Schedule ‘B’ Municipal Class Environmental Assessment Potable Water Storage

Posted on: May 28, 2018

Town Meeting: Phase 2 Status Update

J.L. Richards & Associates Limited
Sarah Gore, P.Eng., Project Manager

Sources: smithsfalls.ca – PDF
www.jlrichards.ca

Town of Smiths Falls Water System

 

Purpose of this Study

Phase 1 Problem/Opportunity Statement

“The Town of Smith’s Falls owns and operates a communal potable water supply system for the Town, including the Township of Montague (Atironto Subdivision), that generally consists of a new (2010) surface water treatment plant, an elevated potable water storage tank and a dedicated distribution system. While the system has been operating in accordance with all applicable legislation and is achieving all required water quality standards, the Town does not currently meet potable water storage requirements as defined by the Ministry of the Environment and Climate Change. Notwithstanding this, the Town’s current elevated potable water storage tank, at 90 years old, is in need of refurbishment or replacement and therefore the Town is in need of a solution that will address water storage constraints now and for the next 20 years and beyond.”

  • System is generally achieving all required water quality standards
  • System does not meet potable water storage requirements as defined by the MOECC
  • Approx. 4 hours available during current maximum day demands
  • Growth pressures in the Town’s Official Plan
  • Elevated potable water storage tank (90 years old) is in need of refurbishment or replacement for compliance with the National
  • Building Code and Ontario Building Code
  • A potable water storage solution is needed for the next 20 years and beyond

 

Overview of the Schedule ‘B’ Class EA Process

Population and Growth Projections (20-Year Period)

Population and Water Demand Projections

Build-out Approach:

  • 2010 WTP was designed with provisions for a build-out capacity of 18,000 m3/d (after upgrades)
  • To maintain continuity, potable water storage build-out review will be based on a projected maximum day demand of 18,000 m3/d

 

Storage Projections

Existing Potable Water System Constraints

Identification and Initial Screening of Alternative Solutions

Option 1: Do Nothing

Concept

  • The ‘Do Nothing’ alternative implies maintaining status quo
  • Generally carried forward as a baseline for review of other alternatives
  • This option considers rehabilitation and continued operation of the existing elevated tower, which includes full removal and replacement of existing lining systems, in addition to other structural modifications to make the tank compliant with the National and Ontario Building Codes

 

Key Considerations for Evaluation

  • Does not address storage requirements as defined by the MOECC
  • Rehabilitation requires significant tower shut-down leaving the Town to rely solely on the Water Treatment Plant and High Lift Pumps to service demand
  • Cost is significant – limited value in rehabilitating to secure a fraction of the required water storage
  • Marginal improvement to tank’s lifespan, but still possible that frequency of unplanned work and costly repairs will increase over time given the tank’s age

 

Option 2: Decommission Existing Tower and Construct New Elevated Tower

Concept

  • Construction of a new elevated storage tank at three potential locations within the Town as well as a new vacuum priming system for the existing High Lift Pumps to maximize the WTP reservoir’s available water storage

 

Key Considerations for Evaluation

  • Addresses potable water storage requirements as defined by the MOECC
  • Improves operational flexibility
  • Significantly increases fire flow storage volume, improving the reliability of the system to fight a fire and continue to service demands
  • Maximizes the WTP reservoir’s available potable water storage
  • Potential commercial and residential impacts during construction and operation of a larger tower
  • Initial cost of new elevated storage tank is significant

 

Option 2: Potential Locations for Future Storage

  • Initial Screening Requirements:
    • Town-owned land or leased
    • Located north of the river to avoid significant watermain upgrade
    • Lot larger than 2 ha
    • Compatible land use and zoning
  • 8 locations (Sites A-H) further narrowed down based on a review of land attributes, existing development, proximity to trunk water main, adjacent lands, etc.
  • 3 locations carried forward to detailed evaluation (Sites ‘B’, ‘D’ and ‘E’)

 

Opinion of Probable Costs

*Class ‘D’ Opinion of Probable Costs for this Class EA:

  • Work Definition: A description of the intended solutions with such supporting documentation as is available
  • Intended Purpose: To aid in the screening of various options proposed prior to recommending a preferred solution (not intended to establish or confirm budgets)
  • Level of effort is limited and expected accuracy could range from -30% to +30%
  • Opinion of Probable Costs reflect a ‘2018’ dollar value

 

Evaluation of Servicing Alternatives

Identification of Preferred Alternative

Project Schedule and Next Steps

  • Obtain and evaluate public, stakeholders and agency comments and confirm preferred solution
  • Post Schedule ‘B’ Report and advise stakeholders and public
  • Issue Notice of Completion
  • Following 30-day public review period, finalize Class EA
  • Commence preliminary design of preferred solution