Nepean Storage - Fourth Quarter 2003/2004

NEPEAN (Raw Water) 1 April 2004 to 30 June 2004
		MICROBIOLOGICAL			PHYSICAL / CHEMICAL
		*E. coli*	*Giardia*	*Crypto*	turbidity	dissolved oxygen	True colour	Phosphorus	Nitrogen	Chlorophyll a	Iron	aluminium	Manganese
		Orgs /100mL	cysts /100L	oocysts /100L	(NTU)	(mg/L)	HU	(µg/L)	(µg/L)	(µg/L)	(µg/L)	(µg/L)	(µg/L)
	Reference levels*	**	**	**	**	>6	**	5-50	100-500	2-10	<1000	<100	**
Lake Nepean DNE 2	No. of results	12	0	0	12	199	12	12	12	4	12	12	12
	Minimum	0	.	.	1.1	6.5	5	5	300	2.6	52	10	31
	Average	-	-	-	1.7	8.4	6	6	351	3.4	130	10	96
	Maximum	4	.	.	2.8	10.0	7	8	410	4.9	181	14	168

Manganese is naturally occurring in the lake sediments and can become soluble, causing increased levels in the water.

* Australian Water Quality Guidelines for Fresh and Marine Waters, ANZECC, 1992.

** no guideline set for Raw Water

ANNUAL

NEPEAN DAM (Raw Water) 1 July 2003 to 30 June 2004
		MICROBIOLOGICAL			PHYSICAL / CHEMICAL
		*E. coli*	*Giardia*	*Crypto*	turbidity	dissolved oxygen	True colour	Phosphorus	Nitrogen	Chlorophyll a	Iron	aluminium	Manganese
		Orgs /100mL	cysts /100L	oocysts /100L	(NTU)	(mg/L)	HU	(µg/L)	(µg/L)	(µg/L)	(µg/L)	(µg/L)	(µg/L)
	Reference levels*	**	**	**	**	>6	**	5-50	100-500	2-10	<1000	<100	**
Lake Nepean DNE 2	No. of results	42	0	0	41	776	42	42	42	14	42	42	42
	Minimum	0	.	.	0.7	4.9	5	4	260	2.6	43	10	5
	Average	-	-	-	1.4	8.3	7	7	359	4.3	103	16	56
	Maximum	4	.	.	2.8	11.8	10	13	450	6.6	181	46	170

* Australian Water Quality Guidelines for Fresh and Marine Waters, ANZECC, 1992.

** no guideline set for Raw Water