Drivers of Monitoring Activities: Pesticides in the Environment, Now and in the Future

Adrian Terry - Cambridge Environmental Assessments

Introduction

Ultimately, the intensity and range of monitoring activities undertaken will be determined by Society. It is clear that concern for the Environment has grown substantially over the last twenty years and continues to grow. The more affluent a society becomes the more concern there is for the quality of life and increasingly the state of the Environment is being considered as a key indicator of this. Pesticides have been an obvious target for monitoring activities, given that they are released directly into the Environment. Consequently, monitoring for the presence of some pesticides in the environment is undertaken by many different organisations across the EU. This translates almost exclusively into monitoring for substances in the aquatic environment, at this point in time. Most of this activity is carried out by statutory regulatory organisations, largely in response to EU directives. The consequences of the arrival of the Water Framework Directive (WFD) in 2000 will eventually replace many of the current legislative drivers.

Now

Many monitoring programs have been established for a number of years as a result of the EU Directives which included requirements to monitor water (drinking water, groundwater and surface water). Different concerns are associated with the different water categories.

Concern for surface waters has been driven by potential adverse effects of substances on the ecological status of rivers, lakes and reservoirs. The Dangerous Substances Directive 76/464/EEC has been the main driver for monitoring of surface water, given the requirement to eliminate or reduce the contamination of surface waters by list I and list II substances. Trigger levels (Environmental Quality Standards; EQS's) have been set via a number of initiatives including daughter Directives of 76/464/EEC and nationally. They are considered to be protective towards potentially exposed organisms and are, therefore, based on individual substances' toxicities. However, the range of substances for which monitoring is mandatory is very limited. Some EU countries (e.g. UK) include a much wider range of pesticides in their national monitoring programme, additional analytical targets being chosen according to more local concerns depending on usage and known exposure routes.

Further monitoring has been instituted in more recent years in response to the imminent requirements of the Water Framework Directive, which will replace current monitoring requirements significantly, broadening the range of substances that may need to be monitored for.

Protection of groundwater resources, where they are a source of drinking water, is currently mandated in the EU Directive 80/68/EEC. The aim of this legislation is to protect exploitable groundwater sources of drinking water from direct and indirect discharge of dangerous substances, which are defined in the Dangerous Substances Directive 76/464/EEC. The defined dangerous substances are divided into list I and list II substances, according to their toxicity, with list I substances being the more problematical and subject to non-approval (examples of pesticides being aldrin, dieldrin, endrin, DDT). List II substances are of concern, but many have not been banned as yet (examples of pesticides being bentazone, endosulfan, fenitrothion, trifluralin). According to the legislation, monitoring groundwater for these substances is only required where authorisation to discharge these has been sought. However, several EU countries (e.g. UK and Denmark) have national monitoring sites where groundwater is regularly monitored for the presence of these substances and other pesticides.

The 0.1 µg/L trigger is considered important given that groundwater resources could be used for the provision of drinking water, as are the relevant EQS values for the protection of wildlife. Non-statutory monitoring of groundwater resources is also undertaken by some water provider companies. In this case the data is collected to aid planning with respect to the provision of drinking water which will not exceed the pesticide content triggers (the data helps inform treatment requirements and necessities to blend the source or exclude it from the drinking water network). This data is rarely made public.

Directive 80/68/EEC is due to be replaced by the Water Framework Daughter Directive on Groundwater [commission proposal COM(2003)550], which applies to all groundwater, irrespective of its possible use for the provision of drinking water.

For drinking water, there is a direct concern with respect to adverse effects on human health due to the presence of pesticides. The first EU Directive (80/778/EEC) set a pseudo-zero value of <0.1 µg/L as a permissible level for individual pesticides and <0.5 µg/L for total pesticide content. These triggers (which have been retained in the replacement Drinking Water Directive 98/83/EC) were not based on toxicity considerations (which would have led to different levels depending on the toxicity of the pesticide), but rather indicated a desire for 'no residues' of pesticides in drinking water. However, 98/83/EC did introduce a lower trigger value of 0.03 µg/L for a small number of very toxic substances (aldrin, dieldrin, heptachlor and heptachlor epoxide). Regular quality monitoring is required to check compliance with these standards at the point where the water is made available to the consumer. The analytical targets are not defined by the Directive, but are decided by the monitoring authority (which may be the relevant water provider) based on an understanding of the local usage of pesticides and the risk to drinking water posed by that use. In effect, the monitoring authority is required to conduct a risk assessment which takes into account the usage of the substance, the local soils and the local climate in order to select the analytical targets, but the legislation does not define this process.

