union Camp to provide spray' area of approximately 305 acres 6 $5,000
er
(5) Based upon purchase of 8 acres for storage pond.
-------
TABLE 11-12
COST SUMMARY FOR SEA PINES PSD - FOREST BEACH PSD
WASTEWATER MANAGEMENT ALTERNATIVES Cl)
i
OJ
o
Alternative
Lawton Canal
Calibogue Sound
Rapid Infiltration
Spray Irrigation
On-Island
Spray Irrigation
Off-Island
Construction
Cost
Project
Cost
Salvage
Value
0 6 M Cost
1985
2000
0 5 M
Present
Worth
Total
Present
Worth
EAC
$ 1,367,200 $ 1,777,300 $ 710,900 $27,300 $ 37,400 $ 337,800 $ 1,861,900 $ 206.100
$ 1,564,500 $ 2,033,900 $1,041,400 $12,600 $ 17,200 $ 155,400 $ 1,818,300 $ 201,300
$ 6,639,700 $ 7,862,400 $5,157,000 $59,100 $ 81,000 $ 731,500 $ 6,757,000 $ 748,000
$12,362,900 $14,928,700 $9,127,600 $75,300 $103,100 $ 931,600 $12,609,000 $1,395,800
$10,929.300 $13,827,000 $6,648,900 $90,300 $123,700 $1,117,400 $12,576,100 $1,392,200
(1) All costs in 1985 Present Worth based upon 15-year planning period ending in the year 2000, 7.125 percent interest and
1980 price levels. Based on JPC flows with 2.55 MGD disposed by the various alternatives.
-------
The relative operability of the alternatives is summarized in Table
IT-13. On an overall basis, discharge to Calibogue Sound as a supplement
to golf course irrigation is the most operable. Next is discharge to Lawton
Canal. Spray irrigation is next, and rapid infiltration is least operable.
Certain general conclusions can be drawn from the operability evaluation
as follows:
- Facilities with lower treatment levels are
easier to maintain than those with higher
treatment levels.
- Spray irrigation of effluent is less re-
liable and less maintainable than discharge
to surface waters. (This evaluation is based,
in part, on the operational unknowns associated
with the soils and topographic conditions
at potential land application sites).
- Rapid infiltration is less reliable and
less maintainable than spray irrigation.
This evaluation is based, in part, on the
potential for groundwater contamination and
the possible requirement for additional
nitrogen removal at the Sea Pines PSD
plant (Based upon studies performed for
the Sea Pines PSD by Wilbur Smith § Associates
and preliminary indications from DHEC, rapid
infiltration is less desirable than other dis-
posal options available to the Sea Pines PSD -
Forest Beach PSD).
Implementability Evaluation
The practicalities of implementing a specific wastewater management
plan must be considered, together with cost, environmental impacts and
operability evaluations, as an important part of the cost-effectiveness
analysis. The purpose of the implementability rating is to assess the pro-
spects for successful implementation of an alternative based on its potential
for general public acceptance and political realities in the study area.
Unlike the other evaluations in the cost-effectiveness analysis (costs,
environmental impacts, and operability), the implementability rating is not
independent, but is somewhat dependent on the results of the other evalua-
tions. This is especially the case with public acceptance since costs and
environmental impacts evaluations probably have the greatest influence on
public acceptability. For example, if an environmentally favorable plan
is significantly more costly, the public must decide how much it is willing
to pay (in terms of monetary costs) for environmental benefits.
11-31
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Alternative
Discharge to Lawton Canal
TABLE 11-13
SEA PINES PSD - FOREST BEACH PSD
WASTEWATER MANAGEMENT ALTERNATIVES
OPERABILITY EVALUATION
Reliability
Flexibility
Maintainability
Overall
Operability
i
OJ
ro
Discharge to Calibogue
Sound
Rapid Infiltration
Spray Irrigation On-Island
Spray Irrigation Off-Island
+ Indicates decided advantage
0 Indicates no particular advantage
Indicates possible disadvantage or drawback
-------
An important factor in public acceptance is the local annual cost
associated with a wastewater management alternative. The local annual cost
includes annual operation and maintenance costs plus the annualized local
share of the cost of constructing the wastewater facilities. This is a
measure of annual revenue requirements, and therefore, the actual cost to
the users. Table 11-14 presents a breakdown of estimated annual costs for
each of the five alternatives based on the JPC-based flow. The assumptions
for developing these local annual costs are as follows:
- EPA will only fund wastewater facilities
sized to handle the 1.8 mgd now being dis-
charged to Lawton Canal. Wastewater facili-
ties required for additional flows will be
funded at the local level.
- Eligible costs for EPA funding equal 90
percent of the project cost.
- Spray irrigation, rapid infiltration, and
wetlands discharge including land costs
are eligible for 85 percent funding.
The associated financial impacts of each alternative have also been
evaluated. Estimated annual user charges have been determined as a general
indication of the cost difference to the user. User charges are developed
as follows:
, Annual Local Costs
User charges = Number of EDU.S
EDU's represent the average residential user. Other users such as commercial
and industrial may be represented in terms of number of EDU's. EDU's are
based upon the total water consumption divided by estimated typical dwelling
unit consumption. For the Sea Pines PSD - Forest Beach PSD, the number of
EDU's is taken at 7,810 for the year 1985 (initial year of operation for
the selected alternative). This is equal to an interpolated JPC-based flow
of 2.5 mgd divided by 320 gpd per EDU.
Table 11-14 presents the estimated annual user charge for each of the
five alternatives. These estimated charges are in addition to the charges
presently being paid.
The relative implementability of the alternatives is summarized below.
None of the alternatives has a decided advantage; instead, there are distinct
drawbacks for each. Several general conclusions can be drawn from the
implementability evaluation as follows:
- Discharge to surface waters is less acceptable
to some regulatory agencies than spray irrigation
on large tracts of land. The issuance of the
required NPDES and Coastal Council Permits
will therefore likely be very time-consuming due
to administrative procedures of affected regulatory
agencies.
11-33
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TABLE 11-14
LOCAL ANNUAL COST SUMMARY FOR
SEA PINES PSD - FOREST BEACH PSD
WASTEWATER MANAGEMENT ALTERNATIVES
Alternative
Lawton Canal
Calibogue Sound
Rapid Infiltration
Spray Irrigation
On-Island @
JPC
Project
Cost(l)
$ 1,777,300
$ 2,033,900
$ 7,862,400
$14,928,700
Assumed
EPA
Grant (2)
$ 1,038,200
$ 1,246,100
S 5,746,100
$ 9,328,000
Local
Share
$ 739,100
$ 787,800
$2,116,300
$5,600,700
Annual
Debt
Service (3)
$110,900
$118,200
$317,600
$840,500
Annual
0 § M(4)
$ 27,300
$ 12,600
$ 59,100
$ 75,300
Total
Annual
Cost
$138,200
$130,800
$376,700
$915,800
Annual
User
PV» o -p rrfz ( C ^
marge {b)
$ 17.70
$ 16.75
$ 48.23
$117.26
Gardner-Matthews
Spray Irrigation
Off-Island 8
Union Camp
$13,827,000 $ 8,777,400 $5,049,600 $757,800 $ 90,300 $848,100
$108.59
(1)
Taken from Table 11-12 of PDEIS
roTunS
UP°"
(4) Based upon estimated 1985 0 S M cost as shorn in Table 11-12 of PDEIS
(5) Equal to Total Annual Cost divided by 7,810 EDU's.
««-««,, and 85 percent funding
d h rge o'LTon CanaT' 9° ""'"" °f
0Cana and ,0 percent
-------
Construction of a subaqueous outfall to Calibogue
Sound or the commitment of large tracts of land
for spray irrigation are largely irreversible and
less flexible than maintaining the existing dis-
charge to Lawton Canal.
Conveyance of treated wastewater outside of the
PSD's for land application will involve more com-
plex institutional arrangements than other alterna-
tives. Obtaining large tracts of land voluntarily
for use as spray irrigation sites would be difficult,
especially on-island. It is the opinion of the Office
of the Attorney General for the State of South
Carolina that the condemnation authority of Beaufort
County can be used to assist the Sea Pines PSD -
Forest Beach PSD in obtaining land for spray ir-
rigation. A copy of this written opinion is
included as Appendix D.
Costs for the total land application of treated
wastewater are substantially higher than for either
discharge to Calibogue Sound or Lawton Canal.
No-Federal Action Alternative
If EPA does not participate in the funding of a wastewater management
program for the Sea Pines PSD - Forest Beach PSD, then the costs for improve-
ment and/or expansion of the PSD wastewater facilities must be borne entirely
at the local level. As a result, the costs to users would significantly in-
crease as shown in Table 11-15.
2. BROAD CREEK PSD
The Broad Creek PSD wastewater facilities serve the Palmetto Dunes re-
sort area. Wastewater is pumped to and treated at a 600,000 gpd secondary
treatment plant which consists of two parallel 300,000 gpd extended aeration
activated sludge units. Treated effluent from the plant is disinfected and
disposed of by spray irrigation. The peak monthly average flow to the plant
during 1980 was 391,000 gpd.
Treated wastewater from the Broad Creek PSD plant is sprayed onto two
areas: either onto eighteen holes of the Fazio golf course located within
the Palmetto Dunes resort, or onto a 20-acre site located across Route 278
from the treatment plant. Manually-operated valves regulate the conveyance
of wastewater to these sites. To date, the two spray areas have been suf-
ficient to dispose of the treated wastewater from the Broad Creek PSD plant.
11-35
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TABLE 11-15
ESTIMATED USER COST SUMMARY FOR
SEA PINES PSD - FOREST BEACH PSD
WASTEWATER MANAGEMENT ALTERNATIVES
Alternative
Lawton Canal
Calibogue Sound
Rapid Infiltration
Spray Irrigation On-Island
Spray Irrigation Off-Is land
Estimated Annual User Cost Increase
EPA Funding
$ 17.70
$ 16.75
$ 48.23
$117.26
$108.59
No EPA Funding
$ 37.64
$ 40.69
$158.64
$296.50
$277.26
11-36
-------
Projected Wastewater Flows
Wastewater flows for the year 2000 are based upon the "peak month"
population and per capita flow rates for each of the population components.
Peak monthly average flows for the year 2000 for the Broad Creek PSD are
0.64 mgd (based on OBERS) and 0.81 mgd (based on JPC). By comparison, the
Broad Creek PSD has indicated that the year 2000 flow will be in the range
of 1.8 mgd to 2.0 mgd. Some of the difference can be attributed to con-
sideration of occupancy rates. When the JPC-based year 2000, peak month
population is adjusted to reflect 100 percent occupancy, a corresponding
wastewater flow of 1.25 mgd is arrived at.
Wastewater Management Program
Present plans of the Broad Creek PSD envision expansion of the existing
0.6 mgd treatment plant to 1.2 mgd in 1981-1982. The proposed expansion
includes the modification of the two existing 300,000 gpd extended aeration
activated sludge units to the contact stabilization process. A second
expansion from 1.2 to 1.8 mgd is envisioned by July 1984 and a third from
1.8 to 2.4 mgd by July 1988.
As previously indicated, treated wastewater is presently sprayed onto
the Fazio golf course and the existing 20-acre spray site. As needs dictate,
the Trent Jones golf course will also be irrigated with treated wastewater.
These two courses and the existing 20-acre spray site are adequate to handle
the OBERS and JPC-based flows projected for the year 2000.
However, additional spray areas will be required to match the design
capacity of the proposed 1.2 mgd plant. A third golf course is planned for
the Palmetto Dunes Resort which can be utilized for spray irrigation. The
wastewater application rates at the Fazio course should be closely moni-
tored in order to better assess seasonal variations in irrigation demands.
This will enable more accurate decisions to be made regarding the need and
timing for using wastewater to irrigate the other golf courses. This approach
will indicate whether the three golf courses and the 20-acre spray site will
be adequate to handle the wastewater flows which the Broad Creek PSD plans
to provide for, or whether additional areas must be reserved for spray ir-
rigation. Rather than totally rely upon spray irrigation as a disposal method,
the PSD may opt to pursue the possibility of a discharge to Port Royal Sound.
No significant water quality impacts would be expected from such a discharge
based upon the assimilative capacity of the Sound (see Table II-2, Page II-8).
However, detailed studies would be required to determine the optimal location
and orientation of the diffuser.
EPA Participation
The costs of the Broad Creek expansion program must be borne entirely at
the PSD level. Current EPA policy prevents their participation in funding of
wastewater facilities greater than the OBERS population. Consequently, the
program described above for the Broad Creek PSD represents the no-action
alternative with respect to Federal funding.
11-37
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5. HILTON HEAD NO. 1 PSD
The Hilton Head No. 1 PSD wastewater facilities primarily serve apart-
ments, condominiums, and commercial establishments located within the
boundaries of the PSD. Single-family residences within the Port Royal
Plantation (except two) are served by septic tanks. Current flows average
about 175,000 gpd. Treatment facilities were constructed in 1971 and con-
sist of an unlined oxidation pond followed by two unlined holding ponds.
Wastewater from the oxidation pond percolates radially into the ground-
water, and analysis of samples taken from observation wells suggests that
groundwater contamination is occurring. As a result, DHEC has placed a
moratorium on additional connections to the system.
Wastewater from the Port Royal Inn, which is located within the Port
Royal Plantation, is pumped to a 15,000 gpd package activated sludge treat-
ment plant. Effluent from the plant is discharged into the plantation's
lagoon system. A recent water quality study by DHEC indicates that the
discharge has caused nutrient enrichment of these receiving waters.
In order to provide additional capacity, private development has
constructed an interim 440,000 gpd treatment facility adjacent to the PSD's
existing oxidation pond. This plant will allow the construction of new
residential units within the PSD. The interim facility consists of a
multi-celled aerated lagoon and holding pond. Treated effluent is pumped
from the plant, under Route 278, to Port Royal Plantation for irrigation
of the Barony and Robbers Row golf courses. DHEC has approved the use of
these courses for the spray irrigation of at least 800,000 gpd of wastewater.
Construction is now underway on a new 800,000 gpd plant to serve ex-
isting and future needs within the service area. Completion is scheduled
for February 1982. A completely new facility is being built because of the
inadequacy of the existing unlined oxidation pond. Components include a
complete mix activated sludge package plant with sand drying beds for sludge
dewatering. As part of the Hilton Head No. 1 project, the Port Royal Inn
package plant will be abandoned and a pumping station and force main con-
structed to convey wastewater to the new PSD facilities. The entire project
is being funded, in part, by the EPA Construction Grants Program.
The unlined oxidation pond and the two holding ponds now existing at
the Hilton Head No. 1 PSD facility will be renovated and lined with an
impermeable material. These ponds will then be available to store treated
effluent from the new package plant prior to spray irrigation.
Projected Wastewater Flows
Peak monthly average flows for the year 2000 for Hilton Head No. 1 PSD
are 0.62 mgd (based on OBERS) and 0.76 mgd (based on JPC). Hilton Head No.
PSD has recently indicated that the wastewater flows already permitted or
committed to proposed development exceed the projected year 2000 wastewater
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flow based upon the JPC population. Part of this difference is attribu-
table to the EIS's consideration of less than 100 percent occupancy rates.
