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Quality Filter Materials

Unifilt manufactures,
packages and ships
quality filter materials
including Anthrafilt
anthracite filter

AWWA Member NSF Certified NSF/ANSI 61

Our experienced team is dedicated to your
complete satisfaction. Our wide variety of filter
materials meets or exceeds AWWA B100-09
and are listed under NSF Standard 61.

Anthracite Filter Coal

Composed of specially selected and graded hard, durable anthracite coal particles. The anthracite shall have an average specific gravity of 1.60 (or more), with hardness (MOH Scale) of 3.00 or more, and shall be essentially free of iron, sulfide, clay, shale, extraneous dirt, and excessive dust, and shall be in strict accordance with AWWA B100-09. Carbon Content shall be a minimum of 80% on a dry-weight basis. Ash Content shall be a maximum of 15%. Volatile Matter shall be 7% maximum on dry-weight basis. There shall be not more than 3% float when placed in a fluid of specific gravity of 1.45, and not more than 3% sink when placed in a fluid of specific gravity of 1.95, when tested in accordance with ASTM D4371-84, Methods for Determining the Washability Characteristics of Coal. The filter anthracite shall be processed with wet washing, screening and biological neutralization. The durability or friability shall be less than 3%.

Filter Sand, Torpedo
Sand and Coarse Sand

Composed of hard, durable clean siliceous particles free of all mica with an average specific gravity of 2.60 (or more) and shall be in strict accordance with AWWA B100-09 standards. The acid solubility shall be less than 5%. The loss of ignition less than 4%.

Greensand Plus

A purple-black filter medium processed from glauconitic greensand and is used for removing soluble iron, manganese and hydrogen sulfide from well water supplies. The effective size is 0.30 - 0.35 mm with a uniformity coefficient of less than 1.60. The specific gravity will be approximately 2.4.

High Density Material

Composed of hard, durable uncoated grains and shall contain not more than 5% of flat particles and not more than a total of 1% of clay, loam, dust and other foreign matter, and shall comply with AWWA B100-09. Acid solubility shall not exceed 5% and shall have a specific gravity of 3.80 or more.

Support Gravel
Filter Gravel

Consist of clean, hard, durable rounded particles of high quality, which shall exceed AWWA B100-09, and be consistent with the recommendations of the underdrain manufacturer. The average specific gravity shall not be less than 2.5 for Silica Gravel. The acid solubility shall be as specified in B100-01.

Unifilt Poly Bags Unifilt Semi Bulk Packaging Unifilt Flexible Shipping Logistics

Choose from these packaging options.

Remember, any media that’s stored in sunlight prior to installation should be covered with UV-resistant tarpaulin.


Anthracite bags are color-coded so standard sizes can be easily differentiated.

  • Anthracite - 52lbs. per bag
  • Greensand Plus - 45lbs. per bag
  • High Density Material (garnet) - 50lbs. per bag
  • Filter Sand and Gravel - 50 to 100lbs. per bag


Sturdy enough for double-stacking, sacks come with top lift straps and self-discharging bottom spouts, unless other arrangements have been made.

They are treated with ultra-violet light inhibitors and ship standard without pallets. Upon request, we can provide product on pallets with optional stretch wrap.

  • Anthracite and Greensand Plus - 1 ton per sack
  • Filter Sand, High Density Material (garnet) and Gravel
    up to 2 tons per sack

Take advantage of flexible delivery and shipping.

The company-owned fleet ensures reliable logistics and superior flexibility. Feel free to order filter media in full or mixed loads to meet your specific needs. Unifilt loads trucks, railcars, intermodal and overseas containers.