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[Added 8-2-2004 by Ord. No. 247]
The Borough of Stockertown's topography may be defined
as a karst topography due to the presence of carbonate rock that generally
consists of dolomite and limestone. The limestone and dolomite are
divided into formations. The carbonate formations present in Stockertown
Borough consist of Epler, Rickenbach, Allentown, Jacksonburg and Leithsville
formations. These formations are susceptible to the development of
solution cavities and sinkhole development. Therefore, anyone considering
developing property within the Borough should be aware of the potential
geological hazards. The regulations contained herein are intended
to minimize the risk of sinkhole occurrence in areas of new development
and on lands adjacent to these developments.
The regulations established by this article shall apply to all
land development or subdivision applications pertaining to commercial,
governmental (except those owned by Borough of Stockertown) and industrial/office
structures, apartment complexes and multiple single-family home developments
with three or more lots.
All single-family homes and the alteration of single-family
homes to include detached structures such as garages, barns and swimming
pools shall be exempt from the regulations established in this section.
As used in this article, the following terms shall have the
meanings indicated:
- CARBONATE ROCK
- Rock types that are affected by dissolution weathering process
caused by slightly acidic groundwater. The most common types of rock
that are categorized as carbonate rock are limestone (calcium carbonate)
and dolomite (calcium magnesium carbonate).
- CAVERN
- Interconnected solution features within the bedrock surface.
- CLAY LINER
- Fine-grained soil that is used in the construction of a liner
that limits the rate of surface water intrusion into the subsurface.
- CLOSED DEPRESSION
- A bowl-shaped depression in the land surface characterized
by internal drainage. A ghost lake is a closed depression which has
visible standing water after a heavy rainfall event.
- DISSOLUTION WEATHERING
- The removal of soluble materials from intact carbonate rock
by slightly acidic groundwater.
- FAULT
- A fracture in bedrock along which movement has taken place.
- FINE-GRAINED SOIL
- Materials that predominantly consist of silt and clay-sized
particles.
- HAZARDOUS MATERIALS (CHEMICAL OR BIOHAZARD)
- As defined and regulated by the PADEP or EPA.
- IMPERMEABLE LINERS
- A liner system that prohibits the infiltration or surface
water into the subsurface.
- KARST
- The terrain that results from the dissolution of carbonate
rock.
- KARST PROCESS
- The dissolution of carbonate rock by slightly acidic groundwater.
- LINEAMENTS
- Aligned topographic features that locate faults and fractures.
- RESIDUAL SOIL
- Soils derived from the in-place weathering of the underlying
bedrock.
- SINKHOLE
- Localized land surface subsidence or collapse due to karst
processes. Sinkholes are categorized as solution sinkholes, collapse
sinkholes and subsidence sinkholes.
- SPRING
- Where water flows naturally out of the bedrock or the overlying
soil mantle onto the land surface.
- TOXIC AND/OR BIOLOGICAL OR CHEMICAL HAZARDOUS MATERIALS
- Biological species or chemical compounds, which are deemed
to be toxic or hazardous by the Pennsylvania Department of Environmental
Protection.
A. All of the following specific requirements shall apply to land developments
and/or subdivisions covered by this article:
(1) No buildings, structures or stormwater management basin shall be
placed in or over the following features if unremediated in accordance
with the terms of this article: sinkholes, closed depressions, lineaments,
or faults.
(2) Building structures and stormwater management basins shall be located
no closer than 100 feet from the rim of unremediated sinkholes, and
no closer than 50 feet from lineaments, faults, or closed depressions.
(3) Outflow from a stormwater management basin and/or postdevelopment
stormwater flows shall not be directed to any of the following carbonate
features: sinkholes, closed depressions, lineaments, or caverns.
(4) Lagoons containing substances defined as toxic and/or hazardous by
the Pennsylvania Department of Environmental Protection are not permitted.
(5) Storage and handling areas for hazardous materials must have impermeable
surfaces designed to contain materials stored/handled from which they
shall be directed to a predetermined collection point.
(6) The land application of hazardous materials is not permitted.
(7) The underground storage of any hazardous materials, except gasoline
and diesel fuel, shall be prohibited.
(8) Groundwater monitoring devices approved by the Borough are required
for all facilities handling hazardous materials.
B. The Borough Council shall not entertain requests for waivers from
the requirements listed above until a Carbonate Ordinance Assessment
Report, as required by this article, has been supplied to the Planning
Commission and the Borough Engineer for their review and comment.
A. All land developments and/or subdivisions covered by this article
shall be evaluated by a licensed professional civil engineer with
expertise in geotechnical engineering or a licensed professional geologist.
Each of said experts being licensed in their field of expertise by
the Commonwealth of Pennsylvania. A list of the engineer's/geologist's
qualifications shall be submitted to the Borough prior to the commencement
of the site's evaluation. The Borough reserves the right to reject
any report that in their opinion was authored by an individual or
firm which does not possess the background to properly assess the
site conditions as they relate to this article. Further, the Carbonate
Ordinance Assessment Report submitted to the Borough must be signed
by the licensed professional civil engineer with expertise in geotechnical
engineering and/or a licensed professional geologist.
