Pesticides – Guernsey’s pesticide use wastes 250 million litres of water annually

Guernsey Water warns of water use restrictions or significant bill hikes in future if pesticide use (including weedkillers) are used at the current rate).

The water utility has confirmed that the Vale Pond water catchment, which used to provide around 250 million litres of water each year can no longer be collected due to the pesticide levels. Both commercial application and domestic use in gardening are thought to be contributing.

Margaret McGuinness, Water Quality Risk Manager at Guernsey Water, said: “With our climate warming up and more severe droughts predicted for the future, the fact we are currently unable to collect what would equate to around 19 days’ worth of water during drought for the Island is significant and concerning.”

65% increase in pesticides in 3 years 

The problem does not just affect the Vale Pond water catchment area. From 2019 to 2021 regular water quality sampling indicates that there has been an estimated 65% increase in pesticide concentrations in streams across the island.

“If these levels continue, we will be more likely to need water restrictions such as hose pipe bans during periods of drought,” said Mrs McGuinness. If the use of pesticides and weedkiller continues to increase the alternative would be to provide more water treatment, but this would require major investment and would also increase operational and maintenance costs. This could lead to a rise in customer bills.

“We are asking Islanders with some urgency to reconsider their use of pesticides and weedkiller and look to alternatives for the benefit of the island’s vital water resources and environment. Otherwise, unfortunately it could be a case of spray now, pay later,” said Mrs McGuinness.