New engineered wetlands in Logan a first in Utah
Logan City will begin construction in April 2002, of a 240-acre engineered wetland to replace the city’s lagoons and provide effluent waste treatment in a project unprecedented in Utah.
The current lagoon system was built in 1968 and has been working well and at a very low cost, said Public Works director Kevin Hansen. But in the last three years, changing standards for ammonia removal have made it necessary to amend the system.
Hansen said the city has looked at many alternatives for waste treatment, but he said he feels the wetlands are the best option.
“The wetland system will improve the water quality. The city really needs it, and it will be a boon to us. We are comfortable and confident that this is a very good way to treat our concerns,” Hansen said.
The Utah Division of Water Quality (DWQ), however, is unsure about whether the project should be implemented immediately, director Don Ostler said.
“The major concern with the wetlands proposal is its ability to meet effluent limitations for ammonia, reliably and consistency, especially in cold weather,” Ostler said.
He said the state has been stating their concerns about the project since it was first introduced, and those concerns have not changed.
“Wetlands can be an effective treatment, but each is unique. You can’t be sure whether it will work or not unless there is a site-specific pilot project,” Ostler said.
Logan City officials said they feel there are ample precedents.
More than 200 engineered wetlands are currently in operation throughout North America, and while many of those are in warm climates like Orlando, Hansen said other wetlands have been implemented successfully in Alaska, North Dakota, Nevada and Oregon.
“It’s not a new technology,” Logan City Mayor Doug Thompson said. “It’s old technology being implemented in a new way. Wetlands naturally clean water. Engineering them simply manages so you can get the maximum effect from what you’re trying to do.”
The main problem Ostler said he sees is the unpredictability of the system.
“It’s not like an engineered project. There is no reproducible data, and we don’t feel there is sufficient information to say it will work,” Ostler said.
Hansen said he understands the DWQ’s position.
“As a regulatory commission, they have to be sure we meet the standards,” Hansen said. “They need that assurance. But the more research I see, the more I am convinced that wetlands will give us the greatest gains,” Hansen said.
The biggest benefit cited by Thompson, Hansen and Ostler was cost.
Thompson said engineered wetlands cost one-fifth to one-tenth as much as a mechanical system.
Hansen said all the other alternatives the city looked at were very costly both for initial construction and operating costs, but wetlands have very low operating costs and are less expensive to build.
“In a mechanical system you put in chemicals, take out chemicals and have to get rid of all the waste. But we won’t pay anything for the plants to do the same thing,” Hansen said.
Hansen said the state has become more supportive of the project as more research has been done.
“Their view has gone from, ‘What can I do to kill this project?’ to, ‘What can I do to help Logan make this work?’ They are encouraged by the opportunity they have not only to benefit our community, but the entire state,” Hansen said.
Ostler said it will be a nice system to demonstrate in Utah because there are none currently operating in the state.
Because the feasibility of the system in the cold weather is one of the major concerns, Hansen said Logan is the perfect place to initially implement an engineered wetland.
“If it works here in the cold part of the state, imagine what it could do in St. George or Kanab,” Hansen said.
The DWQ encouraged Logan to proceed with caution, Ostler said, and to do so pessimistically.
“Always assume the coldest temperatures, the longest winters and the highest cost,” Ostler said.
Thompson said, “The DWQ is not used to lagoons or engineered wetlands. They know the mechanical system will work, and they are wary of anything that is outside their field of knowledge. While they are hesitant, we feel there is enough evidence that it will work.”
Hansen said he is confident the system will be a benefit and is anxious to get it built.
“I’m not afraid to be on the point of the spear. We’re always looking for new technology and the most efficient means of doing things. This engineered wetland is our way,” Hansen said.
Hansen said he does acknowledge the disadvantages the system has, and the city is planning to compensate for the inefficiency of wetlands in cold weather providing storage and reduced flow during the winter months.
Additional concerns with mosquito control have also been discussed, Hansen said, and the city plans on taking measures to reduce that problem.
Hansen said the city plans to construct the wetlands just northwest of its current lagoons on land it already owns. An additional 150 acres of land for storage facilities will be purchased with money the city received from a federal grant.
Thompson said the Parks and Recreation Department is participating in the project to provide trail systems and areas for bird watching because the wetlands will provide additional wildlife habitat in the valley.
“This is a green approach, not a mechanical approach, and there are examples of this type of thing working naturally. Water from the Bear River runs through a wetland before entering Bear Lake. That’s why it is so clean. If a mechanical system fails there is major environmental damage. If ours fails, there will be a bit more ammonia. It’s a win, win, win situation,” Thompson said.