Wastewater Management Program
The Hilton Head No. 1 PSD has recently asked DHEC to allow the 440,000
gpd "interim" facility to remain in operation after construction of the new
800,000 gpd plant has been completed. However, the existing Barony and
Robbers Row golf courses cannot accommodate the total capacity of 1.24 mgd
which would result, although a third golf course in the Port Royal Planta-
tion is planned for construction by the Hilton Head Company within the next
four years.
The PSD could elect to obtain additional land for use as a spray area
to supplement golf course irrigation. Of existing undeveloped areas, the
Hilton Head Airport appears to be most worthy of consideration. Preliminary
indications from the Beaufort County Aviation Board are that they would be
amenable to the spray irrigation of airport property provided Hilton Head
No. 1 would assume the responsibility for mowing and maintaining the spray
areas.
Discharge of excess effluent through a subaqueous outfall and diffuser
into Port Royal Sound is another alternative. No significant water quality
impacts are anticipated. Detailed studies would be required to determine
the optimal location and orientation of the diffuser. Opposition to this
alternative is likely to be encountered from the public, fishing industry,
and regulatory agencies. Therefore, the most prudent course of action for
the Hilton Head No. 1 PSD may be to initiate negotiations for the purchase,
or long-term lease, of additional land to use as spray areas. Use of the
Hilton Head Airport should be pursued immediately. The total amount of land
required will be dependent upon the ultimate capacity which the Hilton Head
No. 1 PSD desires to construct and the seasonal limitations of the Robbers
Row and Barony golf courses.
Accurate records should be kept on the amount of wastewater used to
irrigate the Barony and Robber's Row courses so that periodic comparisons
can be made regarding seasonal golf course use versus wastewater flow.
These data will be useful in projecting the additional spray areas required
to supplement golf course irrigation.
EPA Participation
Additional EPA funding will not be available for any future needs of
the Hilton Head No. 1 PSD in excess of the 800,000 gpd facilities now under
construction (no action alternative). Therefore, the costs for further ex-
pansion of the Hilton Head No. 1 PSD treatment facilities beyond 800,000 gpd
and for securing additional spray irrigation areas must be borne by developers.
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4. HILTON HEAD PLANTATION
Hilton Head Plantation is served by treatment facilities owned and
operated by the Hilton Head Plantation Utilities Corporation. The corpora-
tion is not eligible to receive EPA Rr.-jnt funds for improvements and/or
additions to wastewater facilities.
The Hilton Head Plantation wastewater facilities serve developed property
within the plantation boundaries, as well as the Hilton Head Hospital and
the Hilton Head Elementary School. Current wastewater flows to the plant
average approximately 130,000 gpd. Wastewater is conveyed to and treated
at a 500,000 gpd secondary treatment plant. Treated effluent from the plant
is disinfected and disposed of by spray irrigation. The existing spray
irrigation area consists of 53 acres and is located at the Seabrook Farm
near the plant. Treated effluent is sprayed via a portable spray gun onto
open fields. The Seabrook spray area is adequate to handle over 400,000 gpd.
Projected Wastewater Flows
Peak monthly average flow projections for the year 2000 for Hilton Head
Plantation are 0.31 mgd (based on OBERS), 0.44 mgd (based on JPC). These
compare to a wastewater flow of approximately 0.72 mgd based upon the
plantation's projections that 2,885 dwelling units will be constructed
by the year 2000 resulting in a resident population of 7,213.
Wastewater Management Program
The Hilton Head Plantation plans to expand the existing 0.5 mgd acti-
vated sludge package plant to 1.0 mgd during 1984, based upon anticipated
housing starts. The resulting capacity will be sufficient to accommodate
the year 2000 population which the plantation projects.
As previously indicated, treated wastewater is currently sprayed
onto "approved" open areas of the 53-acre Seabrook Farm complex. Additional
areas will be required to match the treatment plant capacity of 1.0 mgd.
There are two golf courses in the plantation (Dolphin Head, Bear Creek).
A third course is now under construction (Oyster Reef), and a fourth is
planned. A proposal to utilize the Dolphin Head golf course as a spray
irrigation area for the disposal of treated wastewater is now under considera-
tion by DHEC.
Based upon present flow projections, it appears that spray irriga-
tion of the Seabrook Farm area must be maintained. Spray irrigation of the
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Dolphin Head course will supplement the continued use of the existing
Seahrook Farm area to adequately handle the year 2000 wastewater flows. The
remaining three courses will he available to accommodate the increased waste-
water flows as the plantation progresses toward maximum build-out beyond the
year 2000.
Available information on current irrigation practices at the Dolphin
Head golf course indicate that the course receives an average of 281,000
gpd (0.85 inches per week) during the year. Peak application rates occur
in July and August (538,000 gpd or 1.63 inches per week); minimum applica-
tion rates occur in January and February (73,000 gpd or 0.22 inches per
week). Additional data should be collected once wastewater irrigation of
the course begins so that updated comparisons can be made regarding seasonal
golf course capacities versus wastewater flow. Analysis of these data will
determine the timing required for implementing wastewater irrigation at the
remaining courses.
In addition to golf course irrigation, Hilton Head Plantation has
indicated an interest in developing a wetlands application system within
the Cypress Swamp Conservancy in order to restore the natural water table
to preserve the area's habitat. This concept is now under consideration by
DHEC.
EPA Participation
As previously indicated, Hilton Head Plantation's wastewater treatment
and disposal facilities are not eligible for EPA funding. Therefore, any
improvements and/or expansions to the system will be funded entirely at the
local level, representing a "no Federal action" alternative.
5. NON-PSD AREAS
Areas of Hilton Head Island which lie outside the boundaries of the
Hilton Head Plantation or the existing PSD's are served by septic tank-
drainfield systems, with the exception of the Mariner's Cove Club and the
Northside Trailer Park. There are no areas where widespread septic tank
malfunctions are known to occur. An overview of the wastewater management
programs for the non-PSD areas, Mariner's Cove, and Northside Trailer Park
is presented below.
Community Wastewater Management Alternatives
Although there are no known areas where widespread septic tank mal-
functions are occurring, generalized alternatives have been identified and
costs developed on a "per household" basis. The alternatives identified
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include a community sand mound system, a package plant/spray irrigation
alternative, and conveyance to an existing PSD for treatment and disposal
(based upon several distances). The annual cost per household is shown
in Figure II-8 for each of these alternatives, expressed as a function of
the number of households connected.
These annual costs include both the amortized project costs including
land (at 7.125 percent, 25 years, 10 percent coverage) and the estimated
annual costs for operation and maintenance of the system. Costs are based
upon 100 percent local funding. Costs for collection of wastewater are not
included for the package plant or PSD alternative. Costs for the community
sand mound alternative include the costs related to construction of the area
mound; costs for pumping from each septic tank to the mound are not included.
These costs are very general in nature and are intended to show the
relationship between the three alternatives as a function of population.
More definitive costs can be developed for a specific area experiencing
septic tank problems based upon location, area soils and demographic conditions.
The generalized costing effort previously presented serves as a basis
from which to select wastewater management systems for a given area. Waste-
water management costs for several representative communities in the non-PSD
areas have been developed in order to determine approximate costs to users,
and therefore the likely feasibility of each. The Chaplin, Muddy Creek, and
Baygall areas were selected for investigation because of their size, density,
and distance from existing wastewater treatment facilities. Wastewater systems
for these areas are presented below.
Chaplin - The Chaplin community lies along Highway 278 between Folly Field
Road (south of Port Royal Plantation) and north of Palmetto Dunes resort.
A physical house count of the area including Bradley Beach, Burkes Beach,
and Singleton Beach Roads tallied 108 residences and trailers; most of the
area is of medium density. Because of its relative proximity to the Hilton
Head No. 1 PSD, collection and conveyance of wastewater to PSD facilities for
treatment and disposal is deemed most cost-effective.
A conventional gravity collection system with pumping station and
force main, small-diameter pressure system with grinder pumps, and a vacuum
system were considered for the area. Use of a vacuum system was selected
because of cost considerations and the ability to serve future infill and
perimeter development of the area without major modification.
Costs are developed for the vacuum system including all service connections,
piping and fittings, valves, vacuum collection and pump station, and force main
to the Hilton Head No. 1 PSD. Total project costs are presented in Table 11-16.
Estimated annual user charges are developed based upon 100 percent local
funding; costs are also developed assuming that 75 percent funding can be ob-
tained, whether from EPA or other sources. As shown, annual user costs range
from approximately $230 to $536, based upon 25 percent and 100 percent local
funding respectively. A pro-rata share of the costs for debt service and
operation and maintenance of the new Hilton Head No. 1 PSD plant are not in-
cluded. These costs could add approximately $100 to $125 per year per household.
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2000
100
20
50 100
NO. OF HOUSEHOLDS CONNECTED
300
LEGEND
COMMUNITY EXTENDED AERATION
PACKAGE PLANT W/SPRAY IRRIGATION
CONVEYANCE TO NEAREST PSD FOR
TREATMENT AND DISPOSAL
COMMUNITY SAND MOUND SYSTEM
WASTEWATER TREATMENT
AND DISPOSAL COSTS
FOR N ON-PSD AREAS
FIGURE Tf-8
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TABLE 11-16
NON-PSU COMMUNITIES
WASTEWATER MANAGEMENT ALTERNATIVES
TOTAL ANNUAL LOCAL COSTS
Alternative Description Project Cost(l) Assumed Grant Local Share Annual Debt Annual Total Annual Number of Initial Annual
Service(I) 0 6 M Costs Initial User Char?*
Users Per Household(4)
Chaplin - vacuum sewer $513.500 -0- $513.500 $49,019 $8,856 $57,875 108
system with conveyence
of wastewater to Milton $513.500 $346.613(2) $166,887 $15,931 $8,856 $24,787 108
Head No. 1 PSD
Muddy Creek and Baygall - $670,423 -0- $670.423 $63,999 $6,864 $70,863 78
community sand mound
n system to servo six $670,423 $452,536(2) $217,887 $20,799 $6,864 $27,663 78
hj~l homes
c/q
Individual Home - with $ 6,883 -0- $ 6,883 $ 657 $ 45 $ 702 1
malfunctioning septic
tank drainfield $ 6,883 $ 4.646(2) $ 2,237 $ 214 $ 45 $ 259 1
$536
$230
$909
$355
$702
$259
(1) Includes 30 percent allowance for engineering, legal, and administrative costs.
(2) Based upon 75 percent funding of eligible costs. Eligible costs assumed to equal 90 percent of project cost.
(3) Estimated debt service based upon 7.125 percent interest, 25-year amortization period, and 10 percent coverage.
(4) Estimated user charges are presented only for the purpose of determining financial feasibility and should not be interpreted
as
recommended charges.
-------
Project costs are based upon the existing population which will be
served. Future development in the area would tend to decrease the costs for
all users. Also, the initial project could be trimmed to the more populous
areas of the community, with service for the extreme portions of Bradley Beach,
Burkes Beach, and Singleton Beach Roads deferred to a second phase. Total
project costs and user charges would thus be reduced.
Muddy Creek Area - The Muddy Creek area along Muddy Creek Road, Bryan Road,
and Spanish Wells Roads (between Spanish Wells Plantation and Pond Drive)
contains approximately 78 residences. The homes are clustered in small groups
with substantial distances between the clusters. Because of the small number
of homes, their "cluster" grouping, and their substantial distance from any
existing wastewater treatment facilities, an alternate approach to conventional
gravity collection and pumping was evaluated for the area.
Community sand mound systems are envisioned; each "cluster" of homes
would be served by an elevated sand mound which would be located nearby. Waste-
water would be pumped from the septic tank at each home to the community mound
for application. The mound would serve as a physical and biological medium
through which the applied wastewater would filter before reaching natural soil.
Costs for a typical system have been developed based upon six homes per
community mound. The size of the mound area required to serve six homes is
approximately 16,000 square feet. Project costs cover construction of the
sand mound, pumping and related controls at each home, piping from each home
to the sand mound, land purchase, and engineering. Total approximate pro-
ject costs for a six-home system are presented in Table 11-16; estimated annual
user charges are also developed based upon either 100 percent local funding
or 25 percent local funding assuming 75 percent "outside" funding could be
obtained. As shown, annual user costs range from approximately $305 to $909
for 25 percent and 100 percent local funding respectively.
Baygall Area - The Baygall community is located at the end of Beach City Road
and encompasses residences along Fish Haul, Baygall, and Mitchellville Roads.
At present, the community population is too small and too far from existing
wastewater treatment facilities to consider a conventional wastewater col-
lection and conveyance system.
Because of similarities to the Muddy Creek area, costs have been developed
for a community sand mound system for the Baygall area. Again, system costs
are based upon a six-home community sand mound, with necessary pumping
facilities located at each individual home. Total project costs, local costs,
and approximate annual user charges are the same as those developed for the
Muddy Creek area. These costs are shown in Table 11-16.
Individual Homes - When isolated instances of septic tank malfunctions occur,
corrective measures are made on an individual rather than community basis. One
possible solution for a malfunctioning drainfield is the construction of an
elevated sand mound for disposal of the septic tank effluent. Generalized
costs are shown in Table 11-16. Estimated annual user costs are also shown
in the table; these costs presume that construction and operation and main-
tenance costs will be financed through some form of public management agency.
Costs are based upon either 100 percent or 25 percent local funding.
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Northside Trailer Park
The Northside Trailer Park is located on the north end of Hilton
Head, off of Guratree Road. Residents of the trailer park have been asked by
the Hilton Head Plantation Company to vacate the property after which the
existing 10,000 gpd package plant will be abandoned.
Mariner's Cove
The Mariner's Cove plant provides treatment for the wastewater generated
from forty units of the Mariner's Cove Club complex, which is located south
of Route 278 near the bridge to Pinckney Island. Effluent from the plant is
spray irrigated. The plant is owned by the Mariner's Cove Horizontal Property
Regime.
Consideration is being given to the creation of a Public Service District,
through appropriate legal mechanisms, to assume the provision of wastewater
treatment and disposal for the Mariner's Cove complex. The exact boundaries
that the PSD would encompass are uncertain at this time.
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CHAPTER III
AFFECTED ENVIRONMENT, ENVIRONMENTAL CONSEQUENCES
OF THE ALTERNATIVES AND MITIGATIVE MEASURES
with the State of the hland?'
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CHAPTER III - AFFECTED ENVIRONMENT, ENVIRONMENTAL
CONSEQUENCES OF THE ALTERNATIVES AND
MITIGATIVE MEASURES
PART A. INTRODUCTION
This chapter summarizes the existing natural and man-made environ-
ment of the study area, discusses the environmental impacts of the alterna-
tives and proposes possible measures to mitigate these impacts. The
purpose of the environmental setting summary is the establishment of ex-
isting baseline conditions in the area. The impacts of the various al-
ternatives are gauged against these existing conditions. The discussion
is organized to first present primary impacts expected from the implementa-
tion of the alternatives. This section is followed by a discussion of the
secondary impacts expected from the various alternatives. A complete dis-
cussion of Hilton Head's existing environment is presented in the complete
Environmental Inventory which is bound separately as a Reference Document.
PART B. PRIMARY IMPACTS
1. SURFACE WATER RESOURCES
High water quality conditions surround Hilton Head with one significant
exception. The coliform levels required to maintain SA quality waters are
not being met in Lawton Creek and some areas of Broad Creek. This has
caused the closing of these waters to shellfish harvesting.
