CSU, Noble Energy and DNR partner on groundwater monitoring project in the Wattenberg field

Groundwater monitoring well
Groundwater monitoring well

From The Greeley Tribune (Sharon Dunn):

Like the crime scene investigators on television, researchers in northern Colorado will be taking an intense look at water wells throughout the oil patch in a demonstration study in the coming months to determine changes in the water over time. Conducted through Colorado State University in partnership with Noble Energy, the Colorado Water Watch demonstration project will soon begin water table monitoring in test wells at roughly 10 Noble production sites in a real-time look at how the water changes.

“It was conceived not so much as a research project but as a tool to provide information to the public,” said project lead researcher Ken Carlson, an associate professor Civil and Environmental Engineering at CSU. “The oil and gas industry is taking the initiative here to provide some visibility.”

The project is funded through the state Department of Natural Resources, with contributions from both Noble Energy and CSU. The project will involve five to 10 test wells, which will be drilled alongside existing wells at Noble Energy sites throughout the Wattenberg Field. The wells will be fitted with a sensor that monitors the water 24/7, which will immediately transmit data back to CSU electronically. CSU teams will monitor the data in Fort Collins. If there are changes in the water, they’ll send a team out to test the water, and send it in for more rigorous testing that will help determine a cause of the changes.

“The in-depth lab testing will give us an indication of the source, almost a forensic analysis,” Carlson said.

Noble Energy officials, Carlson said, are very interested in the project. They believe it will show the public the industry is not a threat to the water systems.

“Noble is very supportive of doing this on their land,” Carlson said.

The COGCC already requires water testing within a half mile of oil and gas wells. That rule came into effect in May of this year, requiring groundwater sampling prior to and after drilling a site.

“We aren’t reinventing the wheel,” Carlson said. “We’re taking a pretty good system with the COGCC, and attaching onto that a watching component. If there is a contamination event, we’re not going to tell people exactly what and how much, but (we) can say something has happened.”

The value of the real-time monitoring will not only be in catching a problem immediately, and working on a fix that much quicker, but seeing long-term changes in the water table and evaluating how it’s occurring. Carlson said an important part of this study is what it’s not. It’s not going to test for specific contaminants.

“Water Watch tells you if something changes,” Carlson said.

It’s looking at the overall health of the aquifer, not drinking water sources.

“If we see a change in conductivity, it will indicate that the produced fluids have contaminated the aquifer,” Carlson said. It piggybacks on the COGCC water testing baselines, comparing data over time to determine of there are any changes.

“We’re looking for two things, conductivity and oxidation reduction potential that tells us if there’s been a change in the fluid, itself,” Carlson said. “If produced water or oil contaminates a well, it will change conductivity. If the methane concentration of a well changes, it will change oxidation reduction potential.”

What’s in your water?

A difficulty in the study is helping the general public to gain an understanding of the conditions and potential contaminants in the water, both naturally occurring and non-naturally occurring. It’s a difficult concept for some to distinguish when the oil and gas industry is so heavily concentrated in the same areas.

“If the Water Watch expands, people are going to become more aware of things in the water, like methane,” Carlson said.

Researchers and geologists have known for decades that there is a naturally occurring coal methane bed beneath the southeast portion of Weld County — as well as several other parts across Colorado — which does contribute some methane to water. In other parts of the state, that methane is drilled and produced commercially, but Weld’s coal bed is not considered commercially viable. A 1976 publication by the state Division of Water Resources noted that the Laramie Fox Hills aquifer, which is below Weld County, had a “troublesome amount of methane,” according to the COGCC.

Naturally occurring methane is called biogenic, and it has a specific fingerprint; thermogenic methane, which comes from the hydrocarbons for which they’re drilling, also has a specific signature. But the presence of biogenic methane has been confusing amid the presence of the thousands of oil and gas wells in Weld County. Carlson said from the outset that there will be some naturally occurring methane in the water that is being tested. The concern with the project is to see how that changes over time — does it grow or have the thermogenic isotopes seeped in indicating a leak in a well? Does it grow so much that residents must take some mitigation measures to allow the gas to evaporate?

“There has always been methane in the groundwater in certain parts of Weld, and it’s largely not related to oil and gas,” Carlson said.

Though the majority of methane found in the water is biogenic, and not in high enough concentrations to cause any health problems, it remains a concern. In its thermogenic form, it is a strong indication that the well bore has been compromised, such as a leak in the casing.

The COGCC reports that there have been no studies linking “ingestion of water containing methane to any short term (acute) or long term (chronic) health effects.” Just as with naturally occurring radon in the ground — which in high enough concentrations can be lethal and cause lung problems in people — methane can be problematic, even in its biogenic form. When it is found in high concentrations, it could cause explosions. It’s the cause of many mine explosions that have made headlines in recent years.

What’s next?

Carlson and his team are still setting up the project, which should be operational by the first quarter of next year. At that time, results of the real-time tests from the Noble wells will be posted on the Colorado Water Watch website. It will be displayed in a reader-friendly way to demonstrate to the public how the water has changed without attaching emotion/opinion to it, Carlson said.

The Colorado Water Watch, though a test function now, could become a part of companies’ best practices, Carlson said. The hope, anyway, is for the testing to show companies the value of real-time changes, as well as the transparency component, that they adopt such monitoring on their own wells.

“It’s not so much as a study as it is a development of monitoring systems,” Carlson said. “We’d hope that these monitoring systems become part of the normal operation of the oil and gas industry in the field.”

Carlson said the demonstration project is unbiased, and without emotions.

“Part of the value is a third party collecting the data and analyzing the data, without making commitments,” Carlson said. “Operators might see a value if a third party is at least the custodian of the data. … This is partially for public transparency.”

Officials also hope the information will prevent a “Gasland III,” which has incorrectly linked biogenic methane-laced water in Colorado to the oil and gas industry, Carlson said. Carlson said there has to be some amounts of rationality to the process as well.

“It’s not like oil and gas is completely blameless,” Carlson said. “They can end up contaminating wells and there have been instances.

“What we’re trying to do at CSU is be the middle person between two polar sides. We just want to provide the information and let people make their own conclusions.

“We want the public to feel there is some monitoring, someone is watching and making the data available to the public to look at and get a feel for what sort of measurements” there are in the water.

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