Cogen Plant Sets New Standards

The M/E Roundtable for September focused on cogeneration, and one of the most innovative projects of the year involves the construction of a combined cogeneration power plant and wastewater treatment plant in Klamath Falls, Ore.

By Mike Kuenzi, P.E., Director of Public Works for the city of Klamath Falls September 19, 2001

The City of Klamath Falls will soon have one of the most innovative “green” industrial facilities in North America, thanks to a creative new approach in wastewater and cogen technology. This south-central Oregon community is busy completing a new 500-mw cogeneration plant, upgrading the 4.3 mgd (average dry weather flow) Spring Street Wastewater Treatment Plant (WWTP) and extending a geothermal water loop to heat the WWTP control building, melt sidewalk snow and provide back-up heat for the WWTP digester.

This is the first new major merchant plant built on the West Coast in many years and will service energy-starved California and the Northwest-enough electricity for the equivalent of 400,000 homes.

The other generated product of the plant is-steam. The cogen plant will generate and sell steam to local businesses. This will help them to remain competitive in the national and international marketplace while reducing their dependence on their own gas, oil or wood waste boilers. And for local gardeners or farmers, the city provides free compost from the WWTP’s mixed sludge.

The Team

Early on, city officials chose two international companies that are experts in their fields to manage the project: PacifiCorp Power Marketing, Inc. (“PPM”) for the $300 million+ cogen plant and Brown & Caldwell for the WWTP reliability upgrades. PPM formed a project-specific limited liability company-Pacific Klamath Energy LLC, which in turn is managing the main design/supply/construct contract with the joint venture of Black & Veatch and Jones Construction (BVJ). For the WWTP construction project, the City hired a company with extensive construction experience in the Northwest-IMCO General Construction.

Groundbreaking for the cogen plant occurred in June 1999 and the upgrade to the WWTP began in May 2000, and both were ready to go online this July. The City owns the plant and it is operated and maintained by Pacific Klamath Energy LLC. But how did this unusual project come together?

History: Vision, Visionary Collaborate with Engineering

The City was approached by Pacific Power in the late 1970s to explore the possibility of a hydro project. But that didn’t work out-especially not after the nearby Klamath River was declared a Wild and Scenic River by the then Secretary of the Interior, Bruce Babbitt. And after environmental regulations in the 1980s helped reshuffle the local economic deck, this once-prosperous logging town found itself mired in no-growth and double-digit unemployment. As recounted by current City Manager, Jeff Ball, “The City needed to do something to help pull the community out of its problem, so Klamath Falls initiated an ‘Operation Bootstrap.'”

By the mid 1990s the idea for a cogen plant began to develop, and the state set conditions for one 500mw plant to be built in Oregon. This was basically a beauty contest among three contestants, and the major issue was which project had the best environmental mitigation package.

In the end, the Klamath Falls proposal won the endorsement of Oregon’s Energy Facility Siting Council (EFSC). The certificate to build was received in late 1997 with final amendments accepted in 1998. Perhaps just as importantly, the city also gained the support of several key environmental groups such as Northwest Environmental Advocates and Renewables Northwest.

“The driving force from the City side was (retired City Manager) Jim Keller,” said Ball. “Jim began working on this project back in 1985 and saw it through until 2000. He worked very hard at building alliances and cooperative relationships. He did an outstanding job.”

Keller himself gives credit to others, but his strategy was clear: If possible, get everyone on board in the beginning. Take the time to build consensus. “We understood that we would have to design a project that would gain the approval of local and regional environmental groups,” he said, “so we sat down with them early on and sought their input. Many of the environmentalists were very good to work with.”

So good, in fact, that a highly cooperative tone was set in the early days. “During one of the hearings,” recalled Keller, “one of the leaders of one of the larger environmental groups came over and shook my hand and together we committed to working together on this project.”

So Keller’s philosophy was simple: Talk first, design second. Negotiate and resolve the issues before the project is set. Then design the plant. “There needs to be economic and environmental checks and balances,” he said, “Both sides have faults.. everyone is a little bit wrong. It is important in avoiding the extremes to work together. In this project, we decided that we did not want to spend our money in court, but instead spend it on working with industry and environmentalists to find solutions.”

Solutions, indeed. With this approach, Keller helped lay the foundation for a project that could succeed in the long-term-partly because he had done his homework, partly because he refused to cut corners. The cogen plant at Klamath Falls, as he envisioned it, would “raise the bar technologically and environmentally.”

Not to mention financially. The plant is being financed by revenues from a City-sponsored $300 million bond. These bonds were purchased primarily by institutional investors. This allowed the City to use private money to build a large public project that will provide opportunities for many private businesses, while generating energy for local and West Coast businesses.

Technically Speaking

The cogen plant is incorporating state-of-the-art equipment throughout the facility. Bill Byrnes, site construction manager for PPM’s subsidiary Pacific Klamath Energy (representing the owner) and veteran of many power and industrial projects, explained that construction challenges in projects this size can begin early. This project was no exception. “The site is zoned for industrial use,” he said, “and formerly this location was a log yard for the Weyerhaeuser mill, which is now Collins Products. When the excavator, LTM Inc of Medford, began digging, he had to cut as far down as 20 to 30 feet to hit a workable base. He ended up removing approximately 200,000 cubic yards that was filled with bark and wood debris.”

The new advanced combined-cycle cogeneration plant will use two Siemens Westinghouse 501FD gas turbines that will each produce 165 mW of power. The hot exhaust gases go from the turbines to two Toshiba heat recovery steam generators (HRSG) which power the ALSTOM (formerly ABB) steam turbine. This combined cycle will produce net power at a very low heat rate – less than 7000 Btu/kWh, HHV basis. Some steam will also be sold and piped to Collins Products and other industrial users in the industrial park. For this project, the boilers were so large they had to be assembled on-site. Each of the three turbines required 1,000 cubic yards of concrete for the base since the site is located in a seismic zone. Over 18,000 total cubic yards of concrete were used.

