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Farea nnemore and Hantzsche paper, they discuss three options to consider as potential methods of the mounding phenomenon. The first is increasing the size of the disposal field. Based average daily flow calculations found on Page 14, it is anticipated the disposal area is t in size to accommodate the projected flow volumes after complete build-out. The disposal ased on mathematical computations for sizing found in the S.J.C. Sewage Standards and EHD parameters. The second method is elongating the shape of the area covered by the disposal field. As noted on the design plans, the filter bed is elongated in a 9.5:1 length-to-width ratio. Thirdly, operating the field intermittently should decrease the mounding effect. As noted in the filter bed design,there are two separate filter bed disposal areas. Effluent will be pumped by two separate pumps that will alternate between the two filter beds, thus creating intermittent dosing of each bed. If it is determined at some point in the future, that mounding effects are preventing proper effluent treatment and disposal, the area designated as the 100%replacement areas may have to be activated. These reserve areas are located directly to the east and to the south of the primary disposal area for the ELF, and to the south and west for the WLF. Activation of the 100%reserve area may occur prior to attaining the projected 1,586 gpd effluent flow volumes after the phased completion and full occupancy. However, this can be considered unlikely. E. SURFACE WATER INFORMATION The surface water retention pond for the existing and future development of the project will be at the southern end of the project, as denoted on the Site Plans. There should be no impact to impoundment water from the proposed two filter beds due to a separation distance of approximately 220 feet from the WLF and over 800 from the ELF. Depending on the directional flow of the upper groundwater aquifers, the retention pond is either upgradient or crossgradient to the future filter bed. If the groundwater directional flow is northeast,percolating rainwater from the basin into the top aquifer mixing layer may create a dilution effect to the downgradient percolating septic system effluent. Groundwater dilution affects can only be truly discerned with complicated groundwater monitoring and modeling. According to a scientific paper authored by Shaw and Turyk(1994),reduction of nitrate concentrations in groundwater can occur primarily through dispersion, or by percolating rainwater recharge. Climatic Data: Rainfall versus Evapotranspiration NLS§3.2 It is generally and scientifically accepted that when precipitation exceeds evapotrans- piration(Eto), deep percolation of surface rainwater may occur. Evapotranspiration refers to water evaporation that takes place both at the soil surface and transpiration by plants, and is defined as water loss from a large field of 4-to-7 inch tall, cool-season grass that is not water stressed. The following chart illustrates rainfall and evapotranspiration for the Stockton area. Precipitation data was obtained from the Soil Survey of San Joaquin County. The conservative"2 years in 10"data was used and not the"average rainfall'data. Evapotranspiration data was obtained from the California Irrigation Management Information System (CIMIS): 11 Chesney Consulting