Reg. 86 – Graywater Control

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On February 2, 2022, the Water Quality Control Commission (“commission”) held an informational hearing to obtain feedback regarding a proposed rulemaking scope to update Regulation 86: Graywater Control Regulation.

The commission agreed that the proposed rulemaking scope would include the following items:

  • Align formatting and organization with other codes and reuse regulations to the greatest extent possible
  • Improve organization, clarity, and readability of Regulation 86
  • Clarify the “graywater control program” requirements
  • Address how local graywater programs will address changes in regulatory requirements (updates to the regulation, updates to treatment, and existing systems)
  • Consider the adoption of Log Removal Targets (LRTs)
  • Address special considerations for local graywater control programs within phosphorus control basins
  • Consider whether to add to the scope and process for regulatory variances
  • Review the subsurface use framework
  • Evaluate additional graywater uses
  • Encourage small-scale graywater use by clarifying “laundry to landscape” requirements

The Water Quality Control Division (“division”) led a stakeholder group through these items to develop a recommendation for the commission on November 13, 2023.

What is graywater?


Graywater is a part of the water used in a residential, commercial, or industrial building that may be collected after the first use and put to a second beneficial use. Regulation 86 outlines requirements, prohibitions, and standards for graywater use for non-drinking purposes. Graywater sources may include water discharged from:

  • Bathroom and laundry-room sinks
  • Bathtubs
  • Showers
  • Laundry machines

Graywater may not include water discharged from:

  • Toilets
  • Urinals
  • Kitchen sinks
  • Dishwashers
  • Non-laundry utility sinks

Regulation 86 is part of the legal framework for graywater use in Colorado. The Colorado Plumbing Board must also adopt a version of the Plumbing Code that allows graywater piping within buildings. Graywater use must comply with Colorado water rights regulations. Local jurisdictions must adopt an ordinance or resolution to allow graywater use. Check with your city or county for local graywater programs.

How to get involved



The stakeholder meetings for this effort are complete, and the division would like to thank stakeholders for their participation. The division will present the developed proposal for Regulation 86 to the commission on November 13, 2023.

Sign up to receive notifications about this effort and scroll down to select “Reg 86 - Graywater.”

Please visit the commission's hearing web page for information about ongoing and recently completed Water Quality Control Commission hearings.


Meeting recordings, chats, and other materials are available in this public folder.



For more information about graywater, please see the graywater information sheet.


For more information about Regulation 86, please contact: