17.12.020   New storage facilities.
   (a)   No person shall construct or install any new storage facility until a permit or approval has been issued pursuant to this title.
   (b)   Monitoring Capability. All new storage facilities intended for the storage of hazardous materials which are liquids or solids at standard temperature and pressure (STP) shall be designed and constructed with a monitoring system capable of detecting that the hazardous material stored in the primary containment has entered the secondary containment.
   Visual inspection of the primary containment is the preferred method; however, other means of monitoring may be required by the fire chief. Where secondary containment may be subject to the intrusion of water, a means of monitoring for such water shall be provided.
   Whenever monitoring devices are provided, they shall, where applicable, be connected to attention-getting visual and/or audible alarms.
   (c)   Containment Requirements. Primary and secondary levels of containment shall be required for all new storage facilities intended for the storage of hazardous materials which are liquids or solids at standard temperature and pressure (STP), unless specifically herein exempted by the fire chief.
   (1)   All primary containment shall be product-tight.
   (2)   Secondary Containment:
   (A)   All secondary containment shall be constructed of materials of sufficient thickness, density, and composition so as not to be structurally weakened as a result of contact with the discharged hazardous materials and so as to be capable of containing hazardous materials discharged from a primary container for a period of time equal to or longer than the maximum anticipated time sufficient to allow recovery of the discharged hazardous material.
   (B)   In the case of an installation with one primary container, the secondary containment shall be large enough to contain at least one hundred ten percent of the volume of the primary container. In addition, the secondary containment shall contain no outlet that would allow drainage to either the sanitary sewer system or the storm sewer system, as those terms are defined in Chapter 16.09 of the Palo Alto Municipal Code.
   (C)   In the case of a storage facility with multiple primary containers, the secondary containment shall be large enough to contain one hundred fifty percent of the volume of the largest primary container placed in it, or ten percent of the aggregate internal volume of all primary containers in the storage facility, whichever is greater.
   (D)   If the storage facility is open to rainfall, then the secondary containment must be able to additionally accommodate the volume of a twenty-four-hour rainfall as determined by a one-hundred-year storm history. Rainwater shall be removed from the containment area. Removal shall be done by means of approved systems that cannot be left open when unattended.
   (E)   Secondary containment shall remain free of product from normal use and shall assist in monitoring efforts. Interior containment shall remain free of product and water unless water is a part of the monitoring system. Exterior containment shall remain free of product and water except for rainfall within twenty-four hours or water which aids in approved monitoring program.
   (3)   Laminated, coated, or clad materials shall be considered single walled and shall not be construed to fulfill the requirements of both primary and secondary containment.
(Ord. 4066 § 2, 1992: Ord. 4002 § 1 (part), 1990: Ord. 3496 §§ 4, 9, 1983: Ord. 3435 § 1 (part), 1983)