DEFINITIONS

There is no specific, universally accepted definition of gray and recycled water. In many cases, the expressions have been used interchangeably. In general, the term gray water is intended to include appropriately treated water that has been recovered from typical fixtures such as lavatories, bathtubs, showers, and clothes washers. Waste potentially containing grease such as that from kitchens and dishwashers are excluded, as well as waste from food disposals in kitchens. Recycled water is intended to include clean water discharged from sewage treatment or other waste treatment facilities that has been additionally treated to remove bacteria, heavy metals, and organic material. Black water is water recovered from plumbing fixtures, such as water closets and urinals, that discharge human excrement. This handbook will limit discussions to gray water only, unless it specifically mentions otherwise.

GENERAL

Gray water systems have been in use for long periods of time in various areas of the world. In localities where the underground aquifers are in danger of depletion and where adequate supplies of water are dwindling, the reuse of water offers a considerable saving of water resources. Wastewater management is also a significant reason for gray water system use.

Onsite reclamation and recycling of relatively clean, nonpotable water is considered for the following situations:

1. In areas where code mandates that gray water be used...