[Added by Ord. No. 99-07]
A.
There are areas within Fredon Township which are underlain by carbonate
bedrock such as limestone and dolomite. The solution of the bedrock
causes surface depressions, open drainage passages, and the development
of irregular, subsurface rock topography known as karst. These conditions
make such areas unstable and susceptible to subsidence and surface
collapse. As a result, the alteration of drainage patterns in these
areas by the placement of impervious coverage, grade changes, or increased
loads from site improvements can lead to land subsidence and sinkholes.
B.
Fractures or solution openings and fissures in the limestone rock
may lead to public or private water supplies, making those sources
especially susceptible to groundwater contamination. Contamination
of water sources can occur from solid and liquid wastes, contaminated
surface water, septic tank effluent, or other hazardous substances
moving through fractures or solution openings and fissures within
the rock.
C.
Carbonate aquifers are an important source of groundwater in Fredon
Township. The Township relies on a clean supply of subsurface water
to foster and promote human health, welfare and economic and social
development. Therefore, the purposes of enacting this chapter are
to protect, preserve and enhance a sensitive and valuable potable
groundwater resource area and to reduce the frequency of structural
damage to public and private improvements by sinkhole collapse or
subsidence in areas of limestone geology, thus protecting the public
health, safety and welfare and insuring orderly development within
the Township.
The provisions of this chapter shall be applicable to development
activities in the Carbonate Area District requiring preliminary major
subdivision approval or preliminary site plan approval from the Fredon
Township Land Use Board.
The Carbonate Area District is hereby created and shall be any
area identified as such upon the Fredon Township "Carbonate Area District"
map.[1] The district shall be constituted as secondary, or as
an "overlay," to the zoning districts heretofore established by the
Zoning Map and may encompass all or portions of more than one existing
zoning district. Regulation of the CAD shall be in addition to those
requirements governing the existing zoning district. The Carbonate
Area District shall contain two areas which shall be known as the
Carbonate Rock District and the Carbonate Drainage Area.
A.
Carbonate Rock District (CRD). The Carbonate Rock District is composed
of those areas of the municipality underlain by limestone or carbonate
rocks. The geologic mapping utilized to prepare the CRD overlay boundary
is derived from New Jersey Geologic Survey and United States Geological
Survey maps. These maps are interpretations developed from available
field observations and subsurface data. Additional unmapped areas
of limestone rocks may exist in Fredon Township. The provisions of
this chapter may therefore be applied to any development which, in
the opinion of Fredon Township, is located in an area underlain by
limestone. The CRD map shall be updated as information is developed
through the application of this chapter.
B.
Carbonate Drainage Area (CDA). The Carbonate Drainage Area shall
consist of all lands which drain surface water into the Carbonate
Rock District. Changes in the quantity, quality and rate of discharge
of surface water runoff from lands upslope of the Carbonate Rock District
can adversely affect the CRD. Therefore, development activities in
the CDA which may alter the surface drainage patterns or affect the
water quality or increase runoff into the CRD shall be subject to
the requirements of this chapter.
[1]
Editor's Note: Said map is included at the end of this chapter.
A.
All applicants filing for preliminary major subdivision approval or preliminary site plan approval from the Fredon Township Land Use Board shall undertake a geotechnical investigation program. Projects located in the Carbonate Drainage Area shall complete the Phase I requirements. Projects located in the Carbonate Rock District shall first complete the Phase I requirements. The submission of the Phase II requirements shall be based on the recommendation of the municipal geotechnical consultant (GTC) to the Land Use Board pursuant to § 45-53.
B.
The geotechnical investigation program shall be prepared by a professional
engineer or geologist with experience in karst terrain. The municipality's
geotechnical consultant (GTC) shall be similarly qualified to review
all projects submitted.
C.
The geotechnical investigation program shall identify the geologic
nature of the materials underlying the site.
D.
The geologic investigation report shall evaluate site information
gathered during the geotechnical investigation, and provide recommendations
for the planning, engineering design, and construction techniques
to be utilized. All design recommendations shall minimize, to the
greatest extent practical, impacts upon water quality and structural
hazards associated with limestone formations.
E.
