US Nitrogen Treatment Plant Detailed

By Walter F. Roche Jr.

US Nitrogen, the Greene County chemical company, says it projects a water treatment plant on its Midway site will generate as much as 44 dry tons of sludge per year and it would prefer to dispose of that waste on nearby agricultural land.
The new details on the water treatment facility were included in a plan filed this week with the Tennessee Department of Environment and Conservation. State officials had set a July 31 deadline for a revised plan in a notice of violation issued in February.
The US Nitrogen filing contains previously undisclosed information on the treatment plant including five holding or storage ponds located across the railroad tracks from the chemical manufacturing facility. According to the filing the treatment plant is actually owned by the Industrial Development Board of Greeneville and Greene County, but operated by US Nitrogen under an agreement between the two parties.
The treatment plant is used to remove impurities from the millions of gallons of water the company pumps free of charge from the Nolichucky River. The purified non-potable water is then used as boiler feed water in the manufacturing process for ammonium nitrate and for cooling towers required in the manufacturing process, the filing states.
The cooling tower water, the company reported,is "recirculated through the evaporative cooling towers and treated with various chemicals."
The 15,000 square foot treatment plant is located on West Seven Springs Lane approximately two miles from the intersection of U.S. Highway 11E and I-81. The plant "conveys and discharges to the river the effluent generated by the IDB WTP (treatment plant)and process related uses of water at US Nitrogen."
The company plan, submitted by US Nitrogen plant manager Andrew Velo, states, "The IDB WTP (treatment plant) process uses multiple processes and chemical additives to produce non-potable water from water withdrawn from the river."
Those processes also produce the sludge which is then pumped into two settling ponds, each capable of holding 315,000 gallons. On site there are also two effluent storage ponds with a capacity of 1.5 gallons apiece and a raw water pond, with a 7.5 million gallon capacity, the company reported.
"As needed," the plan states,"US Nitrogen will remove the sludge from the settling ponds. Based on initial dredging, the filing continues, "the quantity of sludge removed per each event is 61 wet tons or 11 dry tons."
The company told TDEC it expected each of the settling ponds to be dredged once per year, each producing 4,000 cubic feet or 11 dry tons.
"This process will help to identify any additional pre-treatment standards that must be met for the disposal of beneficial use of the sludge.
The plan offers two sludge disposal options. One would be "beneficial" placement on nearby agricultural properties while the other would be disposal in a landfill.
"To the extent practical, US Nitrogen will seek to beneficially use sludge rather than dispose of it as waste," the plan states.
In fact the company already has submitted a permit application for the "beneficial use" disposal method to TDEC' Division of Solid Waste Management.
The plan calls for samples of the sludge to be tested and "sampling activities will be conducted to ensure that sample data are representative."
"In the event beneficial use is not available, US Nitrogen will dispose of de-watered sludge at a permitted solid waste landfill in accordance with applicable regulations," the plan states, adding that the sludge would be stored temporarily on plastic sheeting.