Pesticides – yes or no?

We welcome the debate on the use of pesticides on the island, in particular glyphosate, and are supportive of both the expertise in HSE and the alternatives used by States Works.

Health issues

Some people have suggested Guernsey follows the example of the USA. It’s clear that the USA has a liberal attitude to all sorts of things, from gun ownership to pesticide use. While its environmental protection authority does approve glyphosate, there are thousands of court cases in the USA where previous users have established a link with the use of Roundup and cancer and have been awarded $millions in damages. Perhaps a better example is the EU which says glyphosate is a “probable carcinogen” and is reviewing its future use. Its general use has been banned or dropped in many places around the world including France, Belgium, much of Canada, Bath, Bristol, Brighton, Cambridge, Guildford, and Reading to name but a few.

Safety tests

You might ask hasn’t glyphosate been tested before being sold? And the answer is similar to the situation with DDT and all other pesticides- it was tested in the lab, and for its overall toxicity, but not in every situation in which it’s used. It takes time for all the effects of any pesticide to be uncovered, and that is certainly true of glyphosate. Aside from the public health issues, it has been directly shown to harm many of our vital pollinating insects. These “sub-lethal” effects have very recently been shown again in bumblebees, where exposure to glyphosate affects the ability of the bees to manage temperatures in the nest. The evidence around these effects continues to build and the volume of beneficial insects in Europe and UK declines. And remember, if we lose our pollinators, we lose our wild flowers, and much of our food, never mind our gardens.


There are plenty of alternatives, from the mechanical means (hoes, strimming, pulling, cutting, mowing), to leaving the plants flower and appreciating their beauty, to organic chemicals. It is possible to be pesticide-free and still keep our formal areas formal, but take a natural approach and support wildflowers wherever they grow.

What about other pesticides?

Supporting nature is definitely the Guernsey way, so perhaps the question we should be asking is “should we allow glyphosate or any other pesticides to be used at all?” The answer in France is no, they have banned pesticides for cosmetic purposes, for domestic use and in sensitive areas including public parks, gardens, and playgrounds. We are in Guernsey, in many ways even more vulnerable to contamination by pesticides, as our drinking water comes from rainfall and the recent ban by HSE seeks to address this.

States of Guernsey government questions pesticide use

dandelions with pesticide sign

The States of Guernsey Assembly recently brought up pesticides in their debate,

Deputy Al Brouard, President of Health and Social Services was the first to raise a question:

“There are concerns about the use of pesticides locally and weedkillers etc…could the Committee just consider publishing a list of alternatives for farmers and households? I think I’ve heard things like boiling water, vinegar, obviously manual extraction, natural mulches, but I think it would be helpful, I know Guernsey Water put out their concerns, but it would be helpful to have the other side of the coin, is what we can do instead that would help householders.”

The response from Deputy Lindsay De Sausmarez, President of Environment and Infrastructure committee gave a good overview of where Guernsey is currently at:

“Yes, absolutely, we are working with the Pollinator Project and Guernsey Water on exactly that and Deputy Brouard has just saved my voice a little bit because he has listed some really great alternatives and the ones I would have used. And we are walking the walk in that respect, States Works have barely used any glyphosate, certainly since 2020. There are occasions where there really aren’t workable alternatives or not pragmatic ones, for example in the control of noxious weeds such as Japanese Knotweed and the treatment of Asian Hornets is another area where we have to use chemicals but that’s very, very carefully controlled. We have taken various steps in terms internally but we are working with the Pollinator Project in particular and a big part of that includes a communications plan which we are working with them hand-in-hand on to get those very important messages out into the public domain. Its not just about alternative products, it’s also about alternative management techniques.

Recategorising weeds into wild flowers is one of my favourite methods, that can be done and it is a reasonable approach.

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.