Filter Sand is primarily specified by effective size and a uniformity coefficient. By definition, effective size is that opening (in mm) that will pass 10% of a representative sample of a filter material. Uniformity coefficient is a ratio of the size opening (in mm) that will just pass 60% of a sample divided by the opening that will pass 10% of that sample.
Silica sand shall have a specific gravity of greater than 2.50 and an acid solubility of less than 5%.
Silica shall be visibly free of clay, dust, micaceouos and organic matter.
Edgar Minerals Inc. is a NSF Standard 61 Certified facility, and manufactures filter sand meeting specifications in accordance with AWWA B-100.