15 FOG Receiving Start Up
Marrborg Industries delivers FOG to the WWTP on a daily basis. Typical deliveries involve 1 or 2 trucks, containing a total volume of 2500 – 3000 gallons of FOG. Marrborg calls the WWTP in advance and provides an estimate of the volume of that day’s delivery.
An Operator must be present while FOG offloading takes place, however, it is the driver's reponsibility to connect the truck's equipment to the FOG conveyance system.
FOG is not water soluble and tends to separate out from the liquid solution. In addition, cooled FOG can congeal and can mat the surface of tanks, digesters, pipe interiors and other surfaces. Large amounts of FOG in WWTP pipe systems, reduce their capacity and create more frequent maintenance. Typical sources of FOG are restaurants and other food facilities.
The El Estero WWTP FOG Receiving System separates the FOG from the treatment process.
FOG: Fats, oils and grease.
Watch for open tanks and high elevations. If working on or near equipment, watch for rotating parts. Watch for tripping hazards.
- FOG Receiving Tank must have capacity before accepting an incoming load. Notify Marrborg immediately if the tank has insufficient capacity so the delivery can be postponed.
- If any spill occurs in the secondary containment tray, drag the tray to the nearest drain and hose out to the drainline. The FOG Receiving Facility does not have a dedicated drain at that location.
Operator I, knowledge of digestion process and equipment controls.
- Secondary containment tray (to be used below the truck/FOG receiving connection point)
- Record activity to log book.
Marrborg Industries typically delivers FOG to the WWTP on Tuesdays and Thursdays, however, plant staff will accept deliveries on other days to accommodate Marborg’s needs. Typical deliveries involve 1 or 2 trucks, containing a total volume of 2500 – 3000 gallons of FOG.
Pre-FOG Delivery
1. Verify FOG Receiving Capacity:
a. Check the current volume of the FOG Receiving Tank {tag no.1508TNK5691} at the SCADA screen.
b. Compare the current volume and remaining capacity with the estimated delivery volume. Determine if there is enough capacity in the FOG Receiving Tank to accommodate the delivery. Pump down the tank if required to accommodate the delivery.
FOG Delivery
1. Driver’s Responsibilities:
a. Upon arrival at the FOG Receiving Station, the Marrborg driver pushes the “doorbell” button at the local FOG control panel. A signal is sent to SCADA, notifying the operator of the FOG delivery. .
b. An operator must be present while FOG offloading takes place at the FOG Receiving containment area.
c. The FOG delivery driver is responsible for connecting the truck’s equipment to the FOG conveyance piping {tag no. 1508CNVS5692}.
2. Record Data:
a. Before any offload occurs, the Operator shall observe and record the tank depth as displayed at the Local Control Panel.
b. Before any offload occurs, the Operator shall observe and record the tank volume as displayed at the Totalizer.
3. Secondary Containment:
a. Place the plastic secondary containment tray below the truck/FOG receiving connection point.
4. FOG Offload.
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a. Open the isolation valve {tag no. 1508VLV5691}.
b. The Marrborg driver will offload the FOG to the FOG Receiving Tank {tag no. 1508TNK5691}.
c. A flow sensor and transmitter {tag nos. 1508FE5321 and 1508FIT5321} record and transmit the flow of FOG as it is offloaded to the FOG Receiving Tank.
d. The PLC will signal an alarm {tag no. 1508LAHH5551} if the volume in the FOG Receiving Tank reaches the high level switch {tag no. 1508LSH5541}.
5. FOG Pumping.
a. The FOG Feed Pumps {tag nos. 1508PMP5300, 1508PMP5400} are controlled by the PLC and operate automatically. The operators input a volume (or depth) to be pumped from the FOG tank to the PLC. The PLC will determine the pumping rate and frequency.
b. The FOG Mixing Pumps {tag nos. 1508PMP5100, 1508PMP5200} are controlled by the PLC and operate automatically.
Post FOG Delivery:
1. Record Data:
a. Operator observes and records the new tank volume from the Totalizer screen after the FOG delivery has been offloaded to the Receiving Tank.
2. Secondary Containment:
a. The Marborg driver disconnects the truck hose from the FOG Receiving connection.
b. If any spill occurs in the secondary containment tray, drag the tray to the nearest drain and hose out to the drainline. The FOG Receiving Facility does not have a dedicated drain at that location.
c. Replace the secondary containment tray to its original position at the FOG Receiving Facility.
3. Rock Trap:
a. Operator shall wear gloves for this task.
b. Unfasten and remove the lid to the rock trap {tag no. 1508TRP5691}.
c. Check for rocks and debris in the trap.
d. If found, dump debris from the rock trap to a plastic bag. Dispose of plastic bag accordingly.
e. Replace rock trap lid and lock into place.
To feed the FOG waste to the digesters:
- Initiate the pumping cycle in SCADA to feed the FOG waste to the digester that is not being fed sludge from the plant.
- Make sure the digester feed pumps are off.
- Adjust the digester feed pumps stop level set point by 0.8 feet.
- Put feed pump in Hand.
- Pumps will shut off automatically even though pumps are in Hand.
- Update log book.
- Update maintenance records (if applicable).
- Report any maintenance or attention that is required.
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