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Treatment Technologies Bring Opportunities for Water Management in the PRB Operators use treatment as another cbng water management tool in the Water Management Toolbox. Treatments such as ion exchange, reverse osmosis and capacitive desalination were severely limited when the first wells were drilled in the Powder River Basin in the late 90’s. A decade later, operators have tested nearly ten different types of treatment methods all across the Basin. Joe Icenogle is a regulatory/public affairs manager for Fidelity Exploration & Production Company, and has a lot of experience with developing technologies. He thinks more companies are beginning to use treatment as a choice, out of several choices, to assure water quality and for responsible water management. “Fidelity would like to be able to provide the treated water to the landowners on whom we operate rather than discharging it into the Tongue River,” said Icenogle. The challenge is keeping the treating standards within economic reach. Other producers in the PRB are utilizing some of the latest technology available. But, the technologies are in early stages and there are no guarantees of success in every instance. Yates Petroleum knew nothing about water treatment technologies five years ago. In a Colorado State University Water Center newsletter, Frank Yates wrote, “After considerable time and money, we’ve moved along that learning curve.” He also wrote, “There is still a lot to learn and a way to go before we are treating meaningful volumes of water, but we believe that we are at the forefront of New Mexico producers who see the value to the state, our industry, and our company in pursuing produced water treatment options.” Just like all of the tools in the Water Management Toolbox, which include: surface discharge, impoundments, irrigation, injection, commercial uses and emerging technologies, the key is applying the tool in the proper circumstance. John Wagner is the administrator of the water quality division in Wyoming’s Department of Environmental Quality. Wagner said treatment also poses some challenges. He said there has been some discussion about discharging treated water into the Powder River because the treated water is cleaner than the natural flowing water in the river. The Powder River is a warm, muddy stream with a low flow and thus has a specific type of biology. The Tongue River, on the other hand, is a naturally cold, clear creek, which can readily accept the treated water. The key, once again, is the PRB is unique and requires site-specific water management solutions. “Treatment can be a good water management tool depending on where you are located and what you plan to do with the treated water,” said Icenogle. An example of one technology the Wyoming DEQ has issued a statewide permit for is EMIT’s ion exchange technology.
Within each technology, alternative technologies exist. To mention a few, there are four types of ion exchange methods, two types of capacitive desalination methods, as well as multiple chemical treatment variations. Each type specifically addresses targeted water quality concerns, on a site-by-site basis. Flexibility is the result is for both the operators and landowners when considering what type of treatment to use, but only when treatment is economical, and therefore, realistic. Wagner said the cost of treatment is the main concern. For instance, treatment methods often need to be coupled with other methods. While combining treatment methods is an effective option, it adds a major cost to the procedure. For example, when using the reverse osmosis technology, the water must be pretreated, which adds additional costs to the process. It is like treating the water twice, then adding the cost of brine disposal to both treatment costs. Costs depend on many variables such as building and maintaining the technology, providing energy required using the technology, the initial water quality and the cost of piping water to a treatment facility. Another concern with treatment facilities is that on fee land, many landowners do not want the surface disturbance. As a result of the numerous variables, a rough estimate can be far-stretched and not even close to a real-cost scenario. Treatment options are also coupled because each method is usually limited to treating specific constituent types, such as total dissolved solids or specific ions. For example, many ion exchange technologies can’t remove organic material. Electro dialysis reversal technologies Other issues must also be considered such as the amount of brine stream that is produced as a byproduct. In some cases, brine stream disposal adds significant costs to treating the water. These costs are also dependant upon many variables. According to Bob Kimball, a chemical engineer, a significant variable is the distance the brine must be shipped. For example, consider a 250-gpm flow with a 25-gpm-brine stream. Kimball said, would result in 63 trips with 4,000-pound truckloads, plus the distance the trucks have to travel to inject the brine stream into commercial injection facilities. In the PRB, these commercial wells are existing wells. When there is not an existing commercial well, other variables such as capital costs in drilling an injection wells (which could be anywhere from $400,000 to three million dollars) are added to the process. Shipping brine, drilling injection wells (depth is a factor), maintenance, and operation fees exponentially increase the cost of the technology. For every project, these considerations, including others, are initially researched for a detailed cost/benefit analysis. “One area of treatment that needs to be clarified to the public is that water treatment technology is not available for “off the shelf” purchase,” Icenogle said. “What we have experienced is that many treatment vendors cannot treat cbng produced water in the volumes we need and with a small enough waste stream to make treatment economically and technically viable.” This chart lists general benefits, adverse effects and costs. Because the initial water quality is different in every situation, the benefits, effects and costs are all variables and each experiment does not always yield the same results.
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