Industry best practice manual for water quality management and sterilisation on-farm

  1. Home
  2. Docs
  3. Industry best practice manual for water quality management and sterilisation on-farm
  4. Troubleshooting water quality problems
  5. Shed issues: ineffective microbial treatment

Shed issues: ineffective microbial treatment

Table 36. Troubleshooting ineffective microbial treatment

Operational monitoring
ParameterTarget criteriaCritical limitsMonitoring method
Escherichia coli0CFU/mlSpecific chlorine residual set to achieve a minimum contact time requirement based on maximum flow and minimum storage timesOnline, continuous chlorine residual analyser, flow and pH.

24-hour monitored alarms on residual monitoring, pH and disinfectant dosing equipment.

Regular turbidity and temperature monitoring and disinfectant demand calculations.

Appropriate electronic or hard copy monitoring records.
Disinfectant residual1–2ppm
pHpH 6.5–7.5
Flow rateSet to achieve minimum contact time
Chlorine doseSet to achieve residual at end drinker
Turbidity<1 NTU
Corrective action

Any breach in critical limits or target criteria should result in any of the following operating procedures as necessary:
  • inspect and calibrate equipment,
  • adjust flow rate,
  • adjust the disinfectant dose or feed point,
  • carry out additional monitoring, increase sampling and testing,
  • recalculate contact time values,
  • implement unplanned maintenance procedure,
  • secondary or booster disinfection,
  • use alternative supply or divert water,
  • engage backup equipment,
  • plant automatic shutdown,
  • implement emergency response, and
  • record actions to be taken and report (internally or externally as required).
  • Verification

  • Calibration and maintenance of equipment
  • Drinking water quality monitoring
  • Satisfactory production
  • Evaluation and audit
  • Was this article helpful to you? Yes No

    How can we help?