Why are herbicides being used at the airport? – De Lisle

The facility was cut from the water supply chain after samples taken last month from streams and the water treatment plant showed abnormally high levels of two herbicides – MCPA and Mecoprop.

They were within legal UK limits, but a decision was made to sever supply from the reservoir while Guernsey Water investigated. Another sample at Kings Mills was above UK guidelines, but not considered a significant health risk.

Deputy David De Lisle has submitted written questions to the States Trading Supervisory Board which its president, Deputy Peter Ferbrache, is expected to answer at next week’s States meeting.

Guernsey Water water quality risk manager Margaret McGuinness said: ‘Until results are received and we are able to assess whether the chemicals in St Saviour’s Reservoir have fallen to an acceptable level, the reservoir will continue to remain isolated from public supply.

‘We are continuing to maintain water supplies from other reservoirs whilst St Saviour’s Reservoir is off supply, and we expect this will be a short-term arrangement.’

STSB is responsible for the management, operation and maintenance of Guernsey Water and the Guernsey Airport.

Deputy David De Lisle said Mecoprop was commonly used to control a variety of weeds and was very toxic to aquatic life with long lasting effects.

It was also associated with human cancer of soft tissues and non-Hodgkin’s lymphoma along with kidney failure.

MCPA was a pesticide compound that was moderately toxic to wildfowl and slightly toxic to freshwater fish such as trout.

It is used to control annual and perennial weeds including thistle and dock.

As the chemicals are toxic, he wants to know what range of levels of MCPA and Mecoprop are in the raw and treated water and what the UK permitted levels are.

The chemical spill may have been caused by the application of approved herbicides for weed control under an established part of the Wildlife and Habitat Management Programme at the airport.

‘Can a copy of the Airport management programme be obtained, and who is managing it, applying the chemicals and paying for it?’ said Deputy De Lisle.

‘Why are these toxic chemicals being applied when alternatives are available and, given the significant risk to human health and wildlife, would the States’ Trading Supervisory Board encourage the Airport authority to stop applying these chemicals and instead use land management techniques other than chemical controls?’