Galt WWTP Clarifier Renewal Program Richard Pinder Region of Waterloo, Senior Project Engineer Thomas Uda GHD, Asset Management Consultant CNAM 2014 Conference Toronto, Ontario May 20-23, 2014

Background Information Region of Waterloo has 13 WWTPs, consisting of 20 primary and 36 secondary clarifiers Pilot a clarifier renewal strategy at the Galt WWTP for five primary and six secondary clarifiers

Objectives Make informed decisions related to maintenance and capital programming activities Justification of yearly expenditures on maintenance and renewal Develop a program we could use

Galt WWTP Clarifiers Primary Clarifiers Secondary Clarifiers Plant A (4 x 18.3m) Plant B (1 x 25m) Secondary Clarifiers Plant A (4 x 22.86m) Plant B (2 x 31m)

Project Steps Understanding the current state of maintenance planning activities Improving the Current State Prioritization of Maintenance (Risk Profiles) Lifecycle Costing (three options considered) Recommendation and Overall Cost Summary

Understanding the Current State of Maintenance Understand the existing failure modes of the clarifiers Gear drive typically fails from bearing wear and improper lubrication Other assets are structural elements that fail due to overall wear, rusting, or corrosion Use failure modes to identify gaps in clarifier maintenance activities

Improving the Current State: Maintenance Program Development of strategies based on criticality to reduce risks and prevent unexpected failures Condition-based Time-based Run-to-failure Key step: Input from operators

Improving the Current State: Maintenance Program Gear drive failure is a main source of reactive maintenance Increase frequency for changing oil and checking gear drive for wear Inexpensive and less critical components follow a run-to-failure strategy Scum heater and level transmitter

Improving the Current State: Maintenance Program Current asset hierarchy Recommended asset hierarchy

Prioritizing Maintenance: Developing Risk Profiles Risk depends on probability and consequence of failure Condition assessment = physical mortality

Prioritizing Maintenance: Developing Risk Profiles Plant B clarifiers are the highest priority (lack of redundancy compared to Plant A)

The Lowest Cost Approach: Lifecycle Costing The goal is to perform the right maintenance and renewal activities at the right time Three approaches to maintenance and renewal are considered 50 year lifecycle

The Lowest Cost Approach: Lifecycle Costing Option 1: Minimal preventive maintenance Option 2: PM Program with scheduled asset replacement Option 3: Similar to Option 2, but refurbishments are performed to extend the effective life of the asset

The Lowest Cost Approach: Lifecycle Costing Capturing Consequence Costs Repair or replacement cost Cleanup Extra labour Contingency Plans Option 1: Highest Consequence Costs Option 2 and 3: Benefit from timing the renewal of assets in groups

Option 3 (PM Program with refurbishment) results in lowest lifecycle cost

The Lowest Cost Approach: Lifecycle Costing Example of Yearly Costs

The Lowest Cost Approach: Lifecycle Costing Costs (run-to-failure vs scheduled renewal)

The Lowest Cost Approach: Lifecycle Costing 12 Year Outlook

Conclusions Operator involvement is key to developing and implementing a renewal plan Renewal Plan assists in focusing resources on critical and high risk assets Risk can be quantified in dollar values by estimating the cost of the consequence of failure

Conclusions The Region’s current maintenance strategies were in line with Option 3 (preventive maintenance and refurbishment strategy). Renewal plan justifies this approach compared to other maintenance approaches Prioritization of assets was established (PC#5, SC#5, and SC#7)

Next Steps The renewal plan is an ongoing process; refurbishment and renewal intervals are to be updated The recommendations from this project contribute to the Region’s overall Capital Improvement Plan Similar strategies are planned to be implemented for clarifiers at other Region WWTPs

Questions? Contact Us: Richard Pinder Region of Waterloo RPinder@regionofwaterloo.ca Thomas Uda GHD, Asset Management Consultant thomas.uda@ghd.com