24 Pa. Stat. § 5-503
The board of school directors in any school district may establish and maintain kindergartens for children between the ages of four and six years. When established, the kindergartens shall be an integral part of the elementary school system of the district, and be kept open for not less than two and one-half hours each day for the full school term as provided in section 1501.
The number of kindergartens in any one district shall be fixed by the board of school directors, and shall be open during the school year.
If the average attendance in any one kindergarten in any district is ten or less for the school year, the school directors shall, at the close of the school year, discontinue the same.
The board of school directors shall appoint and assign a sufficient number of teachers to such kindergartens, who shall be certified in accordance with the rules and regulations prescribed by the Council of Basic Education.
24 P.S. § 5-503