32 Pa. Stat. § 5203
The following words and phrases when used in this act shall have, unless the context clearly indicates otherwise, the meanings given to them in this section:
"Bluff." Any high bank or bold headland with a broad, precipitous cliff face, overlooking a lake.
"Bluff line." The edge or crest of the bluff.
"Bluff recession." The loss of material along the bluff face caused by the direct or indirect action by one or a combination of groundwater seepage, water currents, wind generated water waves or high water levels.
"Bluff recession hazard area." An area or zone where the rate of progressive bluff recession creates a substantial threat to the safety or stability of nearby or future structures or utility facilities. The term shall not include any area where the horizontal distance, measured perpendicular to the shoreline, between the shoreline and the bluff toe is in excess of 250 feet and such area shall not be subject to any Environmental Quality Board regulations or municipal bluff setback ordinance or regulation established under this act.
"Bluff setback ordinance and regulations." Building codes, zoning ordinances, subdivision regulations, health regulations, special purpose ordinances, and other applications of the police power, which provide standards for the location of structures and facilities in bluff recession hazard areas.
"Bluff toe." The base of a bluff.
"Department." The Department of Environmental Protection of the Commonwealth.
"Development":
"Lake." A body of fresh water covering at least 9,000 square miles.
"Municipality." A city, borough, town or township, or any county or other governmental unit when acting as an agent thereof, or any combination thereof acting jointly.
"Person." An individual, partnership, public or private association or corporation, firm, trust estate, municipality, governmental unit, public utility or any other legal entity whatsoever which is recognized by law as the subject of rights and duties. Whenever used in any section prescribing or imposing a penalty, the term "person" shall include the members of a partnership, the officers, members, servants and agents of an association, officers, agents and servants of a corporation, but shall exclude any department, board, bureau or agency of the Commonwealth.
"Shoreline." The ordinary high water mark of Lake Erie of 573.4 feet as defined in accordance with the International Great Lakes Datum 1985 (IGLD 1985) as recognized by the United States Army Corps of Engineers.
"Structure." Any man-made object having an ascertainable stationary location on or in land or water, whether or not affixed to the land.
"Structure life span." The useful life of the structure considering both economic and physical factors.
"Substantial improvement." Any repair, reconstruction or improvement of a structure, the cost of which equals or exceeds 50% of the market value of the structure either:
For the purposes of this definition "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor or other structure part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include any project for improvement of a structure to comply with existing State or local health, sanitary or safety specifications which are solely necessary to assure safe living conditions; or any alterations of a structure listed on the National Register of Historic Places or a State inventory of historic places.
32 P.S. § 5203