§ 27-308. Release detection standards, methods, and performance standards.
(a)
Release Detection Standards.
(1)
General.
a.
Storage tank systems shall have a method, or combination of methods, of release detection that:
1.
Can detect a new release from any portion of the storage tank system;
2.
Is installed, calibrated, operated and maintained in accordance with the manufacturer's instructions, including routine maintenance and service checks for operability to ensure that the device is functioning as designed; and
3.
Meets the applicable performance standards in section 27-308(c). All manufacturer's instructions, and the performance claims and their manner of determination described in writing by the equipment manufacturer or installer shall be retained for as long as the storage tank system is used.
b.
A release detection response level shall be described in writing for each method or combination of methods of release detection used for a storage tank system.
c.
A release detection method shall be established and provided for all storage tank systems upon installation.
d.
Except as otherwise specified in section 27-308, the release detection method or combination of methods used at a facility shall be performed at least once a month, but not exceeding thirty-five (35) days, to determine if a release from the storage tank system has occurred.
e.
At least once a month, but not exceeding thirty-five (35) days, any storage tank and component of a storage tank that can be inspected visually shall be visually inspected in accordance with section 27-308(c)(2)e. A visual inspection is not required for any system component that has a continuous or monthly electronic release detection sensor. Continuous electronic leak detection devices shall be inspected for proper operation on a monthly basis. Inspection may consist of visual observation or remote verification of proper operation.
f.
A site suitability determination shall be performed for UST systems by December 31, 1998, and January 1, 2000, for AST systems, in accordance with section 27-308(c)(2)a. through d., for storage tank systems using groundwater or vapor monitoring wells for release detection. If the site suitability determination indicates that on-site conditions are unsuitable for external monitoring, another method of release detection must be used.
g.
Vapor monitoring plans shall be performed by December 31, 1998, for UST systems, and by January 1, 2000, for AST systems, in accordance with section 27-308(c)(2)d., for storage tank systems using vapor monitoring for release detection.
h.
Any component of a storage tank system with secondary containment shall have an interstitial monitoring method meeting the requirements of section 27-308(c)(3)a.
i.
Pressurized piping, excluding bulk product piping, shall be equipped with a line leak detector that meets the standards of section 27-308(c)(3)d.1. Gravity piping systems are exempt from this requirement.
j.
Any storage tank system not provided with a method, or combination of methods, of release detection in accordance with this section, shall be closed in accordance with section 27-317(c), by the date upon which release detection is to be provided.
k.
Groundwater and vapor monitoring wells meeting the standards for external monitoring specified in section 27-308(c)(2)a. through d., that are no longer used for release detection, shall be closed in accordance with Rule 62-532.500(4), F.A.C., by December 31, 2010. Wells not meeting these standards shall be closed in accordance with Rule 62-532.500(4), F.A.C., by December 31, 1998, unless the wells are:
1.
Used for contamination assessment purposes as specified in section 27-308(a)(2)d.; or
2.
Required by rules adopted by a County government in accordance with § 376.317, F.S.
(2)
Underground storage tank systems.
a.
By December 10, 1990, vehicular fuel petroleum storage tank systems of greater than five hundred fifty (550) gallons capacity shall be provided with release detection. Release detection for all other storage tank and integral piping systems in contact with the soil shall be provided by December 31 of the year shown in Table RD.
TABLE RD
Year Storage Year Release Detection Required Tank System Installed 1990 1991 1992 1993 Before 1970 or unknown P/RD 1970 - 1974 P RD 1975 - 1979 P RD 1980 - 1990 P RD Key to Table RD
P =
Installation of Release Detection for Pressurized Piping.
RD =
Installation of Release Detection for Tanks and Suction Piping.
b.
Effective December 31 of the applicable year specified under the schedule in Table RD, any groundwater monitoring plan or spill prevention control and countermeasure plan implemented before December 22, 1990, shall be capable of detecting the leak rate or quantity specified in section 27-308(c)(1)a.
c.
UST systems that store fuel solely for use by emergency power generators situated outside the one-foot drawdown contour of a wellfield are not required to comply with the release detection standards of section 27-308.
d.
