Adding fluoride costly
Thursday, October 27, 2011
By Kathryn Lucariello Carroll County News
EUREKA SPRINGS — Citing preliminary cost estimates, Brad Hammond and Chris Hall of McGoodwin, Williams & Yates engineering firm told the Carroll-Boone Water District board Thursday that implementing state-mandated fluoride additive to the drinking water supply could cost around $1.27 million.
Hammond said their fluoride study was 90 percent complete, and they are waiting on supply prices.
The two did a presentation which looked at recommendations for the number of dispensing facilities, the type of fluoride to be used and cost.
Comparing building one injection facility versus two, Hammond said one facility would be cheaper and require less operator time, but would require injection in the water transmission line below both the east and west plants and would need two injection points, increasing “operational complexity.”
The two-facility option would have a separate building at each plant with fluoride added to the clearwells and would allow for easier monitoring with equipment already in place. The cost would be higher, however, and it would increase operator time.
“The actual feeding takes a few minutes, but operators need to wear special clothing. It will be dusty, so they’ll need masks,” Hammond said. “That would be the only time of day they’re in that building.”
He said he, Hall and the Carroll-Boone staff had toured the Beaver Water District fluoride plant and received helpful information, mostly about the building. McGoodwin, Williams & Yates engineered the Beaver fluoride plant years ago.
Of the three types of fluoride available for drinking water, fluorosilicic acid liquid, sodium fluoride powder and sodium fluorosilicate powder, they were recommending the third for several reasons.
Although it has less available fluoride (61 percent as opposed to 79 percent for the liquid), it has far less solubility (.0762 grams per 100 milliliters versus an infinite amount for the liquid form).
“The less soluble it is, the harder it is to overfeed it,” Hammond said, which increases its safety.
Although Hammond had not yet identified suppliers or country of origin for the fluoride, he said of the three types, sodium fluorosilicate powder has 98 to 99 percent commercial purity, with the liquid at 20 to 30 percent.
It is also the most economical of the three and is the one used by the Beaver Water District, which switched over from using the liquid years ago after fumes from the liquid severely damaged the injection facility.
The powder comes in 50 lb. bags, he said, and the district would probably go through about two bags per day at the west plant.
He gave recommendations for size and locations of the buildings as well. Each building would have enough space for the mixers, waterlines and pallet storage.
A breakdown of total project cost, which Hammond stressed is only an estimate at this point, shows $20,000 for site work, $380,000 for the east plant, $230,000 for the west plant, $280,000 for the feeder equipment, $30,000 for yard piping and a possible $330,000 for engineering and contingencies, which add up to $1.27 million. Hammond could not break down the actual engineering cost, apart from contingencies, he said.
“If the Arkansas Natural Resources Commission funded this, they usually allow about 10 percent for engineering design and another 8 percent during construction, so probably 15 to 20 percent. But I hate to use percentages because they may not be accurate.”
He said annual cost of the fluoride itself would probably be about $20,000.
The $280,000 equipment cost is all that would be funded by Delta Dental, who offered to fund equipment for any drinking water supplier in the state having to add fluoride under the mandate. The district would bear the remainder of the cost.
He said he and Hall will return when they get estimates from equipment manufacturers.
In other business, the board:
* Approved the 2012 budget, with a 3-percent, across-the-board payroll increase for all staff. Office Manager Jim Allison reported a record year of water sales, even though production costs were also increased because of spring flooding and summer drought.
* Heard Plant Manager John Summers report 1.5 million gallons of sludge have been removed from the sludge ponds so far this year and that total cost will probably run around $68,000. It is applied to fields in Garfield at no cost to the district.
* Heard Hall report the engineers recommend holding off on building the Kings River crossing parallel waterline and instead focus on replacing a 200-foot section of 24-inch line with 36-inch line where the Highway Department is planning the Green Forest bypass. more efficiently.