Changes

'''Notes:'''

'''Notes:'''

 

#Estimated life cycle costs represent NPV of associated costs in Canadian dollars per squaremetre of CDA ($/m2).

#Estimated life cycle costs represent NPV of associated costs in Canadian dollars per squaremetre of CDA ($/m²).

#Average annual maintenance cost estimates represent NPV of all costs incurred over the time period and do not include rehabilitation costs.

#Average annual maintenance cost estimates represent NPV of all costs incurred over the time period and do not include rehabilitation costs.

#Rehabilitation cost estimates represent NPV of all costs related to repair work assumed to occur every 25 years, including those associated with inspection and maintenance over a two (2) year establishment period for the plantings.

#Over a 50 year evaluation period, average annual maintenance cost estimates for the High Frequency maintenance scenario are 59% and 56% higher than the Minimum Recommended Frequency maintenance scenario for underground concrete cistern and indoor plastic cistern systems respectively.

#Full Infiltration design life cycle costs are lower than Partial and No Infiltration designs due to the absence of a sub-drain to construct, inspect and routinely flush.

#Rehabilitation costs for the indoor plastic cistern system (i.e., replacing the cistern structure) are estimated to be 9.67% of the original construction costs, regardless of the maintenance frequency.

#Rehabilitation costs for Full Infiltration designs are estimated to be 26.4 to 28.4% of the original construction costs for High and Minimum Recommended Frequency maintenance program scenarios, respectively.

#Maintenance costs over a 25 year time period for underground concrete cistern systems are estimated to be 45.8% of the original construction cost for the Minimum Recommended Frequency maintenance scenario, and 89.4% for the High Frequency maintenance scenario.

#Rehabilitation costs for Partial Infiltration designs are estimated to be 19.9 to 21.6% of the original construction costs for High and Minimum Recommended Frequency maintenance program scenarios, respectively.

#Maintenance costs over a 25 year time period for indoor plastic cistern systems are estimated to be 47.7% of the original construction cost for the Minimum Recommended Frequency maintenance scenario, and 98.0% for the High Frequency maintenance scenario.

#Rehabilitation costs for No Infiltration designs are estimated to be 20.2 to 21.9% of the original construction costs for High and Minimum Recommended Frequency maintenance program scenarios, respectively.

#Maintenance costs over a 50 year time period for underground concrete cistern systems are estimated to be 0.918 times the original construction cost for the Minimum Recommended Frequency maintenance scenario, and 1.59 times for the High Frequency maintenance scenario.

#Maintenance and rehabilitation costs over a 25 year time period for the Minimum Recommended maintenance scenario are estimated to be roughly equivalent to the original construction cost for Partial Infiltration and No Infiltration designs (96.2% and 97.8%, respectively), and 1.21 times the original construction cost for Full Infiltration design.

#Maintenance costs over a 50 year time period for indoor plastic cistern systems are estimated to be 1.07 times the original construction cost for the Minimum Recommended Frequency maintenance scenario, and 1.84 times for the High Frequency maintenance scenario.

#Maintenance and rehabilitation costs over a 25 year time period for the High Frequency maintenance scenario are estimated to be 1.32 times the original construction costs for Partial Infiltration, 1.34 times for No Infiltration designs, and 1.67 times for Full Infiltration designs.

#Maintenance and rehabilitation costs over a 50 year time period for the Minimum Recommended Frequency maintenance scenario are estimated to be approximately 1.76 times the original construction cost for Partial Infiltration designs, 1.79 times the original construction cost for No Infiltration designs, and 2.21 times the original construction cost for Full Infiltration designs.

#Maintenance and rehabilitation costs over a 50 year time period for the High Frequency maintenance scenario are estimated to be approximately 2.40 times the original construction cost for Partial Infiltration designs, 2.44 times the original construction cost for No Infiltration designs, and 3.04 times the original construction cost for Full Infiltration designs.