Routine monitoring of the shellfish beds surrounding Hilton Head has
been conducted since the mid-19601s. During the 1977-1978 oyster season the
Division of Shellfish and Recreational Waters found unusually high fecal
coliform counts during routine investigations of oyster meats from shell
stock taken from Lawton Creek. This resulted in an analysis of surface water
samples from Lawton Creek in July 1978 which revealed high total and fecal
coliform counts. In August 1978 DHEC closed shellfish beds from "all waters
and bottoms of Lawton Creek and Canal and Point Comfort Creek and the adjacent
shore of Broad Creek running the length of Buck Island and Marsh (refer to
Plate 1-3)". Prior to this time harvesting of oysters had only been pro-
hibited by DHEC from "the waters and bottoms within a 1000 ft. radius of
Palmetto Bay Marina, Harbour Town Marina, and Baynard Cove Marina".
TII-1
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The 1978 closure of Lawton Creek to shellfishing precipitated a number
of special water quality studies by DHEC. These studies concentrated on
the bacterial and hydrologic characteristics of the Sea Pines PSD treatment
plant, Lawton Canal, Lawton Creek, and Broad Creek. The locations of samp-
ling stations are shown on Plate III- 1.
Water quality and bacteria samples were collected during dry and wet
climatic periods to evaluate the extent of point and non-point source pollu-
tion. A program of groundwater sampling was also conducted within Sea Pines
in order to obtain additional data regarding possible sources of non-point
pollution.
These studies indicated that state standards and Federal criteria for
shellfish waters are violated in the Lawton Creek, Baynard Creek, and Point
Comfort Creek Drainage Systems. While concentrations of bacteria in the
Sea Pines wastewater treatment plant effluent remained consistently low,
bacterial levels in the surface waters increased with rainfall events and
tended to increase from high to low tide. These fluctuations point to non-
point pollution originating in the interior of Hilton Head Island and draining
into the shellfish waters of Broad Creek. Specific sources of non-point
pollution could not be identified.
The quality of surface waters surrounding Hilton Head would be impacted
by two of the alternatives: the Calibogue Sound discharge, and the continua-
tion of the Lawton Canal discharge. A stimulation of greater primary produc-
tivity due to increased nutrient loadings and dissolved oxygen fluctuations
could be expected from either. These impacts would be greater for a dis-
charge into Lawton Canal than for a discharge into Calibogue Sound which
has a larger assimilative capacity as indicated previously in Table II-2.
Circulation studies would be required for the Calibogue Sound alternative
to select the specific location and orientation of the outfall diffuser which
would minimize impacts on water quality. Under both discharge alternatives,
chlorine disinfection would introduce chlorinated compounds into the water
column.
A continued discharge to Lawton Canal would result in an increase in
the size of the buffer zone closed to shellfish harvesting as wastewater
flows continued to increase. The size of the buffer zone is related to the
time required to shutdown shellfish harvesting activities in the event of
total plant failure.
An alternative making Federal funding contingent upon the correction
of the non-point source problem is the only alternative which encourages im-
provement in the non-point source situation. Under this alternative, no
Federal funds would be provided for wastewater disposal unless non-point
source control measures are implemented.
Minimal impacts could occur from runoff at the woodlands irrigation
sites for the land application alternatives. The Forest Beach parcels
(rapid infiltration alternative) are located contiguous to the Shipyard Planta-
tion lagoon system. Within the Gardner-Matthews tract there are freshwater
wetland areas which must be considered during layout of the irrigation system.
III-2
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For the wetlands discharge system under all five alternatives, there is
a possibility that wastewater could eventually reach Lawton Canal, dependent
upon points of release, rates of application, and hydrologic conditions.
Impacts should be minimal because of the additional treatment which would
be afforded to the applied wastewater during its passage. The wetlands
discharge system could have a major beneficial impact on water levels within
the Forest Preserve. Periods of drought and diversion of natural recharge
have dried up many wetlands areas within the Preserve thereby altering the
natural habitat.
The quantity of water in Lawton Canal will increase from a direct dis-
charge CLawton Canal alternative) or from lateral recharge from the rapid
infiltration system (rapid infiltration alternative). Increased flow in
lagoons and other inland water bodies could result from runoff and/or lateral
recharge from the three land application alternatives.
2. GROUNDWATER RESOURCES
There is inconclusive evidence that Hilton Head Island is a recharge
area for the principal artesian aquifer which serves as the primary source
of water for users on the island. The first evidence that Hilton Head Island
is a recharge area surfaced in 1970 in a paper by Back, Hanshaw, and Rubin.
They showed that groundwater levels had stabilized at the zero potentiometric
contour positioned around the center of the island, while to the north and
south, the groundwater level declined.
More recently, both the South Carolina Water Resources Commission and
the South Carolina Department of Health and Environmental Control have con-
ducted well tests that show that there is 100 percent sand from the top of
the soil down to the aquifer. No confining clay layer covers the aquifer.
The top of the principal artesian aquifer ranges from about 80 feet below
msl in the extreme north end of the island to about 120 feet below msl in
the southern end of the island.
Potential impacts to groundwater resources are greatest from the rapid
infiltration alternative because the rapid infiltration system will remove
nitrogen from the applied wastewater to a much lesser extent than any other
land application techniques. Additional nitrogen removal at the Sea Pines
PSD plant would be required should groundwater monitoring indicate that
nitrate contamination of the aquifer was occurring.
Substantially lesser impacts to the groundwater are expected from the
proposed woodlands irrigation systems because they will result in more
complete renovation of the applied wastewater. Wando soils pervade the
Gardner-Matthews site. Depth to groundwater appears adequate, although
detailed soils investigations have not yet been conducted.
Rapid infiltration, woodland irrigation, and/or wetlands discharge
will result in the recharge of the Hawthorn Formation. Spray irrigation to
the golf courses, which is a part of all the alternatives, will decrease
III-3
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the demand for groundwater for irrigation. This will also result in re-
charge of the groundwater aquifer system as well as reduced demand for
pumping. The surface water discharge alternatives will have no adverse
impact on groundwater quality. However, these alternatives will not pro-
vide for the reuse of treated wastewater as a beneficial resource.
3. ECOLOGICAL RESOURCES
Land application systems would result in a greater adverse impact to
terrestrial ecosystems on Hilton Head than would alternatives relying on
discharge to surface waters.
The Gardner-Matthews site can be characterized as an upland forest
which is predominately mixed hardwood with some pine. The total site is
composed of between 5 and 10 percent wetlands. The Union Camp site on the
mainland is predominately pine forest. The Shipyard Plantation spray ir-
rigation sites (component of the rapid infiltration alternative) are also
wooded.
Clearing would be required for installation of woodlands irrigation
systems under the land application alternatives, thus resulting in some
habitat alteration. Impacts would be minimized through the use of solid-
set spray systems rather than center pivot systems. In addition, wood-
lands irrigation would cause shifts in vegetation and wildlife composition
toward species which are more water-tolerant. Such impacts are difficult
to classify as beneficial or adverse unless net reductions in diversity,
productivity, abundance, or protected species occur.
Disruption of beach communities would occur during installation of
the Calibogue Sound outfall across South Beach. This crossing will also
impact nesting areas for least terns and the threatened loggerhead turtle
depending on the timing of construction activities.
Construction of the rapid infiltration system would result in the
permanent loss of over twelve acres of wildlife habitat within the Forest
Preserve; construction of the 8-acre holding pond at the Gardner-Matthews
site or at the off-island site would also result in a permanent loss of
wildlife habitat.
The wetlands discharge system, which is incorporated into each al-
ternative, will restore the natural habitat within the Forest Preserve
and should be conducive to the maintenance of wetland communities. Improved
habitat conditions could result for protected species such as the American
alligator. However, adverse impacts may be incurred because of effects on
two wading bird colonies known to exist in the Preserve. Studies of bird
populations at cypress dome wetlands in Florida have shown dramatic de-
creases in habitat usage by wading birds (Better 1975; Jetter and Harris
1976) coincident with the introduction of treated wastewater.
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4. AQUATIC SYSTEMS
Estuarine waters comprise the primary aquatic system of the Hilton
Head study area. Included within the ostuarine system are tidal creeks,
coastal bays and sounds, river mouths, and tidal marshes and flats. A
freshwater system may also be recognized, but it is limited in extent and
largely inter-grades with the freshwater wetland plant communities on
Hilton Head Island.
Adverse impacts to aquatic ecosystems will result from alternatives
involving a discharge to surface waters. In particular, the South Carolina
Wildlife and Marine Resources Department has expressed concern regarding
any discharge to the marine environment.
Discharge to Calibogue Sound would result in a localized decrease in
the diversity of benthic communities along the subaqueous outfall and dif-
fuser. Increased biological productivity would result from nutrient load-
ings and likely be channeled into one of several opportunistic animal
species. However, with proper location and design of the diffuser structure,
these impacts should be minimal.
Discharge to Lawton Canal would also result in impacts to the aquatic
ecosystems. These impacts would be expected to be lesser than those from
unabated non-point source runoff. Stream bed erosion along Lawton Canal
from the increased volume of discharge could increase turbidity and disrupt
benthic communities.
The continued use of chlorine as a disinfectant poses concerns regard-
ing potential impacts to the aquatic ecosystems for discharge into either
Lawton Canal or Calibogue Sound. Dechlorination or alternate methods of
disinfection could minimize this adverse impact.
There are also several areas of concern with respect to the wetlands
discharge system which is part of each alternative. The introduction of
treated wastewater into the Forest Preserve could produce anaerobic condi-
tions resulting in significant changes to the faunal community. In addition,
the elevation of nutrient levels could result in significant changes in the
plant community with potential for algal or duckweed blooms. The controlled
experimental program which is being implemented by the Sea Pines PSD will
provide valuable information with respect to these potential impacts. Field
investigations should be performed in order to establish baseline conditions
against which possible changes can be monitored.
Wetlands comprise approximately 45 acres (less than 5 percent) of the
Gardner-Matthews site. Two wading bird colonies exist near its periphery.
Major adverse impacts could result if these environmentally-sensitive areas
are significantly altered or disturbed. Such impacts should be able to be
avoided because of the large amount of uplands at the site and the peripheral
location of the bird colonies and most of the wetlands.
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5. POPULATION AND LAND USE
Selection of the land application alternatives would eliminate these
currently undeveloped tracts of land as potential areas of settlement for
population growth in the future. The projected needs for Sea Pines - Forest
Beach would be approximately 500 acres for spray irrigation on the Gardner-
Matthews or the off-island tracts. Current development plans for the Gardner-
Matthews site will call for about 3800 units on 1800 acres of land which
averages out to slightly more than two units per acre. The owners of the
land could increase densities on the remainder of the tract to make up for
the land which would be used for spray irrigation. Therefore the total
number of people living on the site would not change.
The spray irrigation component of the rapid infiltration alternative
would take 67 acres out of potential use for future development in Shipyard
Plantation. It is expected that the area would be developed as residential
property. Current master plans call for multi-family villas on the Shipyard
site.
The wetlands application proposed for the Sea Pines Forest Preserve will
not alter the land use specified for this area in the property covenants.
According to the Sea Pines Master Plan, this area has been planned to re-
main in its natural state.
6. ECONOMICS
The Lawton Canal alternative will increase the area closed to shellfish
harvesting in Broad Creek due to the necessity for the enlarged buffer zone.
This will decrease the potential harvest in the lease area as shown previously
in Plate ES-1. This action would be a continuation of the long-standing
trend of closures of shellfish harvesting areas in Broad Creek for marinas
and because of non-point source problems.
The Calibogue Sound alternative would not cause the closing of any
shellfish harvesting areas. Although the discharge area is officially classi-
fied as SA waters, there are no active leases in the area which would be in-
cluded in the buffer zone. Many local residents have expressed the concern
that the implementation of this alternative would be harmful to the fishing
industry in general. EPA can not substantiate these concerns. A further dis-
cussion is presented in the water quality section of this chapter.
The cultural aspect of the local fishery has been considered in the EIS.
Most of the people employed by the seafood industry around Hilton Head are
low income blacks. Loss or degeneration of the fisheries could have a major
impact on them as well as a number of white families, both of whose fishing
heritages have been passed down from generation to generation. The loss
would cause not only an economic impact but the displacement of a people whose
way of life can not be valued in monetary terms.
III-6
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The value of the fishery to the island developers and to the tourist
trade has also been considered. People have been attracted to Hilton Head
because of its mild climate, pristine waters, excellent sportfishing and fine
local seafood restaurants. Consequently, degeneration of the fishery by
pollution of local waters could adversely impact much of Hilton Head's
appeal and could possibly reduce property values.
South Carolina DHEC indicates that no buffer zones would be required
as a result of the implementation of any of the land application alternatives.
The implementation of any of the alternatives will result in the creation
of construction related jobs. There is no significant difference among the
alternatives in the degree of this impact.
The implementation of the land application alternatives would eliminate
these sites from future development. This would involve approximately 500
acres at the Gardner-Matthews or the off-island site and 67 acres at the
Shipyard Plantation site under the rapid infiltration alternative.
7. ARCHEOLOGICAL AND HISTORICAL
Archeological surveys would be required to document potential impacts of
all alternatives except Lawton Canal. The greatest potential impacts are
related to the land application alternatives.
8. NOISE
Construction related impacts would come from plant upgrading, installa-
tion of force mains including highway tunneling, and site preparation at land
application sites. These impacts would be the smallest for the Lawton Canal
alternative since the smallest amount of construction would be involved and
this construction would be limited to the area of the existing site. None of
the noise impacts associated with any of the alternatives is expected to be
significant.
PART C. SECONDARY IMPACTS
Population growth has proceeded rapidly on Hilton Head Island for the
last several years and all indications are that this trend will continue in
the future. JPC and OBERS population projections are presented in Tables III-l
and III-2 respectively. The JPC population projections presented in Table III-l
represent an increase of approximately 230 percent over present levels by
the year 2000. An increase of this magnitude will cause severe strain on all
aspects of the natural and manmade environments.
III-7
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TABLE III-l
DISAGGRECATION OF YEAR 2000
POPULATION FOR HILTON HEAD ISLAND
JPC BASE
00
Service Area
Sea Pines PSD
Forest Beach PSD
Broad Creek PSD
Hilton Head No. 1 PSD
Hilton Head Plantation
Long Cove Club
Non-PSD
Permanent
Residents
11,327
3,951
1,976
2,581
2,713
1,238
2,555
Overnight
Visitors
6,245
6,428
3,752
3,163
466
0
223
Off- Is land
Employees
2,074
2,068
1,573
1,585
1,359
187
968
Seasonal
Residents
975
2,200
1,440
875
480
50
90
Day
Visitors
375
475
240
475
90
60
210
Total
20,996
15,122
8,981
8,679
5,108
1,535
4,046
Total
26,341
20,277
9,814
6,110
1,925
64,467
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TABLE III-2
DISAGGREGATION OF YEAR 2000
POPULATION FOR HILTON HEAD ISLAND
OBERS BASE
Service Area
Sea Pines PSD
Forest Beach PSD
Broad Creek PSD
Hilton Head No. 1 PSD
Hilton Head Plantation
Long Cove Club
Non-PSD
Permanent
Residents
9,443
3,294
1,647
2,152
2,262
1,032
2,130
Overnight
Visitors
7,364
7,579
4,423
3,730
550
0
263
Off- Is land
Employees
842
838
632
642
550
62
387
Total
17,649
11,711
6,702
6,524
3,362
1,094
2,780
Total
21,961
23,909
3,953
49,823
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Although all the alternatives discussed in the EIS will provide service
for the JPC capacity, the disposal option that is implemented will have a
significant impact on the ultimate population of the Island. This ultimate
population will directly affect the demand for the area's community services
and facilities as well as impact the natural environment.
