Based on the characteristics of the measured water temperature by the water temperature method, which is one of the methods for infiltration and inflow, the water temperature measured using the moving average method was decomposed. And the decomposed water temperature was divided into fine weather water temperature and rainy weather water temperature. The difference in water temperature distribution between fine weather and rainy weather is expressed as a non-excess probability (power of detection), and this probability can be used as an index to evaluate the effect of infiltration of storm-water between sewage water. By using a neural network to estimate the water temperature drop due to rainfall in the measured water temperature, and then analyze the ratio of the total water temperature drop due to rainfall to the total water temperature measured during the measurement period. It was confirmed that the non-exceedance probability represents the decrease in water temperature due to rainfall. Then we conducted a flow rate survey at some water temperature measurement points. And also estimated the infiltration of storm-water ratio (= total infiltration of storm-water rate/total flow rate) using a neural network, and confirmed that there was a correlation with the non-excess probability. Therefore, by using a neural network, it was confirmed that the nonexcess probability expresses the infiltration of storm-water ratio.

　In recent years, the utilization and energy conversion of local biomass in wastewater treatment plants have been promoted. This laboratory has been conducting research and development for several years to utilize plant biomass as the dehydration assistant for sewage sludge. To date, laboratory-scale dehydration tests with a combination of plant biomass and mixed sludge or digested sludge have been performed using a centrifuge or a belt press. Sludge samples were mixed with plant biomass in ratios of 0, 10, 30, and 50 % to sludge total solids.

　The results showed that the water content of the dewatered cake was reduced by 1.5 to 14 percentage points. In addition, it was suggested that the volume of suspended solids in the effluent water after dehydration may be less than the volume when plant biomass is not used as a dehydration assistant in the case of digested sludge. When plant biomass was crushed at a wastewater treatment plant and sludge was disposed of at an incineration facility outside the sewage treatment plant, it was shown that sludge disposal costs could be reduced by 3‒7 % for digested sludge.

　Current ventilation systems with blasting ducts into sewerage pipelines close the manhole inlet. To overcome this issue, Fanless Type Ventilation System (Hole Air Streamer) which can deliver continuous blasting into manholes without using blasting ducts, have developed and introduced. Hole Air Streamer can ventilating a large volume of air into the manhole by drawing in the surrounding air (guided air effect).

　In this paper, authors reported about the Development of Hole Air Streamer (HAST-ef) applicable to different diameters, and conducted a laboratory experiments and a site of sewage pipeline experiments for confirming the performance of blowing. As the result, authors confirmed the target air flow was achieved at the targeting diameter of sewage pipeline. Furthermore, authors found that the wind delivery characteristics in the sewage pipeline could understand by comparison between the CFD (Computational Fluid Dynamics) analysis and experiments at the site of the sewage pipeline.