Features

February 2014, Vol. 26, No.2

Taking the plunge 

Implementing a long-term, instrument-based program to assess compliance with water quality standards 

 

Feature 1 art Dominic L. DiSalvo, Alex J. Santos, and Mark L. Kosakowski
An efficient monitoring program can be a cost-effective method of providing a large quantity of detailed information that can be used to evaluate water quality and compliance with water quality standards (WQS), especially when the fallout from not meeting those standards can be in the hundreds of millions of dollars. Though establishing a long-term monitoring program may appear to be as easy as dropping a meter into water to collect data over time, there are various steps to developing and implementing a comprehensive, defensible program. It requires a tremendous amount of planning and preparation. Read full article (login required) 

 

Are your rates affordable? Your policy-makers want to know 

How utilities can create rate policies for low-income customers

feature 3 art Shawn Koorn

For the residents and businesses in affected cities, the capital and operating expenses associated with federal mandates are often reflected in water and wastewater bills that must grow faster than household incomes and the general rate of inflation. Very significant affordability challenges often are created, particularly for lower-income households.  

The effect of necessary capital improvements — either for renewal and replacement, or mandated improvements to meet regulatory requirements — will have a significant effect on future utility rates. However, capital improvements are not the single, driving cause of rapidly increasing utility rates. Other factors, such as declining per-capita consumption, lack of growth, and cost increases in operations and maintenance (such as labor, chemicals, and supplies), all play a part in setting utility rates. Developing utility rates that are affordable to all customers while still providing the level and quality of service that customers have come to expect is becoming more difficult to accomplish. Read full article (login required) 

 

Recharging coastal aquifers with reclaimed water 

 

The Hillsborough County Public Utilities Department recharges a stressed coastal saline aquifer with reclaimed water to help recover depleted water levels and guard against saltwater intrusion    

feature 5 art Harold E. Schmidt Jr., Michael Weatherby, Philip Waller, Bart Weiss, and James Duncan
Hillsborough County Public Utilities Department, a regional leader in Florida water reclamation and water resources protection, has a goal to achieve 100% reuse within its service areas. To meet this goal, the county is evaluating the direct recharge of reclaimed water from its south service area into a highly mineralized portion of the Upper Floridan Aquifer — more than 10,000 mg/L total dissolved solids (TDS). With seven water resource recovery facilities (WRRFs), the county at times has more reclaimed water supply than demand and was seeking a feasible beneficial reuse alternative to surface water disposal. Read full article (login required) 

 

Operations Forum Features

Finding the right system balance 

 North Carolina WRRF operators used on-line analyzers to help identify new approaches to process control and optimization 

feature 2 art Darrell DeWitt, David L. Wagoner, and Jacqueline Jarrell

Regulatory limits for water resource recovery facility (WRRF) effluents are becoming more stringent. As a result, WRRFs are being challenged as operating margins grow tighter. Operators are faced with achieving greater and/or more consistent performance to meet National Pollutant Discharge Elimination System (NPDES) discharge limits with existing and new facilities. 

Challenges at one WRRF — the Charlotte-Mecklenburg Utility Department’s (CMUD; Charlotte, N.C.) Mallard Creek Wastewater Treatment Plant — led to the use of on-line analyzers that helped develop and implement process control approaches that lead to more stable and efficient operations. Read full article (login required)                    

 

Flow woes 

 Effects and solutions for low velocities in force mains 

feature 4 copeland Bo Copeland and Sean O’Rourke

 Low velocity is a common problem in wastewater force mains (FMs). Although guidelines for wastewater pumping facilities typically recommend a design velocity of at least 0.61 m/s (2 ft/s) and a flushing velocity of at least 1.07 m/s (3.5 ft/s), there are some inconsistencies in these guidelines, and they are not applied in the same way by all engineers or on every project. 

The primary concerns associated with low velocities are solids deposition and accumulation of gas pockets, which can lead to pipe deterioration and reduced asset life. As utilities work to better understand their assets, extend asset life, replace aging infrastructure, and reduce costs, they often encounter the effects of low FM velocities, although they may not recognize it. Read full article (login required)