Ultimate capacities for residential units within the Sea Pines PSD area
are limited by restrictive covenants in the deeds of the homeowners. However,
hotel type developments, both in the Sea Pines PSD and the Forest Beach PSD,
are not limited. No legal constraints exist elsewhere on the Island which
could effectively be used to limit population density.
Increased population levels would be harder to support under the land
application alternatives due to the need to buy more land in the future. This
would be especially applicable for the on-island land application alternative
due to the constantly increasing land costs and decreasing availability of
land. These alternatives would create a perception of a wastewater disposal
system which was limited in nature. Developers would be inclined to keep
densities low to insure that disposal capacity was available either with a
PSD or on their own land.
The wastewater disposal alternatives involving surface discharges would
be more flexible regarding increasing capacities in the future. Only increased
plant capacity, pumping capability through the outfalls, and increased NPDES
permit limitations would be required. Developers would no longer consider
wastewater disposal as a serious constraint to development and would tend to
plan developments with higher densities.
The alternative which limits the provision of Federal funds based on con-
trol of non-point source pollution and the no-Federal action alternative will
not affect ultimate population density based on the potential lack of Federal
funds. Market conditions are such that developers will assist the PSD's in
financing the cost of these alternatives if necessary. This type of arrange-
ment has already occurred in some instances on Hilton Head.
The remainder of this section discusses the secondary impacts of the
population levels which will result from the various alternatives upon each
aspect of the manmade and natural environments.
1. LAND USE
With the construction of the Byrnes Bridge in 1956, development began
according to the resort plantation concept. Plantations are best described
as large-scale planned unit developments which combine residential and open
space/recreation land uses and occasionally include shopping facilities and
restaurants. Approximately 30 percent of the Island's 42 square miles have
been developed as shown in Plate 111-2. The south end of the Island is more
intensely developed than the north end. Table III-3 shows the land uses
occupying the island's 27,954 acres and the percent utilization of each land
use category.
111-10
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TABLE III-3
HILTON HEAD ISLAND
SUMMARY OF EXISTING LAND USE BY ACRES AND PERCENT USE
Land Use
Residential
Single Family
Multi- Family
Mobile Home
Commercial
Industrial/Utility
Open Space/Recreation
Institutional/Public Facility
Cemetery
Transportation
Streets, alleys, roads, utility rights of way
Forest/Agriculture
Total Developed Area
Undeveloped Area
Vacant
Marsh
Water
TOTAL:
Acres
4,365
3,253
796
316
319
31
3,716
160
25
1,090
214
9,920
18,034
13,052
4,308
674
27,954
Percent
15.6
11.6
2.8
1.2
1.1
0.1
13.3
0.6
0.1
5.9
0.8
35.5
64.5
46.7
15.4
2.4
100.0
Source: Beaufort County Joint Planning Commission, 1981.
III-ll
-------
As shown in Table III-3, 13,052 acres (46.7 percent) are classified
as vacant land and can be considered to have development potential, subject
to detailed engineering surveys. The rate and location of future develop-
ment on the island will come about in response to private market conditions
and the availability of public and private utilities.
Approximately 17,500 acres of the island's 28,000 acres (63.0 percent)
are currently owned by the plantation developers, all of whom have filed
masterplans with the JPC. Estimates of the number of dwelling units to be
eventually constructed can be derived from these masterplans with reasonable
accuracy. Table III-4 displays these data. With the possible exception of
Sea Pines Plantation, none of the plantations is expected to be fully built
out by the year 2000. Plate III-3 shows plantation locations.
The remaining 10,500 acres are owned by individuals or non-plantation
developers, and approximately 25 to 30 percent of this land is currently
developed. Because these areas are not masterplanned, it is extremely
difficult to predict their rate of development and ultimate land uses. A
portion of this land will be converted to villa and multi-family uses. Com-
mercial development will increase along Highway 278 in response to population
growth as shown in Table III-5. Much of the new commercial development will
take place at the northern end of the island to serve a growing resort and
residential base in that area. Future land use is shown in Plate III-4.
Much of the undeveloped non-plantation land located in the northern
half of the island is known as Heir's Property (see Plate III-3). These
tracts date back to the allocation of 40-acre parcels to black families
during Reconstruction. During the past hundred years, these tracts have
passed with divided and undivided interest to the heirs of the original
property owners. In many instances, titles are now unclear, and the task
of assembling parcels into large enough tracts to warrant significant develop-
ment is too cumbersome. Thus the development potential of Heir's Property
is severely constrained at this time. The black community's difficulties
encountered in participating in the capital appreciation of the island's
land has had social and political repercussions.
In addition to title problems, most of the Heir's Property is not served
by a Public Service District and consequently is unsewered. Thus, Heir's
Property land will continue to remain in low density residential uses until
such time as sewer service is available and the land becomes attractive to
developers. The capital costs of providing wastewater management services
to these areas and the ability of the population served to meet connection
fees and user charges is a significant concern of black community leaders.
Both existing and future land uses are discussed in greater detail in
the Environmental Inventory Task Report which is provided as a Technical
Reference Document. Table III-6 summarizes the most recent findings of the
JPC Land Use Plan study. Multi-family units are expected to incease from
approximately half of the existing housing stock to two-thirds of the future
housing inventory, leading to greater densities per developed acre.
111-12
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TABLE II1-4
HILTON HEAD ISLAND
PLANTATION DWELLING UNITS AT BUILD OUT
Plantation
Windmill Harbor
Hilton Head
Palmetto Dunes Highlands (1)
Gardner-Matthews
Port Royal
Spanish Wells
Shelter Cove
Palmetto Dunes
Long Cove Club
Long Cove Plantation
Shipyard
Sea Pines
Single-Family
56
2530
1231
722
849
189
1101
650
382
351
3790
11,851
Multi-Family
414
3420
1368
3472
122
1401
3500
200
143
1119
2100
17,259
Hotel
450
760
341
494
2,045
(1) Estimated
Source: Beaufort Joint Planning Commission, Sea Pines Company, EMRO Land
Company, Hilton Head Plantation, Palmetto Dunes Resort
111-13
-------
-------
TABLE II1-5
HILTON HEAD ISLAND
EXISTING AND KNOWN PLANNED COMMERCIAL
ACREAGE AND ESTIMATED RETAIL FLOOR AREA
Commercial Estimated Floor
Type of Development Acreage AreaOSquareJeetl
1,433,250
>
. .
Existing
256.5 1,154,250
Known Planned
TOTALS 575.0 2,587,500
Source: Beaufort Joint Planning Commission development files and
projections, 1981.
111-14
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-------
TABLE III-6
HILTON HEAD ISLAND
EXISTING, KNOWN PLANNED, AND ESTIMATED ISLANDWIDE
BUILD OUT OF RESIDENTIAL AND HOTEL
CONSTRUCTION(1)
Type of Dwelling Existing
Known Total
Planned Estimated Build Out
Single Family
4,461 (33.5) 8,623
4,025 17,109 (29.7)
Multiple Family
7,289 (54.8) 16,265 14,441 37,995 (66.0)
Hotel Rooms
1,557 (11.7)
894
2,451
(4.3)
TOTAL
13,307 (100.0) 25,782 18,466 57,555 (100.0)
(1) Based on master plans or plats approved by JPC. Does not include existing
823 units of manufactured housing.
Source: Beaufort Joint Planning Commission development project files and
projections, 1981.
111-15
-------
Hilton Head Island is part of unincorporated Beaufort County and subject
to the County's development controls. The Cities of Beaufort and Port Royal
have adopted zoning ordinances, but the County has not. Currently, there is
no zoning on Hilton Head Island.
The nature and the pace of future land use development on the island
is essentially left to market forces. This will continue to be the case
until local government completes the land use planning process and initiates
meaningful development controls. The removal of wastewater treatment and dis-
posal as a constraint to development in the Sea Pines - Forest Beach area
would have a significant impact upon the conversion of undeveloped land to
more urban land uses. The implementation of any of the alternatives would
support development patterns as shown in Plate III-4. Market conditions may
lead to pressures for higher density land uses than those forecast in the
future land use plan. The wastewater disposal alternatives involving sur-
face discharges would lend themselves most to increasing capacities in the
future. Increased plant capacity, pumping capability through the outfall
and increased NPDES permit limitations would be required. Increased land
use densities would be harder to support under the land application alterna-
tives due to the need to buy more land. This would be especially true if
the on-island land application alternative is selected due to the constantly
increasing land costs and decreasing availability of land. Land is cheaper
and more available off-island. However, extensive pumping costs are involved
which would increase with the distance from the island. This distance can
be expected to increase as development near the island increases.
The portion of the Sea Pines - Forest Beach area most sensitive to
future development pressure is the oceanfront in Forest Beach. More hotel-
motel and residential high-rise development will be constructed as market
conditions allow. No land use controls currently exist which would stop this
type of development nor the 1300 wheeled-in modular stacked units on the
beachfront north of Palmetto Dunes Resort.
The method of disposal selected for Sea Pines will also impact land use
in other areas of the island. The implementation of a surface discharge
alternative would set a precedent for a similar discharge into Port Royal
Sound. This would make it easier for developers to build at higher densities
without being concerned with adequate land being available for spray irriga-
tion This will be especially true for the many small land holders in the
northern part of the island who would be heavily impacted by wastewater
disposal constraints due to their lack of readily available land and capital.
2. ECONOMICS
Implementation of any of the alternatives will support extensive economic
activity throughout the 20-year planning period. The expected continued high
growth rate will especially benefit the construction and real estate industries
An increased variety and number of job opportunities will be present for
those people already living on the island. The lack of affordable housing
for low and moderate income groups will increase the number of off-island
employees who will require higher salaries to offset commuting costs.
111-16
-------
The oss of employment in the shellfishing industry due to closing of
beds resulting from non-point source pollution will continue unless appropriate
Fed^Tf T^ C°ntr01 meaSUreS ^ imPleme»ted. The alternative making
Federal funding contingent upon the development of a plan to control non-point
source pollution would encourage the solution of this problem Se surface
discharge alternatives have the greatest potential for supporting development
beyond the projected year 2000 population. This would incase the magnitude
of the impacts discussed in this section magnitude
3. TRANSPORTATION
If population projections are accurate, the capacities of the roadwav
systems on Hilton Head will be exceeded well before the year 2000 based upon
evaluations presented in the "1975 Hilton Head Island Thoroughfare Plan" "
prepared for the Beaufort County Planning Commission. The projections in the
- "
an
- Capacity of a proposed four-lane bridge over Skull Creek (first two
ornse:on°:hrred:ftC"StrUCti0n) ^ "' reaChed in ^-i-tely 1995^°
°" P°pe Avenue and Sea Pines a"d Coligny Circles
lnCreaSinS Congestion as commercial development
Three alternatives were presented for alleviating the Highway 278 con
divid^V^eSe 'T^ Cl) uP^adi"g of Highway 278^0 a six- lane at -grade
divided highway; (2) upgrading of existing four-lane Highway 278 to a ffeewav/
parkway with on/off ramps to provide for limited accessf or C3) construction
m,hw^W77rr"lan| M?hra7 aCr°SS Hilt°n Head Island wh^h would depart from
Highway 278 near Spanish Wells Road, overpass Spanish Wells and Otter Hole
Roads, cross Broad Creek, and terminate at Palmetto Bay Road
network ^hir"" ^ the.future improvements needed for the major arterial
ir-p-..
-
not only for
111-17
-------
overload the existing highway network on Hilton Head Island. The timing
of required improvements must be periodically reviewed in light of actual
population increases and resulting traffic.
The surface discharge alternatives have the greatest potential for
supporting development beyond the projected year 2000 population. This
would increase the magnitude of all the impacts discussed in this section.
The greater potential densities allowable under these alternatives would
create more localized bottlenecks as well as more islandwide congestion.
The lower densities which would result under the land application alternatives
should mean less congested traffic intersections as well as less ultimate
overall island traffic.
4^ COMMUNITY SERVICES AND FACILITIES
The anticipated growth on Hilton Head Island will place an increased
demand on community facilities and services. Currently, fire protection,
libraries, and health care are considered fully adequate. Therefore, the
expansion of these services to meet new levels of population needs only to
be made in proportion to population gains. However, concern has been ex-
pressed over the adequacy of public education facilities, police protection,
and public recreational opportunities.
Public education is presently deemed inadequate. A $16.25 million
county-wide school bond issue was authorized in early 1980; $8 million of
the bonds were sold in late 1981. The remaining $8.25 million is scheduled
for sale in March of 1982. Opening of the new school is now expected in
the fall of 1983. The inadequate quality of education as well as the physi-
cal condition of school facilities has been a major issue in the community.
The majority of new island residents will belong to upper income groups. Their
expectations as to what constitutes high quality public education will cause
per capita spending and individual taxes to increase in order for their require-
ments to be met.
Police protection is also considered unsatisfactory at present. Although
more deputies have been added to the Beaufort County Sheriff's Department in
1980, islanders remain concerned about steadily rising crime rates, traffic
conditions, and congestion. These trends will continue in the face ofjapid
urbanization unless service levels are increased significantly Thus Dividual
taxes can be expected to increase to cover the costs of new buildings, equip-
ment, and personnel.
Although the development of Hilton Head Island has been resort-oriented
since the early 1950's publicly-financed facilities on the island do not
meet the needs of those who cannot afford private recreation °PPortunitics
For example, the island contains no public golf courses no pub ^ ^m™5^
and no public campground. Limited access and support facilities have affected
the use of public beach areas. Population increases will generate a demand
for additional marinas. Both the construction and PP6™^0*™™""^
cause significant adverse environmental impacts without the ^^f.^"0/
proper controls addressing initial and maintenance dredging, the flushing ot
bilges and sanitary facilities, fuel spills, litter control around concessions,
etc Water quality degradation and loss of aquatic habitat are major areas of
impact.
111-18
-------
In summary, the significantly expanding island population will demand
an increase in the quantity of all services and in the quality of selected
services. Pressures are now mounting for either greater responsiveness to
island needs from Beaufort County or some alternative form of government.
Since island population is projected to increase more rapidly than other'
districts in the county, these pressures are expected to continue. Increased
local taxes will almost certainly result from any significant expansion in
services and facilities.
These needs in expansion of services and facilities discussed above will
result from the projected JPC population forecast for the year 2000 which
will be supported by all the alternatives being evaluated. The lack of land
use controls means that the rate of development under any alternative will
be controlled by market forces rather than geared to the provision of adequate
services and facilities. This will drive up the cost to local government to
pay for the additional services and facilities.
