2016 ASHRAE Winter Conference

The UK has had a number of serious Legionella outbreaks over the past five years. After a major inquiry that managed to identify the causes, a guide was written and a program of information dissemination ensued. Unfortunately there have been further outbreaks and further guidance. The Health and Safety Executive has now published HSG 274, the Approved Code of Practice - ACOPS - which is the most definitive document and is a UK legal requirement. This presentation will describe the approach and the detail which this guide goes into to ensure high levels of protection.

Legionnaire’s disease is again a topic of great interest to IAQ practitioners as the incidence of this disease worldwide is on the rise. Public Works and Government Services Canada has issued a guidance document , MD 15161, on the design, operation and maintenance of building water systems in order to prevent the growth of Legionella bacteria. This presentation will focus on the inspection of building water systems, the evaluation of their associated risks and the creation of a Legionella bacteria control management plan (LBCMP) for any given building.

While the risk management approach and water management program outlined in ASHRAE Standard 188-2015 will go a long way in preventing Legionnaires’ disease, there are many common mistakes and misconceptions that can subvert a successful program. The basic principles underlying the key elements of Standard 188 will be reviewed as well as the common assumptions and measurement errors that can lead to missed opportunities to implement effective controls. Case studies will be presented that exemplify both successful and failed programs.

The American Industrial Hygiene Association (AIHA) published a guideline for the “Recognition, Evaluation, and Control of Legionella Hazards in Building Water Systems” in June 2015. This guidance updates and expands upon information previously used to conduct environmental source assessments for Legionella during outbreak investigations. It also provides a framework for competent professionals to establish a proactive assessment strategy of hazard assessment and longitudinal monitoring of building water systems. The intent is that they use it to develop evaluation and assessment strategies for Legionella and shift to a proactive approach that may reduce the impact this disease has on public health.