Contact Information:
(505) 827-2855 MAIN // 1-800-219-6157 (toll free)
Environmental Emergencies:
505-827-9329 (24 hrs)
New Mexico
Environment Department

Water Reuse in New Mexico - Treatment Systems

Indirect Potable Reuse (IPR):

Historically there has been unintentional mixing of treated wastewater into streams or reservoirs.  Communities downstream from municipal wastewater treatment have for years been treating a mixture of natural flowing water and diluted wastewater.  IPR is the intentional reuse of treated wastewater.

  • Injecting highly treated municipal wastewater into the ground

  • Allowing highly treated wastewater effluent to mix with natural sources in reservoirs. 

The treated wastewater intentionally mixes with natural groundwater or surface water in the environment before being collected and treated for potable water.

Direct Potable Reuse (DPR)

This process uses highly treated wastewater without the environmental buffers. 

  • Treated wastewater is mixed directly with natural sources such as well water, springs, or surface water before being treated for use as potable water. 

  • In these applications, treated wastewater meets or exceeds standards for drinking water as established by the US EPA in the Safe Drinking Water Act.

  • The treated wastewater is often of much higher quality than the natural waters it is being mixed with.


water cycle diagram

Hydrologic Cycle Diagram

IPR and DPR Mimic the Earth's Natural Water Treatement Processes:

The hydrologic cycle is well known and it shows how water from the oceans is evaporated to precipitate over land masses recharging rivers and percolating through the ground to fill aquifers.  The rivers run back to the oceans to start the process over. 

Water on the planet is finite and therefore we are essentially drinking the same water that the dinosaurs drank.  Under natural conditions the Earth filters the water, although natural occurring minerals are often dissolved in the process. 

With IPR the same processes occur, although the time from use to reuse may be much shorter. 

With DPR, engineered treatment takes the place of the environmental buffers to produce water that contains less minerals than natural water.  Although the time from use to reuse is much shorter than under natural conditions or with IPR, the treatment process is more efficient in removing microbiological and mineral contamination.

Dealing with Contaminants - the Role of Drinking Water Standards:

The US EPA has established a list of water contaminants and the levels at which they become a threat to human health.  All public water systems must test the water they deliver on a routine basis. 

To ensure that potable water supplies supplemented with reused water is safe, these and other potential contaminants are routinely monitored. 

The treatment process is designed to remove contaminants, such as pharmaceuticals and household cleaning products, that would otherwise build up as water is reused several times. 

Monitoring ensures that these contaminants remain at safe or nonexistent levels and that the process is stopped if the contaminant levels rise above predetermined concentrations.


Learn more about NMED's role in keeping your water safe.


Back to Water Reuse HOME

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