Mine Hill Township City Zoning Code

The applicants filing for preliminary major subdivision or preliminary major site plan approvals and minor subdivision, nonresidential or multistory residential construction from Mine Hill Township shall undertake a geotechnical investigation program. All projects 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 (hereafter the "MGC") appointed by the Planning Board, as authorized by the Municipal Land Use Law, pursuant to this section following a review of the Phase I documents.

The geotechnical investigation program shall be prepared by a professional engineer or geologist with experience in karst terrain or mining areas. The municipality's geotechnical consultant (MGC) shall be similarly qualified to review all projects submitted.

The geotechnical investigation program shall identify the geologic nature of the materials underlying the site.

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 and potential voids due to past mining activities.

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 approvals. Prior to the submission of an application for minor subdivision, preliminary major subdivision or preliminary major site plan approvals, the applicant may, and is encouraged, to consult or meet informally with the municipal geotechnical consultant or the Planning Board Engineer as deemed necessary to receive guidance on their investigation.

The applicant shall complete the Phase I requirements outlined in Subsection C. Upon completion, the applicant shall have the option to submit the information to the Township to obtain an informal review and guidance prior to proceeding with Phase II.

The applicant shall complete the Phase II requirements outlined in Subsection D if required by the Planning Board. Upon completion, the applicant shall have the option to submit the information to the Township to obtain an informal review and guidance prior to proceeding with the on-site geotechnical investigation.

The applicant shall undertake an on-site geotechnical investigation program in accordance with Subsections D and E with observation by MGC where Phase II requirements must be addressed.

The submission of a geotechnical investigation report by the applicant.

MGC review of the geotechnical investigation report and submission of final recommendations to the Township.

Unites States Geologic Survey 7.5 minute topographic quadrangle maps with the parcel identified.

USDA Soil Conservation Service soil survey map indicating soils present on the parcel.

Information from any special reports completed by the New Jersey State Geological Survey, United States Geologic Survey, or the New Jersey Department of Environmental Protection.

Plat locating all past mine and mine opening locations within 500 feet of the property. This plat shall be based upon published mapping and historical searches of past mining activities and shall also address mine depth, angle of descent, and length of all mines, mine openings, and shafts.

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.

Location of all known water production wells and well log information within 1/2 mile of the project.

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, surface water flows and evidence of mine subsidence.

Narrative describing efforts to date if any to seal, cap, or otherwise render existing mines safe for building, development or use of land affected by the mines in question. If mines have been capped, sealed, or made safe, information should be provided that indicates the location and type of work, the dates the work was done, and the contractor that performed the work.

Written narrative describing proposed activity.

If the project includes the storage or manufacturing of toxic or hazardous materials, provide the explanation of the activity and safeguards to be employed.

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, other agencies or from past experience.

General requirements:

Direct testing procedures:

Indirect testing procedures:

Maps, drawings and other documentation:

On-site investigations and tests undertaken pursuant to this chapter shall not begin until the applicant has submitted the appropriate fees as required in § 310-254 and has provided proper notice to the municipality. The applicant shall be responsible for providing, at least 15 days prior to the commencement of any testing procedures, written notice of same to the Municipal Clerk and MGC, which notice shall be transmitted by certified mail, returned receipt requested, or served personally. All site investigations shall be properly closed.[2]

The proposed development site shall be subject to inspect by MGC or designated municipal inspectors at any time. All testing data and results shall be made available to municipal officials and inspectors on demand.

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 Planning Board on the application. All samples are to be stored for possible review by the Township for a period of not less than 10 years by the developer.

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:

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 justifications for the conclusions reached. The report shall, as a minimum, address the following:

Sufficient design, construction and operational information to ensure that the proposed development of the tract will not adversely impact on the health, safety and welfare of the community.

Proof that the proposed method of development on 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.

Specific details ensuring that design concepts and construction and operational procedures intended to protect surface and subsurface waters will be properly implemented to protect against possible sinkhole creation and mine or mine shaft collapse.

Specific details on inspection and monitoring procedures to be following during construction and after project completion.

The following note on the final subdivision plat or final plan for any project: "This site is underlain by limestone formations and/or past mining activity 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."

Acceptable methods.

Lines of surface subsidence. As indicated in Subsection B(3) of this subsection, where existing mine information indicates the land to be developed is traversed by mine workings, in order to eliminate the hazardous impact or voids by ARMs, it shall be required of the applicant (developer) that the line(s) of surface subsidence known or suspected to exist upon the property to be developed shall be excavated to bedrock. Such excavation shall expose in its entirety the vein and all sections thereof from which past mining has removed the ore to the bedrock surface for the full strike length of the vein within the property to at least 25 feet past the last known opening in either direction.

