Challenge

Located on the Upper Peninsula of Michigan, the city of Marquette utilizes raw water from Lake Superior for its potable water needs. This source is of extremely high quality and previous treatment was not required. However, an administrative order to the city required a treatment facility be established.

Solution

Extensive pilot testing was performed over a period of six months. This showed that the MEMCOR® Continuous Microfiltration (CMF) was capable of producing high quality filtrate from extremely cold raw water. Temperatures ranged from a low of 0.5 degrees C to a high of 10 degrees C.

The city of Marquette, with the engineering consulting services of Fishbeck, Thompson, Carr & Huber, chose The Siemens Water Technologies MEMCOR® CMF for the following reasons:

• Cold water application
• Ease of operation
• Low operating costs
• High recovery rate
• Low operator training time
• Return backwash to Lake Superior
• Log 3 pathogen removal

In September of 1997, a MEMCOR® Model 8x90M10C system was commissioned. This system consisted of eight (8) 90M10C units and produced a nominal flow of 7.2 MGD and 4.2 MGD during winter operation.

Results

MEMCOR® CMF units were able to perform extremely well even at near freezing temperatures.

• By using the Programmable Logic Controllers (PLC), the system is highly automated. Operator interaction is only required for data retrieval and initiation of the cleaning cycle.
• Due to the low operator involvement and high recovery, operating costs are kept to a minimum.
• Recovery rates as high as 95% are achieved by the long backwash interval as well as the lack of filtrate water in the backwash step.
• Backwash water from the CMF units is returned to Lake Superior since there are no chemicals added to the water.

By choosing the MEMCOR® CMF system, the City of Marquette was able to meet all of its water needs.