Please note that the following report for groundwater contamination in Denmark indicates that Danish authorities have detected glyphosate and AMPA in Danish groundwater during 2000. This is worrying as Roundup Ready crops are touted as "environmentally friendly" based on Monsanto's claims about Roundup/glyphosate. AMPA is the metabolite of glyphosate. More GMOs with herbicide resistance would mean more of these posions in drinking water supplies.
Sincerely, Martin Frid Swedish Consumer Coalition
GROUNDWATER MONITORING IN DENMARK 2000
Groundwater monitoring in Denmark is based on information from groundwater monitoring areas, agricultural watersheds and water supply wells. As a whole they provide the most qualified information on groundwater chemistry and pollution at the national scale available.
61% of the line monitoring wells and 69% of the water supply wells contain no nitrate (< 1 mg/l nitrate). 24% of the monitoring screens have a nitrate concentration above the guide level for drinking water (25 mg/l) and 18% are above the maximum admissible concentration (MAC) for drinking water. Groundwater from 8.5% of the water supply wells have a nitrate concentration above the guide level for drinking water and 2% are above the MAC level. The low number of water supply wells with a high nitrate concentration is due to several reasons. Many wells with a high nitrate concentration have already been closed. Some water supply wells have long screened sections, and mixing of groundwater with and without nitrate occurs within the well. Finally, water supply wells are generally screened at a greater depth than monitoring wells.
The general opinion is still that the content of nitrate in the groundwater has not changed significantly since the approval of the Action Plan for the Aquatic Environment in 1987. However, this stable situation is not to be expected in future, as CFC age dating shows that the majority of the groundwater-containing nitrate was infiltrated before the approval of the Action Plan. As the majority of the drinking water supplied today comes from groundwater infiltrated since 1950, the first signs of effects of the beneficial impacts of the plan should be recognised within the next 10-year period.
Changes in the content of nitrate in shallow groundwater seem to indicate variations in the groundwater potential and thus changes in the groundwater flow regime, rather than direct changes in the load of nutrient on the groundwater. It is therefore difficult to determine weather a decrease in the content of nitrate is due to minor nutrient losses from farmland or due to variations in groundwater infiltration.
In many places, geologically dependent phosphorus content in groundwater above the MAC level (0.15 mg/l) in drinking water is found, especially in deep aquifers with marine sediments. However, rather high phosphorus values are normally not a problem to waterworks as phosphorus usually precipitates in the sand filters.
Salt water (chloride and sodium) in coastal zones is another limitation to drinking water supply. Furthermore road salting in wintertime may affect chloride and sodium concentration in shallow groundwater. Sulphate occurs in zones with sulphide minerals in the sediments and where lowering of the pizometric surface permits oxidation. Fluorine minerals are found in limestone where fluoride might be liberated to groundwater.
Nickel and Zinc are found in the groundwater in concentrations above the MAC level in 5% of the monitoring screens, respectively. Both are expected to be liberated from sulphide minerals in the sediments due to lowering of the pizometric surface. Normally, analyses for zinc are not included in the water supply well water control. In waterworks with ordinary water treatment it is expected that zinc and other inorganic trace elements will mainly be retained in the ochre sludge of the sand filters of the waterworks.
Aluminium is found in concentrations above the MAC level in 9% of the monitoring screens and in 22% of the water supply wells, especially in West Jutland where the pH values are low.
Among the organic micro pollutants the most commonly found chlorinated hydrocarbons, aromatic hydrocarbons and phenols are trichloromethane, benzene and phenol, which in are found in 9, 8 and 12% of the monitoring wells, respectively. In water supply wells the corresponding values are considerably lower.
Anion active detergents are omitted in this year report as quality assurance has detected significant errors in the received data. GEUS will try to set up the data in the coming year. The knowledge on the common occurrence of detergents in groundwater has not been improved.
During the last year some discussion has taken place on the detection of the five chemical elements/ element groups, MTBE, DBP, nonylphenol, 1,2-dibromethane and vinylchloride, that are new in the groundwater monitoring. Several difficulties on the development of qualified analysis methods have occurred. For now it must be summarised, that only MTBE, that is a part of high-octane petrol, is found in a number of wells, partly water supply wells and totally in 28 wells out of 164 investigated. The other four elements are only found in very few cases and they will be further treated when the data material is considerably improved.
Since 1993 pesticides and metabolites have been found in 34,7% of the investigated monitoring wells, and in 10.8% of the wells above the MAC of 0.1 mg/l for drinking water. Pesticides and metabolites influence half of the groundwater infiltrated within the last 25 years. Totally 32 pesticides and metabolites from the groundwater monitoring programme and 18 others are found in the monitoring wells.
In five agricultural watersheds, representing farmland, with wells screened from 1.5 to 5 meters depth, pesticides and metabolites have been found since 1993 in 53% of the investigated wells. The main elements are from the triazine group. Glyphosate and the metabolite AMPA, from the herbicide Roundup, is the second common group found in the agricultural watersheds, with 8 detections from 45 investigated wells.
In shallow groundwater, in the interval 0 to 20 meters depth, pesticides and metabolites have been found in more than 40% of the investigated monitoring wells and water supply wells, and the MAC level was surpassed in 15-20% of the wells. Detection of pesticides decreases with increasing depth, but pesticides and metabolites have been found at depths greater than 100 m.
In the water supply wells pesticides and metabolites have been found since 1993 in 24% of the analysed wells (1,396 wells out of 5,774 analysed). The MAC level of 0.1 mg/l was surpassed in 9% (509 of these wells). The water supply wells have been analysed for a great number of pesticides and metabolites and 46 have been found since 1993. The dichlobenil metabolite 2,6-dichlorobenzamide (BAM) is the most commonly found metabolite. BAM is found in 24% of the water supply wells and the MAC level is surpassed in 10% of the wells. In agricultural watersheds BAM is rarely found, probably due to the fact that BAM pollution is not an agricultural phenomenon, but is caused by spraying in urban areas, along roads and railways and on farmyards.
Triazines and metabolites is another group that has been found in even greater amount than BAM, but in different areas, as these compounds are found very commonly in farming areas.
All of the pesticides that have been found commonly in the groundwater are currently prohibited or strongly regulated by the Danish Environmental Protection Agency, but that does not hinder, that pesticides are imported illegally, and that they and their metabolites still and far in future will be found in groundwater.
Groundwater levels have returned to normal, and a moist early summer in 1999 resulting that the groundwater abstraction was even lower than in 1998. The total water abstraction to common waterworks in 1999 was 420 million m3 in comparison to 640 million m3 in 1989, a difference of 35%. Groundwater abstraction for irrigation was 173 million m3 in 1999, the lowest for many years.