Study guide
3.2 Aboveground (AST) & Underground Storage Tank (UST) Standards
Certified Hazardous Materials Manager CHMM
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1 Chapter 1: Planning and Management of Hazardous Materials
1.1 Hazard Identification & GHS Classification 1.2 Safety Data Sheets (SDS) & Chemical Compatibility 1.3 Life-Cycle Management, Source Reduction & Pollution Prevention 1.4 Chemical Inventory & Regulatory Applicability Framework 1.5 Pollution Prevention Opportunity Assessments (PPOA) & P2 Program Implementation
2 Chapter 2: Shipping and Transporting Hazardous Materials
2.1 DOT HazMat Classification & Table 172.101 2.2 Packaging Standards, Marking, Labeling & UN Specifications 2.3 Shipping Papers, Uniform Hazardous Waste Manifest & e-Manifest 2.4 Placarding Requirements, Exceptions & Modal Transport
3 Chapter 3: Storage of Hazardous Materials
3.1 RCRA Container Storage & Inspection Requirements 3.2 Aboveground (AST) & Underground Storage Tank (UST) Standards 3.3 Secondary Containment Design & Sizing Calculations 3.4 Chemical Segregation, Flammable Liquids & Compressed Gas Storage
4 Chapter 4: Facility Operations & Environmental Permitting
4.1 Process Safety Management (PSM) & Risk Management Plan (RMP) 4.2 Spill Prevention, Control, and Countermeasure (SPCC) & Facility Response Plans 4.3 Clean Air Act: Operating Permits, NESHAP & Emission Controls 4.4 Clean Water Act: NPDES, Industrial Wastewater Pretreatment & SWPPP
5 Chapter 5: Disposition of Hazardous Materials & Waste Management
5.1 RCRA Hazardous Waste Determination: Characteristic & Listed Wastes 5.2 Generator Categories (VSQG, SQG, LQG) & Accumulation Rules 5.3 Satellite Accumulation Areas (SAA) & Universal Waste Management 5.4 Used Oil Management, Land Disposal Restrictions (LDR) & TSDF Operations 5.5 Waste Profiling, Disposal Vendor Qualification & Final Disposition Documentation
6 Chapter 6: Regulatory Recordkeeping & Reporting
6.1 EPCRA Tier II (Section 312) & Toxic Release Inventory (TRI Section 313) 6.2 RCRA Biennial Reporting, Exception Reports & TSCA Reporting 6.3 Regulatory Record Retention Periods & Compliance Documentation
7 Chapter 7: Personnel Training Programs & Competency
7.1 HAZWOPER Training Standards (29 CFR 1910.120) & Emergency Roles 7.2 DOT HazMat (49 CFR 172) & RCRA Generator Training Mandates 7.3 OSHA Hazard Communication Training, Adult Learning & Competency Evaluation
8 Chapter 8: Emergency Response, Incident Command & Recovery
8.1 Emergency Response Planning & Incident Command System (ICS/NIMS) 8.2 Spill Notification: Reportable Quantities (RQ), NRC, SERC & LEPC 8.3 Spill Containment, Mitigation Techniques & Air Monitoring 8.4 Decontamination Procedures, Site Control Zones & Post-Incident Recovery
9 Chapter 9: Environmental Remediation & Site Assessment
9.1 Environmental Site Assessments: ASTM Phase I & Phase II ESA 9.2 CERCLA Superfund Process & RCRA Corrective Action 9.3 In-Situ Remediation Technologies (ISCO, SVE, Bioremediation, PRBs) 9.4 Ex-Situ Remediation Technologies, Risk-Based Corrective Action (RBCA) & CSM
10 Chapter 10: Environmental Management Systems & Compliance Auditing
10.1 ISO 14001:2015 Environmental Management Systems (EMS) & PDCA 10.2 Environmental Auditing Protocols & EPA Audit Policy (Self-Disclosure) 10.3 Root Cause Analysis, CAPA Systems & IHMM Code of Ethics 10.4 Regulatory Currency, Rulemaking Participation, Public Outreach & Environmental Cost Analysis
11 Chapter 11: Environmental Fate, Hydrogeology & Sampling
11.1 Chemical Fate and Transport Mechanisms (Partitioning, Darcy's Law, Advection) 11.2 Soil, Groundwater & Air Sampling Protocols and Chain of Custody 11.3 Data Quality Objectives (DQOs), Analytical Methods & PARCC Parameters 11.4 Human Health & Ecological Risk Assessment (HQ, Hazard Index, Cancer Risk)
12 Chapter 12: Occupational Health, Industrial Hygiene & Safety
12.1 Industrial Hygiene Principles (AREC) & Occupational Exposure Limits (PEL, TLV, REL, IDLH) 12.2 Chemical Toxicology, Routes of Entry & Dose-Response (LD50, LC50) 12.3 Hierarchy of Controls & Engineering Solutions 12.4 Personal Protective Equipment (Levels A-D) & Respiratory Protection Programs (APF, MUC) 12.5 Industrial Hygiene Monitoring Equipment (PID, FID, Multi-Gas Meters, Noise & Heat Stress) 12.6 Job Hazard Analysis (JHA), the HAZWOPER Site Safety and Health Plan (HASP) & Required Written Programs
3.2 Aboveground (AST) & Underground Storage Tank (UST) Standards
Key Takeaways Explain This Topic AI
Under EPA SPCC (40 CFR Part 112), a facility is subject to Spill Prevention, Control, and Countermeasure rules if it has an aggregate aboveground oil storage capacity exceeding 1,320 gallons (counting containers ≥ 55 gal) or completely buried oil storage > 42,000 gallons.
