Any spillage or dripping of any petroleum product on airport property must be removed immediately by the operator or owner of the cause or source of spillage or dripping, or by the tenant, concessionaire or other person responsible for the spillage or dripping, in a manner consistent with recommendations of the Department of Environmental Conservation. Any costs incurred by the city for removal of hazardous materials or contaminated soil shall be reimbursed by the persons responsible for the spillage. (Prior code § 5.30.280)