Maintenance and Repairs

November 1, 2023 Published by Golden Horseshoe Chapter - By Tyler Brook, Matt Foster

Buried Services: Out of Sight, Not Out of Mind

From the Volume 17, Fall 2023 issue of the CCI GHC Condo News Magazine

Often when condominium owners think about long-term capital planning the big-ticket items spring to mind are some of the most visible: windows and doors, wall cladding, the asphalt pavement roadways, or maybe replacing that tired gazebo. But hidden below ground are some other high-value items: the Corporation’s buried services, including domestic water main systems and storm and sanitary sewers. These are important systems to be mindful of for long-term capital and technical planning.

WHAT ARE BURIED SERVICES?

For this article, we focus on buried water management services, which can generally be thought of as systems that bring fresh potable water onto a site and then remove waste or storm water from a site.

Domestic water supply systems typically consist of buried pipes which connect to the city or municipal water mains, and deliver water to the building, or to the townhouse units throughout a site. Often these systems include a larger main which then has smaller service lines that take the water from the main to the individual units. If you compare a water main system to the anatomy of a tree, the main is the trunk, and the service lines are the branches. These systems can include other components such as water meters, pressure reducing valves, strainers, and backflow preventers, depending on the requirements of the municipality.

While it is often the local municipality’s responsibility to maintain water meters, these other components are usually the responsibility of the condominium to maintain and eventually replace. This maintenance may include yearly inspections as is the case for backflow preventers. At sites which do not have interior mechanical rooms, typically townhouse sites, a below-grade concrete structure or chamber, is required to house these components such that they can be accessed and serviced.

Some municipalities may require these components (and their related chambers) to be installed retroactively if they were not installed at the time of original construction. A retroactive mandate like this can be sprung on a condominium without notice, creating a significant capital expenditure that the condominium has little time to save for.

There may be sections of buried pipe that are the responsibility of the individual unit owners where the smaller service pipes branch off to the individual units, although each corporation’s declaration should be consulted for such details of responsibility.

Buried sanitary sewer systems typically consist of buried pipes that connect to the building or individual units and transport sanitary waste off the site, connecting to the local sanitary sewer systems. These systems are primarily gravity-fed, but sometimes include pumps or ‘lift stations’ to supplement the transport off site.

Storm sewer systems consist of pipes that collect surface runoff water from landscaped and paved areas of a site via catch basins, and in some cases are connected to collect rainwater from roofs or water from foundation drainage systems and transport it off site to local stormwater sewer systems. In some cases, on-site stormwater retention tanks or ponds are used to manage the flow of stormwater during high volume rain periods.

As building science engineers we have always been aware of the need for maintenance and repairs of buried services. We often find that these essential systems tend not to experience significant issues for some time after original construction but do require increasingly significant repairs as sites continue to age, in our experience, once they hit about thirty or more years.

WHAT ISSUES CAN OCCUR?

Typical issues at buried water mains include leaks and breaks. Corrosion of the pipes or settlement of soil around the pipes can occur over time and lead to breakage or leakage, resulting in high water bills, or full water main breaks causing flooding and subgrade washout issues as well as interrupting the supply of water, that require costly emergency repairs. As water mains are under pressure, these effects are often experienced without warning and can be quite catastrophic when they occur.

With buried sewer systems, the issues are often more subdued and with indicators. Blockages can be caused by unit owner activities as well as cracking of pipes and subsequently roots growing inside pipes and blocking flow. Blockages can lead to other issues such as backing-up into suites at sanitary systems. At storm drainage systems it can cause poor site drainage leading to issues such as leakage through foundation walls or slip and fall concerns at ponding areas in winter. Older sewer pipe systems may have been constructed with clay pipes rather than pre-cast concrete or PVC which more modern systems use. Clay, generally a brittle and less robust material, can be more prone to breaks or collapses in the sewer pipes.

