The Butler Area Sewer Authority's new $40 million storage tanks have not eliminated all excess sewage overflows.

At least not yet.

Tom Rockovich, executive director of the sewer authority, said the overflow tanks were activated six times in the past year.

During three of the activations, the two overflow tanks at the corner of South Monroe and East Cunningham streets reached their maximum 1 million gallon capacities, causing untreated waste water to flow into the Connoquenessing Creek.

“We've had some issues at Monroe,” Rockovich said. “We've in the process of making repairs.”

Rockovich attributed the overflow to mechanical problems with the pumping station near the Monroe Street tanks.

“The problem is the pumps are not operating at their peak level,” he said. “So the water is not flowing at its maximum capacity.”

The slow flow is leading to more backups at the station, causing the overflow tanks to take on more water.

“We're about halfway through with the repairs,” Rockovich said. “We're supposed to be done by early summer.”

The other tanks' capacities range from 3 million to 4.3 million gallons.

The first tanks were completed in April last year, while the final tanks were done in August.

Another issue with the Monroe Street tanks stems from a previously unknown overflow site in the area.

Rockovich said contractors found the overflow while building the tanks.

“No one even knew it was there,” he said. “But it added even more additional flow demands that we had not planned for (when designing the tanks).”

Rockovich said each of the tanks was designed based on past records of flow through the authority's system.

The other tanks, which were activated on five of the six occasions, have worked fine, Rockovich said.

“They've worked as designed,” he said, adding the tanks have reached about half their limit. “It shows we have some additional capacity and can contain the water levels in the area.”

The storage tanks were a requirement of the state Department of Environmental Protection.

DEP issued a consent order to BASA and the municipalities using the service in October 2006, mandating the authority eliminate sewage overflows into creeks and streams. DEP did this by limiting the number of sewer connections that BASA could give to developers.

The order was lifted in November.

That meant developers could apply directly to BASA for sewer connections instead of first going through a multistep process for DEP's approval.

Rockovich said the tanks were recently inspected by both DEP and the U.S. Environmental Protection Agency because BASA received grant money from the Pennsylvania Infrastructure and Investment Authority.

“They were satisfied with the progress we've made,” he said.

The authority's system averaged 12 to 18 overflows per year before the addition of the tanks, Rockovich said.

Activating the tanks diverts flow from the pump stations and into the tanks, where it remains until the system is under less pressure.

Rockovich said the sewage could be stored for several days until the system is ready.

“Most of the time within a day or two we bleed it back into the system,” he said.

“Whenever snow is melting, the water just keeps coming,” he said.

“We try to empty it as quick as possible in case another event comes along,” he said.

Melting snow is what makes for the longest bleeding process.

Once the tank is cleared, it requires cleaning that can last a couple more days.

Rockovich said heavy precipitation is the cause of the problem.

“The combination of rain and snow melting is what causes the most trouble,” he said.

The new tanks were activated once last July following a heavy rainstorm. The other instances occurred during the winter.

Rockovich said the $40 million project has increased sewer bills by $5 to $6 per month for the average resident.

The authority originally expected rates to increase by up to $10 per month due to the project.

“Things worked out a little better than we expected,” Rockovich said.