A new sewage-treatment plant in Oakville that was supposed to be operational by Dec. 31 now should be on-line in early February.

Metropolitan St. Louis Sewer District Public Affairs Specialist Lance LeComb said Monday afternoon the Missouri Department of Natural Resources has agreed to a 90-day extension of the deadline for the Lower Meramec Wastewater Treatment Plant’s date of operation.

LeComb said although the sewer district now has until March 31 to have the new plant operational, he anticipates it should be up and running in roughly four to six weeks.

MDNR and MSD officials also have agreed to a 90-day extension to eliminate the Baumgartner Lagoon, which was supposed to be closed by Dec. 31. MDNR previously had ordered the sewer district to meet the deadline or pay up to $10,000 per day in penalties. The district also has been granted a one-year extension for the Meramec Lagoon.

The Lower Meramec Wastewater Treatment Plant 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.

District officials have cited a three-month delay in the construction of a nearly four-mile tunnel being constructed 200 feet underground as the main reason for the 90-day extension request for the plant’s operation. Porous rock in the tunnel caused it to leak, and MSD officials said such a leak would pose a danger to any workers. The tunnel will carry wastewater from the Baumgartner Lagoon to the new treatment plant.

Construction of the Lower Meramec Wastewater Treatment Plant began in the fall of 2003 on a 200-acre site near Rogers Elementary School. The project includes four components — the treatment plant, a lift station, the tunnel and a sanitary trunk sewer that will take the existing Baumgartner pump station off-line and send wastewater into the tunnel.

MSD Director of Engineering Brian Hoelscher has estimated that those four components total roughly $175 million of the $230 million Lower Meramec Wastewater Treatment Plant program.

In December, the district’s Board of Trustees transferred $500,000 from the treatment-plant budget to the lift-station budget. MSD officials have said the transfer was necessary because the cost for delays in the lift-station project budgeted in the January 2006 appropriation were $750,000 higher than projected. Hoelscher has said the treatment plant was completed roughly $1.7 million under budget and the $500,000 will come from that balance.

While working to finish the Oakville treatment plant, MSD officials also are responding to increased federal and state regulations by considering the possibility of raising rates for wastewater and stormwater service.

The MSD Board of Trustees was scheduled at 5 p.m. today — Jan. 11 — to consider sending those proposed rate hikes to the MSD Rate Commission. The earliest the rate raises could go into effect would be in January 2008.

LeComb and other MSD officials have reiterated that the proposed rate hikes have nothing to do with the Lower Meramec Wastewater Treatment Plant and that the program cost for that plant will remain at roughly $230 million.

With respect to the proposed rate increases, the Rate Commission would have 165 days to consider the rate proposals and schedule “in the neighborhood” of six public hearings.

As proposed, the average MSD customer would go from paying $22.38 per month for sewer service to $36.79 per month by the district’s 2012 fiscal year, which begins on July 1, 2011. That wastewater-service raise would total a 64-percent increase in rates spread across incremental increases from 2008 to 2012.

Rates for MSD’s wastewater service would climb by 15 percent in 2008, 12.2 percent in 2009, 10.9 percent in 2010, 9.1 percent in 2011 and 5.2 percent in 2012.

Stormwater service would also go from being a flat fee of 24 cents per month to a system based on the amount of impervious — or non-absorbent— property on an owner’s lot. Impervious property includes non-absorbent property like driveways, roofs, garages and parking lots.

The proposal calls for the district to begin charging 12 cents for each 100 square feet of impervious property and then gradually raise that level in increments to 19 cents per 100 square feet of non-absorbent land by July 1, 2011.

The average customer then would pay $4.76 per month for stormwater service, according to MSD officials.

LeComb said if the stormwater measure is approved by the Board of Trustees, MSD then would cut two current property taxes totaling seven cents per $100 of assessed valuation that go toward stormwater projects.

Besides the proposed rate increases, the Board of Trustees also will consider dividing its area serving 1.4 million customers into five separate subdistricts split by major watersheds. Each subdistrict could levy its own property taxes with elections for what LeComb has said would be “enhanced” stormwater service.

LeComb also added that the rate increases for wastewater service would be more beneficial to the district to prevent financing any future projects with additional bonds and instead use a running bank for costs. Such an approach would save roughly $400 million in interest costs, according to MSD officials.

Those costs for wastewater regulatory improvements would include projects like increasing wet-weather capacity at plants, better understanding system defects, reducing extraneous water entering sewers from inappropriate connections, reducing combined sewer overflow events and eliminating constructed overflows in a separate system.

To discuss the proposed rate hikes and ongoing projects, roughly 15 to 20 MSD officials will be at the Westfield Shoppingtown Crestwood from 5 to 8 p.m. Jan. 25 to answer questions from the public.

“We’re trying to be as sensitive as possible to the pocketbooks and the household budgets of our rate payers,” LeComb said. “They’re families and they’re individuals, and we understand that. At the same time, there are a host of regulatory-driven needs that we have to address and we have to pay for. So we’re working to really identify the best balance between the two. By no means is our opinion the only opinion. There will be extensive public outreach through the Rate Commission process. But we believe this is the right action to take for our community. And in the long run, it really puts us in the best position to ensure that we have a clean environment, to ensure that we’re reducing overflow in area rivers and streams and to ensure that we’re properly managing stormwater.”