MSD MISSISSIPPI FLOODWALL ORS PUMP STATION REHAB DESIGN BUILD

ST. LOUIS, MO The Mississippi Floodwall ORS Pump Station Rehabilitation Project consists of rehabilitation work for the Baden Pump Station, Harlem Emergency Closure Structure, and Mill Creek Pump Station, which is designed to provide system rehabilitation to accommodate a 100 year desired lifecycle while maintaining current operational function.

The project featured removal and replacement of roller gates and appurtenances at the Baden and Mill Creek locations. Roller gate replacements include a provision for water diversion within the structure, structure, actuator refurbishment, new stainless gates, rails, seals and assemblies, as well as structure modifications to accommodate the replacement. Roller gate replacement will occur sequentially to allow no more than one (1) gate to be out of service at a time per location. Emergency plans for stop log installation were created to ensure the integrity of the pump station system in the event of higher than normal river levels during these months. Slide gate rehabilitation are exclusive to the Harlem Emergency Closure Structure. These gates require actuator refurbishment at two locations, as well as seals, blocks, alignment and other modifications at all four gates. In addition, concrete and stop log slides were also rehabilitated at this site. The refurbishment of the Harlem slide gates included the extraction of existing gates to allow access for seal replacements and adjustments. River and stormwater diversion for the concrete and stop log work will be required at the Harlem location along with an emergency action plan for irregular river water levels.

Access to Shutter Gates and upper chamber will be enhanced by the installation of larger opening at the actuator slab elevations. These openings within the existing structural slab were cut between existing beams and dressed with new steel closures, grating and permanent handrail. The new opening will allow MSD for eased future access for maintenance and modifications. Roller Gates within the lower well will require a water diversion system to accommodate fluctuation in river levels. Diversion systems included structural panels that mount to adjacent existing structure with the ability to provide dry working conditions up to RS20 at Baden and RS16 at Millcreek. Work within the diversion structure included the rehabilitation of existing stop log channels, removal and reinstallation of gate rails, and concrete remediation. Hydraulic actuators from the Baden Pump Station and Harlem Closure Structure required refurbishment from the original manufacturer.

PERUQUE CREEK GRAVITY SEWER

OFALLON, MO Gonzalez Cos. designed a 6,000-ft long sanitary interceptor for the City of O’Fallon, Missouri. The 30-inch gravity sewer receives pumped sewage from Public Water Supply District No. 2 of St. Charles County (PWSD2) and discharges to an existing City sewer at Peruque Creek.

The need for a new sewer was determined through Gonzalez’ planning studies and hydraulic analysis of an existing lift station and interceptor sewer. The studies considered dry and wet weather capacity, sewerage demand from anticipated land development, and projected flows from PWSD2. After evaluating alternative sewer alignments, Gonzalez prepared complete bid documents, including alternate bid items for conventional and trenchless construction methods. Working with subconsultants, Gonzalez furnished surveys, soils investigations, Section 404 and Missouri DNR permitting, and easement documents. Submittal reviews and consultation were provided during construction.

Excavation depths ranged up to 22 feet, with a varying rock profile and areas of poor surface drainage. A key issue was the maintenance of tractor-trailer access and the restoration of heavy concrete pavement in an industrial area. The alignment crosses sensitive residential yards, forested bottomland, and a rocky hillside. A vortex structure and several drop bowl inserts were provided for odor control and turbulence reduction. Other design features include streambank restoration, wetland plantings, vibration monitoring, and a 67-ft jack and bore. Construction was completed in late 2020 at an approximate cost of $2.5 million.

BISSEL AND LEMAY FLUIDIZED BED INCINERATORS

ST. LOUIS, MISSOURI Gonzalez Companies provided overall program/ project support for the Bissel and Lemay Fluidized Bed Incinerators, which is the largest capital improvement project MSD has ever performed. Gonzalez supported Owner’s Representative team for the following services, administration, general advisory, project management plan, owner’ representative meetings,project controls, chartering workshop for program, preliminary conference, and public relations. Gonzalez also developed a scope of work and survey limits for any topographic and other surveys necessary for 30% design and RFP Documents.

Gonzalez used ASCE 38, “Standard Guideline for the collection and depiction of existing subsurface utility data” as a means to advise the owner on a recommended scope of work and procedure for the identification and mapping of existing utilities, to be carried out by design-builder.

Gonzalez provided surveys and developed basemap/site plan for use by engineer and integrated team to develop Pre-Design Report and Conceptual Documents. Gonzalez also provided pre design and conceptual documents for the following design components: Civil sitework,utility Requirements, and Sitework Design. Gonzalez will continue to provide project management and design assistance throughout all aspects of the project.

BIOSOLIDS PROCESSION SOLUTION

LOUISVILLE, KENTUCKY The Louisville and Jefferson County Metropolitan Sewer District’s (MSD’s) main treatment facility is the Morris Forman Water Quality Treatment Center (MFWQTC).  This plant provides biosolids processing for all treatment facilities operated by MSD.  MSD is committed to rehabilitating or replacing some of the existing biosolids processing facilities at the MFWQTC, which consist of sludge thickening, anaerobic digestion, solids dewatering, thermal drying, and marketing and distribution of the thermally dried pellets.  This system uses rotary drum dryers to produce heat-dried biosolids from the sludge generated at 5 MSD Water Quality Treatment Centers. MSD is committed to upgrading their solids processing to sufficient capacity for the MFWQTC through the year 2040.

Gonzalez Companies was part of the team that developed a Project Definition Document (PDD), which represents an approximate 10% design for the replacement of the aging biosolids processing facilities.  The 10% design document will be utilized by design-build entities to prepare bids.  Specific components addressed in the PDD include new solids screening equipment, pre- and post-dewatering centrifuges, thermal hydrolysis pretreatment, combined heat and power (CHP) capabilities and digestor complex retrofits/improvements.

PARAGOULD LIGHT WATER AND CABLE WASTEWATER TREATMENT PLANT 6MGD WWTP ULTRAVIOLET DISINFECTION SYSTEM

PARAGOULD, ARKANSAS Gonzalez developed the technical specifications for the bidding and pre-purchase of the UV equipment by PLWC. We then coordinated with the awarded equipment manufacturer to develop the design plans and specifications for the construction retrofit of the system. Gonzalez also provided PLWC with permitting assistance with the Arkansas Department of Environmental Quality (ADEQ) and Arkansas Department of  Health (ADOH), bidding assistance, and services during construction. 

WASTEWATER COLLECTION SYSTEM IMPROVEMENTS

WARRENTON, MO The City of Warrenton's wastewater collection system consists of over 63 miles of gravity-flow sanitary sewer pipe varying in size from 4-inch to 18-inch in diameter with almost 1,500 manholes.   The gravity sewer flows to seven lift stations, which includes one lift station at the WWTP.   Gonzalez provided the City with Facility Planning, Design, and Construction Management Services for the construction of a 4MGD lift station, 6,150 ft of forcemain, 11,200 ft of gravity collection sewers, and a new 12 MGD headworks.