This document discusses repairs, replacements, installations, and secondary containment requirements for underground storage tanks (USTs). It also covers changing a UST system to biodiesel. Key points include: repairs must follow manufacturer specifications and codes; metal pipes cannot be repaired and must be replaced; secondary containment is required for all new and replaced tanks/piping after 2012; and changing an existing UST to 100% biodiesel requires notifying ECY but UST laws do not apply.

1. Repair - Replacement Improvement - Modifications

2. Repairs
Repairing tank liner or fixing a hole in the tank or spill bucket
 A tank system must be repaired to prevent and detect releases due to
structural failure or corrosion
 Repairs must be performed in accordance with manufacturer’s
specifications and national code of practice
 Metal pipe sections and fittings cannot be repaired and must be replaced
 A tank that has previously been repaired or upgraded using the interior
lining method may be repaired only if structurally sound
 There are repairs that will require an Ecology Retrofit/Repair checklist
this and other forms may be found on ECY website under Publications/
Forms.
(SEE UNDERGROUND STORAGE TANK INFORMATION/CHECKLIST IN PACKET)

3. Repairs/Replacements
 Tanks
– Get written documentation from manufacturers for tank
modifications
– Perform a tank tightness test after completion of repair and report
any test failures
 Piping
– Perform a line tightness test after completion of repair and report any
test failures
 Corrosion Protection
– Must provide protection to all metal components that contain
regulated substances.
– If the system fails an evaluation it must be repaired and tested at the
time of repair, then re-tested within 1-6 months following the repair.
 Spill and Overfill
– Spill and overfill equipment must be installed to comply with
recommended practices of the UST systems

4. Installations
Installation of tanks and piping
 Tanks and underground piping must be installed by ICC certified UST
vendor
 Tanks and piping must be made of or lined with materials that are
compatible with the substance stored in the tank system
 All tank systems installed must meet performance standards:
– Spill and overfill prevention equipment and requirements
– Corrosion protection performance standards
– Release detection performance standards
– Installation by licensed personnel

5. Secondary Containment for
Tanks and Piping
What is Secondary Containment?
 A single-walled tank is the first or primary containment. Secondary is
enclosing an UST within a second wall. Leaks can be contained and
detected quickly before harming the environment.
When is Secondary Containment required?
 Owners and operators shall install secondary containment and interstitial
monitoring (between the walls) for all (including petroleum) new and
replaced tanks and piping after October 1, 2012.
 Owners and operators must replace entire piping run when 50 percent or
more of piping is removed and other piping is installed.
 Owners and operators will install under dispenser containment for all new
dispenser systems.

6. Changing to Biodiesel
Biodiesel
 Cleaner-burning replacement fuel
 Made from vegetable oil
 Using biodiesel in a conventional diesel engine substantially
reduces emissions of unburned hydrocarbons, carbon
monoxide, sulfates, and particulate matter
 Less toxic to the environment than petroleum-based diesel
 Biodegrades much faster

7. Biodiesel
 If biodiesel is blended with petroleum diesel, another
petroleum product, or a hazardous substance, Washington’s
UST rule must be followed
 100% biodiesel contains no petroleum-based products or
hazardous substances, therefore state UST laws do not apply
 If you change a UST to 100% biodiesel notify the ECY of the change in
service, perform a site assessment by a certified assessor, once submitted the tank
status will change and tank fees will not apply