Portfolio Categories: Wastewater
Fountain City Road Sewer Relocation
City of De Soto
Cochran designed 800 lineal feet of 18” gravity sewer for the City of De Soto. The sewer relocation was a result of new development within the City. The project included several challenges including grade restrictions, crossing Joachim Creek, and a directional bore under Fountain City Road. Cochran’s scope of services included surveying, easement documents, design, permitting with the Corps of Engineers, coordination with the railroad, bid administration, construction administration, and inspection. The new sewer was placed in service in March of 2017.
Campbell City Gravity Sewer Extension
City of Ozark
Cochran designed 1,800 lineal feet of 8-inch gravity sewer for the City of Ozark. The project provided public sewer to an un-serviced region of the City and allowed multiple private sewage holding tanks and septics to be eliminated. In addition to the environmental benefits of the project, the extension provides public sewer to undeveloped property which previously had no sewer available. Cochran provided all aspects of design including surveying, easement documents, design, permitting, bid administration, construction administration, and inspection. Construction of the project was completed in 2018.
ECM Sanford Creek Lift Station
East Central Missouri Water & Sewer Authority
Cochran designed a new lift station that serves the entire East Central Missouri Water & Sewer Authority. The lift station was constructed to redirect sewage from the City of St. Charles to St. Peters for treatment. The lift station design included two 890 gpm 60 horsepower pumps, 13,500 feet of 10″ force main, underground concrete emergency storage basin, permitting with the Lakeside 370 Levee District, and permitting with MoDOT to cross Hwy 370. The project had a list of challenges which included a creek crossing, aerial crossing over railroad tracks, levee crossing and maintaining a maximum allowable flow to the existing St. Peter’s lift station. To accomplish the flow rate requirements, VFD’s were used to control the pump rate and emergency underground storage size to hold excess flow. The lift station was placed in service in 2016.
MBR Treatment Plant
St. Charles County PWSD No. 2
Cochran provided survey and civil design services for St. Charles County PWSD #1. We performed the study and design of a complete 0.25 MGD membrane bioreactor (MBR) wastewater treatment facility, which will be expandable to 1.0 MGD. The project also required installation of approximately 4.75 miles of 8 to 12-inch diameter sewer main for a 380 lot subdivision. The lift station is sized to serve 112 lots and 1 elementary school. Cochran also completed a receiving stream impact study. We designed for future ultraviolet disinfection at a peak flow rate of 4 mgd. Cochran also designed mechanical, electrical and structural aspects. The facility utilizes flat-panel membrane technology to meet effluent design limits of 10 mg/L BOD and 15 mg/L TSS. The facility design includes a laboratory to perform required self-monitoring analytical work and process control tests for all treatment processes.
Denmark Road Treatment Plant
City of Union
This is an on-going project for the City of Union which includes the expansion of an existing 300,000 gpd oxidation ditch. Work includes: antidegradation review, new headworks, new sludge digestion facility, new 500,000 gpd Schreiber Counter Current Aeration and conversion of gaseous chlorinated disinfection system to UV disinfection. The City of Union traditionally used chlorine gas for wastewater effluent disinfection. For safety and economic reasons, the City is discontinuing the use of chlorine gas. In addition, a new 950 gpm lift station was installed to provide for future expansion. Cochran aided in the procurement of funding for this project along with design, permitting, construction inspection and construction administration.
Aeration System Upgrades
The City of St. Clair
Cochran designed improvements to the aeration system of the City’s 1.1 MGD plant. The improvements were implemented to provide more efficient and effective treatment. Improvements included operating the aeration system with variable frequency drives to allow the operator increased control of dissolved oxygen levels. The newly installed variable frequency drives and dissolved oxygen probes allow the aeration system to operate at the proper speed to maintain optimum dissolved oxygen levels. The aeration system improvements were completed in 2017. Cochran provided all aspects of the following services: funding agency loan assistance, energy analysis, design, permitting, construction inspection and construction administration.