Table 3.

Legal requirements concerning treated wastewater discharges in non-EU countries/regions

Country/region	WWTP category	COD, mg/l	BOD5, mg/l	NH4+–N, NH3–N, mg/l	NO2−–N, NO3−–N, mg/l	TN, mg/l	PO43−–P, mg/l	TP, mg/l	References
Belarus	<500 PE	125	35	n/na	n/n	n/n	n/n	n/n	Ministry of Environment (2012)
	501–2000 PE	120	30	20	n/n	n/n	n/n	n/n
	2001–10,000 PE	100	25	15	n/n	n/n	n/n	n/n
	10,001–100,000 PE	80	20	n/n	n/n	20	n/n	4.5
	>100,000 PE	70	15	n/n	n/n	15	n/n	2
Switzerland	200–10,000 PE	60	20	2 (sum of NH3–N and NH4–N)	0.3 (NO2−–N)	n/n	0.8	n/n	The Swiss Federal Council (1998)
	>10,000 PE	45	15	2 (sum of NH3–N and NH4–N)	0.3 (NO2−–N)	n/n	0.8	n/n
China (Taihu Lake catchment)	n/n	50	n/n	8 (NH4+–N, 5 in winter season)	n/n	15	n/n	0.5	Li et al. (2012)
USA	n/n	n/n	30	n/n	n/n	3–5 (areas sensitive to eutrophication)	n/n	1.0–0.1 (areas sensitive to eutrophication)	Sedlak (1991), US EPA (2012)
BC, Canada	Streams, rivers and estuaries	n/n	45 (10 if dilution ratio < 40:1)	n/n	n/n	n/n	0.5 (MDFb > 50 m3/d)	1.0 (MDF > 50 m3/d)	British Columbia Office of Legislative Counsel Ministry of Attorney General (2005), US EPA (2012)
	Lakes	n/n	45	n/n	n/n	n/n	0.5 (MDF > 50 m3/d)	1.0 (MDF > 50 m3/d)
	Open marine water	n/n	130 (MDF > 10 m3/d)	n/n	n/n	n/n	n/n	n/n
	Coastal waters	n/n	45 (MDF > 10 m3/d)	n/n	n/n	n/n	n/n	n/n
Dubai	Harbor area	100	50	2 (NH4+–N)	40 (NO3−–N)	10 (TKNc)	2	n/n	Government of Dubai (2010, 2018)
	Open Sea	n/n	30	5 (NH3–N)	n/n	n/n	0.1	n/n

^an/n not normalized parameter

^bMDF maximum daily flow

^cTKN as a sum of organic nitrogen (N_org) and NH₄⁺–N