June 2011, Vol. 23, No.6

Four MBRs are better than one 

Paulding County, Ga., used a decentralized configuration to effectively reclaim treated wastewater and combat growing pains

Jones art.jpg Michael L. Jones and Kimberly N. Mathis

Eight years ago, Paulding County, Ga., home to 145,000 people and covering approximately 830 km2 (319 mi2), consistently ranked between the 12th and 15th fastest-growing counties in the United States. The county’s Pumpkinvine Creek Wastewater Treatment Plant, which had been using a sequencing batch reactor (SBR) and sand filter system, was operating close to design capacity. With tighter effluent limits on the way, a halt on surface water discharge permits, and an increase in required capacity, the county had to look at alternative uses for its treated wastewater. Reuse became the only viable option.  Read full article (login required) 


A storm of change

How a hurricane helped a utility meet its needs for the future 

haag Tim Haag

During the early morning hours of Sept. 16, 2004, Hurricane Ivan roared ashore. The Category 3 storm delivered 160-km/h (100-mi/h) winds and a 5-m (15-ft) storm surge to Pensacola, Fla., battering and submerging the 76,000-m3/d (20-mgd) Main Street Wastewater Treatment Plant (MSWWTP).

After the storm, the plant was under water and had no power. MSWWTP was out of service for 3 days. Following Ivan’s strike, some areas in downtown Pensacola were flooded with a combination of stormwater, storm surge, and untreated wastewater.

The consequences of this storm reinforced what the Emerald Coast Utilities Authority (ECUA; Pensacola), which oversees Pensacola’s water and wastewater systems, already knew: The wastewater treatment plant had to be replaced. Read full article (login required) 


Engaging staff for IT culture change

More than 100 employees devoted more than 140 planning hours, 4 weeks of formal training, and more than 2 weeks of hands-on learning to bring an updated, cost-effective $1.4 million CIS-CMMS system on-line in Fulton County, Ga.

bash Scott Bash

Whenever managers bring up the subject of new technology or business processes, staff members often groan. They know that implementing these systems will require training time that may take away from their primary tasks, and they often are skeptical about how such moves may affect their positions and whether the new way of doing business will be any better.

To head off some of these acceptance issues, Fulton County, Ga., teamed with a consulting firm to fully engage more than 90 staff members in teams across five departments to assess their current information technology (IT) systems and develop a plan for one that would optimize the county’s water and sewer service operations. Read full article (login required)


Operations Forum Features

Maximize filtration effectiveness 

Solids loading controls tertiary filter run time 

Peng_Art Weihua (Peter) Peng, James Pawlowski, and Kevin Corsaro

Tertiary filters are a critical wastewater treatment process; they help capture solids escaping secondary clarifiers and maintain a great final effluent quality. Although many filter technologies can be used, slow sand filtration is still widely applied because of its reliable performance and low maintenance costs.

Researchers recently conducted a series of full-scale stress tests on a group of sand filters to determine which factors most affected filter capacity. They found that solids loading is more important than hydraulic loading. Read full article (login required)


Solids yield surprise

Research on trickling filter/activated sludge systems produces unexpected results

Gharagozian_Art Andre Gharagozian, Steven Swanback, B. Narayanan, and Rick Chan

Although more and more trickling filter plants are upgrading to trickling filter/activated sludge processes to increase capacity or improve effluent quality, little is known about these processes’ solids yield (i.e., pounds of total suspended solids [TSS] produced per pounds of biochemical oxygen demand [BOD] removed). Solids yield at wastewater treatment plants is a crucial design parameter for sizing aeration tanks and solids-handling facilities. It also greatly affects operating costs. Read full article (login required)

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