Greening Tinker: Water treatment plant gushing about conservation effort

Published July 22, 2011
By Brian Schroeder
Tinker Public Affairs

TINKER AIR FORCE BASE, Okla. -- In a time of budgetary constraints and limited resources, one department on Tinker has taken the initiative to reduce operating costs and energy savings by streamlining their daily operations, introducing innovative technology, and eliminating unnecessary waste, saving Tinker approximately $22 million over the past 11 years.

Rather than waiting for Department of Defense mandates or regulations, Dr. Freddie Hall, environmental engineer and industrial wastewater treatment plant engineer with the 72nd Air Base Wing Civil Engineer Directorate, developed a dynamic strategy when it comes to regulation compliance.

"We took a proactive approach to safety and environmental initiatives years ago, but didn't call it 5S+1 or VPP," he said. "We identified opportunities to streamline our processes to make them safer, more environmentally friendly and more resource efficient. We worked with process engineers upstream to quantify their needs for current and projected future workloads. Then, we try to make plans accordingly so we can meet those requirements."

Over a decade ago, the Industrial Wastewater Treatment Plant was considered an eyesore to many people. Since that time, the IWTP team has done a tremendous job cleaning up the facility. During the first wave of re-structuring 10 years ago, half of the 28 process units used to treat industrial wastewater were either removed or shutdown because they consumed an unnecessary amount of energy, or were no longer needed for a changing waste stream.

"We were able to streamline our processes and eliminate about 14 process units and save approximately 50 percent of our energy and operating costs," Dr. Hall said. "We have taken on a lot of environmental initiatives to try and simplify our operations. If something was not running properly and we didn't need it, we just shut that part of the plant off or removed it."

Dr. Hall said he and his co-workers identify and shutdown redundancies within the wastewater treatment process, which reduces unnecessary energy costs and the need for additional plant maintenance. Most of the industrial wastewater flow is seasonal, running a peak of 1.2 million gallons of wastewater during the summer and only half of that load during the other three seasons. High-peak season requires the use of more processing units. However, during low-flow periods, a smaller number of process units are required. Throughout the past decade, Dr. Hall estimates this initiative alone has saved more than $2 million in energy and operating costs.

"Having the flexibility to shut several process units down (during spring, summer and fall), we have saved over $200,000 per year over the last 11 years, and that's a conservative figure," Dr. Hall said. "This was just an attempt to simplify and optimize our processes to make them run more efficiently while being more conservative in our consumption of resources."

Approximately 10 years ago, Dr. Hall determined 80 percent of heavy metals, suspended solids and organic pollutants came from chemical stripping operations of aircraft and components. The industrial wastewater treatment plant team looked at what they could do to pre-treat that concentrated waste stream. Working with the Air Force Research Lab, Tinker helped design, test, demonstrate and validate an innovative industrial wastewater treatment technology called an air-sparged hydrocyclone. The technology vertically spins wastewater, allowing the heavier solid particles to drift to the outside of a chamber and the cleaner water coming up through the center of the machine. This process is repeated through four stages, removing more than 98 percent of heavy metal particles, oil and grease, and solids.

After the installation of the hydrocyclone, Dr. Hall said the plant operates well under the below 10 percent permit limits, allowing the installation to accept more workload. It also relieves the aircraft production operations of limitations by allowing for more aircraft to be stripped of paint without coming close to the permit limits.

"In the past, the plant had to juggle our processes around, almost weekly, depending on how many aircraft they were going to strip," he said. "Now they can strip paint off as many aircraft as they want to in a shorter time period with fewer constraints. We don't have to worry about coming close to the permit limits so we can accept additional workload if we need to without being concerned. The Industrial Wastewater Treatment Plant is no longer the weak link in the chain."

Dr. Hall's innovation and imagination has him searching for new ways to lower energy costs. However, lack of funding is keeping his ideas on the drawing board. The plant treats approximately 300 million gallons of wastewater per year through miles of industrial wastewater collection systems and then through the IWTP. About 700 million gallons of potable well water is used annually. Dr. Hall's latest energy conservation idea is to reclaim kinetic energy from potable water and wastewater moving through the water collection systems and IWTP via turbines or paddles, similar to turbines at a hydro-electric plant. The reclaimed energy can power water pumps and lift stations, and possibly make the industrial wastewater treatment plant completely self-sustaining. His idea to reclaim kinetic energy through water flowing in the pipes would be the first of its kind on a military installation.

"I don't know of anyone in the DOD or private industry who is doing it," he said. "It's just one of my ideas that seemed to have some merit. With as much water as we move, it looks like we can collect some of that energy and power some places on post."

The industrial wastewater treatment facility has been contractor-operated since June 2000. The contracted staff he works with has a positive attitude toward their job and open-mindedness that contributes to the successes of the wastewater treatment mission.

"The contractors have been very good to work with, very proactive about things and receptive to new ideas," Dr. Hall said. "Much of the success we have had is due to their help. They always have ideas on how we can improve things."

All wastewater that is discharged to the wastewater treatment plant comes from industrial processes, such as aircraft painting and paint stripping, parts inspection and plating shop operations.

"For an industrial plant our size that gets the variety of wastewater coming from so many different shops, it is good quality wastewater that is released," he said. "For example, mercury has some really low permit limits. To meet those permit concentrations, the plant must discharge wastewater that is measured in one-tenth of a part per billion concentration. To place this in perspective, one-tenth of a part per billion is equivalent to one-tenth of a drop of water in an Olympic sized swimming pool. The plant not only meets this strict limit, but operates at roughly two percent or less of the amount we are allowed to discharge. We do this for not only mercury, but also cadmium."

One of the IWTPs biggest successes has been its hazardous waste minimization efforts. Twelve years ago, Tinker's IWTP hazardous waste stream accounted for 39 percent of the total Air Force's hazardous waste. To reverse this trend, the IWTP installed a second plate-and-frame filter press to dewater the sludge prior to disposal. The filter press reduces the amount of sludge disposed and associated disposal costs by 92 percent. Because of this waste minimization effort, more than seven million pounds of hazardous industrial sludge are diverted from the hazardous waste site each year, saving the base over $1 million annually in disposal costs. Over the last ten years, roughly 70 million pounds of sludge have been eliminated from hazardous waste landfills.

"That's the equivalent to filling (University of Oklahoma's) Owen Stadium over 76 feet deep in hazardous sludge," Dr. Hall said. "That's quite a bit of sludge we have kept from going to a hazardous waste landfill. The cost of installing this equipment was nearly three-quarters of a million dollars, but the payback has saved us $12 million. The filter presses have run for more than 10 years with little to no repair necessary. They are really good workhorses."

Hill and Robbins Air Force Bases along with McAlester Army Depot have visited the industrial wastewater treatment plant and were impressed with operations and quality of the wastewater discharged, Dr. Hall said. Environmental engineering and environmental science classes from the
University of Oklahoma and Oklahoma State University also routinely visit the plant as a learning tool.

"We have always been willing to show off our plant and are very proud of what we do," he said.

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