Aboveground Storage Tank (AST) mechanical integrity testing follows STI SP001 and API 650/653 standards, utilizing a tiered regime of monthly visual owner inspections, annual formal checks, and periodic non-destructive external/internal ultrasonic integrity testing.
RCRA Subpart J (40 CFR Parts 264/265) hazardous waste tank systems require a written tank integrity assessment certified by an independent, qualified Professional Engineer (PE), daily inspections of overfill controls, and weekly visual inspection of aboveground tank components.
Underground Storage Tanks (USTs, 40 CFR Part 280) are defined as any tank system with at least 10% of its combined volume (including connected piping) beneath the ground surface, excluding heating-oil tanks used for consumptive use on the premises regardless of size; the separate 1,100-gallon limit applies to qualifying farm or residential motor-fuel tanks.
2015 Revised UST regulations mandate secondary containment with continuous interstitial monitoring for all new tank and piping installations, overfill prevention (automatic shutoff at 95% capacity or alarms at 90%), cathodic protection (with 60-day rectifier logs and 3-year tester certification), and line leak detectors (ELLD detecting 3 gph at 10 psi within 1 hour).
Last updated: August 2026
Aboveground (AST) & Underground Storage Tank (UST) Standards
Bulk liquid storage in industrial facilities is governed by two major regulatory frameworks: the Spill Prevention, Control, and Countermeasure (SPCC) program under 40 CFR Part 112 (promulgated under the Clean Water Act) for petroleum and non-petroleum oils, and the Underground Storage Tank (UST) regulations under 40 CFR Part 280 (promulgated under RCRA Subtitle I). In addition, hazardous wastes accumulated in stationary vessels are governed by RCRA Subpart J (40 CFR Parts 264/265).
Environmental managers must navigate these multifaceted engineering codes, non-destructive testing regimes, cathodic protection systems, and automated release detection technologies.
1. Aboveground Storage Tanks: SPCC Applicability & Tiered Integrity Framework (40 CFR Part 112)
The EPA's SPCC rule (40 CFR Part 112) applies to non-transportation-related onshore and offshore facilities that store, use, process, or consume oil or oil products, provided the facility meets both of the following criteria:
Threshold Storage Capacity:
Aboveground Aggregate Capacity: Exceeds 1,320 U.S. gallons (counting only containers, drums, tanks, and oil-filled equipment with a capacity of 55 gallons or greater ).
OR Completely Buried Oil Storage Capacity: Exceeds 42,000 U.S. gallons (excluding USTs regulated under 40 CFR Part 280).
