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I <br />f <br />03 Gl�.j OF T�qO� � <br />CITY <br />OFT <br />Utilities Division <br />�@, XX ; + 3900 Holly Drive Telephone: (209) 836-1650 <br />9 INCORPOVOC, Tracy, CA 95376 Fax:. (209) 836-0932 <br />Loading Rates and Calculations (2) <br />Sludge loading calculation methods are detailed in Table 4. Agronomic rates of sludge are <br />calculated by matching the crop nitrogen requirement with a sludge load that will provide <br />the amount of available nitrogen during the year after the sludge is applied. This quantity <br />of sludge specifies loading rates for other nutrients and heavy metals. Considered in the <br />calculations are <br />Nitrogen transformations, including mineralization, nitrification, <br />denitrification, and ammonia volatilization <br />Sludge properties, such as moisture content, density, and sand <br />content (from sand drying bed floors) <br />Analytical results for this year's sludge <br />Quantity of sludge available this year <br />Crop nitrogen requirements <br />Resulting sludge loading rates for each field on the site are shown in Table 5. Sludge <br />loading rates have varied from the plant nutrient application rates shown in Table 10 of the <br />SMP for sugar beets and almonds. K&L Farms needs 125-150 lbs/acre of nitrogen to <br />grow their desired yield of beets instead of the 60 listed in the SMP. K&L Farms also <br />needs approximately 200-300 lbs/acre of nitrogen when the sludge is applied to their <br />mature almonds. These values have been confirmed with the fertilization consultant used <br />by K&L Farms. Actual loading rates are approximated here, and will be presented in the <br />post -application report. <br />Annual and cumulative loading of nutrients and metals are shown in Table 6. None of the <br />cumulative or annual loadings are in excess of the criteria. <br />Our agricultural consultant with CH2MHill produced our first pre -application report, <br />dated Oct. 8, 1991. In this, he said that phosphorus is relatively immobile in the <br />environment and large, single applications of phosphorus can be considered agronomic, <br />and do not necessarily pose an environmental threat. <br />He also said in the same report that zinc is deficient on the K&L soils, and an annual <br />application rate of approximately 10 lbs per acre should be helpful. This reduces the <br />requirement for supplementary zinc application and, in our case, zinc accumulation in the <br />