N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 598-3.3

Current through Register Vol. 46, No. 50, December 11, 2024

Section 598-3.3 - Leak detection

(a) General leak detection requirements. A method, or combination of methods, of leak detection must be provided that:

(1) can assess the integrity and remaining useful life of tank system and detect a leak from any portion of the tank and the piping that are in contact with the ground and routinely contain hazardous substance;

(2) is installed and calibrated in accordance with the manufacturer's instructions; and

(3) meets the requirements of subdivisions (c) and (d) of this section, as applicable. In addition, the methods listed under paragraphs (c)(1), (d)(1), and (d)(2) of this section must be capable of detecting the leak rate or quantity specified for that method with a probability of detection of 95 percent and a probability of false alarm of 5 percent.

(b) Specific leak detection requirements for tanks and piping.

(1) Tank leak detection.

(i) Category 1 tanks. Category 1 tanks must, at least every five years, be inspected in accordance with paragraph (c) (3) of this section. If thinning of one millimeter per year or greater occurs on the tank walls, or the calculated expected remaining useful life as determined by the inspection is less than 10 years, then reinspection must be performed on the tank at one half of the remaining useful life.

(ii) Category 2 tanks. Category 2 tanks must be monitored in accordance with the following:

('a') Category 2 tanks must, at least every five years, be inspected in accordance with paragraph (c)(3) of this section. If thinning of one millimeter per year or greater occurs on the tank walls, or the calculated expected remaining useful life as determined by the inspection is less than 10 years, then reinspection must be performed on the tank at one half of the remaining useful life; and

('b') Category 2 tanks must have a system for monitoring leakage between the tank bottom and the secondary containment system. This may include perforated gravity collection piping or channels in a concrete foundation, or other equivalent method acceptable to the department. Monitoring may be accomplished by visual, mechanical, electronic or other means acceptable to the department. Tanks which are entirely aboveground, such as tanks on racks, cradles or stilts, may be visually monitored for leakage to meet this requirement. This monitoring must be performed in accordance with the frequencies in subdivision 3.2(c) of this Subpart.

(2) Piping leak detection. All piping in contact with the ground must be monitored for leaks at weekly intervals in accordance with paragraph (c)(2) of this section. Additionally, all piping in contact with the ground that conveys hazardous substance under pressure must be equipped with an automatic line leak detector that is operated in accordance with paragraph (d)(1) of this section. No leak detection is required for suction piping that is demonstrated to be designed and constructed to meet the following standards:

(i) The piping operates at less than atmospheric pressure.

(ii) The piping is sloped so that the contents of the pipe will drain back into the tank if the suction is released.

(iii) Only one check valve is included in each suction line.

(iv) The check valve is located directly below and as close as practicable to the suction pump.

(c) Tank leak detection methods. Tank leak detection methods used to meet the requirements of paragraph (b) (1) of this section must be conducted in accordance with the following:

(1) Tank tightness testing.

(i) A tightness test is a test acceptable to the department which will determine if a tank and piping system is tight or not tight. This shall include:

('a') a test capable of detecting a tank leak of one tenth gallons per hour (gph) with a probability of detection of 95 percent and probability of false alarm of five percent or less with a maximum threshold for declaring a leak of five hundredths of a gallon in one hour accounting for variables such as vapor pockets, thermal expansion and contraction of product, temperature stratification, groundwater level, evaporation, pressure and tank deformation; or

('b') a structural inspection performed in accordance with the requirements of paragraph (3) of this subdivision.

(ii) If it is technically impossible to perform a meaningful tightness test, then an alternative test or inspection which is acceptable to the department must be performed.

(iii) Qualification of technicians. All tightness tests must be performed by a qualified technician who has an understanding of the variables which affect the test and is trained by the manufacturer or their representative to perform the test.

(2) Interstitial monitoring. Interstitial monitoring between the primary and secondary containment may be used if the monitoring equipment is designed, constructed and installed to detect a leak from any portion of the tank that routinely contains hazardous substance, and if the monitoring equipment meets the requirements of either subparagraph (i) or (ii) of this paragraph:

(i) For a double-walled tank or double-walled piping, the sampling or testing method:

('a') can detect a leak through the inner wall in any portion of the tank and/or piping that routinely contains hazardous substance; and

('b') is capable of detecting a breach in both the inner and outer walls of the tank and/or piping if using continuous vacuum, pressure, or liquid-filled methods of interstitial monitoring.

(ii) For an AST system with secondary containment within the excavation zone, the sampling or testing method can detect a leak between the primary and secondary containment, and the following conditions are met:

('a') The secondary containment consists of artificially constructed material that is sufficiently thick and impermeable (i.e., with a permeability rate to water equal to or less than 1'10-6 cm/sec) to direct a leak to the monitoring point and permit its detection.

('b') The secondary containment is compatible with the hazardous substance stored so that a leak from the AST system will not cause a deterioration of the secondary containment, allowing a leak to pass through undetected.

('c') For cathodically protected tank systems the secondary containment must be installed so that it does not interfere with the proper operation of the cathodic protection system.

('d') The groundwater, soil moisture, or rainfall will not render the testing or sampling method inoperative so that a leak could go undetected for more than seven days.

('e') The site is assessed to ensure that the secondary containment is always above the groundwater and not in a 25-year flood plain, unless the secondary containment and monitoring designs are for use under such conditions.

('f') Monitoring wells must be protected from traffic, permanently labeled as a 'monitoring well' or 'test well-no fill' and equipped with a locking cap which must be locked when not in use to prevent unauthorized access and tampering.

