Palmdale Clearwells

Palmdale Water District

Palmdale, California

In this 6 million-gallon circular clearwell (194 ft in diameter; 27.5 ft deep; 30 MGD flow rate; average detention time of 0.2 days) the required T10 was 0.60.The initial proposed baffling design consisted of an inlet diametrically opposite to the outlet, and a series of seven cross baffles that forced the flow into a serpentine manner. The computed flow patterns showed separation zones behind each turn and a T10 of 0.52. This computed value compares very well to that for a similar arrangement.

Since T10 was below the target value, flow improvements had to be made. Flow Science helped in designing a new configuration that involved moving the inlet closer to the outlet and placing the baffles in a circular pattern that takes advantage of the column layout. This new arrangement resulted in a T10 value of 0.66.