20 March 2002

Synthesis Paper

Article 17 WFD - Groundwater Daughter Directive

built on Issue Paper 6th November 2001

Introduction

This paper is an attempt to sum up the current discussion for the future Groundwater Daughter Directive according to Article 17 of the Water Framework Directive. The paper is largely built on the issue paper of the Commission (status 06th November) integrating the results of the Drafting Groups, which were established in addition to the Expert Advisory Forum on Groundwater in order to discuss certain questions in more depth. The Drafting Groups came together for broad discussions in January and March 2002 and recorded the group results in final papers, which are enclosed in the Annex.

The present paper should be understood as a synthesis of an open discussion on different conceptual approaches based on the analysis of the different pollution problems in European groundwater and should not be taken as a final Commission position. It should serve as a sound technical and conceptual basis before starting the actual process of drafting a legislative Proposal.

Legal basis and linkages to existing legislation

The main principles for the future groundwater protection policy are already set out by the Water Framework Directive (WFD). The principals of “prevent and limit” pollution, the "no-deterioration clause", the prohibition of direct discharges and the link to the objectives of associated surface waters and ecosystems are utmost importance. However, the operational provisions are not complete and have to be analysed with regard to possible shortcomings.

One approach to develop the Daughter Directive could be to limit on the minimum requirements set out in Article 17(2) WFD. Given the concern of the European Parliament during the conciliation, as well as the view of the Water Directors in the Ghent Meeting and the broad support of the First Expert Advisory Forum on Groundwater a wider approach seems to be more appropriate.

The terminology "Daughter Directive" is misleading, because it suggests that there will be a hierarchy between this specific groundwater directive and the Water Framework Directive. The future Groundwater Directive is a separate, independent piece of legislation based on the Treaty. However the Daughter Directive is not supposed to set new objectives for groundwater but to underpin – where necessary - the basic provisions set out in the WFD, to complete the regulations and make the requirements operational.

The basic provisions of the WFD concerning groundwater quality, which have to be considered whilst developing the proposal of a Daughter Directive on groundwater refer to Article 4, 7 and 11, 17 and Annex V of WFD:

  • Member States shall implement the measures necessary to prevent or limit the input of pollutants into groundwater and to prevent deterioration of the status of all bodies of groundwater.
  • Member States shall also protect, enhance and restore all bodies of groundwater with the aim of achieving good status by 2015. Good groundwater chemical status is considered when the chemical composition of the groundwater body is such that the concentration of pollutants do not exhibit the effects of saline or other intrusions, and do not exceed the quality standards applicable under other Community legislation (e.g. Nitrate Directive and Directive concerning the placing of plant protection products on the market) in accordance with Article 17. The chemical compound of the groundwater body must not be such that would result in failure to achieve the good chemical or ecological status in associated surface waters nor any significant damage to terrestrial ecosystems depending on the groundwater body.
  • Member States shall implement the measures necessary to reverse any significant and sustained upward trends in the concentration of any pollutant resulting from the impact of human activity in order to progressively reduce pollution of groundwater. To concrete this the Commission shall propose by the end of 2002 measures to prevent and control groundwater pollution. These measures shall include criteria for assessing good groundwater status, criteria for the identification of significant and sustained upward trends and for the definition of starting points for trend reversals. In the absence of such criteria at Community or Member State level, starting point for trend reversal should be maximum 75% of the quality standards set out in existing Community legislation.
  • Member States shall ensure the necessary protection for bodies of water used for the abstraction of water intended for (existing or future) human consumption and they shall take measures to safeguard water quality in order to reduce the level of purification treatment required for the protection of drinking water.
  • Member States have to adopt a set of basic measures that shall include a prohibition of direct discharges of pollutants into groundwater.

Case analysis as a basis for the conceptual approach

Current reports and case studies emphasise, that there is a serious threat on the European ground water. The pollution is caused by both diffuse sources, often on large areas, as well as point sources, where the pollution is very local, but on the other hand quite significant. Huge areas are influenced by nitrogen fertilisers and by pesticides. Other important impacts on groundwater around Europe are chloride, acidification, chlorinated hydrocarbons and hydrocarbons, heavy metals.