(3) Five-year inspections.

(i) The owner or operator must inspect the aboveground tank system. The inspection must be consistent with a consensus code, standard or practice, and be developed by a nationally recognized association or independent testing laboratory and meet the specifications of this paragraph. If no consensus code, standard, or practice is applicable to the tank system, a method otherwise approved by the department must be used. The inspection must consist of the following:

('a') a calculated useful remaining life of the tank. The calculated useful remaining life of the tank may not exceed the useful life as determined by the manufacturer;

('b') a determination of tank system tightness in accordance with paragraphs (c)(1) and (d)(2) of this section;

('c') an evaluation on structural soundness of the tank system;

('d') an assessment of tank system corrosion, wear, and operability; and

('e') an evaluation on foundation strength.

(ii) For aboveground ancillary equipment, the inspection must consist of the following:

('a') examination of exposed piping, joints, welds and connections for misalignment and tightness. Insulated piping systems must have the covering removed if there is evidence of a leak such as damage or discoloration of the insulating material or the presence of free liquid. Representative flanged connections must be examined for gasket deterioration and misalignment;

('b') structural inspection of representative sections of pipes for thinning, galvanic corrosion, intergranular corrosion, stress corrosion cracking, crevice corrosion, pitting, and for evidence of coating failure and material incompatibility. Galvanic cells, such as may be created by the joining of dissimilar metals, and other sources of corrosion must be identified;

('c') a tightness test of any connecting piping in contact with the ground in accordance with paragraph (d)(2) of this section;

('d') inspection and assessment of all ancillary equipment such as gauges, pressure/vacuum safety valves, safety interlocks, flow valves and pumps for adequacy, operability, leakage, fouling, corrosion, scaling and wear.

Relief valves must be tested for capacity or opening and reseating pressure and inspected to see if corrosion, fouling or scaling has occurred; and

('e') an identification of system deficiencies which may result in a leak due to vibration, expansion, contraction, frost, settlement, shock or other causes.

(iii) For tanks with a capacity of 10,000 gallons or more, the inspection must be conducted under the direction of a qualified engineer. The engineer must certify that the tank is structurally sound and is not subject to external or internal corrosion that may result in a release before the next inspection and re-certification. Where necessary, the inspection must be made of all accessible tank surfaces and, where applicable, include the following:

('a') cleaning the tank and difficult-to-reach areas within the tank in accordance with a consensus code, standard or practice developed by a nationally recognized association or independent testing laboratory;

('b') removal, transportation and disposal of solid precipitates or accumulated sludge in compliance with all applicable State, Federal and local laws;

('c') inspecting the tank, both internally and externally, for structural soundness and testing of the welds and seams on the tank bottom for porosity and tightness. The inspector may use one or more of the following nondestructive testing methods: hydrostatic or vacuum test; a dye penetrant test; an ultrasonic test; a radiographic or X-ray test; a magnetic particle inspection; or any other equivalent test which determines whether the tank is structurally sound. This must include measurements of erosion and corrosion wear and assessments of galvanic corrosion, intergranular corrosion, stress corrosion cracking, device corrosion, pitting, cellular corrosion and inspection for material incompatibility;

('d') visual inspection of the internal surfaces of the tank and difficult-to-reach areas for corrosion or failure; and

('e') inspection of internal and external liners, cladding and coatings for any signs of failure such as cracks, bubbles, blisters, peeling, curling or separation.

(d) Piping leak detection methods. Piping leak detection methods used to meet the requirements of paragraph (b)(2) of this section must be conducted in accordance with the following:

(1) Automatic line leak detectors. Methods which indicate the presence of a leak by restricting or shutting off the flow of hazardous substance through piping, or triggering an audible or visual alarm, may be used only if they detect leaks of 3 gallons per hour at 10 pounds per square inch line pressure within one hour.

(2) Line tightness testing.

(i) A tightness test is a test acceptable to the department which will determine if a tank and piping system is tight or not tight. This shall include:

('a') a test capable of detecting a piping leak of one tenth gallons per hour (gph) with a probability of detection of 95 percent and probability of false alarm of five percent or less with a maximum threshold for declaring a leak of five hundredths of a gallon in one hour accounting for variables such as vapor pockets, thermal expansion and contraction of product, temperature stratification, groundwater level, evaporation, pressure and tank deformation; or

('b') a structural inspection performed in accordance with the requirements of paragraph (c)(3) of this section.

(ii) If it is technically impossible to perform a meaningful tightness test, then an alternative test or inspection which is acceptable to the department must be performed.

(e) Recordkeeping. Records of the tests and inspections required by this section must meet the following requirements:

(1) The results of five-year inspections must be retained for 10 years.

(2) The results of tank and line tightness testing must be retained for three years or until the next test, whichever is later, and include the following information:

(i) facility registration number;

(ii) tank system identification number as shown on the registration certificate for the tank or piping tested;

(iii) date of test;

(iv) results of test;

(v) test method;

(vi) certification by the technician that the test complies with paragraph (c)(1) or paragraph (d)(2) of this section;

(vii) statement of technician's qualifications;

(viii) address of technician; and

(ix) signature of technician.

(f) Uninspected tank systems. If any portion of a tank system is not tested or inspected as required by this section, the owner or operator must take the uninspected portion of the tank system out-of-service pursuant to the requirements of subdivision 3.6(a) of this Subpart.

N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 598-3.3

Adopted New York State Register July 19, 2023/Volume XLV, Issue 29, eff. 10/17/2023