CUP #2025-005 – Wastewater Treatment Facility

The applicant is requesting a Conditional Use Permit on APN(s): 029-280-054; 029-290-011;014, located on the northwest and northeast corner of Avenue 18 and Road 24 (23865 Avenue 18), Madera, to allow for the construction of two wastewater treatment facultative ponds, one storage pond, one stormwater basin, one mechanical building and three worm beds to process and reclaim wastewater from corn washing operations. The reclaimed water will be used for irrigation purposes. The parcels are approximately 409 total acres and rectangle in shape. Parcel 029-280-054 is separated from parcels 029-290-011 and 029-290-014 by Road 24. Parcels 029-290-011 and 029-290-014 are connected near the intersection of Road 24 and Avenue 18. Currently, the parcels are being used for agricultural uses related to Azteca Milling operations. Operations on the parcel are focused on processing corn and washing corn. The topography of the parcels are relatively low elevations and flat, consistent with the Central Valley floor’s characteristics. The project proponent proposes to implement two types of wastewater treatment – a facultative pond (combination of anaerobic and aerobic treatment) and BioFiltro BIDA biofilter worm system. Each type of treatment will have the capacity to completely treat the wastewater prior to storage. Azteca also requested that the two types also work in parallel or in series. The existing pipe delivery system from the facility to the current field area will be altered slightly. Stormwater runoff from the main buildings and plant area, currently comingled with wastewater, will generally be routed separately to the treatment area and sent directly to the storage pond, bypassing treatment systems. Azteca plans to improve solids separation with some additional equipment before sending the wastewater out to the treatment area in the existing pipeline. Facultative Pond 1 will receive the wastewater from the facility. The anaerobic and aerobic treatment will occur in both ponds. Water will gravity flow out of Facultative Pond 1 into Facultative Pond 2 where it will be treated further. After Facultative Pond 2, water will gravity flow out and into the storage pond. Gravity flow pond to pond ensures that if there is a pump issue or power outage, water will safely arrive at the storage pond. Due to higher water temperatures from the facility that the worms cannot take, water for the worm beds will be drawn off at the head end of Facultative Pond 1. This water will be pumped to an equalization tank. This pump will be variable flow and by that can operate at 100% flow (independent system) or partial flow to operate as a parallel system. If water is not pumped to the worm beds, then the facultative ponds will be operating independently. Post worm bed water treatment, water that is not pumped to the facultative ponds for further treatment (for series operation) will gravity flow to the storage pond providing that safety mechanism. Following water treatment, the water will be stored in a pond until it is needed for crop irrigation. The 20.0 MG (million gallons) is sized for storing the water generated in the non­irrigation periods of the Nutrient Management Plan plus a 100-year rainfall year collecting rainwater from the facility, treatment area, and the ponds directly. The treated water will be used to irrigate two fields on either side of the treatment area. East of Road 24, 40 acres of almonds will be removed, and another field will be created to irrigate forage crops in that area. A supply pipe from the storage pond will need to be routed underneath Road 24. In the future, treated water irrigation may continue into the remainder of the crop land (APNs 029-290-011 and -014). To accomplish this a remote storage pond may be needed and is shown in the site plan. In this potential scenario, water will be pumped from the main storage pond to the orchard pond to stage the water for the orchard irrigation system. Approximately everyone (1) to three (3) years, the wood chips will be replaced on a worm bed, typically spring or summer. Approximately 35 to 70 trucks will stage the new chips in the storage area to the east of the beds. Old chips will be moved to the side of a bed in a windrow, new chips will be placed on the bed, the worms will be transferred back to the bed, and the old chips will be allowed to dry before hauling away. Approximately 20 to 40 trucks will haul away the used chips. Alternatively, wood chips could be applied as a soil amendment to the land application area. The maintenance building will provide space for the blowers needed for the facultative ponds, a room for electrical panels and controls, a shop area, and an office with a restroom.