Ontario · Costs · 2026
Three quotes, same yard: $24,000, $31,000, $39,000. Why?
Nothing shakes a homeowner’s trust like three wildly different prices for what sounds like the same hole in the ground. Most of the spread has boring, checkable explanations — and once you can read a quote, you can tell a fair price from a fishing trip.
The short version: quotes differ because contractors are pricing different assumptions — about your soil, your water table, the system class, disposal of the old bed, and how much risk they are absorbing. The fix is not more quotes. It is knowing your own numbers first.
FREE 2026 PDF
Homeowner’s Guide44 pp.
Costs, permits, contractor vetting, and the owner-builder path — updated for the 2026 Building Code.
No spam. Straight talk from a builder.
1 Something’s wrong2 What it costs3 The permit4 Who designs it5 The paperwork6 Approval
The part nobody tells you
Designers charge $800–$2,000 just for the paperwork in these quotes.
Ontario law lets you do that part yourself, on your own property. OntarioSepticDesigner.ca turns your answers into the same 26-page package the township clerk sees every day — calculations, drawings, forms, all of it.
The six legitimate reasons prices differ
1Soil assumptions — one bidder assumes T=15, another protects himself with T=30. That alone can double the bed and add $8,000–$12,000. T-time explained here
2Conventional vs raised — if high water is even possible, a careful bidder prices the raised bed and its 20 loads of sand; an aggressive one prices the cheap case and change-orders you later
3What happens to the old system — pumping, crushing and burying the old tank versus excavating and hauling contaminated bed material off-site are very different lines
4Who does the paperwork — design, drawings and permit filing add $800–$2,000 when bundled in, and some quotes quietly exclude it
5Access and trucking — tight lots, long carries, wet ground, distance to the sand pit. Rural trucking is real money
6Season and backlog — a crew booking eight months out prices differently than one with a gap in three weeks
The spread that is NOT legitimate
Identical assumptions should produce similar prices. When one quote is $15,000 over the others with the same system class, same bed size and same inclusions, you are usually looking at a “busy price” — a bid the contractor half-hopes you refuse. And a quote dramatically UNDER the pack with vague inclusions is the more dangerous one: the missing money comes back as change orders once your yard is open and your leverage is gone.
The five questions that expose a vague quote
What T-time is this priced on? Conventional or raised — and what happens to the price if the test holes say raised? Is the old system’s removal included, and to where? Who does the design, drawings and permit — and is that in this number? Is HST in? Any bidder who cannot answer those in writing has not priced your job — he has priced a job.
The $18,950 line that never appears on a quote
A real worked example: 3-bedroom bungalow, conventional bed. Tank supplied and set, pipe, stone, fabric, one day of machine and labour, permit allowance — $13,049 with HST. The same job quoted at $32,000. The gap is design fees, markup, and labour you may not need to buy.
Two minutes on the free checker shows the numbers your own lot generates — daily flow, tank size, risk level — before anyone quotes you.
Walk in knowing your own numbers
Everything in reason 1 and 2 — the biggest swings — is knowable before you invite anyone over. Dig your test holes, read your water table, and run the free check: it produces your flow, your bed size range and a planning cost for YOUR soil. Quotes stop being mysterious the moment you can compare them against your own baseline — and bidders sharpen their pencils when they see you have one. The full picture of what a fair job costs is on the replacement cost page, and if you are building new, new-system costs run differently.
Quote questions, answered straight
How many septic quotes should I get?
Three, from contractors who each saw the lot and your test-hole data. Ten quotes on different assumptions teach you nothing; three on the same assumptions teach you everything.
Should I take the lowest quote?
Take the lowest COMPLETE quote — written inclusions, named system class, stated T-time, disposal included. A cheap vague number is the most expensive thing on the table.
Why did my neighbour pay half what I was quoted?
Different soil, different year, different system class — or a raised bed versus conventional. Two lots a road apart can legitimately differ by $15,000. Compare T-times before comparing invoices.
Can I cut the quote down by doing part myself?
Yes — the paperwork is the classic owner move ($800–$2,000 saved), and some owners also act as their own installer and hire the machine by the day.
Get your numbers before you get quotes
The free 2-minute check turns your bedrooms, soil and water depth into a bed size and planning cost — your private baseline for every bid that follows.