Underground storage tank (UST)

EPA defines a UST system as a tank and any underground piping connected to it that has at least 10 percent of its combined volume underground. Federal UST rules apply to tanks storing petroleum or certain hazardous substances.

Old tanks are a common surprise on commercial and industrial lots in Missouri. They may sit under former gas stations, shops, farms or factories, and some have been forgotten for decades. A leaking tank can contaminate soil and groundwater.

Missouri DNR sets a firm step for closing one. Permanent closure requires filing a Closure Notice for Underground Storage Tanks with the department at least 30 days before closure activities, and DNR should approve it before work begins.

Plan for the whole job: notice, tank cleaning and removal, soil sampling, and disposal. If sampling finds contamination, soil remediation may follow, and residues may count as hazardous waste. Hire a crew that handles the paperwork and the field work together.