MSD Fenton Wastewater Treatment Plant Update: Secondary Treatment Operations Restarted & Community Update Meeting Scheduled

Work continues on restoring full treatment at the Metropolitan St. Louis Sewer District’s (MSD) Fenton Wastewater Treatment Plant (WWTP) in Fenton, Missouri.  Regular testing of the Meramec River by MSD also continues.   The latest results can be found here.Meramec Water Quality Report 3-16-16

In the test results, you will find a green colored number next to the numbers we reported for testing.  This is testing that the Missouri Department of Natural Resources (MDNR) is conducting as well.  While there is a difference in the MDNR and MSD numbers, it is normal to have this type of variance.

The most recent MSD testing, conducted on March 16, 2016, shows increases and decreases in E. Coli levels, both upstream and downstream of the Fenton WWTP.  As stated in previous updates, volume of river flow, the amount of direct sunlight on the river, has it rained or snowed recently, and other factors all impact bacterial degradation and water quality results.  Accordingly, test results will fluctuate – sometimes dramatically – in one direction or the other, from week to week.  To date, we have not observed indications of a fish kill or stress to other aquatic life in the Meramec River.

Missouri American Water is also conducting independent testing of their drinking water.  Results of this testing can be found at  Once at the homepage, find the “Water Quality Reports” header in the upper right corner.  Underneath this header is a link titled, “Drinking Water Quality Update:  South St. Louis and Jefferson Counties.”

As of March 13, 2016, MSD contractors have worked over 15,000 hours to restore operations at the plant.  Much of the work has been related to electrical systems at the plant.  Thus far – and as an example of the extensive nature of the repairs that are needed – approximately 73,000 feet (or approximately 14 miles) of electrical wiring has been replaced.

Wastewater continues to go through the primary treatment process on temporary generator power.  (Primary treatment is the stage at which solids are removed from the wastewater stream.)  Workers are on site around-the-clock to operate and maintain equipment and generators.

Secondary treatment – the step in treatment that uses “good bacteria” to “eat bad bacteria” – has been restarted.  Accordingly, monitoring of effluent quality has begun.  Results will be reported in the next update. 

All of the major disinfection/ultraviolet light equipment and controls are back at the plant.  Crews are working as quickly as possible to rewire and reinstall the equipment.  (Disinfection is the third step in the wastewater treatment process from April 1 through October 31.) 

Based on the current assessment of the damage and time needed for repairs, it is estimated that full treatment will be brought back on-line in April.  Other repairs to ensure backup systems and restore other non-critical functions of the plant will take longer.

MSD will host a community update meeting on Friday, April 8, 2016, at 6:00pm.  The meeting will take place at the City Hall for the City of Arnold, located at 2101 Jeffco Boulevard, Arnold, MO 63010.  (Please use the rear entrance.  Signage will also be posted to the direct the public to the meeting room.)  Representatives from MSD will be on hand to report on progress to date in restoring operations at the Fenton WWTP and to answer any questions from the public.

While there is no immediate threat to the public’s health or safety, the public is still advised to avoid contact with the Meramec River from Fenton, Missouri, to the Mississippi River.  Signs have been posted in areas where the public may readily come into contact with this section of the river.  If anyone should come into contact with the river in this area, it is recommended they immediately and thoroughly wash with soap and water.

MSD will continue weekly water quality monitoring of the Meramec River near the Fenton WWTP.  

Until the full treatment process is restored at the Fenton WWTP, MSD will make regular updates available on its website,

For previous updates and other information on the impacts of the December 2015 rains and floods on MSD operations and the Fenton WWTP, please visit

For weekly videos of ongoing work at Fenton WWTP, please visit