Secondary Containment

Section 255 Section 255.80  Secondary Containment a)         All agrichemical non-mobile storage containers for liquid pesticides and liquid fertilizer shall be located within a secondary containment structure. b)         Secondary containment structures and systems shall provide the following capacity: 1)         When not protected from receiving precipitation, the containment shall have a minimum containment volume of a 6-inch rain storm (a 25 year, 24 hour rain), plus the capacity of the largest tank, and the volume displaced by the bases of the other tanks located within the secondary containment structure. 2)         When protected from receiving precipitation, the containment shall have a minimum containment volume of 100% of the capacity of the largest tank, plus the volume displaced by the bases of the other tanks located within the secondary containment structure. c)         Structural materials and integrity shall provide secondary containment that meets or exceeds the requirement of this Section.  Materials shall be compatible with the agrichemical to be contained. 1)         General requirements include: A)        Clay, natural soil clay mixtures or clay/bentonite mixtures shall not be used to contain any bulk pesticide. B)        Secondary containment for liquid agrichemicals storage at facility sites should provide for separation between bulk pesticides and bulk fertilizer to the extent that a common wall or curbing between the fertilizer area and the pesticide area shall provide for the interception and recovery including clean up of pesticide spills while the entire secondary containment area shall meet or exceed the total capacity requirement specified in this Section. C)        The secondary containment structure shall be constructed to a water permeability rate of not greater than 1 x 10 -6 centimeters per second and maintained so that liquid movement through the walls and base does not exceed a rate of 1 x 10 -5 centimeters per second permeability rate.  The secondary containment structure shall be designed and maintained to withstand a full hydrostatic head of any contained liquid.  The containment area shall not be equipped with a permanent pump unless the pump has only a manual mode of operation. D)        The secondary containment structure shall not have a discharge outlet or gravity drain through the wall or floor. E)        Synthetic materials or liners may be used with secondary containment structures provided they are compatible with agrichemicals being contained and it is installed according to manufacturer's written direction and repaired and maintained according to manufacturer's recommendations.  These directions and recommendations shall become records maintained at the facility site. 2)         Walls:  The walls of secondary containment structures shall meet each of the following criteria: A)        Walls shall be constructed of materials, including but not limited to, steel, reinforced concrete, solid masonry, or compatible synthetic materials or synthetic liners as authorized in this Section. B)        No piping shall be installed through the wall except for interconnections between multiple secondary containment structures authorized in this Section. C)        Multiple basins connected to provide the containment capacity as set forth in this Section shall be connected in a manner that assures an unrestricted transfer of discharged liquid between basins. D)        Earthen walls used for secondary containment of fertilizer shall be protected against erosion (e.g., sodding and seeding).  Side slopes shall not exceed a 3 to 1 ratio of horizontal to vertical.  The top width of earthen walls shall not be less than 2½ feet. E)        Provisions shall be made for safe and emergency access and exit to and from the secondary containment structures. 3)         Floor:  The base of a secondary containment structure shall be lined with materials, including but not limited to, reinforced concrete, steel, or compatible synthetic liner or synthetic materials as authorized in this Section, and the floor shall meet each of the following criteria: A)        Floors shall be constructed to allow the safe and expeditious removal of precipitation water and any spilled liquid in a manner that does not disrupt the ability of the containment structure to prevent the movement of liquid as required in this Section (e.g., sloped to a collection sump well). B)        Liners used for secondary containment of fertilizer may be constructed of suitable soil or of soil treated with bentonite clay or other comparable material, with a minimum depth of 12 inches provided the other floor requirements as stated in this Section are met.  The liner shall be covered by a soil or smooth aggregate layer not less than 6 inches thick and shall be maintained to prevent cracking or puncture. 4)         Prefabricated facilities:  A prefabricated secondary containment structure shall be composed of a rigid prefabricated basin having both a base and walls constructed of steel, reinforced concrete or synthetic liner or synthetic materials which are resistant to corrosion, puncture, or cracking.  A written confirmation of compatibility and a written estimate of life expectancy from the basin manufacturer shall be kept on file at the facility.  Multiple basins connected to provide the capacity required in this Section shall be connected in a manner which assures an unrestricted transfer of discharged liquid between basins. 5)         Drainage and basin facility:  A drainage and basin facility diverts uncontaminated storm water drainage and provides secondary containment in accordance with this Section.  The curb, base and drainage path shall be at least 12 inches thick and shall be constructed in lifts not to exceed 6 inches in thickness.  Persons wishing to use a drainage and basin facility should consider the overall facility plan, topography, subsoil type, water table location, and surface water drainage patterns. d)         Facilities with mini-bulk containers filled and warehoused for product distribution shall: 1)         Provide warehousing area secondary containment structures or systems equal in volume to the largest container stored; or 2)         Provide a current immediate response action plan for leakage or spillage and maintain necessary supplies and equipment to effect containment recovery and residue clean-up, in order to be in compliance with secondary containment provisions of this Part.