Post a comment on the text below
3.4. data availability, gaps and uncertainties
Waterbase – Water Quality database includes the largest volume of concentration measurement data available from the European Environment Agency, covering about 180 different pesticides. Data include single measurement (so called “disaggregated”) data and aggregated data (including yearly mean, minimum, maximum and limit of quantification [LOQ] of pesticide concentrations).
The most prominent uncertainties in the Waterbase – Water Quality dataset are inconsistent reporting of limit of quantification (LOQ) values and inconsistent time series of the data from individual monitoring sites. Due to different requirements of European reporting, the LOQ has been reported either as flags or different values (inconsistent reporting of full LOQ values vs half-LOQ values according to the requirements of the European water quality directives, e.g. Directive 2009/90/EC), and in some cases no data regarding the LOQ is available for a record at all (see also section 3.1.1.3). This increases uncertainty in determining measurements that are below LOQ, needed for analyses such as EQS exceedance. Also, LOQ values that were indeed reported vary within the substance, in various cases within the country and year as well. Another inconsistency lies in reporting of the data from the same monitoring sites through time, which would compose consistent time series of comparable data. Instead, the data for many monitoring sites were not reported for more than a few years, which disperses spatial and temporal coverage of the dataset and makes trend analysis less credible.
You cannot post comments to this consultation because you are not authenticated. Please log in.
Previous comments
Another uncertainty is the potential mismatch between substances applied and substances monitored in a certain area, unless there is some way for aligning this.
In principle, we agree with the statement about lack of data over multiple years, particularly for groundwater data. However, any temporal trend data in surface water will only be credible in rather big water bodies, where input are coming from a rather large and diverse watershed. The situation in smaller water bodies is much more dynamic over a single year than it is across several year, therefore making a long-term analysis rather pointless.
HU:
In part 3.4 data uncertainties are discussed, Hungary has reported all disaggregated values according to Directive 2009/90/EC.