Additional impacts to Hilton Head community services and facilities would
result if greater population levels than those in the JPC projections are
realized. These higher levels would be more easily attainable if the surface
water discharge alternatives were chosen for the reasons discussed in the in-
troductory section of this chapter. Very crowded conditions could be the
result of higher population levels with higher taxes necessary to correct
these conditions.
5. WATER QUALITY
Recent water quality studies by DHEC have confirmed that non-point source
pollution of the Lawton Creek - Broad Creek waters is significant. Sub-
standard water quality conditions have been shown to be attributable in
large part to bacterial contamination from non-point source runoff These
water quality problems will persist until such time as effective non-point
source controls are implemented. Adjacent water bodies such as Point Comfort
Creek, Baynard Creek, and Braddock Cove are vulnerable to the same problems
in the near future as the southern end of the island maintains its existing
development momentum.
The waters of Jarvis Creek, Old House Creek, Skull Creek, and Fish Haul
Creek are also susceptible to non-point source pollution as the northern end
of the island develops. Little is presently known about water quality in these
creeks. Unless baseline studies are conducted in the near future while these
areas are relatively undeveloped, public agencies will not be able to assess
the significance of future water quality changes and take action to control
specific sources of pollution.
Unless appropriate non-point controls are implemented, additional closures
o± SA waters can be expected as development proceeds on the island Those
alternatives allowing the greatest ultimate population density have the potential
for causing greater adverse impacts to the SA waters. Therefore, the surface
water discharge alternatives offer the greatest potential for adverse impacts
to water quality due to greater quantities of runoff generated than the land
application alternatives.
111-19
-------
The only alternative which encourages any improvement in the non-
point source situation is the Federal funding conditional on non-point source
solution alternative. As part of the alternative, no Federal funds would
be provided to Sea Pines PSD unless action is taken to mitigate the non-
point source problems in that area.
PART D. MITIGATIVE MEASURES
Measures are suggested below to mitigate the adverse impacts which
have been previously identified. Most of these measures are the responsibility
of the local government in Beaufort County.
1. SURFACE WATER QUALITY
- Use of alternate means of disinfection to chlorination if a disposal
to surface waters is selected.
- Development of a more extensive water quality baseline of the entire
island so that data exist against which to measure future water quality
changes and assess significance of changes. A more active water quality
role by DHEC is required.
- Renovation of known failing septic fields, early identification of
incipient failures, and proper installation of future on-lot systems.
More supervision and enforcement of regulations by the County Health
Department is required.
- Better buffering of surface water bodies from lawns and other areas
which receive applications of herbicides, pesticides, and fertilizer.
- Control of runoff from horse pastures and other animal confinements.
- Improved litter control and solid waste management.
- Control of discharges from bilges and sanitary facilities of com-
mercial and pleasure boats, particularly within estuarine and marine
waters. More stringent enforcement of Coast Guard regulations.
- A policy by local regulatory bodies to discourage the construction
of new marinas in shellfish waters.
- Consideration of using naturally occurring wetland areas to receive
and assist in renovation of urban runoff.
- Implementation of future recommendations of the Hilton Head Island
208 Non-Point Study and the Hilton Head Land Use Plan.
111-20
-------
2. SURFACE WATER QUANTITY
- Requirements for on-site detention in new developments.
- Relief of localized flooding of unpaved roads at the north end of
the island. Drainage improvements should be made by the County Public
Works Department. Such activity should be planned very carefully as
additional non-point source pollution may result.
5. GROUNDWATER QUALITY AND QUANTITY
- Continued expressions of interest by local community officials and
citizens in the development and findings of the Corps of Engineers'
Savannah Areawide Study which addresses the regional drawdown of potable
water supplies.
- Implementation of a water conservation program via public education
and changes to the plumbing code so as to decrease demand on the ground-
water resource.
4. TERRESTRIAL ECOSYSTEMS
- Vegetative survey on-site if spray irrigation alternative is
selected.
- Enforce regulations of the U. S. Army Corps of Engineers, the South
Carolina Coastal Council, and the Beaufort County Development Standards
Ordinance which restrict the development of wetlands, oceanfront beaches
and primary dunes.
- Utilize boardwalks for access in developed beach zones.
- Strengthen the Development Standards Ordinance until such time as
it is replaced by a Land Use Plan.
- As new plantations are developed, encourage measures such as nature
preserves/conservancies, greenbelts, buffer zones, and tree ordinances
which help maintain natural habitat conditions.
- Minimize unneccesary clearing of trees and other vegetation in
developed areas.
5. AQUATIC ECOSYSTEMS
- Protection of wetlands and waters by existing legislation as well
as avoidance of lowering water levels by alteration of natural drainage
patterns.
111-21
-------
- Control of leachate from dredge spoil.
- Implementation of previously discussed mitigative measures affecting
surface water quality.
6. POPULATION
- Implementation of local controls to plan population densities on the
island consistent with local community development goals.
7. LAND USE
- Strengthening of the Development Standards Ordinance to control building
densities within a site and to promote the provision of open space.
- Adoption of a Land Use Plan to control strip development along Highway
278, regulate densities, buffer incompatible land uses, and regulate
nuisances.
CULTURAL RESOURCES
- Archeological survey of land impacted by selected alternative.
- Control of non-point runoff as described under Surface Water Quality
to protect shellfish supplies.
- Support of fishing coops and other programs to broaden shellfish
markets.
9. RECREATION
- A more active role by citizens and island representatives in the
preparation of the County's capital budget to provide for public
recreation.
- Cooperation between JPC staff and oceanfront developers to provide
public access easements to beaches where possible.
- Control of non-point runoff as described under Surface Water Quality.
111-22
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10. TRANSPORTATION
- Consideration of a public transportation system.
- Upgrading of unpaved county roads.
- Provision of bikeway systems and sidewalks.
- Increased and more efficient signalization.
- Initiation of Mackay Creek Bridge improvements.
11. COMMUNITY SERVICES AND FACILITIES
- Coordination of detailed community facilities planning with controls
of rate of population increase and land use planning.
- Adequate funding of island needs by county government or an alternate
form of government.
- Hiring of additional Sheriff's Deputies.
- Neighborhood watch programs and other citizen self-help efforts
for crime prevention.
- Implementation of the Rural Water Authority proposal to improve fire
protection services.
- Greater enforcement of regulations against illegal construction
dumps.
- Expanded pick-up services for trash and garbage collection.
111-23
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-------
CHAPTER IV
DESCRIPTION OF THE PREFERRED ALTERNATIVE
-------
-------
CHAPTER IV
DESCRIPTION OF THE PREFERRED
ALTERNATIVE
PART A. INTRODUCTION
The purpose of this EIS is to select a wastewater management program for
Hilton Head Island that is compatible with the protection of the area's sensi-
tive resources, particularly water quality. At the same time, the selected
alternative must consider the extensive development pressures on the island
and their potential impact on the natural and manmade environment.
The EIS has determined that discharge to Calibogue Sound, spray irrigation
on-island, and spray irrigation off-island are all environmentally acceptable
alternatives for the Sea Pines PSD - Forest Beach PSD. Also, during the course
of the EIS, extensive analysis of water quality data indicated that non-point
source pollution from stormwater run-off is a severe problem.
In light of these findings, EPA has decided to condition Federal funding
of the most cost-effective disposal alternative that can be implemented locally
upon the development of a non-point source control program within the two PSD's.
PART B. SEA PINES PSD - FOREST BEACH PSD
The preferred wastewater management program for Sea Pines PSD - Forest
Beach PSD is the most cost-effective, implementable alternative of the three
environmentally acceptable disposal options - discharge to Calibogue Sound,
spray irrigation on-island at Gardner-Matthews, or spray irrigation off-
island. Permits issued by the Army Corps of Engineers, the Coastal Council,
and DHEC would be necessary for the Calibogue Sound alternative to be imple-
mentable. Implementation of any one of these alternatives will remove the
existing discharge from Lawton Canal thereby eliminating the need to enlarge
the required buffer zone for shellfishing and eliminate the need to rely upon
rapid infiltration as a land application technique thus minimizing impacts to
the groundwater.
Construction of wastewater facilities (Step III) would be eligible for
Federal funding if an effective non-point source program were developed and
implemented for the Sea Pines PSD - Forest Beach PSD area by the time the
Step II design phase was complete.
IV-1
-------
Detailed studies will be required during Step II to determine the
optimal location and orientation of the outfall/diffuser structure into
Calibogue Sound. If either of the spray irrigation alternatives are im-
plemented, site specific studies will be required to determine the layout
of the system and recommended application rates.
If Federal funding is made available for Step III construction, facili-
ties sized to handle the 1.8 mgd now being discharged into Lawton Canal would
be eligible. Any additional disposal capacity constructed would have to be
funded entirely at the local level, in accordance with Federal and State fund-
ing procedures.
1. DESCRIPTION OF ALTERNATIVE
New facilities which would be required for each of the three environ-
mentally acceptable wastewater management alternatives are summarized in
Table IV-1. Treatment will be afforded by the Sea Pines PSD plant which is
now being expanded to 3.25 mgd with 100 percent local funding. Irrigation of
all five golf courses within the PSD's and the wetlands discharge system which
has already been approved in concept by the South Carolina DHEC and Coastal
Council will be used to the extent possible. Construction of these facilities
is being carried out entirely with local funds.
Sizing of the new facilities would be determined by the Sea Pines PSD -
Forest Beach PSD based upon their projection of ultimate build-out. Current
projections of the two PSD's indicate the need for an ultimate wastewater
treatment plant capacity of 5.0 mgd. However, any EPA participation in fund-
ing required wastewater facilities would be limited to disposal facilities
sized to handle the 1.8 mgd now being discharged into Lawton Canal.
2. COSTS
Cost information for the Calibogue Sound discharge, on-island spray ir-
rigation at Gardner-Matthews, and off-island spray irrigation were previously
presented in Tables II-8, 11-10, 11-11, 11-12, 11-14, and 11-15. A summary is
provided below.
Estimated Increase in Annual
User Cost
Net Present EPA Funding No EPA Funding
Alternative Worth
Calibogue Sound $ 1,818,300 $ 16.75 $ 40.69
Spray Irrigation $12,609,000 $117.26 $296.50
at Gardner-Matthews
Spray Irrigation $12,576,100 $108.59 $277.26
Off-Island
IV-2
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TABLE IV-1
SEA PINES PSD - FOREST BEACH PSD
DESCRIPTION OF FACILITIES REQUIRED
FOR ENVIRONMENTALLY ACCEPTABLE ALTERNATIVES
DISCHARGE TO CALIBOGUE SOUND
LAND APPLICATION ON-ISLAND
AT GARDNER MATTHEWS
LAND APPLICATION OFF-ISLAND
Pumping facilities at the Sea Pines PSD
plant;
Over 18,500 feet of force main from the
plant through Sea Pines Plantation and
across South Beach (alignment of force
main to be determined during Step II
design in order to minimize utility con-
flicts and traffic disruptions); and
Over 4,000 feet of subaqueous outfall
plus multi-port diffuser for discharge
of treated wastewater into Calibogue
Sound.
Pumping facilities at the Sea Pines PSD
plant to convey treated wastewater to the
Gardner-Matthews site;
Over 54,000 feet of force main from the
plant along Pope Avenue, Route 278,
Matthews Drive, and Marshland Road to
the site;
Purchase of sufficient acreage at the
Gardner-Matthews site to accommodate
wastewater quantities in excess of golf
course irrigation needs (estimated at
over 500 acres to provide for spray area
of approximately 305 acres plus adequate
buffer area);
Construction of a solid-set spray irri-
gation system at the Gardner-Matthews
site to provide for land application; and
- Pumping facilities at the Sea Pines PSD
plant to convey treated wastewater off-
island to Union Camp property (or to other
suitable sites that are available);
• Over 122,000 feet of force main from the
plant along Pope Avenue, Route 278, across
Skull Creek and Mackay Creek, and Route 278
on the mainland to the site;
Booster pumping station sited at optimal
location along force main route;
Purchase or long-term lease of sufficient
acreage at the Union Camp property to
accommodate wastewater quantities in excess
of golf course irrigation needs (estimated
at over 500 acres to provide for spray area
of approximately 305 acres plus adequate
buffer area);
Construction of an 8-acre, 23 million
gallon storage pond at the site.
Construction of a solid-set spray irrigation
system at the site to provide for land
application; and,
Construction of an 8-acre, 23 million gallon
storage pond at the site.
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3. IMPLEMENTATION
Implementation of the Calibogue Sound discharge will require permits
from the Coastal Council, Army Corps of Engineers, and an NPDES Permit from
DHEC.
Either of the two spray irrigation alternatives require that land out-
side the boundaries of the Sea Pines PSD and the Forest Beach PSD be obtained
either through outright purchase or condemnation. Based on current information,
neither Sea Pines PSD nor Forest Beach PSD has the power to purchase or condemn
land outside their respective boundaries. A recent opinion from the Office of
the South Carolina Attorney General indicates that the condemnation authority
of Beaufort County can be used to assist the PSD's in obtaining land for
spray irrigation. In-depth investigations will be required to determine
the best approach regarding ownership, management, and institutional arrange-
ments as they involve the County, the Sea Pines PSD, and the Forest Beach PSD.
As previously noted, EPA funding of the preferred alternative for the
Sea Pines PSD - Forest Beach PSD is dependent upon the development of a non-
point source control program within the PSD's. Under their present structure,
neither the Sea Pines PSD nor the Forest Beach PSD has the authority to
initiate or implement non-point source management programs. Implementation of
such a program will require the establishment of a new agency with appropriate
authority, or enactment of additional legislation by the Beaufort County Council
4. SPECIAL STUDIES
If the Calibogue Sound alternative is implemented, detailed studies will
be required during Step II design to determine the optimal location and
orientation of the outfall/diffuser structure into Calibogue Sound. These
studies should develop outfall and diffuser designs; alignment and depth of
discharge; and effluent plume location, mixing, and dilution.
If either of the spray irrigation alternatives are selected, detailed
field investigations will be needed to establish the physical, hydraulic, and
chemical properties of the soil. Groundwater depths must be determined,
and site inspections conducted to assess the existing vegetation and topo-
graphy. A monitoring program will be required to determine permissable loading
rates.
IV-4
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PART C. OTHER PSD'S
As previously indicated, the other PSD's are not eligible for Federal
funding based upon the OBERS funding formula. Therefore, any additional
wastewater facilities constructed by these PSD's (including Hilton Head
Plantation) must be done with 100 percent local funding. If proper planning
is undertaken now by these PSD's, wastewater facilities should be available
to meet future needs.
Septic tank-drainfield systems remain the preferred alternative for the
non-PSD areas where soils, groundwater depth, and site conditions are acceptable,
Solutions and costs for areas which experience malfunctions in the future will
depend on the extent of the problem area, the affected population, and develop-
ment plans for contiguous areas.
PART D. MITIGATIVE MEASURES
This section discusses activities which can reduce the magnitude of adverse
primary impacts from whichever Sea Pines PSD - Forest Beach PSD alternative
is implemented, as well as those activities which, if implemented by local
governing bodies, can reduce the secondary impacts caused by the continued
development of Hilton Head.
1. MITIGATIVE MEASURES FOR PRIMARY IMPACTS
Elements of the environment which are expected to be most greatly affected
include surface water quality, groundwater quality, terrestrial ecosystems, and
aquatic ecosystems. Measures which can be instituted during the design, con-
struction, and operation phases of the preferred alternatives for the Sea Pines
PSD - Forest Beach PSD to reduce the magnitude of adverse impacts to the environ-
ment are discussed below.
