Frequent Questions

What is the timeline for very small system waivers?

Very small systems do not need to take action to receive a very small system waiver, provided they have existing TTHM or HAA5 data. In most cases, EPA and states intend to work together to send letters to very small systems informing them that they have received a very small system waiver and do not need to take any further action to comply with IDSE requirements. However, the EPA or the state can also request that the system conduct standard monitoring, even if the system meets the criteria for the waiver.

For additional guidance on the Stage 2 Disinfectants and Disinfection Byproducts rule please visit

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