Sewers overflowed in Duluth

Sewers overflowed in Duluth on Monday after another in a series of heavy rainstorms that has reversed a drought and even sent Lake Superior rising.

Water rushing over already saturated ground gushed into Duluth's leaky sanitary sewage system that couldn't handle the load, causing overflows at manhole covers and pumping stations, the usual bottlenecks in the aged system. It was the worst rash of overflows in two years, though city and sanitary district officials didn't have figures Monday for how much sewage was released at each site.

Meanwhile, some streets were covered by water as storm sewers also overflowed when too much rain fell too fast. City officials are asking residents and businesses to keep storm sewer grates clear of leaves to help keep the water moving.

Rainfall totals for Sunday and Monday were 2.87 inches along Duluth's Lakewalk, 2.57 inches in Proctor, 2.20 inches in Lakeside and over an inch at Duluth International Airport. Some areas in Wisconsin also were hard hit.

"We had reports of up to 3 inches in parts of Douglas County, with street and basement flooding in Superior," said Mike Bettwy, assistant forecaster for the National Weather Service in Duluth.

County Highway FF between county highways F and H in Douglas County was closed Monday due to flooding. Patrol Superintendent Keith Armstrong of the county Highway Department said water as deep as 6 to 8 inches topped one section of the road, which crosses through the towns of Maple and Brule.

In addition, Monday's classes were canceled at Wisconsin Indianhead Technical College because of a power failure.

Even giant Lake Superior is showing signs of recovering, shooting upward for the past three weeks as its watershed receives above-normal rainfall.

Superior now is out of record monthly low levels for the first time since mid-August and is even above the level at this time last year. The lake remains more than a foot below normal for October, however.

Some basements in Duluth flooded because of sewage backups, and some minor street flooding was reported, said Steve Lipinski, utility operations manager for the city of Duluth.

"We've got a number of basement calls [Monday] morning and we're following up to see whether it's the main lines backing up or just a local issue," he said, adding that several manhole covers had blown off but were quickly replaced.

At least seven sewage overflows had occurred in Duluth and Proctor early Monday, including at the Western Lake Superior Sanitary District plant itself. Peak flow at the plant hit 150 million gallons per day, compared to the average flow of about 38 million gallons per day, said Karen Anderson, WLSSD spokeswoman.

All that extra water comes from rainfall that seeps into the sanitary sewage system underground, often through home basement drains or pumps that are illegally attached to the storm sewer system. Leaky sewer pipes between homes and streets and under streets also allow clean water to infiltrate and overwhelm the system.

The extra water causes bottlenecks at pumping stations and where large pipes meet, sending a mix of rainwater and untreated sewage into the environment -- including streets, ditches, creeks and Lake Superior.

WLSSD reported overflows Monday at sewage pumping stations at 19th Avenue East and the Lakewalk, Fifth Avenue East and the Lakewalk and the Polk Street pumping station at 110 Central Ave.; and at manholes between 10th and 18th Avenues East near London Road and in a remote area of Proctor.

The city reported an overflow at 52nd Avenue East at Dodge Street, also at a pumping station.

The public is warned not to come in contact with sewage overflows, and advisories have been issued not to come in contact with Lake Superior water along Duluth's Lakewalk because of the likelihood of high bacteria levels. The problem will pass quickly with clear weather.

Efforts to fix the overflow problem include requiring homeowners to disconnect their basement drains from the storm sewer system.

Giant holding tanks and catch basins also have been built at bottleneck sites in the system to hold overflows so they don't run into the environment, and have reduced the overflow compared to similar rainstorms in the past. It's been clear during the recent wet spell, however, that much more work needs to be done.

The U.S. Environmental Protection Agency and U.S. Attorney's office are deciding exactly what to require of the city and WLSSD to fix the problem. The city and WLSSD have pledged to fix the problem by 2016 at a cost of about $135 million.

Over the past three weeks, Duluth has received more rain than in the previous three months combined -- about 6.8 inches since Sept. 18 compared to 5.73 inches for all of June, July and August.

Only eight days into October, monthly rainfall already is nearly 2 inches above normal in Duluth.

Duluth sits just over 3 inches short for the year, and the deluge over the past three weeks has erased nearly all evidence of the 16-month drought that ended in August.

Maria Lockwood of the Superior Daily Telegram contributed to this report.