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IV. CONCLUSIONS AND RECOMMENDATIONS From a theoretical standpoint, for an ADF of 300 gpd, there would have to be 6 people on-site 24/7 contributing an average of 50 gallons of wastewater per capita per day(gpcpd). The anticipated number of on-site people is not expected to approach this population and it may be only the weekends that this population is reached. Due to the current (and future) drought conditions, it is imperative that water use is contained to the absolute minimum for the entire facility. This includes water use within the residential structures as well as landscaping irrigation. Shower timers and low-flow shower heads should be made available to restrict water use from this source. Timers should be set as low as feasible (e.g., 5 minutes). Cooking, dishwashing and laundry should also be closely monitored. — NL § 4.1: The nitrate loading calculations show the resultant effluent from the proposed project will theoretically possess a nitrate-nitrogen concentration under the Federal nitrate Maximum Contaminant Level (MCL) of 45 ppm as nitrate or 10 ppm nitrate as nitrogen. A total nitrogen concentration almost equivalent to domestic sources, as referenced in the scientific literature, was used in the loading calculations. SS § 5.4, 6.83 The shallow soils underlying the subject property show a comparatively fast permeability considering the high percentage of clay content soil. This phenomenon has been observed many times in Tracy area soils that possess a high clay content. Additionally,by uniformly applying the effluent through pressure distribution over the entire area of the filter bed, will allow optimum management by the receiving soils. Reviewing the percolation and more particularly,the soil application rates described in Table 2 on Page 3/4, we find an average application ate of 0.548 gal�ns/ft'-/day that will initially occur at the soil-effluent interface. If we take a maxi in ADF o 00 gp deposited equally over the \ filter bed area floor and the 2.5 ft of sidewaf height(assuming a entire filter bed is full of effluent), this equals 1995 ftZ. Therefore,the application rate is: 300 gpd- 1,995 ftZ= 0.150 gallons/ftZ/day which is 28%of average application rate test result. In other words,the soil will accept 0.548 gallons/ftZ/day blit only 0.150 gallons/ft2/day would flow into the soil under the maximum anticipated ADF. Wastewater flows from a calculated maximum number of on-site people the filter bed soils can manage at 50 gpcp . 1,995 ftZ x 0.548 gallons/ftZ/day= 1,0�3`gallons/da _ 50 gpcpd = 22 people. NLS§ 4.2,,SS6.7. The soil analytical test results show low concentrations of subsurface soil nitrate-nitrogen;along with a decreasing concentration with depth, which theoretically leads to lower nitrate loading. Other sources contributing nitrate to the underlying groundwater in this locale include indigenous soil concentrations from past and present upgradient agricultural fertilizer inputs, septic systems, lawn/landscape fertilization and naturally occurring geological ' deposits. Of these sources, it appears that only past and present upgradient agricultural fertilizer inputs and naturally occurring geological deposits are contributing nitrate to the groundwater underlying the property. Additional nitrate impact to the domestic well may have also originated- from the filter bed serving the small one room apartment which is less than 50 ft from the well. Page-11-