Ultrafiltration System Helps Oklahoma Town Meet Regulations

Facing aging infrastructure and more stringent drinking water regulations, the city of Pauls Valley, Okla. undertook a rigorous pilot testing program to establish design parameters for a new water treatment plant which would achieve compliance for turbidity, pathogen and organic removal.

Evoqua Water Technologies was contracted in October 2008 to provide a 4.5-mgd Memcor CS ultrafiltration system, designed for future expansion to 6 mgd. The Memcor system acts as a final filter after flocculation and tube settling. The flocculation step is designed to provide organic removal along with some turbidity reduction. The ultrafiltration system was designed to remove all solids greater than 0.04um, including Cryptosporidium and Giardia.The Memcor CS system provided the city with a flexible, automated system able to verify particulate removal using an automated direct integrity test as presented in the Membrane Filtration Guidance Manual (MFGM) in order to meet the to meet the Long Term 2 Enhanced Surface Water Treatment Rule. In addition to a verifiable barrier to pathogens, the CS ultrafiltration system provides consistent product turbidity exceeding the standards set by the drinking water regulations.

As part of the system supply, Evoqua included a MemSAP rail-driven access platform, which enables safe and easy maintenance in the event membranes need to be accessed. The MemSAP allows building designers to eliminate the overhead bridge crane required by some submerged membrane systems, which reduces the height requirement and cost of the treatment building. This allows the city to fully realize the system's benefits.

In September 2010 the plant began producing water and operates between 3 to 4.5 mgd based on their demands.

“The plant has met or exceeded expectations in all areas including reducing THMs, HAA5s and bringing the city into compliance with the newer more stringent requirements for producing water,” said James Frizell, city manager of Pauls Valley. “The city is has been very satisfied with the results of the operation and the overall quality of the water that the Memcor CS membrane plant produces.”