EDITOR’S NOTE: This is the second of a two-part series on Piqua’s water supply and new Water Treatment Plant currently under construction.
PIQUA — With a current Water Treatment Plant built in 1925, the city of Piqua is stepping up its game when it comes to treating and removing organic material from the water with its new Water Treatment Plant currently under construction.
The city of Piqua operates off of surface water supplies versus wells. In addition to the Great Miami River, the city has two other water sources, the hydraulic system that includes the canal and lakes along with the quarry on Piqua-Lockington Road. The water at the quarry is partially spring-fed and also comes from the river, but the rocks at the quarry clean the water naturally.
“We’re building a new water treatment plant because the newer EPA requirements can’t be met at the existing 90-year-old plant,” Piqua City Manager Gary Huff said. “Plus it is crumbling and coming apart, so that’s the reason we’re under construction with the new plant.”
“A lot of that stems on the disinfectant byproducts side of compliance,” Piqua Water System Superintendent Don Freisthler said. “The current technologies that we have in the old plant aren’t as efficient at removing organics.”
Freisthler explained that the disinfectants byproducts are formed in the distribution system “when the chlorine stays exposed to organic material in the water.” That material includes things like decaying leaves and algae.
When the remaining chlorine molecules — or other disinfectants used to control microbial contaminants — react with organic material found in the water, they can form byproducts of organic chlorinated chemical compounds called trihalomethanes. The EPA regulates total trihalomethanes (TTHM) at a maximum permissible level of 80 parts per billion (ppb). During the city of Piqua’s third quarter testing of the water in 2015, the city exceeded that limit by 1 ppb.
“We have four sites that we monitor throughout the city,” Freisthler said. “One of the sites we monitor is considered maximum resistance time or the longest time the water can be exposed to the organics. At that location, we exceeded by one part per billion and that put us in what’s considered a noncompliance status for that location. In fact, it puts the entire city in. Up until last year, we could average all four sites, and if we were still able to do that, we would have been in compliance.”
The site where the city exceeded that maximum was also far away from the Water Treatment Plant, so the water was in the distribution system longer.
“This is one of the reasons the EPA told us in 2006 that they felt our current facility was not going to be able to continue to meet these regulations and so at that point is when we decided and had it evaluated that we had to have the new facility,” Freisthler said.
In the updated East Ash Street water tower, Freisthler explained that there was “a mixing and spray aeration system that was installed in that tower that will (assist) in removal of the disinfectant byproducts that are formed out in the system.”
In December 2015, the city’s fourth quarter testing showed that the city did return to compliance status for all four locations. Piqua Water System Assistant Superintendent Bob Jennings stated that the TTHM levels dropped by approximately 50 percent in December 2015 testing.
“Typically, we see our higher numbers in that third quarter, anyway, because that’s later summer going into early fall,” Jennings said. “You have more organics in the water, the heat from the summer, all of that is a factor that contributes to that. “
The new Water Treatment Plant will also be able to incorporate new technology that will assist in removing organic material from the water to further fend off disinfectant byproducts.
“At the new plant, the new technology will have granular activated carbon filters,” Jennings said. “And just with the layout of the current plant, we looked at ways to possibly run our water through that and there was just no feasible way that we could do it at the current facility. We even looked at the possibility of bringing in a semi-trailer with the filters on it, and it just wasn’t feasible to it. So the new plant will that have technology. And those filters will help greatly in removing the organics out of our water.”
The granular activated carbon filters will also be the best available technology to remove any cyanotoxins, which are toxins released when harmful algae or a harmful algal bloom dies.
“There’s no one exempt to harmful algae bloom, so it could happen to Piqua,” Freisthler said. “Also, we (were) fortunate to get a state EPA grant and we’re able to test for the algae … microcystinswithin our water and last year we tested every week and we had no detection of that present in our hydraulic system.”
“Right now the testing is not mandated by the EPA but … in 2017, it will be mandated that we test every week,” Jennings said. Freisthler added that testing for cyanotoxins will be required starting in July 2016.
“So our new plant, we’re kind of … going to be ahead of the game anticipating those new requirements and the new plant should meet those requirements,” Huff said.
Huff explained that the city will not have to go back to make adjustments to the plant because of those upcoming requirements.
Due to having multiple water sources, the city’s water is still safe even if a potential harmful algal bloom were to form in the hydraulic system as the city can isolate that water source and draw from the other sources instead.
“The other thing that’s nice is with us having three separate sources, if, let’s say we would see that we were having a bloom within the lake, we can isolate that source and get water strictly from the river until we were able to sure that bloom was gone,” Jennings said. “So we have that luxury … or capability that we can set that source down and go to a different source before if we see a bloom starting.”
Jennings said that the city is also looking at purchasing a sonde to help the Water Treatment Plant monitor changes in the lake, such as changes in the water’s pH levels.
“And if we can see a change in the pH in the lake water, then we’ll know that there’s the potential for a bloom there and it’ll give us even a little bit more heads up on that,” Jennings said.
The new Water Treatment Plant will also have specific areas for specific chemicals to be applied to the water. At the current plant, all of the chemicals are applied in one spot. Freisthler explained that each chemical added to the water needs its own time to complete its reaction to get the maximum efficiency out of that chemical reaction. The city will be seeing that at the new plant.
“Each chemical we apply at the new plant has a certain amount of detention time to allow the fulfillment of the chemical reactions and so each one will do a better job at removing these excess organics to assure that we have a better quality water,” Freisthler said.
The city will also be using new products to treat the water, some of which are safer and more effective.
“We’ll be using a product called sodium permanganate, which is a better oxidizer, and we can use it because of the ability to have the reaction time we need,” Freisthler said. “We’ll also be eliminating gas chlorine for disinfection.”
The city will, instead, be utilizing sodium hypochlorite. “That’s liquid chlorine very much like what people disinfect their swimming pools with or what you use in your laundry at home,” Freisthler said. “Only a very high concentration.”
“It’s a much safer product than the chlorine gas,” Jennings said.
The new Water Treatment Plant is taking up approximately 20 acres of about 40 acres of available land.
“It’s (being) built in a manner that we can add to it,” Piqua Director of Utilities Dave Burtner said. Burtner explained the construction is on schedule and that the city is very satisfied with their contractor Peterson Construction. The city’s engineer for the project, CDM Smith, also has two representatives on site at all times.
Reach reporter Sam Wildow at (937) 451-3336 or on Twitter @TheDailyCall