B. The format and content of the Carbonate Ordinance Assessment Report
shall include, but not be limited to, the following:
(1) Statement of purpose. This section shall indicate those specific
Carbonate Ordinance standards being addressed in the report and whether
the applicant is attempting to demonstrate compliance or justify noncompliance
with those specific Carbonate Ordinance standards.
(2) Description of existing conditions. This section shall present a
description of existing characteristics of the property with respect
to geology, topography, ground and surface water hydrology, soils,
vegetation, and existing improvements and uses of property.
(3) A map, at a scale no smaller than one inch equals 100 feet and a
contour interval of two feet indicating the location of the property
and all proposed improvements.
(4) The developer/applicant shall submit information for the affected
properties indicating the presence of any of the following carbonate
features: depressions, fissures, lineaments, faults, ghost lakes,
bedrock outcrops, sinkholes, seasonal high water levels, soil mottling,
springs, surface drainage entering the ground, disappearing lakes
or streams and caverns.
(5) A recommended plan for the repair or remediation of surface or subsurface
features that may impact the proposed development as well as the adjacent
improved or unimproved properties.
(6) The information requested above shall be based upon previously published
data and field survey; which may include test borings, excavation
of test pits, air-track probes, and geophysical methods.
C. In addition to the Carbonate Ordinance Assessment Report, the developer
shall also be required to provide the following information:
(1) A plan indicating the existing and proposed drainage conditions,
locations of all proposed private and public sewage disposal systems,
and the location of existing private and public water supplies on
adjoining properties (within 1,000 feet of applicant property).
(2) Type, location and phasing of proposed site disturbance and construction,
as well as proposed future ownership, utilization and maintenance
of the property and the proposed improvements.
(3) Proposed measures to control potential adverse environmental impacts
on groundwater quality and stormwater management resulting from the
development and utilization of the property.
(4) Plans describing the design and construction of the proposed stormwater
management facilities proposed for the project. A description of the
minimum requirements are outlined below.
D. Stormwater management:
(1) All submissions for proposed developments must include a stormwater
management plan prepared in accordance with adopted regulations and
which limits surface water runoff and the intrusion of concentrated
flow of surface water into the subsurface. Facilities that are required
as part of the stormwater management plan include the collection of
all runoff from commercial, office and industrial building roofs into
storm drains by water tight gasketed joint conduits or adequately
lined drainage swales and the collection of surface water flow on
pavements into drop inlets connected to a water tight gasketed joint
stormwater conduit or adequate lined drainage swale. The stormwater
conduit must discharge into lined detention basins.
(2) Approved stormwater conduits include HDPE, PVC. concrete, steel and
cast iron pipe all with watertight rubber gaskets at each joint. The
use of corrugated metal pipe is not permitted. Construction of the
piping system must follow all other applicable ordinances. Where rock
is encountered at or above the planned conduit design grade, the rock
shall be undercut and over excavated a minimum of one foot and backfilled
with a compacted fine-grained soil.
(3) All detention basins in areas of sinkhole prone soil shall be lined.
The liner used in a detention basin may consist of a clay liner, a
composite synthetic and soil liner or a synthetic liner. The type
of liner required shall depend on the condition of the detention basin
bottom and the probability of sinkhole occurrence resulting from the
construction of the detention basin. The use of low-flow channel may
also be required depending on the duration and frequency of stormwater
discharge into the detention basin. Subsurface detention systems must
be in leakproof tanks or piping. The Borough's geotechnical engineer
shall make the final determination as to what is an acceptable form
of liner for the proposed detention basins.
E. Additional items that must be included in the stormwater management
plan include details with regard to the sealing of all pavement curbs
and gutters, manholes and drop inlets.
A. The Carbonate Ordinance Assessment Report must be received by the
Borough when a plan is submitted for preliminary land development
or subdivision approval. However, the report may be submitted at the
time of sketch plan review. Four copies of the report shall be submitted
to the Borough. The report shall be reviewed by the Borough geotechnical
engineer and other consultants as designated by the Borough. Based
on this review, the Borough may require additional information to
be submitted, if the Borough concludes that such information would
be instrumental in assessing the proposed development as it relates
to the Carbonate Ordinance.
B. Approvals required.
(1) Where compliance with this section is required as part of an application
for subdivision or land development approval, the Borough's decision
on whether compliance has been achieved shall be made as part of its
review of the subdivision or land development application.
(2) Where the application is part of a request for zoning permit, the
zoning officer shall issue no permit until he/she receives adequate
written substantiation from the appropriate designated experts referred
to above, the terms of this section, and any conditions imposed upon
the use of the property at the time of subdivision or land development
approval are satisfied.
In carbonate areas, alteration and development of land may be
hazardous with respect to foundation safety of structures, the creation
of unstable land as a result of changes in drainage, and the contamination
of ground and surface waters. Within the limitations of the information
available at the time of the review of individual applications, the
Borough shall attempt to make reasonable judgments as to the applicant's
compliance with the Carbonate Ordinance. Under no circumstances shall
the Borough of Stockertown or any officer or employee of the Borough
or consultant to the Borough assume any liability for any damages
that may result from an applicant's or any interested party's
reliance upon the regulations of the Carbonate Ordinance or any decisions
made by the Borough in the administration of such regulations by an
applicant, developer, and/or any interested party.
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