Risk Assessment Pesticide Information Database - RAPID support with Pesticide Chemicals

Many initiatives have been implemented over recent decades both to refine pesticide application processes and usage to reduce the risk of pesticides entering environmental waters. Whilst these efforts have considerably reduced pesticide concentrations in river and ground waters, pesticides are still present in source waters with levels still requiring treatment for drinking water production. How can we better understand pesticide usage across our river catchments? How can this information be used to reduce this contaminant at source, or to inform site specific water treatment plans for continued environmental and public health protection.

At WRc we focused on the risks that pesticides used in agriculture pose to drinking water sources. Knowledge of pesticides used in the source water catchments is fundamental to drinking water safety plans which assess and manage risk across the source to tap supply system. Ongoing work in catchments and farmers seeks to reduce pesticide runoff providing some level of preventative action to minimise this risk. Water sources are regularly monitored for pesticides, the data is used to assess source water risk and the efficacy of treatment control measures to ensure water supplied meets the standards outlined in the Water Supply (Water Quality) Regulations and is safe for human consumption.

Before water is abstracted it will most likely have contact with farmland, so we rely on the system of pesticides approvals and product authorisations to manage the risks of what chemicals are allowed to be used on specific crops. This is a highly regulated area and reduces the risk to the environment, drinking water and minimises residuals pesticide concentrations in food - not forgetting the importance of health and safety practices for farm workers. Environment pesticide use should be targeted and Integrated Pest Management schemes from the Voluntary Initiative and LEAF support growers and farmers in how to keep pesticides on the targeted crop and out of the water environment.

How do some chemicals continue to get into rivers or groundwater? Upstream of a water source the watershed / catchment soils and aquifers act as a store, release rates are driven by how the chemicals behave and daily weather patterns. Are these chemicals easily dissolved in water or do they stay bound to the soils? Do they break down in sunlight or persist? During dry periods there is a larger store of chemicals these are then washed off during wet periods. Some areas of the UK have recently experienced weeks of dry weather then a deluge of rain causes polluted waters to run off into rivers.

There are funding limits for the monitoring needed to detect usually very low concentrations of potentially hundreds of contaminants.

RAPID (Risk Assessment Pesticide Information Database) is an online tool for reviewing risks from the actives reported to have been used on crops for each region of the UK. The usage statistics combined with chemical properties indicates which pesticides may be detected in surface and groundwaters. This provides information on which pesticides to monitor so that actions can be taken at source and with treatment plans to protect the environment and public health.