71Procedure for responding to detection of high heterotrophic colony count

71 Procedure for responding to detection of high heterotrophic colony count (1) This regulation applies if— (a) a responsible person is notified by an initial laboratory report or the Secretary that the heterotrophic colony count of a sample of recirculating water taken from a cooling tower system exceeds 200 000 colony forming units per millilitre; and (b) the recirculating water has not been manually treated with additional quantities of biocide or with an alternative biocide during the period between the sample being taken and the notification. (2) Within 24 hours of receiving a notification, the responsible person must ensure that the following procedure is implemented— (a) the recirculating water is treated with additional quantities of biocide or with an alternative biocide; (b) the water treatment program, tower operation and maintenance program of the cooling tower system are reviewed; (c) any faults are corrected; (d) any changes necessary to prevent a re‑occurrence of those faults are implemented. (3) Between 2 and 7 days after receiving a notification, the responsible person must ensure that a further sample of the recirculating water is taken and provided to a laboratory to determine the heterotrophic colony count of the recirculating water. (4) Within 24 hours of receiving a report from a laboratory that a sample taken in accordance with subregulation (3) has a heterotrophic colony count exceeding 200 000 colony forming units per millilitre, the responsible person must ensure that the recirculating water is disinfected. (5) Between 2 and 7 days after the recirculating water has been disinfected in accordance with subregulation (4), the responsible person must ensure that a further sample of the recirculating water is taken and provided to a laboratory to determine the heterotrophic colony count of the recirculating water. (6) If a laboratory has tested a further sample of recirculating water in accordance with subregulation (5) and reports that the heterotrophic colony count of the sample still exceeds 200 000 colony forming units per millilitre, the responsible person must— (a) ensure that the disinfection and testing procedures set out in subregulations (4) and (5) are repeated until the heterotrophic colony count of the recirculating water does not exceed 200 000 colony forming units per millilitre in 2 consecutive recirculating water samples taken approximately one week apart; or