on to switch sewer service mechanics in McCormick Woods homes is moving — or STEPing — slowly along.

Known as the McCormick Woods STEP System Retrofit project, city officials are hoping to gradually convert homes in McCormick Woods from the existing septic tank effluent pumping system to a more manageable grinder pump system.

The STEP systems, installed in more than 600 McCormick Woods homes, are a combined storage tank and pump sewage system. Liquid effluent is drawn to a city sewer line while solids are stored in home tanks that the city pumps on a five year cycle.

Problems with the McCormick Woods STEP system are numerous, said Rob Putaansuu, city council member and chair of the city’s utility committee. Effluent from the system is corrosive to the city’s sewer infrastructure.

The city spends about $70,000 a year to pump out home septic systems and perform other regular maintenance to the system. The STEP systems are commonly clogged with feces, clothing and other foreign objects.

The most worrisome problem for McCormick Woods homeowners is effluent from the sewage pumped to a tank near the entrance of McCormick Woods emits a powerful odor, especially in the warm summer months.

“The homeowners’ biggest issue out there is the odor caused by the STEP systems,” Putaansuu said.

The city has gradually tried to ween McCormick Woods residents off the step system to a different pumping system more in line with the remaining city homes.

In 2011, letters were sent to 60 McCormick Woods homes outlining the STEP problems and asking the residents if they would voluntarily switch over to a grinder pump sewage system that would eliminate the problems caused by the STEP systems. In the letter, the city said it would pay for $6,000 per-home conversion cost.

But after the letter was sent out, the city hit a few roadblocks. First, the bids the city received from companies slated to perform the STEP system retrofit were higher than expected, and needed to go out for rebid. Of the 60 letters that were sent out, only 22 homeowners responded and said they would voluntarily make the switch.

Dick Ziglar, a McCormick Woods resident, said he wasn’t mailed a letter last year, and doesn’t know if he will voluntarily switch sewage systems when the time comes.  Unlike other city residents, McCormick Woods residents pay nothing to have their septic tank pumped and all maintenance comes from the city right now, he said. Converting to the grinder system would eliminate the need for a septic tank pump every five years, but Ziglar would be fiscally responsible for maintenance and replacement of the grinder system.

“At the moment I have a system that costs me zero dollars,” Ziglar said. “If I went to the grinder system, there could be some cost for that system.”

The cost, Ziglar said, would come in replacing the grinder pump.

Best estimates show grinder pumps cost $2,700 and need to be replaced every 10 years. The initial pump would be installed by the city, but after that, it’s up to the homeowner to replace them.

Ziglar said he understands the city is trying to preserve city infrastructure and mitigate odor by trying to have homes in McCormick Woods switch to the grinder pump.

Putaansuu and the city have responded to every question Ziglar has had, he said, and have been very helpful in providing information about making the switch.

Ziglar said ultimately, for the good of McCormick Woods and the city, it would be better to switch to a grinder system before the corrosive effluent wore through the city’s sewage infrastructure and sewer rates city-wide skyrocketed to replace the damage. But it’s hard to make that decision when the fiscal incentive to replace isn’t there at the outset.

“It is a somewhat expensive grinder,” he said. “At some point it would need to be replaced.”

Putaansuu hopes with a new bid, the city can start work converting the 22 homes that agreed to move to a grinder system sometime this year. He thinks once those first homes are converted, and yards are intact afterwords, other residents will recognize that converting is the right thing to do. The city had originally hoped to have all of McCormick Woods converted to a grinder system in 10 years. That estimate is a little behind now, Putaansuu said. But he holds out hope that the STEP system and its problems, will eventually be gone for good.

“At some point, we’re going to run a normal sewer out there,” he said.