Sparsely located small water supply facilities are regularly inspected by maintenance patrols. Effective patrol strategy for facilities with different inspection periods, namely, every day, every two days and every 4 days, were investigated. An optimization model was formulated in which the patrol days for all facilities and optimal patrol root for each day should be determined with the objective of minimizing total patrol time. Use of automatic analyzers was also examined in order to reduce inspection cost. Case study was carried out and the developed method was verified.

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An integrated risk assessment model for the solid waste landfill was developed. The behaviors of the contaminants from different sources (leakage of leachate through the bottom liner, discharge of the treated leachate to the river, landfill gas) via various media (aquifer, river, air, vegetables, fruits, fish etc.) were described by the equations as simple as possible based on the previous studies. By using this model, the risk of the virtual municipal solid waste landfill was calculated. Benzene, arsenic and dioxin were selected as the representative contaminants. Calculation results showed that the risk of the landfill was extremely smaller than the risk before the landfill is constructed (background risk). The risk derived from the discharge of the treated leachate to the river comprised a large percentage of the risk of the landfill, except the proportion of the risk derived from the landfill gas was large for benzene in the beginning of the landfill operation. Therefore, the difference of bottom liner types (single geomembrane liner and composite liner) had little influence on the risk. Moreover, the sensitivity analysis was conducted for the parameters for landfill property, meteorological condition, aquifer & river properties and life-style of residents. The result showed that the parameters for landfill property (the concentration of contaminants in leachate, the area of the landfill) had a large impact on the increase of the risk.

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Soil vapor extraction, Air sparging and Bioveting methods are commonly used for the remediation of the soil and ground water polluted by toxic volatile organic chemicals. The coefficient of air permeability and the influence radius of vacuum pumping are the important indices for the application of these methods. In order to meet to these demands, the in-situ vacuum tests are often conducted. However, very little attention has been paid for analyzing the data taken from the in-situ vacuum tests due to the lack in the reliable and quantitative studies. In the present paper, the numerical solutions by the finite element method and the analytical solutions for air extraction from the vacuum well and borehole were examined. It was concluded that the present method for determining the coefficient of air permeability and the influence radius of vacuum pumping is applicable for the in-situ vacuum tests.

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The highly concentrated fluoride in groundwater has been observed in confined aquifers of the alluvial sediments in the Chiang Mai Basin. Nanofiltration process has been applied to the control of fluoride exposure to the local residents, which caused the serious dental and osteal fluorosis.
A polyamide nanofiltration is widely used for the membrane plants, which was found to be limited fluoride removal by a function of feeding pH. In contrast to neutrality to weak basic condition that gave high fluoride removal, it tended to form calcium carbonate scale on the membrane surface. This study showed optimum combination of pretreatment and permeate recovery in the membrane operation.

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Variable rate program with two-tier pricing is in the minority in Japan. But, this method has an advantage that to show a goal to reduce waste. This goal setting make people have garbage awareness and sense of recycling. The specific goal setting serves as a source of encouragement for people who want to give consideration to global and local environment, and that make people choice several environmental conscious actions. The other way, if the amout of rubbish that are collected free of charge is much then people do not have garbage awareness and sense of recycling. And, because there is not an economic merit for such people, these people do not waste reduction action. Therefore, decisions of the number stickers for waste bag that are given out free of charge and the collection charge of a case beyond quantity of setting garbage collection in variable rate program with two-tier pricing.

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The amount of sewage sludge produced in municipal wastewater treatment plants in Japan is increasing every year correlating with the increasing of urban population. Therefore, the solubilization process, one method to reduce and recover the resource from the sludge, was considered as a promising solution. Especially, subcritical water process was applied to dissolve various of matters in the sludge. Moreover, it was possible to recover the resources from the dissolved sludge with some kinds of treatment. In the study, alkali was applied to be added in subcritical water process for the sludge solubilization in different temperatures. As the results, solubility of sludge was improved by 15%. Besides, the optimum addition amount of alkali that affected the resources (sugar, protein, phosphate and ammonia nitrogen) leaching from the sludge was evaluated.

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This paper explains the development and full-size model test result of a noise reduction device for Shinkansen. The device is developed by altering the upper shape of existing soundproofing wall, aiming effective noise decrease for Shinkansen running at the higher speed. The relation between soundproofing wall shape and noise reduction was estimated by numerical analyses and full-scale model experiment, and from the experiment results, more effective wall shape was designed.
Full-size model test showed that the developed device did not show any advantage for pantograph originated noise compared to equal-height extensive board, but it was effective for the noise from rail, reducing about 4.5dB.

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A proliferation of bamboo which has not been managed is recognized as an environmental and ecological problem. When considering regeneration and maintenance of a forest, it is important to clarify geo-environmental characteristic of the spreading bamboo groves. This paper reports a combination of contiguous bamboo groves and an intrusion of bamboo into other vegetation, based on distribution map of bamboo groves in Yamaguchi prefecture. According to analysis of aerial photograph and field survey, a front of bamboo grove is spreading in the range of 0.7 to 2.5 m/year.

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