Laserfiche WebLink
!~ ~: <br />Machine tamping, rolling or hydraulic compaction of final cover shall not be <br />permitted, however, hand tamping may be allowed where necessary to stabilize the <br />soil to prevent erosion or the intrusion of extraneous water. <br />B. Ripped Base Beds: <br />Ripped base beds shall be permitted in areas where weathered, decomposed bedrock <br />or other unsuitable soil or rock is present, and if the excavation of the unsuitable <br />material can be accomplished. The Registered Professional Engineer shall specify the <br />fill material that will comprise the suitable sail. The absorption field size shall be <br />determined from the original percolation test or from percolation tests of fd! soils, <br />whichever is greater. Percolation tests of the fill soils shall be done in accordance <br />with Section 4.03 and the test results must be submitted to the local health <br />deparmmett. T'he design engineer must verify that the compaction of the fill soils is <br />adequate in his opitrion. Compaction of soil under the gravel shall be a minimum of <br />80% of relatively density of optimum moisture. <br />C. Absorption or Seepage Pits: <br />Absorption or seepage pit systems shall be designed by an Registered Professional <br />Engineer Absorption or seepage pits having adequate soil absorption may be <br />permitted by the local health departments as an alternative, where absorption fields <br />aze impractical and the subsurface conditions are otherwise suitable for pit <br />installations. The capacity of the pit shall be computed on the basis of percolation <br />tests made in each stratum penetrated. The weighted average of the results shall be <br />used to obtain a design figure. Soil strata in which the percolation is slower than <br />thirty (30) minutes per inch shall not be used for absorption or seepage. The effective <br />area of the pit is the vertical wall area (based on dug perimeter) of the pervious strata <br />below the inlet. No allowance shat] be made for impervious strata or bottom azea. <br />Pits shall be separated by a distance equal to three (3) times the greatest lateral <br />dttnension of the largest pit. For pits over twenty (20) feet depth, the minimum space <br />between pits shall be twenty (20) feet. Pits shall be provided with both vertical <br />sidewall and top supporting structural concrete or other material of equal structural <br />integrity. Adequate safety protection shall be provided to protect against personal <br />injury during construction or use. <br />D. Drv Wells: <br />Dry wells may be permitted by the local health department. They shall be filled with <br />clean, graded rock which may range in size from '/x to 2 '/z inches in diameter. The <br />rock shall extend from the bottom of the pit to at least two (2) inches above the inlet <br />pipe. At least one (1) four (4) inch perforated vertical stand pipe will be attached to <br />the end of the distnbution line with a tee fitting. It shall extend to the bottom of the <br />dry well and up to the finished grade and fitted with a removable cap to be used as an <br />inspection pipe. The absorption azea of the dry well shall be computed on the basis <br />of percolation rates, or the long term acceptance rates of each stratum penetrated. <br />The weighted average of the results shall be used to obtain a design value. The <br />effective azea of the pit will be calculated by adding the area of the side walls below <br />42 <br />