The Federal Energy Management Program (FEMP) has developed a variety of technical resources and tools focused on alternative water.

These resources aim to provide federal agencies with crucial technical information on alternative water systems, facilitating strategic planning for their implementation. Alternative water refers to water sourced from sustainable supplies, serving to mitigate the reliance on fresh surface water and groundwater.

There are a variety of alternative water sources, including:

  • Harvested rainwater
  • Captured condensate from air handling units
  • Reclaimed wastewater
  • Process reuse
  • Graywater
  • Desalinated water

The applications of alternative water range from irrigation to vehicle wash and cooling tower makeup.

Explore the following resources and tools to learn more.

Technical Resources

Alternative Water Projects: Implementation Steps
Step-by-step guide on implementing alternative water projects.
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Rainwater Harvesting Systems: Technology Review
Technical information on rainwater harvesting, describing technical components, operations and maintenance requirements, and system sizing considerations.
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Best Management Practice #14: Alternative Water Sources
Overview of alternative water source types with important considerations.
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On-Site Wastewater Treatment Systems: Technology Description
Technical information on wastewater treatment systems that can be employed for reclaiming wastewater.
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Maps and Tools

Rainwater Harvesting Tool
Geographic Information System (GIS) based mapping tool that provides state-by-state regulations and zip-code-level monthly data to help federal agencies strategically prioritize commercial rainwater harvesting projects.
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Condensate Capture Potential Map
Provides data on the potential for condensate capture from air-conditioning systems across the United States.
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Reclaimed Wastewater Map
Map shows water utilities that sell reclaimed wastewater, which has potential for reuse in applications such as irrigation and industrial processes.
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Rainwater Harvesting Calculator
Calculator that estimates the amount of monthly rainfall that can be harvested from rooftops or other hard surfaces.
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Additional Resources

Alternative Water Treatment Levels: Information on non-potable and potable water treatment to inform the level of treatment necessary for the intended application of alternative water source.