Mr STIRLING - 1998-10-08
The sewerage system breakdown in Cullen Bay, which has recently led to human excrement pouring through streets and homes, is an absolute disgrace. Residents have told us that the sewerage system has never been up to the job. Residents have also told us that the Power and Water Authority only approved the sewerage system after being pressured by a Country Liberal Party minister. Can the minister explain to the House how this sewerage system was approved?
ANSWER
Madam Speaker, I thank the honourable member for his question. The facts are, of course, that the Cullen Bay No. 4 pump station, in Paspaley Place, failed on the night of Wednesday 23 September and again on Saturday night, 26 September 1998. A small number of customers experienced a discharge of effluent into their premises and for a period of several hours raw sewage overflowed into the marina. But I should say the Cullen Bay sewerage system continued to operate throughout both mechanical failures relating to this pump station. The system is designed for sewerage overflow to go into the marina in the event of a pump failure.
As a consequence of those outages, local residents called a public meeting and that took place on Monday 28 September. The Power and Water Authority investigated the mechanical failures at the station and that investigation was completed on 28 September. The repair of the pumps etc and power was restored with both pumps becoming operational by 10.30pm on 29 September.
The Power and Water Authority has engaged an expert engineering consultant to conduct an investigation of the Cullen Bay sewerage system. The consultant’s investigation is obviously in response to concern by local residents that the failure of the system is due to design faults and the inability of the system to handle the current and future loads.
Mr Stirling: How was it ever approved?
Mr POOLE: Well, if the honourable member would listen, I will tell him. Assuming that the claims are determined to be correct, the Authority will provide recommendations on any remedial action that is required. This will occur obviously as soon as information is received.
I am told that the Authority had reservations about the system’s ability to cope with the demand and the ability to cope with the impact of settlement of earth works in Cullen Bay. Some settlement has occurred and the material and the equipment used by the developers will also be re-checked. Apparently the initial investigation indicates that there was a lack of flexible couplings to tanks. Basically, what has happened is that, as in all new building areas, particularly an area where you have dredged and filled, backfilled and reclaimed, the main sewerage tanks have settled slightly. The sewerage system has settled slightly and the couplings between the two, which apparently are not flexible couplings, have simply sheared off. Now that indicates to me a design fault and I await the report with interest.
Members interjecting.
Mr POOLE: I understand that the Power and Water Authority is doing exactly this. They are investigating what ...
Mr Bailey: interjecting.
Madam SPEAKER: Order!
Mr POOLE: There is no indication of any ministerial interference ...
Members interjecting.
Madam SPEAKER: Order!
Mr POOLE: We are investigating the legal obligation of the developers with regards to this problem and I understand that in any event this system is quite a complicated system. It always is when you are, as they say, pushing sewerage up hill, which in effect is what they are doing down at Cullen Bay. I have been assured by the Power and Water Authority that the problem will be completely solved as we continue with the sewerage redevelopment that is already planned for that area as part of the major redevelopment of Darwin’s sewerage system.
I understand that the initial repairs have been made. We will probably increase the size of one of the tanks down there and see what we can bill back to the developer, continue on with the redevelopment of the Darwin sewerage and bring it forward by a few months to fix the problem forever.
ANSWER
Madam Speaker, I thank the honourable member for his question. The facts are, of course, that the Cullen Bay No. 4 pump station, in Paspaley Place, failed on the night of Wednesday 23 September and again on Saturday night, 26 September 1998. A small number of customers experienced a discharge of effluent into their premises and for a period of several hours raw sewage overflowed into the marina. But I should say the Cullen Bay sewerage system continued to operate throughout both mechanical failures relating to this pump station. The system is designed for sewerage overflow to go into the marina in the event of a pump failure.
As a consequence of those outages, local residents called a public meeting and that took place on Monday 28 September. The Power and Water Authority investigated the mechanical failures at the station and that investigation was completed on 28 September. The repair of the pumps etc and power was restored with both pumps becoming operational by 10.30pm on 29 September.
The Power and Water Authority has engaged an expert engineering consultant to conduct an investigation of the Cullen Bay sewerage system. The consultant’s investigation is obviously in response to concern by local residents that the failure of the system is due to design faults and the inability of the system to handle the current and future loads.
Mr Stirling: How was it ever approved?
Mr POOLE: Well, if the honourable member would listen, I will tell him. Assuming that the claims are determined to be correct, the Authority will provide recommendations on any remedial action that is required. This will occur obviously as soon as information is received.
I am told that the Authority had reservations about the system’s ability to cope with the demand and the ability to cope with the impact of settlement of earth works in Cullen Bay. Some settlement has occurred and the material and the equipment used by the developers will also be re-checked. Apparently the initial investigation indicates that there was a lack of flexible couplings to tanks. Basically, what has happened is that, as in all new building areas, particularly an area where you have dredged and filled, backfilled and reclaimed, the main sewerage tanks have settled slightly. The sewerage system has settled slightly and the couplings between the two, which apparently are not flexible couplings, have simply sheared off. Now that indicates to me a design fault and I await the report with interest.
Members interjecting.
Mr POOLE: I understand that the Power and Water Authority is doing exactly this. They are investigating what ...
Mr Bailey: interjecting.
Madam SPEAKER: Order!
Mr POOLE: There is no indication of any ministerial interference ...
Members interjecting.
Madam SPEAKER: Order!
Mr POOLE: We are investigating the legal obligation of the developers with regards to this problem and I understand that in any event this system is quite a complicated system. It always is when you are, as they say, pushing sewerage up hill, which in effect is what they are doing down at Cullen Bay. I have been assured by the Power and Water Authority that the problem will be completely solved as we continue with the sewerage redevelopment that is already planned for that area as part of the major redevelopment of Darwin’s sewerage system.
I understand that the initial repairs have been made. We will probably increase the size of one of the tanks down there and see what we can bill back to the developer, continue on with the redevelopment of the Darwin sewerage and bring it forward by a few months to fix the problem forever.
Last updated: 09 Aug 2016