Building a new water treatment plant in Oak Ridge or renovating the current one could cost between $43.1 million and $46.9 million, according to an evaluation prepared for the city by an engineering company.
Three alternatives for renovating the existing water plant or building a new one were presented to the Oak Ridge City Council in October in an evaluation by Jacobs Engineering Group. The three options have different impacts on the raw water intake on the Clinch River in south Oak Ridge, an intermediate pump station at the Y-12 National Security Complex between the raw water intake and the existing water treatment plant, and the current 70-year-old plant, which is on Pine Ridge above Y-12.
The first alternative, which could cost $46.5 million, would rehabilitate the existing plant. It would continue to use the raw water intake, the intermediate pump station, and the water plant. It would include work at those three sites, as well as to the two underground lines that feed the water plant.
The rehabilitation would require mechanical and process equipment upgrades, pipeline replacement, electrical improvements, and slope stabilization.
The Jacobs evaluation said the building and basins at the existing plant are in good condition, and the facility works well at 8-12 million gallons per day. It has the two underground lines coming in and three going out, and two storage reservoirs on Pine Ridge, one of three million gallons and the other of four million gallons.
But it has aging mechanical equipment and an electrical system that doesn’t meet current code.
“It was supposed to be temporary,” Oak Ridge Public Works Director Shira McWaters said Thursday, referring to the 1940s-era plant.
There are also geotechnical issues including an undermining of filters and areas that require slope stabilization, including around the water storage reservoirs.
The existing plant can produce 28 million gallons of water per day. It uses conventional technology that has been around since the 1800s—officials said the plant has big sand filters, among other things—and it was built between 1943 and 1945 and expanded in 1955.
The plant is not in imminent danger or expected to fail, but there is an increased cost of repairs associated with aging facilities, McWaters said.
The water treatment plant provides water to the City of Oak Ridge, including residents, businesses, and some federal facilities; Oak Ridge National Laboratory; and Y-12.
There were questions raised earlier this year about whether Oak Ridge and the U.S. Department of Energy should continue to invest money in the water plant, build a new one at a new site, or consider other alternatives.
“It’s critical,” McWaters said Thursday. “It’s our sole source of water.”
The second water plant alternative presented to City Council in October could cost $46.9 million. It would build a new membrane-system water treatment plant capable of producing 16 million gallons per day at the intermediate pump station at Y-12. It would still use the raw water intake on the Clinch River and require work at the first two sites (the raw water intake and the intermediate pump station), along the water lines, and slope stabilization around the existing water storage reservoirs on Pine Ridge.
Water would still be pumped up the hill to Pine Ride for storage. There is not enough room at the intermediate pump station for water storage, McWaters said.
The membrane-system water treatment plant could be expanded. Membrane plants use compact cartridges that McWaters compared to straw-like tubes with tiny holes, almost like minute sieves. They can be “sized down” to capture viruses, she said.
McWaters said the conventional process used by the existing water treatment plant is slower and requires a larger “footprint.”
There is aging equipment at the pump station also. It has five 1950s-era pumps that are not made anymore. The city has had to “cannibalize” the pumps, and they run on 2,400 volts, although 480 volts is now the standard, McWaters said.
The third option would also build a new membrane treatment plant capable of making 16 million gallons of water per day, but at the water intake on the Clinch River. That option could cost $46.5 million, the Jacobs Engineering evaluation said. This third alternative would eliminate work at the other two sites, but new water lines would be required. This plant could also be expanded, and it would be a secure, efficient single site, the Jacobs evaluation said.
Water would no longer have to be pumped up the hill to Pine Ridge and energy costs would drop, but money would have to be spent on new piping, including to connect to federal facilities.
On Saturday, Oak Ridge City Manager Mark Watson said the city could install variable-speed electric pumps at the raw water intake, and that would save electricity and reduce carbon emissions. But that would require changing a 2,400-volt substation, a switch that could cost several million dollars, Watson said.
He said officials hope to put the Jacobs Engineering evaluation into final form by Thanksgiving and then develop a strategy, including in discussions with the U.S. Department of Energy and its various branches.
“We’ll try to take it forward,” Watson said.
The city would seek to split the costs with DOE. The current consumption and shared costs are split 50/50, Watson said.
“It’s a big ticket for both parties,” Watson said. “That has an impact on our people.”
He said it’s too early to say which alternative the city staff prefers.
Watson said the current plant is working, but it was built before there was an Environmental Protection Agency, Clean Water Act, or requirements for water quality. And water quality measurements have gone from parts per million to parts per billion, he said.
The world-class lab in Oak Ridge (ORNL) needs high-quality potable water, Watson said.
Discussions about the future of the current plant came up earlier this year as the city and DOE negotiated a contract extension for water supplied to ORNL and Y-12.
It’s not clear yet how the rehabilitated or new plant would be financed. Rehabilitating the existing plant on Pine Ridge would include about $10 million to $12 million for slope stabilization.
“That’s been one of our fears,” Watson said.
The current plant produced, on average, 7.8 million gallons per day in 2015, down from 10.9 in 2005. Its peak day was 12.2 million gallons on February 22, 2015.
Oak Ridge and much of its infrastructure, including the water plant, were built during World War II as part of the top-secret Manhattan Project, the frenzied effort to build the world’s first atomic bomb—before Germany could.
The water treatment plant was originally built and operated by a DOE predecessor. DOE gave the plant to the city about 16 years ago.
In a March 31 memo to Watson, McWaters said about $7.2 million has been invested in several major and minor projects since the City of Oak Ridge took over the operation and maintenance of the water treatment facility, and it is not known what additional long-term capital investment is needed to keep the plant operating.
Among the problems cited at a March 29 special meeting is a leak of about 3,000 gallons per day. At the time, the city staff said it was not sure where the leak originated or whether the water that is leaking has already been treated.
The city staff said then that there is also some slope instability at the ridge top water plant site that could affect access and erosion. That doesn’t make the plant unusable, but it could add to the cost of renovations, McWaters said.
McWaters said at the time that the 70-year-old water treatment plant continues to show signs of aging despite efforts over the last 15 years to modernize and upgrade, and “many of the plant’s assets are near or have exceeded their useful life cycle and require replacement or major rehabilitation.”
City officials have said bringing the existing plant up to code could cost $16 million or more. They said the plant has been modernized and updated, including in its control systems. They said the plant provides excellent water that meets water quality standards and exceeds standards. But they said some of the plant’s current problems could affect its long-term viability.
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