AWWA MTC53816

The City of Georgetown, Texas located approximately 40 miles north of Austin,Texas has experienced tremendous growth over the last ten years. Since 1990,Georgetown's population has more than doubled from 15,000 to nearly 33,000 in theyear 2000. This growth is projected to continue at a rate of approximately sevenpercent per year. As the population grows in the community, so does the demandfor water and wastewater services. Due to the population growth, the City neededan expansion to meet projected water demands before the summer of 2000. CampDresser & McKee (CDM) was retained by the City of Georgetown to determine a meansof revitalizing the existing Southside Water Treatment Plant (WTP) in order togain additional capacity in their water system. The Southside WTP was constructedin 1983 and receives its water from the Edward's Aquifer. Historically, thegroundwater was pumped and chlorinated prior to being stored in an on-siteclearwell. Because this water is considered "groundwater under the influence ofsurface water", the Southside WTP was taken offline by the City in order tocomply with the requirements of the Surface Water Treatment Rule (SWTR). Theserequirements include filtration and inactivation of viruses and Giardia by acombination of conventional treatment and disinfection. The existing SouthsideWTP site is slightly over 1.2 acres and already contained a 1-MG clearwell andhigh service pump station. These existing site facilities provided little roomfor large process structures or sludge processing facilities, and no room wasavailable for large evaporation ponds. It was critical that the wastewater flowsgenerated from the technology chosen to revitalize the Southside WTP not produceexcess burden on the wastewater collection system. It was also necessary to limitthe wastewater flows of the plant to minimize the cost for disposal in thewastewater collection system. Due to on-site space limitations and the need tominimize wastewater flows, the selected treatment process had to have a smallfootprint with high recovery rates. It was also critical that the technologychosen would not limit the ability to complete the project by summer of 2000,including time for bidding, award and construction. Due to all of these factors,the City/CDM decided to explore low-pressure membrane systems as a viabletreatment technology. The City/CDM began pilot testing low-pressure membranetechnologies at the Southside WTP in January 1999 to determine optimal fluxrates, backwash frequencies and durations, chemical dosages and whetherirreversible fouling will occur. The results of the pilot study were verypromising; however, the results are not intended to be part of this paper and areonly briefly discussed. Based on the pilot study results, the City/ CDM initiateda high tech selection process to select the membrane equipment best suited forthe project. Following the selection of membrane equipmentmanufacturers--Aquasource North America (AquaNA), CDM began the design phase ofthe project in July 1999. Includes 3 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

05/01/2001

Number of Pages:

13

File Size:

1 file , 400 KB