Reasonable Expectation of Discharge: The facility could reasonably be expected to discharge oil in harmful quantities into or upon the navigable waters of the United States or adjoining shorelines. +-----------------------------------------------------------------------------+
- | SPCC APPLICABILITY ALGORITHM |
- | |
- | [STEP 1: INVENTORY OIL CONTAINERS ≥ 55 GALLONS] |
- | - Count all bulk ASTs, totes, 55-gal drums, and transformers. |
- | - Ignore containers < 55 gallons (e.g., 5-gal pails, 1-qt oil cans). |
- | | |
- | v |
- | [STEP 2: SUM AGGREGATE SHELL CAPACITY] |
- | - If Total Capacity > 1,320 Gallons: SPCC APPLIES. |
- | - If Total Capacity ≤ 1,320 Gallons: SPCC DOES NOT APPLY. |
- | | |
- | v |
- | [STEP 3: TIERED PLAN DETERMINATION] |
- | - Tier I Qualified: Total storage ≤ 10,000 gal, no individual AST > 5,000 |
- | gal, no reportable discharge (Self-certified Plan template). |
- | - Tier II Qualified: Total storage ≤ 10,000 gal, has AST > 5,000 gal |
- | (Self-certified Plan without template). |
- | - Non-Qualified / Standard: Total storage > 10,000 gal OR spill history |
- | (Requires certification by a licensed Professional Engineer [PE]). |
- +-----------------------------------------------------------------------------+
- 2. AST Engineering Standards: STI SP001 & API 650 / 653 Inspection Regimes
Under 40 CFR § 112.8(c)(6) , bulk storage ASTs must be tested for integrity on a regular schedule. Industry consensus codes dictate the inspection frequency and testing methodology:
1. STI SP001 (Steel Tank Institute Standard for the Inspection of Aboveground Storage Tanks)
Applies primarily to shop-fabricated welded steel ASTs, portable tanks, and small field-erected tanks up to 75,000 gallons.
Monthly Visual Inspections: Performed and documented by facility personnel using an STI inspection checklist (checking shell condition, secondary containment, valves, vents, overfill gauges, and signs of leakage).
Annual Visual Inspections: Formal documented visual review by designated personnel, including foundation stability, anchor bolts, ladder/walkway safety, and cathodic protection monitoring.
Periodic Formal External / Internal Inspections: Conducted by a certified STI inspector using ultrasonic thickness (UT) testing, liquid penetrant testing, and vacuum box testing at intervals of 5, 10, 15, or 20 years depending on tank category (Category 1: spill control with continuous release detection mechanism [CRDM]; Category 2: spill control without CRDM; Category 3: no spill control).
2. API 650 & API 653 (American Petroleum Institute)
API 650: Standards for design, construction, and welding of large field-erected vertical carbon and stainless steel storage tanks.
API 653: In-service inspection, repair, alteration, and reconstruction standard for field-erected bulk storage tanks. Mandates visual external inspection every 5 years and formal internal ultrasonic floor inspection at intervals not exceeding 10 to 20 years based on corrosion rate calculations: T_interval = (t_actual - t_minimum) / (2 × Corrosion Rate).
3. RCRA Hazardous Waste Tank Systems (40 CFR Parts 264/265 Subpart J)
Stationary tanks used to treat or accumulate hazardous waste must comply with RCRA Subpart J :
Written PE Integrity Assessment (40 CFR § 265.191 / § 264.191): Every tank system must have a written assessment reviewed and certified by an independent, qualified, registered Professional Engineer (PE) confirming structural integrity, wall thickness, and corrosion protection.
Secondary Containment (§ 265.193): Must encompass the entire tank, ancillary piping, and sumps. Must include an external liner, vault, or double-walled tank constructed of impermeable materials with a leak detection system capable of detecting a release within 24 hours.
Inspection Frequencies (§ 265.195):
Daily (every operating day): Overfill/spill control equipment, monitoring and data gauges (pressure, temperature), and the tank exterior to detect corrosion or releases.
Weekly: Aboveground portions of the tank system and secondary containment area for signs of deterioration or standing liquids.
