Water & Wastewater Engineering

Lake Charles B/C WWTP

The new WWTP B/C in Lake Charles, LA will replace the existing WWTP B/C and have a rated capacity of 9 MGD with a peak flow of 35 MGD. The contractor for the new $42 million plant started construction in April 2016 and is scheduled to be complete by April 2018, a few months ahead of the original schedule. The new plant consists of:

  • 35 MGD influent pump station with 5 vertical turbine solids handling VTSH pumps and two mechanical bar screens
  • Headworks complete with fine screening, grit removal and two flow splitter boxes - one for raw wastewater and one for return activated sludge
  • Two multi-channel oxidation ditches with rotary disc diffusers
  • Three final clarifiers
  • Ultraviolet disinfection facility with an NPW system
  • Sludge drying bed
  • Return activated and waste activated pump station
  • Two new electrical switch gear buildings
  • Miscellaneous civil, electrical, instrumentation, etc.


“Construction Progress - September 2016”

Construction Progress – September 2016


“Construction Progress - September 2016”

Construction Progress – September 2016


Lake Charles WWTP Project - June 2016

Construction Progress – June 2016


Lake Charles WWTP Project - March 2016

Construction Progress - May 2016


Red River Wastewater Treatment Plant Upgrade and Expansion

Construction is complete on this $60 million project. This new WWTP was designed by Manchac Consulting Group, Inc.  to replace the existing Red River WWTP. The new Red River WWTP has a rated capacity of 12 MGD with a peak flow capacity of 48 MGD. The plant has been up and running since December of 2014.


The new plant consists of:

  • 48 MGD Influent Pump Station with two mechanical bar screens and a septage receiving station; the Pump Station will have five (5) Vertical Turbine Solids (VTSH) pumps
  • Headworks complete with Fine Screening, Grit Removal, Odor Control, and two Flow Splitter Boxes – one for raw wastewater and one for return activated sludge
  • two multi-channel Oxidation Ditches with Rotary Disc Diffusers
  • three Final Clarifiers
  • Ultraviolet (UV) Disinfection System with an NPW System
  • Final Effluent Pump Station with six (6) Axial Flow Pumps
  • new Outfall Line and Headwall Structure
  • new Belt Filter Press Building
  • new Lab/Administration Building
  • Sludge Drying Beds
  • upgrade to the Class A Sludge Treatment Facility

The work at the NE WWTP consists of:

  • Replacement of old mechanical equipment
  • Installation and design of new SCADA system
  • Installation of a new Influent Sewer Main
  • Heavy civil/site work to repair embankment along Red Chute Bayou

Manchac was authorized to begin the design of this project in April of 2011, with 480 calendars to fully complete the design and be ready to advertise-for-bids. The design was completed in April of 2012, and we received bids in June of 2012. The NTP was given to the contractor in August of 2012. Manchac’s construction cost estimate for the project was $67 million, and the low bidder was $60 million. In addition to the bid being $7 million lower than our estimate, we worked with the contractor and came up with over $1 million in Value Engineering items that the owner accepted. This state-of-the-art facility will serve the citizens of Bossier City for many years to come.

Water Distribution System Water Main Replacement

The City of Bossier City was experiencing failure of a major water transmission main that ran north-south through the heart of the City. The existing 20” reinforced concrete cylinder pipe ruptured numerous times and cost the City over $500K to repair over a two-year period.   The City declared an emergency in accordance with Public Bid Laws in order to get the old pipeline replaced in an expeditious manner to avoid a situation of not being able to provide water to a large segment of the city. Manchac was hired in March of 2012 to design the replacement for the pipe and immediately had the route surveyed so plan and profile sheets could be developed. This project was complicated by the mere nature of the pipeline easement being only 10 feet wide. Just to the south of the easement lies the Louisiana-Arkansas railroad, and just to the north of the easement lie wetlands, private property, and businesses. To make matters more complex, the new pipeline had to cross a 20-foot deep by 100-foot wide canal.

It was quickly determined that horizontal directional drilling (HDD) techniques would have to be used to avoid the disturbance of private property and negating the need for the City to acquire ROW. Manchac designed over 11,000 feet of pipe using 36” Ductile Iron Pipe (Class 150) for the open-cut portions (about 8,000 feet) and 36” HDPE pipe (about 3,000 feet) for the HDD portions.