In that the results of the geologic investigation are essential for
the planning, engineering design and construction techniques to be
utilized on the project, the geologic investigation program shall
be completed and the geologic investigation report filed with the
formal application for preliminary major subdivision or preliminary
site plan approval. Prior to the submission of an application for
preliminary major subdivision or a preliminary site plan, the applicant
may, and is encouraged, to consult or meet informally with the municipal
geotechnical consultant or the Land Use Board as deemed necessary
to receive guidance on their investigation.
For all properties located in the CAD, a comprehensive geologic
investigation program shall be conducted by the applicant. The purpose
of this program is to provide the Land Use Board with sufficient data
to define the nature of all existing geologic conditions that may
affect construction and land use activities on the site. Specifically,
the investigations shall yield information which shall demonstrate
that the proposed development will identify any existing geologic
conditions for which appropriate site design and/or engineering solutions
may be necessary to minimize any adverse environmental impacts caused
by the project. The geotechnical investigation program consists of
the following:
A.
The applicant shall complete the Phase I requirements. Upon completion,
the applicant shall have the option to submit the information to the
Land Use Board to obtain an informal review and guidance prior to
proceeding with Phase II.
B.
The applicant shall complete the Phase II requirements. Upon completion,
the applicant shall have the option to submit the information to the
Land Use Board to obtain an informal review and guidance prior to
proceeding with the on-site geotechnical investigation.
C.
Applicant undertakes on-site geotechnical investigation program in accordance with § 45-53 with observation by municipal GTC.
D.
Submission of a geotechnical investigation report by the applicant.
E.
Municipal GTC review of the geotechnical investigation report and
final recommendation to the Land Use Board.
A.
U.S. Geologic Survey 7 1/2 minute topographic quadrangle maps
with parcel identified.
B.
U.S.D.A. Soil Conservation Service soil survey map indicating soils
present on parcel.
C.
Information from any special reports completed by the N.J. State
Geological Survey, U.S. Geologic Survey, or the N.J. Department of
Environmental Protection.
D.
Site plan map at a scale of one inch equals 1,000 feet identifying
proposed development site and boundaries of site that are within the
CRA and/or CDA as designated on the municipal CAD map.
E.
Aerial photograph print of the proposed site and surrounding area
at a minimum scale of one inch equals 1,000 feet obtained during periods
of minimum foliage.
F.
Location of all known water production wells and well log information
with 1/2 mile of the project.
G.
A project sketch plat at a minimum scale of one inch equals 200 feet
with existing surface water bodies, location of any existing water
production wells, faults, outcrops, springs, sinkholes, disappearing
streams, and surface water flows.
H.
Written narrative describing proposed activity.
I.
If the project includes the storage or manufacturing of toxic or
hazardous materials, provide an explanation of the activity.
J.
Other published geologic information which the applicant deems pertinent,
such as information from other geologic investigation programs which
are on file with the municipal Clerk or other agencies.
A.
General requirements.
(1)
Test borings and test pits are to be used as the primary means of
identifying potential geologic hazards. Percussion probes and other
geophysical techniques (e.g., seismic refraction and reflection, ground-penetrating
radar, magnetic gravity and conductivity) can be used to provide data
between test borings and pits.
(2)
Proposed exploration techniques which are not outlined in this chapter
may be submitted to the GTC for review and possible inclusion in the
approved investigation program. Alterations to the planned program
can be made during the progress of the field investigation upon request
to the GTC if so required by the nature of the encountered subsurface
conditions.
(3)
The intention of the site investigation program is to define the
nature and limits of possible design, construction and operating concerns
that could result from the existence of carbonate soil and/or rock
formations underlying the proposed development site.
(4)
Name and address of New Jersey licensed engineer, New Jersey licensed
well driller, and geologic consultant to be used.
B.
Direct testing procedures.