Monitoring wells shall meet the standards of section 27-308(c)(2), by December 31, 1998. Wells that do not meet these standards shall be closed in accordance with Rule 62-532.500(4), F.A.C., by December 31, 1998, unless the wells are required by a rule that was adopted by a County government in accordance with § 376.317, F.S. However, if a monitoring well is used solely for the purpose of monitoring petroleum contamination in accordance with Chapter 62-770, F.A.C., the well does not have to be closed until the completion of the site rehabilitation pursuant to Chapter 62-770, F.A.C. Covers of leak detection monitoring wells redesignated as site assessment wells by the facility owner or operator shall be colored black with a white circle within the black background. The diameter of the white circle shall be approximately one-half the diameter of the underground utility access portal, or approximately four (4) inches.
(3)
Aboveground storage tank systems.
a.
The following methods of release detection that were implemented before March 12, 1991, shall be capable of detecting the leak rate or quantity specified in section 27-308(c)(1)a., by December 31, 1999:
1.
Any groundwater monitoring plan that meets the requirements of Rule 62-528.700, F.A.C.; or
2.
Any Spill Prevention Control and Countermeasure plan as required by 40 C.F.R. section 112.
b.
All monitoring wells used for release detection shall meet the standards in section 27-308(c)(2), by January 1, 2000, or be properly closed in accordance with Rule 62-532.500(4), F.A.C.
c.
Release detection for field-erected storage tanks with secondary containment beneath the tank shall comply with API Standard 650, Appendix I.
d.
Storage tanks upgraded with internal lining shall, by the completion of the installation of the internal lining, be provided with a method of release detection that meets the standards in section 27-308(c)(2).
e.
AST integral piping in contact with the soil shall be provided with a method, or combination of methods, of release detection. Integral piping in contact with the soil having secondary containment shall have interstitial monitoring, and single-walled integral piping in contact with the soil shall have release detection meeting the requirements of section 27-308(b)(4).
f.
Facilities using a Spill Prevention Control and Countermeasure plan as required by 40 C.F.R. section 112, for release detection, or a groundwater monitoring plan meeting the requirements of Rule 62-528.700, F.A.C., for release detection, shall meet the release detection requirements of section 27-308(b), by December 31, 1999.
g.
ASTs containing high viscosity hazardous materials are exempt from all release detection requirements except for visual inspections pursuant to section 27-308(c)(2)e.
(b)
Release Detection Methods.
(1)
General.
a.
Category-A and Category-B systems. Release detection methods shall be one of the methods specified in this section, and shall meet the performance standards contained in section 27-308(c).
b.
Category-C systems. Release detection methods shall be either interstitial or visual monitoring of secondary containment in accordance with section 27-308(c). Small diameter pressurized piping shall have a line leak detector in accordance with section 27-308(c)(3)d.1. A breach of integrity test shall be performed every five (5) years for Category-C storage tank systems with closed interstitial spaces, unless the test is a continuous test.
(2)
Underground storage tank systems. Category-A and Category-B USTs shall be equipped with one (1) or more of the following release detection systems:
a.
An interstitial monitoring system between the walls of a double-walled tank;
b.
Interstitial monitoring involving a single monitoring well or vapor detector located within a liner that meets the standards in section 27-307(a)(1)e., provided the well or detector is placed at the low point of the liner so that collected liquids will drain to the monitoring point;
c.
A continuously operating release detection system placed around a tank in an excavation or in the secondary containment in accordance with the manufacturer's requirements;
d.
A network of groundwater or vapor monitoring wells installed or verified in accordance with section 27-308(c)(2)a. through d., as applicable;
e.
Automatic tank gauge systems.
1.
An automatic tank gauge system with a tightness test of the storage tank every three (3) years; or
2.
A continuous automatic tank gauge system;
f.
A statistical inventory reconciliation system with a tightness test of the storage tank every three (3) years;
g.
Manual tank gauging shall be performed as specified in Table MTG in section 27-308(c)(3)c., for tanks of five hundred fifty (550) gallons or less nominal capacity, and for tanks five hundred fifty-one (551) to one thousand (1,000) gallons with known diameters of forty-eight (48) or sixty-four (64) inches;
h.
Manual tank gauging may be used for tanks of five hundred fifty-one (551) to two thousand (2,000) gallons nominal capacity provided that a tank tightness test is performed:
1.
Every twelve (12) months for tanks not protected from corrosion by June 30, 1992; or
2.
