Septic System FAQs
Straight answers to the questions we hear most about septic systems in Southern Ontario. If your question isn't here, get in touch — we'd rather look at your specific property than guess.
There's no single price — cost depends on the system type, the size and design flow, the site conditions, the amount of excavation and material, and whether advanced treatment is needed. Rather than quote a misleading number online, we look at the property and give you a real figure. The best first step is to request a quote.
The installation itself varies with the system, the site and the weather. The bigger variable is the approval timeline, which the municipality or approval authority controls and we don't. Once we've evaluated the property we can give you a realistic schedule.
The property address, what you're building or replacing, and any site plan or existing septic design you have. Our quote form walks you through the useful details and lets you attach files.
Septic (sewage) systems in Ontario fall under the Ontario Building Code, and installing or replacing a system generally requires a permit. The approval authority and exact requirements vary by municipality. We prepare the required drawings and documentation as part of the project. We don't guarantee approval or specific timelines.
Yes — design and installation are our core business, and keeping both under one roof is the main reason property owners work with us.
Septic system design is carried out by qualified designers under the Ontario Building Code. Slegh Septics is a BCIN-registered septic system designer and installer.
A site evaluation looks at the property and proposed development — soil conditions, available area, elevations, setbacks, wells, watercourses and boundaries — to determine what system the site can support.
The leaching bed (also called the septic bed) is the part of the system where treated effluent is dispersed into the ground through distribution piping and bed materials such as septic sand and stone. Different people search for it as either a 'leaching bed' or a 'septic bed' — they refer to the same thing.
A tertiary (advanced) treatment system treats effluent to a higher standard before it's dispersed, which can allow a smaller dispersal area or make a difficult site workable — depending on the property and approval requirements.
It's typically considered on constrained or wet lots, difficult soils, or where the design flow is high. Whether one is required or beneficial is determined during design based on your specific property.
It depends on the system type, the daily design flow and the soil. Advanced treatment can reduce the footprint on tight lots. The design determines the space required for your property.
Often, yes. Tight, wet or high-flow sites sometimes call for an advanced or tertiary approach. We'll tell you honestly what the site can and can't support.
Yes. Slegh Septics is a qualified and certified installer for Waterloo Biofilter, Ecoflo and Eljen systems. Which system suits a property is determined during design, based on the site and the daily design flow.
Sometimes — it depends on whether the existing system was sized for the increased flow and still meets requirements. An addition can trigger the need for an upgrade or replacement. We assess the specific system and property.
Age, overloading beyond the design flow, damage, failed inspections and changing property use are common factors. We assess the specific system rather than diagnose online.
Yes — new homes, custom homes, severed lots and rural building lots are a core part of our work. It's best to involve us before construction starts.
Yes. Commercial and higher-flow systems are a core part of our work, from design through installation.
Yes. Many projects come through custom builders, developers and general contractors who need one accountable septic contractor for design, permits and installation.
We serve property owners, builders and contractors throughout Southern Ontario. We publish dedicated area pages only for regions we genuinely serve.
Yes — excavation and site work are handled in-house as part of the installation, which keeps the whole project with one crew.
Yes, where the design requires pump-assisted distribution. Pump chambers, dosing systems, alarms and controls are specified during design.
Yes — appropriately sized concrete tanks, for new systems and as replacements.
Our core business is design, installation and replacement. Septic pumping and clean-out isn't a service we currently advertise.
Still have a question?
Tell us about your property and project — we'll give you a straight answer and the right next step.