Water plant filter, estimate of annual maintenance costs

[Engingguy]

Hello,
I am doing an alternatives analysis of replacing a municipal water plant filter and clarifier vs. replacing a filter and repairing an existing clarifier. What would be a reasonable estimate of annual maintenance cost as a percentage of initial cost, and a source for that number? I suppose I could get some value from the vendor but I don’t necessarily trust numbers from vendors.

Thanks, engingguy

 

[ashtree]

A couple of questions for a start are necessary to determine what it is you want.

Are the filters the same in both options?- if they are then only the clarifier component is different.
Does the owner of the installation have any information on the maintenance costs of the existing clarifier?
Does the repair of the old clarifier substantially change the maintenance costs? For example are you replacing painted structures below water line with stainless steel.
Are the old and new clarifiers similar style and technology?- annual costs for ongoing maintenance may be very similar if they are similar styles etc.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[Engingguy]

The filter is the same in both options, and revenues generated are the same in both cases as they make their permitted GPD either way. The existing clarifier is very different from the potential replacement, and we have no good records of maintenance of the existing one. I’m just looking for a reasonable value for annual maintenance money to be set aside. I am seeing 1 to 3 percent for long lived equipment, so am using the middle value of 2% as a placeholder until I get another number. Repair of the existing clarifier doesn’t change the annual maintenance costs but will defer installing a new one. Pretty much at present something is fixed when it breaks.
I suppose this is more an economics and asset management problem than an engineering problem. The Big Engineer alone knows what the actual maintenance costs will be. I am looking for an accepted industry figure as a percentage of initial cost to be put into a maintenance fund.
Thanks, engingguy

 

[bimr]

The EPA has a number of reports, some of which are old. Take one of their reports and update the unit costs.

EPA

Google

 

[Engingguy]

This is useful, thanks.
Engingguy