Bids Are Invited For Due To Time Of Use, The Steel Plates That Delimit The Bottom Of The Filter Are Seriously Compromised, The Crepines Have Come Loose And A Large Part Of The Filtering Materials Have Flowed Along With The Filtered Water.; Considering That Filtration Corresponds To The Last Stage Of The Treatment Process And Has The Function Of Removing Suspended Particles, Colloidal Particles, Chemical Precipitates And, Mainly, Cysts And Oocysts Of Cryptosporidium And Giardia, The Water Treatment Process In Module Iii Was Interrupted, Therefore, There Is An Urgent Need To Renovate The Filters, With The Implementation Of Structural Blocks At The Bottom Of Them And Replacement Of The Filtering Material.; ; Note: Follows Rq 1897/2026

Sand Made Up Of Grains Of Siliceous Material; Free From Impurities Such As Clay, Mud And Organic Matter; Solubility In Hcl Should Be Less Than 5% By Mass; Actual Specific Mass Greater Than 1.3 G/Cm3; Effective Size Between 0.45 And 0.50 Mm; Uniformity Coefficient Between 1.4 And 1.6. Delivery In 1,000 Kg Packages (Big Bag). The Materials Must Be Suitable For Use In Water Treatment Systems For Human Consumption, That Is, In Accordance With What Is Established In Ordinance Gm/Ms No. 888, Of May 4, 2021, The Supplier Must Prove This Suitability By Presenting A Safety Report (According To Ansi/Nsf 61 Criteria Or Certification Of The Material By A Product Certification Body (Ocp) Recognized By Inmetro), Stone Made Up Of Grains Of Siliceous Material; Free From Impurities Such As Clay, Mud And Organic Matter; Solubility In Hcl Should Be Less Than 5% By Mass, Effective Size Between 1.5 To 2.0 Mm, Coefficient Of Uniformity - C.U. ≪= 1, 5. Delivery In 1,000 Kg Packages (Big Bag). The Materials Must Be Suitable For Use In Water Treatment Systems For Human Consumption, Effective Size Between 1/8 And 1/4