Obtain inflow rate and BOD 5 results in page 529 for question 6-7 by multiplying the flow rate by (1+N0.1) and B OD 5 by (1+N0.05) 4. The first consolidated design criteria were adopted by Texas State Department of Health in 1950. What are the advantages of an aerated grit chamber 3. History of Wastewater Treatment Design Criteria in Texas Note: If your facility was approved and built on or before August 27, 2008, and designed under 30 TAC Chapter 317, follow those rules for operation and maintenance only, not for a new design.