SITE INFORMATION AND CORRESPONDENCE CASE 2

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0 WASTE DISCHARGE REQUIREMENTS ORDER NO. -3- PAT MITCHELL AND CALIFORNIA NATURAL PRODUCTS WASTEWATER TREATMENT AND DISPOSAL FACILITY SAN JOAQUIN COUNTY 14. The trickling filter operates at 2,500 gpm. Wastewater is recycled approximately ten times through the filter. Because the process wastewater is high in BOD and low in nitrogen, the Discharger adds ammonium nitrate to the wastewater as a nutrient to optimize BOD removal in the trickling filter. 15. Wastewater samples are collected by a time composite sampling device which collects a 100-m1 sample every one-half hour from the 13,000 gallon discharge tank. 16. Solids collected on the screens are placed in containers. Solids which are collected in the lamella separator and DAF clarifier are dewatered in a centrifuge. All solids are contained in bins, transported off-site, and used for animal feed or landfilled. 17. RO reject water normally is directed to the 13,000 gallon discharge tank but can be directed to the trickling filter. This is done occasionally if the wastewater discharged to the trickling filter becomes too acidic due to an overload of sugar and the resulting organic acids. The Discharger can raise or lower the pH during the treatment process,but has rarely found it necessary to lower the pH. 18. After treatment, the wastewater is piped to the land application area which consists of 17.6 acres divided into 16 subbasins consisting of approximately one acre each. The disposal area has been laser leveled and is surrounded by a berm approximately two feet high. The location of the 17.6 acre land application area is presented in Attachment B,which is attached hereto and made part of this Order by reference. 19. The Discharger has recently added a pump station along the land application pipeline to allow reclamation of wastewater to 9.2 acres of landscaped area surrounding the existing facility and the south warehouse. The wastewater will be sprinkler applied to landscaped areas. The location of the landscaped area is presented in Attachment B. 20. In the year 2000, wastewater discharge to the land application area ranged from 80,000 to 171,000 gallons per day(gpd). The Discharger also trucked approximately 8,000 gallons per week of wastewater to the City of Lathrop Crossroads treatment facility at the request of the City. This discharge has now been stopped since the City no longer needs the wastewater to assist in the denitrification process. 21. The City of Lathrop and the City of Manteca have permitted CNP to discharge up to 150,000 gpd of process wastewater and domestic wastewater to the Manteca wastewater treatment plant on an interim basis. CNP typically discharges approximately 50,000 gpd to the municipal system. Additional wastewater disposal is available at higher disposal fees. 22. The flow to the municipal system utilizes capacity that is allocated to the City of Lathrop,but not yet used. CNP has purchased a capacity of 200,160 gpd in the expansion of the Manteca wastewater treatment plant that is currently in progress and is scheduled to become available in 2003. Additional interim unused capacity allocated to the City of Lathrop may be temporarily available at the City of Manteca plant.