(1) All operational area activities shall take place on or within operational area containment: Provided, That during the unloading or loading of railcars, marine vessels, or manned trucks when product is unloaded from direct shipments from manufacturers, individual basins or portable storage containers shall be used to recover spillage and leakage from transfer connections and pumps.

(2) Operational area containment shall be designed and constructed to contain fertilizers, rinsates, washwater and other materials spilled or deposited during mixing, loading, unloading, draining, rinsing and washing activities.

(3) The walls and floor of operational area containment shall be constructed of steel, poured reinforced concrete, precast concrete modules, solid masonry, or other materials or combination of materials that:

(a) Are designed to withstand a full hydrostatic head of any discharged liquid;

(b) Have sufficient thickness and chemical resistance to contain a release until it is recovered;

(c) Are constructed and maintained to a permeability standard of 1x10-6 cm/sec as determined by ASTM test method D-5084 Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter or other test method approved by the department.

(4) If synthetic materials are used in construction they shall be chemically compatible with the products handled at the site. A written confirmation of compatibility from the manufacturer shall be kept on file at the site or the nearest location from which the site is administered.

(5) Operational area containment shall be constructed to withstand the weight of any vehicles or storage containers which will be on it.

(6) Operational area containment shall be constructed with sufficient surface area, using curbs or other means, to prevent any discharge from leaving the containment area. The operational area containment shall have a capacity of at least fifteen hundred gallons. If no storage container or mobile storage container used at the operational area containment to transfer liquid bulk fertilizers has a capacity of more than one thousand gallons, the operational area containment shall be of adequate size and design to contain one hundred twenty-five percent the capacity of the largest storage container, or mobile storage container used.

(7) Operational area containment shall slope to one or more liquid tight collection points or sumps that allows spilled or deposited materials to be easily recovered.

[(8)] An above ground storage container may be used in conjunction with the operational area containment to meet the capacity requirement. If an above ground storage container is used to meet the capacity requirement, the storage container shall be located within secondary containment. The storage container shall be clearly and conspicuously labeled "fertilizer rinsate."

(9) Any pump used for recovering material from the operational area containment shall be manually activated.

(10) The operational area containment shall not have a discharge outlet or valve. Discharge outlets or valves on existing operational areas shall be sealed. Operational area containments may be interconnected.