This entire project (beginning with the Notice To Proceed from the City, through design, construction, and closeout) was completed in three months. The project was broken into phases – one for the open cut portion and another for the HDD portion. Design work on the open cut portion was completed in two weeks and let to bidders with bids received in five days under the emergency provisions. The design work on the HDD portion was completed in three weeks and let to bidders, with bids received in seven days. All of the work was substantially complete by the end of June 2012.  Numerous regulatory agencies were involved in the project, including the US Army Corps of Engineers for reasons of obtaining permission to clear vegetation in wetland areas. All approvals were obtained and mitigation strategies approved prior to letting the projects to the contractors.


Manchac’s original construction cost-estimate on this project was $10 million due to the fact that we feared HDD would have to be used for the majority of the route. We quickly got to work along with City personnel and obtained right-of-entry agreements from over 20 property owners, negating the need to use HDD. This saved the City $5 million.

Wastewater Treatment Plant ‘A’ - Phase I Improvements

In 2010 the City of Lake Charles contracted with Manchac Consulting Group for the design of improvements to WWTP ‘A,’ as part of Phase I of the improvements to the City’s wastewater system.  Construction began in the summer of 2011 and was funded by the Louisiana Department of Environmental Quality’s State Revolving Fund.

Scope of Services for Phase I included:

  • Planning, Design, Bidding,  Construction Management and Resident Inspection
  • Remove existing grit removal system, and replace with new aerated grit removal system.
  • Remove existing chain and scraper mechanism from each of the existing nine primary clarifiers, and replace with new chain and scraper mechanism.
  • Install new electrically actuated telescoping valves on each of the nine existing influent pipelines at the existing primary sludge pit and on each of the six existing influent pipelines at the new final sludge pit.
  • Remove the three existing primary and three existing final sludge pumps, and replace with three new submersible primary and two new submersible final sludge pumps, each VFD controlled.
  • Remove existing air diffusers in each of the three aerobic digesters, and replace with new air diffusers in each of the three aerobic digesters.
  • Remove replace the plant’s main utility transformer and other miscellaneous electrical equipment.

Construction was completed during the summer of 2012.

Total Construction Costs $3,747,000


City of Lake Charles, LA


Aster Street Waterline Extension

The City of Lake Charles contracted with Manchac Consulting Group in the fall of 2010 to provide design services for this project.

Work included installing a new waterline on Aster which will connect to the existing parallel waterline on E. Prien Lake Road and Craft Street.  Construction was completed in early 2011 and included:  880 linear feet of 8-inch HDPE installed by directional drilling, 70 linear feet of 8-inch HPDE installed via open cut, eighteen new 1-inch service connections, and four new 2-inch service connections were tapped into the new waterline.

Penn Street and 12th Street Lift Station Rehabilitation Projects

Manchac Consulting Group was retained by the City of Lake Charles to design to upgrade and rehabilitation of its Penn Street and 12th Street Lift Stations.  This project will ultimately address the existing deficiencies in the Lift Station’s pumping operations.  These lift stations are currently not keeping up with in coming flows due to the poor performance of the outdated, existing pumps.  As part of this project, all pumps, valves and appurtenances shall be upgraded to provide more efficient performance. Also, all motor controls will be moved above grade to protect them in the event of flooding.  This project will replace at each station the three existing centrifugal pumps and respective vertically shafted motors with three new dry pit submersible pumps.  The below grade electrical/controls at each station will be relocated and replaced with new electrical/controls in a free standing control panel located on the exterior concrete slab of the stations above the 100-year flood elevation level.


CDBG Disaster Recovery Emergency Generator Design

Manchac Consulting Group was retained by the City of Lake Charles to design emergency generators for the City’s George West Water Treatment Plant, and Wastewater Treatment Plants ‘A’ and ‘BC’.  The three generators will provide backup power generation for the operation of each facility in the event the primary power feeds are lost.

Sale Road Waterline Replacement

As part of the Sale Road widening project in Lake Charles, Manchac was retained to relocate a 12” water main. This project included a 2,000 foot directional drill to go under a bayou and avoid wetlands.


Budweiser Lift Station Rehabilitation

The scope of work includes the following:

  • Remove existing pumps and replace with submersible pumps
  • Remove existing piping and valves and replace with new
  • Remove existing electrical and controls and replace and relocate with new
  • Clean, repair, and coat the wet wells.


Lake Charles, LA

United States

See map: Google Maps

Project Image:


Fox Run Lift Station Rehabilitation

The scope of work includes the following:

  • Remove existing pumps and replace with submersible pumps
  • Remove existing piping and valves and replace with new
  • Remove existing electrical and controls and replace and relocate with new
  • Clean, repair, and coat the wet wells.


