Success Stories
Taking a closer look saves dollars and energy
at Carbondale wastewater plant
Treatment plant operators improve savings with new energy monitoring systems
By Suzie Romig & Heather McGregor
Clean Energy Economy News
Carbondale’s wastewater treatment plant operators are building on their success in saving energy with a new set of tools: tracking the plant’s electric usage on a daily basis, and acting on recommendations in a technical energy audit.
Town of Carbondale Utility Supervisor |
The wastewater treatment plant, the single largest energy consumer in the town government’s portfolio, had already cut its energy use by about 30 percent thanks to changes implemented about five years ago. Now Carbondale Utility Director Mark O’Meara and Utility Supervisor Ralph Bryant are tightening the energy use screws in hopes of cutting energy use by at least another 10 percent.
This focused attention on the plant’s operations is expected to boost overall plant efficiency enough that the town can drop its plans for a $15 million plant expansion. Instead, the town is spending about $1.4 million on improvements that have high payback potential in energy savings. The funding includes a $500,000 grant from the Colorado Department of Local Affairs.
In addition to saving energy, the ongoing improvements at the wastewater plant have saved staff time and reduced the use of processed water. Town officials say the process has improved the quality of effluent going back into Roaring Fork River, so that a cleaner energy solution is also resulting in cleaner water.
Interval meter tracks energy use
Plant operators can track the plant’s electrical use on a daily basis now that an interval metering system is in place. Installed in September 2009, the interval meter sends a signal every 15 minutes via phone line to Automated Energy Inc. in Oklahoma City. The interval data then is retrieved by New Energy Technology (NET) in Grand Junction and fed into a website.
Plant operators can log on to the site, read the previous day’s interval data graphs and monitor the plant’s electric usage. The interval data, O’Meara said, “will show where we have aberrations in operations. Say a pump is cycling too much, it will show that.”
NET also posts the plant’s utility bills using EnergyCAP, an energy accounting software program. The energy tracking work by NET is funded in part by the Garfield New Energy Communities Initiative.
Energy audit targets plant upgrades
Earlier in 2009, Schmueser Gordon Meyer engineers (SGM) in Glenwood Springs conducted a comprehensive energy audit of the treatment plant. Originally SGM was called in to consult on a plant expansion. Instead, SGM engineers recommended a package of efficiency improvements.
The plant upgrades include:
- Installing a new air diffusion system in the digesters
- Replacing low-efficiency blower motors with high-efficiency motors
- Rebuilding motors and pumps
- Rerouting processes
- Incorporating automation at key locations
“It takes a lot of energy to put in a new building, and we would have been utilizing added equipment to run the additional process,” said O’Meara. Instead, he said, “We are reconditioning the plant, similar to rebuilding an old car, and reusing a lot of parts.”
O’Meara and Bryant have also focused on education and awareness for plant operators, creating a team approach to the energy-saving goal.
Plant improvements set a new baseline for energy use
Carbondale Wastewater Electricity Natural gas Total utility energy spending
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O’Meara said he is excited to see what happens over the next few months as the plant operators use the interval data and the EnergyCAP database to implement more changes suggested in the energy audit.
“If the operation is more efficient, the energy use will be more efficient,” O’Meara said. “The work that we are doing during the next three months will re-establish the baseline for energy use.”
He noted that the current budget crunch is “causing people to take another look” at what they can do cut costs in utility and industrial operations.
The EnergyCAP database information is also being evaluated by mechanical engineer Mike Ogburn, who works in energy tracking for Clean Energy Economy for the Region (CLEER) in Carbondale, the nonprofit that is managing the programs and services of the Garfield New Energy Communities Initiative.
Ogburn said one of the biggest challenges in helping towns meet their energy efficiency goals is having accurate, current data to analyze.
“Towns around the region have adopted goals to save energy and to reduce greenhouse gas emissions, but measuring progress toward those goals is difficult and often not put in place as part of the energy reduction plan. Very few communities have the systems in place to track progress toward those goals,” Ogburn explained.
“Now with both the EnergyCAP monthly database and daily interval data recording, the Carbondale wastewater plant team will be able to refine their processes from day to day. They’ll be able to continue meeting water quality requirements while driving down energy costs,” he said.