Aquifer Injection Project Earns UOTF Designation for Rio Rancho, N.M.

Nestled in the heart of the arid U.S. southwest, the City of Rio Rancho, N.M., depends on healthy groundwater aquifers as its sole source of drinking water. However, while U.S. Geological Survey data suggest lower-than-average water levels in many of the state’s aquifers, Rio Rancho’s drinking water supply remains plentiful thanks to the Rio Rancho Pure project.

The City of Rio Rancho opened New Mexico’s first direct aquifer injection well in 2017, aiming to enhance the arid city’s water security through indirect potable reuse. Rio Rancho Utilities Department (RRU) received a Utility of the Future Today designation from the Water Environment Federation (Alexandria, Va.) and its program partners for the project as well as the utility’s progressive organizational culture. Image courtesy of the City of Rio Rancho

The project, managed by the City of Rio Rancho Utilities Department (RRU), included construction of New Mexico’s first aquifer injection well. Each day, the utility has deposited approximately 1.7 million L (450,000 gal) of highly treated wastewater into the aquifer since injections began almost 3 years ago. 

“The City of Rio Rancho is constantly exploring ways to create a sustainable future, so it came as no surprise that, in 2017, we made history when we became the first city permitted in the state of New Mexico to start replenishing our groundwater supply by recycling and putting water back into the aquifer,” said Rio Rancho Mayor Greg Hull in an email. “Since that time, we have been storing water for future use and, at the same time, ensuring our long-term groundwater viability.”

The Water Environment Federation (WEF; Alexandria, Va.) and its partners celebrated RRU as a Utility of the Future Today (UOTF) during WEFTEC 2019 for its trailblazing water reuse efforts.

Rio Rancho Pure

The origins of the Rio Rancho Pure project date back to 2001, when the city set a goal to reuse 100% of treated effluent produced by the city’s water resource recovery facilities (WRRFs), according to Rio Rancho’s UOTF submission. In 2005, RRU constructed two new WRRFs with membrane bioreactor technology, aiming to treat the city’s wastewater to a quality fit for reuse.

Rio Rancho’s aquifer injection project was an excellent fit to help enhance water security in the region. The utility’s nearly 100,000 customers depend on groundwater as their sole source of drinking water. The area typically receives no more than 20 cm (8 in.) of precipitation per year, according to RRU’s Utility of the Future submission documents. Image courtesy of the City of Rio Rancho

Because aquifer injection was a novel idea in New Mexico, the permitting process was complicated both for RRU as well as its regulators, the New Mexico Environment Department and the Office of the State Engineer. Extensive outreach and close cooperation over several years drove the development of sensible regulations, culminating in the state government allowing RRU to return up to 3.8 million L/d (1 million gal/d) of purified effluent to the aquifer under the project.

Drilling began on the state’s first injection well in 2010, followed by a pilot study to test the concept in 2011. Over the next few years, RRU and its contractors established new conveyance lines to direct effluent from the city’s WRRFs to the injection site, as well as large storage tanks and pump systems. This coincided with additional upgrades to WRRF technology, including ozone and ultraviolet disinfection and biological granulated carbon treatment. 

Empowering the Next Generation

The UOTF designation from WEF and its partners not only recognizes outstanding technical achievements, but also the utility’s presence in its community. While water customers traditionally have been content to keep their utility out of sight and out of mind, today’s most successful utilities undertake activities to enhance customer trust and understanding.

In its UOTF submission, RRU describes its approach to community development that includes mentoring young people interested in water careers. The utility routinely employs high-school-aged interns, who not only help in RRU offices, but also participate in water conservation outreach programs. These interns also join utility staff members as they work within the community to find and fix water leaks.

Along with the aquifer injection project, RRU also invested in such cutting-edge wastewater treatment technologies as ozone and ultraviolet disinfection as well as biological granulated carbon treatment to ensure its effluent was of suitable quality for reuse applications. Image courtesy of the City of Rio Rancho

RRU also participates in a work-study program with the local university. The program offers college students the opportunity to gain valuable experience in their field of study. This program is not limited to students studying technical topics; for example, one recent intern studying public administration helped coordinate the utility’s governing body and committee meetings.

RRU also performs public education to ensure the community knows about its groundbreaking technical projects. During each phase of the Rio Rancho Pure project, utility staff created an online newsletter detailing the project’s current status as well as why it was necessary. And the outreach appears successful, as the utility faced no significant pushback from its customers during the establishment process.

“Water is our most precious natural resource and, here in the southwest, we need to conserve as much of it as possible,” said mayor Hull.

⁠— Justin Jacques, WEF Highlights