Minister allows pesticide in water to remain over the limit

Monday 03 February 2020

The Environment Minister has allowed levels of the chemical Oxadixyl to exceed the legal limit in island mains water until 2025.

The dispensation was granted following an application from Jersey Water.

A similar dispensation, which set the maximum concentration of Oxadixyl - a pesticide used on potato crops until around 2003 - in the water at of 0.3 μg/l, was granted in 2016 for a period of three years.

The pesticide was found in untreated water samples in 2016 after Jersey Water changed the laboratory it uses for testing water samples.

While the levels were low, they contravened Jersey Law and Jersey Water applied to Deputy Steve Luce, the then-Environment Minister, for the dispensation so that, if Oxadixyl levels at Val de la Mare were to rise due to less rainfall, it could use the reservoir without breaking the law. 

The dispensation expired on 17 June 2019, after which the maximum authorised concentration of Oxadixyl in the water returned to its normal level at 0.1 μg/l. 

However, Jersey Water wrote to Deputy John Young, the current Environment Minister, on 14 January, for a new dispensation this time asking for the limit to be set at 0.2 μg/l, “based on their operational and monitoring data”.

In addition, they requested that the calculation for the total pesticides limit of 0.5 μg/l should not include any concentration of Oxadixyl whilst it is within the proposed dispensation limit of 0.2 μg/l. 

The Minister granted the application after contacting the Medical Officer of Health and the Minister for Health and Social Services, Deputy Richard Renouf, neither of whom opposed it.

The Ministerial Decision noted that Jersey Water would in practice continue to work to comply with the 0.1 μg/l limits “wherever practical”, but that this would be balanced with the need to manage water resources.

“Oxadixyl is a chemical which has not been used on Jersey for many years,” a government spokesperson explained.

“Work being carried out by Jersey Water is removing more of this and other chemicals from drinking water. Further works are planned to further reduce these levels. The levels involved are many times lower than the health-related level. Alternative methods to reduce the level (such as blending with water from the desalination plant) would be costly.”

As part of the dispensation, the Minister has imposed a series of conditions on Jersey Water. One of them means the company will have to contact the regulator if the level of Oxadixyl exceeds 0.1 μg/l to explain why it has happened and what action will be taken to ensure it does not go over 0.2 μg/l.

They will also be required to look into treatment options for the chemical and update the government on the development of a treatment process on a quarterly basis. Similar conditions were imposed by Deputy Luce in 2016.

Deputy Young has also stipulated that Jersey Water must keep the government informed on the progress and commissioning of the desalination plant, and the planned reservoir by-passes at Val de la Mare and Queen’s Valley.