A. No alteration, disturbance or construction of any type shall be approved or initiated, and no application for final approval shall be approved for SITES having any portion of their area proposed for development on or within fifty (50) feet of any STEEP SLOPE ([25% or greater) until any other applicable Federal, State, COUNTY, or TOWNSHIP regulations have been satisfied. [Amended 5/12/2008 by Ord. No. 390]
B. No FINAL APPROVAL of the APPLICATION FOR DEVELOPMENT shall be given until all required COMMONWEALTH and COUNTY and SEDIMENTATION and EROSION control permits have been issued and submitted to the TOWNSHIP.
C. The DEVELOPER shall clearly delineate all STEEP SLOPE area(s) on certified survey maps, with two (2) foot contour intervals submitted with all applications for development. if no slopes of 15% or greater exist, the DEVELOPER shall certify the non-existence of such features. The areas to be delineated are: 15-25% slope and slopes greater than 25%.
D. No building sites shall be designated or improved in STEEP SLOPES areas except as permitted by this ordinance and Chapter 208, Marshall Township ZONING ORDINANCE.
E. When development activity is proposed on areas identified in section(C) above, a geotechnical investigation and report shall be required to assess the short and long-term stability of the site and the possible effects on neighboring properties of developing the proposed site in the proposed manner. These areas and the proposed development shall be investigated and documented in a statement by a registered Professional Engineer prior to final approval. This slope investigation shall determine the engineering characteristics and physical properties of the slopes, soil deposits and underlying rock strata, which are proposed for use in structural foundations. Materials used for earthwork construction shall be similarly evaluated.
F. A geotechnical investigation report prepared by or under the direction of a professional engineer, experienced in soil and foundation engineering, shall be submitted for site plans located in areas of STEEP SLOPE and for such other sites where special soil or water conditions are deemed by the TOWNSHIP ENGINEER to be potentially hazardous. The required soils report must be prepared in accordance with this ordinance and other applicable commonwealth or COUNTY regulations.
G. The SITE geotechnical investigation should include, but not be limited to, the following detailed factual information, analysis, and recommendations:
1. Surface Features - Surface contours, old construction, rock outcrops (if any), watercourses, ditches, ponds, wooded areas, filled-in areas, and old slide areas.
2. Hydrologic Features - The presence of seepage zones, depth to groundwater, and the possible fluctuations with the seasons.
3. Subsurface Features
(a) A plotted, horizontal and vertical record of the stratification of the soil and rock deposits.
(b) Information on the relative density of granular soils in the different strata and on the consistency of cohesive soils.
(c) Information on subsurface geologic features and past mining activity including depth of overburden.
4. Exploration Methods - Physical explorations can be carried out by several methods. Field explorations should follow the applicable standards or the procedures and practices recommended by the American Society for Testing and Materials (ASTM). It is generally sufficient to secure soil samples at intervals of five feet in depth or at changes in the material. The intervals should be determined by such conditions as the soils encountered and/or the type of structure.
5. The spacing and depths of borings should also be based on SITE conditions and proposed construction. Maximum spacing between borings should not exceed 250 to 300 feet. One boring for every 6,000 to 10,000 square feet of BUILDING area should be a minimum for a high-rise structure, and a minimum of one boring per structure is recommended for single-family residences.
6. Groundwater Measurements – Information is required on groundwater elevations, including depth of permanent and perched water tables. Water levels should be determined on completing the boring and again, approximately 24 hours later.
7. Classifications and Descriptions - Direct observation of soils samples from various depths and locations will be required for correlation with the known geology of the area. Classification and description of soils will be done by the Unified Classification System (ASTM Specification D2487), and by the Visual Manual Identification Procedure (ASTM Specifications D2488).
8. Laboratory Testing - The laboratory testing program should be dependent upon the characteristics of the soils and the anticipated geotechnical problems analysis.
9. The recommendations of all such investigations and reports of STEEP SLOPES and other identified soil or water condition hazards shall be reviewed by the TOWNSHIP engineer. incorporation of said recommendations may be required as conditions for preliminary approval and/or final approval.
10. All public and private roads, bridges, utilities and other facilities shall be located, designed and constructed to avoid STEEP SLOPE areas or to withstand any anticipated soil or rock movement.
11. ROAD and utility alignments and grades shall minimize cuts and fills.
12. Hazardous slope conditions that may be present on a site must be corrected prior to completion of the development.
