Chapter 401.1 Link

Activities such as filling or excavating wetlands, relocating streams, or constructing bridges/roadways over water typically require this certification.

In the context of the Americans with Disabilities Act (ADA), Section 401.1 defines the . Chapter 401.1

Systems for hazardous exhaust or energy recovery must also comply with Chapter 5 of the IMC. 3. ADA Standards for Accessible Design (Section 401.1) Chapter 401.1

States like California or Illinois have 30 days to notify you if your application is complete. The certifying authority then has a "reasonable period of time" (not exceeding one year) to act on it. Chapter 401.1

This is often cited as "401" or "401 Certification" and is one of the most significant environmental regulations in the U.S..