Every five (5) years for tanks installed with corrosion protection, or for tanks upgraded with corrosion protection by June 30, 1992. However, this method is only available for the first ten (10) years after:
a)
A tank is upgraded with cathodic protection;
b)
A single-walled corrosion-protected tank is installed; or
c)
Until December 22, 1998, whichever is later;
i.
An annual tank test in conjunction with inventory control performed in accordance with section 27-308(c). This method can only be used until:
1.
Ten (10) years after the date of installation of a single-walled corrosion protected tank;
2.
Ten (10) years after the tank is upgraded with corrosion protection or internal lining; or
3.
December 22, 1998, whichever is later.
(3)
Aboveground storage tank systems.
a.
Tanks. Category-A and Category-B ASTs shall be equipped with one (1) or more of the following release detection systems:
1.
Tanks with secondary containment shall have an interstitial monitoring system:
a)
Between the walls of a double-walled tank;
b)
In the interstice between the tank and any liner used for secondary containment;
c)
Between the tank bottom and the secondary containment for double-bottomed tanks;
2.
Tanks without secondary containment or that are exempt from secondary containment shall have a visual inspection performed in accordance with section 27-308(b)(3)b.
3.
Tanks with internal lining and cut and cover tanks shall have a method of release detection that meets the requirements of section 27-308(c)(2).
b.
Visual inspections of tank systems. A visual inspection of the exterior of each tank, the aboveground integral piping system, the secondary containment within the dike field area (if applicable), the dike field area, and any other storage system components shall be conducted and documented at least once a month, but not exceeding thirty-five (35) days.
(4)
Integral piping.
a.
Small diameter piping in contact with the soil. Single-walled piping that is in contact with soil shall be equipped with one of the following release detection systems:
1.
Suction or gravity piping shall have:
a)
An annual line tightness test; or
b)
An external monthly monitoring or release detection method meeting the requirements of section 27-308(c)(2), if designed to detect a discharge from any portion of the integral piping.
2.
By December 31, 1998, pressurized piping shall have:
a)
Mechanical line leak detectors meeting the requirements of section 27-308(c)(3)d., and either an annual line tightness test, or an external release detection method meeting the requirements of section 27-308(c)(2)a. through d.; or
b)
Electronic line leak detectors meeting the requirements of section 27-308(c)(1)a.
3.
Exemptions. Release detection is not required for piping associated with:
a)
Suction pumps, provided that a single check valve is installed directly below the suction pump, and the piping is sloped so that the contents of the pipe will drain back to the tank if the suction is broken. Written verification shall be provided by a certified contractor that no other check valves exist between the dispenser and the tank, and that the above criteria are met. Any subsequent modification of the piping which involves disconnection shall be recertified by a Certified Contractor that these conditions are still being met; and
b)
Manifold piping systems.
b.
Small diameter piping not in contact with the soil, or that is exempt from secondary containment. These systems shall be visually inspected in accordance with section 27-308(b)(3)b.
c.
Small diameter piping with secondary containment that is in contact with the soil. Double-walled piping, or single-walled piping with secondary containment shall be equipped with the following release detection systems:
1.
Interstitial monitoring;
2.
A method of testing for a breach of integrity that meets the requirements of section 27-308(c)(3)a.2., for Category-C systems, as applicable; and
3.
A line leak detector that restricts or shuts off flow or a continuously operating interstitial monitoring device that meets the requirements of section 27-308(c)(3)d.1.e), for pressurized piping connected to a UST, by December 31, 1998.
d.
Bulk product and hydrant piping.
1.
Single-walled piping in contact with the soil:
a)
Shall be pressure tested annually in accordance with section 27-308(c)(3)e.; or
b)
Instead of annual testing, a monthly release detection system meeting the requirements of section 27-308(c)(2), may be installed.
2.
Piping not in contact with the soil, or that is exempt from secondary containment, shall be visually inspected in accordance with section 27-308(b)(3)b.
3.
Piping with secondary containment that is in contact with the soil, such as double-walled piping or single-walled piping with secondary containment, shall be equipped with the following release detection systems:
a)
Interstitial monitoring; and, if applicable,
b)
For Category-C systems, a method of testing for a breach of integrity that meets the requirements of section 27-308(c)(3)a.2., for piping with closed interstitial spaces.
(c)
Performance Standards for Release Detection Methods.
(1)
General. Methods of release detection shall:
a.
