Nation-wide Effluent Water Quality Standards for Conservation of the Living Environment (Japan)

Living Environment Items	Permissible Limit
hydrogen ion activity (pH)	Non-Coastal Regions 5.8-8.6 Coastal Regions 5.0-9.0
biochemical oxygen demand (BOD)	160mg/L (Daily Average 120mg/L)
chemical oxygen demand (COD)	160mg/L (Daily Average 120mg/L)
suspended solids (SS)	200mg/L (Daily Average 120mg/L)
n-hexane extracts (mineral oil)	5mg/L
n-hexane extracts (animal and vegetable fats)	30mg/L
phenols	5mg/L
copper	3mg/L
zinc	5mg/L
dissolved iron	10mg/L
dissolved manganese	10mg/L
chromium	2mg/L
number of coliform groups	Daily Average 3000/cm³
nitrogen	120mg/L (Daily Average 60mg/L)
phosphorus	16mg/L (Daily Average 8mg/L)

Remarks
1	The effluent standards listed in this table apply to the effluents of factories or commercial facilities which discharge 50 m³ or more of effluent per day on average.
2	The effluent standards for biochemical oxygen demand (BOD) apply exclusively to the effluents discharged in public waters other than the seas and lakes; the effluent standards for chemical oxygen demand (COD) apply exclusively to the effluents discharged in sea and lake areas.
3	The effluent standards for nitrogen content only apply to lakes and reservoirs designated by the Minister of the Environment as being susceptible to lake plankton blooms due to nitrogen, sea areas designated by Minister of the Environment as being susceptible marine phytoplankton blooms due to nitrogen, and effluents discharged into public water areas.
4	The effluent standards for phosphorus content only apply to lakes and reservoirs designated by the Minister of the Environment as being susceptible to lake plankton blooms due to phosphorus, sea areas designated by Minister of the Environment as being susceptible marine phytoplankton blooms due to phosphorus, and effluents discharged into public water areas.