Introduction of the Basin Sewerage Plan in Japan through Case Studies of the Lake Biwa Sewerage System

Abstract

We investigate the Japan's Master Plan of Comprehensive Sewerage System (JMPS) and Lake Biwa basin sewerage and suggest future development direction of the Watershed Sewerage System Maintenance Plan in Korea enforced on February 2, 2013. The JMPS is designed for compliance with the environmental standard for water quality under the Environmental Policy Act. The effluent standards applied in the master plan of Lake Biwa's Sewerage Plan for the Lake Biwa is tougher than the national standards. Therefore the Lake Biwa Baisn Sewerage System was the first in Japan to adopt facilities that perform advanced treatment for nitrogen and phosphorus removal. BOD, SS, T-N and T-P concentrations of discharge water of sewage are 0.9, 0.6, 5.5, 0.06 mg/L, respectively. Especially removal efficiency for BOD is 99.5 percent. It is necessary to study the diversification of the evaluation criteria, cost minimization approach, subsidy system improvement, economic concept of discharge load adjustment system and establishment of basin sewerage concept for the development of the basin sewerage plan in Korea.

HSPF-Based Assessment of Inland Nutrient Source Control Strategies to Reduce Algal Blooms in Streams in Response to Future Climate Changes

“…Therefore, it would be more practical and cost effective to control only the effluents from the six municipal WWTPs (S1 and S3 scenarios in this study) than to control all the PSs dispersed across the watershed. Among the PS reduction scenarios presented in this study, the effectiveness of limiting the effluent TP concentration of WWTPs to 0.1 mg/L for improving stream water quality has been demonstrated in Japan and the USA in separate studies [46,47]. However, controlling PSs throughout the year might be costly, and hence, seasonally varying PS control along with NPS control is suggested in this study (i.e., S3).…”

“…Although current effluent standards for WWTPs in Korea are different for different the water quality regions, the lowest numeric effluent standard for TP is 0.2 mg/L. Lake Biwa in Japan is often referred to as an excellent example of water quality improvement by enhancing the TP effluent standards for WWTPs [46,47]. Therefore, we considered the PS control scenario as a potentially effective measure for reducing algal blooms.…”

“…Thus, it is necessary to enhance nutrient control for both NPSs and PSs during the growing season. This seasonbased PS control strategy has been applied in San Diego, California, where the effluent standard for TP concentration is limited to 0.1 mg/L during the summer season [37,46,47].…”