The lengthy process of constructing a new wastewater treatment plant to serve the City of Warren is nearing completion.

The plant, located on Harmar St., is set to be completed later this summer.

Department of Public Works Director Mike Holtz said that grading, seeding, fencing and paving are the major items left to be completed.

The new system went live in November and was built around the old plant. The return activated sludge plant built in 1956 and secondary biological treatment added in 1972, with the exception of a few digester and storage tanks, has been demolished.

“It’s getting there,” Holtz said, describing the project as “on the downhill.”

The old plant “just wasn’t in good shape,” he added, explaining that the pumps were inefficient and antiquated and that Department of Environmental Protection regulations have changed, resulting in the city having to treat more stormwater than previously required.

To counter that, the new facility will be much larger and will allow the city to stop using combined sewer overflows through the system, meaning high-flow periods will no longer exceed the system capacity and be discharged directly into the Allegheny River.

“Now we don’t do that,” he said.

The outfall pipe into the river was also raised eight feet as part of the project. Holtz said that at times when the river is high, the old pipe would be submerged, resulting in the sewage plant being unable to function. A 2011 incident resulted in the plant being shut down for a month.

The new plant includes a new control building, pump system, a lab for testing materials and a sludge dewatering system, which the city has been contracting out.

Holtz explained that each room has computer panels which allow operators to know what is occurring throughout the entire plant, whether on-site or accessed remotely.

Other improvements are incorporated in the treatment process. Holtz explained that mechanical screens in the new plant filter out much more of the inorganic material than the old ones. Before, the material passed through the screens and “wrecked the pumps.”

Additionally, due to increased capacity, the water will be able to be treated over a longer period of time at a few stages of the process, allowing the sewage to be more thoroughly broken down and filtered out of the water.

The two digesters used in producing sludge as well as an aeration tank that was converted into a digester are all that remain of the old facility in the new plant.

Holtz said that the city used to utilize a contractor to press sludge and “in the end, it is cheaper” to do it in house, in addition to providing better “operational control,” meaning the city can press sludge when it wants to or needs to to free up space, rather than on the schedule of a contractor. He said the prior contract cost several hundred thousand dollars each year.

Additional savings are maintained by continuing to run all lab tests in house.

While some operational savings will be realized, Holtz said additional staff will be needed to run the new plant.

“We only ever had two full time people here under the old plant,” he said. “That number will increase,” citing the increased size of the plant resulting in more to maintain.

Warren City Council approved a state grant and loan package for improvement work on the city’s wastewater plant for the project that was estimated to total $24,525,000. The city was awarded a $4,508,277 grant through the Pennsylvania Infrastructure Investment Authority (PENNVEST) program. Additional project costs include an approximately $525,000 local contribution.

Holtz said that project came in as budgeted with “nothing that wasn’t really foreseen.”

How long will the new plant last?

That’s impossible to project.

Holtz said that he wants to see the plant outlive the life of the loan 20 years but added that the old plant ran for 40 to 50 years.