Nitrate concentration higher than 10 mg L -1 in drinking water can cause health problems, especially in infants. Nitrates from a variety of surface and subsurface sources, such as fertilizers, are soluble in water and can leach into groundwater causing quality degradation. Groundwater from Delicias-Meoqui aquifer supplies drinking and irrigation water to six municipalities in the state of Chihuahua. A part of the area overlying this aquifer corresponds to the irrigation district DR-005, one of the most important hydro-agricultural works in Mexico. An evaluation was conducted using historical water quality data from 134 drinking water wells to make a preliminary diagnosis concerning nitrate presence in that aquifer. Water analyses showed that 34% of samples have nitrate concentrations equal or higher than the 10 mg L -1 drinking water standard. Most of these samples were from the Delicias, Saucillo and Meoqui municipalities, with approximately 180,000 inhabitants total. Undoubtedly, the high nitrate concentrations can be attributed to pollution within the irrigation district DR-005 where nitrogen fertilizers in large quantities are applied, dissolve in water and move with it through the soil profile down to groundwater. This preliminary evaluation will contribute to the development of preventative strategies that can protect groundwater in proximity to agricultural production systems from nitrate contamination.

Soil contamination by cadmium (Cd) and lead (Pb) in range and crop lands can occur from polluted sediments carried by the wind. Soils samples were obtained in three different areas on the leeward (east) side of a shallow lake called the Laguna de Bustillos: (1) sediment in the shallow lake (S), (2) soil in the range area adjacent to the shallow lake (RA), and (3) soil in agriculture land (AL) adjacent to the range area. In each area, three composite soil samples were randomly collected at depths of 0-15, 15-30 and 30-50 cm. Therefore, 45 soil samples were analyzed as a 3 (area) x 3 (depth) factorial arrangement. The samples were air dried, passed through a 2.0 mm sieve, ground and passed through a 0.355 mm sieve, and digested with concentrated nitric acid. The metals Cd and Pb were determined using ICP optical emission spectrometry. In addition pH and CE were evaluated. Cadmium concentration was statistically different among areas and showed a strong interaction between depth x area. Maximum Cd concentration was found in S with 0.94 mg kg -1 in the surface horizon (0-15 cm). Lead concentration was different among areas and the interaction was not as strong as the one noted for Cd. Highest Pb concentrations were observed in the surface horizons (0-15 cm) of both S and RA with 74.19 mg kg -1 and 55.09 mg kg -1 . Nevertheless, for the AL system the maximum Pb concentration was found in the subsurface horizon (30-50 cm) with 40.23 mg kg -1 . It is concluded that Cd and Pb are contaminating the RA and AL through wind movement with Pb contamination being the worst.