The design for John Day’s new wastewater treatment plant has been given a green light, and there is a clear path forward for construction of a facility that will produce Class A reclaimed water, City Manager Nick Green announced March 12.
In some ways, the project is the most critical to the city and the linchpin to other projects related to developing 83 acres of city-owned brownfield property along the John Day River — including even a possible restoration project aimed at returning the river channel to a more natural condition while reducing flooding concerns.
The design for the wastewater treatment plant was approved that very same day by the Oregon Department of Environmental Quality, Green said during a special meeting at the Grant County Regional Airport. The council unanimously approved a resolution adopting a 2019 wastewater facilities plan update supporting the new plant.
Green noted that the new treatment plant will take up 1 acre versus the 30-plus acres currently occupied by three sewage lagoons and a 70-year-old mechanical treatment plant. The lagoons are not the best use for riverfront property, Green said.
The city will pursue $11 million in grants and loans to pay for construction of the facility, Green said. Construction could begin in spring 2020.
The Anderson Perry engineering firm in La Grande has been studying the project for 12 years, senior engineer Brett Moore said. The deteriorating condition of the aging facility and newer, more stringent environmental regulations add to the difficulties.
A significant geographic hurdle is the steep terrain that confines the cities of John Day and Canyon City, but there are also numerous bureaucratic hurdles, he noted.
The new plant will produce more Class A reclaimed water than can be utilized by the city, especially during winter. There were concerns that dumping the warmer treated water into the river could adversely impact the total maximum daily load for temperature, Moore explained.
A recent court decision on TMDLs, however, has created confusion for the state and federal agencies that will determine regulations for the new plant, Moore said. In a nutshell, the agencies currently lack the information and framework to make a decision on the new plant’s operation, he said. A temporary agreement has been reached allowing the city to dump the Class A reclaimed water into the existing lagoons, Moore said.
Moore also described a state law requiring new treatment plants be sized by official population estimates, which for John Day and Canyon City are negative. Asking a city to make a large investment in a plant that will not accommodate growth is unrealistic, he said, and Anderson Perry continues to debate this issue with state officials.
It will take about two years before the wastewater treatment plant is operating. That’s enough time to complete design and permitting work for a plan to rework decades of gold mine dredging disturbance and restore the John Day River to a more natural condition, according to Gardner Johnston, a hydrologist with Inter-Fluve of Hood River.
Johnston presented an aerial photo illustrating the extent of dredge tailings covering much of the John Day city area in 1939. He said he was unable to find earlier photos or maps showing the original river channel, but he believes a normal meandering river was left in a straightened ditch when the miners finished.
That kind of channel does not allow for the seasonal flooding needed by riparian habitat and lacked the deep pools and shade needed by fish. The goal is to return sinuosity to the river and create a lower elevation floodplain along the north side of the river.
That area would flood seasonally but remain dry in summertime for trails and recreation.
Benefits would include reduced flood impacts to urban areas, new floodplain surfaces that would better mimic natural river conditions while providing multiple recreational uses, constructed wetlands that could be used for city stormwater treatment, improved access for fishing or recreation and enhanced values for neighboring properties.
Local resident John Morris asked if the slower-moving river water would get hotter in summertime without shade, and Mark Croghan, a hydrologist with the Bureau of Reclamation, asked about the stability of the new constructed channel during floods.
Johnston explained that channel design and revegetation would address temperature issues. He also acknowledged that the project was in an urban area and not a headwaters area, where a river could run wild. The project also will be designed to maintain the functionality of the diversion dam near the former Oregon Pine sawmill building, he said.
Inter-Fluve came up with the river restoration proposal based on the Oxbow project they had done on the Middle Fork of the John Day River, Green told the Eagle. The river restoration project would be paid for with external non-city funds, with estimates ranging from $2.5-3 million, depending on the scope of the project, he said.
Once approved, construction of 3,000 feet of meandering channel could be completed in one season or in phases, Johnston said. Green noted that unusual objects have been used for rip-rapping the river, including an automobile body.
Future work could include study and permitting for integrating rehabilitation of the sewage lagoons into the restoration project, a geotechnical study of the stability of subsurface gold dredging areas and a hydrologic engineering feasibility study.