Circular Clarifiers and Thickeners

New, rebuild, & retrofit designs for nearly all clarifier and thickener applications

Monroe Circular Clarifiers use widely accepted settling technology based on the density difference between water and suspended solids. The Monroe Clarifier is designed to give you the performance you require with long-term reliability. Monroe Environmental realizes that all waste streams are not alike and in many cases standard designs must be modified. Tank sizing, influent and effluent arrangements, flocculation requirements, sludge removal, and skimming methods and mechanisms are some of the considerations necessary for a successful installation.

Circular Clarifier & Thickener Expertise

Monroe Environmental builds Primary and Secondary Circular Clarifiers for industrial and municipal wastewater treatment, as well as Flocculating Clarifiers and Solids Contact Clarifiers for clean water or potable water applications. Our experienced staff will provide high efficiency, low maintenance systems that will provide the highest return on investment.

The Monroe Clarifiers are available in self-supporting prefabricated steel units or they can be designed for installation in a concrete tank. Existing structures and systems can sometimes be utilized and upgraded for cost savings.

Circular Clarifiers normally utilize a center feed inlet well or a peripheral inlet. The center feed well design can be equipped with a chemical addition system with mixing and flocculation. With the center feed well, the effluent is discharged along the outer wall of the clarifier tank. Clarifiers with peripheral inlets will be designed with a center bottom liquid outlet.

Circular Clarifiers Engineered to Meet Your Needs

  • Customized designs for municipal and industrial applications
  • Tank diameter 10 to 250 feet
  • Full and half-bridge designs
  • Steel or concrete tanks
  • Chemical feed system available
  • Flocculator available when required
  • Energy Dissipating Inlet (EDI) designs available
    • MEDIC
    • LA-EDI
    • Alternate designs
  • Thickener mechanism available
  • Sludge removal configurations
    • Scraper
    • Spiral scraper
    • Suction header
    • Riser pipe
  • Skimmer mechanisms
  • Corrosion resistant materials and coatings
    • Epoxy coated steel
    • Stainless steel
    • Galvanization
  • Custom built replacement parts for all manufacturers
  • Clarifier rebuilds

Primary Wastewater Treatment Circular Clarifiers
Monroe Environmental’s Primary Circular Clarifiers are designed to receive raw wastewater after it has been pre-screened to remove large objects and grit. This primary sedimentation tank will produce a homogeneous liquid capable of being treated biologically and a sludge that can be separately treated or processed.

Secondary (Final) Wastewater Treatment Circular Clarifiers
Monroe Environmental’s Secondary Circular Clarifiers for wastewater are designed to provide a high quality effluent suitable for discharge to the environment or further treatment.
The Monroe Environmental Secondary Clarifier (often called ‘final clarifier’) effectively separates the biological floc and colloidal solids to produce wastewater with very low levels of organic material and suspended matter.

Solids Contact and Clean Water Treatment Circular Clarifiers
Monroe Environmental manufactures several types of water treatment clarifiers that combine chemical treatment, flocculation, and sedimentation. These units are heavily utilized in both industrial and municipal processes for treating groundwater, surface water, and process water, and include Flocculating Clarifiers and Solids Contact Clarifiers.


Monroe Environmental Circular Thickeners are a crucial step between upstream process clarifiers/separators and downstream de-watering and sludge conditioning processes. A well designed thickener provides storage and equalization, and reduces the costs associated with de-watering. Thickeners are similar to other circular clarifiers in appearance and operation, but typically require higher operating torque and alternate sludge collection designs for optimal performance.