Accessing the Williamsport Municipal Sanitary Authority Central plant headworks' inner sanctum requires walking down a flight of 66 steps.
When the door slams, it shatters nerves.
The building recently became operational, and the authority offered the Sun-Gazette an exclusive tour.
Engineer Jeff Wilkes explains how the secondary clarifier tanks work during a recent tour of the Central Plant.
"We can now significantly reduce the occurrence of overflows during storms," said Douglas E. Keith, authority executive director, during a tour of the plant to describe milestones in the $120 million upgrades.
Valve to vintage pumps closed
Recently, the authority closed the valve to its vintage 1955 wastewater pumping facility and directed sewer flowing from the city, Loyalsock Township, South Williamsport and a portion of Armstrong Township into the headworks building.
The headworks - called that because it is the first place sewage water arrives - houses six pumps, electrical panels and equipment that cleanses the water of hair, particles and grit. It cost $20 million to build.
"It's part of a $120 million upgrade to the authorities' two treatment plants," Keith said.
The construction upgrades have been ongoing for several years after the authority was told it must comply with U.S. Environmental Protection Agency and state Department of Environmental Protection mandates linked to cleaning up the Susquehanna River basin and Chesapeake Bay.
Due to the upgrades the authority has raised rates over the past five years to pay for the majority of the construction. The environmental cleanup requirements are designed to reduce wet weather overflows into the river and decrease nutrients entering the bay that kill aquatic life, Keith said.
4 stories under ground
"We're four stories below the surface," said Jeff Wilkes, an engineer with Malcolm Pirnie, project engineer, who offered most of the technical information on the tour.
Half of the building is buried far below the surface, tied down and secured there by steel pipes buried 30 feet in the ground to hold the room in place.
"Each of the six, 150-horsepower pumps can take 10 million gallons of sewage a day," Wilkes said.
Another 200,000 gallons of water can be stored in a well behind the wall where the pumps are at in the other side of the building, he said.
Massive electrical gear feeds power to the pumps. The automated system adjusts speed of the pumps to optimize energy use. The building is divided into a dry area, where electrical equipment is stored, and one where the wet sewage is raked clean through screens.
On average, 21 million gallons of sewage flow into the plant each day. Sewage and water collected are either conveyed on to additional cleansing processes or - when flows exceed 21 million gallons - pumped to the wet weather storage tank.
Not for swimming
Nobody would want to take a dip in this tank, however, as a combination of fluids, solids and floatables require the uninitiated to quickly get adjusted to noxious odor.
"In the past, this would flow into the Susquehanna River," Wilkes said.
When the inner tank is low, the sides are washed down, he said, evoking laughter among those on the tour when Wilkes was asked, "Who gets that job?"
The tank, combined with storage under construction in Loyalsock Township and South Williamsport, will allow more than 8 million gallons of additional wet weather flow volumes to be stored for treatment in the plant until the storm peak flows subside, Wilkes said.
The headworks facility operates primarily on automated equipment, but electrical generators are capable of operating it during power outages. Staff can manually control the units.
"Large debris can mess up the pumps," Wilkes said, pointing overhead to show where the sewage from the city, South Williamsport and Loyalsock Township arrives.
Water goes through process to remove stones and grit. Solids are collected and taken to the Lycoming County landfill, Wilkes said.
A centrifuge spins continuously to remove the grit in tanks that can be accessed by lifting heavy parts of the floor.
"When we remove the grit, it increases the life expectancy of the equipment," Wilkes said.
The next phase involves water heading to the clarifiers. These are large, circular pits with a screen that spins.
"Anything heavier than water drops to the bottom," he said.
The wastewater still has materials in it that should not go into the river. Micro-organisms that eat solid materials are grown and added. Further clarifying occurs as these "organisms," or "bugs," drop to the bottom to eat more of the unwanted material.
Should there be a power outage, two diesel engines are capable of running emergency generators on the site.
The site includes a central office building where employees can put their belongings in lockers and engineers have offices.
As the tour ended, the officials spoke about additions to the project that include the completion of four new final clarifiers, a biological filtration facility for reduction of nitrogen nutrients, a chlorine contact disinfection tank, additional chemical feed equipment for phosphorus removal and upgrades to the aeration system.
Still to be added is equipment that includes a gravity belt thickener for improved biosolids handling and buildings to house a laboratory and administrative facilities.
The West Plant, the city's other sewer treatment facility, also will receive upgrades to the existing plant structures and a new headworks building.
Most of these facilities will be brought online next year, and officials anticipate final completion of the multi-year project in late 2014.