Iowa Code
Chapter 137F - FOOD ESTABLISHMENTS AND FOOD PROCESSING PLANTS
Section 137F.12 - Plumbing.

137F.12 Plumbing.
A food establishment or food processing plant shall have an adequately designed plumbing system conforming to at least the minimum requirements of the state plumbing code, or local plumbing code, whichever is more stringent. The plumbing system shall have a connection to a municipal water and sewer system or to a benefited water district or sanitary district if such facilities are available.
98 Acts, ch 1162, §17, 30