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Amy Vail

City of Cadillac

Lab Manager

Overview� Sampling

� Pretreatment

� Seeding

� Procedure

� Blanks

� Glucose-Glutamic Acid

� Duplicates

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Sampling� Location

� Size

� Preservation

� Hold Time

Pretreatment� Representative Sample

� Mixing

� Dilutions

� Temperature

� pH Adjustment/Seeding

� Dechlorination/Seeding

� Nitrification Inhibitor

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Seeding� Purchased/Use Own

� Depletion of 0.6-1.0 mg/L per mL of seed

� Run a GGA on seed

� Seed control bottle

� Don’t add to dry bottle

Procedure� Consistency

� Cleanliness

� Bottles

� Valid Results

� 1.0 mg/L Residual

� 2.0 mg/L Depletion

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Procedure� Dilution Water

� Make Up (CBOD v. BOD)

� Aeration

� Storage

� Nutrient Mixture

Procedure� Dissolved Oxygen Measurement

� Calibration

� Winkler

� Electrode

� Measurements

� Stirring

� Rinsing

� Blank Recheck

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Procedure� Preparation for Incubation

� Water Seal

� Capping

� Incubation

� 20 +/- 1°C for 5 days +/- 6 hours

Blanks� <0.2 mg/L Depletion

� Glassware

� Supersaturation

� Temperature

� Atmospheric Pressure

� Contaminated Source Water

� Nitrification Inhibitor

� Procedure/Operator Difference

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Glucose-Glutamic Acid� 198 +/- 30.5 mg/L BOD/172 +/- 30.5 mg/L CBOD

� Seed too strong/weak

� Making solution improperly

� Procedure

Duplicates� Consistent Source

� Consistent Procedure

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Any Questions?� Amy Vail

� City of Cadillac

� (231)775-2368

� lab@cadillac-mi.net