State Water Resources Control Board

This letter clarifies the exemption of farm tanks and home heating oil tanks from state underground storage tank (UST) regulations. The following topics are discussed:

a. "Farm tank" means any one tank or a combination of manifolded tanks that 1) are located on a farm; and 2) hold no more than 1,100 gallons of motor vehicle fuel [MVF] which are used primarily for agricultural purposes and are not held for resale.

b. "Heating oil tank" means a tank located on a farm or at a personal residence and which holds no more than 1,100 gallons of home heating oil which is used consumptively at the premises where the tank is located.

2) Examples of Exempt Tanks (Section 2621(a) CCR)

All farm tanks and home heating oil tanks which meet the criteria specified in (a) or (b) above are exempt from state UST regulations. Consequently, installation, operating, and closure requirements do not apply to these tanks. For example, home heating oil tanks at homes which have converted to electricity or natural gas for heating purposes are exempt as long as they are not used for a non-exempt purpose. Also, farm tanks with a capacity of 1,100 gallons or less which store motor vehicle fuel for agricultural purposes are exempt as long as they are not used for a non-exempt purpose. However, the State and Regional Water Board's authority, under Section 13304 of the California Water Code, to require clean up or other pollution prevention measures remains unimpaired if releases from such tanks threaten water quality.

3) Conditions Under Which an Exempt Tank Becomes a Regulated Tank
(Section 2621(c) CCR)

An exempt UST may become regulated if a condition allowing its exemption changes. A change in exemption status can come from any of the following:

a. Property loses its status as a "farm". According to Food and Agricultural Code Sections 52262. and 54004, a farm is a place of agricultural production which has annual sales of agricultural products of $1,000 or more. Agricultural products include any horticultural, viticultural, forestry, dairy, livestock, poultry, bee or farm product. Therefore, if a farm's annual sales of agricultural products falls below $1,000, or the farm crop is not included in the definition of "agricultural production," the property no longer retains its "farm" status. Therefore, tanks located on that property which are used after the property loses its farm status become subject to regulation.

b. Property loses its status as a "personal residence". If the residence has a home heating oil tank and the property is changed for commercial or other non-residential purposes (other than a farm), the tank used after the change becomes subject to regulation.

c. The tank contents change from MVF or home heating oil. MVF's are defined, for purposes of the UST program, as petroleum products which are intended to be used primarily to fuel motor vehicles or engines. Heating oil is a petroleum product which is used for heating.

d. The use of a farm or home heating oil tank changes to a use which is not exempt. If the use of a tank which contains MVF changes to something other than "primarily for agricultural purposes and not for resale," then the tank becomes subject to regulation. Likewise, if the use of a tank which contains home heating oil, changes to something other than "for consumptive use on the premises where stored," then the tank becomes subject to regulation.

4) Tank Owner Responsibilities if an Exempt Tank Becomes a Regulated Tank (Section 2621(c) CCR)

The owners of all tanks which are exempted by Section 25281(x)(1)(A) and (x)(1)(B) of the Health and Safety Code (H&SC) and which lose their exemption by virtue of a change to a regulated use, must either obtain a valid operating permit or close the tank in accordance with Chapter 6.7 H&SC and any applicable local agency requirements.

UST Program - Local Guidance (LG) 109-1