Be capable of detecting a release of 0.2 gallons per hour or one hundred fifty (150) gallons within thirty (30) days with a probability of detection of 0.95, and a probability of false alarm of 0.05, with the exception of:
1.
Tightness testing requirements in section 27-308(c)(3)c.4. and (c)(3)d.2.;
2.
Visual inspections in section 27-308(c)(2)e.;
3.
Groundwater or vapor monitoring in section 27-308(c)(2); and
4.
Manual tank gauging in section 27-308(c)(3)c.1.
b.
With the exception of bailers and monitoring wells, be approved in accordance with section 27-316.
c.
Have a release detection response level described in writing for each method or combination of methods.
(2)
External release detection methods.
a.
Well construction standards.
1.
Monitoring well requirements. Monitoring wells shall be constructed and installed by a licensed water well contractor when required by Chapter 62-531, F.A.C. Monitoring wells shall:
a)
Be a minimum of two (2) inches in interior diameter;
b)
Be slotted from the bottom to two (2) feet below ground surface;
c)
Have a minimum slot size of 0.010 inch;
d)
Be backfilled with clean sand or a gravel filter pack to prevent blockage of the slots;
e)
Be constructed of at least schedule 40 PVC without any joints, or of another corrosion protected material;
f)
Be grouted into the borehole from the surface to the top of the filter pack plug with neat cement grout or other equivalent materials. Grouting shall not extend below the top of the well slotting. Bentonite slurry grouts shall not be used;
g)
Unless the monitoring well has an extended exterior casing, be equipped with a minimum six (6) inch diameter underground utility access portal designed to prevent water intrusion with a one (1) inch minimum grade increase above the surrounding surface. The well opening shall extend at least one (1) inch above the bottom of the underground utility access portal;
h)
Be equipped with a watertight cap. The well shall be kept locked or secured to prevent tampering at all times except when the monitoring well is being sampled or maintained. Monitoring wells shall be marked in accordance with API RP 1615;
i)
Extend no deeper than twenty (20) feet below ground surface. If such a depth penetrates a confining layer below the excavation, the monitoring well shall extend no deeper than to within six (6) inches of the confining layer. Any well that penetrates a confining layer shall immediately be properly abandoned in accordance with Rule 62-532.500, F.A.C.; and
j)
If installed within a secondary containment liner system, extend no deeper than six (6) inches from the liner.
2.
Groundwater monitoring wells shall:
a)
Extend at least five (5) feet below the normal groundwater surface level; and
b)
Be properly developed by the licensed water well contractor before the initial sampling.
3.
Vapor monitoring wells shall meet the requirements specified in FDEP's "Guidelines for Vapor Monitoring."
4.
Electronic sensors, probes, or fiber-optic systems shall be tested at least annually to verify that they operate in accordance with the EPGMD's approval given pursuant to section 27-316.
5.
Groundwater and vapor monitoring wells using the placement of sensors or probes in vertical, horizontal, or directionally-drilled wells shall be designed and installed in accordance with the equipment approval for that system granted in section 27-316.
b.
Site suitability determinations.
1.
A site suitability determination shall be performed for each facility using groundwater or vapor monitoring. The site suitability determination shall be performed in accordance with FDEP's "Guidelines for Site Suitability Determinations for External Monitoring" by a Professional Geologist registered in the State of Florida. If the site is not suitable for external monitoring, another method of release detection must be used.
2.
The following facilities having Category-A and Category-B USTs and ASTs that use external monitoring are not required to perform site suitability determinations:
a)
Facilities with monitoring wells located in the tank excavation, provided that a demonstration can be made that the excavation contains sand or gravel backfill, and the wells were properly constructed and installed within the backfill.
c.
Groundwater monitoring.
1.
The hazardous material shall be immiscible in water and have a specific gravity of less than one.
2.
Groundwater monitoring shall not be used for release detection after free product or a sheen is discovered in a monitoring well, unless:
a)
A Site Rehabilitation Completion Order has been issued by the FDEP following the remediation of the free product or sheen, and there is no longer any free product in the monitoring well; or
b)
Free product or sheen is not present and has not been observed in the well within the previous thirty (30) months, as demonstrated by records of at least six (6) monthly groundwater monitoring sampling events, and within the previous two (2) years, the system has been tested tight with tank and line piping tests or another internal method of release detection performed in accordance with section 27-308(c)(3).
