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The depth to groundwater is approximately 80 ft according to maps published by the San Joaquin County Flood Control and Water Conservation District Groundwater Report, which will be discussed in further detail in the EHD Studies Report. This is a significant distance from the filter bed soil-effluent interface and the bottom of seepage pits down to the water table and should not create adverse effects from P effluent. Effluent test results from both tanks can be compared with data from Small and Decentralized Wastewater Management Systems by Crites and Tchobanoglous. This data is found in Column 4 of Table 3 and is complete mix residential septic tank values(complete mix meaning sludge, scum and clear layers are all mixed together for analysis). The 1:1 data comparison reveals some correlation between the tested constituents, except for Biochemical Oxygen Demand(BODS). The BODS test results indicate that effluent from the Restaurant should undergo significant additional treatment before disposal to the soil. Although the BODS test has its limitations with a number of analytical flaws,the test is still used as a regulatory parameter because it represents the effect potential oxygen depletion may have within the environment. The new septic tanks for this project will have a pump-out schedule,which should be verified by direct observation. Direct observation is the most efficient method since the scum and sludge layers can actually be measured. When 25%-30% of the tank volume consists of these two layers,the tank should be pumped. There is no question that the Restaurant's existing septic tanks must be replaced with new and contemporary grease interceptor and conventional septic tanks for a number of reasons, including structural integrity. The sampling and analysis of the last compartment of the last conventional septic tank also reveal high concentrations of the tested constituents. It should be noted that if the contents of the grease tank and septic tank were commingled,which is typically done,that the two TKN concentrations are not summed together. Their combined concentrations are added and then divided proportionally by the volume from each tank,which is unknown. Constituents of the combined effluents can be approximated by dividing by two to arrive at a final concentration, which is found in parentheses in the third Column of Table 3. The limited Permit information from EHD is inconsequential since the tanks have exceeded their lifespan and will be replaced with tanks that meet Code and are of the most contemporary design for optimum performance. The disposition of the existing leachlines and seepage pits should be addressed under the recommendations of a geotechnical engineer. This concludes the testing, analysis and recommendations of the existing and future effluent receiving soils in the designated disposal area, and the existing wastewater characteristics emanating from the Omelet House Restaurant. yi Respectfully submitted, ofessio �S�aD cher- No. CHESS�NEY CONSULTING oo 5 q - A / � No.75479 Don Ches ey, PE �rar civil s� Registered Civil Eng' eer C75479 °Of Calito�° Page 6 of 7 Chesney Consulting