HHSC Benefits Office- Castroville SNAP Office is situated at 2534 Castroville Rd San Antonio, TX – 78327.The Supplemental Nutrition Assistance Program. commonly known as SNAP, is a federal program that helps millions of low-income households purchase nutritious food. To determine eligibility, individuals must fill out an application and provide all the required documentation. Approved recipients receive the SNAP benefits, which can be used just like a debit card at any authorized retailer that accepts SNAP. Contact the office for further information.