WATER RESOURCES

Engineering a Stronger Community: Extending the life of sewage treatment plants by reducing the amount of rainwater directed toward them

For this project, CDI investigated and made recommendations for the disconnection of private inflow and infiltration (I/I) sources into the public sanitary sewer. The project area comprised six study areas from the Metropolitan St. Louis Sewer Districts (MSD) Combined Area I/I Evaluation. Most homes in the project area were constructed between 1940 and 1960 using vitrified clay pipe sewers and private laterals.
The Preliminary Plan identified approximately 2,500 individual properties in the project area and anticipated that 200 of these properties would have a stormwater drain connected to the sanitary sewer. Upon investigation, CDI discovered approximately 1,600 properties with suspect private drains.

Client/Owner: Metropolitan St. Louis Sewer District
Year: 2011
Cost: $1,600,000

Engineering a Stronger Community: Reducing flooded basements and keeping untreated sewage from entering our streams

The purpose of this project was to alleviate wet weather sanitary sewer overflows and basement backups. The project solution was a combination of private inflow and infiltration removal and the construction of a new sanitary relief sewer. CDI delivered a Private Inflow Reduction Report (PIRR) for approximately 22 homes to facilitate separation of private inflow from the sanitary system. CDI also modeled the existing and proposed sanitary sewer systems using HYDRA to assess sewer capacity, and evaluate inflow and infiltration.

Client/Owner: Metropolitan St. Louis Sewer District
Year: 2010
Cost: $431,000

Engineering a Stronger Community: Reducing operating costs for the local sewer district while also reducing untreated sewage discharges into streams

The purpose of this project was to eliminate two pump stations by construction gravity outfall sewers to connect to the existing sewer system completed as part of Phase I. CDI designed approximately 3,800 linear feet of 8 to 10-inch sanitary sewer and appurtenances to eliminate the two pump stations, and reduce the occurrence of sanitary sewer overflows. CDI also delivered a PIRR that involved four home inspections. CDI modeled the existing and proposed sanitary sewer system using HYDRA software to assess sewer capacity, evaluate system inflow and infiltration, and assess the removal of the sanitary sewer overflow.

Owner/Client: Metropolitan St. Louis Sewer District
Year: 2009
Cost: $1,400,000

Engineering a Stronger Community: Reducing flooding and erosion problems in lawns along several neighborhood streets

This project consisted of four storm water projects all intended to address local flooding, drainage or erosion issues. All projects included construction of an underground storm sewer to intercept and convey storm water from a drainage area adjacent to the respective homes and neighborhoods.

Client/Owner: City of Maryland Heights
Year: 2011 - 2012
Length: 1800 feet
Cost: $533,000

Engineering a Stronger Community: Finding a solution for an overloaded sewer line that provides much-needed storm relief

The purpose of this study was to develop the preliminary design and cost estimate to rehabilitate or replace the existing foulwater interceptor (FWI) sewers located below the River Des Peres storm channel due to excessive inflow and sewer pressure. Civil Design, Inc. provided field coordination to locate and inspect manhole structures along the River Des Peres storm channel within the project area. CDI also evaluated alternatives to removing and replacing the existing FWI sewers with one new sewer.

Client: Horner & Shifrin
Owner: Metropolitan St. Louis Sewer District
Year: 2009
Length: 220 feet
Cost: $3,300,000

Engineering a Stronger Community: Providing new storm sewers to relieve flooding and reducing the amount of flow towards sewage treatment plants

This project consisted of two separate storm water projects in the Coldwater Creek Watershed.

• Goodale and Verona Storm Sewer Improvements: CDI designed 1,700 feet of new 12 to 42-inch storm sewer. This included a 404 Nationwide Permit from the Corp of Engineers.
• Midland & Angelo Storm Sewer Improvements: CDI designed 2,255 feet of new 12 to 36-inch storm sewer and recommended the installation of flood proofing at four homes.

Client/Owner: Metropolitan St. Louis Sewer District
Year: 2008
Length: 4,000 feet
Cost: $1,550,000

Engineering a Stronger Community: Addressing homeowner issues relating to sewer and storm drainage problems that are affecting their properties

Civil Design, Inc. is working with Jacobs Engineering on a multi-year planning effort underway with the Metropolitan St. Louis Sewer District. The goal of the Watershed project is to assess watershed regulatory and customer service issues and develop appropriate projects/solutions to these issues based on all the interrelated systems.
CDI has performed many functions with a full-time engineer assigned to the Jacobs office. CDI has also supported the District’s ongoing hydraulic modeling effort with an engineer staffed at the District Hydra Modeling building. Throughout the project, CDI engineers have used a variety of existing data including I/I reports, reviewing hours of CCTV footage, analyzing flow meter data, reviewing existing MSD complaint record and insurance receipts, and modeling and reviewing model results.

Client: Metropolitan St. Louis Sewer District
Year: 2007-2013
Cost: $51,800,000

Engineering a Stronger Community: Finding and eliminating storm connections to the sewage system so that treatment plants are not overloaded

The purpose of this project was to identify sources of inflow and infiltration (I/I) in the separate sewer system and propose rehabilitation methods that will reduce or eliminate sanitary sewer overflows and achieve an overall 25% reduction in I/I. The team conducted smoke testing, manhole inspection, CCTV, dye flood testing, and computer modeling. Following this field investigation, flow meter data and defect data analysis was conducted and reports generated and modeled using Hydra sanitary hydraulic software; rehabilitation recommendations were subsequently made.

Client: Metropolitan St. Louis Sewer District
Year: 2004