Surface Water Quality. Any water quality impacts which would result from a
discharge to Calibogue Sound can be further lessened from optimal location and
orientation of the diffuser structure based upon detailed current and circu-
lation studies. Potential chlorine toxicity problems from a Calibogue Sound
discharge can be avoided through dechlorination or the use of alternate methods
of disinfection.
IV-5
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Groundwater Quality. Judiciously placed groundwater monitoring wells of
varying depths can be used to determine impacts that might occur from either
of the spray irrigation alternatives. In the event that significant impacts
were determined, application rates could be lessened.
Terrestrial Ecosystems. Either of the spray irrigation alternatives will
result in impacts to terrestrial ecosystems. These impacts can be lessened
through conducting detailed site investigations so that sensitive environ-
mental areas can be located prior to layout of the woodlands irrigation
system. Any wetlands areas can thus be avoided, as well as any nesting
colonies. Baseline vegetational and wildlife conditions should be established
prior to system operation so that possible shifts in species composition can
be identified.
Construction of the pipeline crossing of South Beach for the Calibogue
Sound outfall should be scheduled to avoid the nesting season for least terns
(April - July) and for loggerhead turtles (late May - August).
Aquatic Ecosystems. Any impacts of a wastewater discharge to Calibogue Sound
will be considerably lessened through either dechlorination or by using other
methods of disinfection. For such a discharge, water quality and biological
monitoring programs should be established so that impacts of the discharge can
be assessed. Water quality monitoring would require that permanent stations
be established in the vicinity of the discharge point and that samples be
taken at regular frequencies. Biological monitoring could be accomplished
through means such as continuous, flow-through bioassays and the placement
of live boxes near the point of discharge.
Monitoring of the experimental wetlands discharge system which is already
being implemented should be accomplished in order to determine possible impacts.
2. MITIGATIVE MEASURES FOR SECONDARY IMPACTS
Non-point source pollution from continued development will impact the
island's water quality. Problems will grow continually worse if control measures
are not initiated now before development intensifies. Land use regulation and
implementation of non-point source controls such as on-lot retention and treat-
ment through natural wetlands systems could significantly mitigate non-point
source problems.
As previously indicated, EPA funding of wastewater facilities for the
Sea Pines PSD - Forest Beach PSD will be contingent upon development of
appropriate non-point source controls to alleviate existing problems and prevent
future problems within the PSD's. The 208 Non-Point Source Study, now underway,
is expected to recommend control measures for non-point source pollution. Many
of the recommendations will undoubtedly require that Beaufort County take a
firm position and require more stringent development controls through additional
legislation. These controls should be in effect for all development on the
island.
IV-6
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In addition, the Land Use Plan now being developed by the Beaufort County
Joint Planning Commission should be responsive to the needs of the island,
particularly in the planning for areas which lie outside the plantation
boundaries such as the Folly Field area, Forest Beach, and the Route 278 cor-
ridor. Additional controls may need to be implemented to enforce the recom-
mendations of the plan in order to mitigate the impacts related to population
growth of the island. More detailed community facilities planning and capital
budgeting by Beaufort County would likely be required to support the land use
and population projections in the land use plan.
The following are among the many measures which could be implemented to
lessen the impacts of future population growth on the natural and man-made
environment of Hilton Head. Most of these measures are the responsibility of
the local government in Beaufort County. The County should move to implement
these actions as soon as possible.
1. Surface Water Quality
- Development of a more extensive water quality baseline of the entire
island so that data exist against which to measure future water quality
changes and assess significance of changes. A more active water quality
role by DHEC is required.
- Consideration of using wetlands for urban runoff treatment.
- Control of discharges from bilges and sanitary facilities of com-
merical and pleasure boats, particularly within estuarine and marine
waters. More stringent enforcement of Coast Guard regulations.
- A policy by local regulatory bodies to discourage the construction
of new marinas in shellfish waters.
- Implementation of future recommendations of the Hilton Head Island
208 Non-Point Study and the Hilton Head Land Use Plan related to water
quality.
2. Surface Water Quantity
- Relief of localized flooding of unpaved roads at the north end of
the island. Drainage improvements should be made by the County Public
Works Departments. Such activity should be planned very carefully as
additional non-point source pollution may result.
- Implement future recommendations of Hilton Head Island 208 Non-Point
Study which will not have an adverse effect upon water quality.
3. Groundwater Quality and Quantity
- Continued expressions of interest by local community officials and
citizens in the development and findings of the Corps of Engineers'
Savannah Areawide Study which addresses the regional drawdown of potable
water supplies.
IV-7
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- Implementation of a water conservation program via public education
and changes to the plumbing code so as to decrease demand on the ground-
water resource.
4. Terrestrial Ecosystems
- Enforce regulations of the U. S. Army Corps of Engineers, the South
Carolina Coastal Council, and the Beaufort County Development Standards
Ordinance which restrict the development of wetlands, oceanfront beaches
and primary dunes.
- Strengthen the Development Standards Ordinance until such time as
it is replaced by a Land Use Plan.
5. Aquatic Ecosystems
- Implementation of previously discussed mitigative measures affecting
surface water quality.
6. Population
- Implementation of local controls to plan population densities on the
island consistent with local community development goals.
7. Land Use
- Strengthening of the Development Standards Ordinance to control building
densities within a site and ensure provision of adequate open space.
- Adoption of a Land Use Plan to control strip development along Highway
278, regulate densities, buffer incompatible land uses, and regulate
nuisances.
Recreation
- A more active role by citizens and island representatives in the
preparation of the County's capital budget to provide for public
recreation.
- Cooperation between JPC staff and oceanfront developers to provide
public access easements to beaches where possible.
IV-8
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9. Transportation
- Upgrading of unpaved county roads.
- Provision of bikeway systems and sidewalks.
- Increased and more efficient signalization.
10. Community Services and Facilities
- Coordination of detailed community facilities and capital
budgeting with land use planning.
- Adequate funding of island needs by county government or an
alternate form of government.
IV-9
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CHAPTER V
EIS COORDINATION
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CHAPTER V - EIS COORDINATION
PART A. INTRODUCTION
The purpose of this chapter is to document the interaction and com-
munications between EPA and its consultants with affected publics in the
study area. A wide variety of mechanisms have been employed: public
hearings, a Review Committee, informal small group meetings with officials
and private groups, letters, telephone calls, newspaper/radio/TV interviews,
and various types of handouts. An effort has been made to solicit input
from a wide spectrum of community interests, to keep each group informed
of study progress, and to bring together conflicting points of view.
The first sections of this chapter document concerns raised by public
bodies and private citizens. Thereafter, the public participation program
is described.
PART B. CONCERNS EXPRESSED BY OTHER PUBLIC AGENCIES OR INSTITUTIONS
A number of concerns have been expressed by state and local officials
as well as staff and commissioners of the Public Service Districts. This
section of Chapter V describes the major contributions and interests of each
group.
1. STATE AGENCIES
The South Carolina Wildlife and Marine Resources Department has expressed
concern with any disposal alternative which would result in a discharge to the
marine environment. The Department not only fears potential impacts but also
the precedent that such a determination might set. Areas of concern include
salinity alterations, changes in the species composition of the phytoplankton
community due to nutrient loadings, dissolved oxygen depletion, and the toxic
effects of chlorine and ancillary pollutants.
The South Carolina Coastal Council has also expressed reservations regard-
ing the discharge of treated wastewater into Calibogue Sound. The Council is
concerned regarding the proliferation of outfalls into marine waters, potential
impacts on aquatic ecosystems, and the conflict with the proposed mariculture
facility to be located at Victoria Bluff.
The South Carolina Department of Health and Environmental Control is
charged with the monitoring and the preservation of the SA (shellfishing)
designation of the waters surrounding Hilton Head Island. These waters include
V-l
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Lawton Creek, Broad Creek, Calibogue Sound, and Port Royal Sound. The Class
SA standards for shellfishing are very stringent and difficult to maintain.
For this reason, DHEC does not favor the discharge of treated wastewater to
shellfish waters where viable alternatives exist.
2. REGIONAL PLANNING AGENCY
The Low Country Council of Governments has stated that local government
must determine its objectives regarding land use and population and respond
accordingly.
5. LOCAL GOVERNMENT
Beaufort County has supported a coordinated approach to the study of
water supply, non-point source pollution and wastewater (point source) manage-
ment. The county is coordinating the 208 study. The major emphasis of this
study is the identification of drainage patterns, water quality sampling, and
the development of measures to control stormwater runoff.
4. PUBLIC SERVICE DISTRICTS
The following concerns have been raised during the course of the EIS
by representatives of one or more of the PSD's.
- Irrigation of golf courses with treated wastewater cannot be the
only alternative available to the PSD's. Backup alternatives are required
for use during rainy periods, during periods when the quantity of wastewater
seasonally exceeds golf course needs, and in cases where there are not enough
golf courses to handle projected wastewater flows.
- The EIS consultants have projected wastewater flows based on future
population assuming less than 100 percent occupancy rates. DHEC requires
that the PSD's project wastewater flows in terms of gallons per day per bed-
room of future dwelling units which assumes 100 percent occupancy.
- The PSD's project higher wastewater flows than the EIS, attributable
in part to the occupancy rate factor. The differences more drastically im-
pact wastewater management alternatives for the Broad Creek PSD and the Hilton
Head No. 1 PSD.
V-2
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PART C. CONCERNS EXPRESSED BY INDIVIDUALS AND PRIVATE GROUPS
A number of concerns have been expressed by individuals and private
groups. Many of these vary significantly from the concerns of public of-
ficials as well as from the concerns of other citizens. Some of the major
issues identified by individuals and private groups are listed below.
The EIS should determine the carrying capacity of the island's
environment and strictly control growth beyond those limits. The island needs
a population cap.
The EIS should control the non-point source pollution problems on the
island.
- The EIS is a waste of taxpayers' money. There is no reason to de-
vise expensive solutions to potential point source problems when it is known
that the current problem is non-point source pollution, which can only get
worse as the island continues to develop.
The revenues derived from development and tourism far outweigh the
revenues derived from the shellfish industry. Therefore, development should
not be unduly constrained in order to preserve SA class waters. Instead,
the oysters could be moved elsewhere for depuration.
- Because there is little chance that non-point runoff can be controlled,
SA waters should be reclassified to SB, and development should proceed within
that framework.
Population projections should follow historic trend lines rather than
OBERS disaggregations. OBERS figures are too low for the three population
components computed, and in addition, day visitors and seasonal residents are
omitted from OBERS calculations.
- Close liaison should be maintained with the Black Community to ensure
adequate consideration of their concerns.
- DHEC should establish a water quality baseline for the northern areas
of the island so that degradation trends can be identified as those areas are
urbanized.
- Closing of shellfish beds represents not only an economic loss but the
destruction of a longstanding way of life in the Black Community.
Widespread drainage problems have developed on the island as a re-
sult of extensive alteration to natural drainage patterns without regard for
upstream or downstream impacts. Water levels in the Forest Preserve wet-
lands have been lowered significantly. Standing water problems are found at
the north end of the island which cause road closings and may affect on-lot
disposal system efficiencies.
V-3
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- Questionnaires turned in at the land use and population workshops
rated protection of environmental quality as the No. 1 concern of island
residents.
PART D. PUBLIC PARTICIPATION PROGRAM
Public participation programs are mandated by federal regulations governing
the preparation of Environmental Impact Statements. Public participation is
an important and valuable part of the EIS process because it provides for active
public involvement in developing and evaluating wastewater management alternatives,
At the beginning of the Hilton Head Island EIS, a public participation
program was established to provide opportunities for interested groups, indi-
viduals, and government agencies,to participate in the development of the EIS.
ine focal point of this program was the establishment of a Review Committee.
Inis group served in an advisory capacity to EPA and their consultants. Specific
functions and duties of the group included:
- Identifying local planning and environmental objectives
- Identifying study area issues and conflicts regarding
wastewater management and environmental conditions
- Reviewing all task report submissions
- Assisting in the development and evaluation of wastewater
management alternatives
- Reviewing Draft and Final Environmental Impact Statements
The Review Committee met at regular intervals throughout the development of
the EIS. In addition, EPA and their consultants met upon request with indi-
vidual members of the Review Committee or with the groups they represented.
The public participation program included one public scoping meeting,
a public workshop conducted in four sessions, three Review Committee meetings,
and a public meeting. The Review Committee was composed of 31 public agencies
and private organizations. A broad range of community interest was included:
state and local government agencies (7), developers (5), homeowners associa-
tions (6), trade associations and business groups (4), Public Service Dis-
tricts (4), and social service and environmental interests (5). Table V-l
lists the members of the Review Committee.
On June 28, 1979, a public scoping meeting was held at the Hilton Head
Elementary School to describe the procedures EPA would use in preparing the
EIS. The meeting included presentations on the purpose and background of the
EIS, the 201 Study, the scope of the EIS and issues to be addressed, the EIS
schedule, and a description of the public participation program. Afterward,
15 citizens and officials made comments.
V-4
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TABLE V-l
EIS REVIEW COMMITTEE
Public Agency
H. Wayne Beam
Charles R. Jeter/Roger Davis
J. Luke Hause
J. Stephen Hopkins
I. Vincent Hager/Perry White
Penn Estabrook/Buddy Thompson
Gordon Craighead
Developers
David Axene/Josh Gold
Benny K. Jones
Robert C. Onorato
William D. Asnip/Bert Newman
P. Ray Easterlin, Jr.
Homeowners Associations
William F. Shopmyer
Elbert Bellows/Emerson Schroeder
Kenneth J. Gutshaw
Charles Haussermann
John D. Hegeman
Josh Gold
S. C. Coastal Council
S. C. Dept. of Health § Environmental Control
S. C. DHEC, Shellfish Division
S. C. Wildlife § Marine Resources Dept.
Beaufort Joint Planning Commission
Low Country COG
Beaufort County Council
Hilton Head Company
Hilton Head Plantation
Palmetto Dunes Resort
Sea Pines Plantation Company
Heritage Properties
Forest Beach Community Assn.
Sea Pines Property Owners Assn.
Assn. of Land Owners of Port Royal Plantation
Palmetto Dunes Property Owners Assn.
Spanish Wells Property Assn.
Shipyard Plantation Property Owners Assn.
Trade Associations and Business Groups
Joe Harden
Ben Banks
Robert H. Christian
Ed Crovo
Private Groups
Barclay Morrison/Willard Haring
Judge Buck Smith
Emory Campbell/Murray Christopher
Thomas C. Barnwell, Jr.
Rev. Ben Williams
Public Service Districts
R. Arnold Ellison, Jr.
T. Kent Langley
William T. Hunter
William J. Parker, Jr.
Home Builders Assn.
Chamber of Commerce
Council of Architects
Hilton Head Hospitality Assn.
Audubon Society
Shellfish Interests
NAACP
Beaufort/Jasper County Comprehensive Health
Program and Hilton Head Fishing Cooperative
Black Community at Large
Sea Pines PSD
Forest Beach PSD
Broad Creek PSD
Hilton Head No. 1 PSD
V-5
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The first Review Committee meeting was held on October 1, 1979 at the
First Presbyterian Church to review the EIS Plan of Study and Background
Task Report. Questions were raised about the adequacy and findings of the
DHEC non-point sampling program to date as well as future sampling efforts.