Excavation to bedrock. Excavation to bedrock may, if the applicant (developer) so elects, be preceded by cross-trenching through to bedrock at each subsidence to determine whether such subsidence is caused by collapse into the mined-out void beneath or whether the pit or depression represents initial prospecting to bedrock without subsequent removal of the ore. If no void is located, and the particular pit is 25 feet or more beyond the nearest collapsed void on the line of strike, and there are not further pits on line of strike, then excavation to bedrock along the entire line of strike, as described above, may be terminated at this pit upon written approval of the Township Engineer, MGC, or such other expert(s) as the Township has authorized to supervise such excavation and trenching procedures.

Mining on more than one vein. Wherever the historical record or surface evidence indicates that mining has been carried out on more than one vein within a width of 50 feet, center to center of subsidences, the entire width of the vein system shall be stripped to bedrock, in accordance with the procedure set.

Topsoil and landscaping.

Less than 5,000 cubic yards of void space. Whenever historical data shows or indicates that the abandoned mine or mines occurring within and/or extending into adjoining lands contain less than 5,000 cubic yards of void space, such mines shall be filled in accordance with Subsection B(1) of this subsection, after excavation to bedrock along the line of strike in accordance with the procedures outlined in Subsection B(2) and (3).

More than 5,000 cubic yards of void space. Whenever historical data shows or indicates that such abandoned mine or mines contains void space in excess of 5,000 cubic yards, capping in accordance with the specifications set forth above in Subsection B(1)(b) shall be permitted by the Township in lieu of filling, unless the Township Engineer, MGC, or such other expert(s) which the Township may decide to appoint for the supervision of these procedures for elimination of the hazards resulting from the existence of mining voids, recommends against capping. In determining whether capping or plugging shall be permitted in lieu of filling, the extent of the void areas to be filled, the effectiveness of capping or plugging as compared to filling, taking into consideration the existence or possible existence of pinched areas, timbers, rocks or ore pillars, voids inaccessible to any means of observation or addition, although not intended to be the decisive factor, relative costs of these two acceptable remedial methods shall be considered in all situations where void space is indicated to be in excess of 5,000 cubic yards. Consideration shall also be given to the danger of potential pollution of groundwaters and adjacent and nearby properties by discharge and runoff from any proposed use of individual sewerage disposal systems as a result of their proximity to areas which were formerly mined and which have not yet been filled, it being recognized that filling but not capping or plugging is more effective with respect to the elimination of such pollution problems related to the use of individual sewerage disposal systems.

Supervision of corrective measures. Any and all filling, capping or plugging, as well as excavating to bedrock and cross-trenching or any other tests made to determine the extent of the voids in accordance with the requirements of this § 310-203, shall be performed under the supervision of the Township Engineer, MGC, or such other expert as the Township shall have authorized and designated to supervise and inspect all work relating to these corrective measures to eliminate the hazards presented by these mining voids. The developer shall notify the Township not less than 15 days prior to commencement of any work or procedures relating to filling, capping, excavating to bedrock, cross-trenching or other testing to determine the extent of voids, to permit the Township to provide expert on-site supervision and inspection of the entire process. Failure to so notify the Township and to perform the required corrective work under the supervision and inspection of the designated Township expert shall be reason for withholding final approval of such work and/or final approval of the development plan in question and building permit(s) for the building(s) forming a part of the development in question. In determining the amount of inspection fees required pursuant to § 310-254 of Article XXXI, Fees and Deposits, the cost of this capping, filling or plugging work, excavation work, cross-trenching and other methods of testing used to determine the extent and location of the voids shall be included as a part of the calculation of such fees to assure the cost of such expert supervision and inspection by the Township's designated expert is reimbursed to the Township by the developer.

Survey and monuments. The margins of the line of voids and vein exposures uncovered by the stripping of overburden to bedrock as prescribed in Subsection B(2) and (3) above, as the mandatory preliminary step prior to filling or capping, shall be surveyed at the applicant's expense by a licensed New Jersey land surveyor and tied in to existing permanent survey markers or other acceptable existing points of reference. It shall be the purpose of the survey to establish on the final land surface over such filled or capped or plugged voids their exact location by means of monument or other appropriate lasting material at least three feet in length, four inches to six inches above final ground level. Monuments shall be set on the center line of the original void, one monument at each end of the void and a third halfway between or at twenty-five-foot intervals if the original void was determined to be in excess of 50 feet measured along strike. The surveyor shall keep and maintain careful field notes of all measurements and shall record same on a plan at scale of one inch equals 10 feet, which shall be submitted to the Township as part of the required as-built plans for the development in question. Such survey work shall be under the supervision of such other expert(s) as the Township may designate for such purpose. Further, elevations shall be set to the nearest one-hundredth of a foot on each monument by closed leveling from a permanent point, the elevation of which is known and established from the nearest United States Geological Survey benchmark.

