June 25, 2020

Ranchers, researchers mull using treated produced water for irrigation

Encana Energy Oil Fields (CC BY-SA 2.0) by formulanone

John Norris is worried about where he’s going to get water in the future. Norris is a rancher in southeast New Mexico, where he runs calf-cow and yearling operations. 

“Our water comes from the Ogallala [aquifer]. We’re basically mining this water, whenever it’s gone our water source is going to be gone,” Norris said, adding that in drought years his fields dry up and the grass doesn’t grow. 

“Water is the lifeblood of what we do. It’s very important to me to look for a new water source for the future to be sustainable,” he said. “Sometimes we need just a little bit of water to make it through.”

Related: Amid groundwater declines, water data gains importance

There’s a chance Norris could someday use recycled produced water to help irrigate his ranchland. 

Produced water is an abundant wastewater byproduct of oil and gas extraction activities, including fracking. It typically contains drilling constituents, synthetic compounds and chemicals, as well as naturally-occurring minerals and hydrocarbons. A single barrel of oil produces between four to seven barrels of produced water. In New Mexico, oil and gas operators generated over a billion barrels of produced water in 2018 alone. 

In years past, oil and gas companies simply injected that wastewater back underground for safe keeping. But underground storage isn’t a future-proof solution for the waste. For one thing, recent research has linked injection wells with increased seismic activity and groundwater contamination. Producers are also running out of room underground to store the waste.

In 2019, the state legislature passed a bill that allowed regulators to begin developing permitting criteria and parameters for treating and reusing produced water in other sectors, including possibly agriculture. The New Mexico Environment Department then partnered with the New Mexico State University to establish the Produced Water Research Consortium, tasked with exploring the scientific and technical gaps needed to establish regulations and policies for the treatment of produced water.  

Norris, who also runs an environmental remediation services company, teamed up with Encore Green Environmental, a Wyoming-based agriculture company that’s pioneering what co-founder Marvin Nash calls a patent-pending, technology-agnostic methodology for treating and recycling produced water. 

Encore Green’s system involves testing the water for constituents, treating the water and then retesting after treatment to see if it meets the remediation criteria determined by regulators. The testing extends to the soils where the treated wastewater would be land-applied, to ensure no chemicals or salts build up over time. 

“This is what we’ve invented that’s different from everybody else. Our batching process. If it doesn’t meet those parameters, then it’s got to go back into a normal disposal, or it’s got to be retreated until it does meet those parameters,” Nash said. “We’ve done all the soil science work, we know what the moisture content is, what the nitrogen level is, we know what the salinity is, the density of the soil. Then we calculate how many acre inches we can safely apply to that soil. We connect our agronomy science to our water science, and then we continually monitor that.”

Despite Nash’s enthusiasm, the company may be getting ahead of state regulations. Encore Green conducted a pilot project with a Wyoming cattle rancher in 2018 for treating and land-applying produced water, but the state didn’t yet have a permitting process discharging the treated oil and gas wastewater. 

The Wyoming Department of Environmental Quality sued the company for the alleged discharge of treated produced water on a piece of land without a proper permit. The two parties have since settled the case, while the Wyoming DEQ developed a new permitting framework for land-applying treated produced water. Encore Green was the first company to receive the permit and is planning another pilot for land-applying produced water in Pine Bluffs, Wyoming. 

The Wyoming DEQ did not return NM Political Report’s requests for comment. 

Encore Green, which is a member of the Produced Water Consortium, is now looking for potential partners to license the system for treating and reusing produced water in water scarce agricultural communities near the Permian Basin. Norris is hoping to license the system and get a treatment facility set up on his ranch, though he’ll have to wait until New Mexico regulators develop a permitting process for such applications. 

But there’s still plenty of questions and concerns about how, and if, produced water can ever be safe enough to use on crops—and whether any farmers would even want to use produced water on their land.  

Is it worth treating produced water?

Stakeholders on all sides of the debate agree that oil and gas producers should be reusing produced water in the oil and gas fields whenever possible, which will help conserve freshwater resources. Proponents of recycling produced water often point to the state’s agricultural sector as a significant opportunity to use treated produced water beneficially while also reducing freshwater use.

