PPD practice exam

Water from dishwasher is considered gray water?

Hi @Gilryong.Song and welcome to the ARE Community!

Good question, I believe that is accurate, however I’ll ask @cat.heard9 as she might be able to provide more useful input.

Hey @Gilryong.Song; short answer is: it depends on who you ask.

  • The Uniform Plumbing Code does not allow water from kitchen sinks and dishwashers to be classified as gray water
  • according to MEEB, gray water is “wastewater not from toilets or urinals”. (It’s further broken down into two categories: dark graywater: “from washing machines with dirty diaper loads, kitchen sinks, and dishwashers” and clearwater: “backwash water from reverse osmosis water treatment; condensation from a cooling coil”).
  • International Plumbing Code defines gray water as: “on site reclaimed water, collected rain water, and waste discharged from lavatories, bathtubs, showers, clothes washers and laundry trays” further clarifying with: “dishwasher waste water and waste water discharged from wet-hood scrubbers shall not be collected for reuse in an on-site nonpotable water reuse system

NCARB references for the PPD exam include both the 2015 I-codes and MEEB. I personally tend to lean toward the code books for the ‘NCARB approved’ answer. Therefore, I believe the correct answers for this question should be:

  • Water from a shower
  • Rainwater
  • Water from a washing machine

I’m wondering if @heatherrivera might have some thoughts on this?

“Gray water is water discharged from lavatories, bathtubs and showers, clothes washers and laundry trays.” (IPC 201). I read that rainwater and on site reclaimed water are lumped in under non-potable sources, but are different than gray water. The answer to me would be only two:

  • water from a shower
  • water from a washing machine

@cat.heard9 throwing this back at you

@Gilryong.Song We’re looking into this internally and deciding if the answer needs to be corrected. Thank you for bringing it to our attention!