September 2011, Vol. 23, No.9

Nutrient compliance and a bigger carbon footprint?

Life-cycle assessments can help wastewater treatment plants strike a balance among competing environmental impacts

carbon footprint art Andrew Shaw, Chris deBarbadillo, Steve Tarallo, and Anjana Kadava

Several North American regions are facing stringent total nutrient limits, ranging from 0.05 mg/L total phosphorus (TP) in Colorado to 0.01 mg/L TP effluent concentrations in Lake Simcoe, Ontario. The only possible response is to build process facilities designed to achieve these lower limits, but this action increases chemical and energy consumption for only an incremental decrease in effluent loads. Cost implications aside, such construction also presents significant environmental impacts.

Lowering nutrient loads helps to prevent eutrophication, which has its own serious, negative impact, but in doing this, wastewater treatment plants (WWTPs) may worsen other environmental impacts, including carbon footprints. WWTPs can use life-cycle assessment (LCA), a technique that measures the direct and indirect environmental impacts of a specific process, to compare and balance these effects. Read full article (login required)


Will U.S. POTWs need a carbon diet?

While most U.S. wastewater treatment facilities are currently exempt from greenhouse gas reporting rules, that could change. In the meantime, other countries are imposing emissions restrictions

carbon diet art Laurie Ford, Bob Dominak, Bill Barber, Tony Koodie, Patricia Scanlan, and Ajay Kasarabada

Whether they currently report greenhouse gas (GHG) emissions or not, all publicly owned treatment works (POTWs) should be aware of two recent regulations: the 2009 Mandatory GHG Reporting Rule and the 2010 GHG Tailoring Rule. The two rules have different requirements and implications that are important for wastewater utilities to understand. Read full article (login required)


How to rate a watershed’s sustainability

The authors propose a method that combines the work of others to determine the impacts of humans — as well as municipal and industrial facilities — on watersheds

LCA art Ethan T. Smith and Harry X. Zhang

Human activity, at a minimum, should only use nature’s resources at a rate at which they can be safely replenished naturally so that future generations can meet their own needs. This is sustainability.

To determine whether a current level of activity is sustainable for water resources in a particular watershed, stakeholders need to rate such elements as the human use of a watershed’s physical characteristics, municipal water and wastewater system components, and major industries with water and wastewater facilities. These elements seem to have the greatest potential for affecting a watershed’s long-term viability. Read full article (login required)


Operations Forum Features

Exam in progress

A guide to preparing for certification

certification art Suzanne De la Cruz

Environmental certification and licensing programs vary greatly. Some are voluntary; others are mandatory to work in certain job positions. For example, wastewater treatment plant operator certification is mandatory in every U.S. state, but laboratory analyst certifications often are voluntary.

Both voluntary and mandatory certifications benefit the profession by documenting an individual’s professional competence and showing that individuals have met industry certification standards. Even though significant differences exist among certification programs, there are key resources and strategies that can help all applicants in the quest to become certified. Read full article (login required)


A sustainable training solution

Union Sanitary District’s competency-based workforce development program looks to the future

in-house training art Michelle Powell

The Union Sanitary District (USD; Union City, Calif.) once approached training the same way many utilities do: Experienced employees who showed a talent for providing instruction were paired with less-experienced workers to pass on their knowledge. The problem with using this type of informal system to meet training needs was that the effectiveness of the instruction couldn’t be measured reliably. In addition to providing the training required by the U.S. Occupational Safety and Health Administration and other federal or state regulations for employee safety and certification purposes, USD is committed to providing training that supports the district’s strategic objectives.

USD saw the need to develop a professional, standardized method to deliver training and capture the extensive institutional knowledge that its workforce had in their heads. Read full article (login required)


Using social media for effective communication and outreach

social outreach art Maureen Barry and Daniel Jaimes

Social media is bringing innovation and change to public communications and outreach in fascinating new ways. In an age of 140-character tweets, blogs, Facebook “likes,” and YouTube videos, government agencies and their consultants are finding new ways to educate, engage, and communicate with stakeholders, reporters, residents, and industry professionals. The San Francisco Public Utilities Commission (SFPUC) is using affordable and often free social media networks to develop strong community relations and build public awareness for its $4.6 billion Water System Improvement Program (WSIP) — or in Twitter terms: @WSIPInTheNews. Read full article (login required)


A new generation of optical dissolved oxygen sensors

DO sensor art Robert Hengel and Klaus Reithmayer

Compared with conventional electrochemical oxygen sensors for dissolved oxygen measurements in wastewater applications, optical dissolved oxygen (DO) sensors offer numerous benefits for the measurement of oxygen concentration, including eliminating the need for calibration. However, in practical applications, these first generation optical sensors display certain shortcomings that result in a lack of accuracy and stability. The past year has seen the emergence of new optical DO sensors that have been designed to achieve the best possible accuracy from the very beginning and maintain this precision throughout the entire product life span. Read full article (login required)