In the Future

EU Directive 2000/60/EC (the Water Framework Directive: WFD) was to be transposed into national legislation during 2003. It sets out to be inclusive (with respect to water in the EU) and far reaching, with the aim of improving and protecting the status of all inland waters, transitional waters, coastal waters and groundwater. As such it replaces many of the legislative instruments that have informed monitoring in EU countries and changes the way that analytical targets are to be selected.

Water resources have been assigned to River Basin Districts (RBD) which will be subject to River Basin Management Plans that set out how the quality objectives for all the water bodies within each river basin are to be achieved. The approach is both integrated (with respect to water body type) and co-ordinated. A challenging timetable has been set out stretching to 2027 which should result in the improvement in status of all water in the EU. With respect to monitoring for pesticides, there are a number of different drivers within the WFD, depending on the water body type, but a comprehensive monitoring network is required to be established by the end of 2006.

Water bodies within RBD's will need to be examined and the factors that are, or threaten, to adversely impact on their status must be identified and a program of action arrived at to prevent or reverse the impact. With respect to pesticides, slightly different emphasis applies depending on the water body type.

For surface waters, the ecological status and the chemical status must be monitored. The chemical status relates to the presence of a set of EU-wide defined substances regarded as hazardous. This is similar to the current list I and list II approach, except that there has been a detailed procedure outlined for determining which substances should be regarded as either Priority Substances (where discharges, emissions and losses must be subject to reduction) or Priority Hazardous Substances (where discharges, emissions and losses must cease over a twenty year period), and a provision made to review this list. Surveillance monitoring is likely to be required to ascertain levels of these Priority substances.

Ecological status will be more difficult to monitor. An analysis will be required for each water body (or of a representative water body) to determine if the presence of a pesticide is likely and might lead to an adverse effect which would impact on the ecological status. It might then be deemed necessary to monitor directly for the presence of this pesticide (compared to the level of concern, which might be an EQS value for a specific water body) or, perhaps, to monitor for the possible biological/ecological impact. The latter might, in turn, result in the need for specific monitoring for the pesticide if an adverse ecological impact is detected. This approach is likely to lead to different pesticide monitoring requirements for different locations and is effectively a move away from standardised monitoring towards a more risk based approach. It does seem likely, however, that the requirement to consider all water bodies will result overall in more monitoring for pesticides in surface water being undertaken.

The situation for groundwater will be less complicated. Only monitoring for chemical status will be required (although this will apply to all groundwater sources) and not for ecological status. The guiding principle will be to protect groundwater from all chemical contamination. There will be a prohibition on direct discharges to groundwater and a requirement to monitor groundwater so as to detect changes in chemical composition (so that contamination can be reversed). The selection of analytical targets will depend on the risk assessment process with respect to factors that might apply to the specified groundwater body. In addition, it will also be necessary to consider possible adverse effects (chemical or ecological) on any surface water bodies that the groundwater body is continuous with.

For drinking water, at the point of use, the trigger levels are not changed by the WFD. However, the water bodies which are the source of the drinking water are subject to the requirements set out by the WFD. As such, it is likely that the analytical targets at the point of use for drinking water will be determined by the evaluations carried out on the source water bodies rather than on a separate usage/vulnerability assessment by the drinking water provider.

Overall, it is worth bearing in mind that there might be many unforeseen consequences, with respect to chemical monitoring requirements, arising from the implementation of the WFD. Further, the legislation has been framed in such a way that activities can be implemented almost on a catchment by catchment basis.

Timetable for the Implementation of the Water Framework Directive

Year Issue
2000 Directive entered into force.
2003 Transposition into national legislation.

Identification of River Basin Districts and Authorities.
2004 Characterisation of river basins: pressures, impacts and economic analysis.
2006 Establishment of monitoring network.

Start of public consultation (at the latest).
2008 Present draft river basin management plans.
2009 Finalise river basin management plans including programme of measures.
2010 Introduce pricing policies.
2012 Make operational programmes of measures.
2013 Implementation of Groundwater Daughter Directive.
2015 Meet environmental objectives.
2021 First management cycle ends.
2027 Second management cycle ends, final deadline for meeting objectives.