Civil Engineering Reference
In-Depth Information
Any expected water quality changes over the life of the facility
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Seasonal operational changes, if they exist, such as temperature, pH, or other
water quality parameters
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Any potential water quality changes due to blending of multiple wells or water
sources
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Aeration requirements (if used)
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Chemical dosage requirements, including:
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Oxidation chemical dosing points
Coagulant chemical dosing points (if used)
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Required detention or reaction times
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Selected chemicals
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Dosing quantity
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Filter characteristics
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Pressure or gravity filters
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Effective media size
Media material
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Media uniformity coefficient
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Media depth
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Hydraulic characteristics
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Detention tank volume (if used)
Clarifier / flocculator requirements (if used)
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Filter loading rates
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Filter run characteristics
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Empty bed head loss
Head loss / pressure loss buildup during filtration over time
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Length of filter run
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Backwash requirements
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Backwash rates (low and high)
Air scour requirements (if used)
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Length of backwash
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Filter-to-waste requirements
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Filter recovery rates
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Washwater residual characteristics
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Quantity of suspended solids (amount per volume of water produced)
BOD
5
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Settleability
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Pilot-testing units can be set up to examine several different iron and manganese
removal processes. This will allow the utility to select the process that will best serve
their needs and will be the most cost-effective to build and operate. Often, especially
with difficult water qualities, pilot testing becomes an exercise in trial and error as the
engineer looks for the right combination of process, aeration, chemicals, chemical
dosing locations, detention times, filter loading rates, media, and filter run lengths to
