Water Pollution Control Law : Roles of Local Government in Water Quality Control (Japan)
WEPA Water Environment Partnership in Asia

Roles of Local Government in Water Quality Control


Prefectural governments are playing very important roles in environmental water quality management. Their responsibilities include establishing more stringent standards. Cinspection of specified factories, and regulating effluents discharged from factories. They are also responsible for establishing and implementing environmental water quality monitoring programs within their juridifications. Aside from prefectural governments. city governments in71cities specified in the Water Pollution Control Law as “designated cities” are empowered to inspect and regulate effluent discharges of factories in their respective areas of juridification.

Water quality monitoring parameters are given in the following Table. Water quality monitoring is conducted in rivers four times a day throughout the year. Four times a day, i.e., every six hours, river water samples are taken to determine the daily and seasonal fluctuation of flow rates and water quality. Seasonal changes in water quality are monitored in lakes since obvious daily changes in lake water quality are seldom observed.

Pollution control measures undertaken by prefectural governments include:

  1. Regulating factories based on laws and ordinances;
  2. Maintaining and constructing additional sewerage lines and sewage treatment systems;
  3. Aerating Sagami Lake;
  4. Purifying water in waterways;
  5. Controlling pollution from new high-tech industries such as the electronic industries.
Table Water quality monitoring parameters
Categories Parameters
Toxic substances Cd, CN, Pb, Cr (VI), As, Hg (total), Hg (alkyl), PCBs, Trichloroethylene, Tetrachloroethylene, Dichloromethane, Carbon tetrachloride, 1,2-Dichloroethan, 1,1-Dichloroethylene, Cis-1,2-Dichloroethylene, 1,1,1-Trichloroethane, 1,1,2-Trichloroethane, 1,3-Dichloropropene, Thiuram, Simazine, Thiobencarb, Benzene, Selenium and compounds
Parameters for living environment pH, BOD, CODMn, SS, DO, Number of coliforms, n-Hexane extracts, Total nitrogen, Total phosphorus
Special parameters involved in living environment parameters Phenols, Copper, Zinc, Dissolved ion, Dissolved manganese, Chromium, Fluorine, Nickel, ENP
Other parameters Ammoniacal nitrogen, Nitrite, Nitrate, Phosphorus, Chloric ion, Salts, 1,1,1-Trichloroethane, Anionic surfactant, Chlorophyll-a
Physical parameters Weather, Weather of previous day, Water depth, Sampling depth, Water flow rate, Flow, Atmospheric temperature
Specific Regulations and Systems

Water Pollution Control Law

Reference: Okada M, Peterson SA.(2000): “Water Pollution Control Policy and Management: the Japanese Experience”. Gyosei, Japan, 287pp.
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