COMPLIANCE INFO_1990-1998 - Laserfiche WebLink

Home Browse Search

SITY OF TRAA quality remains within the limits set by these criteria. As specified in the WDR's, PCB analyses are presented, and levels are well below those specified in Title 22 for hazardous wastes. Sludge treatment meets standards for a process to significantly reduce pathogens. Sludge has been air-dried on underdrained, sand drying beds since October, 1992, for over three months. This included the summer months, when temperatures are well in excess of the stipulated 2 months at 0 degrees C. Loading Rates and Calculations (2) Sludge loading calculation methods are detailed in Table 4. Agronomic rates of sludge are calculated by matching the crop nitrogen requirement with a sludge load that will provide the amount of available nitrogen during the year after the sludge is applied. This quantity of sludge specifies loading rates for other nutrients and heavy metals. Considered in the calculations are Nitrogen transformations, including mineralization, nitrification, denitrification, and ammonia volatilization Sludge properties, such as moisture content, density, and sand content (from sand drying bed floors) Analytical results for this year's sludge Quantity of sludge available this year Crop nitrogen requirements Resulting sludge loading rates for each field on the site are shown in Table 5. Sludge loading rates have varied from the plant nutrient application rates shown in Table 10 of the SMP for sugar beets and almonds. KL Farms needs 125-150 lbs/acre of nitrogen to grow their desired yield of beets instead of the 60 listed in the SMP. K&L Farms also needs approximately 200-300 lbs/acre of nitrogen when the sludge is applied to their mature almonds. These values have been confirmed with the fertilization consultant used by K&L Farms. Actual loading rates are approximated here, and will be presented in the post -application report. Annual and cumulative loading of nutrients and metals are shown in Table 6. None of the cumulative or annual loadings are in excess of the criteria. Our agricultural consultant with CH2MHi11 produced our first pre -application report, dated Oct. 8, 1991. In this, he said that phosphorus is relatively immobile in the environment and large, single applications of phosphorus can be considered agronomic, and do not necessarily pose an environmental threat. He also said in the same report that zinc is deficient on the K&L soils, and an annual application rate of approximately 10 lbs per acre should be helpful. This reduces the requirement for supplementary zinc application and, in our case, zinc accumulation in the 6 Telephone 209/836-1650 3900 Holly Drive Tracy, California 95376