Precious Metals Recovery LLC RCRA Permit Application Dry Hills ...

22.5 Description of Secondary Containment – 40 CFR 264.175 & 270.15(a)
The containment system for areas where liquid hazardous waste is designated to be stored will be
designed to have sufficient capacity to contain 10% of the total volume of liquid stored or 100%
of the volume of the largest container, whichever is greater. The secondary containment system
at the proposed TSF will consist of spill trays, bunded areas, sumps, and trenches.
Secondary containment for elemental mercury will be provided by spill trays. Each spill tray is
designed to provide secondary containment for a group of eight pigs. The spill tray as depicted in
Appendix 1-A, is designed to contain 2,200 lbs of elemental mercury, which is the volume of
one pig, and is greater than 10% of the combined volume of eight pigs. A sample calculation is
presented as Appendix 22-B.
An additional layer of secondary containment will be provided in the elemental storage area by
the building envelope, which consists of a combination of epoxy coated concrete walls, floors,
curbs, and trenches. The epoxy enamel coating on these surfaces is designed to prevent
absorption of mercury. See Drainage Arrangement H340940-0000-50-015-0008 provided in
Appendix 1-A. Containment volume calculations are included in Appendix 22-B.
The largest type of container that is expected to be stored in the plant spaces will be the drums
that contain calomel, which each have a maximum volume of 55 gallons; therefore, the
secondary containment volume in the plant spaces is designed to contain 10% of the total
expected volume of elemental mercury and calomel that can be stored. At maximum capacity,
the total volume of these combined liquids is estimated to be 32,300 gallons. The building
envelope of the proposed TSF (i.e., the volume of the bunded area), is designed to provide a
secondary containment volume of 95,750 gallons, which is significantly larger than 3,230
gallons (i.e., 10% of the estimated total volume of liquids to be stored in this area).
22.6 Description of Containment System – 40 CFR 270.15 & 264.175(b)(3)
Spent activated carbon containers and calomel containers will be stored in a common storage
area. Containers that do not contain free liquids need not be considered in this calculation. For
the purpose of calculating necessary containment volume, containers of spent activated carbon
will not be included in the inventory of containers with free liquids.
22.6.1 Floor Design – 40 CFR 264.175(b)(1)
The floor in the container storage areas is designed to be free of cracks or gaps and will be
sufficiently impervious to contain leaks or spills until the collected material is detected and
removed. The floor will be inspected in accordance with the Inspection Plan (see Appendix 4-A).
Consideration of precipitation and run-on volumes for the storage area will not be applicable for
the proposed TSF, because the storage areas will be located inside the proposed TSF Building.
No precipitation is expected to enter or collect in the container storage areas.
PMR RCRA Permit Application, Dry Hills Facility Page 111
JBR Environmental Consultants, Inc. | HATCH March 2013