Heavy metals in suspended matter in fresh surface water in the Netherlands, 1988-2000

Substance/ standards1)		Average annual 90-percentile concentrations
		1988	1990	1995	1998	1999	2000
		mg/kg dry matter
Cadmium	Rhine	9.2	6.2	4.3	3.5	3.0	7.5
MAC: 18	Maas	649	62	41	12	12	19
DQS: 1.2	Scheldt	20.4	14.1	11.0	7.4	7.8	8.1
	IJsselmeer	2.2	3.8	2.8	1.2	1.5	1.9
	nationally managed waters	138.5	18.3	12.9	5.7	5.6	8.4
Chromium	Rhine	134	156	118	114	99	115
MAC: 570	Maas	183	257	147	111	129	132
DQS: 150	Scheldt	194	205	202	135	135	138
	IJsselmeer	63	150	96	53	60	62
	nationally managed waters	148	184	138	102	104	110
Copper	Rhine	151	150	113	125	97	93
MAC: 110	Maas	303	315	180	192	233	177
DQS: 54	Scheldt	164	173	139	105	109	90
	IJsselmeer	34	75	62	33	38	32
	nationally managed waters	154	170	118	110	112	95
Mercury	Rhine	1.7	2.1	1.3	1.3	1.0	1.1
MAC: 15	Maas	2.8	3.2	2.4	1.1	1.1	1.1
DQS: 0.45	Scheldt	1.5	1.4	1.7	1.3	1.2	1.0
(inorganic	IJsselmeer	0.6	0.9	1.1	0.5	0.4	0.4
mercury)	nationally managed waters	1.7	1.8	1.6	1.1	1.0	1.0
Nickel	Rhine	61	81	62	56	51	60
MAC: 66	Maas	69	103	88	68	73	85
DQS: 53	Scheldt	55	71	63	37	38	40
	IJsselmeer	32	96	60	29	33	31
	nationally managed waters	57	87	76	48	50	56
Lead	Rhine	203	179	146	163	135	179
MAC: 800	Maas	650	328	303	259	314	315
DQS: 128	Scheldt	218	199	193	152	159	142
	IJsselmeer	76	120	100	63	71	54
	nationally managed waters	281	210	183	157	164	167
Zinc	Rhine	821	843	702	692	543	833
MAC: 930	Maas	4 825	4 015	2 057	1 479	1 626	1 478
DQS: 210	Scheldt	843	809	916	553	633	546
	IJsselmeer	420	741	613	330	385	328
	nationally managed waters	1 600	1 463	1 032	744	768	759
Source: Commissie Integraal Waterbeheer						RIVM/EDC/Oct02
1) Maximum allowable concentration (MAC) and desired quality standard (DQS).

Rectification

The figures in the printed version of the 2001 Environmental Data Compendium are not correct. The incorrect figures were also on this site for a while. The figures above are the right ones.

Development

Heavy metals combine to a greater or lesser extent with suspended matter. The concentrations of heavy metals in suspended matter in fresh surface water are decreasing over time, even if the pattern is sometimes rather unpredictable. Chromium, mercury and lead do not exceed the MAC anywhere. Cadmium, copper, nickel and zinc exceed the MAC in the River Maas . The relatively low metal levels in suspended matter are a feature of the IJsselmeer. In regionally managed waters, there is no systematic measuring of heavy metals in suspended matter.

Policy

The aim of the policy is to reduce the levels of metals to below the MAC and, in the slightly longer term, to below the DQS.

Relevance

The quality of the suspended matter determines the quality of the river, lake or sea bed. The values for the MAC are based on ecotoxicological grounds. That means that, when the MAC is exceeded, negative effects on organisms cannot be excluded.

Monitoring sites

• The monitoring sites in the rivers are sites chosen by the Commissie Integraal Waterbeheer/Commissie Uitvoering Wet Verontreiniging Oppervlaktewater (CIW/CUWVO).
• For bodies of water under national management a group of monitoring sites was compiled from 25 representative sites selected by this committee from the entire monitoring network of national water bodies. It includes sites in the Rhine, Maas, Scheldt, IJssel, IJsselmeer and in a number of canals and lakes.

Technical note

These sites are situated in large regionally-managed water bodies. The new CIW data are requested each year from the district water boards and the charts are then updated.
A 90 percentile is the concentration level that is exceeded in 10% of the measurements. If an average is entered for several locations, this is an average of the annual averages for the 90 percentiles supplied for each site.

References

• CIW (2002). Water in Beeld 2002; Voortgangsrapportage over het Waterbeheer in Nederland. Commissie Integraal Waterbeheer, The Hague.

Relevant sections and indicators in the Environmental Data Compendium

• Surface water quality: Policy
• Heavy metals in fresh surface water in the Netherlands
• Eutrophying substances in fresh surface water in the Netherlands, 1985-2001
• Heavy metals in suspended matter in brackish surface water (page is not available yet)
• Emissions into water in the Netherlands, 1990-2001
• Discharges into water and burden on surface water in the Netherlands, 1990, 1995, 1999 and 2000
• PCB and mercury in eels in the Netherlands, 1980-2000

Relevant information outside of the Environmental Data Compendium

• More information about the monitoring of nationally managed waters.