Lake Charles, LA

United States

See map: Google Maps


Riverside Park Water and Sewer

Manchac Consulting Group worked as a subconsultant, designing a wastewater pump station and forcemain to serve a new park development.  Design services also include a new pedestrian / golf cart path, a water line extension and a new boat launch for the park.

Manchac Consulting Group’s Scope of Work included design services for:

  • A 6-foot wide, approximately 3,500-foot long concrete path for an entryway to the park from the boat launch off Fitzenreiter Road on the Calcasieu River.
  • A 3,100 linear foot 4-inch waterline and a 1,280 linear foot 6-inch waterline to provide potable water to the park
  • A duplex sewer lift station and 4,480 linear foot 3-inch sewer force main to tie into an existing sewer manhole


Don and Riverview Lift Stations

Manchac Consulting Group, Inc. was hired by Bossier City to provide engineering services related to the upgrade of their Don and Riverview Lift Stations. These two lift stations are two of the major sewer lift stations in Bossier City, and their reliable operation is critical. The Don Lift Station is located in the parking lot of Pierre Bossier Mall, and the Riverview Lift Station is located near Diamond Jack’s Casino. Reliability of the existing pumping equipment at both pump stations is no longer dependable, and much of the ancillary equipment, including flow meters and variable speed drives, is no longer in use.

Manchac’s scope of work includes selection of replacement pumps, mechanical design, electrical and instrumentation design, structural design, civil/site design, resident inspection and general engineering services during construction. This project consists of dry pit submersible pump design, dry pit ventilation improvement, electrical upgrades and wet well coating.

Construction Cost: $2,000,000


Bossier City, LA

United States

See map: Google Maps

Project image:



City of Bossier City - State Revolving Fund Loans - 201 Facility Plan Updates

The engineers at Manchac have assisted clients across the State of Louisiana in obtaining funding of over $220 million through the State Revolving Fund (SRF) program. Louisiana’s Clean Water SRF loan program offers low-interest loans to communities for the construction or upgrade of wastewater treatment works and other water quality improvement projects. No other engineering firm in the State of Louisiana has done more projects with LDEQ’s SRF program than Manchac.

Texas Street Lift Station Rehabilitation

The scope of work for the City of Lake Charles included the following:

  • Remove existing pumps and replace with new dry pit submersible pumps
  • Demolition of existing building at the Texas St. Lift Station
  • Remove existing piping and valves and replace with new
  • Remove existing electrical and controls and replace and relocate with new
  • Clean, repair, and coat the wet wells.


Monroe North Area Sewer Improvements

The area north of Bayou Desiard (North Area) in the City of Monroe suffers chronic sanitary sewer overflows (SSOs) during heavy rain events.  In the 4th Quarter of 2009, a flow monitoring study was conducted to identify and quantify wastewater in the sewer basins of the three major pump stations in the North Area.  To alleviate these SSOs, a Sewer System Evaluation Survey, with subsequent basin rehabilitation, is ongoing, and final design is underway to upgrade the three major pump stations.

The three lift stations are Forsythe #2, Highway 165 and River Oaks. The work also consists of the replacement of the River Oaks Forcemain. Upgrade work at the Highway 165 and River Oaks Lift Stations consists of replacement of the existing pumps and installing new instrumentation and controls. The work at Forsythe #2 consists of the construction of a new lift station at the same site.

  • Evaluation of capacity of treatment and collection system
  • Wastewater modeling
  • Computerized wastewater model
  • O&M Manual Preparation
  • SCADA design
  • Developing GIS/CAD drawings
  • Prepare plans, specifications and cost estimates
  • Shop drawing review
  • Construction consultation and inspection
  • Project record drawings


Inland Raw Water Pump Station Evaluation & Design

Manchac Consulting Group, Inc. was hired by Bossier City to provide an analysis of its North Raw Water Pump Station on the Red River. This pump station currently has a capacity of 48 MGD and provides raw water from the Red River to the City’s reservoir. The pump station was originally constructed in 1955 and is in need of rehabilitation or replacement.

Several alternatives were evaluated as part of Manchac’s work:

  • Construction of a new inland pump station with a horizontal collector well
  • Construction of a new inland pump station with a screened raw water intake
  • Upgrade of the existing pump station

Manchac, working with Ranney Collector Wells, provided the City with a design report covering all aspects associated with the three scenarios evaluated. Since it was determined that the soil strata in the area near the North Raw Water Pump Station is not conducive to a collector well, Manchac recommended the construction of a new inland pump station with a screened raw water intake at the existing water treatment plant. The design of the new 50-mgd raw water intake and pump station was complete in 2013 and the project moved to construction in the spring of 2014. The pump station was constructed using a sunken caisson (30 feet diameter and 60 feet deep) and micro-tunneling for the new raw water intake line. The $8 million project was completed in the fall of 2015.


