Global food production facility

A major global food production factory with multiple cooling systems has a long history of contaminated process water issues. Recycled, treated factory effluent water serves 12 cooling towers being chemically treated to control bacterial activity and meet health and safety guidelines for the control of Legionella Pneumophila.

The challenge

Continuous sodium hypochlorite (14%) addition from multiple dosing points was failing to consistently maintain microbiological activity below 10,000 organisms per ml. Regular shock doses of peracetic acid were required in an effort to gain system control, consuming 4 metric tonnes per month. The existing biocide regime was costly, complex and failing to deliver consistent results.

The outcome

Over four weeks, Chlodox D2 consumption was reduced by 77% compared to the hypochlorite regime. Peracetic acid was no longer required to maintain bacterial counts below 10,000 organisms per ml. After 14 months of permanent Chlodox D2 dosing, consistent bacterial control below regional Legionella guidelines continues to be achieved.

Context: the cost of preventable corrosion

Industry data puts 35% of corrosion damage as preventable through effective treatment, with an estimated $375 to $875 billion global annual cost of preventable corrosion. A single Legionella outbreak carries an average direct cost of $3.4 million, and unchecked scale build-up can raise chiller energy consumption by 7 to 10%.