|
State Water Resources Control B and Page 2 of 6
<br /> 10
<br /> Limited Specialty/Protective Coating(C-61/D51)*
<br /> Painting and Decorating(C-33)
<br /> Plumbing Contractor(C-36)
<br /> *This license is no longer issued,but valid licenses may still exist.
<br /> The Hazardous Substance Removal Certification issued by CSLB is required for installation,repair,upgrading and/or removal of
<br /> an underground storage tank.Upgrading includes installation of a bladder system or application of interior lining.
<br /> CSLB does not require contractors to possess the hazardous substance removal certification to line tanks.
<br /> See LG 48-5 for more information concerning licensing requirements or contact CSLB at 916-255-3900 or at their website(see
<br /> above).
<br /> WHICH TANKS MAY BE LINED?
<br /> Tank lining may be performed only on tanks storing motor vehicle fuel.Lining may be performed as a preventive measure to satisfy the
<br /> December 1998 upgrade requirements for steel tanks. However,single-walled fiberglass tanks storing motor vehicle fuel do not require
<br /> lining or replacement by 1998.Likewise,single-walled steel tanks which store motor vehicle fuel and are clad on the outside with
<br /> fiberglass or another non-corrosive material do not require lining or replacement.
<br /> IS SOIL SAMPLING REQUIRED PRIOR TO LINING?
<br /> This is left up to the local agency. In accordance with sections 25296(c)_Health and-Safety Code,a continuous vapor or ground water
<br /> monitoring system must be installed adjacent to a single-walled tank if the tank that is proposed to be interior lined had previously leaked.
<br /> The purpose of the continuous monitoring system is to differentiate between any residual contamination from the prior leak and any future
<br /> failure of the operational integrity of the lining.There is no requirement to install this monitoring system where it can be determined to the
<br /> satisfaction of the local agency that the tank itself has not previously leaked.
<br /> The law gives broad authority to the local agencies to adopt more stringent requirements(Section_25299.2_Health_.and_Safety Code)
<br /> including the determination of whether a tank has previously leaked.In the past,some local agencies have required soil samples at each
<br /> end of the tank.Others have trusted monitoring results such as the most recent tank tightness test.Since a tank test result can only
<br /> determine whether a tank is leaking at the time the test is performed,reviewing inventory reconciliation records over long periods may be
<br /> beneficial.And finally,some local agencies consider the inspection results from the special inspector who enters the tank and performs
<br /> evaluations on the tank shell when determining whether the tank itself has previously leaked.
<br /> If the local agency chooses to require soil samples to determine whether the tank itself has previously leaked,then only samples at
<br /> locations adjacent to the tank are necessary to verify whether the tank itself has leaked(as opposed to piping leaks,dispenser leaks,
<br /> spills,overfills,etc.).Therefore,it is not necessary to take soil samples underneath dispensers or along lengthy piping runs to determine
<br /> whether a continuous vapor or ground water monitoring system must be installed during the lining process.
<br /> CAN TANKS THAT HAVE PREVIOUSLY LEAKED BE LINED?
<br /> YES.Section25296(a)_Health and _Safety_Code allows a tank to be repaired by lining.Lining may be performed to repair a steel,
<br /> fiberglass,or clad tank that has minimal structural or corrosion problems.However,a tank that was previously lined may not be lined a
<br /> second time if it leaks. In other words,relining of a previously lined tank that has leaked is not allowed so as to avoid repeated repair of a
<br /> tank that is fundamentally unsound.
<br /> CAN TANKS LOCATED AT CONTAMINATED SITES BE LINED?
<br /> This will depend upon the results of a soil and ground water investigation.If any of the conditions in section 2724 CCR are present,then a
<br /> complete soil and ground water investigation of the entire site must be completed to determine the effects of contamination.
<br /> Consequently,conditions may exist that require soil and ground water investigations involving sampling in order to assess the effects of
<br /> contamination,if any.If there is known contamination,regardless of the source,soil and/or ground water sampling is required to conduct
<br /> a site assessment in accordance with Article 11_CCR.With concurrence from the regulatory agency overseeing cleanup,a tank that has
<br /> leaked may be repaired by lining if the contamination can be remediated and mitigated with the tanks in place.On the other hand,if the
<br /> site assessment indicates that tank removal is necessary to remediate or mitigate potential adverse affects of the unauthorized release,
<br /> then tank lining should not be allowed.
<br /> WHAT TESTS ARE REQUIRED PRIOR TO TANK LINING?
<br /> Before a tank may be lined,a special inspector(i.e.,qualified professional engineer)must certify in writing that the tank is suitable for
<br /> lining and continued use.Article_6 does not require the engineer to be financially independent of the tank owner or lining company.After
<br /> the tank is emptied,cleaned,purged,and tested by ultrasound for thickness,the engineer must enter the tank and perform several tests
<br /> on the tank's interior.For steel tanks,the tank must be cleaned and sandblasted to white metal.The engineer must perform a visual
<br /> inspection in which he counts the number of holes,splits,perforations,and other defects in order to certify that the tank is structurally
<br /> sound.For fiberglass tanks,the engineer must perform a visual inspection and take interior diameter measurements to determine if there
<br /> is structural,tension,or compression problems.
<br /> If the engineer certifies that the tank is suitable for lining and continued use,all holes,splits,defects,and thin areas must be reinforced
<br /> before application of the lining.Materials used to reinforce or plug holes must be compatible with the substance that will be stored.Striker
<br /> plates must be installed beneath all tank openings that could be used for manual dipsticking.
<br /> WHAT TESTS ARE REQUIRED IMMEDIATELY FOLLOWING LINING?
<br /> After the tank is lined,but before it is returned to service,a qualified coatings expert,who is independent of the tank lining company and
<br /> http://www.waterboards.ca.gov/water issues/programs/ust/leak_prevention/lgs/136_I.shtml 2/17/2010
<br />
|