Testing Procedure forSecondary Containment Tanks

Wayne Geyer, STISWRCB Technical Symposium

Secondary Containment TestingSacramento, CA December 4, 2001

California Regulation SB 989

• CA Code 2637 requires existing secondarycontainment systems to be tested by January1, 2003 and every 36 months thereafter. Newsystems installed after January 1, 2001 mustbe tested at time of installation, 6 monthsafter installation and every 36 monthsthereafter.

• Continuous system using vacuum orhydrostatic need not be tested every 3 years

Existing Systems in Operation

• Secondary containment must be tested inaccordance with manufacturer’s guidelinesand standards.

• If not available, system must be tested usingan applicable method specified in anindustry code or engineering standard

• Alternatively, the local agency may approvethe test method

1984 STI Dual Wall Tank StandardUL 58 Type I Double Wall Tank

UL 58 Type II Double Wall TanksPopular in CA: 1980’s

UL 1746 Jacketed TanksCommon Since 1990

Code Requirements on Test ofSecondary Containment Systems• International Fire Code - Per NFPA 30• Uniform Fire Code - Per manufacturer’s

instructions• NFPA 30 - Interstitial space shall be tested

hydrostatically or with air at 3-5 psi or byvacuum at 5.3” Hg for one hour. Care shallbe taken to ensure the interstitial space isnot subject to excess vacuum or pressure.

Procedure

• Part 1: Test procedure for double wall andjacketed tanks NOT exposed to a watertable

• Part 2: Test procedure for double wall andjacketed tanks EXPOSED to a water table

• Both parts use NFPA 30 as its basis

• Maximum 7” Hg applied to interstice in allcases, with acceptable 1” Hg drop - tosatisfy NFPA’s 5.3” Hg criteria

Test Procedure

• Verify interstice is dry• Pre-test all gauges, valves, & pipe connections

• Attach vacuum pipe system to annular space• Do not allow any explosive fumes to enter pump• Apply 7” Hg, turn off pump

• Allow vacuum to stabilize (re-apply vacuum asneeded)

• Hold for 1 hour with < 1” Hg drop

ProcedureVariations

• High water table inconjunction with 7”Hg can buckle Type IIand Type I tanks withextended tank heads

• Reduce vacuumaccordingly

Water Table6’Above Tank

Bottom• Variable vacuum <

7” Hg applied thatcorresponds to watertable above tank top

• Twelve pages oftables provided toassist contractor withtest vacuum

SecondaryTank Water Table as measured from bottom of tank in "Inches" of depth

Diameter 64 65 66 67 68 69 70 71 72 73 74 75 7624 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd26 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd28 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd30 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd32 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd34 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd36 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd38 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd40 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd42 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd44 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd46 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd48 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd50 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd52 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd54 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd56 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd58 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd60 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd62 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd64 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd66 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd68 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd70 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 No Vac Reqd72 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 1.8 No Vac Reqd74 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 1.9 1.8 1.8 No Vac Reqd76 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.1 2.0 1.9 1.8 1.878 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.2 2.1 2.1 2.0 1.980 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.4 2.3 2.2 2.1 2.182 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.5 2.4 2.4 2.3 2.284 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.7 2.6 2.5 2.4 2.486 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.8 2.7 2.7 2.6 2.588 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 2.9 2.9 2.8 2.7 2.790 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.1 3.0 2.9 2.9 2.892 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.2 3.2 3.1 3.0 2.994 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.4 3.3 3.2 3.2 3.196 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.5 3.5 3.4 3.3 3.298 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.7 3.6 3.5 3.5 3.4100 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 3.8 3.8 3.7 3.6 3.5102 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.0 3.9 3.8 3.8 3.7104 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.1 4.1 4.0 3.9 3.8106 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.3 4.2 4.1 4.1 4.0108 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.4 4.3 4.3 4.2 4.1110 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.6 4.5 4.4 4.3 4.3112 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.7 4.6 4.6 4.5 4.4114 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 4.9 4.8 4.7 4.6 4.6116 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.0 4.9 4.9 4.8 4.7118 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.2 5.1 5.0 4.9 4.9120 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.3 5.2 5.2 5.1 5.0122 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.5 5.4 5.3 5.2 5.2124 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.6 5.5 5.5 5.4 5.3126 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.7 5.7 5.6 5.5 5.5128 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 5.9 5.8 5.7 5.7 5.6130 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.0 6.0 5.9 5.8 5.7132 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.2 6.1 6.0 6.0 5.9134 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.3 6.3 6.2 6.1 6.0136 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.5 6.4 6.3 6.3 6.2138 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.6 6.6 6.5 6.4 6.3140 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.8 6.7 6.6 6.6 6.5142 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.9 6.9 6.8 6.7 6.6144 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.1 7.0 6.9 6.9 6.8146 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.2 7.1 7.1 7.0 6.9148 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.4 7.3 7.2 7.1 7.1

Water Table Above Tank Top

• No Further Test is Required as HydrostaticHead Fulfills Need to Verify Tightness ofContainment

• Additional Vacuum Adds Risk of Damageto Type II Double Wall Tank

Other Features

• Safety requirements• Conversion Factors

• Examples• Record-keeping Form

ConstructionMethods

ProvidingAccess toInterstice

Subject to Future Revisions

SimplifyProcedure to TestType I DoubleWall andJacketed Tanks,regardless ofwater table