Next to the cogen plant is the large electrical switchyard, which will connect to an existing 500kV line less than a mile away. The evaporative cooling tower system consists of eight cells and will evaporate 65 percent of the effluent. This leads to the next important component of this successful project: the wastewater treatment plant (WWTP).

While smaller in scope, the WWTP Reliability Upgrade Project involved critical challenges and innovative approaches and technologies. One of the more unusual involves extending the city’s geothermal heat loop. The city uses the 180 degree natural geothermal water to heat many of its buildings, sidewalks and even some of the downtown businesses and in this project, the city wanted to extend the geothermal loop to provide space heating to the WWTP’s control building as well as provide a reliable backup heat source to the digesters. The plan for the contractor, IMCO General Construction, to route the geothermal pipe even included a number of plant sidewalks to melt the snow. In addition, all geothermal work and the construction upgrade to the WWTP had to be accomplished while the treatment plant was operating 100 percent of the time.

Engineers from both the WWTP and the cogen plant worked closely together to produce a WWTP effluent that met the cooling water quality needs. The effluent was “super-chlorinated” to kill the algae and the process was modified to remove phosphorus. Effluent turbidity monitoring was added to provide immediate indication if the effluent quality deteriorates.

The WWTP will provide the cogen with an estimated 2.8 to 4.2 million gallons a day in cooling water with over 65 percent of the water being evaporated in the cooling towers. The remainder of the water, called the blow-down, is returned to the WWTP where it is dechlorinated and reduced in temperature prior to its discharge into the Klamath River.

The recycling of the WWTP effluent through the cogen does two things–one, it alleviates the dependency of the cogen plant to use freshwater in its cooling process. And secondly, the evaporation process reduces the amount of discharge going into the river by approximately 2.3 million gallons per day.

And that’s not all: Added to this, is the fact that reuse of the effluent is now essentially and ultimately a revenue generator because profits from the power sales will eventually come back to the City. In addition, profit from the steam sales will go to supporting the on-going maintenance, operation and expansion of the City’s geothermal system which will include over 100 offices and buildings.

Scheduling has been a critical element, as well, since the cogen plant depends on the WWTP. Because the cogen plant is dependent on the cooling water from the treatment plant, we had to design and build a back-up system for the plant’s processes. This means redundancy in all the major components-more pumps, storage, chlorination capabilities and greater operational flexibility. And according to Brown and Caldwell’s Principal Engineer, Jack Detweiler, design and construction of the improvements to the treatment plant have been right on schedule. Water, for example, had to be flowing to the cogen plant by November 1, 2000. “With the efforts of the city and IMCO,” he said, “that important milestone was met. We were on target.”

And, added Ronald Walz, Senior Engineer for Brown and Caldwell, “even with all the unique design and construction issues in this innovative project, change orders were less than 1 percent of the budget for the treatment plant.”

One of the Greenest Projects Ever

Walz called it one of the “greenest” projects he had ever worked on. Advanced combustion technology, for example, will contribute to the plant’s overall fuel efficiency of 62 percent-almost twice the efficiency of a coal-fired plant. But from Walz’s perspective, “the wastewater treatment plant and the cogen plant have been designed to make the most efficient use of resources while minimizing the impact on the environment in every way possible.” This project even received the Governor’s “Sustainability Award” for the year 2000.

IMCO President Frank Imhof said cooperation and higher standards made the difference in the WWTP portion of the project. “The entire project has so many unique, trendsetting aspects to it that it is a privilege to be able to provide our expertise,” said Imhof. “The team effort by the design engineer for the WWTP, Brown & Caldwell; the construction manager, URS/O’Brien Kreitzburg and the city of Klamath Falls has made this project successful. Their attitude to digging in and getting the job done minimized some of the project difficulties. Their partnering approach to construction management allowed for the project to be completed on time and within budget.”

A Revenue Source, Too

A moneymaker? That’s what city officials expect. Once the cogen plant is on-line, the city of Klamath Falls will also be able to participate in revenues generated by the cogen plant. Depending on market price of the electricity and once the bonds are paid off, the city could financially benefit up to $10 to $15 million per year-which is more than annual revenues generated from property taxes.

“Because the cogen plant is owned by the City,” said City Manager Jeff Ball, “it will realize the profits made by the plant. In the first few years, the City expects to make approximately $3 million with additional revenues going to early retirement debt retirement. The City will be use its project revenues in part to reduce taxes, build city services and improve the parks. In addition, the revenues will be used to encourage economic development by providing low interest business loans and installing new infrastructure.”

Prospects for the Future

This project we have been on incorporates many important environmental components as well as technical innovations and is setting a new standard in collaboration between private and public sectors; and between industrialists and environmentalists. In providing efficient power generation while improving water quality and use, the project serves as a model to many communities who strive to provide the best available stewardship of their resources.

By all accounts, this project has, even with its challenges, proved to be very successful-so much so, that currently the City is beginning the permitting process for another cogen plant at the same location. It will be smaller in size and output, but will add to the large and progressive thinking of this small community. As our previous City Manager, Jim Keller once put it, “Klamath Falls is a great community with very special people in it. While it is small in size, it thinks big.”

The Klamath Falls project has gone on to receive national attention for its unique blending of engineering disciplines, “green” principles and political initiative. Working in conjunction on this article were Mike Kuenzi, P.E., Director of Public Works for the city of Klamath Falls; Todd Vasey, Project Manager for IMCO General Construction in Bellingham, WA; and Mike Gowan, Senior Project Manager and Technical Writer for Baron & Company