In order to structure the discussion on possible regulations of the Daughter Directive the following three different cases are distinguished and key issues addressed by the drafting groups:

  • Case I / Group I: Unpolluted groundwater body with pollution pressure from point or diffuse sources
  • Case II /Group II: Polluted groundwater body with continues pressure from diffuse pollution
  • Case III / Group III: Polluted groundwater body with continued pressure from a point source (contaminated sites).

Furthermore two additional groups had been working on following key issues:

  • Group IV: cross cutting issue on surface water groundwater interaction
  • Group V: statistical methods for data aggregation and trend/trend reversal

PressurePressure

The purpose of the scheme is to focus the discussion on the three different cases of groundwater pollution and to analyse for each case

  • Relevant requirements in the WFD
  • possible approaches to deal with the shortcomings

The green (upper) boxes in the scheme refer to existing provisions of the WFD while the lowest (red) boxes are looking at possible approaches to tackle with shortcomings. In the following chapters, each case is elaborated separately.

Unpolluted groundwater body with pollution pressure

Shortcomings

Although the WFD provides protection mechanisms for unpolluted groundwater, it does not provide a definition of ‘unpolluted groundwater’ or ‘groundwater in a natural status’. So reference conditions, in order to assess the current deviation are missing. Consequently an uncertainty remains on the target for the measures to implement the no- deterioration clause and the provision on pollution prevention for groundwater bodies that are pristine or largely unaffected by human activity.

Proposed Approaches

There is a general agreement that groundwater bodies, whose chemical composition is currently pristine or near pristine should remain so. Suitable measures should be put in place to ensure protection. Appropriate approaches, which are not necessarily mutually exclusive, are the following:

  • strengthening the prevent and limit clause through emission control (preventative measures). This can be done by e.g. drawing up a core "prevent substances list" on an Europe wide basis.
  • Clarification of the no deterioration clause. (Whilst interpret it as no-deterioration from the current status (status quo) - ie no deterioration within a class - it would effectively protect all groundwater bodies which are unaffected).
  • Establishing a new class for high chemical status (natural groundwater, which has been largely unaffected by anthropogenic pollution). It needs to be defined in relation to background conditions as result of the characterisation process according Annex II.2 WFD) and will act as benchmark, showing the deviation from pristine conditions. The high chemical status is not foreseen as restoration target.
  • Establishing protection zones for pristine waters as additional protective measure.

Polluted groundwater body with pressure from diffuse pollution

Shortcomings

The definition of the good groundwater status in Annex V, WFD is very limited with view to pollution of groundwater by substances other than nitrates and pesticides. Groundwater bodies could be polluted by quite a number of substances and still comply with that definition of good status.

Possible approaches

There is a general agreement that other substances than nitrate and pesticides cause groundwater pollution problems of EU-wide relevance. Besides nitrate and pesticides (and relevant metabolites) parameters indicating diffuse pollution are e.g. phosphorus, parameters of acidification (pH and as results of leaching e.g. heavy metals) atmospheric deposition (e.g. VOC, MTBE), saline intrusion (chloride) and pathogens. Diffuse pollution may also cause "secondary effects". For example denitrification in the subsoil leads to increased hardness of groundwater (increase of sulphate).

For the purpose of considering groundwater management it may be helpful to distinguish groups of substances in at least:

(a)Synthetic (man-made) substances not found in the natural environment

(b)Naturally occurring substances

Different approaches could be used to derive quality standards to underpin the "good status" for different substances or substance groups:

(1)To set standards for a limited number of substances might be needed to make the status requirements operational

(2)To apply common standards (from common EU-legislation) uniformly across Europe. Example of parameter: pesticides.

(3)To apply risk or receptor based standards for all pollution parameters, derived from the existing definition in Annex V reflecting the relation between groundwater and surface water. Example of parameter: heavy metals.

(4)To apply a combined approach where common standards are combined with a risk or receptor based approach. So that certain standards could be overlain - where necessary by (tighter) standards appropriate to meet other objectives. The stricter value has to be applied. Example of parameter: nitrates

Action values are regarded as unnecessary, because identifying any statistically significant trend (required in WFD and drawn up by CIS-WG 2.8) gives a high degree of certainty that there is a real pollution threat. In this light any upward trend should be reversed, regardless of the value for the given pollutant.

Specific measures to prevent and control groundwater pollution should be elaborated in a guidance document.

