Rules for grading, grubbing, and stockpiling land

Slope Control.Height. Where a cut or fill is greater than fifteen (15) feet in height, terraces or benches shall be constructed at vertical intervals of fifteen (15) feet except that where only one (1) bench is required, it shall be at the midpoint. The minimum width of the terraces or benches shall be at least eight (8) feet and provided with drainage provisions to control erosion on the slope face and bench surface.Cut Slopes. Under the following soil conditions, no cut may be steeper in slope than the ratio of its horizontal to its vertical distance as shown below. One-half (1/2) horizontal to one (1) vertical in unweathered rock or mudrock.One (1) horizontal to one (1) vertical in decomposed rock.One and one-half (1-1/2) to one (1) vertical in soils of low plasticity, cuts of any height in highly plastic soils shall be as recommended in the engineer's soil report.Fill Slopes. Fill using non-expansive material shall not be steeper in slope than the ratio of two (2) horizontal to one (1) vertical, or one and one-half (1-1/2) horizontal to one (1) vertical in areas recommended in the engineer's soil report.Distance from Adjoining Property Line. The horizontal distance from the top of a cut slope or the bottom of a fill slope to an existing adjoining property line shall not be less than as follows:Height of Cut or FillDistance from Adjoining Property Line (in feet)0 feet to 4 feet2More than 4 feet to 8 feet4More than 8 feet to 15 feet6More than 15 feet8Modifications. These requirements may be modified by the County Engineer when cuts or fills are supported by retaining walls approved by the Engineering Division or when the permittee submits an engineer's soils report stating that the soil conditions will permit modifications, or when warranted by additional engineering data.Area Opened. The maximum area of land that may be opened for grading or grubbing at any one (1) time is ten (10) acres. The area of land that may be opened shall not exceed ten (10) acres unless detailed plans and schedules are approved by the County Engineer that document or demonstrate the ability to control dust, erosion and pollution and to minimize storm damage, and authorization is issued by the State of Hawai'i Department of Health under the provisions of the National Pollutant Discharge Elimination System (NPDES) Permit program. The permittee's drainage and erosion control plan shall be designed to ensure that the grading or grubbing activities will not cause or contribute to a violation of the State's basic water quality criteria (Hawai'i Administrative Rules, Section 11-54-04). There shall also be procedures established for the maintenance of, inspections, and modifications to the system of erosion and sediment controls for the site as prescribed and approved by the County Engineer to prevent water quality violations. To control fugitive dust, measures such as the use of water wagons, sprinkler systems and dust fences shall be used to minimize any visible dust emissions from the construction site. If these measures do not prove to be effective, or if significant dust, erosion, pollution or storm damage problems occur, the County Engineer shall reduce the permissible open area to reasonably control and minimize such dust, erosion, pollution or storm damage problems.Fills. The requirements of Paragraphs (1), (2), and (3) of this Subsection may be modified if the permittee submits an engineer's soils report recommending criteria for the proposed fill for its intended use, and the modifications are approved by the County Engineer.Fill material shall be selected to meet the requirements and conditions of the particular fill for which it is to be used. The fill material shall not contain trees, timber, plants, shrubbery, grass, and woody vegetation matter. Fill within the shoreline setback area as established by the Planning Department shall be of material compatible with the marine environment. The use of soil as fill is prohibited within any shoreline area, as defined by Sec. 205A-1, Haw. Rev. Stat., except for sand, as defined herein.Preparation of Ground Surface. Before placing fill or stockpiling, the natural ground surface shall be prepared by removing the vegetation and, if required by the County Engineer, shall be notched by a series of benches or have subsurface drains installed, or both. No fill shall be placed over any water spring, marsh, refuse dump, nor upon a soft, soggy or springy foundation.Placement and Compaction. Fill materials shall be spread and compacted in a series of eight (8) inch layers (maximum) when compacted. Except for slopes, the fill shall be compacted to ninety percent (90%) of maximum density as determined by the most recent ASTM Soil Compaction Test D1557 or AASHO T180.Vegetation. Whenever feasible, natural vegetation and top soil shall be retained. Trees, timber, plants, shrubbery and other woody vegetation, when displaced shall not be stored or deposited along the banks of any stream, river or natural watercourse. After being displaced, the vegetation shall be disposed of or removed from the site at the earliest reasonable time, conforming to State Health Department Rules and availability of County or private solid waste facilities as they exist at that time, except where the County Engineer allows for the mulching of the greenwaste and its re-deposit onto the site.Drainage Provisions. Adequate provisions shall be made to prevent surface waters from damaging the cut face of an excavation or the sloped surfaces of a fill. Proper drainage shall be provided to prevent the unwanted accumulation or retention of surface water. The County Engineer may require the drainage structures and pipes to be constructed or installed, which will reasonably minimize erosion damage and satisfactorily carry off surface waters. The flow of any existing and known natural underground or surface drainage shall not be impeded or changed so as to cause damage to surrounding properties.Debris Prohibited. No person shall perform any grading operations so as to cause falling rocks, soil or debris in any form to fall, slide or flow onto adjoining properties.No grubbing or grading shall take place within the Special Management Area (SMA) or the Shoreline Setback area, without first obtaining approval of an SMA and/or Shoreline Setback Variance permit, as required by the County Planning Department. Any grading of a coastal dune within the shoreline area or a frontal dune is prohibited, except that where a permit is issued under this Article, sand may be imported and placed on the area of the coastal dune mauka of the shoreline to rebuild or enhance the protective capacity and environmental quality of the coastal dune.Hours of Operation. No work shall be done between the hours of 7:00 p.m. and 7:00 a.m. Monday through Friday, and no work shall be done on Saturdays, Sundays and holidays without the prior written permission of the County Engineer.Water and Air Pollution Control. All operations shall be performed in conformance with the applicable provisions of the Water and Air Pollution Control and Water Quality Standards contained in the Administrative Rules, Department of Health, State of Hawai'i, on Air and Water Pollution Control and Water Quality Standards.Report after Grading. When grading involves cuts or fills for which an engineer's soils report is required, the permittee shall submit a certification from the soil's engineer that the work was done in conformity to this Article and the engineer's soils report. The report after grading shall contain information including but not limited to the following: engineering data of the fill material used; how it was placed and compacted; moisture during compaction; compacted density; preparation of the ground to be filled on; subdrains and other pertinent features of the cut or fill necessary for its stability.Notification of Completion. The permittee or his/her agent shall notify the County Engineer or his/her representative when the grading operation is ready for final inspection. Certificate of completion shall be given upon completion and inspection of all work including installation of all drainage structures and their protective devices, completion of all planting in conformance with the approved plans and specifications, and the submission of the required reports and as-built grading plans whenever the completed work contains approved deviations from the original plans. Certificate of completion shall not be construed as relieving permittee from any of the requirements set out in Section 22-7.16.