3.
Another method of release detection specified in section 27-308(b), other than groundwater monitoring, shall be used when:
a)
There is less than one (1) foot of groundwater present in the well; or
b)
The groundwater level is above the slotted portion of the well.
4.
Records. The following information shall be maintained in accordance with the record keeping requirements of this chapter:
a)
Date of sampling;
b)
Depth of well;
c)
Depth to groundwater;
d)
Any presence of odor of stored regulated substances; and
e)
Any sheen or free product found.
d.
Vapor monitoring.
1.
Vapor monitoring can only be used to monitor hazardous materials that are sufficiently volatile to be detected in soils or groundwater by vapor monitoring equipment.
2.
The measurement of vapors in a vapor monitoring well shall not be rendered inoperative by groundwater, rainfall, soil moisture or other known interferences so that a discharge could go undetected for more than thirty (30) days.
3.
Sampling equipment shall be capable of detecting:
a)
A vapor concentration of five hundred (500) parts per million total petroleum hydrocarbons, as measured by a flame ionization detector, for storage tank systems containing gasoline or equivalent petroleum substances;
b)
A vapor concentration of fifty (50) parts per million total petroleum hydrocarbons, as measured by a flame ionization detector, for storage tank systems containing kerosene, diesel or equivalent petroleum substances;
c)
Vapor concentrations of hazardous substances or their constituents that would indicate a release; or
d)
Vapor concentrations of tracer compounds used for release detection.
4.
Vapor monitoring shall not be used for release detection if existing contamination interferes with the ability to detect a new release.
5.
The vapor monitoring plan shall be developed and performed in accordance with FDEP's "Guidelines for Vapor Monitoring." The plan shall include a description of monitoring wells or probes, the method of sampling, the establishment of a release detection response level and the data management procedures. Facilities with monitoring wells located in the tank excavation do not have to meet the requirements for FDEP's "Guidelines for Site-Suitability Determinations for External Monitoring," provided that a demonstration can be made that the excavation contains sand or gravel backfill, and the wells were properly constructed and installed within the backfill.
e.
Visual inspections. Any visual inspection of the storage tank system or its secondary containment that reveals signs of corrosion, cracks, structural damage, leakage, or other similar problems shall be noted. Repairs shall be made in accordance with the requirements of section 27-309.
(3)
Internal release detection methods.
a.
Interstitial monitoring for UST and AST systems.
1.
Interstitial monitoring for double-walled tanks, double-walled integral piping, dispenser liners, piping sumps, and other secondary containment systems, shall be designed and constructed to allow monitoring of the space between the primary and secondary containment. One or more of the following methods of interstitial monitoring shall be used:
a)
Manual sampling of, or visual monitoring for, liquids;
b)
Continuous electronic sensing equipment;
c)
Hydrostatic monitoring systems; or
d)
Vacuum monitoring.
2.
Breach of integrity tests for Category-C systems. A test shall be performed for a breach of integrity of the interstice for double-walled USTs, double-bottomed ASTs, and for double-walled integral piping that is in contact with the soil and that is connected to ASTs or USTs. Double-walled shop-fabricated ASTs, piping sumps, and dispenser liners are not required to perform a breach of integrity test. The test shall be performed to determine the integrity of the inner and outer wall, is required only for tanks and integral piping with closed interstices, and does not apply to open-interstice systems with liners. The test shall be performed at the time of installation, and every five (5) years from the date of installation, unless the test is a continuous test. If a UST is totally submerged in groundwater, monthly monitoring of the interstice for the presence of water shall be conducted. The breach of integrity test may be performed by using at least one (1) of the following methods:
a)
A continuous hydrostatic system approved by the Department in accordance with section 27-316;
b)
A continuous vacuum system, pursuant to section 27-308(c)(3)a., that is approved by the Department in accordance with section 27-316;
c)
Testing of the interstice for liquid tightness in accordance with manufacturer's installation instructions; or
d)
Another method in accordance with section 27-316.
3.
