Less Water, Less Contaminants, Less Problems

June 11, 2020
Innovative steps on water mitigation on the airfield will build a better environment on the airfield.

Edmonton International Airport (YEG) is testing a new filtration system to release clean water back into the local ecosystem.  

Edmonton uses about 4 million liters of deicing fluid each year. The airport is utilizing a new portable filtration system for its stormwater ponds to remove the fluid from stormwater runoff. 

Steve Maybee, vice president of operations for YEG, said the initiative started when airport leaders wanted to tackle challenges with deicing fluid. As the airport continued growing in recent years, there was a concern current retention ponds weren’t big enough to address runoff issues.

Edmonton wanted a solution without a major capital cost. Given its history of innovation, they took a chance at a technology new to the aviation industry.

“We didn’t want to build more ponds because that can create a bird issue,” he said. “We want to find an alternative solution than having storage ponds all over the airfield.”

The Swirltex filtration technology allows YEG to be able to release clean and filtered water back into the local Whitemud Creek. Suspended solids, oil and other contaminants are channeled away from the membrane surface, reducing fouling, allowing more clean water to pass through the membrane pores, resulting in clean, consistent quality water.

Peter Christou, president of Swirltex, said ceramic membranes stain when used with oil/water separation. Swirltex spins the water in the tube to create a centrifugal force in order to draw the oil to the center so it doesn’t come into contact with the membrane.

Christou said when adding air into the process during wastewater treatment, they can manipulate the buoyancy of other contaminants, so they also don’t have contact with the membrane. 

Swirltex was using its product to help rural communities filter wastewater using a portable product. When Edmonton called to try it at the airport, it allowed Swirltex to use the product in a similar manner.

One Swirltex unit can filter about 3,000 cubic meters per day.

“A lot of the engineering costs and infrastructure costs that are normally in an airport job was gone,” Christou said. “It was very easy to just put a unit down there, operate it and get the results it’s looking for.”

Maybee said the Swirltex filtration unit is already being used in the oil and gas industry so the airport wanted to try it for a similar usage at their facility. They decided for the test run in April. If the results pan out, the airport will determine if it will incorporate it into their daily operations. 

“You can only build ponds so big before you need to look at other ways of dealing with fluid,” he said.

The technology can also reduce EIA’s future need to build larger water treatment facilities. 

Christou said the system would also benefit airports in direct glycol recovery. The membrane would make it beneficial in that application.

Christou said airports determine their strategy for wastewater treatment and determine if they want to make a comprehensive plan to treat glycol water not as waste, but a resource.

“The membranes we use are the same pore size they use for drinking water,” Christou said. “So we can get the water or glycol to extremely high purities with extremely low energy.”

Maybee said airports need to find the right partner with the technical expertise to understand what your containment is and how it needs to be treated.

“It’s about being innovative together,” he said. “This company hasn’t done this kind of application so we’re potentially opening them up to a whole new industry for them to apply this equipment in.”

Myrtle Beach Finds a solution in bad soil

Myrtle Beach International Airport (MYR) recently installed a new stormwater management system as part of its upgrades to Taxiway A.

MYR’s coastal location makes it susceptible to severe weather such as hurricanes. The airport needed the stormwater system to address these events along with the area’s annual rainfall average of 50 inches.

Douglas Sander, vice president, Delta Airport Consultants, said the airport is also very flat. The existing ditches retained water, so it was a major challenge getting water off the airport.

“On top of that, we had to construct a pavement box with a thickness big enough to accommodate the larger jets that are using the airport,” he said. “Trying to fit those two things together where you have not much fall for water to go and then putting a thick pavement box on top of that, those were the biggest challenges.”

The apron plan was also an add-on to the original improvment plan. Sander said when designing the taxiway, they did take into consideration the area would eventually be converted to an apron, so they had already accounted for the additional impervious area as part of the stormwater catch.

The project faced issues with soil quality and fiber optic infrastructure buried less than 10 feet underground. The ground needed to hold the pipe, six inches of stone, six inches of cement-treated base and 16 inches of concrete.

A person walking on the ground could sink up to their knees.

“The soil was considered unsuitable because it had a lot of organic material in it,” Sander said. “Organic material is bad, it will not compact, it will not support the weight above it.”

PSI of Conway LLC replaced unsuitable soil with compacted #57 stone to stabilize the stormwater management system constructed with 6,500 feet of FFA-approved Class 5 C443 reinforced concrete pipe (RCP).

The four large drainage structures supporting the system each weighed about 25 tons to support the aircraft taxiing above the surface.             

Rather than installing a traditional single culvert of large diameter RCP, they installed multiple culverts of smaller RCP side-by-side to avoid the fiber optics while still meeting stormwater specifications.

“We’ve never laid this much pipe like this the way we did it,” said Keith Mesimer, owner PSI of Conway LLC. “We went ahead and cut all the dirt out, got it down to grade and then put our 57 on the bottom on the whole entire run and we put pumps on both ends, so if it rained, it would stay dry at all times.”

The Taxiway A stormwater management system features triple culverts of 36-inch RCP, triple culverts of 30-inch RCP, quintuple culverts of 24-inch RCP and more than 36,400 linear feet of underdrain installed across 12 work areas.

“As fast as they could get the pipe to us, we were laying it because it was already on grade,” Mesimer said.

PSI of Conway had to remove all of the bad dirt along the project area and replace it with a suitable material. Mesimer said about 70,000 yards of dirt was replaced.

The project was started after a major 2018 hurricane and during construction was interrupted by another hurricane. Preparations ensured work wasn’t damaged by the storm.

“All in all it was a success,” Mesimer said. “It turned out very well and everyone involved was pretty proud. There were a lot of hours put in, but at the end when you see the finished product and everyone is happy, it makes you feel good.”