Mains scouring goes to tender

Gosford Council officers have recommended that council accept a tender from company Mainsclean to clean water mains by air scouring.

Council recently trialed the cleaning of water mains by air scouring in two pilot areas, including the Peninsula.

Council had been experiencing a high incidence of discoloured water on the Woy Woy Peninsula and other areas.

The water used in the cleaning process was transferred to tankers and transported to Council's Water Treatment Plant at Somersby for re-processing.

A council staff report stated that valuable information was gained by the trials and was used to develop contract documents.

The contract services include the cleaning of mains and transportation of discoloured water to Somersby.

Tenders were received from the four companies Mainsclean, Transpacific Industrial Solutions, CTS-Tyco and Utility Services.

Mainsclean was the company that completed the two pilot areas and had experience in the transporting discoloured water.

The company had allowed for a tanker capacity of 75,700 litres increasing to 99,700 litres (and sometimes 123,700 litres) for larger size mains and was expecting to complete the work in 43 shifts.

The staff report stated that the pilot areas were completed in a "very satisfactory manner".

It stated that 5.99 megalitres of discoloured would need to be transported and that a minimum of three tankers with a total capacity of 60,000 litres would be required to complete the cleaning works in 32 to 36 shifts.

The contract provides for the payment of tankers on a per shift basis.

If the number of shifts increases, the costs to council increase.

"Past performance of the recommended tenderer would indicate the company has the capability and experience to carry out the work in accordance with council's specification," it stated.

Council agenda WAT.18, July 25