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Staff Report -4— Waiver 4— Waiver of WDRs for Small Food Processors that crush over 80 tons of grapes would choose to haul off their wastewater. As stated above, crushing 80 tons of grapes produces approximately 100,000 gallons of wastewater. The average hauling/disposal rate charged by septic haulers is 25-30 cents/gallon of wastewater, leading to an annual cost of$25,000 to$30,000 to dispose of wastewater from a winery crushing 80 tons of grapes/year. If a winery has available land, it would probably be more cost effective to install an irrigation system to dispose of the wastewater at reasonable agronomic and hydraulic loading rates, than to tank/haul the wastewater. Based on this understanding, the waiver has been revised to state that it applies to any winery or small food processor, regardless of size, that chooses to tank/haul its wastewater. In addition, staff are recommending that the Regional Board consider rescinding General Order No.R5-2003-0029, the General Waste Discharge Requirements for the On-Site Storage and Off-Site Disposal of Wastewater Generated by Commercial Wineries Within the Central Valley Region. The net result of this action is that any small food processor that tanks/hauls its wastewater will be covered by a waiver,the Discharger will only pay a one-time filing fee instead of an annual fee,and will only submit an annual monitoring report instead of semi-annual monitoring reports. The waiver has been revised to include all applicable Discharge Specifications from General Order No.R5-2003-0029. Therefore, the waiver will protect water quality to the same degree as the General Order. Wastewater Disposal Methods This waiver is only applicable to those discharges of waste which have little potential to create nuisance conditions (odors, mosquitoes, flies,etc.) and have little potential to impact water quality. There are four main constituents in winery and other food processing wastewater that may impact water quality. As shown in the table below,the strength of winery waste is variable, depending on the season and the particular operation being performed. Monitoring data submitted to the Regional Board shows that these concentration ranges are fairly constant, regardless of the size of the winery. The peak wastewater strength and volume is generally during the grape crushing season,which takes place from about August to October. Other operations such as cleaning equipment and tanks can generate high strength waste streams. It also be should be noted that many small wineries have reduced their water use, and therefore they generate higher strength wastewater(i.e.,through less dilution). The wastewater strength from other food processors is also presented in the table. This data is from Reports of Waste Discharge and monitoring reports submitted by food processors currently regulated by the Board, and includes wastewater from fresh fruit packers (apple, cherry, apricot), prune dehydrators, seed producers, and a producer of soy/rice products. Other Small Domestic Groundwater Winery Food Sewage Criteria Constituent Units Concentration Processors Concentration PH pH units 2 - 11 5 -9 6 - 8 6.5-8.5 BOD mg/I 300- 12,000 1 -2,000 100 -400 None TDS (salts) mg/I 80-6,000 400-2,300 150- 1,000 450 Nitrogen mg/1 1 - 50 1 - 17 20 - 50 10 The application of wastewater to cropland at reasonable hydraulic and agronomic loading rates is a long-standing practice that is typically protective of the underlying groundwater. The nitrogen in the wastewater,as well as some of the salts, will be utilized by the crops. In a well-aerated soil,the