Title
Requisition Nos. REQ-0002565, REQ-0003295, REQ-0003302, REQ-0003341, REQ-0003401
Aluminum Sulphate
O&M
Body
Agenda of: April 23, 2025
Item No.: 2025-112
Amount: $19,771,178.90
TO: The Honorable
Board of Directors
Great Lakes Water Authority
FROM: Suzanne R. Coffey, P.E.
Chief Executive Officer
Great Lakes Water Authority
DATE: March 27, 2025
RE: Requisition Nos. REQ-0002565, REQ-0003295, REQ-0003302, REQ-0003341, REQ-0003401
Aluminum Sulphate
Vendor: Chemtrade Chemicals US LLC, PVS Nolwood Chemical, Inc.
Status: New Contract/PO
MOTION
Upon recommendation of Cheryl Porter, Chief Operating Officer - Water and Field Services, the Board of Directors (Board) of the Great Lakes Water Authority (GLWA), authorizes the Chief Executive Officer (CEO) to enter into REQ-0002565, REQ-0003295, REQ-0003302, REQ-0003341, REQ-0003401, "Aluminum Sulphate" with Chemtrade Chemicals US LLC, PVS Nolwood Chemical, Inc., at a cost not to exceed $19,771,178.90 for a duration of three (3) years and two (2) months; and authorizes the CEO to take such other action as may be necessary to accomplish the intent of this vote.
BACKGROUND
Aluminum sulfate (also referred to as liquid alum), when added to raw water, reacts with the alkalinity present in water and forms a gelatinous precipitate. The large particles of suspended matter in raw water can be removed by allowing them to settle out in a sedimentation basin. However, there are smaller particles in surface water that do not settle out within a reasonable time without some help to accelerate the process. These smaller particles, normally referred to as non-settleable solids, usually consist of a combination of biological organisms, bacteria, viruses, protozoan, color, organic matter and inorganic solids. The term turbidity is applied to all suspended matter in water. To effectively remove the suspended solids (turbidity), the size of the smaller particles needs to be increased. The difficulty with this is the par...
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