The Tula Valley receives untreated wastewater from Mexico City for agricultural irrigation, half of which infiltrates to aquifers from where drinking water is extracted. Samples of wastewater and infiltrated water from three areas of the valley were analyzed for microorganisms, organic micropollutants, and some basic parameters. Concentrations of microorganisms in the infiltrated water were generally very low but the incidence of fecal coliforms (present in 68% of samples), somatic bacteriophages (36%), Giardia spp. (14%), and helminth eggs (8%) suggested a health risk. Organic micropollutants, often present at high concentrations in the wastewater, were generally absent from the infiltrated water except carbamazepine which was in 55% of samples (up to 193 ng/L). There was no correlation between carbamazepine concentrations and the presence of microorganisms but highest concentrations of carbamazepine and boron coincided. A treatment such as nanofiltration would be necessary for the infiltrated water to be a safe potable supply.

Using the monthly hydrogeochemical data of ChangLe River system from 2004 to 2008, total nitrogen (TN) export load (Sₙ) from nonpoint sources (NPS) to stream and in-stream attenuation load (AL) was estimated by the inverse and forward format of an existing in-stream nutrient transport equation, respectively. Estimated Sₙ contributed 96±2% of TN entering the river system, while AL reduced the input TN by 23±14% in average. In-stream TN attenuation efficiency in high flow periods (10±5% in average for the entire river system) was much lower than that in low flow periods (39±17%). TN attenuation efficiency in tributaries (28±16% in average) was much higher than that in mainstream (11±8%). Hydrological conditions are important in determining the spatio-temporal distributions of NPS TN export, stream attenuation and discharge. Increasing the water residence time might be a practical method for mitigating stream TN.

Simulation procedure integrated with multi-scale in horizontally regional–urban-point levels and in vertically atmosphere–surface–unsaturated–saturated layers, was newly developed in order to predict the effect of urban geometry and anthropogenic exhaustion on the hydrothermal changes in the atmospheric/land and the interfacial areas of the Japanese megalopolis. The simulated results suggested that the latent heat flux in new water-holding pavement (consisting of porous asphalt and water-holding filler made of steel by-products based on silica compound) has a strong impact on hydrologic cycle and cooling temperature in comparison with the observed heat budget. We evaluated the relationship between the effect of groundwater use as a heat sink to tackle the heat island and the effect of infiltration on the water cycle in the urban area. The result indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle there.

As part of a regional screening to evaluate the risk, for the health of populations, to certain classes of emerging substances, several families of pharmaceuticals and hormones were looked for in waters intended to drinking. Thus, 52 substances were investigated in 71 surface waters and 70 groundwaters. Results indicate that no water was free of pollutants, regardless of its origin (surface or groundwater) and the season of collect. The pharmaceuticals most frequently detected and with the highest concentration levels were salicylic acid, carbamazepine and acetaminophen. Among hormones, testosterone, androstenedione and progesterone were detected in almost all the samples. Globally the groundwaters were less contaminated than surface waters in regards pharmaceuticals frequencies and levels. On the other side, androgens and progestagens were present with comparable frequencies and levels in both compartments. The risk linked to the presence of these substances on human health is discussed.

Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs.

Quantifying diffuse sources of pollution is becoming increasingly important when characterising river catchments in entirety – a prerequisite for environmental management. This study examines both low and high flow events, as well as spatial variability, in order to assess point and diffuse components of zinc pollution within the River West Allen catchment, which lies within the northern England lead–zinc Orefield. Zinc levels in the river are elevated under all flow regimes, and are of environmental concern. Diffuse components are of little importance at low flow, with point source mine water discharges dominating instream zinc concentration and load. During higher river flows 90% of the instream zinc load is attributed to diffuse sources, where inputs from resuspension of metal-rich sediments, and groundwater influx are likely to be more dominant. Remediating point mine water discharges should significantly improve water quality at lower flows, but contribution from diffuse sources will continue to elevate zinc flux at higher flows.

The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse.

Little is known about the importance of drainage/irrigation channels and biogeochemical processes in arsenic distribution of shallow groundwaters from the Hetao basin. This investigation shows that although As concentrations are primarily dependent on reducing conditions, evaporation increases As concentration in the centre of palaeo-lake sedimentation. Near drainage channels, groundwater As concentrations are the lowest in suboxic-weakly reducing conditions. Results demonstrate that both drainage and irrigation channels produce oxygen-rich water that recharges shallow groundwaters and therefore immobilize As. Groundwater As concentration increases with a progressive decrease in redox potential along the flow path in an alluvial fan. A negative correlation between SO₄ ²⁻ concentrations and δ³⁴S values indicates that bacterial reduction of SO₄ ²⁻ occurs in reducing aquifers. Due to high concentrations of Fe (>0.5mgL⁻¹), reductive dissolution of Fe oxides is believed to cause As release from aquifer sediments. Target aquifers for safe drinking water resources are available in alluvial fans and near irrigation channels.

A superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments.

A detailed study of the free and conjugated estrogen load discharged by the eight major sewage treatment plants into the Yodo River basin, Japan was carried out. Sampling campaigns were focused on the winter and autumn seasons from 2005 to 2008 and the free estrogens estrone(E1), 17β-estradiol(E2), estriol(E3), 17α-ethynylestradiol(EE2) as well as their conjugated (sulfate and glucuronide) forms. For both sewage effluent and river water E2 and E1 concentrations were greatest during the winter period (December–March). This coincides with the period of lowest rainfall and lowest temperatures in Japan. E1 was the dominant estrogenic component in effluent (means of 10–50 ng/L) followed by E2 (means of 0.5–3 ng/L). The estrogen sulfate conjugates were found intermittently in the 0.5–1.7 ng/L concentration range in the sewage effluents. The greatest estrogen exposure was found to be in the Katsura River tributary which exceeded 1 ng/L E2-equivalents during the winter period.