Look Before You Dig
Abandoned utilities may be suitable for reuse in new collection system projects
John J. Scheri, Joseph P. Skelly, and Stephen Gitungo
When the Kearny (N.J.) Municipal Utilities Authority (MUA) needed to construct a 2.4-km long (1.5-mi-long) force main and two pump stations in an industrial area that already had two interstate highways, multiple underground utilities, and tidal wetlands, the project team needed to think creatively. A little research revealed an abandoned gas main that could serve as a host pipe for the force main, which enabled the project to be constructed faster, safer, and less expensively. It also minimized installation effects on traffic and the environment. Read full article (login required)
Numeric Nutrient Criteria on the Horizon
Can nutrient removal surpass the limits of technology?
Scott Levesque, James Barnard, Chris deBarbadillo, and Rafael Frias
Numeric nutrient criteria have the potential to require some wastewater treatment plants to produce effluent with nutrient concentrations below the commonly accepted limits
of technology (LOT): 3 mg/L total nitrogen and 0.1 mg/L total phosphorus. In wastewater treatment, the term “LOT” should not be taken literally; it carries an unstated degree of reasonableness and practicality. However, uncertainty with respect to pending numeric nutrient criteria is causing the engineering and regulated communities to consider how, reasonableness and practicality aside, ultralow nutrient concentrations could be achieved. Read full article (login required)
How Low Must You Go?
Continuous-backwash filters can meet exceptionally low effluent nutrient limits
Paul M. Sutton, Oliver J. Schraa, and Remembrance L. Newcombe
For decades, continuous-backwash filters have been used to treat suspended solids, turbidity, and nitrate in wastewater. More recently, the technology has been applied for the removal of phosphorus and other contaminants (such as ammonia, perchlorate, and selenium). The use of reactive filter media versus inert media in certain of these applications improves treatment efficiency. Read full article (login required)
Operations Forum Features
Factoring Condition Assessment and Asset Management Into Capital Planning
With limited funds, it is more important than ever to invest capital for the maximum benefit. Condition assessment is the process of determining the overall health of an asset — a process that sounds simple but in reality is not rigorously implemented or commonplace in the industry.
Indeed, new condition assessment criteria and approaches are on the leading edge of development in both the equipment maintenance and reliability communities. Read full article (login required)
The Right Tool, The Right Way
The case for renting equipment
Most of us buy equipment when we need it. However, stopping to consider renting may bring some benefits and save some money in the long run. This article discussed what to consider when making the decision to rent or buy. Read full article (login required)