Current through Register Vol. 48, No. 38, September 20, 2024
In all situations, no matter which method is used to assess
the integrity of the tank prior to addition of cathodic protection, the
cathodic protection system being field installed in Illinois must be designed
by a corrosion expert who is NACE certified in cathodic protection design or by
a Licensed Professional Engineer with the state who has certification or
licensing that includes education and experience in corrosion control of buried
or submerged metal piping systems and metal tanks. Those contractors installing
the cathodic protection systems in Illinois must be licensed as cathodic
protection installers. These contractors must successfully pass the
International Code Council (ICC) certification exam module for cathodic
protection.
a) Cathodic Protection. A
tank may be upgraded by cathodic protection if the cathodic protection system
meets the requirements of 41 Ill. Adm. Code 172, 174, 175, 176 and 177, and the
integrity of the tank is ensured using one of the following methods:
1) To be suitable for upgrading by cathodic
protection, the integrity of the tank must be ensured by one of the following
methods:
A) For tanks installed for less than
10 years, one of the following requirements applies:
i) The tank is internally inspected and
assessed to ensure that the tank is structurally sound and free of corrosion
holes prior to installing the cathodic protection system. Two tank precision
tests must also be conducted that meet the requirements of OSFM precision tank
testing. The first precision test shall be conducted prior to the installation
of the cathodic protection system. The second precision test shall be conducted
between 3 and 6 months following the first operation of the installed cathodic
protection system. Both precision tests must indicate tightness of the tanks;
or
ii) Use of alternative methods
approved by OSFM. These acceptable alternative methods are indicated in
subsection (a)(1)(B) for tanks that are over 10 years old.
B) For tanks installed for more than 10
years, the following methods apply:
i) An
invasive inspection method that ensures the tank is internally inspected and
assessed to ensure that the tank is structurally sound and free of corrosion
holes prior to installing the cathodic system. The internal inspection
procedures shall follow the requirements of NLPA 631;
ii) An invasive remote video camera test is
conducted prior to the installation of the cathodic protection system. The
video system must be capable of recording a video survey of the interior
surface of the tank with a suitable lighting source; or
iii) The tanks are assessed for corrosion
holes by other methods determined by OSFM, to prevent releases in a manner that
is no less protective of human health and the environment than subsections
(a)(1)(B)(i) and (ii).
2) OSFM requires a tank integrity assessment
even if both cathodic protection and interior lining systems are being
installed. If the cathodic protection and interior lining are installed at the
same time, only one approved integrity assessment is required. Even if both
systems have been installed, OSFM requires routine inspection and maintenance
of both systems to continue.
3)
USTs equipped with both interior lining and cathodic protection (sacrificial
anodes or impressed current).
A) The following
maintenance procedures shall apply:
i)
Sacrificial anodes must be tested according to the requirements of subsection
(f).
ii) Impressed current records
of operation must be recorded every 30 days and records kept on site for 2
years. The system must be tested annually according to the requirements of
subsection (f).
iii) As of
September 1, 2010, some facilities may exist that had been previously granted
an OSFM waiver for the UST lining maintenance requirements based upon original
field notes from the initial lining, of an invasive method of initial tank
integrity assessment verifying that there were no holes in the tank. For these
systems, only the external cathodic protection system must be maintained and
tested. This is contingent upon the original field notes being available, and a
letter from OSFM existing from that time to verify the waiver was
granted.
B) For those
USTs where a non-invasive tank integrity assessment method was used or if there
were any holes present in the tank, regular interior lining inspections must
continue as described in Section
175.500.
b) ACT-100 Tanks Installed with
Sacrificial Anodes. Owners of ACT-100 tanks meeting STI F894, incorporated by
reference in 41 Ill. Adm. Code
174.210, and able to produce
ACT-100 warranty papers may choose the steel-FRP composite design as a sole
method of corrosion protection instead of maintaining the sacrificial
anodes.
c) Upgrades to Combine
Internal Lining with Cathodic Protection. Some tanks may exist that were
previously upgraded by both internal lining and cathodic protection. Such tanks
were to be inspected for both the internal lining and the cathodic protection
within 90 days after the upgrade and must continue to be maintained by regular
inspections of the cathodic protection system pursuant to the requirements of
this Section.
d) Piping Corrosion
Protection Requirements. All UST metal product piping that is in contact with
backfill, ground or water shall be cathodically protected. All metal risers,
vents and fills in contact with backfill, ground or water shall be
dielectrically coated. Shrink-wrap or boots are not acceptable as a form of
cathodic protection in a water environment.
e) Wiring of all associated electrical
equipment shall conform to the requirements of Section
175.425 and shall also conform
to the following requirements:
1) All wiring
that is connected to any anode of an impressed current system shall be no less
than No. 10 stranded, with jacketing that is suitable for direct burial and
that is petroleum or hazard resistant for the product conveyed. Such jacketing
is to have a thickness sufficient to cause the wiring to have a diameter of at
least
5/16 inch.
Systems existing prior to May 1, 2003 may remain.
2) All wiring connected to any anode of a
sacrificial anode system shall be suitable for direct burial and shall be
resistant to petroleum and/or hazardous substances.