Vacuum monitoring of the interstice shall meet the following requirements:
a)
Liquid-filled gauges and air-filled gauges shall be calibrated in accordance with the National Institute of Standards and Technology. The gauges shall be operational at all times.
b)
Vacuum monitoring may be used as a continuous method of release detection provided that the vacuum system is equipped with an audible or visual alarm. The alarm shall indicate when the minimum vacuum level allowed is reached as provided in the equipment approval granted in accordance with section 27-316.
c)
Vacuum readings shall be recorded monthly. Upon discovery of any significant vacuum level decrease, or any loss of vacuum exceeding twenty (20) percent of the initial level, or any loss in excess of the levels established in the test protocols provided in the third party certification for the test method, the tank manufacturer shall be contacted and the vacuum refreshed in accordance with the storage tank system's equipment approval in section 27-316. If the loss of vacuum persists, an investigation shall be initiated and an incident reported in accordance with section 27-305(b). The source of the loss shall be repaired in accordance with section 27-309.
4.
Interstitial monitoring for storage tanks and integral piping equipped with liners shall be designed and constructed to allow monitoring of the space between the primary and secondary containment and shall:
a)
Be capable of detecting a release through the inner wall into the interstice;
b)
Be constructed and installed so that groundwater, rainfall, or soil moisture will not render the testing or sampling method used inoperative; and
c)
Be equipped with an external release detection method meeting the standards of section 27-308(c)(2)a. through d., except for the groundwater level and excavation zone assessment requirements; or
d)
Be visually inspected in accordance with section 27-308(c)(2)e.; or
e)
Be equipped with a monitoring device approved in accordance with section 27-316, installed at the monitoring point within the liner.
b.
Inventory control.
1.
General.
a)
Inventory control shall be maintained for each single-walled tank that contains vehicular fuel.
b)
Storage tank systems that are elevated above the soil or that have secondary containment are exempt from inventory control requirements. ASTs that rest on an impervious surface are also exempt.
2.
Inventory control for USTs and shop-fabricated ASTs shall be performed and recorded in accordance with API RP 1621, as applicable. Manifolded tanks may be treated as a single tank for the purposes of inventory control. Inventory control shall be performed in the following manner:
a)
Volume measurements for product inputs, withdrawals, and the amount remaining in each tank shall be recorded each operating day;
b)
Measurements of product levels shall be recorded to the nearest one-eighth of an inch;
c)
Product inputs shall be reconciled with delivery receipts by measurement of the tank product volume before and after delivery;
d)
Product dispensed shall be metered as required by Chapter 525, F.S. and Chapter 531, F.S. and in accordance with the standards established by the Florida Department of Agriculture and Consumer Services in Chapter 5F-2, F.A.C.;
e)
The measurement of water level in the bottom of the tank shall be made at least once a week to the nearest one-eighth of an inch; and
f)
The significant loss or gain of product shall be calculated for each month.
3.
Inventory control requirements for USTs. Water fluctuations exceeding one (1) inch not attributed to deliveries shall be investigated in the following manner:
a)
The accessible parts of the storage system shall be inspected for damage or openings;
b)
Release detection systems shall be checked for signs of a discharge; and
c)
If, within a week, the investigation does not reveal the source of the water fluctuation, the entire storage tank system shall be tested in accordance with section 27-308(c)(3).
4.
Inventory control requirements for field-erected ASTs.
a)
Bulk product facilities may use product inventory control for multiple tanks provided that a demonstration of equivalent protection is made in accordance with section 27-316.
b)
Inventory measurements for field-erected systems, manifolded systems, and non-manifolded systems with a capacity of thirty thousand (30,000) gallons or greater shall be reconciled to detect the presence of a significant loss or gain. The equipment and method used shall be capable of accurately measuring the level or volume of product over the full range of the tank's usable storage capacity, to the nearest one-quarter of an inch.
5.
Investigation procedures for significant loss or gain. An investigation shall be initiated immediately to determine the source of a significant loss or gain. The entire storage tank system, excluding the vent, but including piping connections and remote fill lines, shall be tested or inspected to determine if the system is product tight. The investigation shall continue until the source has been found, using the following investigative procedure:
a)
Inventory records shall be checked for errors in arithmetic, data recording, and measurement;
b)
If the significant loss or gain is not reconcilable or cannot be affirmatively demonstrated to be the result of theft, the accessible parts of the storage system shall be checked for damage or leaks;
c)
Release detection systems shall be checked for signs of a discharge;
d)
Calibration of the inventory measuring system and dispensing system shall be verified;
e)
If the investigation does not reveal the source of the significant loss or gain within one (1) week for USTs, and two (2) weeks for ASTs, or if the EPGMD determines that it is necessary to investigate based on evidence that the significant loss or gain could result in potential harm to the environment, the storage tank system shall be tested in accordance with the manufacturer's guidelines, if applicable, and section 27-308(c)(3) and (4); and
f)
If a discharge is discovered, the leaking or defective component of the storage tank system shall be repaired in accordance with section 27-309. If the storage tank system cannot be repaired, it shall be closed in accordance with section 27-317(c).
c.
