No person shall construct or install any underground storage facility tank system or make any substantial modification or repair thereto, except in accordance with the following requirements:
(A) Monitoring capability. All underground storage facilities and tank systems must be equipped with monitoring systems and be monitored in accordance with the following requirements:
(1) All underground storage facilities, including tanks and tank systems, intended to be used or used for the storage of hazardous materials shall be designed, constructed and operated with a continuous monitoring system and an instant alert capable of detecting that the hazardous material stored in the primary containment has entered the secondary containment. If water could intrude into the secondary containment, a means of continuous electronic monitoring for water intrusion shall also be provided unless water within the secondary containment is part of the system design. The monitoring system shall be capable of differentiating between water and the hazardous material contained;
(2) An automatic telephone dialer or an audio-visual alarm system designed to be activated by a release from the primary containment shall be installed with alarm terminals at the underground tank site and at the Sunset Valley City Hall;
(3) A minimum of three observation wells constructed of non-conductive material, with a minimum diameter of four inches, shall be installed within each underground storage tank excavation. The wells shall extend to a depth of a least 12 inches below the level of the bottom of the tank(s) and shall be lined with electronic hydrocarbon vapor sensors or be perforated in a manner so as to be capable of detecting the presence of floating contaminants over the entire length of the wells. At least one additional observation well shall be installed in a location outside of and downdip of each storage tank excavation, and shall be at least four feet deeper than the pit liner;
(4) Manways shall surround all turbine pumps and fill tubes to allow inspection of fittings and to facilitate the containment of leaks or spills. All manways shall be sealed to the storage tank in order to contain any leaks or spills. Electronic sensors shall be located in the manways to monitor for the presence of hydrocarbons and alert the operator of possible problems;
(5) Electronic hydrocarbon sensors, located at several locations along the delivery piping, shall be installed to monitor the interstitial space and to alert the operator of possible problems;
(6) Monitoring devices shall be installed between double-walled delivery piping and the synthetic liner to monitor releases or leakage from the piping;
(7) Monitoring systems and/or observation wells, and all component parts thereof, shall be installed in accordance with any applicable codes and shall be operated and maintained in good working order;
(8) Testing of monitoring equipment and emergency shut-off valves shall be conducted by a certified technician at least once a year; the certification record shall be maintained at the facility at all times and a copy thereof provided the city within seven days of the annual certification.
(9) The permit holder shall conduct such self-monitoring inspections and tests as the city may require and shall file reports attesting to the date and time of each such inspection or test. These reports shall also contain a description of the inspection or test performed, the results of each inspection or test and the printed name and title and the initials of the inspector. Failure to comply with the city's request pursuant to this section shall constitute a violation of this chapter.
(B) Containment requirements. Primary, secondary and tertiary levels of containment shall be required for all underground storage tank systems. Such systems shall meet the following specifications:
(1) All tanks or containers shall be highly resistant to the hazardous materials they are designed to contain and shall also be resistant to the particular environment in which they are stored and any physical handling they may be subject to for their projected design life;
(2) All tanks or containers must bear labels certifying adherence to appropriate specified construction methods and factory pressure testing for tank integrity, and must be installed by a licensed underground storage tank installer according to the manufacturer's specifications;
(3) All primary containment shall be product-tight;
(4) All secondary containment shall be external to and separate from the primary containment and all tertiary containment shall be external to and separate from the secondary containment. All secondary and tertiary 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 any discharged hazardous material and so as to be capable of containing any hazardous material discharged from a primary container and preventing its release into the environment for a period of time longer than the maximum anticipated time sufficient to allow recovery of the discharged hazardous material;
(5) In the case of an underground storage tank with one primary container, the secondary and tertiary containment shall be large enough to contain at least 110% of the volume of the primary container;
(6) In the case of an underground storage tank with multiple primary containers, the secondary and tertiary containment shall be large enough to contain 110% of the volume of the largest primary container placed in it, or 50% of the aggregate internal volume of all primary containers in the storage tank, whichever is greater;
(7) Tertiary containment shall be provided by a liner system approved by the city to meet the following standards:
(a) The liner must be capable of preventing migration of any stored or leaked materials from the tank hold for a period of at least 50 years;
(b) The liner must be of sufficient strength and thickness to prevent failure, including from static head and external hydrogeologic forces;
(c) The liner must be constructed of material that will maintain its strength, impermeability and thickness even when in direct and long-term contact with the stored or leaked materials;
(d) The liner must be placed on a foundation capable of supporting the liner and preventing failure due to settlement, compression or uplift;
(e) The liner must be installed to the surface of the tank hold;
(f) The liner must be installed according to manufacturer's specifications, and installation, field-seaming, and field-repair of any liner must be performed only by qualified personnel properly trained and certified by the liner manufacturer;
(g) The liner must be protected from puncture, abrasion, or other damage during placement, and a protective layer of material is required where the presence of any material could puncture or damage the liner;
(h) After installation, but before placing the tanks, the liner shall be properly tested in accordance with the manufacturer's specifications.
