WE&T Magazine

   Water Environment & Technology (WE&T) is the premier magazine for the water quality field. WE&T provides information on what professionals demand: cutting-edge technologies, innovative solutions, operations and maintenance, regulatory and legislative impacts, and professional development.

 


January 2015, Vol. 27, No.1

 This annual section examines the hot topics facing the water sector today. This year the focus turns toward the gaining advantages with real-time data and controls, debating climate change and resiliency, and drawing a roadmap toward resource recovery. 

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Featured Articles

Go beyond the conventional

Feature 1 art The Bowery Bay Waste Water Treatment Plant (New York) recently upgraded to a biological nutrient removal (BNR) system to meet increasingly stricter limits on effluent total nitrogen (TN). Optimizing the BNR process involved obtaining control over primary effluent (PE) flow distribution to each of the four passes of the step-feed secondary treatment system. Optimizing flow distribution to each pass allowed for more efficient nitrification and denitrification by balancing the conflicting drivers of maximizing solids retention time (SRT) for nitrification while still providing adequate PE carbon for denitrification.

 

Get real

Feature 2 art The City of Ottawa (Ontario, Canada) implemented real-time control (RTC) to minimize combined sewer overflows (CSOs) to the Ottawa River. The RTC system consists of flow control structures that are operated automatically and dynamically in response to real-time sewer conditions. This system has helped the city cost-effectively meet CSO objectives by maximizing use of existing infrastructure.

 

News

Sharing the wealth


A water recycling facility in the California Bay Area gives away water to help mitigate the drought   

Desperate times call for desperate measures. But, in the case of the Dublin San Ramon Services District in Dublin, Calif., desperate times — specifically a dire, regional drought — also led to ingenuity and the creation in June of the first recycled water giveaway program of its kind in the U.S.   
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Coming in the next issue:

Adapt and prosper


The water sector excels at creating standard operating procedures to accomplish Herculean tasks from treating 100 million gallons of wastewater per day, to removing pollutants from a combination of wastewater and stormwater, to producing effluent cleaner than its receiving stream. Reaching these clear and straightforward procedures, however, requires asking some hard questions about the way things have been operating until now. This issue of WE&T presents examples of how some different thinking and approaches can lead to gains in program, project, and unit operation efficiency.
 

“Are incentives converting skeptics or just preaching to the choir?” considers whether incentives spur stormwater projects. Financial incentives include grants, direct cost sharing, user fees, and coupons. Nonfinancial incentives encompass awards and recognition, education and outreach, and giveaways. As more communities dedicate public funds to stormwater management incentives, they need best practices to ensure the money, time, and effort achieve results. 

On a more concrete note, “A clear winner” describes how a utility combined thickening and grit removal in the world’s first large-scale primary dissolved air floatation (DAF) clarifier. The Pima County Regional Wastewater Reclamation Department in Tucson, Ariz., started this process at its new 105-million L/d (32-mgd) Agua Nueva Water Reclamation Facility about a year ago. The new DAF eliminated the need for separate solids thickening and grit removal while improving oil and grease removal. 

After a year of operation, the primary DAF clarifiers have shown performance similar to that of conventional primary clarification while combining waste activated sludge and primary sludge thickening and grit removal in a single unit process. The DAFs have removed between 50% and 75% of suspended material and between 30% and 50% of influent chemical oxygen demand while reliably producing a thickened sludge.   

Changing conditions also spur adaption. For example, the Silicon Valley Advanced Water Purification Center in San Jose, Calif., combines microfiltration, reverse osmosis, and ultraviolet light to produce up to 30.3 ML/d (8 mgd) of purified water. The Santa Clara Valley Water District, which manages the purification center as part of an integrated water resources system that serves 1.8 million residents and 200,000 commuters, faced challenges with growing water demand, uncertainty in imported water supplies, recurring drought, regulatory restrictions, and climate change. The purification center will help the district provide at least 10% of demand with recycled water by 2025 by treating secondary effluent to drinking water standards.