Program Information Speech and Language Development Center (SLDC) is a non-profit school and therapy center located in Buena Park and serving Orange, Los Angeles, Riverside, and San Bernardino counties. We serve children and young adults who have special needs in language, learning, and/or behavior. More than 200 staff members provide programs and services for around 300 children and adults ages 5 through 40 years. The majority of our students have a diagnosis of Autism Spectrum Disorder, though many students have multiple conditions. All programs and services are available to students during the school day.