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FALL CREEK ENGINEERING,INC. a certified laboratory) to provide further evidence and guidance regarding management of pH buffering capacity. Soil microbial communities are typically quite diverse in genera and function and are adaptable to a wide range of chemical and physical perturbations of soil. While a pH range of 6.5 to 7.5 is considered optimal for most species, the most critical factor influencing microbial community size and activity is organic matter availability. Highly acidic (<4.5) and alkaline (>8.2) conditions inhibit bacteria, but numerous bacteria are found in soils of pH=3. Fungi are much more adaptable and many species have a wide tolerance range (2.5 to 9.0). The most ecologically important pH-sensitive bacteria are those responsible for nitrification (inhibited<6.0) and it could be argued that slight temporal inhibition of nitrification in soils would further minimize nitrate formation and subsequent transport. Microbial community structure tends to reflect the diversity of environments. While it can be argued that any perturbation ranging from fertilization to tillage can have large temporal effects on microbial community structure, functions related to organic carbon oxidation and sequestration are common to a diverse group of soil heterotrophs. Therefore, it is very unlikely that the application of effluent with the properties shown, and as only a fraction of the total moisture requirement for grapes and grains could have significant medium-to long-term effects on microbial fiinction. Perhaps the most significant short-term impact from effluent application on microbial communities would be a rapid temporal shift to species (predominantly bacterial) most capable of rapid oxidation of sugars, more complex carbohydrates, amino acids, etc. found in the effluent. In conclusion there is little evidence presented in the WDR or the wastewater analysis data provided that suggests agronomically appropriate levels of effluent to grape and grain crops will result in negative impacts on groundwater quality due to either the increased solubilization or transport of manganese, iron, and aluminum. Typical agronomic practices will maintain the pH and buffering capacity of the surface soils, while enhancing nutrient salt uptake and removal from the soil system. This finding should be revised to more accurately describe the wastewater quality and expected conditions that will occur with the application of wastewater in these areas. 51. It is important to note that the FAO Agricultural Water Quality Guidelines apply to the long term use of water applied to a crop. The WDR implies that process wastewater will be the main source of water applied to crops. However,under the proposed land application plan, only 42% of the applied water to the vineyards will be wastewater, and the remaining irrigation supply water will be either well water or rainfall. Similarly, oats will only receive approximately 33%of the irrigation water demand from wastewater, and the remaining supply will be from rainfall. It is important to note in the WDR that irrigation of crops will be conducted using a mixed regime of water sources. This is an important aspect of the proposed wastewater disposal scheme that will be employed to minimize the accumulation of salts and to maintain optimum soil and crop conditions in the LTU. A new finding should be added that reflects the use of mixed regime water sources. 6