Per California Building Code, Title 24, tanks installed in "essential facilities" (eg Police and Highway Patrol buildings, airport control towers, most hospitals) and fire suppression tanks require higher seismic and wind load standards of construction. For example, the Seismic Importance Factor increases from the standard 1.0 to 1.5. In most cases our standard Zone 4 supports will need upgrading at extra cost.

They can be designed by Hanson Tank but if a P.E. sign-off is requested the fee is extra. There are several other categories of structures that require an Importance Factor higher than a 1.0, For example those containing toxic or explosive substances.

It is our customer’s responsibility to let us know if these enhanced Seismic and Wind Load standards are necessary when the quote is requested but no later than before the drawing is approved. If we are not so advised, normal commercial Seismic standards are deemed to be acceptable. In any case, any and all extra costs are the customer’s responsibility. Of course they will be much higher if the tank is already in production and especially if it is already installed on the job.