March 2008, Vol. 20, No.3
Low-flow toilets. Carbon offsets. Rain gardens. These are topics familiar to WE&T readers because water quality professionals increasingly are embracing “green” technologies. In this issue we look at some environmentally friendly options for wastewater treatment plants, as well as the associated costs.
In “Green Incinerators” James Welp and his co-authors come to some surprising conclusions when they compare greenhouse gas emissions for different solids processing scenarios. In “One Mile Under,” the focus shifts from keeping emissions out of the air to injecting biosolids deep into the ground. If successful, this ambitious deep-well injection demonstration project in Los Angeles could be a model for wastewater agencies seeking an alternative to land application.
Utilities may be compelled to “go green” because it’s politically correct, but does it always make good financial sense? In “Green at What Cost” Mary Bufe examines the economic offsets of green technology, as well as some cost-effective green solutions that utilities have implemented.
Melissa Jackson, editor
Operations Forum Editor's Note
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it’s the only thing that ever has.”
— Margaret Mead, distinguished anthropologist, intellectual, and scientist
In this season of primary elections and caucuses, this quote might seem to be about politics, but, to me, it’s about cooperation and teamwork. Operating, maintaining, and improving complicated systems require an incredible amount of knowledge and ingenuity. It is rare to find a lone person who is an expert on each process in a treatment plant and on how each process interacts with the others. And even the best of the best can benefit from a new perspective. Building groups where some members’ strengths compensate for others’ weaknesses makes for an effective team and effective projects.
For example, squeezing more than 40% additional capacity out of a treatment plant using the same footprint takes the skills and talents of several people. Check out “No Space? No Problem!” (click here) to find out how the Marco Island Wastewater Treatment Plant met this goal while also increasing its effluent quality and increasing its reuse options.
But sometimes even with a good team in place, the first shot at a project doesn’t quite make the grade. The solution: Assemble a new team with different skills and knowledge, and begin troubleshooting and retesting.
When phosphorus levels began to creep up immediately following the startup of its new tertiary ballasted flocculation settling system, the Metropolitan Syracuse (N.Y.) Wastewater Treatment Plant assembled an optimization team of process experts, operators, and laboratory analysts. “Tertiary Troubleshooting” (click here) details how the team examined each step of the new process to determine why nutrient levels had increased and to ensure the best possible treatment into the future.
Likewise, when a newly installed ultraviolet disinfection system failed to meet discharge requirements at the City of Longmont (Colo.) Wastewater Treatment Plant, staff mounted an intense investigation to figure out what went wrong. They evaluated transmittance data, the effectiveness of radiation doses in killing coliform bacteria, as well as how the plant’s total suspended solids were affecting the system. The article, “UV Disinfection for a Real-World Effluent,” (click here) includes the step-by-step procedure of how the city worked out the problem and successfully redesigned its system.
If anything worth doing is worth doing well, then anything worth doing is worth taking the time to assemble a well-rounded team.
Steve Spicer, editor