Sewer Overhaul Moves Ahead After Federal Suit

by kespeland on December 3, 2007

Jefferson County’s Metropolitan Sewer District is entering the next phase of a major project to upgrade its sewer system. The goal is to curb the millions of gallons of untreated sewage that spill every year into local waterways. WFPL’s Kristin Espeland reports.

The plunk of fat raindrops hitting the ground may be music to the ears of gardeners. But that sound sets off alarm bells at the metropolitan sewer district, or MSD. Rain can overwhelm the city’s treatment plants. Most of the older parts of Louisville, inside the ring of the Watterson Expressway, use a combined sewer system. The system takes everything, from what you flush, to storm water run-off, in a single pipe to the treatment plant. Combined sewers were the best technology available at the time they were built, starting in the 1860s. But what the pipes and plants can’t handle gets released straight into the Ohio river. That’s not ideal… but in wet weather… it’s legal. Beneath most of the city’s newer neighborhoods are separate sewer lines and stormwater lines. What’s illegal is when sewer-only pipes overflow, which is exactly what’s been happening along Beargrass Creek.

“We’re talking about a total discharge of somewhere in the 150 million gallons per year range.”

That’s MSD contractor Gary Swanson at the agency’s headquarters. Neighborhoods like Beechwood Village across from the St. Matthews Mall have separate sewer lines. And when it rains, groundwater seeps in and overwhelms the system. So a flap at the end of the pipes flips open to let the extra flow escape… right into the creek. Now, under the terms of a federal law suit, MSD must stop these illegal discharges from the four worst sites…. immediately. The suit, filed by the environmental protection agency and the state of Kentucky in 2005, forced the city to tackle the worst of its sewer problems right away and then turn its attention to the rest of the system. Engineers are hitting the drawing board now to hit the first of many mandated deadlines. It’s the beginning of one of the largest public works projects the city has ever seen. Engineer Gary Swanson says the problems they’ll address, first, in Beechwood Village, go back decades.

“That whole subdivision was constructed in the 1960s… never been able to make them perform properly.”

The solution, Swanson says, is a brand new sewer system for the area. And if you live there, here’s what that means.

“Replacing the entire sewer system means… we’ll be in every house…every yard… and every street in beechwood village.”

And that’s just a fraction of the federally-mandated fixes MSD must make. The agency owes a plan to address the rest of those fixes throughout the entire sewer system to the Environmental Protection Agency by December 2008. And the work is estimated take nearly two decades. Most of the problems are those legal but undesirable discharges from the combined sewer system. Ideally, in wet weather, all the sewage and rain water would flow together to one of the two major treatment plants, get treated, and then released into the Ohio River. But a visit to the Morris Forman sewage treatment plant near Rubbertown reveals why that isn’t always the case.

“We have two flow streams…”

Engineer Alex Novak starts the tour from where combined sewage flows in to the treatment plant. Every gallon of this smelly brown sludge…in dry weather… will make about a three day journey through a maze of gates and sieves and tanks.

“So the flow goes over here…”

Each step essentially removes more and more of the solids…including one turn through a special tank that employs bacteria to munch through those solids more thoroughly. The whole plant can treat around 300 million gallons a day. But when it rains or snows, and more flow is gushing in to the plant faster than it can treat, some of these treatment steps get bypassed. Every drop will be sanitized with chlorine, but some solids will make it into the Ohio. And on the way to the plant, pipes throughout the combined system could overflow straight into the Ohio before treatment…legally…at more than a hundred combined sewer overflow sites around the city. Luckily, that’s not the case on this day.

“So you can see at this point…”

To reduce the number of overflows, MSD will try out a range of techniques. One involves trapping overflow that might have escaped in a section of giant sewer tunnel. Back at the agency’s headquarters, engineer Angela Ackridge explains.

“What we have already done …until Morris Forman has the capacity to treat that flow completely.”

To date, Ackridge says, this storage system has kept nearly 600 million gallons of untreated sewage out of the waterways. But it’s going to take more than that to control the problem. MSD will be separating some combined sewer lines. It will add pipes to increase the system’s capacity… and it’s enlarging a second treatment plant to be able to handle more volume. The price tag… now… is $800 million dollars. Regulatory director Brian Bingham explains how much of that will come from the rates customers will pay.

“100 percent or close to it….spending about a hundred million a year.”

How the city got to this point is a long story. Some parts of the sewer date back to civil war times. Some fragments of pipe still in use are made of wood. But as for why it took a lawsuit to force MSD to clean up the system’s major messes, Bingham says it took a lawsuit to justify the more expensive projects. He says the agency has already made several improvements…including upgrades to the Morris Forman plant. But he says they’ve moved slowly on other projects to avoid upsetting customers.Downtown sewer, 1937. Credit: MSD

“One of the things we’ve tried to balance…improvements in water quality.”

That balancing act might have delivered cheap sewer service. But it seems to have come at the cost of clean rivers and creeks. Now, the city must pay up.

Listen to the story.

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