DWG ASSOCIATES, Inc.
Design Engineering for Wastewater and Water
Systems
News & Recent Activity
-- Last updated: Feb., 2012
UNOX & Cryo Plant Training for Hopewell, VA
As your plant evolves, operator training
ensures efficient plant operation . . .
Years of operating experience can sometimes inhibit efficient plant operation. The Hopewell (VA) Regional Wastewater Treatment Facility (HRWTF) realized this after a recent plant modification. After completion of the modification (which actually downsized the cryogenic plant main air compressor), the operations staff was uncomfortable because certain operating parameters (like D.O. concentrations) couldn't be maintained at the historically high magnitudes the staff was used to. A DWG ASSOCIATES' customized operator training program, which included hands-on cryo plant training, reoriented operator habits such that the HRWTF is now operating efficiently, wasting less oxygen and consuming less power all while meeting effluent permit requirements.
Louisville, KY upgrade (Morris Forman Plant)
Upgrading a high-purity oxygen (UNOX)
system without the system supplier . . .
Working with CH2M Hill, DWG ASSOCIATES designed, then monitored equipment purchasing and construction of a complete replacement of old, obsolete UNOX System mass transfer equipment and instrumentation. Together, CH2M Hill and DWG ASSOCIATES acted as the oxygen system supplier. Removing the system supplier from the construction phase of the project eliminated an entire additional vendor layer, saving the Metropolitan Sewer District considerable money without sacrificing equipment or process guarantees. In addition to the capital cost savings, the new high efficiency aeration equipment is also saving significant operating monies compared to the old, inefficient equipment. The upgrade is complete and currently operating.
East Bay MUD (Oakland, CA) energy audit
Want to save power or shed load during peak
utility hours? - conduct an energy audit . . .
Working with HDR Engineering, DWG ASSOCIATES conducted a comprehensive energy audit of East Bay's Main Wastewater Treatment Plant (MWWTP) UNOX System. Connected load and current operating philosophy were determined through detailed discussions with the operations staff. Using the prevailing power cost schedule for the MWWTP, specific power saving and load shedding modes of operation were defined. Capital costs were established and a net present value analysis was used to identify the most attractive energy saving and/or load shedding modes of operation. Approximately $500,000 in potential annual electric energy saving for this plant have been identified to date. This project is ongoing.
Detroit's unique upgrade specifications
This specification "caps" (and guarantees) the owner's
power costs to those associated with the
most energy efficient equipment available in the
current market . . .
DWG ASSOCIATES, the City of Detroit, and Metcalf & Eddy|AECOM presented a paper at WEFTEC 2007 on the specifications that were developed for the latest secondary system upgrade for Detroit's 930 mgd wastewater treatment plant. The presentation, titled "A Simple Specification that Guarantees State-of-the-Art Operating Efficiencies," discusses how the Detroit specification secured an aeration system with state-of-the-art energy efficiencies. The upgraded aeration system consumes 40% less power than the original oxygen dissolution system. The unique aspect of the specification is that Detroit would only have paid for the energy associated with these state-of-the-art aerators even if the actual, purchased aeration equipment was not state-of-the-art. So for Detroit, energy outlays for the next 20 years were limited, or "capped," regardless of the energy efficiency of the actual equipment installed. That's a good deal, no matter how you look at it!
Read/download a copy of
the paper . . .
HERE
[You'll need Adobe's Acrobat reader,
available below]
Orange County (CA) oxygen supply system upgrade
To get ready for the next 20 years, do you refurbish an
existing oxygen generator or replace it . . .
The Orange County Sanitation District's (OCSD) Treatment Plant #2 high-purity oxygen secondary system was originally designed with two 72 tons/day cryogenic oxygen generators. Due to in-plant modifications and changing influent characteristics over the years, the cryogenic oxygen generators became far too large for the secondary system's oxygen demand. With considerable operating life remaining however, the question for OCSD was - refurbish or replace the generators? Detailed oxygen supply alternative economic analysis prepared by DWG ASSOCIATES indicated significant operating cost savings would be possible by adopting a new oxygen supply technique. After specification preparation and bidding, a new, long term liquid oxygen (LOX) supply system is being implemented. The new supply system required approximately $300,000 in capital investment but will save in excess of $550,000/year in operating costs compared to the continued operation of the cryogenic generator.
Yuba City, California aerator upgrade
In-the-field aerator test program results in
33% reduction in high-purity oxygen system
aeration costs . . .
In conjunction with the Yuba City operating staff, DWG ASSOCIATES oversaw an aeration equipment manufacturer's ASCE standardized surface aerator test program that used one of Yuba City's actual HPO tanks. That is to say, the testing was done in-the-field using the exact tanks where the aeration equipment would be installed. After testing, Yuba City personnel manufactured and installed one complete aeration train with the high efficiency surface aerator turbines that were tested. The resultant increase in mass transfer capabilities allows the Yuba City plant to operate with about 35% less dissolution power than the old, original aerators were consuming.
Read/download a copy of
the paper . . .
HERE
[You'll need Adobe's Acrobat reader,
available below]
Recent or Additional Publications/Papers
DWG ASSOCIATES periodically authors
papers detailing
our current work activities. Below is a representative
selection of some of our recent publications. If you don't
see it below, contact us.
"Computer Simulation: The Plant Operator's Optimizing, Troubleshooting, and Training Tool," was coauthored with the Sacramento Regional County Sanitation District and Carollo Engineers. The paper describes how sophisticated plant simulation software can be used by wastewater treatment plant personnel to improve the operation of their facility.
Read/download a copy of the paper . . . HERE
"Beat Your Service Providers like a Drum and Save Big Bucks in the Process (A Case Study of One Facility that Saved more than $200,000 per year)," was coauthored with the Orange County (CA) Sanitation District's Mr. Mark Esquer. The paper's title says it all; watch that vendor.
Read/download a copy of the paper . . . HERE
"Clean Water Testing of Innovative Surface Aerators Promises Significant Savings for Chattanooga's Moccasin Bend WWTP," was coauthored with Consolidated Technologies, Inc. The paper describes the ASCE standardized tap water testing program conducted to confirm the power consumption guarantees that the equipment supplier committed to at bid time.
Read/download a copy of the paper . . . HERE
To get the Adobe Acrobat reader click on the
graphic . . .
