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Filterworx performance filter

Overview System Components Specifications Industries & Applications Documentation & Tools


Product Features


  • Potable drinking water treatment
  • Tertiary wastewater treatment
  • Nutrient removal in water or wastewater
  • Reverse osmosis membrane desalination pretreatment
  • Water reuse
  • Biological Active Filtration (BAF) 

Water challenges addressed

  • Aging infrastructure
  • Harmful algal blooms
  • Water scarcity
  • Contaminants of emerging concern (pharmaceuticals, personal care products)
  • Cryptosporidium and giardia
  • Reduction of disinfection byproducts
  • Taste and odor

Leopold engineers have been at the forefront of gravity media filtration since 1924. With more experience than anyone in the industry, we can help you analyze, evaluate and design all aspects of your complete filtration system.

Evaluate influent water qualities, including seasonal changes and demand requirements, and determine the best pretreatment options.

Select the best media characteristics, media quality, bed composition, bed depth and grain size distribution to match the filter configuration, influent quality, pretreatment processes and required filtrate effluent quality.

Determine optimal loading rates and best design configuration to meet site conditions and operational requirements.

Design the backwash process to restore original head loss, maintain solids storage capacity and maximize filter runs while minimizing power costs and wastewater generation.

System Components

System Components

Backwash Water Troughs

Backwash Water Troughs

Our troughs help conserve media while removing backwash water efficiently. Made of durable fiberglass reinforced plastic (FRP), backwash water troughs are sized and configured to match your process needs.

Engineered Filter Media

Engineered Filter Media

We carefully evaluate your influent water characteristics and process requirements to determine the optimal media configuration, including depth, type, effective size and uniformity coefficient.

We can provide anthracite engineered media with the lowest uniformity coefficient in the industry.

A lower uniformity coefficient provides:

  • Superior filtration qualities
  • Increased filter run volumes
  • Less water required to thoroughly backwash

Less frequent and more efficient backwash saves energy and increases overall water production. 



Our flat-bottom flume reduces excavation requirements and support structures. This simplifies new construction, resulting in substantial cost savings. We can also design FilterWorx systems with front flumes, center flumes or H flumes, or even wall sleeves for conversion of an existing basin. We will carefully evaluate your site requirements to provide the most cost effective flume configuration.

I.M.S Media Retainers

I.M.S Media Retainers

  • Replace up to 14 inches (36 cm) of media support gravel allowing for the same media depth in less vertical space, reducing construction costs.
  • Compatible with all Leopold underdrains, I.M.S media retainers are factory installed on the Leopold underdrains saving time and labor during installation.
  • Provide even backwash distribution to deep clean filters.

Two sizes for different applications

I.M.S 200 media retainers with 0.2 mm slots are specifically designed for drinking water treatment including biologically active filters and water reuse. It retains media of effective sizes down to 0.4 mm.

I.M.S 1000 media retainers with 1 mm tapered slots are specifically designed for wastewater treatment applications, including the Leopold elimi-NITE® 2.0 denitrification system. It retains media of effective size down to 1.7 mm. 

System Controls

System Controls

System Controls and Process Optimization Efficiency: The Leopold FilterWorx control system optimizes filtration process as well as operating costs. By continuously monitoring filtrate quality and filter bed conditions, the filter is backwashed only when, and as long as needed. Filtrate quality and filter run volumes are optimized while reducing energy consumption and wastewater generation. Our controls keep the filter media well-conditioned, extending the life of the filter, all while lowering operating costs.

Complete integration: By using standard communication protocols the FilterWorx control system seamlessly integrates into the overall plant SCADA systems, while providing the option of local control to ensure processes remain in operation even if there’s an issue in the primary SCADA system.

Advanced process control: By combining our FilterWorx control system with Xylem’s advanced process analytics and control algorithms, we are able to offer two of the most advanced biologically active filtration systems on the market, the Leopold elimi-NITE® 2.0 denitrification system for nitrate removal in tertiary wastewater and the Leopold Oxelia® ozone enhanced biologically active filtration system for water reuse, sensitive receiving streams, and potable water treatment. 



 Leopold features four types of underdrains to meet any configuration need.

Underdrains collect filtered water during the filter run, and distribute air and water during the backwash cycle.

  • Superior air and water distribution for effective backwash and less than +/- 5% maldistribution, guaranteeing no dead zones in all lateral length.
  • Cleaner filters have longer filter runs which means more filtered water, less waste. This lowers your overall operating costs.
  • Air flow adjustability allows you more control and saves energy and water. Air scour rate can be adjusted from 2 to 5 scfm/sq.ft. (0.6 to 1.5 m/min), enabling collapse pulse cleaning during concurrent air/water backwash with various media configurations. Air scour provides higher shear forces and cleaner media, with less backwash water.
  • Faster installation with fewer parts than nozzle systems and no false floor. Underdrain blocks are lightweight for easy handling and snap together for quick installation, shortening construction time and putting you in production quicker.
  • Design flexibility with different heights to allow for different combinations of lateral lengths and vertical filter heights, as well as different flume configurations and installation techniques.


General Information
Filterworx performance filter
Potable Water, Wastewater, Desalination Pretreatment
Flow rate
1 MGD+ (3,788 m3/day+)
Contaminates removed
Potable Water: Particulate, Turbidity, Organics, Iron, Manganese, TOC; Wastewater: Total Suspended Solids, Ortho-phosphorus, Nitrate, Organics; Desalination Pretreatment: Particulate, Silt, SDI reduction
Process warranties offered
Warranties on effluent quality
Single source responsibility
Yes, to supply all system components
Types of backwash suitable
Water only, sequential air followed by water, concurrent air/water and sustained air/water
Standards met
AWWA, ASTM, British DWI, French
Flume types suitable
Flat Bottom Flume, Front Flume, Center Flume, H-Flume
Construction type
New or existing regardless of current underdrain type
System Components
Filterworx performance filter
Dual parallel lateral underdrain available
Type 360, Type XA , Type S, and Type SL
Media support systems available
Graded gravel, I.M.S 200 media retainer or I.M.S 1000 media retainer
Types of media that can be used
Silica Sand, High density sand, Anthracite, Granular Activated Carbon, Expanded Clay
Trough types
Fiberglass, Stainless Steel
Media retention available
Yes, stainless steel
Control system
Automatic, Manual, Semi-Automatic
Valve actuator
Electric, pneumatic, hydraulic
Flow measuring instruments
Venturi, Mag-meter, transit time
Turbidimeters, Particle Counters, Nitrate, Phosphorus, TOC, DO
Blower types
Positive Displacement, Centrifugal
Pump types
Submersible, end suction, split case, vertical turbine
Industries & Applications

Industries & Applications

Recommended Industries and Applications

Reuse > Tertiary Treatment Filtration
Media Filtration
Potable / Drinking Water > Filtration Media Filtration
Documentation & Tools

Documentation & Tools