Section 15.212 - Depth to Groundwater(1) The minimum vertical separation distance between the bottom of the stone underlying the soil absorption system above the high ground-water elevation shall be (a) four feet in soils with a recorded percolation rate of more than two minutes per inch;(b) five feet in soils with a recorded percolation rate of two minutes or less per inch.(2) For systems with a design flow of 2,000 gpd or greater, the separation from high groundwater as required by 310 CMR 15.212(1) shall be calculated after adding the effect of groundwater mounding to the high groundwater elevation as determined pursuant to 310 CMR 15.103(3).Amended by Mass Register Issue 1499, eff. 7/7/2023.Amended by Mass Register Issue 1501, eff. 7/7/2023.