4. Underground Storage Tanks (UST): Regulatory Scope & 40 CFR Part 280 Architecture
Under 40 CFR § 280.12 , an Underground Storage Tank (UST) is legally defined as:
"Any one or combination of tanks (including connected underground pipes) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground." +-----------------------------------------------------------------------------+
- | UST STATUTORY EXCLUSIONS |
- | |
- | [NOT REGULATED AS USTs UNDER 40 CFR PART 280]: |
- | 1. Farm or residential tanks of 1,100 gallons or less capacity used for |
- | storing motor fuel for noncommercial purposes. |
- | 2. Tanks used for storing heating oil for consumptive use on the premises |
- | where stored. |
- | 3. Septic tanks and public stormwater / wastewater collection systems. |
- | 4. Flow-through process tanks and surface impoundments. |
- | 5. Liquid petroleum pipeline facilities regulated under pipeline safety. |
- | 6. Storage tanks situated in an underground area (e.g., basement, cellar, |
- | vault, or tunnel) if the tank is situated upon or above the surface |
- | of the floor. |
- +-----------------------------------------------------------------------------+
- 5. UST Technical Controls: Spill, Overfill, and Cathodic Protection Systems
The 2015 Revised EPA UST Regulations established strict engineering mandates for release prevention: +-----------------------------------------------------------------------------+
- | UST SPILL & OVERFILL PREVENTION DEVICES |
- | |
- | [SPILL BUCKET (Catchment Basin)] |
- | - Minimum 5-gallon liquid capacity installed at the fill pipe. |
- | - Tested for liquid tightness every 3 years (hydrostatic or vacuum test). |
- | |
- | [OVERFILL PREVENTION OPTIONS (Choose at least one)]: |
- | - Automatic Shutoff Device (Flapper Valve): Shuts off flow at 95% tank |
- | capacity. |
- | - High-Level Alarm: Sounds an audible/visual alert at 90% tank capacity. |
- | - Ball Float Vent Valve: Restricts vent line flow at 90% capacity (note: |
- | prohibited on new installations / suction piping post-2015). |
- +-----------------------------------------------------------------------------+
- Cathodic Protection Systems (40 CFR § 280.31)
Buried steel tanks and metal piping undergo electrochemical oxidation (rusting) in the presence of soil moisture and electrolytes. UST systems must be protected using one of two cathodic protection methods:
Galvanic (Sacrificial Anode) System: Sacrificial blocks of zinc or magnesium with higher electrochemical potential are connected to the steel structure, corroding preferentially to protect the tank.
Impressed Current Cathodic Protection (ICCP): An external direct current (DC) power source (rectifier) delivers protective electrons to the buried steel through inert anode groundbeds.
Cathodic Maintenance & Testing Schedules:
60-Day Rectifier Logging: ICCP rectifiers must be inspected and recorded every 60 days to verify normal DC voltage and amperage output.
3-Year System Testing: All cathodic protection systems (galvanic and impressed current) must be tested by a qualified cathodic protection tester every 3 years to verify protective negative potential (≤ -850 mV relative to a saturated copper/copper sulfate electrode [CSE]). Records of the last two tests must be kept.
6. UST Release Detection Methods & Line Leak Testing
Tanks and pressurized piping must undergo continuous or monthly release detection capable of detecting releases of 0.2 gallons per hour (gph) with a 95% probability of detection (Pd) and a 5% probability of false alarm (Pfa).
Method Technology & Mechanism Regulatory Threshold & Frequency
Interstitial Monitoring Electronic liquid sensors or vacuum/pressure monitoring between inner and outer tank/piping walls Mandatory for all tanks and piping installed after April 2016 ; continuous or monthly check.
Automatic Tank Gauging (ATG) Magnetostrictive or ultrasonic probes in tank calculating inventory, temperature, and volume change Conducts static leak test detecting 0.2 gph monthly ; or continuous in-tank leak detection (CITLD).
Statistical Inventory Reconciliation (SIR) Computer analysis of daily inputs, sales, and stick measurements using advanced statistical models Analyzed monthly; must detect 0.2 gph leak rate.
Electronic Line Leak Detector (ELLD) In-line pressure transducers on pressurized product piping Shuts off pump or restricts flow when leak of 3.0 gph at 10 psi is detected within 1 hour ; tested annually.
7. UST Temporary & Permanent Closure Protocols (40 CFR Part 280 Subpart G)
When a UST system is taken out of service, the owner/operator must adhere to strict closure timelines: +-----------------------------------------------------------------------------+
- | UST CLOSURE PATHWAY DECISION |
- | |
- | [TEMPORARY CLOSURE (< 3 Months)] |
- | - Continue operation of corrosion protection (maintain rectifier). |
- | - Continue release detection (unless tank is emptied to < 1 inch liquid). |
- | | |
- | v |
- | [TEMPORARY CLOSURE (3 - 12 Months)] |
- | - Leave vent lines open and functioning. |
- | - Cap and secure all other lines, pumps, manways, and fill pipes. |
- | | |
- | v |
- | [PERMANENT CLOSURE (> 12 Months)] |
- | - Notify implementing agency at least 30 days prior to closure. |
- | - Perform Comprehensive Site Assessment (soil & groundwater sampling). |
- | - Remove all liquids and accumulated sludges. |
- | - Physical Removal from ground OR In-Place Closure (filling tank with an |
- | inert solid material such as sand, concrete slurry, or cellular foam). |
- +-----------------------------------------------------------------------------+