Siemens Water Technologies has been awarded an $8.45 million (6,25 million euros) contract by Archer Western Contractors to expand the Scottsdale Water Campus Central Arizona Project (CAP) drinking water treatment plant. Archer Western is a general contractor working for the City of Scottsdale, Arizona. Siemens will supply a 30 million gallons per day (MGD) (113.5 MLD) system that uses the latest Memcor CP membrane technology. The project is scheduled for completion in early 2009.

The Scottsdale Water Campus presently consists of a 12-MGD (45.4 MLD) water reclamation plant and a 50-MGD (190 MLD) drinking water treatment plant. The reclamation plant uses a Memcor PP (polypropylene) membrane system, installed in the late 1990's, as pretreatment to reverse osmosis for treating wastewater that is then used for both aquifer recharge and irrigation. The drinking water treatment plant has been using media clarification to treat surface water from a canal. This plant needed to be expanded because of increased demand for drinking water in the North Scottsdale area. Today, the city of Scottsdale has a population of 240,000. In the last 10 years, the population has grown by about 35 percent.

For the drinking water treatment plant expansion, the Scottsdale Water Campus considered several different membrane technologies. After a successful 100-day pilot test was conducted at the site, the City of Scottsdale chose the Memcor CP system for its effluent quality, lower installed cost and ease of expandability.

The Memcor CP system, introduced by Siemens in June 2006, uses 1.8- meter PVDF (polyvinylidene fluoride) membrane modules, which increase the filtrate capacity by over 50 percent, compared to the earlier generation Memcor membrane modules. The CP system provides greater than 4-log removal of Cryptosporidium, Giardia and bacteria, and over 1.5-log virus rejection, regardless of changing feed water conditions. Its compact, modular design allows the system to be easily modified and expanded, and takes up roughly 70 percent less space than conventional water treatment systems.

The system expansion at the Scottsdale Water Campus will initially consist of seven Memcor CP units, each containing 324 modules, with the building designed to accommodate a total of ten units, bringing the total design capacity of the expansion to 45 MGD (170 MLD).