Indicator 2.7.4

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System

Water Type

Feed Dependent

Species

Indicator 2.7.4

by Contact on 8 October 2026

Requirement

The UoC shall ensure that freshwater-wells used for culture water do not exceed a conductivity of 1,500 micro-mhos per centimeter (µmho/cm) or chloride concentration of 300mg/L. An exception applies where well-monitoring is not permitted by applicable law, in which case regulatory records shall be obtained to provide evidence of conductivity levels.

How Do I Interpret This Requirement?

  • Freshwater wells with a conductivity or chloride concentration above the thresholds in Indicator 2.7.4 will demonstrate that salinisation has taken place.

  • Specific conductance or chloride concentration should be monitored at a frequency adapted to fluctuations due to natural factors, such as seasonal rains.

Evidence of Implementation

  • Records of specific conductance of freshwater wells on, or in proximity to the site (within 1km radius).

    • Records should demonstrate monitoring has taken place at least every six months and considered natural factors, such as seasonal rains.

  • Regulatory records obtained where applicable, to demonstrate well-monitoring is not permitted by law.

    • Records shall contain evidence of conductivity testing.

Auditors Should Confirm

  • Monitoring records are available for freshwater wells in proximity to the site, which demonstrate either conductivity or chloride concentration is below the relevant threshold specified in Indicator 2.7.4.

  • Monitoring has taken place at least every six months and considered natural factors, such as seasonal rains.

  • Regulatory records are available for instances where well-monitoring is not permitted by law.

  • The records demonstrate conductivity testing has taken place.

Useful Resources

  • Hand-held refractometers can be used to measure salinity. These devices are appropriate for salinities of approximately 2 or 3 ppt, but they are not sensitive enough to determine if sites are causing the salinisation of freshwater bodies.

  • The quickest and easiest method to evaluate salinity of water is to measure specific conductance with a conductivity meter. An alternative method is a chloride test kit, which is typically cheaper.