3) All structural lead wiring of any cathodic
protection system shall be suitable for direct burial and shall be petroleum
and/or hazard resistant.
4) For
installation of cathodic protection systems to facilities existing prior to May
1, 2003, existing anode wiring may be replaced into existing pavement saw-cuts,
provided that the following conditions are met:
A) No part of the wiring is less than one
inch below the finished pavement surface, and provided that the portion of the
saw-cut groove above the wiring is filled with a combination of at least 3/8
inch of backer rod and at least 1/2 inch of self-leveling caulk suitable as a
concrete filler.
B) Structure lead
wiring of impressed current systems shall consist of at least 2 separate leads.
Such leads running from the junction box or rectifier to the UST structures
must be in separate saw-cuts, jumpering from one UST structure to the next. One
lead shall connect to the first structure to be protected and continue on to
all structures in the UST. The second lead will connect to the last structure
to be protected. Such loop is to ensure that if one lead were to become cut or
disconnected, the other lead would ensure the continued connection of the UST
structures and the junction box or rectifier.
C) All wiring from anodes shall terminate and
be identified (as to location per approved site plan), in strategically located
junction boxes, placed in and around the protected field. This will facilitate
the testing of each anode.
D) Any
additions or extensions done to the existing network must conform to Section
175.425(a).
5) Beginning May 1, 2003 for
installation of cathodic protection systems, all wiring running outside of
manholes or sumps shall be located at least 12 inches below the finished grade
and installed in conduit approved for petroleum and/or hazardous
installations.
f)
Operation and Maintenance of Cathodic Protection. Owners or operators of steel
USTs with corrosion protection shall comply with the following requirements to
ensure that releases due to corrosion are prevented for as long as the UST is
used to store regulated substances:
1) All
corrosion protection systems shall be operated and maintained to continuously
provide corrosion protection to the metal components of that portion of the
tank and piping that routinely contain regulated substances and are in contact
with the ground, backfill or water.
2) All USTs equipped with sacrificial anode
or impressed current cathodic protection systems shall be regularly tested and
inspected for proper operation, including when being first put into operation,
by an OSFM-licensed contractor who has licensure in the cathodic protection
module, using an employee who has successfully passed the International Code
Council (ICC) certification exam module for cathodic protection. Such testing
shall be in accordance with the following requirements:
A) Frequency.
i) Sacrificial anodes shall be tested every 3
years as long as testing results are -850 millivolts or a higher negative
number. In the event testing results do not meet the -850 millivolt
requirement, the anodes shall be replaced. This requirement applies to all
sacrificial anodes, including wristband and spike anodes.
ii) Impressed current systems shall be tested
annually as long as testing results are -850 millivolts or a higher negative
number. In the event testing results do not meet the -850 millivolt
requirement, the impressed current system shall be repaired or upgraded as
needed to meet the -850 millivolt requirement.
iii) All cathodic protection systems shall be
re-tested no less than 24 weeks and no more than 28 weeks from the date of
installation or repairs.
B) Inspection Criteria. The criteria that are
used to determine that cathodic protection is adequate as required by this
subsection (f)(2)(B) shall be in accordance with NACE SP0285 and SP0169,
incorporated by reference in 41 Ill. Adm. Code 174.210. Subject to the
technical applicability of these criteria given actual site conditions, one or
more of the following criteria shall apply for adequacy of cathodic protection.
Cathodic protection shall be repaired or replaced if it fails to meet the
standards provided in this subsection (f)(2)(B).
i) A negative (cathodic) potential of -850
millivolts or a higher negative number with cathodic protection applied. This
potential is measured with respect to a saturated copper/copper sulfate
reference electrode contacting the electrolyte.
ii) A minimum 100 millivolt of cathodic
polarization between the structure and a saturated copper/copper sulfate
reference electrode contacting the electrolyte. Such polarization shall be
determined from the taking of a valid "instant-off" test, that, for each
testing point, determines the voltage reading at the second drop in voltage
following the interruption in cathodic protection being applied, and determines
if the voltage reading is at least 100 millivolts higher than either the native
reading or any other reading after the structure has had time to depolarize
with no cathodic protection applied.
3) USTs with impressed current cathodic
protection systems shall be inspected every 30 days, to ensure the equipment is
running properly.
4) For USTs using
cathodic protection, records of the operation of the cathodic protection shall
be maintained to demonstrate compliance with the performance standards in this
Section. These records shall provide the following:
A) The results of 6-month testing for
sacrificial anode systems must be maintained on site for 2 years;
B) All records from the last 2 cathodic
protection total system tests by a qualified cathodic protection tester
pursuant to a 3-year cycle must be maintained on site;
C) Impressed current systems must be
inspected every 30 days and reports or a log maintained that shows date of
inspection, initials of inspector, hour, volt and amp readings, and power on
verification. A minimum of 2 years of records shall be kept on site;
and
D) The records from the
impressed current annual test conducted by an OSFM licensed contractor shall be
kept on site for 2 years.
5) Alternative methods of corrosion
protection may be used if approved in writing by OSFM, provided they are no
less protective of human health or the environment.
