Section 5.4 Disinfection with Chlorine Dioxide

The following are general recommendations for cleaning FilmTec™ NF 200 and NF270 Elements. More detailed procedures for cleaning a nanofiltration (NF) system are typically included in the operating manual provided by the system supplier. It should be emphasized that frequent cleaning is not required for a properly designed and properly operated NF system, however because of the NF 200 and NF270 membrane’s unique combination of pH range and temperature resistance, cleaning may be accomplished very effectively.

Drinking water supplies in Ireland are predominantly sourced from surface waters or groundwaters influenced by surface water. In recent reports on “The Provision and Quality of Drinking Water in Ireland” the Environmental Protection Agency (EPA) found that 81.6% originates from surface water (i.e. rivers and lakes) with the remainder originating from groundwater (10.3%) and springs (8%). Source waters, susceptible to surface contamination, particularly surface waters and groundwater and spring sources contain micro-organisms such as bacteria, viruses and protozoan parasites (e.g. Cryptosporidium) which can present a risk to human health if not effectively treated and disinfected. Since 2008 the EPA has set out as its policy that the most effective means of consistently ensuring the safety of a drinking water supply is through the use of a comprehensive risk assessment and risk management approach that encompasses all steps in water supply from catchment to consumer. The EPA has advised Water Service Authorities to implement the World Health Organisation (WHO) Water Safety Plan approach to risk assessment and risk management.

Meeting the goal of clean, safe drinking water requires a multi-barrier approach that includes: •Protecting source water from contamination, •Appropriately treating raw water, •And ensuring safe distribution of treated water to consumers’ taps.