Tuesday, September 10, 2024
11:00 AM - 11:30 AM
Location Name
Optimizing Filter Performance to Meet Growing Demands
Other/Special Topics

White House Utility District (WHUD) has been experiencing rapid population growth and increased water demands, much like most of middle Tennessee, pushing their only water treatment plant closer to its rated capacity. To maximize production and plant reliability, efforts to assess plant capacity, evaluate treatment performance, and identify process limitations led to a recommendation to optimize filtration. Filter Optimization consisted of high-rate flow stress testing several filters and initiating a Filter Surveillance Program. The initial effort consisted of high-rate flow stress testing on four of the plant’s 15 filters, one at a time, up to their maximum approved surface loading rate of 4.79 gpm/sf, while closely monitoring effluent turbidity, loss of head, and filter run times. The theoretical capacity of the filters at this maximum loading rate and a run time of 48 hours is 16 mgd, and the testing aimed to confirm that this flow capacity is achievable. The second component of the filter optimization, a filter surveillance program, consists of a hands-on evaluation process that helps facilities to identify and correct problems before they pose a risk of non-compliance, optimize backwash to effectively clean filter media while minimizing water waste, and improve filter runs. The first step in the filter surveillance process is evaluation of operating data, focusing on Unit Filter Run Volumes (UFRV) over time and the filter turbidity trends over the course of a filter run. This is followed by the physical condition assessment which involves draining and entering the filter box, observing the condition of all filter components, and sampling media for further evaluation. Physical observations, backwash waste turbidity, and retained turbidity on the filter media are all used to evaluate and improve the backwash process. Outside laboratory evaluation can show how filter media compares to design specifications and whether cleaning or replacement may be needed. The Filter Optimization effort undertaken by WHUD confirmed their existing filter rated capacity, and initiated their Filter Surveillance Program, resulting in improved plant operator knowledge and confidence and a shortened backwash sequence with longer filter run times. These achievements validate the merits of proactive filter maintenance and plant optimization while contributing to WHUD’s ability to provide cost-effective, high-quality water.