Much is written about fracking fluid and whether wastewater treatment plants can and should accept it. But another kind of water from oil and gas production also needs proper handling, and Colorado’s Clifton Sanitation District is part of a promising potential solution.
Fracking fluid is used in hydraulic fracturing of shale formations to release natural gas that is otherwise unavailable. It contains sand and various chemicals. After it is injected deep in the earth, much of it returns to the surface and needs treatment.
Produced water is water present in underground oil and gas formations; it comes to the surface during conventional drilling. Clifton Sanitation, in western Colorado, has teamed with Concord Produced Water Services to test the feasibility of treating the water, which typically is placed in evaporation ponds.
The plan calls for Concord to install a pretreatment system at Clifton Sanitation’s 2.5 mgd (design) oxidation ditch wastewater treatment plant. The Clifton plant would further treat the effluent from the Concord system, and in the process earn revenue. It’s a produced water management approach that may have potential to expand to other treatment plants in the region.
Brian Woods, district manager for Clifton Sanitation, talked about the project in an interview with Treatment Plant Operator.
TPO: Where exactly does this produced water come from?
Woods: Here in Western Colorado, we are in the second big boom for oil and gas. Produced water as a rule is generated for the life of the well. My understanding is that for every one gallon of product they pull out of the hole, there are four to five gallons of produced water that has to be taken care of. It tends to be lumped in with fracking, and that leaves people with a bad taste — but produced water is a very different item. We hope to take produced water from the Piceance basin, which is world renowned for its natural gas reserves.
TPO: What is typically done with produced water?
Woods: Produced water can be reinjected into the wells or used for dust control on the production sites. However, only a certain amount of the water can be handled in those ways, and so eventually some needs to be treated. In our area, it is generally placed in evaporative ponds. This leads to two potential concerns: air emissions and a solid waste product — the pond sediment — that eventually will require disposal on a large scale. There is concern in the oil and gas industry that ultimately the material may need to go through an additional treatment process.
TPO: What does produced water contain that is of potential concern?
Woods: It can contain a blend of hydrocarbons, although less than is typical of fracking water. For the most part the hydrocarbons are easily separated, and there is a financial incentive to capture them for beneficial use. But some hydrocarbons can’t be as easily removed. The water can also contain a variety of metals. The biggest concern from our treatment plant’s perspective is the high concentration of naturally occurring total dissolved solids associated with the oil shale formations in our region. These formations are naturally high in salts, and when water is introduced, high concentrations of salt are dissolved, creating levels of TDS that are excessive and difficult to treat conventionally. The Concord pretreatment process would be removing most of the TDS before discharge to our system. That is a key component in the process.
TPO: How did this project with Concord come about?
Woods: Clifton Sanitation started receiving holding tank wastewater from man camps. As long as it isn’t in a septic condition, we can treat it in compliance with federal or state requirements. After discovering this activity, a local friend, Shawn Marsh, owner of Marsh Trucking, a company that hauls produced water, inquired about the possibility of treating produced water at our facility. He introduced me to Eric Gopsil, who at the time was vice president of Concord Produced Water Services. Previously, Eric had been a construction supervisor for a company that builds water and wastewater treatment plants. Shawn and Eric are solid people, and I felt comfortable having discussions with them. One thing led to another, and Eric took the ball and began to run with it. We started researching what it would take to get a pretreatment facility permitted by the U.S. EPA and the Colorado Department of Public Health and Environment [DPHE].
TPO: What was your experience with the permitting process?
Woods: We initially asked if we could perform a pilot study to see if what we were proposing would be feasible. As it turned out, to reach the point where we could test the process, we had to go through the full permitting process. Lisa Knerr, who oversees the pretreatment program for the CDPHE, worked with Clifton and Concord and our consultants to develop a Notice of Discharge Requirements [NDR] so that we could get the project off the floor. There were a few other steps. The EPA had to provide a ruling on whether Concord would be considered a categorical industry. The EPA ruled that they were not, and therefore the NDR from the state would apply.
TPO: Assuming this project ultimately goes forward, what is the benefit to your district?
Woods: We are able to take unused capacity in this plant, which went online in 2008, and basically lease it to Concord on a pay-as-you-go basis, at a rate that is financially viable for them. So we are able to use that capacity until development comes back up. It enables us to evaluate potential early debt reduction and possibly fund future capital projects. It also gives us an opportunity to control and possibly even reduce our service fees.
TPO: How would Concord benefit from the project?
Woods: They benefit from having a permitted facility, monitored and regulated by the government, and they can sell that to their oil and gas customers. It’s a cradle-to-grave solution for produced water. Air emissions are controlled in a closed-loop system. Both the solids stream and the water stream are taken care of simultaneously and continuously. The minimal amounts of solids are dewatered, stored for a short time, and tested for disposal, whether at a landfill or by more stringent practices. The water stream is treated by Clifton Sanitation and discharged under the water-quality standards established by the EPA. Concord will have to sell this concept to the oil companies. At the end of the day this may be more cost-effective for them than existing practices, even if they have to pay a little more. The benefits have the potential to be valuable to all parties.
TPO: What is the current status of the project and what is the timetable for completion?
Woods: Right now we have the necessary state and EPA permits — that process took about 18 months. Clifton Sanitation has tentatively prepared a discharge agreement with Concord. The final step is to receive a conditional use permit from the Mesa County Commission. We expect to have all the permitting in place and to be able to start up sometime in June or July unless there are any unforeseen obstacles.
TPO: What will be involved in the Concord pretreatment process?
Woods: Concord will receive produced water from trucks and transfer it to above-ground storage tanks. The water will be treated to remove organics, TSS and heavy metals. That treated water will be sent to clean storage tanks and then run through a reverse osmosis process to remove dissolved solids. The water will then be sampled and tested to ensure compliance with the local and federal permitting requirements and then discharged to our facility for additional treatment.
TPO: What will the water look like when it comes out of Concord’s process and into the Clifton treatment plant?
Woods: After meeting discharge compliance the water will have acceptable levels of TDS, BOD and heavy metals and will be cleaner than most residential wastewater received at the facility. We expect the water to actually dilute the influent at the facility.
TPO: Assuming your venture is successful, is this something that could replicated by other communities in oil- and gas-producing areas?
Woods: I really do think so — it could be beneficial to other communities. I believe we need to support the industry that provides us with energy resources. Someone has to seek solutions, and being a part of that is important. If we can demonstrate success, I think facilities in a lot of other communities could be equally successful.
