The Alaska Rural Water Association (ARWA) has named Petersburg Alaska's Wastewater System of the Year for 2022.
"Petersburg stays on top of routine maintenance and keeps their certifications up to date. Not everyone does that," said Mark Wuitschick, who nominated Petersburg and works at ARWA as the Wastewater Training and Technical Assistance Specialist.
Petersburg also goes beyond the minimum requirements, and the award highlighted efforts at composting removed solids, which the Petersburg wastewater utility has done since 2015. This diverts approximately 40 metric tons from the landfill to the waste soil disposal site, with the potential of selling it as fertilizer in the future.
"Fairbanks has been selling theirs for years. If they can do it in the cold up there, we can handle some rain," reasoned Wastewater Operations Supervisor Justin Haley. He usually keeps tarps over the pile and injects air from underneath. He maintains a 4 to 1 ratio of woody debris to waste solids and monitors the temperature to decide when to turn the pile over with a front-end loader. "The hotter it is, the more we can turn it. It has to be at 60 degrees Celsius (140 F) for over a week to kill the bacteria. Then it's safe for a garden, but some people still don't like the idea. I guess they don't care in Fairbanks though." Though just in case the mention of composting stirs community interest in expanding Wastewater's program to include accepting compostable household scraps, Haley explains that wouldn't be doable at this time due to staffing and time constraints.
Inside the treatment plant's control room, a large monitor displays the status of the 20 lift stations in town, all with at least one green light indicating an operational pump. "Gravity does most of the work, but then there are lift pumps to move the waste out of lower areas," explained Utility Director Karl Hagerman. "Almost everything goes through the pump at the Whale Observatory, then it comes here."
The monitor displays how many gallons per minute are coming into the plant and tallies the total for the day. "About 250,000 gallons is typical for a day," Haley said. "If there's much more than that then we know we're getting extra from somewhere." On a rainy day, Haley said, runoff can enter the system through the little holes in manhole covers, cracks in concrete manholes, cracked pipes, or some low-lying areas where gutters must drain into the sewer. Rain on snow made for one day of 1.9 million gallons last year, approaching the plant's daily capacity of 2.1 million gallons. "Excess water is our enemy," Haley said.
Haley is onsite almost every day. "There's someone here seven days a week," he said. "Even on Christmas, I'll come in for a couple hours to check on everything."
Round-the-clock staffing could be required in the future since the EPA will be conducting a review to see if secondary treatment is needed in Petersburg. If required, the extra equipment could cost around $20 million and would require staffing around the clock. Said Hagerman, "We don't want people to have $100 dollar a month water bills, but if we have to pass along the cost, it could be that much or more."
Despite disposing of the solids in a safer and cheaper way, the treated liquids are still emptied into Frederick Sound without a full disinfection process. Hagerman says the plant was originally built with disinfection equipment, but it never worked properly. The city later sued the manufacturer and removed the equipment, obtaining a 301(h) waiver which allows for less than complete secondary treatment, or the process of disinfecting the water that comes out of the plant.
Wrangell recently applied for a renewal of their 301(h) designation, which has been tentatively approved. Petersburg will likely be asked to renew soon, along with most other towns in Southeast. The 301(h) waiver applies to many coastal towns that discharge into marine waters where deep channels and tidal mixing provide adequate dilution. Even Anchorage is part of the 301(h) program.
The Petersburg wastewater plant has its own lab, complete with Erlenmeyer flasks full of colorful liquids and a clipboard with a built-in calculator. "We spend two or three days a week in here," says Haley. They're responsible for collecting approximately 300 tests per year, ensuring that the impact on the water quality of Frederick sound remains minimal.
Four treatment processes occur at the Petersburg plant. First, water passes through a pair of rotating stainless-steel screens that scrape off much of the larger debris such as food waste and paper towels. Next, grit is centrifuged out, including sand, clay, and other inorganic material. The grit gets pushed through a tube into the next room by a long auger, wringing most of the water out of it. After a time in a settling tank, the sediment travels up a bucket conveyor, like a small-scale mining operation. "Oh there's gold in there," said Haley, possibly seriously. The sediment goes to the compost pile, while the water goes back inside to the digestor, a room-sized tank where warm air is blown through the water to aid the natural decomposition by bacteria.
The next stage is a calmer pool called the clarifier, with slowly moving oil booms skimming grease and other floating material from the surface, then sinking to again remove sunken sediment from the bottom. Finally, the semi-clear gray water goes through one more settling tank, then to the outfall in Frederick Sound.
"The biggest problem we have is flushable wipes," says Haley. "Nothing jams up the machinery like them. We've put out notices in the paper, and it might help a little, but not for long. Grease is the other thing that plugs up the pumps. Combined they're like concrete." Toxic, corrosive, or flammable materials shouldn't go down the drain either.
After going through the digester tank where bacteria aid the natural decomposition processes, the water rests in clarifier pools where slow moving booms skim grease and other floating material as sediment settles on the bottom for removal.
Around the outside of the building, a pit covered with a steel grate is where the town's Vactor truck dumps waste from all the vault toilets at campgrounds and day-use areas. A utility worker hoses the material through a grate to mix it well enough to be pumped into the plant. Material is brought to the pit from the landfill when they clean out their collection trenches. And waste from cruise ships is also brought here which can be an added burden on the plant's capacity.
It's not glamorous, but the wastewater utility is a crucial element of Petersburg's quality of life. It's one of those underpinning systems that are hardly visible and easy to take for granted until something goes wrong. That Petersburg's system was named best in the state is something the community can take pride in, but for the utility workers the goal is simply to keep the system running smoothly. In fact, until the Pilot reached out for an interview following a press release about the ARWA award, the wastewater team was entirely unaware that they had received the statewide recognition.
The next time someone from ARWA is in town the award will be presented.
Read more news from my hometown at www.petersburgpilot.com