Grease down the drain 'doesn't just go away;' grease abatement costs Grand Forks upwards of $200,000 a year

May 11—GRAND FORKS — Putting grease in kitchen drains or so-called "flushable" wipes down the toilet usually results in one outcome: Someone from Grand Forks Public Works will have to clean it out.

"... It doesn't just go away," said city water operations manager Dan Hanson. "Some person has to clean it out because it doesn't make it all the way, because it's not meant to go down."

The grease — as well as the debris it collects — gets caught on grates and coats the pipes in lift stations. Grand Forks' 46 wastewater lift stations are the first stops before the wastewater goes

to the wastewater treatment plant,

on the northwest side of the city. Putting grease, flushable wipes and similar things into the sewer causes headaches for public works employees, since those products don't break down as readily as toilet paper.

According to a September 2023 report given to the Grand Forks City Council

when it amended the wastewater fees and ordinance for fats, oils and grease abatement,

some lift stations are requiring weekly flushing to keep them clean of obstructions. Two of the biggest culprits are grease and wipes.

"The grease attaches to the wipe and vice versa. (It) just seems to become a problem together," Hanson said. "When plugged up with rags during a heavy rain event down in the downtown area (for instance), we would have serious problems."

Together, they cause damage to the pumps that make the system work.

"Over time, you get damage to the seals (of the pumps)," said Pete Aamold, wastewater and stormwater supervisor for the city. "(Last week) pretty much all our pumps were down at one time at (one of our) booster stations, which isn't good."

According to Aamold and Carmen Syverson, utility engineer for the city, the station's pumps were clogged with a "big log" of wipes that took more than five hours and four people to remove.

Booster stations, or master lift stations, collect the wastewater from lift stations throughout the city and boost the wastewater several miles out to the wastewater treatment plant. If the damage caused by the grease and wipes means the pump needs to be replaced, it can cost upwards of $60,000.

Even if the pumps aren't damaged, it still costs the city money. In 2021 — the most recent data available — public works estimated that it cost $213,024 to clean the city's sewer from fats, oils and grease. Since 2009, the city has charged food service establishments a fats, oils and grease fee, often referred to as a FOG fee. Many establishments are required to have a grease removal device, but issues remain, especially for residential areas and older areas of the city.

"Lift Station 5 in downtown right off Third Street. That takes a lot of the flow from downtown," Syverson said. "If there was a break or if the pumps back up, it's either going to the river or into people's basements."

The city is working on building redundancy with an additional force main to service the area. Additionally, the older clay pipes in the area tend to cause more issues compared to the newer plastic ones.

The other issue spots in the system are those that take wastewater from the main commercial areas along 32nd Avenue South and Washington Street and where the highest density of people live.

The FOG fee charged varies based on the type of food service establishment. Restaurants, gas stations, hotels, churches, and large apartment complexes pay a fee with their wastewater bill to help fund cleaning costs. The amount varies based on the type and scope of the establishment, between $5 to $80 dollars monthly. In 2024, the city expects to generate $115,944 from this fee.

Aamold also said the modern low-flow fixtures may be contributing to the issue, since less water overall is going through the system. The grease in the city's sewer is like cholesterol in arteries, building up and coating the insides until no more can get through.

Hanson said when a resident cooks bacon, the leftover grease is in liquid form.

However, "if you let it sit there for an hour, it's solid. And then when it gets down the pipe, it gets solid as it cools off; all that stuff should just go in the trash," Hanson said.

Syverson added that "just putting it down your garbage disposal and praying it goes down doesn't mean it should."