Underground storage tanks.
1.
Manual tank gauging. Manual tank gauging for tanks of two thousand (2,000) gallons or less containing hazardous material shall meet the following requirements:
a)
Tank liquid level measurements shall be taken weekly at the beginning and ending of a period between thirty-six (36) hours and fifty-eight (58) hours in accordance with Table MTG, during which no liquid is added to or removed from the tank;
b)
Level measurements shall be based on an average of two (2) consecutive stick readings taken at both the beginning and ending of the period; and
c)
The equipment used shall be capable of measuring the level of product over the full range of the tank's height to the nearest one-eighth of an inch.
d)
Readings exceeding the standards described in Table MTG shall be investigated in accordance with section 27-315.
TABLE MTG
Nominal Tank Capacity Minimum Duration of Test Weekly
Standard
(One Test)Monthly
Standard
(Average of Four Tests)550 gallons or less 36 hours 10 gallons 5 gallons 551—1,000 gallons
(Tank diameter is <64″)44 hours 9 gallons 4 gallons 551—1,000 gallons
(Tank diameter is <48″)58 hours 12 gallons 6 gallons 551—1,000 gallons
(Tank diameter unknown)36 hours 13 gallons 7 gallons 1,001—2,000 gallons 36 hours 26 gallons 13 gallons 2.
Automatic tank gauge systems.
a)
Automatic tank gauge systems that do not analyze data in a continuous manner shall be placed in a test mode at least once every thirty (30) days.
b)
Automatic tank gauge systems that continuously analyze the data collected by the system shall be operated in continuous test mode at all times and shall provide test results daily.
3.
Statistical Inventory Reconciliation (SIR). SIR shall be conducted according to the following requirements:
a)
Data submitted for SIR analysis must be gathered in accordance with the requirements of sections 27-308(c)(3)b.2.a) through e);
b)
Results of each monthly analyses must include the calculated results from the data set for leak threshold, the minimum detectable leak rate, the calculated leak rate, and a determination of whether the result of the test was Pass, Fail, or Inconclusive. For the purposes of this section, the "leak threshold" is defined as the specific leak threshold of the SIR method approved in accordance with section 27-316, to meet the release detection level specified in section 27-308(c)(1)a.;
c)
Pass means that the calculated leak rate for the data set is less than the leak threshold and the minimum detectable leak rate is less than or equal to the certified performance standard (0.2 gph);
d)
Fail means that the calculated leak rate for the data set is equal to or greater than the leak threshold;
e)
Inconclusive means that the minimum detectable leak rate exceeds the certified performance standard (0.2 gph) and the calculated leak rate is less than the leak threshold. If for any other reason the test result is not a pass or fail, the result is inconclusive;
f)
An Incident Notification Form shall be submitted to the County when a monthly SIR report of Fail is received;
g)
An Incident Notification Form shall be submitted to the County after the receipt of two (2) consecutive monthly SIR reports of Inconclusive. An investigation shall be performed in accordance with the Incident Response requirements specified in section 27-315. However, if at the end of the fourteen (14) day investigation period provided in section 27-315(a), the SIR data from the previous month is still inconclusive, a tightness test of the system shall be performed;
h)
A data set shall consist of at least one (1) month of valid data gathered over a time period not exceeding thirty-five (35) days. A minimum of twenty (20) data points over this thirty-five (35) day period shall be used to calculate the leak rate unless the vendor of the SIR system approved under section 27-316, has provided a third party determination that a lesser number of data points is capable of detecting a release of 0.2 gph or one hundred fifty (150) gallons within thirty (30) days with a probability of detection of 0.95 and a probability of false alarm of 0.05; and
i)
Results of monthly evaluations shall be recorded on Form 62-761.900(7), F.A.C., or on another similar form that provides the same information. These forms shall be kept as records in accordance with section 27-311.
