Early in 2003, the City of Rome, Georgia, decided to upgrade their Blacks Bluff Waste Water Treatment Plant screening equipment. The challenge at the site was that the design at the headworks section of the plant had two levels. Thus, the new design would require extremely long screens which would allow the screenings to be collected below ground level and then transported up to the street level.
Once the City decided on expanding the plant with a new headworks facility, the next step was to determine which screen manufacturer could provide a design which could effortlessly screen the wastewater from one level to the next. After evaluating different supplier’s equipment and various site visits to inspect their installations and view exactly how they would fit into the City of Rome’s facility, the client selected the Headworks Bar Screen. Atlantic Skanska, Inc. was awarded the purchase order as the contractor and in the fall of 2006 the two mechanical bar screens were started up.
The overall length of these screens ended up to be 55 feet (17m) long with a channel width of 4.5 feet (1.4m). Each screen is rated at 27 MGD (1.2 m3/s). As was relatively common back in the early 2000s, the bar spacing selected by the City’s engineers was 2 inches. The screens have performed virtually trouble free to the complete satisfaction of the owner since start-up.
The unexpected challenge for the plant was that the choice of the wide bar spacing of 2 inches allowed relatively large objects such as crushed plastic bottles to pass through. These objects eventually blocked the blow down valve of the grit system which resulted in costly maintenance. Therefore, the client chose to upgrade the screens to a finer bar spacing of a 1/2 inch wide spacing. It was decided to upgrade one screen per year.
The first screen was easily retrofitted in 2015 with finer bar spacing. All of the necessary components were delivered by Headworks to the site in the form of a simple kit. During the upgrade, the screens were found to be in excellent condition and did not require any other repairs or parts replacement. Notably, the lower bearings and sprockets have continued to hold up even after nearly 10 years of operation. (See last month’s February 2016 HeadsUp Article Ignore the Rumors – How Long Does a Headworks Sprocket Really Last for another example of long lasting below water sprockets in Kearney, New Jersey.) The order for the second Headworks Bar Screen retrofit kit is already underway.
Johnny C. Massingill, the WRF Director of the City of Rome stated his satisfaction about the units as follows:
“If there was a better bar screen out there, we would buy it. We could have bought another screen when we decided we needed to remove more debris than the 2 inch screens were designed to do, but retrofitted the Headworks to ½ inch screens instead. We like the dependability and durability of the screens, and the retrofit was relatively easy because we could remove the screen and do all the work on the deck rather in a 50-foot deep hole. The dual speed of the screens also eliminated any head loss concerns we had with going to a smaller gap.”
Are you contemplating a retrofit of your screening facility and want to protect your plant, reduce life cycle costs and lower operator personnel interference? Contact one of our stellar Headworks Sales Engineers at firstname.lastname@example.org or +1-713-647-6667 or your local Headworks Manufacturers Representative.
Image credit: "Confluence of the Rivers," Ron Jones © 2000, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/