1. Minor Subdivisions. Those applications proposing the use of onlot wells and/or onlot sewage disposal systems in areas underlain by karst topography which contains sinkholes or is sinkhole-prone shall conform to the following guidelines:
A. Storm water from roadways, parking lots, storm sewers, roof drains or other concentrated runoff paths shall not be discharged into sinkholes.
B. Sinkholes shall be protected by diverting surface water away from a sinkhole or planting and maintaining a dense filter strip of suitable vegetative material (e.g., tall grasses) at least 30 feet in width in such manner and location as to disperse and slow the runoff and to promote the maximum possible filtration of both solid and dissolved impurities.
C. Sinkholes with a capacity sufficient to receive an appreciable volume of storm water, as determined by the Township, must be posted in a clearly visible manner. Such notice shall explain the sinkhole designation as contamination prone and shall prohibit disposal of any material including but not limited to refuse, rubbish, hazardous wastes, organic matter or soil.
D. If increased runoff is to be discharged near a sinkhole, even in filtered condition, a geologic assessment of the effects of such runoff shall be made and submitted with the stormwater management plan specified in § 22-409. Such discharge shall be prohibited if it is determined that this runoff poses a hazard to life, property or groundwater resources or causes increased land subsidence.
2. Commercial Land Development and Major Subdivisions. Those applications proposing the use of onlot wells and/or onlot sewage disposal systems for commercial and major subdivision purposes in areas underlain by karst topography or carbonate bedrock units which are sinkhole-prone shall require the preparation of a preliminary hydrogeologic study. Such preliminary hydrogeologic study shall be conducted by a qualified hydrogeologist and consist of the following minimum requirements:
A. A topographic map showing the location of the site, as well as the proposed onsite sewage disposal systems and wells. Narrative descriptions of these systems shall also be furnished.
B. A map showing the existing sinkholes, bedrock and surficial units, soils and a description of the geologic conditions on and around the site.
C. A map and narrative description of the area that will be impacted by the use of the proposed well(s) and/or onlot sewage disposal systems. Accompanying the map and narrative will be an analysis of the well(s) impact upon the ground water of the region and any anticipated water quality/quantity impacts to areas located downgradient and/or along any geologic fracture, trend or fault. These anticipated impacts shall also consider existing and potential land uses located within the affected area.
D. Should it be determined that the proposed use(s) would result in a degradation of the groundwater at nearby properties, the study shall present measures to be employed to mitigate these adverse impacts.
E. Where existing sinkholes are located, no stormwater runoff shall be discharged into or near the sinkhole and a filter strip shall be established as a buffer. Specifications and mapped description for such a buffer shall be furnished by the developer.
(Ord. 3/9/1993A, § 413)