underbore section (87 metres) of the replacement of the town’s water mains cast iron pipes last week which was in 5.6m of solid rock under the railway line. ▪ Contributed
Work on the replacement of the town’s corroded water pipes is going well however the job will take a bit longer than originally planned.
In an effort to address problems of “dirty water” Cobar Shire Council engaged reticulation replacement specialists Killard Infrastructure to upgrade 5.7km of corroded cast iron pipes in the town’s water pipeline.
Killards began work in February this year and it was estimated the project would be completed by October.
Cobar Shire Council’s water and sewer manger Victor Papierniak said an additional five lines (totaling 2.1km) have since been added to the contract post tender.
Work is now expected to be completed in December.
“We did a scope of how many cast iron pipes were in the town and it didn’t pick up on all the cast iron ones, and the old drawings didn’t show them.
“As we were digging, we found additional cast iron lines,” Mr Papierniak explained.
Some pipes along Becker Street and Linsley Street, among others, were found to be cast iron pipes rather than the asbestos cement marked on the drawings.
There was corrosion in these pipes and a decision was made to replace them as part of the current contract.
Knowing that their old drawings were incomplete and not always accurate, Mr Papierniak said they had included a contingency figure in the project’s budget to cover any unknown additional work they might encounter.
“The contingency covered most of it.
‘There was a little bit contributed from Council, but not too much at all, which is fantastic,” Mr Papierniak said.
To date 7.2km of pipeline has been replaced in Railway Parade, Bourke and Old Bourke Roads, Margaret, Prince, Fourteenth, Tenth, Brennan, Blakey, Bourke, Brough, Prince, Molineaux, Matthews and Morrison streets, Mahmong Place, Rosewood Place and Jones Drive.
“We do have a lot more work planned,” Mr Papierniak said.
He said they now aim to replace a total of 16.2km of the town’s 75km water pipeline network.
“It’s a substantial amount and over time we will slowly replace the rest of the network as part of a normal renewal plan.”
He said it was “highly likely” Council will receive also more funding to undertake an extra 5km of work which would improve water pressure in the low pressure regions of town.
During the project Killard’s staff have been using a number of innovative work practices including using laser guided boring with pipejacking and laying concrete encased pipes.
Killard’s site manager Diarmuid McGettigan said one of their biggest challenges of the project, an 87 metre underbore run to lay pipe 3.4 metres beneath the railway line and bring up to ground level and attach to the new valves (a run of 108m in total), was carried out last week.
Mr McGettigan said it took eight months of organising with the rail authority, Public Works and Council to undertake this section of work.
Since the project commenced Mr Papierniak said Council had seen a decrease in the volume of complaints from residents about their water quality.
Mr Papierniak said when the pipe replacement work is finished more high pressure scouring will be carried out.
“We will get the whole town done again and we shouldn’t see anymore water quality issues,” Mr Papierniak said.
He said with Council’s brand new water filtration plant working well and no more cast iron pipes in the system, he expects there won’t be any more water quality incidents.
“Unless there is some hidden cast iron but I think we have uncovered all that we can,”Mr Papierniak said.
He said the true test of the system will however come later at the height of summer when the town sees a higher demand for water.
