Sean C. Morgan
The Sweet Home City Council last week authorized Public Works Director Mike Adams to move forward with a study to improve energy efficiency at the city’s water and wastewater treatment facilities.
The study will cost about $8,000 with funds provided by the Energy Trust of Oregon. The work will be completed by BacGen Process Technologies.
“They’ll come in and take a look at our processes and make recommendations for energy changes or upgrades to the system in an attempt to have a payback in energy savings in 18 months,” Adams said. For example, the study may suggest replacing one type of pump with an energy efficient pump.
The city is required to implement at least one recommendation of BacGen or it must pay back half the cost of the study, Adams said, but the recommendations for changes should pay for themselves in reduced energy costs.
BacGen virtually guarantees any recommendations it makes will result in savings if implemented, Adams said, “even if it’s just to say put a lighting control (a light motion sensor) on this office.”
BacGen will look at the city’s average daily flows and energy consumption, inventory equipment and tour the facilities.
To spend money on new equipment and save money, “the first thing I’ve got to do to justify spending the money is tell people what they’re getting for it,” Adams said.
Public Works staff could figure out what might improve savings, but this does it at no cost to the rate payers of Sweet Home, Adams said. Part of the city’s agreement with the Department of Environmental Quality is to look at ways to improve the wastewater treatment plant. Recommendations could help meet the agreement’s requirements.
While preparing for the study, the city is moving forward on the second phase of a demonstration project to reduce inflow and infiltration.
Inflow and infiltration (I&I) is water that works its way into the sewer system through leaky pipes or cross connections. During heavy rains, the wastewater treatment plant may handle more than 20 million gallons per day forcing it to bypass untreated wastewater into the South Santiam River.
The city entered into an agreement with the DEQ to reduce I&I flows by 2007 and stop discharging untreated wastewater into the river.
The second phase of the project is in the planning and design phase now, Adams said. The first phase of the project, a $1.4 million project, is underway.
He asked the council for a policy decision on how the project would work. In the first phase, the city is replacing private lateral lines all the way to homes.
In the second phase, laterals will be replaced only in the public right of way and in easements, according to the council’s decision last week. Private laterals past property lines will remain the responsibility of property owners in the project area.
The demonstration project is aimed at developing a better picture of the I&I problem based on how flow data changes following the project.
In the first phase, the city has completed replacement of three sewer main lines and is in the process of replacing laterals in three areas.
Once flow data are available, the city will be able to figure out the most cost-effective way of reducing I&I, whether replacing main lines or laterals or increasing the capacity of the treatment plant.
At some point, the council will have to make a policy statement regarding replacement of private laterals, Adams said. For the moment, the city is spending money on private laterals. When a larger project is designed, the council will need to decide how to replace laterals, particularly how to fund it.
Under city codes, property owners are responsible for their laterals all the way to the main line, Adams said.
Adams hopes to have definite costs for the second phase by the Jan. 13 council meeting. He anticipates costs for the project will be about $1.7 million.
The first phase and second-phase design are being funded by a low-interest DEQ loan.
The city is putting flow monitors in now to begin gathering data on how the new lines have changed I&I flow.
Adams does not anticipate that the project will reduce flows at the plant. Storm and ground water will still get into the system, just farther down the line.
The data should show how the replacement projects have reduced flows in specific areas though and help develop an idea what it will take to reduce flows overall.
In any case, the replacements in the demonstration projects will need to be completed at some point before the agreement deadline in October 2007, Adams said. “We might as well get started now.”
The projects will show the city is aggressively attacking the problem, possibly providing leverage for a deadline extension if necessary and leverage for grant funds or even direct appropriations by Congress.