Quality Control

Biological Sampling

Fecal Coliform

1. Training
1. Professional aquatic biologist at training
2. Standardized training program with same instructor
3. Regular checks of technicians
2. Field Procedure
1. Replicate samples
1. Samples from similar sites but not exact same spot
2. Duplicate samples
1. Three samples from the same site, taken with the same methods, one immediately after the other
3. Documentation
1. Accurate data
2. Careful observation
1. Factors affecting water quality
2. Accurate recording using prescribed terms
3. Lab Procedures
1. Aseptic techniques
1. Buffer water, filter apparatus and glass petri dishes sterilized before starting (preferably with an autoclave or steam sterilizer.)
2. Working surface disinfected with alcohol
3. Discard first two absorbent pads from dispenser to assure sterilization
4. Sterilize forceps after each use
5. Close windows to prevent airborne contamination
2. Control samples
1. Negative control sample
1. To check for sterile conditions
1. Sterile buffer sample should have zero colony count
2. Run at beginning and end of sample run
3. Run after every 10 samples
2. If negative control does grow bacteria - any sample processed before the control plate is invalid
3. Positive control sample
1. To check for growing of FC bacteria
1. Check expiration date of media
2. Store media at 5oC
2. Run sample of known E. coli
1. Inoculate 100mls of sterile buffer water with sterile stick or sterile inoculating needle dipped into tube of bacteria
3. Read control plates before sample plates
1. If positive control does not grow bacteria - any sample processes before  that plate is invalid
4. Split samples
1. Dividing sample taken in accordance with your standard methods into two bottles
5. Calibration
1. Calibrate thermometer for water bath incubator annually with NIST  thermometer
2. Calibration check for thermometer on water bath both beginning and end of 24  hour period
6. Reading plates
1. Count only colonies showing fecal coliform characteristics
2. Eliminate debris on plate
3. Read with dissecting scope
4. Have two technicians read plate
1. Readings should be within 10% or reread plate
2. Average two readings for final results
5. Plates overgrown with non-fecal coliform are recorded as confluent growth
6. Plates overgrown with E. coli are recorded as TNTO (too numerous to count)
7. For samples expected to be TNTO, add dilutions of at least 10 mls of sterile  buffer to filter the sample
4. Data Analysis
1. Use filtration log (attached)

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 QAPP Outline