tailieunhanh - GROUND-WATER POLLUTION BY NITRATE

In 1981 the state of Wisconsin initiated a trading program for the point source dischargers-primarily paper mills and sewage treatment plants-along the Fox River. The state initiated the program in an effort to meet water quality standards for biological oxygen-demand pollutants. Under the program, the state (1) established a total waste load goal; (2) imposed more stringent limits on individual dischargers; and (3) under limited conditions, allowed the dischargers. | GROUND-WATER POLLUTION BY NITRATE u. Lahl B. Zeschmar B. Gabel R. Kozicki A. Podbielski B. Stachel s. Struss ABSTRACT Based on analytical data from three different institutes the pollution of ground water with nitrate ỉn the Federal Republic of Germany is quantitatively discussed. Strategies for nitrate reduction and groundwater protection are proposed. RESUME A partỉr de donnểes analytỉques de troỉs institutions differentes la pollution en nitrate de I eau souterraỉne est dỉscutée quantỉtatỉvement. Diverses solutions pour la reduction du nitrate et la protection de 1 eau sont proposes. INTRODUCTION Ground-water pollution usually occurs unnoticed and is often detected very late because sample collection is only possible by installing several observation wells. Supra-regional screening of ground-water quality in the Federal Republic of Germany is mainly based on monitoring the more than 6 000 water plants which exploit ground water and the nearly 2 million private wells for drinking water. The well depth for small water plants less than 100 000 m3 a and private wells in most cases lies between 3 and 10 meters. Therefore they are extraordinarily sensitive to pollution since the protecting soil layer is often relatively thin. Large water plants obtain their water mainly from deeper ground-water stocks down to some hundreds of meters. In areas of conventional and - above all - of intensive agricultural production increased pollution of water sinking through the soil has been observed. Hydrochemistry of sinking water can be considerably altered during subsoil passage. Some data from the drinking-water data system BIBIDAT of the Federal Bureau of Health Federal 1159 Republic of Germany point to an increase in nitrate content of ground water since the nineteen ifties especially ỉn the following regions Table 1 Region Main agricultural use Lowlands of Northern Germany potatoes turnips Lower bay of the Rhine river turnips vegetables Upper valley of the Rhine river wine .