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Overflowing problems
(by Tim Woodcock - April 29, 2009)
The Metropolitan Sewer District has a problem. In fact, it has several thousand miles worth of problems. To put it another way: the district has an unwieldy network of aging sewers, some of which dates back to the 1890s, but it does not have the money necessary to replace or upgrade it.
As a result, consumers are likely to see steep increases in their sewer bills. How steep? A typical $25 monthly bill could go up to $100 within the next 10 years, said Jeff Theerman, executive director of MSD. The money would go into a capital improvement program to bring St. Louis in line with federal standards. The biggest priority is reducing the amount of sewage that enters our rivers.
MSD by the numbers
MSD operates and maintains 9,649 miles of sewers in St. Louis city and St. Louis County. It covers all of St. Louis city and eight-tenths of St. Louis County; the westernmost portion of St. Louis County is covered by a patchwork of smaller sewer districts.
Within this network, about 50 percent of the sewers solely carry wastewater away from people’s homes; 30 percent carry stormwater only; but, most problematically, the remaining 20 percent handle a combination of wastewater and stormwater.
The sewer system contains hundreds of relief points, where a combination of stormwater and untreated sewage is fed into waterways, causing pollution that has been the subject of an Environmental Protection Agency lawsuit. The lawsuit is currently in mediation. Although the idea of these relief points may be unpleasant, without them the community would experience more basement backups and more on-street flooding.
“If we were going to build a new system this isn’t how we’d do it — but that’s the system we’ve got,” said MSD spokesman Lance LeComb.
“Though most overflows predate the district creation in 1954, they are still MSD’s responsibility and efforts to address the problem must continue,” argues a fact sheet distributed at a recent set of open house meetings about the issue.
When these overflows occur is somewhat predictable — immediately after moderate to heavy rainfall; but almost as important as the volume of rain is how quickly it comes down. Theerman said MSD is not in a position to eliminate these overflows, but it can aim to cut down how often it happens from, say, 50 times a year to between six and 12 times a year.
River Des Peres
Of the various rivers and creeks in MSD’s service area, River Des Peres has, by far, the greatest problem with pollution.
What was once a natural river is now, for the most part, a concrete channel that is part river, part sewer. Rain rolling down rooftops and hillsides in the area finds its way into the channel, but during heavy rain, it is accompanied by sewage from local homes and businesses.
Having been buried for decades, the Forest Park portion of River Des Peres has been brought back above ground in recent years. But that’s only a small part of the river’s course. Almost everywhere else, due to decisions taken in the early 20th century, River Des Peres has a concrete river bed; in some places it’s open to the elements and elsewhere it becomes a tunnel that disappears underground.
Theerman said the river’s look can be improved. It doesn’t have to remain as an “industrial channel” and MSD has been working with Great Rivers Greenways to create linear parks that run alongside River Des Peres. But improving River Des Peres’ aesthetics will be an arduous process and people should not be deluded into thinking that River Des Peres will ever be a “babbling stream,” he said.
The portion of River Des Peres that runs alongside the Macklind Pump Station, near the intersection of Manchester and Macklind avenues, is the largest of MSD’s combined sewer overflows — the points at which sewage is deliberately let into the waterway. Over the course of a year the channel carries 3,507 million gallons of water and can be expected to carry sewage (in addition to stormwater) 44 times a year.
The water flows on to a treatment plant in the Lemay area, one of seven MSD treatment plants.
The actual amount that flows through the sewers at Macklind varies greatly week to week and month to month.
Last September water gushed through these tunnels, Theerman said. It was as full as anyone at MSD could remember and River Des Peres carried water equivalent to one-sixth of the Mississippi’s flow, Theerman said. Yet on a recent spring day when Theerman led a tour of the sewer, it was almost empty: a few inches deep in most places, perhaps a foot in the deepest parts.
Carved above the entryway to the tunnels it says: 1928 DES PERES DRAINAGE WORKS, in the proud lettering of an era of ambitious public works.
As the water goes from daylight to darkness, above ground to underground, it flows into one of three tunnels: there are two 30-foot tunnels and a smaller 16-footer, all running in parallel. Between the tunnels there is the occasional hole that allows water to flow from one tunnel to the other. Without this feature, the water could build up in one tunnel and exert an undue amount of pressure on the walls.
Despite the fact the sewer is more than 80 years old, it’s in good physical shape, Theerman said, as he shone his flashlight into the darkness. More than once, with the flashlight weakly illuminating the tunnel’s roof 30 feet above him, Theerman spotted a patch of concrete with exposed rebar — the metal supports that give a tunnel its strength. It’s the kind of problem that doesn’t need dealing with immediately but it does require repair, he explained.
Multi-billion dollar price tag
Patching concrete is a small problem compared to others on MSD’s plate.
To entirely separate the wastewater and stormwater systems would cost $18 billion. That’s just not realistic, Theerman said. Instead MSD is planning a series of projects that could cost between $4 billion and $6 billion. A plan must be submitted to federal regulators by October, and only after that will the list of projects be finalized. The size of investment remains vague because of two key factors, LeComb said. The first is public tolerance of bill increases, which must be approved by the Rate Commission, and the second is the mandates that the federal regulators put on MSD, he said.
The sewer district has already made significant investments to attack the problem of sewer overflows, LeComb said.
Since 1992, MSD has spent more than $600 million to reduce the need for sewer overflow points, principally by increasing capacity at treatment plants and building express sewers to get water to the plants more quickly. However, there are still 200 overflow points in the system.
Another option is to build storage facilities to hold stormwater during rainfall. Additionally, MSD wants the public to help slow the runoff into stormwater sewers by using rain barrels and by replacing impermeable surfaces, such as concrete, with green space.
St. Louis’ aging sewer infrastructure is “certainly not unique,” LeComb said. “Atlanta, Boston, L.A., Portland, Louisville, Indianapolis are at some stage of dealing with the problem.”
What makes St. Louis unusual though is the size of its sewage infrastructure — it is the fourth largest in the country in terms of miles of pipes, about the same size as Los Angeles’. But the St. Louis population is a third of that of L.A.’s, so “there are fewer people to share the maintenance and rehabilitation costs,” LeComb said. That means that fully fixing the problem would put an unreasonable burden on ratepayers, he said.
In other communities where the federal government and sewer districts have clashed, plans with a 20-year timeframe have been agreed upon. But given St. Louis’ specific problems, 20 years is “not realistic,” LeComb argued. MSD is looking at a variety of possible engineering projects, but people need to remember that “how quickly that work is done impacts the sewer bill,” he said. Consumers, about to face an increase in sewer bills from $25 to $100 over 10 years, are unlikely to be willing to pay more over and above that, LeComb said.
Whatever solution is agreed upon — which set of solutions, over what timeline — “it is going to be an economic stress on the community,” Theerman said.
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