Polluted groundwater body with continues pressure from a point source

Shortcomings:

The WFD requires measures in order to avoid further emissions from point sources into the groundwater and to take clean up measures for the polluted groundwater, but does not set any restoration targets for substances, that are often emitted from e.g. contaminated sites. Moreover, the definition of good status does not provide any target values for substances with regard to point sources.

Furthermore the "good quality status" according WFD is related to the entire groundwater bodies whilst point sources - even if there are many in number - normally affect a very limited area within a groundwater body.

Possible approaches:

Most of the pollution problems from point sources are of very local character, e.g. contaminated sites, industrial sites, landfills, accidents/chemical spillage or leaks from tanks. Point source pollution typically results in the formation of a plume of contaminated ground water, which is often shorter than 500 meters. The problems differ widely concerning substances, geographical extension, and intensity of pollution. That is why setting European-wide restoration targets for groundwater pollution caused by point sources is regarded as inappropriate and technically not robust.

To tackle with point source pollution new common strategies and a methodology of acting should be set out containing the following principles. (The detailed working programmes should be elaborated on a local level):

  • Distinction between new and historical contamination: new point sources are subject to pollution prevention and must be dealt with in any case and as swift as possible after detection. Whether historical point sources must be remediated or not must follow from a site-specific risk-based decision taking into account all possible receptors.
  • Appropriate measures have to be required, in order to avoid further pollution. As a first step the "plume behaviour" has to be assessed. (For example expanding plumes are not accepted within a certain time frame.)

Integration of surface water and groundwater objectives

Objectives for groundwater and surface waters are broadly similar, but are subject to differing conditions and limitations. Surface water standards may simply be inappropriate to groundwater, whilst certain groundwater parameters have no surface water equivalents.

In general emission standards designed for surface water are inappropriate to the protection of groundwater. Attenuation in the unsaturated zone should continue to be taken into consideration in assessing the impact of pollutants.

Furthermore it is the flux (the concentration of pollutants and volume of water) exchanged between surface water and groundwater and its share in the overall surface water load, which is important in determining standards for protection of surface waters, rather than the concentration of pollutants.

A first estimate of probability that fluxes from groundwater would result in failure to achieve the environmental objectives for associated surface water produces:

  • Phosphates, nitrites, PAH, hydrocarbons, aromates
    and volatile chlorinated hydrocarbons negligible
  • Nitrates, pH, pesticides:(extremley) variable
  • Heavy metals, Ammonia, chloride low

Thus the preliminary conclusions are (may need further broad discussions based on experiences):

  • Fluxes from groundwater are in most cases not responsible for failures in achieving the objectives in associated surface water, but may contribute to such failures in an extent, which is highly depending on the specific parameter.
  • An application of more stringent quality objectives of surface waters to groundwater would be justified only for rare exemptions tailor made to the local situation.

Statistical aspects of groundwater assessment

The results of the group dealing with the statistical aspects of the identification of pollution trends and aggregation of monitoring data are strongly linked with the work of CIS -WG 2.7 and the future paper on "Identifying Bodies of Water" of the Commission. This issue is therefore not finally discussed in the current paper.

The main agreement referring to the discussion on the Daughter Directive, that the areas at risk within the groundwater bodies should be identifiable. Differences in status of a groundwater body should not be hidden away by data aggregation methods.

Timetable

Conceptual phase / Drafting phase
Nov
2001 / April
2002 / June
2002 / Nov
2002
Water Directors meeting Gent 8th Nov. 5,
Objective: Agree on the procedure and conceptual approach / X
First EAF meeting 23rd Nov.
Objective: Get agreemnt on the conceptual based approach / X
Study and discussion on practices used in MS and case studies (drafting groups) / X / X / X / X / X
Second EAF meeting
Objective: Setting the final concept for the daughter legislation / X
First outline of the legislative Proposal
Objective: preparation for the Water Director meeting in June. / X
Economic study based on the concept / X / X / X / X / X / X / X
Water Directors meeting in Spain (June)
Objective: Get first decisions on the outline of the legisl. Proposal / X
Third EAF meeting June
Objective: Adjustments of the first outline of the legislative Proposal / X
Forth EAF meeting Oct.
Objective: Final adjustment of the first outline of the legislative Proposal / X
Proposal for daughter Directive / X

ANNEX

Final Papers of Drafting Groups I to V

1