4.
Tightness testing.
a)
Tightness testing for all tanks shall be capable of detecting a 0.1 gph leak rate with a probability of detection of 0.95 and a probability of false alarm of 0.05 from any portion of the tank. Tightness testing shall account for the effects of thermal expansion or contraction of the hazardous material, vapor pockets, tank deformation, evaporation or condensation, and the location of the water table.
b)
If any volumetric tank tightness test is conducted at a level lower than the overfill protection device set point, a non-volumetric test shall also be used to test the ullage portion of the tank. When volumetric tests are conducted, there must be a minimum pressure differential of plus or minus one psig (pounds per square inch gauge), measured at the bottom of the tank, between the product hydrostatic pressure inside the tank and the hydrostatic pressure due to the external water table. When using this method, positive field verification of the depth of the water table must be performed, and the minimum liquid level of product in the tank shall be at least thirty (30) percent of tank capacity, provided that the third party evaluation for the test method verifies detection capability at this level. If the water table depth cannot be verified, the minimum liquid level for volumetric tank testing shall be sixty-five (65) percent of tank capacity.
c)
Tank and line tightness testing shall be performed in accordance with Chapter 4 of NFPA 329.
d)
Overfill protection and spill containment devices shall be inspected before a tightness test is performed to ensure that these devices do not interfere with the test, and after the test to ensure that the devices are operating properly.
d.
Small diameter integral piping in contact with the soil.
1.
Line leak detectors for USTs. Line leak detectors shall:
a)
Be capable of detecting a discharge of 3.0 gph with a probability of detection of 0.95 and a probability of false alarm of 0.05 at a line pressure of 10 psi within one (1) hour;
b)
Have an annual test of the operation of the leak detector conducted in accordance with the manufacturer's requirements by an individual certified or trained by the manufacturer to determine whether the device is functioning as designed. Remote testing of the leak detector can be performed by the manufacturer if the remote test is approved under section 27-316;
c)
Restrict flow within one (1) hour if designed with mechanical flow restriction;
d)
When a discharge of 3.0 gph is detected, shut off power to the pump if designed with automatic electronic shutoff. When in test mode, line leak detectors with automatic electronic shutoff shall also be able to detect a discharge of 0.2 gph at a line pressure of one hundred fifty (150) percent of operating pressure, or an equivalent leak rate, with a probability of detection within a one (1) month period of at least 0.95 and a probability of false alarm of no more than 0.05. When a discharge of 0.2 gph is detected, the leak detector shall provide audible or visual alarms that can be clearly heard or seen by the operator of the facility, or if monitored remotely on a real time basis, the alarm condition must be immediately transmitted from the remote location to the facility operator; and
e)
Instead of using a line leak detector as a method of release detection for pressurized small diameter piping associated with double-walled integral piping, a continuously operating interstitial monitoring device can be used. Continuously operating interstitial monitoring devices shall be capable of detecting a release of ten (10) gallons within one (1) hour and shutting off the pump.
2.
Tightness testing. Tightness testing for pressurized piping in contact with the soil shall be capable of detecting a 0.1 gallon per hour leak rate at one and one-half times the operating pressure with a probability of detection of 0.95 and a probability of false alarm of 0.05.
e.
Bulk product piping.
1.
An annual test shall be performed of single-walled bulk product piping in contact with the soil. Prior to testing the piping system, a leak tightness evaluation of all exposed components shall be performed through visual inspection, or by another method approved by the EPGMD in accordance with section 27-316. The evaluation shall be verified and recorded. One of the following methods shall be used for the annual test:
a)
A bulk product piping test method approved in accordance with section 27-316;
b)
An API RP 1110 hydrostatic test; or
c)
An ASME B31.4 hydrostatic test.
2.
Double-walled bulk product and hydrant piping, and other bulk piping equipped with secondary containment shall have methods of release detection and testing for a breach of integrity that meet the requirements of section 27-308(c)(3)a.2. or 4., as applicable.
3.
Records of all test results shall be maintained in accordance with the Appendix-Test Records of API RP 1110, or Chapter VI of ASME B31.4, as applicable, pursuant to section 27-311(a).
(Ord. No. 1999-46, § 1, 8-31-99; Ord. No. 2005-11, §§ 4, 9, 5-24-05; Ord. No. 2009-56, § 1, 8-25-09)