But the water will need to be treated first for any use outside of the oil fields, and that’s where it gets complicated. Fracking wastewater, a type of produced water, is filled with chemicals and drilling additives, as well as naturally-occurring minerals, hydrocarbons and rare earth metals, and a whole lot of salt. 

Nearly all of these constituents need to be removed before the water can be reused. That’s easier said than done, according to Dr. Pei Xu, the PESCO Endowed Professor and Ward Family Endowed Interdisciplinary Chair in Civil Engineering at New Mexico State University. Xu is involved in the produced water research at NMSU in partnership with NMED. 

RELATED: Characterizing fracking fluids: More details on the state’s plans for produced water

“The constituents in produced water are very complex. It has very high salinity and organics, and many other compounds that could interfere with analysis. That’s why it’s very challenging to analyze those compounds,” Xu told NM Political Report

To make matters worse, many of the chemical additives that oil and gas producers use in fracking fluid are proprietary and largely unknown to both researchers and state regulators. Some research has found nearly 1,200 chemical compounds in produced water, some of which are not regulated. Mike Hightower, program director at the Produced Water Research Consortium, estimates produced water generated in New Mexico contains some 300 chemical compounds.

“That’s a very big research area, actually,” Xu said. “There’s so many constituents in produced water, we may need to establish a library for those constituents. There is consensus that we should further develop the methods for those unidentified compounds.”

Xu is a co-author of a recently published study that examined the potential for treating and reusing produced water for a range of uses, including irrigation. It found that produced water could account for up to 10 percent of water demand for irrigation in the Permian Basin. 

From a basin-wide perspective, 10 percent isn’t really much. But Xu said for individual farmers—like those who rely on the Ogallala aquifer, for example—using treated produced water could substantially help meet irrigation demand. 

“We have to think about the geospatial distribution of produced water,” Xu said. “If a farmer doesn’t have water for irrigation, and the farm is near an oil and gas field, there is the potential for using treated produced water for irrigation. I think for that particular farmer, that is a very impactful water source.”

The energy and financial costs of treating produced water present a whole other host of challenges, Xu said.  

“We have to think about the treatment costs and the water quality, and who will pay. We have all these questions,” she said. “Farmers and ranchers are expecting low-cost water.”

Not everyone believes produced water can be safely treated

Even if the challenges to cost-effectively treating produced water for reuse were solved, it’s still unclear if anyone will want to use treated produced water on their crops. Many farmers and ranchers fear the prospect of contamination, according to Bill Midcap, senior policy advisor at the Rocky Mountain Farmers Union.

RELATED: More questions than answers on how to reuse produced water

“We have to know what is going on our soils before we put it there,” Midcap told NM Political Report. “There’s so many unanswered questions about putting produced water on farmland, rangeland, any kind of land.”

The Rocky Mountain Farmers Union is a group representing some 20,000 family farms across Wyoming, Colorado and New Mexico. Midcap, who is also a member of the Produced Water Research Consortium, said his members are concerned about any reuse of that wastewater that might contaminate food crops. 

“Farmers and ranchers really stake their livelihoods on producing food. They need that food to be safe for consumption,” Midcap said. “In today’s world, we just don’t know what treated produced water would do on farms and ranches, we don’t know what it will do in our streams or our drinking water. We need to have all those things be safe from contamination.”

Midcap is especially worried about Encore Green’s potential involvement in produced water remediation.

“What raises my eyebrows more than anything is their troubled history in Wyoming,” Midcap said, who heard about the permit violation through one of the group’s Wyoming members. “They were bad actors in the first place. And then we didn’t hear about them for a few years, and now they’re here in New Mexico. I think it’s very worrisome that they have announced plans to move forward to discharge produced water on ag lands.” 

Nash argued that his company’s system can work safely and effectively if it knows what chemicals to test for. It would be up to state regulators to determine which chemicals need to be tested for and removed. Those requirements, as well as other possible permit parameters, are being explored now by the Produced Water Research Consortium. 

That’s something Xu and other researchers at NMSU are working on as well. 

“We are very careful regarding the impact of reusing produced water outside the oil and gas field, especially when talking about possibly applying it to land or discharging it into water. We are looking at constituents in the water before and after treatment, and we are looking at their environmental toxicity and their risk analysis,” Xu said, adding that researchers are also looking at what other states are doing with reusing produced water. 

“We are being very careful and very cautious about the impact,” she said.