Results

Interpretation

<102 Colony Forming Units per Litre

• Under Control

≥102 to ≥103 Colony Forming Units per Litre

• Resample and keep under review.
• Advised to drain, clean and disinfect.
• Review control & risk assessment;
• Carry out remedial actions identified.
• Refill and retest next day and 2-4 weeks later.

>103 Colony Forming Units per Litre

• Immediate closure. Exclude public from pool area
• Shut down spa pool.
• Shock the spa pool with 50mg/l free chlorine
• Circulating for 1 hour or equivalent.
• Drain, clean and disinfect.
• Review control & risk assessment;
• Carry out remedial actions identified.
• Refill and retest next day and 2-4 weeks later.
• It may be advisable to alert the local Health Protection Unit.
• Keep closed until legionellae are not detected

Results

Interpretation

Colony count at 37°C > 10cfu/ml

If a colony count above 10cfu/ml is the only unsatisfactory microbiological result, and residual disinfectant and pH values are within recommended ranges, the water should be retested.

Colony count at 37°C >100cfu/ml

Check treatment system and manual testing results records immediately and implement any remedial action as required.

Coliforms and E. coli present (>1cfu/100ml)

Occasional positive samples may occur if the spa pool has been sampled immediately after a contamination event before the disinfection system had time to be effective. A repeat sample should be taken whenever coliforms have been detected.

Coliforms >10cfu/100ml

A coliform count of up to 10cfu/100ml is acceptable provided that the residual disinfectant and pH values are within recommended ranges, there are no E. coli present and the aerobic colony count is <10/ml.

Coliforms present on repeat test

If coliforms are found on a repeat test it indicates that the disinfectant regime is ineffective. The spa pool systems and risk assessment should be reviewed and the spa pool taken out of action, drained, cleaned and disinfected before resampling.

P. aeruginosa present (>50cfu/100ml) with or without raised coliform, E. coli or colony count

Take spa pool out of operation, The spa pool systems and risk assessment should be reviewed and the spa pool should be drained, cleaned and disinfected before resampling.

Cryptosporidium or Giardia

Take spa pool out of operation immediately and seek advice of a public health microbiologist over the appropriate disinfection procedures.