Walnut Creek Water Reclamation Facility: “as good as it gets in the sewer business” - Authority doubles plant capacity, enhances operations with completion of Phase II

August 27, 2012 by Chris Wood, Ph.D.

The HCWSA Walnut Creek Water Reclamation Facility campus includes (pictured left to right): three aeration basins and four clarifiers, the electrical building (center) and the operations/laboratory and administrative buildings. <P>The consensus among those working at the new and improved Walnut Creek Water Reclamation Facility in southern Henry County is quite simply: “this is as good as it gets in the sewer business.”&nbsp;</P> <P>Since the Henry County Water &amp; Sewerage Authority (<span class="caps">HCWSA</span>) completed Phase II of expansion at the facility earlier this year, the Walnut Creek Plant is among the most technologically advanced and environmentally friendly facilities of its kind in the state of Georgia, say Authority officials.</P> <P>With the Walnut Creek Phase II expansion now done, the Authority has doubled the plant’s sewer treatment capacity for <span class="caps">HCWSA</span> customers from 4 to 8 million gallons per day (<span class="caps">MGD</span>), while improving the quality of biosolids and treated effluent leaving the plant to be recycled – as a soil amendment for the solids or via spray irrigation of the effluent onto protected green space, respectively.&nbsp;</P> <P>In addition, the expanded Walnut Creek Plant provides added operational flexibility for the <span class="caps">HCWSA</span> – enabling the Authority to take another wastewater plant off-line for maintenance, as an example – in addition to providing enhanced services for customers.&nbsp; As evidence, sewer originating as far north as Eagle’s Landing in Stockbridge can be treated at the expanded plant in the southern end of the county, thanks to proper long-term planning of capital improvements by the <span class="caps">HCWSA</span> that included an impressive collection system and a 48-inch interceptor sewer line that accompanied the Walnut Creek project.</P> <P>“Besides the obvious benefit of doubling our treatment capacity as a result of our second phase of construction, the Walnut Creek Plant and its <span class="caps">ATAD</span> process creates what Georgia <span class="caps">EPD</span> refers to as sludge that qualifies as a ‘soil amendment’ with beneficial reuse,” says Pat Hembree, <span class="caps">HCWSA</span> Division Manager overseeing water production and wastewater treatment.&nbsp; “Walnut Creek features a more advanced form of treatment and what we think will be required of sewer systems in the future, so this facility reflects our attempt to stay ahead of the regulatory curve in our industry.”</P> <P>Walnut Creek is categorized in the water and sewer profession as a contact stabilization plant, which also features an advanced odor control system and back-up generators to assure operations continue even in the event of a power outage.</P> <P>On the perimeter of the plant campus is the Influent Pump Station, which directs sewer flow to the Influent Splitter Box and then to the Pre-Treatment Unit, “where the games begin,” says Jimmy Thurmond, engineering consultant with <span class="caps">ARCADIS</span> who oversaw the Walnut Creek construction project on behalf of the <span class="caps">HCWSA</span>.</P> <P>Influent sewage then passes through a series of aeration basins (one has been added to the two existing as a result of Phase II expansion) and clarifiers (now totaling four with the addition of two new structures).&nbsp; The treated wastewater eventually flows into either of two holding ponds (the second one was added during Phase II), which total 88 million gallons of storage capacity, prior to spray irrigation on more than 1,000 acres of protected green space.&nbsp;</P> <P>The waste activated sludge (the solids during wastewater treatment) is separated for further treatment through autothermal thermophilic aerobic digestion (<span class="caps">ATAD</span>), which produces Class A sludge that is pathogen free and able to be used safely as a soil amendment or fertilizer in agriculture.</P> <P>Not only is the <span class="caps">HCWSA</span> Walnut Creek Plant one of only two wastewater treatment plants in Georgia to feature the <span class="caps">ATAD</span> process, according to Authority officials, the facility has received high praise from regulatory agencies because of its environmentally sound operations aimed at compliance in the future as well as what is minimally required today.</P> <P>The <span class="caps">HCWSA</span> Walnut Creek Water Reclamation Facility received a Gold Award from the Georgia Association of Water Professionals (<span class="caps">GAWP</span>) during the organization’s recent Spring Conference and Expo in Columbus, for attaining 100 percent permit compliance during 2011.&nbsp; The plant operated without a permit violation for the entire year – a measure of performance excellence within the industry.</P> <P>More information on the Walnut Creek Water Reclamation Facility, as well as a photo gallery of the plant’s highlights, is available online at <A href="http://www.hcwsa.com/" _mce_href="../../">www.hcwsa.com</A><p>.</P></p>