b'Environmental geophysics The future that occurred before the results of thegroundwater mapping was launched National Groundwater Mapping Projectat a national level. Furthermore, some The overall motivation for allcould be implemented in the planningof the main elements of the national participants in the national mappingand regulation of land use in areas withmapping efforts, e.g., geophysical efforts, and the proceedingspecial drinking water interests. methods and geological descriptions, extraordinary geophysicalare insensitive to the presence of developments, was to maintain andIn 51 % of all investigated waterworkspesticides and their degradation protect the wonderful, and unusual,wells in 2020, at least one pesticide wasproducts.gift that we had in Denmark: pure waterdetected, and in 14.6 % of the cases, that we could just pump up from thethe concentration exceeded the DanishAt the moment, the problem is ground and drink without any advancedquality requirement of 0.1 mg L 1. Inalleviated by mixing water from less treatment. In this overview of past andhalf of the cases, namely 25.6 % out ofpolluted and more polluted bores so present successes and failures, didthe 51 %, the presence of the substancethat the concentration goes below the we actually succeed? Seen from theDichlorophenol (DCP) was detected.recommended limit. Both large and perspective of geophysical mapping andDCP is a degradation product fromsmall waterworks stand with their backs geological/hydrogeological modelling,the herbicide Chloridazon, which wasagainst the wall having sounded the we were very successful. mainly used in beet production, andalarm to the Ministry of Environment. which has not been approved on theMost likely, at a significant number of Though many tasks remain, thereDanish market since 1996. Nevertheless,waterworks, the water will have to be is now a huge and unprecedentedDCP is the second most frequentlyfiltered, e.g., through active carbon knowledge base to assist in futurefound substance in the waterworksfilters, before the water is distributed physical planning. Nevertheless, theextraction wells. Of course, the Nationalfor consumption. The Danish state has majority of the people I have consultedGroundwater Mapping Project could notrecently announced a 130 million DKK about this Seventh Scene call for aprevent this, as the use of this pesticide(~20 million and over $AUS 31 million) better coordination between state,took place primarily before 1996, whenresearch and development project to get municipalities, and other authorities,the approval of the substance wasa better handle on the situation and to and also a better interdisciplinarywithdrawn, and thus many years beforefind possible avenues for remediation.dialogue between geophysics and (hydro)geologists to improve the hydrogeological models based on the huge amount of geophysical data and inversion models residing in our databases.However, However, while developing wonderful, advanced geophysical practices and capabilities, while improving and updating the geological knowledge of this country, and while improving hydraulic modelling capabilities generally, it became evident that mapping and administering the groundwater resources was not enough to keep the water clean. While the national mapping effort successfully provided the information that would permit a more sustainable use of the groundwater in terms of its existence and vulnerability, another issue grew to large proportions - pesticides in the groundwater! The pesticide findings in Danish drinking water wells, which presently give rise to great concern, are primarily the result of past sins. Most of the active waterworks in Denmark abstract water from considerable depths, usually more than 30 m. Leakage from the surface to 30 m or more through an undisturbed series of soil layers takes decades, so the presence of pesticides and other contaminants we see in the wells nowView over Limfjorden from Ven. A typical landscape from the north-western parts of Denmark (Palle stem predominantly from activitiesMldrup: Oil on canvas, 1980).DECEMBER 2022 PREVIEW 36'