(1)
Provide number of proposed test borings. The minimum number of borings
required is shown in the following table; however, the municipal geotechnical
consultant may require additional tests as site conditions warrant.
|
Type of Development
|
Foundations
|
Infrastructure
|
Stormwater Management
| |
|---|---|---|---|---|
|
Residential
| ||||
|
1 to 10 dwellings
|
1 per dwelling
|
1 per 1,000 feet roadway
|
2 per basin
| |
|
11 to 50
|
0.15 per dwelling
|
0.75 per 1,000 feet roadway
|
2 per basin
| |
|
>50 dwellings
|
0.1 per dwelling
|
0.5 per 1,000 feet roadway
|
2 per basin
| |
|
Nonresidential
| ||||
|
0 to 5,000 square feet building area
|
0.4 per 1,000 square feet building area
|
0.33 per 1,000 S.Y. impervious
|
2 per basin
| |
|
5,001 to 10,000 square feet building area
|
0.3 per 1,000 square feet building area
|
0.3 per 1,000 S.Y. impervious
|
2 per basin
| |
|
>10,000 square feet building area
|
0.2 per 1,000 square feet building area
|
0.2 per 1,000 S.Y. impervious
|
2 per basin
|
|
*
|
Note: Additional investigation may be required
based upon actual field conditions encountered.
|
(2)
Provide anticipated depth of borings. If rock is encountered within
40 feet of ground surface, a minimum of 10 feet rock is to be cored.
Rock cores shall be a minimum of two inches in diameter to be obtained
by double tube, split barrel coring device or equivalent.
(3)
Describe boring techniques to be used. Unless written approval is
obtained, all test borings will be drilled using rotary wash/without
use of drilling muds. Water losses in borings are to be monitored
as to depth and quantities. Air loss, drilling speed and rod drops
must also be monitored.
(4)
Describe proposed borehole grouting techniques. Grouting shall be
in accordance with N.J.A.C. 7:9-9.1 et seq.
(5)
Provide description of proposed monitoring wells.
(6)
Describe anticipated soil and rock sampling procedures. Sampling
shall be in accordance with ASTM D420, D1586, D1587 and D2113.
(7)
Borings and test pits shall be logged in accordance with the Unified
Soil Classification System and in relation to the geologic origin
of the constituents of the encountered materials, i.e., light yellow
brown silty clay (CH), with occasional angular dolomite fragments,
moderately stiff, residual soils, some stained paleo jointing.
(8)
Provide number and depth of proposed test pits. The minimum bottom
area of pits shall be 10 square feet and shall encounter rock surface
over 50% of the pit area.
(9)
Describe proposed method of test pit backfill. Test pit backfill
shall be composed of excavated material placed in layers and compacted
to preexcavation density, unless authorized otherwise by GTC.
(10)
Provide proposed number and types of piezometers and/or lysimeters
to be used. They shall be installed and monitored in sufficient locations
to identify depth to seasonable high water table and the rate and
direction of groundwater flow.
(11)
Provide descriptions of any other proposed methods for measuring
groundwater levels and rate and direction of flow.
(12)
Provide description of methods for the geochemical testing of
the properties of soils, rock and water.
C.
Indirect testing procedures.
(1)
Provide the proposed number, anticipated depths, and measuring techniques
of proposed percussion probes.
(2)
Describe the proposed number of seismic refraction and reflection
tests and equipment to be used.
(3)
Describe the proposed number of ground-penetrating radar tests and
equipment to be used.
(4)
Describe the proposed number of magnetic, gravity or conductivity
tests and equipment to be used.
(5)
Describe geologic reconnaissance factors to be examined, i.e. vegetative
changes, observable seeps or groundwater discharge, circular depressions,
swales.
(6)
Describe any other geologic reconnaissance field investigation techniques
proposed.
D.
Maps, drawings and other documentation.
(1)
Provide the location of the site on 1:24,000 scale U.S.G.S. topographic
map and general site plan showing proposed locations of all field
testing procedures in relation to the planned development at a minimum
scale of one inch equals 100 feet.
(2)
Provide timetable of proposed field investigation, laboratory testing,
test data receipt and final report to the Land Use Board.
(3)
Describe proposed technical inspection procedures during investigation.
Continuous technical supervision of field investigation is strongly
recommended.
(4)
Describe any special factors or conditions the applicant wishes to
bring to the attention of the GTC.
A.
On-site investigations and tests undertaken pursuant to this chapter shall not begin until the applicant has submitted the appropriate fees as required in Article VIII and has provided proper notice to the municipality. The applicant shall be responsible for providing, at least 15 days prior to commencement of any testing procedures, written notice of same to the municipal Clerk, which notice shall be transmitted by certified mail, returned receipt requested or served personally. All site investigations shall be properly closed in accordance with N.J.A.C. 7:9-9.1 et seq.
