Laserfiche WebLink
2.2.1.2 Tank Farm <br />The plant tank farm consists of a piping manifold and two tanks, one of which contains pregnant <br />liquor and one of which contains barren liquor (Figure 2). This is the location where the <br />pregnant liquor is both stored and enters the plant and the barren liquor is both stored and exits <br />the plant. In addition, this is the location whereby makeup water from the 90 -1 or WSW -2 water <br />supply wells enters the plant. Owing to the high TDS, sodium, and chloride constituents <br />contained within the pregnant and barren liquors, a water spill from either of the tanks or from <br />the piping itself could contribute non - hazardous pollutants to stormwater discharge. <br />A concrete wall encloses the pregnant and barren liquor tanks, which would prevent the <br />spreading of a fluid in the event of a spill. In addition, both tanks sit on concrete containments <br />which would allow for minor leaks from the tanks to be contained. The concrete enclosure <br />drains to the NSI process pond. The tanks and the piping are appropriately labeled with placards <br />designating what each contain and are routinely inspected once a month for leaks or cracks. <br />2.2.1.3 Storage Silo /Loadout Area <br />The storage silo contains the solid sodium bicarbonate product after it has been run through the <br />process line and transferred to the silo via conveyor belts (Figure 2). In the storage silo, the <br />product is stored in a pile and loaded unpackaged onto semi - trucks in the loadout area <br />immediately adjoining the silo. The higher grade product is bagged, palletized, and loaded onto <br />trucks in the loadout area directly attached to the plant. Sodium bicarbonate is a non - hazardous <br />substance, but is highly water soluble and would be easily incorporated as a constituent in <br />stormwater discharge. Because the crystallized sodium bicarbonate is very fine - grained, there is <br />an abundance of sodium bicarbonate dust in and around the silo and loadout area. In addition, <br />there is the potential for discharge from motor vehicle wastes from the semi - trucks that load the <br />pallets of product in the silo and loadout area. <br />In order to reduce the amount of sodium bicarbonate dust that is emitted from the silo, the doors <br />of the silo are kept closed at all times except in cases of a potential safety hazard. In addition, <br />dust suppression and collection equipment is included on the conveyor transfer points and in the <br />dome storage building. Bagged and palletized product is shrink- wrapped to contain any bags of <br />product that may potentially have a puncture and therefore reduce the possibility of sodium <br />bicarbonate dust escaping. Trucks are loaded with product in the bulk loadout building. The <br />area containing the storage silo and bulk loadout building has a drain to the process pond. The <br />sodium bicarbonate dust that accumulates in this area is periodically washed down to the process <br />pond and the area is cleaned. <br />2.2.1.4 Product Transport <br />As of 2011, the NSI plant produces approximately 125,000 tons of sodium bicarbonate per year, <br />with expected expansion to 250,000 tons of sodium bicarbonate per year from a gradual ramp up <br />Daub & Associates, Inc. NSI 2011 SWMP <br />Page 5 <br />