The purpose of the public participation program was discussed and the Committee
was asked to confirm if all major issues of the EIS had been identified and
incorporated into the work effort.
The format of the first Review Committee meeting and all subsequent ones
consisted of a presentation by the EIS consultants. The Committee was then
divided into three round table discussion groups. At the end of the evening,
a representative from each table summarized the discussion for the benefit of
the other participants and observers.
A meeting was held with the NAACP Board on October 2, 1979 to define the
approach that the EIS consultants should take in documenting the scope of the
local shell fishing industry. Arrangements were made to introduce the con-
sultants to key persons. Other community development problems were discussed
including wastewater management and provision of other public services, land
use, drainage, and water supply.
A public workshop was conducted in four sessions on December 5-6, 1979
at the First Presbyterian Church to address the EIS findings regarding popu-
lation, land use, and the local shellfishing industry. Over 80 persons
attended, including Review Committee members, the general public, and representa-
tives of shellfishing interests. At the conclusion of each workshop, parti-
cipants were asked to complete and return a brief questionnaire. A majority of
those responding indicated that they considered preservation of the island's
environmental quality to be high priority, and over three-quarters indi-
cated that they were willing to pay more for wastewater management to protect
the shellfish industry. WJWJ-TV filmed portions of the workshop and inter-
viewed the EIS consultants in order to produce a 30-minute tape which was sub-
sequently shown on the local PBS channel.
A second meeting was held with the NAACP Board on May 21, 1980 to infor-
mally discuss impacts to the shellfish industry, land use, population, DHEC
sampling results, and alternatives for effluent disposal being developed by
the EIS consultants. The conversations emphasized impacts to the Black Com-
munity and its perception of the EIS issues.
The second Review Committee meeting was held on May 22, 1980 at the
First Presbyterian Church to review the Environmental Inventory Task Report,
wastewater flows, the advantages and disadvantages of spray irrigation for
effluent disposal, the viability of a subaqueous outfall, and the acceptabil-
ity of the continued use of on-lot systems.
The third Review Committee meeting was held on December 8, 1980 to
review the Alternatives Development and Evaluation Task Report. In addition,
the results of DHEC's non-point sampling program and the EPA Barrier Islands
Policy Statement were discussed. As at previous meetings, many island
residents continued to insist that the EIS should control development and
land use allocations on the island. EPA, DHEC, and the EIS consultants
V-6
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reiterated that federal and state governments cannot dictate land use
planning, and control of growth is strictly a local issue.
A third meeting was held with the NAACP Board on December 9, 1980 to
summarize the Alternatives Development and Evaluation Task Report and
solicit comments. Discussion focused mainly on alternatives suitable for
non-PSD areas.
A public meeting was held December 9, 1980 at the Hilton Head Elementary
School to present the findings of the Alternatives Development and Evaluation
Task Report. Approximately 120 citizens attended and 13 made formal state-
ments from the floor. Charles Jeter of DHEC presented his agency's position
on maintenance of SA water quality.
A series of informal meetings were held on August 11, 1981 with those
agencies who would have responsibility for implementing the selected alterna-
tive. Groups involved were the Beaufort County Commission, the County
Attorney, the South Carolina Coastal Council, and PSD representatives.
V-7
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CHAPTER VI
LIST OF PREPARERS
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CHAPTER VI - LIST OF PREPARERS
Project Personnel
U. S. Environmental Protection Agency
Robert B. Howard Chief, EIS Preparation Section
Robert C. Cooper EIS Project Officer
William J. Patton Chief, S.C./Tenn. Facilities Planning Section
Consultants
Gannett Fleming Corddry and Carpenter, Inc.
Thomas M. Rachford Senior Project Manager
D. Randolph Grubbs Project Manager
L. Edward Stom Project Engineer
Henry F. Wilson, Jr. Assistant Project Engineer
Paul Andre DeGeorges Environmental Scientist
John W. Jacobs Environmental Scientist
Claude Terry § Associates, Inc.
Claude E. Terry
Louise B. Franklin
Robert J. Hunter
Thomas C. Mather
Project Executive
Project Manager,
Environmental Planner
Environmental Scientist
Environmental Scientist
VI-1
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APPENDIX A
MEMORANDUM FROM EPA WATER
QUALITY STANDARDS SECTION
A-l
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
DATE; December 5, 1980
SUBJECT:
WLA - Hilton Head, South Carolina
FROM Water Quality Standards Section
Robert Cooper
EIS Branch
SUVMARY;
We have reviewed the WLA's developed by South Carolina DHEC for Hilton Head
South Carolina. Our analysis indicates that for the .45 mgd Sea Pine
discharge, effluent limits of 10 mg/1 8005, 1.5 mg/1 NHHj, and 5 mg/1 DO is
adequate to insure that the 5 mg/1 dissolved oxygen criterion will be met in
Lawton Creek and Lawton Canal. However, according to a Food and Drug
Administration report, any discharge into Lawton Canal would close the canal,
Lawton Creek, and portion of Broad Creek to shellfish harvesting. Since this
would preclude the attainability of a use, we have determined that the WLA
should be 'No Discharge1. If the designated shellfish harvesting use was an
actual use on or after November 28, 1975, then there are no allowances for
eliminating the use. If the use was never attained during that period, then
the use. can only be eliminated if it is environmentally, technologically, or
economically unattainable.
We have no objection to the WLA's for the discharges to Calibogue Sound or
Port Royal Sound, as long as they do not also result in the closure of
shellfish harvesting areas.
Robert F. McGhee
EPA Form 1320-4 (R.v. 3-76)
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APPENDIX B
LETTER FROM SOUTH CAROLINA
WILDLIFE AND MARINE RESOURCES
DEPARTMENT
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RECEIVED ::: 2 3 «»
South Carolina . . , . .,.
James A. I immerman, Jr., Ph.D.
Wildlife & Marine Execut%aDX°nr
Resources Department Law Enforcement
December 8, 1980
Steve Hopkins
P. 0. Box 478
Port Royal, South Carolina 29935
Mr. Robert Cooper
EPA
EIS Project Offices
345 Courtland St., N. E.
Atlanta, Georgia 30308
Dear Bob,
In reviewing the Draft Alternatives Development and Evaluation Talk Report
for the Hilton Head Island Environmental Impact Statement I was distressed
to see how lightly EPA has treated the possible effects of marine disposal
of treated wastewater. As a result, Marine Resources Division would like to
issue strong objections to the alternative evaluations as they are pre-
sented therein. Not only does this report make some questionable assump-
tions about the impact of marine discharges but they have evidently ignored
the fact that an EPA condonation of new marine outfalls will set a precedent
which would eventually result in significant deterioration of the state's
marine resources.
The problem evidentially stems from a failure on the part of EPA to recognize
that treated wastewater may have many serious adverse impacts on the marine
environment in addition to being the source of a possible human health problem.
Sewage outfalls in the marine environment have long existed on the coasts of
the U.S. but until recently, it was thought that their impact was limited
to excessive bacterial contamination of water and shellfish which could result
in the outbreak of diseases in the human population. However, research with-
in the past few years has shown that a sewage discharge into the marine envi-
ronment may affect the system in ways which are subtle but, with time, can
severely limit natural production. Ironically, a treated discharge can in
many instances be more destructive to marine life than the raw sewage. A
few of the deleterious effects associated with treated sewage outfalls are
salinity alterations, changes in the species composition of the phytoplankton
population due to excessive nutrient loads, changes in the BOD due to excess-
ive nutrients, and the toxic effects of the disinfecting agent and ancillary
pollutants.
The effect of a change in salinity due to the presence of sewage treatment
outfall are obvious. While the area in question is populated by many estuar-
ine species which are euryhaline in nature and can adapt to a wide range of
P. O. Box 167 B Dutch Plaza B Building D H Columbia, South Carolina 29202 B Telephone: 803 — 758-6736
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Page 2
salinities, there are also some stenohaline organisms which would not normally
be found in an estuarine system except for the fact that Calibogue Sound
maintains a relatively high salinity. Routine sampling by the RV Carolina
Pride in conjunction with the shrimp management program hasrevealed the exis-
tence of several species of fish and invertebrates in the vicinity of Buck
Island and Bram's Point which are highly intolerant of dilute salinities.
Amoung other organisms, trawl catches included Lane Snapper (Lut.ianus synagris),
Gag Grouper (Mvcteroperca micropelis), Rock Sea Bass (Centropristis philadel-
phica), Soadefish (Chaetodipterus faber) and various species of coral and
lEbWe (4). These animals would be displaced or killed by high volumes fresh
water entering the system. Overall, the degree of species diversity in
Calibogue Sound and adjacent tributaries would be decreased through a reduc-
tion in the salinity.
The species composition of the phytoplankton population in the area around
the outfall would also be altered by the changes in salinity and nutrient
load While a change in the species composition of phytoplankters is not
easily noticed by the layman, or for that matter the scientist, it has a
dramatic affect upon the organisms which rely upon the algae for subsistence.
Often, excessive nutrients will favor population explosions of blue-gree
algae at the expense of green algae and diatoms (6). The blue-greens have a
lower food value to primary consumers such as shellfish and the zooplankters
which support most of the other recreationally and economically valuable
species through the food chain. Therefore, while the total primary production
may increase, the primary producers will be of a type which cannot support
the naturally occurring levels of production.
A shift in the species composition of the algae population from greens and
diatoms to dense blooms of blue-greens though excessive nutrient loading will
also increase the BOD and make the system more susceptible to dissolved
oxygen depletion and the resultant fish kills. (2)
The changes in the ecosystem mentioned above, while serious in themselves,
are overshadowed by a yet more damaging agent. Research conducted over the
past few years has shown that the addition of large quantities of chlorine
to the marine environment is extremely damaging. The best example is the
Chesapeake Bay where the cumulative effect of a large number of treated
sewage outfalls is believed by some to be the primary agent responsible for
the declining fishery resources in what has historically been the largest
seafood producing area in the country. The problem in that area is preceived
to be so serious that the Tidewater Administration of the state of Maryland
may back a bill in that legislature to ban all chlorinated discharges to
surface waters (13). The toxic affects of chlorine has been demonstrated for
a large number of marine organisms, many of which exist in Calibogue Sound
and it's tributaries. A few examples of organisms to which chorine is
toxic are the Rockfish or striped bass (Morone saxatilis) (9), Spotted Sea-
trout (Cynoscion nebulosus) (5), Spot (Leiostomus xanthurus) (11), Atlantic
Siversides (Menidia mendTaT(8). Blue Crabs (Callinectes sapidus)(7) , Mud
Crabs (Panopeus herbstii )(10. 13), Hermit Crabs (Pagurus longi carpus) (10. 13),
Hard Clams (Mercenaria mercenary a) (12) , American Oysters (Crassostrea
virginica)(12, 15, 16, 17) and lower down the food chain, a copepod (Acartia
tonsa)
Several fish kills in Maryland have been attributed to chlorine toxicity (1).
In addition, a 1977 report to the U.S. Congress by the Comptroller General
encouraged EPA to stop unnecessary and harmful levels of domestic sewage
chlori nation (19).
In describing the impact of Alternatives IV-1, IV-2 and IV-3 on surface
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Page 3
water quality it is stated that there will be no significant impact on
Lawton Creek when the existing outfall is removed. This statement is
objectionable since the outfall, even at it's present level, is damaging
the adjacent marine ecosystem as described above. Also, the report indicates
there would be a minor impact associated with an increase in aquatic plants
and algae due to elimination of residual chlorine. A return to normal pri-
mary production must be considered a significant impact.
In Alternative IV-4 it is stated that there will be no impact from main-
taining the present level of nutrient loading and salinity modification.
This statement is objectionable since it assumes that the present outfall
is not damaging to the system. Damage is certainly being done, but without
the opportunity to collect baseline data before the unauthorized outfall
was initiated, it is impossible to quantify.
Discussion of the impacts of Alternative IV-5 note that the effect on
Calibogue Sound will be minor due to it's large assimilative capacity. This
is poor reasoning. Even though the impact may be, at first, unmeasurable
the laws of nature dictate that any pollution or modification of the water
quality must have some effect. In addition, this outfall will set a pre-
cedent for deepwater disposal of treated sewage which, when multiplied
many times through the continued development of coastal areas, will even-
tually result in very definite and serious adverse effects.
The assessment of the impacts of Alternative IV-6 are also objectionable.
It states that the excessive nutrient loading of Lawton Creek will have minor
impact. As explained above, changing the species composition of the primary
producer should be categorized as a significant adverse impact.
Objectionable points in the discussion of Alternative IV-7 are the same as
those mentioned for Alternative IV-5. The checklist of environmental impacts
on the natural environment should make note of a negative impact of Alter-
native IV-7 on surface water quality.
Objectionable points in Alternative IV-8 and IV-9 are the same as for Alter-
native IV-1.
Objectionable points of Alternative IV-10 and IV-11 are the same as for
Alternatives IV-6 and IV-1 respectively.
The checklist of impacts on the natural environment should reflect a nega-
tive impact on the aquatic ecosystem for Alternatives IV-4, IV-5, IV-6, IV-7,
IV-10, and IV-11. In addition, these impacts should be classified as signifi-
cant or major.
EPA assessment of the impacts on the manmade environment with regard to
natural resource use are very much out of line. It is well known that one of
the features of Hilton Head Island that makes it appealing is the fine recrea-
tional opportunities associated with utilization of the marine resources.
However, the Natural Resource Uses impact assessment does not make mention
of the severe adverse effects of Alternatives IV-4, IV-5, IV-6, IV-7, IV-10
and IV-11 on recreational opportunities. As noted above, an outfall and the
precedent it sets can severely limit the production of important recreation-
ally and commercially exploited species, such as crabs, oysters and finfish.
For these six alternatives which involve a marine outfall, the significant
positive impact bought about by conservation of the ground water resources
will be offset by significant negative impacts on the marine life. A more
sensible approach would be to relay the excess effluent from the Sea Pines,
Forest Beach PDS to areas which can not meet the irrigation requirements of
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Page 4
their golf courses with the available treated effluent. In this way, the
positive impacts will be increased while eliminating the negative impact of
marine disposal.
(1) Berlitz, A. (1980). Villian in Disguise. Atlantic
States Marine Fisheries Commission Meeting, October 1980,
Hershey, PA.
(2) Garside, C. ejt aQ_, (1976). Evaluation of sewage
derived nutrients and their influence on Hudson Estuary.
ESTUARINE AND COASTAL AMRINE SCIENCE 4:281-289.
(3) Heinle, D. R. and M. S. Beaven (1977). Effects of
Chlorine on the Copepod Acartia tonsa. CHESAPEAKE SCIENCE
18 (1):140.
(4) Jenkins, J (1980). Crustacean Management Section, Office
of Conservation Management and Marketing, Marine Resources
Division. Personl Communication.
(5) Johnson, A. G. et al_. (1977). Chlorine-Induced Mortality
of Eggs and Larvae of Spotted Seatrout (Cynoscion nebulosus).
TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY 106 (5):466-
469.