B.
The proposed development site shall be subject to inspection by the
GTC or designated municipal inspectors at any time. All testing data
and results shall be made available to municipal officials and inspectors
on demand.
C.
All samples taken shall be properly preserved and shall be available
for examination by the municipality upon request until final action
is taken by the Land Use Board on the application.
A.
At the completion of the field investigation, a formal site investigation
report shall be submitted and include any of the following required
information gathered during the testing protocol:
(1)
Logs of all borings, test pits, and probes including evidence of
cavities, loss of drilling fluid circulation during drilling, voids
encountered and similar cavities.
(2)
Type of drilling or excavation technique employed.
(3)
Drawings of monitoring or observation wells as installed with results
of monitoring.
(4)
Time and dates of explorations and tests.
(5)
Reports of chemical analyses of on-site surface and groundwater and
the potential for reaction with the underlying rock with an assessment
of the likelihood of formation of solution cavities.
(6)
Names of the individuals conducting the tests if other than the New
Jersey licensed engineer, New Jersey licensed well driller, or geologic
consultant provided in the Phase II requirements.
(7)
Analytical methods used on soils, water samples, and rock samples.
(8)
A one inch equals 100 feet scale topographic map of the site (at
a contour interval of two feet) locating all test pits, borings, wells,
seismic or electromagnetic conductivity or other geophysical surveys
in relation to the proposed development.
(9)
Analysis of the groundwater, including any potentiometric maps constructed
from site data or aquifer tests with rate and direction of flow.
(10)
A geologic interpretation of the observed subsurface conditions,
including soil and rock type, jointing (size and spacing), faulting,
voids, fracturing, grain size, and the likelihood of sinkhole formation,
especially in projects where water from storm sewers, roof drains,
septic systems etc. is being discharged into the ground.
B.
The report shall also define the extent of geotechnical findings
at the site in relation to the planned development or land use. The
engineering solutions proposed to minimize environmental and structural
impacts for the useful life of the project as well as during construction
must be clearly detailed together with the bases for the conclusions
reached. The report shall, as a minimum, address the following:
(1)
The probable effects of the proposed development upon Township water
resources and the likelihood of future sinkhole formation.
(2)
The appropriateness of the site for the proposed development and
the appropriateness of the location and design of proposed roadways,
buildings, and facilities for stormwater management, water supply
and sewage disposal.
(3)
The adequacy of support for buildings, roadways, utility lines. Foundations
should be reinforced to span a minimum of 10 feet of soft soils or
voids.
(4)
Stormwater and sanitary sewer lines shall be designed and constructed
with watertight joints which have been tested to ensure their integrity.
(5)
Pipe materials, joints, construction methods and materials, and infiltration
or exfiltration testing shall be subject to the approval of the municipal
engineer.
(6)
Pressurized utility lines shall provide for automatic shutoff when
sudden pressure loss is detected.
(7)
Site grading and blasting shall be minimized.
(8)
General methodology for management of sinkholes or solution cavities,
depressions, or other questionable areas which have been discovered
during the investigation or which could be discovered during construction.
(9)
Provisions for inspection and monitoring during construction and
any long term inspection or monitoring which may be recommended. It
is strongly recommended that the developer employ the services of
an expert in construction in karst terrain to be on site during all
construction activities requiring excavation.
The GTC's review of the geotechnical investigation report
for proposed development in the CRD shall consider the data, formal
reports, maps, drawings and related submission materials and shall
advise the Land Use Board whether or not the applicant has provided
the municipality with:
A.
Sufficient design, construction and operational information to insure
that the proposed development of the tract will not adversely impact
on the health, safety and welfare of the community.
B.
Proof that the proposed method of development of the tract will minimize
any adverse effects on the quality of surface or subsurface water,
and will not alter the character of surface and/or subsurface water
flow in a manner detrimental to known on-site or off-site conditions.
C.
Specific details insuring that design concepts and construction and
operational procedures intended to protect surface and subsurface
waters will be properly implemented.
D.
Specific details on inspection procedures to be followed during construction
and after project completion.
E.
