Vaughn Ellis
Polypit Pty Ltd
Yarra Valley Water is currently spending more than $15million annually on new and rehabilitated
sewer assets and is also accepting some $6million worth of developer contributed assets.
At Yarra Valley Water we thought there must be great potential to challenge the status quo when it
comes to sewer design, design standards have been unchanged for 40 years. New sewer design
standards and more up to date sewer products had the potential to save us many thousands of
dollars. A value management study was born!
In 1996 a value management study was carried out to review sewer design standards. From this
study it quickly became evident that the construction of access chambers and their spacing was a
prime area for review. It was found that the average spacing of manholes could safely be doubled in
most cases as current sewer maintenance equipment could easily handle the increased spacing.
We also found the design of the current concrete access chamber had not changed over the last
century. Furthermore current confined space entry requirements make it an expensive exercise
when access is necessary. It was also determined that on average access chambers cost
approximately $1000 per metre lift and in the majority of cases do not need to be used for perhaps
20 years.
Also the cost of constructing manholes is between 10% and 20% of the total construction cost.
Arising from the value management study, two clear objectives loomed large for Yarra Valley
Water to consider, 1) the opportunity to double the spacing of access chambers to suit current
maintenance equipment and 2) to find a replacement for the concrete access chamber.
SAIF-T (which is an acronym for Safe Access Inspection Fitting) was developed by a dedicated
team as a direct result of the value management study and YVW's drive to deliver an efficient water
supply and sewerage business to its customers.
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