(6) Kosaric, N and H. T. Nguyen (1974). Growth of Spirulina
maxima in Effluents from Waste Treatment Plants, BIOTECHNOLOGY
AND BIOENGINEERING 16:881-896.
(7) Laird, C. E. and M. H. Roberts (1979). Effects of Chlorinated
Seawater on the Blue Crab, Callinectes sapidus. WATER
CHLORINATION, ENVIRONMENTAL IMPACT AND HEALTH EFFECTS, Vol. 3,
R. L. Jolly, Ed. (Ann Arbormmi: Ann Arbor Science Publishers,
Inc., pp. 569-579.
(8) Meldrim, J. M. and J. A. Fava, Jr. (1977). Behavioral
Avoidance Responses of Estuarine Fishes to Chlorine.
CHESAPEAKE SCIENCE 18 (1): 154-157.
(9) Middaugh, D. P. et al. (1977). Responses of Early Life
History Stages of tfie~ Striped Bass, Morone saxatilis to
Chlorination. CHESAPEAKE SCIENCE 18 (D-141-153.
(10) Roberts, M. H. (1977). Effects of Chlorinated Seawater on
Decapod Crustaceans. WATER CHLORINATION, ENVIRONMENTAL IMPACT
AND HEALTH EFFECTS, Volume 2, R. L. Jolly Ed. (Ann Arbor, MI:
Ann Arbor Science Publishers, Inc., pp. 329-339.
(11) Roberts, M. H. (1979). Survival of Juvenile Spot (Leiostomus
xanthurus) Exposed of Bromochlorinated and Chlorinated
Sewage in Estuarine Waters. MARINE ENVIRONMENTAL RESEARCH
3:63-80.
(12) Roberts, M. H. et al_. (1975). Acute Toxicity of Chlorine to
Selected Estuarine Species. JOURNAL OF THE FISHERIES RESEARCH
BOARD OF CANADA 32 (12): 2525-2528.
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Page 5
(13) Roberts, M. H. et_ a\_. (1979). Effects of Chlorinated Sea-
water on Decapod Crustaceans and Mulinia Larvae. U. S.
Evironmental Protection Agency Report EPA-600/3-79-031,
Environmental Research Laboratory, Gulf Breeze, FL.
(14) Roop, R. (1980). Technical Manager of Environmental Products,
Fisher Porter, Inc., War-minister, PA, Personal Communication.
(15) Scott, G. I. and Middaugh, D. P. (1977). Seasonal Chronic
Toxicity of Chlorination to the American Oyster, Crassostrea
virginica. WATER CHLORINATION, ENVIRONMENTAL IMPACT AND HEALTH
EFFECTS, Volume 2, R. L. Jolly, Ed. (Ann Arbor MI: Ann Arbor
Science Publishers, Inc., pp. 311-328.
(16) Scott, G. I. et _al_. (1979). Physiological Effects of Chlorine
Produced Oxidants and Subsequent Uptake of Chlorination
By-Products in the American Oyster, Crassostrea virqinica.
Environmental Protection Agency Report, Bears Bluff Labora-
tory, Wadmalaw Island, SC.
(17) Scott, G. I. And W. B. Vernberg (1979). Seasonal Effects
of Chlorine Produced Oxidants on the Growth, Survival and
Physiology of the American Oyster, Crassostrea virqinica.
MARINE POLLUTION: FUNCTIONAL RESPONSES. Academic Press, Inc.
(18) Speir, H. (1980). State of Maryland Depaartment of Natural
Resources, Tidewater Administration. Personal Communication.
(19) United States Comptroller General (1977). Report to the
Congress, Unnesessary and Harmful Levels of Domestic Sewage
Chlorination Should Be Stopped. Government Accounting
Office Report CED-77-108.
Sincerely,
JSH/kh
Steve Hopkins
Regional Biologist
OCMM
cc: Charles M. Bearden, Director,
Office of Conservation, Management and Marketing
Marine Resources Division
Rob Dunlap, Section Leader,
Environmental Control, OCMM, Marine Resources Division
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APPENDIX C
LETTER FROM SOUTH CAROLINA
DEPARTMENT OF HEALTH AND
ENVIRONMENTAL CONTROL
C-l
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RECEIVED SEP_- 2 1980
William M. Wilson, Chairman
J. Lorin Mason, Jr., M.D., Vice-Chairman
I. DeQuincey Newman, Secretary
Leonard W. Douglas, M.D.
George G. Graham, D.D.S.
Michael W. Mims
Barbara P. Nuessle
eoth and
Environmental
Roberts. Jackson, M.D.
2600 Bull Street
August 29, 1980 Columbia, S. C. 29201
Mr. D. Randolph Grubbs
Gannett, Fleming, Cordory and Carpenter
Number 11, Koger Executive Center
Suite 250
Norfolk, Virginia 23502
Dear Randy:
In response to your request, we have analyzed the effects of discharges
from Hilton Head Island as proposed in your letter of August 12, 1980. Based
on our analysis, proposed discharges would be subject to effluent limits as
follows:
1. Sea Pines PSD discharge to Lawton Canal at existing location. The system
is so complex that present modeling techniques do not appear to apply.
Based on the nature of the system, we believe advanced treatment to the
following levels are applicable:
Discharge Flow BODs NH3 Tot. Colif. TSS P.O.
0.70 MGD 10 mg/1 1.5 mg/1 70/100 ml 15 mg/1 5.0 mg/1
1.0 MGD 10 mg/1 1.5 mg/1 70/100 ml 15 mg/1 5.0 mg/1
2.0 MGD 10 mg/1 1.5 mg/1 70/100 ml 15 mg/1 5.0 mg/1
3.0 MGD 10 mg/1 1.5 mg/1 70/100 ml 15 mg/1 5.0 mg/1
2. Sea Pines PSD discharge to Calibogue Sound:
Discharge Flow BODs NH3 Tot. Colif. UOD TSS
3.0 MGD 30 mg/1 — 70/100 ml -— 30 mg/1
Secondary treatment would be adequate. Additional assimilative capacity is
available. The limitation on TSS is what is required by secondary treatment.
At high levels of BOD removal, TSS should be well within 30 mg/1.
3. Hilton Head PSD No. 1 discharge to Port Royal Sound:
Discharge Flow BODs NHs Tot. Colif. UOD TSS
0.2 MGD 30 mg/1 — - 70/100 ml — 30 mg/1
Secondary treatment would be adequate. Additional assimilative capacity is
available.
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Letter to Mr. D. Randolph Grubbs
Page 2
August 29, 1980
For any discharge to Calibogue Sound, a maximum of 9,000 Ibs. UOD/day
is allowable to reach 4 shown on the enclosed map. This allowable load was
determined as part of the Low Country 208 planning program. The discharge point
would have to be located in a deep part of the sound to ensure maximum mixing
and dispersion. A discharge of secondary effluent at 3.0 MGD would produce a
load of 3,378 Ibs/day of UOD.
For any discharge to the lower portion of Port Royal Sound, a maximum
load of 28,000 Ibs/day of UOD is allowable to reach 9 shown on the enclosed map.
This allowable load was also determined as part of the Low Country 208 planning
program. Any discharge here would also have to be located in a deep part of
the sound to ensure maximum mixing and dispersion of the effluent.
"Buffer Zones" for the proposed discharges are very difficult to define.
The FDA guidelines use terminology of "Safety Area" for what we have called
buffer zone. There should be reasonable assurance when treatment facility mal-
functions occur resulting in a non disinfected wastes discharge that State Health
Authorities would be notified and the affected area closed to shellfish harvesting
within a 24 hour period. In past application of the buffer zone policy, the
affected area has been assumed to be that area to which the pollutant would
disperse within 2 tidal cycles (approximately 24 hours). It is not possible
to reduce the buffer zone by having a disinfected discharge enter a retention
pond with a retention time of at least 24 hours. This will merely allow DHEC
to have more response time to monitor the affected area and determine bacteria
levels in surrounding areas. During normal operation certain areas outside the
buffer zone could be conditionally approved for shellfish harvesting. This may
be a consideration for a discharge to Lawton Canal. However, it should not be
a concern for discharges to Calibogue Sound or Port Royal Sound. We cannot
create other hypothetical situations to analyze their effect on buffer zone
boundaries. If you wish to propose specific alternatives, we would be willing
to respond to them.
The buffer zone for the present Sea Pines PSD discharge to Lawton Canal
includes all of Lawton Creek to its confluence with Broad Creek. It also includes
1,000 feet of the east bank of Broad Creek North and South of Lawton Creek.
According to a Food and Drug Administration report (December 1978), if the dis-
charge was increased to 4 MGD, the buffer zone would be extended to just above
Harbor Town Marina to the South and to the Northern tip of Buck Island in the
Norther direction. Conditionally approved areas will be moved to include all
of Palmetto Bay and all of Harbor Town Marina.
If the proposal is to discharge treated wastewater to Lawton Canal,
the use of backup systems, holding basins, and emergency alarm systems could
reduce the size of the conditionally approved area.
If I can be of further assistance, please do not hesitate to call.
CRJ:CES/skb
cc: Robert Cooper, EPA
Roger Davis, SCDHEC
Luke Hause, SCDHEC
Sincerely/
/ / '/
tharies R.Jeter, P.E., Chief
Bureau of Wastewater § Stream
Quality Control
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From: Areawide Water Quality
Management Plan. Low Country
Council of Governments. P. 0.
Box 98, Yemassee, S. C. 29945,
pp. 3-2-17 and 3-2-19.
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APPENDIX D
LETTER FROM OFFICE OF THE
ATTORNEY GENERAL FOR THE
STATE OF SOUTH CAROLINA
D-l
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RECEIVED
LADSON F. HOWELL
A. PARKER BARNES. JR.
H. MICHAEL BOWERS
JAMES S. GIBSON. JR.
HOWELL. BARNES. BOWERS AND GIBSON. P.A.
ATTORNEYS AT LAW
June 18, 1981
1214 KINO STREET
POST OFFICE BOX 4O
BEAUFORT. SOUTH CAROLINA 299O2
8O3 - 5S4-3433
STEPHEN P. HUGHES
Mr. Robert Cooper
Environmental Protection Agency
Environmental Impact Statement Branch
345 Courtland Street
Atlanta, GA 30365
RE: Sea Pines Public Service District—Condemnation Authority
Dear Mr. Cooper:
By letter of April 23, 1981, I requested a written opinion of the Attorney
General in answer to the following questions regarding the extent to which the
power of eminent domain may be exercised by the Sea Pines Public Service
District and/or the County of Beaufort:
1. As a means of disposing of waste water, the Sea Pines Public Service
District proposes to irrigate private property with such waste water. Is the
condemnation authority of the Sea Pines Public Service District sufficient to
allow it to take private property outside its district boundaries for such
purposes?
2. Is the condemnation authority of the County of Beaufort sufficient to
allow it to take private property for such purposes in the name of the public
service district?
The responsive opinion of the Attorney General is enclosed for your consideration.
It appears that the Sea Pines Public Service District, for the reasons enumerated
in the opinion, is without condemnation authority sufficient to allow it to take
private property outside its district boundaries. However, it is the further
opinion of the Attorney General that the condemnation authority of the County of
Beaufort may be used to assist the Sea Pines Public Service District in the
control of waste water.
Should you have any questions regarding the content of this correspondence,
please do not hesitate to contact me.
Yours very t
xc: T. H. Rachford
Central File: Hilton Head EIS
Job No. 8021.00
ydson F. Howell
Beaufort County Attorney
LFri: cmb
Enclosure
cc: M. O'Neill and A. Horner
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e jitatc of J^aiitb (EaroL.a
(Office of the J\tturney G5iMterai
REM3ERT C DENNIS BUILDING
DANIEL R. MCLEOO POST OFF.CE BOX ,,549
ATTORNEY GENERAL COLUM8.A.SC. 29211
TELEPHONE 803-758-2072
June 10, 1981
Stephen P. Hughes, Esquire
Assistant County Attorney
Beaufort County
Post Office Box 40
Beaufort, South Carolina 29902
Re: Sea Pines Public Service District - Condemnation
Authority
Dear Mr. Hughes:
You have asked whether or not the Sea Pines Public
Service District may use its power of eminent domain to condemn
private property outside its boundaries for the purpose of
disposing of x-?aste water. You have also inquired whether, if
the answer to the first question is negative, the County of
Beaufort may condemn the property for such purposes in the name
of the Public Service District.
The Sea Pines Public Service District was created by
Act 1158, Acts and Joint Resolutions (1964) to provide certain
services deemed necessary by the General Assembly to protect the
health of the rapidly increasing population of Hilton Head Island.
Among its enumerated powers are building, constructing, and operating
such waterworks, sewage facilities, and medical clinics found
necessary by the governing Commission. In order to accomplish
the objectives of the District the General Assembly also granted
the governing commission the power of eminent domain. There is
no question that, upon-approval of the appropriate State and
Federal Environmental Protection Agencies, the District could
condemn private property within the boundaries of the District
for disposal of waste water in the manner described in your letter.
However, there is no statutory grant of jurisdiction or authority
to the Commission for any purpose whatsoever beyond the boundaries
of the District.
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Stephen P. Hughes, Esquire
Page Two
June 10, 1981
The General Assembly expressly granted municipalities
soir.e latitude in condemning property outside their corporate
boundaries. Section 28-9-110, Code. 3y another statute, the
Legislature granted private water companies all of the rights and powers
possessed by municipalities relative to water service. Section
58-7-30, Code. It logically follows that, if the Legislature
had intended to grant to the Commission the power of eminent
domain over property outside the boundaries of the District,
it would have done so by express provision. Because the District
is a creature of statute, it possesses only that authority expressly
granted in the statute or that which is incidentally necessary for
the exercising of expressly granted authority. Richland County
Department of Public Welfare v. Mickens, 246" S.C~113, 142 S.E.2d
737(1965).Although condemning property outside the District
boundaries might enhance or improve the operation of the District,
it is not incidentally necessary for the operation of the District.
It is, therefore, the opinion of this office that the Sea Pines
Public Service District may not exercise the power of eminent domain
outside its statutorily defined boundaries/
As to your second question, the only relevant limitation
upon the exercise of eminent domain by Beaufort County is that the
taking must be for a County purpose. Section 4-9-30, Code. It
is evident that the harm to the environment from pollution
of the coastal waters and marshes presents a danger to inland
residents of Beaufort County to almost as great a degree as those
living within the Public Service District itself. The General
Assembly obviously recognized this fact when it created the
District to control sewage disposal and the distribution of drinking
water, making a finding, in part, that:
"The development of recreational facilities
and multi-unit accomodations, in the nature
of inns, clubs, and ^apartment buildings,
will make construction of a sewage .disposal
system a health necessity." Act 1158, Section
2, Acts and Joint Resolutions (1964).
Having determined that the control of sewage disposal
in the rapidly developing coastal zone of Beaufort County is a
proper county function, it is the opinion of this office that
Beaufort County may use its power of eminent domain to assist the
Sea Pines Public Service District in the control of waste water.
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Stephen P. Hughes, Esquire
Page Three
June 10, 1981
I trust this has sufficiently answered your questions
If not, please feel free to contact us'at your convenience.
Sincerely,
0. Koon, Jr
Attorney General
COKjr-.prl
REVIEWED ^AND APPROVED BY:
Victor S. Evans
Deputy Attorney General
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