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i I~ I I I 4.3.1.2 Spill Prevention, Control, and Countermeasures for Process Reagents VLF -Dilute cyanide leach solution (typically 0.01 % to 0.02% or 100 - 200 ppm) is directed to and from the VLF through an HDPFJsteel piping system. Pregnant lines are steel and barren lines are steel/HDPE. The pipelines are also equipped with an automatic shut-off, triggered by flow or pressure differentials. In the unlikely event that solution drain or spray off liner, spill response procedures described in section 5.2.3 of this ERP/SPCC should be followed expeditiously. Pipes, drip lines, and conveyances that direct cyanide solution to and from the VLF are generally installed 15 feet between the conveyance and the edge of the liner. CC&V may also affix pieces of synthetic liner on the side of flanges and valves facing the edge of the liner to reduce the chance of off-pad spraying should a leak develop. Sodium Cyanide Briquettes -Solid briquettes of NaCN contained in vendor-provided Flo-Bins are stored west of the ADR Plant in a lined, fenced area that drains north to the adjacent VLF. These Flo- Binsare transported by forklift around the outside of the building and emptied into tanks located inside the ADR. During ADR operations, releases from the stored NaCN flow bins would remain on the VLF liner and migrate north toward the main liner system as the cyanide dissolved. Flo-Bins are returned to the vendor. If the vendor requires them to be rinsed prior to returning, Flo-Bins may be triple rinsed under the supervision of experienced Process Personnel with residue going to the containment provided by the VLF. Bulk Cyanide Delivery Most of the cyanide briquettes will be delivered to the Plant in bulk and the transporter will park on containment while the bulk material is dissolved and is pumped to two 20,000-gallon holding tanks. Sodium Hydroxide - NaOH liquid is stored directly west of the ADR Plant in a 20,000-gallon tank within concrete secondary containment and within the tertiary containment of the lined area of the VLF. The concrete containment sump is equipped with afloat-activated pump that would return fluid to the plant circuit in the event of a release. A release outside the concrete containment would remain on the VLF liner and migrate north toward the main liner system. Hydrochloric Acid - HCI liquid is stored directly west of the ADR Plant in an 8,200-gallon, double- walled tank within concrete containment and within the lined area. Releases outside the tank containment would flow north, completely contained within the liner. Antiscalant - Antiscalant liquid is not a hazardous chemical. It is stored outside the ADR Plant in a 4,000-gallon capacity single-walled, foam-insulated tank on the concrete floor. The ADR Plant is located on liner that drains to the VLF. Antiscalant is also stored within the VLF in insulated tanks. . Release of Antiscalant should be controlled, even though the residue is not hazardous. Complete removal of impacted soils is not required. Contaminated soils may be placed on the VLF if desired. Hvdrooen Peroxide - HZOz liquid is stored in totes in the Ironclad Warehouse facility. In the event of a ' transfer of VLF pond water to the external storage pond, H2O2 would be transported from the warehouse to the eMemal storage pond and used to oxidize cyanide. HZOZ releases are a potential safety hazard due to the oxidizing potential of this chemical. However, the fluid will rapidly react with ' and will be attenuated by the soil. Any additional clean-up should not be required. Secondary and Tertiary Containment at the ADR Facility -Several redundant containment features exist at the ADR including: (1) liner extends under the building itself forming a continuous barrier to ' guard against spills reaching the ground water; (2) the ADR building has a concrete floor and curbing that provides secondary containment for spills from reagent tanks; and (3) same of the tanks are double walled construction. 29