Wastewater / Municipal & Federal

Wastewater Treatment Plants

*Headworks, aeration basins, clarifiers, digesters and disinfection systems, built within permit constraints and next to operating process trains.

Overview

What we deliver

Wastewater treatment is our fastest-growing line of work. We have built secondary and tertiary plant expansions, membrane bioreactors, biosolids facilities, and the headworks and effluent systems that support them. The largest plant we have expanded treats 46 MGD at peak flow.

Process knowledge matters

Our project teams include engineers and superintendents who have spent years in treatment plants. They understand why a clarifier launder must be level within a sixteenth of an inch, why a digester roof requires gas-tight detailing and why you do not tie into an active force main on a Monday. This knowledge is as valuable in pre-construction as it is in the field.

Structures, mechanical and controls

We build cast-in-place and precast concrete basins, post-tensioned digesters and prestressed tanks to ACI 350 and ACI 372 requirements. Mechanical equipment, including blowers, mixers, pumps, screens and clarifier mechanisms, is installed by our millwrights and piping crews with factory representatives on site. Electrical and instrumentation work is subcontracted to preferred partners and coordinated through our commissioning team.

We have commissioned biological nutrient removal (BNR) systems, anaerobic digestion with combined heat and power, and biosolids drying. We schedule start-up and seeding with operations, and we stay on site through performance testing so the system meets effluent limits.

Scope

Headworks: screening, grit removal, flow measurement
Primary and secondary clarifiers
Aeration basins and BNR process trains
Membrane bioreactors and tertiary filtration
Anaerobic digesters, gas handling and CHP
Biosolids thickening, dewatering and drying
UV and chemical disinfection, outfalls and diffusers
Odor control and chemical systems

Technical

ACI 350 and ACI 372 structures, including post-tensioned tanks
Clarifier and launder tolerances
Fine-bubble diffuser grids and blower systems
Hazardous-area classification for digester gas
Confined-space entry and H2S monitoring programs
Corrosion-resistant coatings, liners and FRP
Process tie-ins with bypass pumping
SCADA integration, loop checks and functional testing
Performance testing and seeding support

Delivery: CM/GC, Progressive Design-Build, Design-Bid-Build
Typical value: $25M–$100M
Self-performed: Yes

Questions

Frequently asked questions

01 How do you manage odors during construction?

We coordinate with plant operations to schedule odor-generating tie-ins for favorable conditions, use temporary covers and scrubbers when necessary and maintain a complaint line that is answered by someone who can act.

02 What experience do you have with digesters?

We have built conventional and egg-shaped anaerobic digesters, including post-tensioned concrete designs. Our crews are experienced with gas-tight penetrations, mixing equipment and the safety requirements for hazardous areas.

03 Do you handle start-up and performance testing?

Yes. We schedule start-up, seeding and performance testing with the owner and supplier representatives, and stay on site until the process meets the contract requirements.

04 Can you build while the plant meets its NPDES limits?

This is the norm. We build around operations with detailed tie-in plans, temporary process controls and bypass operations designed so that effluent quality is protected at all times.