Janesville official to ask city council for funds to upgrade waste treatment plant

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August 20, 2011
— Talk about turning lemons into lemonade.

Janesville’s utility director will ask the city council Monday to upgrade equipment at the wastewater treatment plant at a cost of $750,000. The equipment would allow the utility to at least double its production of electricity, create natural gas to fuel city vehicles and accept highly concentrated industrial waste.

Dan Lynch, utility director, estimates the investment could return more than $3.5 million to the city in the next decade.

Lynch said the technology is the “coolest thing since sliced bread.”

The projected savings eventually would include $60,000 per year in gasoline and diesel fuel after vehicles are converted to run on natural gas.

The $750,000 also would allow the utility to accept highly concentrated waste—such as byproducts from the production of ethanol and cheese—raising $146,000 in revenue.

The utility has created electricity from methane gas since the 1930s. At one point, it also experimented with fuel derived from methane to power vehicles, but the technology wasn’t mature.

As part of the not-yet-finished, $32-million revamp of the utility, the city installed micro turbines to replace methane-powered internal-combustion engines it had used to generate electricity.

“Before, you’d walk into the generator room and you couldn’t hear yourself think,” Lynch said. “It was noisy and hot. The engines had many moving parts, increasing the potential for needed repairs.”

The micro turbines that now drive the generators have one moving part.

Staff had no idea how efficient the new micro turbines would be, which is why they

are coming back to the council asking for additional equipment.

Lynch proposes spending $750,000 to buy:

--Gas conditioning equipment to convert methane into natural gas for vehicles.

--A natural gas vehicle-fueling station.

--An additional micro turbine to increase the production of electricity.

--Equipment to modify vehicles to run on natural gas.

--A station to receive highly concentrated industrial waste.

The plant spends $400,000 a year on electricity and $32,000 on vehicle fuel. Since the upgrade, it is producing $180,000 a year from electricity sales. The additional equipment would double the electricity produced.

“In the past, we used the electricity to offset the electricity we purchased from Alliant,” Lynch said. “Now, we sell our electricity to Alliant as a biofuel for twice the cost that they sell us their electricity for.”

The additional electricity is expected to create about $150,000 per year in new revenue.

Vehicle fuel savings would begin at about $8,000 per year but increase annually to about $60,000 per year over the next 10 years as vehicles are replaced with models that can burn natural gas.

Janesville’s plans impressed Dave Jenkins of the state Department of Energy. The city is hoping to get a federal grant for the project through the state.

“What they’re doing is very innovative, but it’s also very cost-effective,” Jenkins said.

A lot of renewable energy projects are expensive.

“This one makes a lot of financial sense,” Jenkins said.

The cost difference between using natural gas and petroleum or diesel is huge, Jenkins said. Petroleum is more than double the cost for the same energy.

“We’re excited about clean energy, especially if it can save consumers money and save companies and municipalities taxpayer money,” he said.

“And compressed natural gas—it definitely has the ability to do that.”

How it works

How does waste turn into energy?

It might sound like magic, but the process just mimics nature.

The solids from the wastewater coming into the facility are fed into anaerobic digesters, which are large, airless, sealed concrete tanks with steel covers.

The environment stimulates methane-forming bacteria. The bacteria use the sludge as food, and the byproduct is methane gas. The volatile components of the sludge, such as microbes and viruses, are destroyed.

“It’s basically like a really large digestive track for a mammal,” Dan Lynch, utility director, said. “What it does is the same thing that you and I do, only it does it on a much larger scale.”

The wastewater treatment plant’s purpose is to speed that natural process.

Once produced, the methane is cleaned and used to drive the plant’s micro turbines that generate electricity. The plan is to buy equipment to convert some of the methane into natural gas that could be used to run vehicles.

On the agenda

The Janesville City Council will meet at 7 p.m. Monday in City Hall, 18 N. Jackson St.

Items on the agenda include:

--A continued public hearing on an ordinance prohibiting possession of firearms in city buildings, with the exception of firearms carried by law enforcement officers.

--A public hearing on an ordinance re-creating electoral ward boundaries. The council in July created 25 city wards, but the state approved a redistricting plan that does not use wards as a base component of their assembly and senatorial districts. The city must change its ward plan and adopt an ordinance to conform to the state plan. The proposed ordinance modifies the previous ordinance by adding four wards and changing the boundaries of wards 11, 19, 22, 23 and 29.

--Action to create TIF District No. 35, which includes a 226-acre parcel on the southwest corner of Highway 11 and Beloit Avenue. The proposed district is being created to attract industry.

--Authorization to buy a vacant lot located at 1116 Hamilton Ave. in the Mole & Sadler’s subdivision. No building is allowed on the lot, and the owner bought it in 2004 before the flood plain issues were known. The owner paid $4,900 for the lot. It is assessed at $1,600, and the city has offered $2,000. The city would plant wildflowers to match other vacant land where structures used to stand before the 2008 flood. The wildflowers also help to manage floodwaters.

--Adoption of financial policies. The city manager recommendations include the debt limit be set at 2.5 percent of the assessed equalized value and the general fund debt be limited to 15 percent of the general fund operating budget. He recommends that the general fund reserve be maintained between 16.7 percent and 25 percent of the budgeted general fund operating expenditures.

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