The nitrate concentration of groundwater is dependent on the depth from where water is taken, precipitation in that area, and ecology of the regions. So, to calibrate, you better take ecological regions like Palearctic, Nearctic, Neo-tropical, Ethiopian, Oriental, and Australian regions rather than the countries as you think.

http://waternet.ua/map/ can give information about nitrates and other pollutants in drinking water. But it is in Ukrainian.

Hi,

Groundwater pollution by nitrates

Nitrates are the most problematic macropollutants in groundwater. If they exist naturally in the groundwater in small quantities, their concentration above 10 mg / l, attests to anthropogenic pollution.

Agricultural fertilization and to a lesser extent urban, domestic and industrial discharges are the causes of the high levels measured in the aquifers. However, the latter are not all equal in the face of these environmental pressures. Tablecloths under thick clay cover, called captive sheets, are protected from infiltration and their nitrate contents are kept at low levels. They can benefit from denitrification phenomena, favored in these confined environments.

Average concentration of nitrates in groundwater

The highest levels of nitrates are found mainly in the northern half of France, mainly in northern Brittany, north of the Nouvelle-Aquitaine region and in the Paris Basin. The aquifers concerned cover 5.4% of the territory, 1.2% of which have levels above the threshold for drinking water.

The presence of nitrates at concentrations between 25 and 40 mg / l affects 37% of the surface of the metropolis, delimited mostly by the middle mountain. On the other hand, 27% of France's surface area, consisting mainly of the high mountains and the territories with sandy-clay soil, show a virtual absence of pollution.

To do this, we generally use maps following the following methodology:

Methodology

The average per hydrogeological unit is calculated from the data from the monitoring networks of the Water Framework Directive (WFD): surveillance monitoring network (RCS) and operational control network (OCR).

While the purpose of the surveillance control network is to provide a heritage image of groundwater contamination, the operational control network aims to monitor water points in particularly contaminated areas. The latter has been enriched by numerous monitoring stations, particularly in 2013 and 2014 in the Artois-Picardie and Rhône Méditerranée Corse basin.

Classes of concentrations:

- 10 mg / l is the maximum natural nitrate content of a water table, without anthropogenic pollution. The other thresholds are standardized by the various European directives:

- 25 mg / l as guide value,

- 40 mg / l as the action threshold,

- 50 mg / l as the maximum threshold for good groundwater status, and also the maximum allowable level for water intended for human consumption.

Hi

I think you have our data already, but if not let then let me know.

alwyn

Thanks Alwyn,

I will talk to you later regarding data and comments.

Cheers,

Lei

Hi Lei,

You may find groundwater nitrate concentrations for years 2013, 2014 and 2015 for Greek aquifers (around 1375 sample points) in http://nmwn.ypeka.gr/ (in Greek).

Please let know if you are interested for a potential collaboration regarding the processing of these data.

Kind regards

Charis