Another common issue is the pipes being unsupported within the ground due to leakage ‘washing away’ soil around the pipes or due to settlement of the bedding soil causing the pipes to sag, crack or break with sometimes drastic issues requiring emergency repairs or replacement. A localized break in the sewer pipe can also cause surrounding soil to infiltrate and be displaced by the pipe, where the sewer acts as a sort of ‘conduit’ that carries soil away. Soil displacement can lead to further pipe damage, often undertaking a general removal and replacement approach of their full domestic water supply systems rather than ‘rolling the dice’ on another year with aging systems after years of ongoing water main breaks. This type of approach is not taken lightly as it is often quite expensive, but if issues are ongoing a general replacement project can be the correct thing to do.

From a capital planning and a technical perspective, it makes sense to plan for eventual replacement of domestic water supply systems at the same time as replacement of site roadways and pavements as the pipes often run below these areas. This avoids costly repairs to pavement as part of a water main project since the roadways would be removed for replacement at the same time. There would likely be savings due to economies of scale as well, particularly in comparison with a local repair approach.

A challenge that Corporations sometimes encounter when faced with a major water main replacement project is lack of proper reserve funding. Given the somewhat unknown and concealed nature of buried systems, it can be difficult to accurately predict a time for general replacement. One site might experience frequent breaks or issues at the 30-year mark, while a similar neighbouring site might not have significant issues 50 years out. Scheduling for periodic and escalating local repair allowances can help to hedge against the risk of requiring significant funds for a general replacement project, but also budgeting for eventual general replacement could be considered the most prudent approach. While this latter approach has not previously been considered or planned for at older sites in particular, we are increasingly finding that general replacement is no longer an exception, rather it is becoming commonplace.

With prudent and conservative capital planning, condominiums can be as prepared as possible by starting to reserve for a large buried-service replacement project from ‘day one’ such that over the long-term funds can be adequately allocated. On the other side of the coin, at older sites where a more localized repair approach was previously adopted, and then a switch in strategy to general replacement was undertaken as the site aged and repairs escalated, are now experiencing financial challenges and tough decisions. In this latter case, significant funds may need to be allocated in relatively short order, through increases to reserve fund contribution levels, special assessments, taking on a loan, or some combination.

Further complicating reserve fund planning, as mentioned above, the governing Municipality can also retroactively mandate new infrastructure to be added to private water mains systems, such as installing a backflow preventer and a related chamber to house it. These mandates can be enforced with little notice, which can create an immediate shortfall in the current reserve fund plan. Working closely with your reserve fund engineer to form a solid plan is essential to getting this type of project completed.

To help develop the most accurate capital plan regarding buried services, repair logs should be maintained and that information shared with your capital planning engineer to be considered during updates to the reserve fund study. On a newer site it may seem easy to think of a large project of this nature as a problem for the future, however, to avoid future spikes in funding requirements the importance of planning ahead cannot be understated. The same principle can be applied to all long-term capital planning items.

WHATS INVOLVED IN REPLACEMENT?

Replacement of buried infrastructure is often completed in one of two different ways.

Firstly, would be to leave the existing infrastructure in place (and servicing the site), while a new system is installed essentially parallel to the existing. Once the new system installation is complete, it is commissioned and a ‘change over’ is completed at all the connection points. This involves connecting the ends of the new main to the existing City connection and tie-ins to any branch or service lines. The original service is then decommissioned which usually involves filling it with grout to prevent it from collapsing or causing wash-out in the future. The benefit of this method is that which in turn can lead to further soil displacement, creating a potential cyclical issue. Above grade, this soil displacement can lead to the formation of “sinkholes” or damage to other infrastructure that might be located above (such as watermains, gas lines, electrical conduits, etc.). Similar soil displacement issues can happen around catch basins if the pre-cast ‘moduloc’ rings supporting metal grates are damaged.

HOW TO ASSESS?

Assessment of buried systems is somewhat limited by the concealed nature of being located below ground, however, is important and available. Assessment can help uncover potential issues or provide a preliminary condition evaluation to develop maintenance regimes to keep systems functioning well. Assessment of sewer systems can be done via camera scoping of the sewer pipe systems to look for blockages, cracks, low spots in the pipes or other issues. This video camera scoping can be completed during periodic flushing or cleaning of sewer systems as typically contractors doing this work offer these services. During flushing or camera scoping the sewers are accessed via manholes, catch basins, or other clean-out locations.

