• Methacton contracts all our per diem substitutes and long-term subs through Substitute Teacher Service (STS).  STS is located in Aston, PA with additional offices in Lancaster, Harrisburg, Hatboro-Horsham, as well as Newport, DE.  They service several districts in the tri-county area.  Please visit their website at www.thesubservice.com or contact them by phone at 610-566-6466 (outside the 610 area call 800-357-SUBS) for additional information. Application can be made online through their website.