The following note shall be provided on the final subdivision plat
or final site plan for any project located within the CRD: "This site
is underlain by limestone formations which are susceptible to sinkholes
and subsidence. The occurrence of sinkholes and/or subsidence is not
predictable and therefore the municipality, its employees, the municipal
engineer, and the municipal geotechnical consultant assume no liability
for any damages which may occur on private property as a result of
the formation of sinkholes or subsidence."
In certain situations, a specific geologic hazard may not be
identified while the geologic investigation program is underway and
may be discovered during or after construction. In such cases, the
applicant shall:
A.
Report the occurrence of the hazard to the municipal Clerk within
24 hours of discovery.
B.
Halt construction activities which would impact the geologic hazard.
C.
Prepare a report on the geologic hazard which analyzes the impact
of the hazard and details a remediation plan for review and approval
by the municipal geotechnical consultant.
D.
After obtaining approval from the municipality, perform necessary
remediation of the hazard to prevent or minimize damage to buildings,
structures, utilities, driveways, parking areas, roadways, and other
site improvements, and to minimize pollution of the groundwater.
E.
Repair any damage to improvements and restore ground cover and landscaping.
F.
In those cases where the hazard cannot be repaired without adversely
affecting the site plan or subdivision, the applicant shall file an
amended application for site plan or subdivision approval in compliance
with the provisions of this chapter.
A.
Compliance with this chapter is required prior to the granting of preliminary major subdivision or preliminary site plan approval unless waivers have been granted by the Land Use Board pursuant to § 45-60. The enforcement officials for any application requiring approval under this chapter are the municipal engineer and/or the municipal GTC.
B.
Failure to comply with any of the conditions in this chapter may
result in the issuance of a stop-work order, revocation of building
permits, or denial of certificates of occupancy. Remedial and corrective
measures may be mandated if the appropriate construction and site
planning techniques, as outlined in the applicant's approved
geotechnical report, are not followed and result in actions which
adversely impact karst features.
A.
Application fee. For any project in the CAD requiring a submission,
the applicant shall pay an application fee in the amount of $500.
C.
Inspection fee.
(1)
It is recognized that the Municipal Land Use Law, particularly N.J.S.A.
40:55D-53(h), provides a limitation on engineering inspection fees
which shall, in all cases, be reasonable and shall, except for extraordinary
circumstances, be limited to the greater of $500 or 5% of the cost
of improvements, which cost of improvements shall be determined pursuant
to N.J.S.A. 40:55D-53.4.
(2)
It is also recognized that when the testing methodology provided
for herein has been employed and determines the existence of critical
geological formations underlying the site of the proposed development,
extraordinary and exceptional construction methods may be required
to be employed by the developer during site improvements, which work
is required to be witnessed by the municipal engineer or his representative.
(3)
The construction of improvements in developments underlain by critical
geological formations is herewith deemed to constitute an extraordinary
circumstance, thereby rendering inapplicable the engineering inspection
fee limitations otherwise provided by N.J.S.A. 40:55D-53(h) and enabling
the charging of inspection fees in excess thereof which, in all cases,
shall be reasonable and shall otherwise comply with the requirements
of N.J.S.A. 40:55D-53.
A.
In limestone areas, the alteration and development of land may be
hazardous with respect to the foundation safety of structures, the
creation of unstable land as a result of changes in drainage and grading,
and the contamination of ground and surface waters.
B.
The exact occurrence of sinkholes and/or subsidence is not always
predictable; therefore, the administration of these regulations shall
create no liability on behalf of the municipality, the municipal engineer,
the municipal geotechnical consultant, municipal employees, or municipal
agencies as to damages which may be associated with the formation
of sinkholes or subsidence. Compliance with these regulations represents
no warranty, finding, guarantee, or assurance that a sinkhole and/or
subsidence will not occur on an approved property. The municipality,
its agencies, consultants, and employees assume no liability for any
financial or other damages which may result from sinkhole activity.
C.
It is also noted that sinkholes and ground subsidence may occur in
areas outside the CRD and/or in areas of carbonate geology presently
not identified as such. The applicant and/or property owner should
always make independent investigations of these matters prior to using
this land for construction of a building or structure or any activity
which alters the soil and bedrock materials.
