COMPLIANCE INFO_2000-2009 - Laserfiche WebLink

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• 12' diameter tanks require: • ❑ 24" between adjacent tanks. ❑ 24' between tanks sides and ends, and the banks of the excavation. Unstable Excavations (all size tanks) yam/ Im Dia.. Dia. '24 %ulled A A A112 Tank Dia. 1/2 Tank Dia. 1/2 Tank Dia.% • Muck, bog, peat, swamp or landfill type areas where the soil is soft or in areas with expansive clay soils. • Have less than 750 lbs./sq. ft. cohesion per ASTM D 2166*. • Have ultimate bearing capacity less than 3500 lbs./sq. ft. ❑ Minimum 18" (24' preferred) between adjacent tanks. ❑ Excavation must allow a minimum of '/2 the tank di- ameter from ends and sides of tanks to excavation walls. •'Test Methods for Unconfined Compressive Strength of Cohesive Soil. • May require a reinforced concrete pad under tank. • Contact soils consultant for recommendations. • Filter fabric hole liner is recommended for soils (see sec- tion A6 for list and further requirements): ❑ With less than 250 lbs./sq.ft. cohesion or, ❑ With ultimate bearing capacity of less than 500 lbs./ sq. ft. A5. Burial Depth and Cover Excavation Depth • All tank holes must be deep enough to: ❑ Allow a minimum of 12" and a maximum of 24" required backfill bed over the hole bottom or con- crete pad. Pad Dimension • Paving must extend at least 12" beyond tank pe- rimeter in all directions. Maximum Burial Depth • UL Requirements specify that the depth ofcover must not exceed 7'. • ❑ For all size tanks. ❑ For both traffic and no traffic conditions. • For deeper burial depths, contact Tank Technical Sup- port. Phone number listed on page 2. Minimum Burial Depth No Traffic Load (4' thru 10' diameter tanks) • Tanks need a minimum cover of 24" backfill or • 12" of backfill plus 4" reinforced concrete.* • Consult local codes for minimum allowable burial depth. *When mechanical anchoring is required, refer to chart on page 6 for minimum burial depths. (12' diameter tanks) • Tanks need a minimum cover of 42" backfill or • 38" backfill plus 4" reinforced concrete. Minimum Burial Depth H-20 Traffic Loads (4' - 10' diameter tanks) • Tanks need a minimum cover depth of 36" backfill or • 18" of backfill plus 6" of reinforced concrete.* *When mechanical anchoring is required, refer to chart on page 6 for minimum burial depths. Note: • The reinforcements in the concrete traffic slab must be properly sized for job conditions and traffic loads to as- sure concrete surface pad integrity. (12' diameter tanks) • Tanks need a minimum cover of 38" backfill plus 6" of reinforced concrete. A6. Filter Fabric Why use filter fabric? • It prevents the migration of pea gravel with native soil. • It helps maintain the integrity and stability of backfill materials. 5