Pennsylvania DEPAboveground Storage Tank Update

2016 NISTM PA CONFERENCE

Camp Hill, PA

April 14, 2016

Updates

• UL-142 Closed Top Dike Tank Inspections

• Double-walled ASTs: Spill and Overfill Protection

• Flexible Connections

• Emergency Vents

• Internal Linings

• Emergency Containment vs. Secondary Containment in PA

PADEP Aboveground Storage Tank Update

UL-142 Closed Top Dike Tank Inspections

UL-142 Closed Top Dike Tank Inspections

UL-142 Closed Top Dike Tank Inspections

What does it look like in there?

*Photographs courtesy of Steel Tank Institute

UL-142 Closed Top Dike Tank Inspections

How about the removable type rain shields?

UL-142 Closed Top Dike Tank Inspections

What about spill and overfill protection on the tanks with rain shields? See double walled ASTs.

Small ASTs (≤ 21,000-gallons in capacity)

Secondary (outer) wall may meet emergency and

secondary containment requirements if equipped with

spill and overfill protection controls. There are usually

four spill and overfill devices required to meet this.

Double Walled Aboveground Storage Tanks

Spill and Overfill Controls – spill containment bucket

Double Walled Aboveground Storage Tanks

Spill and Overfill Controls – overfill alarm or monitoring

gauge and shut down procedure

Double Walled Aboveground Storage Tanks

Spill and Overfill Controls – block valves on product

lines

Double Walled Aboveground Storage Tanks

Nodular iron or steel. No brass or low melting point materials.

Spill and Overfill Controls – solenoid valve or anti-

siphon device (product piping is positioned or drops

below maximum liquid level)

Double Walled Aboveground Storage Tanks

Double Walled Aboveground Storage Tanks

AST Flexible Connectors

Perhaps installing a flex connector immediately downstream of the ball valve would have prevented this tank from cracking.

When to consider:

• Connections made from a poly tank shell (lower third of

sidewall), and some FRP tanks where connections are made to

rigid piping.

• Rigid piping connections subject to vibration from pumps,

engines, etc.

• Fulcrums that could crack the tank

• Hinge points that stress the tank

AST Flexible connectors

Do’s

• Proper selection

– Flexible hoses (up to 3 to 4 feet in length)

– Expansion Joints (about 6 inches long)

– Check compatibility/UL rating for ABOVEGROUND applications

• Know the specific parameters

– Axial, lateral, and differential movements (min. and max. distance)

• Always read the installation manual

AST Flexible connectors

Don’ts:

• Improper support – always place support after the flexible

connector to allow tank to move

• Improper location – needs to installed after a block valve on

the lower third of shell

• Using a flexible connector to correct piping misalignment

– This can damage a joint and restrict the flexible connector’s ability to

move with the tank

AST Flexible connectors

Emergency Venting

8”

5Emergency Venting

Common Problems

- Inadequate design – not sized properly or just bad math.

4” 4”

Emergency Venting

Common Problems - shear pin broke

Emergency Venting

Common Problems – manway lids bolted down won’t lift under excess pressure

Emergency Venting

Common Problems – frangible roof may not work on some smaller diameter (<50 feet) ASTs.

*Refer to API 650 (Section 5.10.2.6) for design considerations

Emergency Venting

Common Problems – Double walled ASTs with no emergency vent for the secondary tank (F&C liquids)

Why?

• Corrosion protection

– Alternative fuel blends

– MIC

• Compatibility

– Tank isn’t compatible with

substance stored, but lining

is, and protects AST.

• Product purity

– Discoloration caused by Fe

Interior Lining and Coatings

• Must be applied and repaired

by PADEP-certified tank liner

(TL)

• Designed in accordance with

API 652 or associations such

as NACE.

• Coatings must be bonded

firmly to the tank surface,

and surfaces must be

prepared according to specs.

Interior Lining and Coatings

• Inspected by PADEP

AST Inspector at

installation and repair

– Holiday (spark test)

– Film thickness checked

when cured

– Adherence test

Interior Lining and Coatings

• Defects are repaired

by TL and re-

inspected by PADEP-

certified AST

inspector, prior to

placing tank back into

service.

Interior Lining and Coatings

Lining Inspections

Must occur at least

every 10 years or as

warranted or

recommended by

the manufacturer or

design engineer.

Interior Lining and Coatings

Emergency Containment = “the tub around the tank”

• dike floor and walls

• permeability requirements differ for large and small ASTs

Secondary Containment = impermeable layer below the

tank with space for release detection (RPB)

• impermeable layer below the tank and space for release detection

• required for all small ASTs and new large ASTs. Existing ASTs without

secondary containment, without CP and/or internal lining must be leak tested

during every in-service integrity inspection until upgraded

Containment - Emergency vs. Secondary

Large ASTs (> 21,000-gallons in capacity)

• Capacity: Must be greater than or equal to 110% the volume of

single largest AST within the containment structure

• Permeability rate: must be less than 1.0 X 10-6 cm/sec for newly

installed ASTs, replacement structures and existing ASTs; and be of

sufficient thickness to prevent the released substance from

penetrating the containment structure for a minimum of 72 hours,

and until the release can be detected and recovered.

Emergency Containment

Large ASTs (> 21,000-gallons in capacity)

Existing ASTs with emergency containment permeability rates >

1.0 X 10-6 cm/sec, either upgrade, or verification by a PE that the

structure, coupled with the tank monitoring program and

response plan, is capable of detecting and recovering a release…

Emergency Containment

Small ASTs (≤ 21,000-gallons in capacity)

• Must be sufficiently impermeable to contain any

potential release for a minimum of 72 hours and

until the release can be detected and fully recovered

in an expeditious manner.

– Monitoring and Response Plan? Emergency containment

permeability rate?

Emergency Containment

Large ASTs(> 21,000-gallons in capacity)

• Must be installed on a new tank at installation and

on an existing tank at reconstruction, relocation or

when the tank floor is replaced

– Permeability must be less than 1.0 X 10-7 cm/sec

Secondary Containment

Large ASTs(> 21,000-gallons in capacity)

• Existing tanks without secondary containment that

do not have cathodic protection or an internal lining

must be leak tested at every in-service integrity

inspection, until the tank is upgraded.

Secondary Containment

Small ASTs (≤ 21,000-gallons in capacity)

• Need to be installed with secondary containment in

or under tank bottom to satisfy leak detection

requirements.

– A method of leak detection shall be in use and monitored

monthly. A documented visual assessment is sufficient.

Secondary Containment

Small ASTs (≤ 21,000-gallons in capacity)

Secondary (outer) wall may meet emergency and

secondary containment requirements if equipped with

spill and overfill protection controls. There are usually

four spill and overfill devices required to meet this.

Double Walled Aboveground Storage Tanks

PADEP Resources:Title 25, Pa Code, Chapter 245. Administration of the Storage Tank and Spill Prevention

Program. January 7, 2012.

Storage Tank and Spill Prevention Act. Act of Jul. 6, 1989, P. L. 169, No. 32

“Verification of Emergency Containment Structures for Aboveground Storage Tanks”. 263-0900-022. September 8, 2012.

“Permeability of Secondary and Emergency Containment”. 263-3300-002. September 8, 2012.

“Guidelines for the Development and Implementation of Environmental Emergency Response Plans”. 400-2200-001. August 6, 2005.

Guidance

Questions?

Any Questions?

Chad Clancy AST Unit Supervisor

Bureau of Environmental Cleanup and BrownfieldsRachel Carson State Office Building

PO Box 8763Harrisburg, PA 17105-8763

717.772.5830cclancy@pa.gov