The Tri County Alliance, an economic development board, was promoting a new Advanced Technology Business Park at a former DOE facility. Infrastructure improvements were required to attract new businesses. The existing wells had elevated levels of iron and were very aggressive in nature with extremely low pH and alkalinity. The new treatment plant was designed to eliminate the iron as well as stabilize the water supply. The Engineer worked with Tonka Water to pilot and design South Carolina’s first Dualator® VI treatment plant.
The 1,000 GPM treatment process consists of three steps in one compact system: aeration, detention, and filtration. The aeration step is for gas stripping and iron oxidation. Due to the low pH and alkalinity, the raw water is very aggressive; therefore lime and sodium bicarbonate are added after aeration for water stabilization. The detention tank allows full oxidation of the iron and ensures complete chemical reactions take place prior to filtration. The final step is filtration through a four-cell filter system using a dual-media filter bed of silica sand and anthracite. The anthracite cap serves to capture the larger iron particles and precipitates, while the silica sand removes the smaller solids that pass through the anthracite.
The system is controlled by Tonka Water’s PLC-based automatic control panel with an interface touch pad. Another benefit of the Dualator® VI treatment plant is that it uses in-service backwash, thus it requires no additional water source for backwash supply.
This raw water analysis reflects a very aggressive water with iron that is above the MCL. Since start-up, the treatment process has been highly effective in delivering quality water as indicated below.
|Iron (Fe)||0.35 mg/L||0.01 mg/L|
|Alkalinity||1 mg/L||42 mg/L|