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LUCCA WINERY SOIL SUITABILITY & NITRATE LOADING STUDY MAY 2013 V. CONCLUSIONS AND RECOMMENDATIONS It is recommended, that although the minimum leach field length consists of 3-85 foot leachlines (per EHD Document 42-01-004), as the necessary length of leachline, this application may not require that entire length. Per EHD Document 42-01-004, Section - 9.3, Table 1 , a three bedroom home requires 3-80 foot leachlines in Sandy Loam Soil. This application of the septic system applies to two facilities with a combined three toilets, no employees and will be used on weekends during the wine processing period (late summer into early fall). The main use of the restrooms will be mostly limited to that period of time. The evaluation computed in Section III was for bathrooms that were in use every day during the year, and included a tentative Phase II facility that might not be constructed. Furthermore, the restrooms only consist of one toilet and one sink each that will provide the wastewater to the septic system. Upon evaluation of this information, it is recommended that the septic system be no more than 2-80 foot leachlines rather than 3-90 foot lea— chffnas. Were the construction of the Phase II facility incorporate more employees, or built for a larger event than wine tasting, the leachfield can be expanded since the proposed leachfield area and 100% replacement areas are able to accommodate expansion. SSS§ 5.4, 6.8. The soils underlying the area proposed for wastewater effluent disposal show acceptable permeability at the shallow depths of 36 to 84 inches below grade. _.. From the soil chemistry test results, it appears there is denitrification that occurs in the soil. NLS§ 4.2, SSS§ 6.7. Since this application is for a proposed wine making facility, additional nitrate loading at around the site is of concern and will be appropriately mitigated. Winery wastewater and solids will be disposed of in the manner prescribed in the Central Valley Regional Water Quality Control Board Report of Waste Discharge Order No. R5-2009-0097-0075. Wastewater from the winery will be collected into a 2,000 gallon concrete tank and then pumped and distributed throughout the 20-acre Peach Orchard. Further, solids from the wine making process will be disked and incorporated into the soil throughout the 20-acre Peach Orchard. Upon evaluation of the operations of the facility and the proposed septic system, the nitrate loading impacts will be mitigated appropriately. NLS§ 4.1. The nitrate loading calculations demonstrate that if the toilets were flushed a total 72 times per day (1 .5 gals/flush x 72 flushes + 0.25 gals for hand washing x 72 trips = 126 gpd ADF), the nitrate loading remains well below the Maximum Contaminant Level (MCL). Considering that it is evident that there is denitrification occurring in the soil, as the depth increases; the minimal amount of nitrates that are being introduced into the soil, will be mitigated through denitrification as the wastewater is permeated through the soil. Page 114