The following terms have the meanings indicated. Terms Defined. “Abate” or “abatement” means the elimination of exposure to lead-based substances that may result in lead toxicity or poisoning, by the removal or encapsulation of lead-containing substances, by thorough cleanup procedures, and by post-cleanup treatment of surfaces. “Business entity” means a partnership, firm, association, corporation, sole proprietorship, or other business unit and any employee of it. “Child” means a person under the age of 6. “Contractor” means any business entity, public unit, or person performing the actual abatement for a lead abatement project. “Department” means the Maryland Department of the Environment. “Encapsulate” or “encapsulation” means to resurface or cover surfaces and to seal or caulk seams with durable material, so as to prevent or control chalking, flaking lead-containing substances from becoming part of house dust or accessible to children. “HEPA” or “high efficiency particle air” means a filter capable of filtering out particles of 0.3 microns or greater from a body of air at 99.97 percent efficiency or greater. “Lead abatement project” means any work performed in order to abate the presence of a lead-containing substance. “Lead-containing substance” means any paint, plaster or other surface coating material containing more than 0.50 percent lead by weight calculated as lead metal in the dried solid, or more than 0.7 milligrams per square centimeter by the X-ray fluorescence analyzer. “Owner” means a person, firm, corporation, guardian, conservator, receiver, trustee, executor, or other judicial officer, who, alone or jointly or severally with others, owns, holds, or controls the whole or any part of the freehold or leasehold title to any property, with or without accompanying actual possession of it, and shall include in addition to the holder of legal title, any vendee in possession of it, but may not include a mortgagee or an owner of a reversionary interest under a ground rent lease. “Public unit” means: Any agency, bureau, department, or instrumentality of State government; Any agency, bureau, department, or instrumentality of federal or local government; Any public, quasi-public, or municipal corporation. “Quantitation limit” means the minimum quantity or level of lead that can reliably be measured or quantified to a specified degree of accuracy and precision. “Woodwork” means all wooden or metal interior or exterior fittings or ornamentation, such as moldings, doors, staircases, and window sashes and trim. Work Area. “Interior work area” means a hallway, room or group of rooms in which abatement takes place on the inside of a residential property, or group day care center. “Exterior work area” means an outdoor porch, stairway, or other element of woodwork on the exterior of a residential property, a group day care center, or a building appurtenant to a residential property or group day care center, on which abatement takes place.