September 2010, Vol. 22, No.9

A new life for old tires

Constructed wetland with shredded-tire chips produces consistently high quality lagoon effluent

feature 1 William Li and Geoffrey Holmes

Fisherman Bay Sewer District (Lopez Island, Wash.) owns and operates a 129-m3/d (34,000-gal/d) aerated lagoon wastewater treatment plant. Nitrite and algae in the lagoon effluent presented a tremendous challenge for the plant operator to ensure consistent compliance with plant effluent fecal coliform, total residual chlorine, carbonaceous biochemical oxygen demand, and total suspended solids requirements.

To help stabilize treatment, the district investigated alternatives for removing algae from the lagoon effluent, ultimately finding an unconventional and cost-effective solution in a constructed wetland with tire-chip media. Read full article (login required)


The great economic disruption of 2009-2010

Implications for career planning in the water systems niche

feature 2 Donald Kerr

The status quo is that there is no status quo.

The water–wastewater industry is not recessionproof, but market research shows it managed to maintain modest growth during 2008 and 2009, and long-term trends favoring this niche as a place to achieve both career growth and a sense of service beyond self remain strong. Water and wastewater treatment is one of the most important market niches in the world, as it faces a world water crisis in which populations grow and water supplies shrink. Read full article (login required)


All for one, one for all

Virginia water and wastewater utilities unite to offer employees more educational opportunities at lower costs

feature 3 Keenan Howell

In a down economy with rising energy costs, it should come as no surprise to find a room full of wastewater engineers at a seminar on energy efficiency to learn money-saving measures they can implement in their operations.

However, the vehicle through which this training was made available was also designed, in part, to reduce costs associated with educating their work forces. The Virginia-based water reclamation facilities represented at the energy efficiency training are taking advantage of a new consortium spearheaded by the Prince William County Service Authority (Woodbridge, Va.) called the Northern Virginia Learning Center of Excellence for Water and Wastewater Utilities. Read full article (login required)


Operations Forum Features

Rebuilding through recruiting

How one utility bounced back after 10% of its work force retired

Feature 4 art Margie Anderson

Like many utilities across the nation, the Metropolitan Sewer District of Greater Cincinnati (MSD) is facing significant challenges resulting from a turbulent economy, baby boomer retirements, concerns of an aging infrastructure, and record high unemployment. Each of these factors contributes to uncertainty for the future.

To combat this challenge, MSD, undertook a multilevel succession plan focused on recruitment and public outreach. The plan has mitigated some of the risks of today’s workforce challenges. This robust plan includes showcasing the employment opportunities at various recruitment events and partnering with local high schools and colleges around the region. Read full article (login required)


A better mercury trap

Simple grab-sampling device for low-level mercury 

Feature 5 art Leo C. Fung

A plant mechanics creates a great mercury-sampling device. This new contraption will help to collect samples for low-level mercury analysis while avoiding contamination from the air. Read full article (login required)


Think you have a plugflow reactor? Think again!

Wastewater could be flowing through physical gaps, short-circuiting the biological treatment process

Feature 6 art Akram Botrous, Jeff Hauser, Steve Beck, Charles Slagter, and Bill Osmer

In suspended-growth biological treatment systems, plugflow reactors frequently are considered more efficient than completely mixed reactors because of their higher reaction rates. Design engineers often use multiple reactors in series to approximate plugflow conditions (“quasi-plugflow”). However, if hydraulic short-circuiting occurs, it can alter the biological system’s performance and capacity — and could lead to permit violations.

Unfortunately, such short-circuiting can go undetected for years, as a California treatment plant discovered after conducting a tracer study of its biological reactors. Read full article (login required)


©2010 Water Environment Federation. All rights reserved.