(8) All tank excavation pits shall be equipped with liners which come at least three feet up the sidewalls of the excavation, if the excavation is in clay, and come at least to the top of the storage tanks if the excavation is in limestone. The liners shall be of such design and material so as to be impervious to and non-reactive with hydrocarbons and may be a custom-fitted polyliner;
(9) An underground storage tank with a double-walled primary container with a complete double shell shall be deemed to meet the primary and secondary containment requirements set forth in this section if the outer shell is constructed primarily of non-earthen materials, including but not limited to concrete, steel and fiberglass, which provide structural support, and an electronic leak detection system is located in the interstitial space (between the shells) which is continuously monitoring the space for the entry of hazardous substances from the inner container to the space and for the detection of water intrusion into the space from the outer shell;
(10) Appropriately sized catch pans shall be installed under all delivery pumps;
(11) All underground delivery piping must be of double-walled fiberglass construction which provides secondary containment of any fuel releases from the primary piping, and shall be surrounded by synthetic lining; and
(12) In the case of readily visible portions of underground storage tank piping, no secondary or tertiary containment is required, provided that it is being regularly and periodically visually inspected in an approved manner.
(C) Overfill protection and transfer spill prevention. An approved means of overfill protection and transfer spill prevention shall be required for all underground storage facilities. At a minimum:
(1) An overfill prevention device shall be connected to the vent line to restrict flow into an underground storage tank when the tank is 90% full;
(2) An overfill containment device shall surround the fill tube to collect any residual drainage from the delivery hoses;
(3) A pressure loss indicator shall be installed on turbine pumps to automatically shut the pumps down should a loss in pressure occur;
(4) A line leak detector shall be installed on submersible pumps to automatically shut the pumps down in the event of a leak or release;
(5) The piping trench shall slope backwards to the line tank pit at an angle sufficient to insure that any released or escaped hazardous materials flow towards the tank pit;
(6) Collection pans shall be installed beneath each dispenser to collect any small leaks or spills occurring during maintenance of the dispensers; and
(7) Underpump emergency valves shall be installed on each fuel delivery line beneath the dispensers to automatically shut off fuel flow in the event of damage to the dispensers from collision, fire or any other cause.
(D) Drainage and sumpage removal. Drainage of precipitation and sumpage from within an underground storage tank shall be controlled and disposed of in accordance with all applicable state, federal and local laws and regulations for the containment and disposal of hazardous liquids so as to prevent hazardous materials from being released into the environment in an unapproved manner. No drainage or sumpage removal system shall be approved unless the said system meets the following minimum requirements:
(1) Site surface drainage shall be designed so that runoff from the areas around the pump islands and storage tanks is collected and routed to a water quality control.
(2) The water quality control shall be designed to treat the first one-half inch of runoff from the collection area to achieve at least the following removal efficiencies: 95% TSS removal and 99% removal of oil and grease or chemical oxygen demand.
(3) The water quality control shall be designed to bypass water to prevent scouring of the collecting material.
(4) The water quality control, including any gaskets, shall be constructed of materials that will not degrade during long-term exposure to the stored materials.
(5) The water quality control shall be installed according to applicable manufacturer's recommendations.
(6) The water quality control shall include an electronic hydrocarbon sensor to alert the operator of the need to remove hydrocarbons from the separator.
(E) Flammable liquids. In addition to any other requirements of this chapter, no person shall construct or install any new underground storage tank intended for the storage of flammable liquid or make any substantial repair or addition to or modification of an existing underground storage tank system containing flammable liquid, unless and until said tank system is designed and constructed to meet, at a minimum, the standards provided by the State of Texas "Rules for the Safe Storage, Handling, and Use of Flammable Liquids at Retail Service Stations" (28 TAC 27.601-27.620).