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