Annual examination. An annual check of the elevation of the monuments shall be conducted at the expense of the owner of the property which is the subject of the development application by a licensed New Jersey land surveyor to determine whether subsidence has occurred. Such checks shall take place each year under the supervision of the Township Engineer, MGC, or such other expert designated by the Township for such purpose, for five years following the original placement of the monuments and each five years thereafter for 25 years within 30 days of the anniversary of the original establishment of the elevations thereof. A written report of the results of such annual check shall be filed with the Planning Board and Township Council. Evidence of subsidence in excess of normal settling four inches or less in the first year, two inches or less thereafter, shall cause the area of known filled or capped or plugged voids and any structure or improvements located thereon to be withdrawn from further use, occupancy or development of any kind completed, inspected and approved by the Township. Such corrective measures shall be initiated only upon submission to the Planning Board of an amended development plan setting forth in detail what measures are proposed, and the approval of such plan by the Planning Board. Such corrective measures shall then proceed to be implemented under the supervision of the Township for such purpose, in the same manner as any improvement required as a part of an approved development plan is installed and/or in withdrawal of the certificate of occupancy for any building located upon the property in question, and shall also constitute a violation of this chapter for which the owner of the property shall be subject to a fine and/or imprisonment in accordance with § 310-271 of this chapter of the Code of the Township of Mine Hill.

No development plan for a use upon Tax Lots 1 and 4 shall be approved by the Planning Board, unless the plans and proposals for filling and/or capping the mine voids on said Lot 4 include also filling and/or capping of the voids located upon said Lot 5. No final approval of any such development plan shall be granted unless all the mine voids located on both Lot 4 (including Lot 1) and Lot 5 (Block 1201) have been filled, capped or plugged or performance guarantees to assure such capping or filling have been posted by the applicant in accordance with § 310-205A.

The applicant for the development of Lot 4 shall furnish satisfactory proof to the Planning Board that permission has been secured from the owner of said Lot 5 to perform the required filling, capping or plugging of the mine voids located on said Lot 5.

In the event the applicant for development of Lots 1 and 4 establishes to the satisfaction of the Planning Board that, despite diligent effort on the part of applicant, permission upon reasonable terms cannot be secured from the owner of Tax Lot 5 to fill, cap or plug the mine voids located on said Lot 5, the following additional restrictions shall control the development of Lots 1 and 4 for conditional use:

If the subject property and the adjacent property are owned by the same person or persons, then the applicant shall be required (in accordance with the procedures established herein for and as a part of securing preliminary and final approval of a conditional use in a mining district) to eliminate the hazardous impact of the subsurface voids left by such prior mining activities upon such adjacent property by capping, filling or plugging such voids upon such adjacent property in accordance with procedures and requirements of § 310-203 above to the limit of such voids or for a distance (along each line of depressions) of 500 feet into such adjacent property measured from its common boundary line with the property which is the subject of the use application. The Planning Board shall not grant final approval to a development plan involving a use in any of these mining zones until the hazards of the voids on any such adjacent property within 500 feet of the subject property have been eliminated or performance guarantees to insure the required capping, filling or plugging on such adjacent property is properly completed have been posted in accordance with the requirement of said subsection.

All the requirements of § 310-203 shall be equally applicable to the elimination of mining hazards located upon such subject property.

If the adjacent property upon which mining activity was conducted within 250 feet of the common boundary line with the subject property is not owned by the same person or persons who own(s) the subject property, the adjacent property shall nevertheless be rendered safe from the hazards of the prior mining activities to the extent and in the same manner as required for the subject property immediately above where both properties are owned by the same person(s) as a condition of final approval of the pending development plan, unless the applicant for development establishes to the satisfaction of the Planning Board that, despite diligent effort on the part of applicant, permission upon reasonable terms cannot be secured from the owner(s) of the adjacent property to fill, cap or plug the mine voids located thereon (or to perform the tests and activities described above to determine whether or not capping and/or filling is required).

In the event the applicant cannot secure permission from the owner of the adjacent property to fill, cap or plug the mine voids located thereon for a distance of 500 feet into the adjacent property (or to take the necessary steps to determine whether capping and/or filling are necessary in accordance with the standards and requirements of this chapter), then the following additional restrictions shall control the development of the conditional use upon the property which is the subject of the development application: