Cal. Health & Safety Code § 79550

Any person subject to a removal or remedial action order or other order issued pursuant to Section 78660, 78870, or 79055 who does not comply with that order without sufficient cause shall be subject to a civil penalty of not more than twenty-five thousand dollars ($25,000) for each day of noncompliance. Liability under this section may be imposed in a civil action or liability may be imposed administratively pursuant to Section 79590.