September 14, 2005 - By MIKE ANTHONY
|This photograph was taken from 200 feet below ground level where aeriation tanks meet with the tunnel under the Meramec River.|
|This photograph shows the inside of the tunnel, which, when completed, will be nearly four miles long and will carry wastewater from the Baumgartner Lagoon to the new treatment plant.|
|Shown are some of the pipes in the treatment plant. The day the Call visited, the pipes had just been painted.|
The Metropolitan St. Louis Sewer District's Lower Meramec Treatment Plant is expected to be operational by the fall of 2006, according to Brian Hoelscher, MSD director of engineering.
The Lower Meramec Wastewater Treatment Plant, which is being constructed near Rogers Elementary School, will clean wastewater before discharging it into the Mississippi River. It will replace the Meramec and Baumgartner lagoons and eventually the Grand Glaize and Fenton treatment plants.
The district is under an administrative order from the Missouri Department of Natural Resources to eliminate the Baumgartner Lagoon by December 2006 or pay up to $10,000 per day in penalties.
The Meramec and Baumgartner lagoons will remain operational until the new plant is ready. A nearly four-mile-long tunnel that will carry wastewater from the Baumgartner Lagoon to the new treatment plant is being constructed roughly 200 feet underground.
The concept of a regional treatment plant dates back to the late 1970s, Hoelscher told the Call.
"There's two beginnings for this program. Back in the late '70s when the district annexed the area around the Meramec River, there was a plan put into place to treat raw sewage that was entering the Meramec River,'' he explained. "So two things happened. One, we built all the interim facilities that exist now and the main ones are the Meramec lagoon that's right out here near the plant, the Baumgartner lagoon, which is the upstream end of this project and then we've got a plant in Fenton and the Grand Glaize plant in Valley Park.
"Those four facilities were built as interim facilities. The idea in the late '70s was you put those in now to treat sewage immediately. Eventually you will build a regional plant at this location ...,'' he said, adding that the regional plant would treat wastewater for the entire watershed.
Problems at the Baumgartner Lagoon — capacity issues, odor problems and an occasional discharge issue — accelerated plans for the regional treatment plan, Hoelscher said.
Referring to the DNR's administrative order, Hoelscher said, "That's what's driving the first phase of this program. That's why we're doing it now and doing it to the size we're doing it. When that issue came up, the district considered two options. One was a smaller version of putting just enough treatment facility and piping just to take the Baumgartner Lagoon off line or starting what ultimately would be a regional plant and putting that facility in. (In) discussions with DNR, they indicated you need to head toward the ultimate solution, which was the eventual development of a regional plant.
"And that's why in this plant, in the tunnel, the size of the well for the pump station, they're sized to eventually process four times as much wastewater than they will initially because we want to size them to be able to treat eventually the entire watershed,'' he added.
The treatment plant that's being constructed initially will process roughly 15 million gallons per day of wastewater, but includes provisions to eventually allow it to expand to treating 60 million gallons per day.
"Right now this plant's being built for about a quarter of its full capacity. Fenton would account for another quarter and Grand Glaize would account for half of its ultimate capacity,'' Hoelscher explained.
Construction of the Lower Meramec Wastewater Treatment Plant began in the fall of 2003 on the 200-acre site near Rogers Elementary School.
"This plant's about 75 percent complete right now and ready to start dry start-up, which is checking the electrical connections and making sure all the motors work, some time in the coming spring or summer of 2006. That's when it will be ready to go,'' Hoelscher said.
The nearly four-mile-long tunnel is about halfway complete, he said, noting that the tunnel will go underneath the Meramec River into Jefferson County and then return underneath the river to St. Louis County. Shaft work totaling $1.75 million will allow the city of Arnold to pump wastewater to the tunnel and the treatment plant. The MSD will pay the construction costs and bill Arnold over a 20-year period for the work.
At the treatment plant the tunnel will discharge into a lift station where large pumps will lift the water up to above the surface to begin the flow through the plant's treatment process.
"All of this process, there are parts of it that will be ready to go in spring 2006, but because of some delays the tunneling contractor experienced and because we have to have the tunnel done to get flows to the plant, we're looking at start-up now being completed fall or winter of 2006,'' Hoelscher said. "November's the date that shows up on the schedule.''
He later added, "Originally we were looking at start-up starting around spring 2006. We're now looking at fall 2006 is when we start up the plant. There'll be the wet start-up. There'll be various pieces we'll test, but actually be running flows through the plant will probably happen in the fall of 2006.
"Right now this is a $223 million program. We've got under contract $215 million ... There's only $8 million left. That's things like demobilizing the site. We've got an educational/recreational facility (to be built). Things that aren't in the administrative order ... Ninety-five percent of this program right now is under contract and is progressing.''
That $223 million encompasses all aspects of the project, including the treatment plant, the tunnel, lift station, site work and electrical supply to the site. It also encompasses future projects, including a wetlands mitigation project and an educational/recreational facility.
MSD voters last year approved a bond issue that will help fund $3.7 billion worth of sewer system improvements over the next 18 years. The first phase of improvements will cost $647 million, including the Lower Meramec Wastewater Treatment Plant, over a three-year period.
Voters agreed in February 2004 to pay $500 million of that through the bond issue. Those funds are exclusively reserved for the first phase of the project. The additional $147 million will be paid through a rate increase that was effective last year.