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New septic system installation on lots with no sewer connection
Design, filing and construction for lots with no sewer connection.
A new septic system on a lot with no sewer connection is designed by an Authorized Person, filed with Island Health before excavation, then certified within 30 days of completion. Soil depth, slope and a 30 m separation from any domestic well decide whether the result is a Type 1, Type 2 or Type 3 system.
Every new build outside the six small sewer service areas of the Regional District of Nanaimo needs its own treatment and disposal system. What that system looks like is not a matter of preference. The ground sets the limit, and the design has to show the ground can take the load before anything is dug.
No two lots price the same. What moves the number is the effluent standard the soil forces, the type and area of disposal field, depth of excavation, whether pressure distribution or a raised sand-based field is needed, and how close a truck can get. Design and filing are quoted separately from construction.
What the site assessment looks for
Soil depth to a restrictive layer, slope, drainage, and the seasonal signs of a high winter water table, along with the position of every well, property line, building and water line. Island Health's published subdivision standards set 30 m from a well, 30 m from the natural boundary of tidal and non-tidal water, 3 m from a parcel boundary, and a minimum soil depth of 0.46 m to 1.2 m depending on soil type, slope and water supply. Those distances are what usually decide where a field can go, not where a field would be convenient.
What actually separates Type 1, Type 2 and Type 3
The Sewerage System Regulation classifies systems by effluent quality, not by brand of equipment. A Type 1 system is treatment by septic tank alone. A Type 2 system must produce effluent consistently under 45 mg/L total suspended solids and under 45 mg/L five-day biochemical oxygen demand. A Type 3 system must reach under 10 mg/L on both, with a median fecal coliform density below 400 CFU per 100 mL. Higher treatment lets a smaller or shallower disposal area do the same work, which is why a tight lot often ends up at Type 2.
Who is allowed to design and file
A Registered Onsite Wastewater Practitioner registered with ASTTBC may file Type 1 and Type 2 systems under 9,100 litres per day. A Professional — an engineer or geoscientist — may file any type and higher flows. A property owner may build a system only under the supervision of an Authorized Person. Island Health states plainly that it does not approve the design and does not review filings for technical merit; responsibility for the system sits with the Authorized Person who signs it.
System types quoted
Type 1 gravity system
Septic tank and gravity disposal field, where soil depth and slope allow effluent to move without dosing.
Pressure distribution
Effluent dosed evenly across the field, used where soil is shallow or the usable area is tight.
Type 2 treatment
Treatment to under 45 mg/L before the field, which reduces the disposal area a site has to find.
How a new system reaches certification
- 1
Soil logging and site survey — test pits, soil depth, slope, and every setback measured on the ground.
- 2
Design and sizing — effluent standard, field type and field area set by what the soil log will support.
- 3
Record of Sewerage System filed — plans, specifications and a scaled site plan lodged with Island Health before excavation.
- 4
Construction — tank, distribution and disposal field built to the filed design.
- 5
Letter of Certification — filed within 30 days of completion with an as-built diagram and a maintenance plan.
What the ground here does
Nanaimo Lowland ground is layered rather than uniform. A Geological Survey of Canada model of the lowland describes Quadra Sand, over 75 m thick in places and the most important water-bearing unit, sitting beneath Vashon Drift till up to 30 m thick that acts as a confining layer, with a clayey silt aquitard of the Cowichan Head Formation below. What that means on a given lot is that soil depth can change across a single property, and a test pit at one corner does not describe the other. A provincial groundwater survey covering South Wellington noted small-lot density where some wells sit closer than the 30 m separation distance to a septic field.
In practice
- Situation
- A two-acre lot east of Cedar Road, building a new house, with a drilled well near the road frontage.
- Complication
- The only level ground sat within 30 m of the well, and the soil log hit dense till at 0.7 m.
- Resolution
- The disposal field moved uphill behind the house and the design stepped up to a Type 2 standard, which reduced the field area enough to clear both the well separation and the 3 m parcel boundary.
People also ask
Is a septic permit required in the Regional District of Nanaimo?
Not a permit. A septic system is filed, not permitted, under the Sewerage System Regulation. The Regional District of Nanaimo does require the filing as a supporting document on a building permit application for any property not connected to a municipal system.
Can a homeowner build their own septic system in British Columbia?
Yes, but only under the supervision of an Authorized Person. The design and the filing still have to come from a Registered Onsite Wastewater Practitioner or a Professional.
What happens after the system is built?
A Letter of Certification goes to Island Health within 30 days of completion, with an as-built diagram and a maintenance plan for the system as built.
Does Island Health inspect the installation?
No. Island Health checks that a filing meets minimum submission criteria. It does not inspect the work, approve the design, or review the filing for technical merit.
Two things usually settle before a design starts — a system inspection, typical cost drivers, the Island Health filing process and septic service in Cedar.
Find out what the ground will take.
Free site assessments across Electoral Areas A, B and E and the District of Lantzville.