Northeast WWTP Headworks Rehabilitation Design & Construction Management

Manchac Consulting Group was retained to provide engineering services for the rehabilitation of the concrete, gate structures and odor control system at the City of Bossier City’s Northeast WWTP.  This project also included design of a temporary bypass pumping system while the headworks was taken out of operation during construction.

Manchac was authorized in March of 2010 to prepare plans and specifications for the rehabilitation of the headworks structure at the NE WWTP in Bossier City. The headworks structure had been subjected to high levels of H2 S gases causing extensive corrosion to the structure. Plans and specifications were prepared in accordance with the contract requirements of 180-days. Manchac also assisted Bossier City with procuring a loan through the State Revolving Fund program at LDEQ. Once the loan was closed in late 2010 and the funds for the project were secured, the advertisement-for-bids was released, and the NTP was issued to the contractor February 21, 2011.  Construction was completed on this project in August of 2011, with a close-out contract value of just over $1 million (Manchac’s cost estimate on the project was $1.34 million).

The plans and specifications prepared by Manchac consisted of:

  • cleaning, repairing, and coating approximately 4,700 square feet of the interior walls of the influent pump station wet well and flow splitter box
  • cleaning, repairing, and painting the exposed force main piping, the piping in the influent pump station wet well, crane structure, and all other previously painted exterior surfaces
  • removal and reconstruction of the top of the covered flume of the flow splitter box
  • rehabilitation of the existing odor control system and removal and replacement of existing odor control air duct piping at Plant 1
  • replacement of four slide gates and a 1-ton bridge crane hoist
  • installation of approximately 195 linear feet of handrails
  • temporary removal and re-installation of the electrical raceway and wiring along the top of the flow splitter box
  • removal of the grit/sludge in the influent pump station wet well and haul to the drying beds off site
  • temporary by-pass pumping and piping
  • removal of the submersible pumps and associated wiring, delivery of the pumps and wiring to pump manufacturer’s shop for refurbishment, and the return of the pumps and wiring back to the project site for reinstallation


CDBG Lift Stations Improvement Project

The City of Lake Charles retained Manchac Consulting Group, Inc. to evaluate eight wastewater lift stations for mechanical improvements and electrical and control system improvements to prevent future flood damage during flood events associated with natural disasters.

The scope of work included the following:

Mechanical Evaluation – Mechanical improvements included installation of new dry-pit submersible pumps to enable the pumping of wastewater during flood events at the following pump stations:

  • Contraband
  • 7th Avenue
  • Colletta
  • Cline
  • Goos
  • Holly Hill
  • John
  • Creole

Electrical and Control System Evaluation – Electrical improvements included elevating the control panels and switchgear above flood levels at the following pump stations:

  • Contraband
  • Colletta
  • Goos

City of St. Gabriel - Sunshine WWTP Expansion Improvements

Manchac Consulting Group was retained by Iberville Parish to design the upgrade to the City of St. Gabriel’s WWTP.  This project was funded though HMGP funds.  It included new effluent pump station and forcemain design over the Mississippi River levee and associated permitting.

Lake Charles Biosolids Management Plan

Manchac was retained by the city to develop a plan for disposal of the city’s wastewater biosolids. Several alternatives were evaluated and a recommendation was made to the city.

Monroe Water Distribution System Model

Manchac worked closely with the City of Monroe to evaluate all pertinent city data in order to provide the most complete hydraulic model update. The hydraulic model was updated and used to evaluate system components to determine what infrastructure needs were required to provide additional capacity to outside bulk users. The modeling project was completed within a very limited time frame to provide the City with the information necessary to accommodate the bulk users.

City of Lake Charles Water Distribution System Hydraulic Model

Manchac was retained by the City of Lake Charles to provide a water distribution system model. Current and future demands will be evaluated, and recommendations for system improvements will be made.

Toledo Bend Lift Station, Waterline Replacement and WW Collection Line Replacement

Manchac Consulting Group, Inc. served as a sub-consultant providing design services on a number of design/build projects for American Water at Ft. Polk in Leesville, LA. The design work included water and sewer line extension projects and all associated permitting. Inspection services were provided to American Water as a third party service on design/build projects.