John Day personnel met with representatives from the Anderson-Perry engineering firm and Sustainable Water last week and brainstormed for two days in the fire hall over concepts and goals for a new wastewater treatment plant.
The goal is not only to replace an aging treatment plant but to produce reclaimed water with economic value, Brett Moore of Anderson-Perry told the city council Nov. 14. Treated water that currently is dumped in four percolation ponds where it seeps into the ground could instead be used to grow hay or pasture, or irrigate the city’s golf course, parks or baseball fields.
It could also be used to grow produce in greenhouses for local consumption, be sold to Malheur Lumber for industrial uses or used to flush toilets at a hotel. A 100-room hotel uses about the same amount of water to flush toilets as 60 single-family homes, Moore said.
The state’s role
The city and consultants also met with the Oregon Department of Environmental Quality, Business Oregon and the U.S. Department of Agriculture to learn about regulations and standards as well as financing opportunities.
To assist small rural cities meet the requirements of the Clean Water Act and navigate complex financial arrangements, the DEQ developed the First Stop planning assistance program. The idea is to open discussion on “potentially approvable” alternatives, discuss funding sources, identify a specific interagency team to serve the city, set up a communications strategy between the agencies and follow up commitment assignments.
Daniel Allison and Eric Lohan traveled from Richmond, Virginia, to represent Sustainable Water. Established in 2010, the company develops, builds and operates wastewater reclamation plants across the United States, including plants in the colder climates of northern Wisconsin and Burlington, Vermont.
Allison told the Eagle that the DEQ and the other agencies were excited and supportive of John Day’s proposed project — at the technical and permitting levels. He said Scott Fairley, from Business Oregon, saw the proposal as a “positive job-making project.”
“The DEQ was glad to see John Day looking at innovative ways to handle wastewater management,” Allison said.
Allison and Lohan said the DEQ had well developed standards compared to other states, which showed that Oregon is prepared to see more wastewater reclamation plants built in the state.
An aging plant
John Day’s wastewater collection system began in 1948, with major additions in 1970 and 1978. Since then, it has been expanded several times and currently handles up to 240,000 gallons per day, or 87.6 million gallons per year.
The city contracted with Anderson-Perry in 2008 to develop a new wastewater facilities plan, and the city council approved construction of a new treatment plant at the same site after reviewing the plan.
Anderson-Perry estimated the cost of the new plant in 2011 at about $8.29 million, but according to City Manager Nick Green’s city council memo five years later, several assumptions about the plan no longer applied. The city’s population had declined, and emerging technology warranted an update to the plan, he said. On top of that, the DEQ did not issue a 10-year discharge permit for the existing wastewater treatment plant.
The plant “may be unable to meet future permit requirements for biochemical oxygen demand, total suspended solids and chlorine residuals,” Green said in an Oct. 14, 2016, application for a state feasibility study grant. “Therefore, water that is allowed to percolate adjacent to the John Day River has the potential at times to degrade the water quality of the river.”
The city was awarded the $50,000 grant, which will help fund a feasibility study estimated to cost about $110,000.
New type of treatment
Allison said a rough figure he’d heard for a new John Day wastewater treatment plant was around $10 million. A more exact figure depended upon what level of treatment was expected and how the reclaimed water would be used, he said.
He estimated that a 10,000-square-foot facility could handle John Day’s needs, with much of it enclosed in glass. Wastewater would run from one “reactor” to another — open-topped tanks with a plant rack on top. Wastewater to be treated would only contact the roots of the plants.
Each reactor would be different, and the building would resemble a botanical garden. Sustainable Water’s facilities have attracted more than a thousand tours, Allison said.
Among the plants that would be grown in the reactors include the umbrella plant (cyperus alternifolius), lilies from the canna species, taro (colocasia esculenta) and elephant ear (alocasia odora), Lohan said. These plants are not for consumption, but they require monthly harvesting as they grow quickly, he said.
Wastewater would first encounter a mechanical self-cleaning screen to remove nonfecal solids and then go to two outdoor reactors. The partially treated water would then go to two reactors in the greenhouse portion of the plant, followed by filtration to remove bacterial biomass that had accumulated in the process.
Lastly, devoid of nutrients, the clean discharge water would be disinfected in a two-step process by ultraviolet light and chlorine to ensure no regrowth of pathogens, Lohan said.
The treatment plant would be completely automated and controlled using internet-based software, Allison said. John Day’s state-certified treatment plant operator could run the plant, he said.
“The new plant will have less overall operational costs than the current plant, where crews are trying to maintain aging equipment,” Allison said.
Reclaimed water uses
While reclaimed water can be used to cool the treatment plant in summer, heat from the incoming wastewater would be used to warm the facility in winter. In addition to a generator for emergencies, the plant would have backup electric or gas-fired heaters to keep the plant warm on cold winter days.
But some demand for reclaimed water will cease during winter, including irrigation for farms or parkland and industrial uses from businesses such as Malheur Lumber. As a result, a storage reservoir might be needed to hold treated water in winter. A ballpark figure of 20 acres 7-feet deep was mentioned at the city council’s Nov. 14 meeting.
There are several classes of reclaimed water, but producing the highest, Class A, would provide the most options for reuse, Moore said.
Class A water would be the bare minimum for use in a greenhouse growing produce for human consumption, Lohan told the Eagle.
“The majority of use for reclaimed water is industrial,” Lohan said.
The city will look for long-term users, Green told the city council. With all the timber mill closures, Grant County has lost a lot of industrial demand, he said.
Human health risks
Potential contaminants in reclaimed water include microbial pathogens, heavy metals and “contaminants of emerging concern” — trace constituents from household products such as caffeine, insect repellent or cleaning chemicals, from personal use products such as antibacterial soap and toothpaste and from pharmaceuticals such as antibiotics.
A 2012 study by the National Research Council found that the risk of exposure to certain microbial or chemical contaminants from drinking reclaimed water did not appear to be any higher than the risk found in some municipal drinking water treatment plants.
Allison noted that drinking water systems in many U.S. cities routinely use river water downstream from another city’s wastewater treatment plant’s discharge pipe. In any case, John Day has no plans to use its reclaimed water for drinking water.
Water quality sampling is conducted five times a week for Class A water, Allison told the Eagle. But design of the John Day facility will depend upon the big picture, and what kinds of uses can be found for the city’s reclaimed water.
“Part of our challenge is to look at the project holistically — what are the most economical first steps?” Allison said.
Lohan said it was possible ground-breaking for the new plant could take place in 2020-2021, and the plant could complete commissioning and be fully operational by 2022. At that point, the current treatment plant could be shut down.