Modern analytical techniques have been applied to investigate the nature of lead pipe corrosion products formed in pH adjusted, orthophosphate-treated, low alkalinity water, under supply conditions. Depth profiling and surface analysis have been carried out on pipe samples obtained from the water distribution system in Glasgow, Scotland, UK. X-ray diffraction spectrometry identified basic lead carbonate, lead oxide and lead phosphate as the principal components. Scanning electron microscopy/energy-dispersive x-ray spectrometry revealed the crystalline structure within the corrosion product and also showed spatial correlations existed between calcium, iron, lead, oxygen and phosphorus. Elemental profiling, conducted by means of secondary ion mass spectrometry (SIMS) and secondary neutrals mass spectrometry (SNMS) indicated that the corrosion product was not uniform with depth. However, no clear stratification was apparent. Indeed, counts obtained for carbonate, phosphate and oxide were well correlated within the depth range probed by SIMS. SNMS showed relationships existed between carbon, calcium, iron, and phosphorus within the bulk of the scale, as well as at the surface. SIMS imaging confirmed the relationship between calcium and lead and suggested there might also be an association between chloride and phosphorus.

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The United States-Mexico border area faces the challenge of integrating aspects of its binational physical boundaries to form a unified or, at least, compatible natural resource management plan. Specified geospatial components such as stream drainages, mineral occurrences, vegetation, wildlife, and land-use can be analyzed in terms of their overlapping impacts upon one another. Watersheds have been utilized as a basic unit in resource analysis because they contain components that are interrelated and can be viewed as a single interactive ecological system. In developing and analyzing critical regional natural resource databases, the Environmental Protection Agency (EPA) and other federal and non-governmental agencies have adopted a "watershed by watershed" approach to dealing with such complicated issues as ecosystem health, natural resource use, urban growth, and pollutant transport within hydrologic systems. These watersheds can facilitate the delineation of both large scale and locally important hydrologic systems and urban management parameters necessary for sustainable, diversified land-use. The twin border cities area of Nogales, Sonora and Nogales, Arizona, provide the ideal setting to demonstrate the utility and application of a complete, cross-border, geographic information systems (GIS) based, watershed analysis in the characterization of a wide range of natural resource as well as urban features and their interactions. In addition to the delineation of a unified, cross-border watershed, the database contains sewer/water line locations and status, well locations, geology, hydrology, topography, soils, geomorphology, and vegetation data, as well as remotely sensed imagery. This report is preliminary and part of an ongoing project to develop a GIS database that will be widely accessible to the general public, researchers, and the local land management community with a broad range of application and utility.

The Dumfries Basin aquifer supports groundwater abstraction for public supply, agriculture and industry. Abstraction is concentrated in the western part of the basin, where falling groundwater levels and deteriorating water quality both reflect the effects of intense pumping. There are two bedrock units: a predominantly breccia-coarse sandstone sequence in the west, interfingering with a predominantly sandstone sequence in the NE and east. The basin is bounded by weakly permeable Lower Palaeozoic rocks, and is largely concealed by variable superficial deposits. Surface water flows onto the basin from the surrounding catchment via the Nith and the Lochar Water and their respective tributaries. Direct rainfall recharge occurs via superficial sands and gravels, especially in the north, and discharge is predominantly to the rivers in the central area rather than the sea. A picture is developing of two main aquifer types within the basin: the high-transmissivity western sector underlain by a fracture-flow system with younger water and active recharge and a high nitrate content, compared with the east where groundwater residence times are longer and the storage capacity is higher.