The Influence of Sewage System on the Functioning and Quality of Krakow’s Watercourses

Table 8

Limiting contents [mg/kg] of heavy metals in suspended matter of river water for LAWA classes [10].

LAWA class	I	I-II	II	II-III	III	III-IV	IV
	Upper limit [mg/kg]
Cd	<0.3	<0.6	<1.2	<2.4	<4.8	<9.6	>9.6
Cr	<80	<90	<100	<200	<400	<800	>800
Cu	<20	<40	<80	<160	<320	<640	>640
Ni	<30	<40	<50	<100	<200	<400	>400
Pb	<25	<50	<100	<200	<400	<800	>800
Zn	<100	<200	<400	<800	<1600	<3200	>3200
Degree of solid particles pollution
	Not polluted	Not polluted to moderately polluted	Moderately polluted	Moderately polluted to strongly polluted	Strongly polluted	Strongly polluted to very strongly polluted	Very strongly polluted