Hon Jim Scott questions increasing metal levels in Cockburn Sound sediments, linking it to industrial discharge licenses. The Minister's response highlights data comparison issues and multiple potential pollution sources, including natural ones.

AnsweredQoN 169Legislative Council
Asked
8 August 2001
Portfolio
the Environment and Heritage

QuestionView source ↗

The table on page 31 of the State of Cockburn Sound report indicates that for the metals chromium, mercury, copper and zinc the levels present in sediments is increasing in parts of Cockburn Sound -
(1) Is the cause of this increasing accumulation of metals due to the high licence and discharge rates of those metals permitted into the Sound?
(2) If no, what is the cause of the accumulating metals?

AnswerView source ↗

Answered
18 September 2001
Responded by
Minister for Housing and Works representing the Minister for the Environment and Heritage
Response time
41 days
I refer the Hon Jim Scott to Page 30 of the State of Cockburn Sound report which explains that care needs to be taken in comparing the 1994 and 1999 sediment results. This is due to the highly variable nature of sediments, differences in sampling locations and difficulties in accurately analysing for metals when the levels are near laboratory detection levels. 2. It is not possible to solely contribute the levels of these metals in Cockburn Sound to industrial discharges. Their presence may be attributed to a number of potential sources, including: industrial discharges, stormwater runoff, groundwater inputs from the catchment, boats and ships, and natural deposits. I bring to the Hon member's attention to the Table on page 31 where it shows a similar trend between the two sampling dates for sites in Warnbro Sound, which doesn't receive any industrial discharges.
2. It is not possible to solely contribute the levels of these metals in Cockburn Sound to industrial discharges. Their presence may be attributed to a number of potential sources, including: industrial discharges, stormwater runoff, groundwater inputs from the catchment, boats and ships, and natural deposits. I bring to the Hon member's attention to the Table on page 31 where it shows a similar trend between the two sampling dates for sites in Warnbro Sound, which doesn't receive any industrial discharges.
I bring to the Hon member's attention to the Table on page 31 where it shows a similar trend between the two sampling dates for sites in Warnbro Sound, which doesn't receive any industrial discharges.

Explore WA Government Data

Search the full archive in the free dashboard, or query programmatically via API.

Explore more