Assessment of domestic water supply systems is not so straightforward as the pipes are within a “closed” system that are under high water pressure. A water main does not have features that make it readily accessible such as manholes or clean-outs that sewer systems have, so a camera scope is not practical to complete. One form of assessment for domestic water supply systems is digging test pits to expose sections of the pipe for visual assessment.

Typically, the results of this type of assessment are fairly limited as a test pit only shows one section of the pipe and may not be representative of overall conditions. The cost of conducting a test pit to gain potentially limited results should also be carefully considered. Assessment can and should be completed at times when localized repairs are being completed. When a water main break is being repaired, the opportunity should be taken to assess the exposed portion of remaining pipe within the repair excavation as well as reviewing the inside condition of the pipe where possible.

HOW TO PLAN?

Corporations’ reserve fund studies should include consideration for repairs and often replacement of buried services. Typically, significant repairs are not required at sites until perhaps the 20 or 30-year mark, although of course will vary from site to site based on initial installation and maintenance performed over the years. As repairs start to become necessary, they often occur at a greater rate and cost than in earlier years. It is prudent to plan for repairs as a site ages to help offset the often sudden or somewhat unknown nature of failures to these buried and concealed systems. Consideration should also be given to increasing allowances for repairs further as sites age. Since reserve fund studies are updated relatively frequently (every 3 years), any issues at these systems can be taken into account and adjustments made to ongoing or future allowances for repairs.

While planning for repair allowances is prudent, consideration should in particular be given to planning for eventual full or significant replacement of domestic water main systems, especially at townhouse sites which usually have long lengths of piping. There can come a time when water main breaks and related maintenance become too frequent or expensive such that a more general replacement approach becomes warranted for both the financial stability of a Corporation as well as the convenience of reliable water supply at the site. As capital planning engineers we have observed a trend in recent years towards Corporations more significant cost is not incurred to put temporary infrastructure in place. The difficulty with this approach is that installing a new system parallel to the existing may be challenging depending on the clearances to existing infrastructure that is to remain. For installation of new water mains, this includes maintaining proper clearances from sewer pipes, manholes, catch basins, etc. On sites with limited spaces this can be especially challenging.

The second approach involves installing temporary bypass services. Afterwards, the existing service is removed, and the new service is installed in generally the same location/ layout. The ‘cons’ of this method are that it can be costly to set up. For water main replacements, temporary bypass installation involves installing pipes above grade that run across lawns, sidewalks, roads, etc. At vehicle or pedestrian crossings, temporary ramps or covers must be installed over the pipes to protect them. This creates additional inconvenience and potential site hazards for residents, which is usually otherwise minimized with the first approach mentioned above. The benefit of this approach is that, as long as the original pipe was installed with proper clearances, the installation/ layout of the new pipe is a more straightforward procedure and there is no need to decommission the old pipes as they are removed.

It should be appreciated that regardless of the approach taken, there will be site and service disruptions, which cannot be avoided, which residents should be made aware of before a project starts to help set related expectations.

While keeping a condominium’s buried services in good repair may not be the flashiest item on a Corporation’s to-do list, it certainly is one of the important ones. Out of sight should not be out of mind.

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Tyler Brook is a Senior Capital Planning Engineer at Brown & Beattie Ltd. responsible for the technical assessment and financial planning analysis involved in conducting and overseeing countless Reserve Fund Studies and Performance Audits throughout the GTA and southwestern Ontario.

Matt Foster is a Managing Engineer with the Construction Review and Contract Administration team at Brown & Beattie Ltd. Matt primarily services GTA West including Peel, Halton, and Hamilton Regions. Matt is responsible for preparing technical specifications, and the subsequent review of the execution for related building envelope and infrastructure restoration projects. Brown & Beattie Ltd. provides professional services and expertise specializing in building maintenance, restoration, improvement and sustainability by listening to client objectives and clearly explaining technical issues. We assist our clients in achieving useable plans and sensible results.