DULUTH – Duluth is set to impose a new surcharge to pay for $42 million in federally mandated repairs to its water system — one of the state's most complex and one chronically plagued by water main breaks.

However, city officials say residents will likely see a negligible increase, as a different water surcharge expires this year.

The Environmental Protection Agency inspected the system in 2023 and found many "deficiencies," although none that affected water quality, city officials said. Plans to address the issues were in the works before the inspection, but the timeline is accelerated because of the mandate.

Since 1898, a pumphouse situated on the shore of Lake Superior has drawn water from a 60-inch pipe that travels a quarter-mile out into the lake and about 70 feet down. Divers regularly inspect that pipe, and it is sound, but the 127-year-old pumphouse needs $3 million in repairs, including a new roof.

The most expensive of the projects includes rehabbing five large water filters in the water treatment plant and building one more for $11.5 million.

About $20 million will go toward major reservoir improvements. The city, which also sends water to Proctor, Hermantown and Rice Lake, manages 433 miles of pipe, 15 reservoirs and 11 pumping stations, with 9.7 million gallons pumped through daily.

Duluth's old pipes and frequent freezing weather contribute to breaks, but its steep hillside and long and narrow topography are the reasons for so many reservoirs and pumping stations. They're needed to move water upwards of 1,200 feet, said Howard Smith, chief engineer for the city's public works department.

"We're essentially pumping up a small mountain, compared to everyone else," he said. "If we were a flat city, we may only have two or three storage facilities."

Duluth's different pressure zones mean there is more infrastructure to maintain, and half of its system is more than 90 years old. A couple of pumping stations need to be replaced.

Public works director Jim Benning told the City Council at a December meeting that the water surcharge for its nearly 29,000 customers would run for 20 years but could be reduced by seeking new bonding money from the state.

Some of the necessary work is already done, as the city allocates $4 million each year for water infrastructure.

The EPA's biggest concerns involve the system's physical components, and nothing in its order indicated water quality was an issue, Benning said.

"We have and continue to have some of the best water in the world," he said.

The new rate is expected to take effect in May and garner $3 million annually to pay for work. A monthly federal clean water surcharge of $4.90 ends this spring, and public works officials say the new charge for the largest group of water users — single-family homes — will be about the same: roughly $55 annually.

The city is holding several informational meetings about the surcharge next week, and the City Council will hold a public hearing in March.