A contractor proposes a site-built concrete gravity grease interceptor with no manufacturer’s installation instructions. Under unamended 2021 IPC Section 1003.3.7, which response correctly addresses the proposal?
- Demonstrate the required capacity and IAPMO/ANSI Z1001 design/testing compliance, and follow the specified fallback installation standards; a large concrete box alone is insufficient
- BReject it solely because all concrete gravity interceptors are categorically prohibited by this section
- CAccept it solely because its liquid capacity exceeds 750 gallons
- DTreat it as outside the plumbing code because it is built on site
Where to look it up
https://www.ncosfm.gov/b-1-2024-ncpc/open
Why A is correct
Section 1003.3.7 requires gravity-interceptor design and testing in accordance with IAPMO/ANSI Z1001. Capacity is based on peak inflow in gpm times 30 minutes. Where manufacturer instructions are absent, installation must comply with ASME A112.14.6 and IAPMO/ANSI Z1001. Merely obtaining a general approval or choosing a gallon capacity does not waive these requirements. Applicable local utility/health rules must also be checked; this model provision alone does not guarantee acceptance of any particular site-built tank. See PDF p.142. Source: https://www.ncosfm.gov/b-1-2024-ncpc/open