FEATURES

Membranes for Water Reclamation
An overview of this up-and-coming water-treatment approach
Scott Freeman, Gordon F. Leitner, James Crook, and William Vernon

In 1991, C.A. Blanck, director of water control at the American Water Works Co. Inc. (Voorhees, N.J.), wrote that "although membrane technology is not new, its application for use in the water utility field has been limited by its perception as being almost Buck Rogerish." That perception changed during the last decade. Today, more than 20 membrane-based water reclamation facilities are operating in the United States, and more now exist worldwide in such places as Australia, Singapore, and the Middle East.

Fishing for Fingerprints in BNR Systems
In contrast to culture-based techniques, molecular-biology-based techniques use a unique fingerprinting technique to more accurately identify and enumerate microorganisms, mediating biological nutrient removal
Daniel B. Oerther, Sam Jeyenayagam, and Joe Husband

Since the beginning of biological wastewater treatment, the primary goals have been removing soluble organics and suspended solids while minimizing costs. Technologies developed almost a century ago, namely, fixed-film and suspended-growth treatment systems, are still used to treat approximately 30 billion gal (114 million m³) of wastewater daily in the United States. The success of these treatment technologies hinges on maintaining a diverse community of microorganisms that can remove myriad anthropogenic wastes.

Better Feeding, Better Biosolids
A Colorado wastewater treatment plant replaces a decades-old coagulant-feeding system with a more flexible and reliable one, consistently ensuring quality biosolids
Steve Walker

When a facility spends close to $1 million annually on cationic dry polymers for sludge dewatering, these coagulants had better work as efficiently as possible. The polymer used also should be the most effective technology offers. These were two overriding concerns of the Metro Wastewater Reclamation District (Denver, Colo.) several years ago when it decided to replace its old polymer batch-feed system.

NEWS

Need Capital Funding? SRF Money Available
Looking for financing for a sewer separation, plant upgrade, or water reuse project? Over the course of the program, the Clean Water State Revolving Fund (SRF) has provided $34.3 billion to clean water projects. During fiscal year 2001, the SRP program awarded over $3.8 billon in low-cost, low-interest loans, and this year an more than $3.5 billion will be available, according to U.S. Environmental Protection Agency statistics from the Clean Water State Revolving Fund Branch.

Water Infrastructure Spending Gap Finally Getting Attention It Deserves?
Over the past few months, the federal government's attention has been focused on the nation's economy and the security of its infrastructure. But does the current focus on security issues help or hurt the repair and upgrade needs of water and wastewater infrastructure?

U.S. Congress To Fund Security Research
Initial reactions in the water and wastewater sectors to the Sept. 11 attacks have largely centered around simple, physical threats to infrastructure, but concern is growing that whatever changes are implemented need to be geared for the long-term, moving beyond erecting more barriers, posting more guards, and installing motion sensors and closed-circuit video systems. As a result, research agendas at the U.S. Environmental Protection Agency (EPA), trade organizations, and companies are changing.

OPERATIONS FORUM
A special section for operators

Maximum Security
Protect your infrastructure with a structured approach for security assessment
Christine A. Cooper and David B. Dobbins

Throughout the United States, utility management and staff alike are considering how best to protect their systems in light of the heightened state of alert since Sept. 11. In an industry where protecting the public health is the main goal, the need to act quickly to reduce risk is a necessary and common response. Unfortunately, the risk from terrorism is new to the industry, and utility personnel may not feel equal to the task. The need to "do something" may result in reactive spending that appeases public concerns but does little to reduce the greatest threats to the system.

Brainstorming sessions currently occurring within utilities are likely to raise many questions, from "How do I protect the chemical tanks?" to "What could a terrorist do to cause the most damage to my facility?" A structured approach for security assessments can help utilities better understand the process and the next steps toward securing their assets.

Let There Be Light!
Compare ultraviolet disinfection system design at two Georgia facilities
Gregory V. Goodman and Jeffrey A. Mills

The R.M. Clayton Water Reclamation Center (Clayton WRC; Atlanta, Ga.) and the R.L. Sutton Water Reclamation Facility (Sutton WRF) are separated only by the Chattahoochee River, but their ultraviolet (UV) disinfection systems are worlds apart. Major expansion projects at both facilities provided each the opportunity to upgrade its disinfection system. The Clayton WRC opted to use the same open-channel, gravity-flow, medium-pressure, high-intensity system used at two other Atlanta facilities, creating a "standard" system for the city of Atlanta. Meanwhile the Sutton WRF, in neighboring Cobb County, decided on a closed-vessel, medium-pressure, high-intensity system (operational by the end of 2003) that requires fewer lamps, which are easy to replace. Despite their significant design differences, both are equally effective and, when both are operational, will be among the largest UV disinfection systems of their type in the United States.

Step Up To Savings
A North Carolina facility uses step-feed operations to conserve energy
W. James Gellner, Stanley B. Webb, J. Frank Crump, L. Kevin Mosteller

The Archie Elledge Wastewater Treatment Plant (Winston-Salem, N.C.) is owned and operated by the Winston-Salem/Forsyth County Utilities Commission and is one of two major municipal treatment plants that serves the Winston-Salem area. The 30-mgd (114 000-m³d) conventional activated sludge treatment plant was experiencing periodic zoogleal bulking episodes caused by high soluble biochemical oxygen demand loading and low dissolved oxygen (DO) conditions, which required over-aerating the downstream cells of the aeration basins. Hoping to reduce energy costs while still maintaining acceptable process performance in the activated sludge basins, plant staff and engineering consultants implemented a step-feed design to the aeration basins to spread organic load along the entire length of the aeration basins and achieve denitrification using anoxic cells at the step-feed locations.