The departments of Water and Sanitation (DWS) and Forestry, Fisheries and the Environment (DFFE) are reviewing complaints and concerns in the public domain over the use of chemicals as part of a programme to eliminate water lettuce in the Vaal river.

In a joint statement, Forestry, Fisheries and the Environment Minister Barbara Creecy and Water and Sanitation Minister Senzo Mchunu said that they noted public concerns over the use of glyphosate, the chemical used to clear alien invasive plants from the Vaal river in a programme led by Rand Water.

This followed Rand Water’s announcement last week that it is taking a three-pronged integrated approach, including physical removal, to clear the invasive species currently overwhelming the Vaal Barrage.

Rand Water, after being approached by communities, has been working with Rhodes University and various technical experts, as well as local communities, to develop options to mitigate the challenge.

The integrated approach combined the physical removal, chemical control and biological control and all the necessary authorisations had been obtained, said Rand Water corporate services GM Mbuyiswa Makhubela during a small ceremonial mrking the release of the biological agents, namely weevils and hoppers, on February 15 at Stonehaven on the Vaal, in Vanderbijlpark, prior to wider release.

Rand Water released the first batch of weevils and hoppers as biocontrol agents to start eliminating the invasive water lettuce in the Vaal river, following the physical removal of the plants by communities and the spraying of specifically formulated and DWS- and DFFE-approved chemical controls, at very controlled, specific, sub-lethal dosage rates.

While biological control, such as the weevils and hoppers, can control the majority of these floating aquatic species over the long term, there is a need to get rid of a large majority of these plants as quickly as possible, which is where the manual removal or the chemical treatment play a significant role.

Rand Water environmental services manager Dr Lesley Hoy previously told Engineering News Online that the use of the chemicals received all the required authorisations and the teams had followed all protocols and compliance within the guidelines provided to ensure that all risks related to physical removal, chemical control and the use of biological agents were mitigated.

The two Ministers and other relevant parties met following the complaints in the public domain and agreed to determine whether the clearing methods followed were in line with the regulatory environment and to devise a future plan that ensured that the clearing of the alien invasive plants was done in a manner that posed no harm to the environment, the departments said in a statement.

Once that process is concluded, the departments will issue a further statement on the way forward.