Updated September 2026
BC Septic Regulations: Do You Need a Permit in the Cowichan Valley?
In BC you don't pull a permit for a septic system — under the Sewerage System Regulation, an Authorized Person (a Registered Onsite Wastewater Practitioner or a Professional) files it with Island Health instead. Three steps for a Cowichan Valley property: we evaluate your soil and site, we file the design with Island Health before any construction starts, and we submit the Letter of Certification once the system is built — until then it can't legally be used. We handle that filing for you across the Cowichan Valley Regional District.
Updated September 2026
An Authorized Person files the system with Island Health as part of septic system installation.
Filing, not a permit
Most residential systems now go through the Sewerage System Regulation as a filing. We submit the design to Island Health before work begins, then file the Letter of Certification once the system is built and inspected. Until that certification is in, the system can't legally be used.
Who can file — ROWP or Professional
Only an Authorized Person may design, install, and file a system — either a Registered Onsite Wastewater Practitioner (ROWP) registered with ASTTBC, who covers Type 1 and Type 2 systems, or a Professional such as an engineer, who can cover any type. Our installers are ROWP-registered, and we bring in an engineer when a site calls for one.
Island Health and the Cowichan Valley Regional District
Your filing goes to Island Health, the health authority for Vancouver Island. The Cowichan Valley Regional District can add requirements on top — covenants, watershed protection near Shawnigan Lake, or coordination with a building permit — and we confirm which apply to your property at the assessment.
Maintenance is part of the rules
Every Letter of Certification comes with a maintenance plan, and a treatment system needs regular servicing by a qualified person. We set that plan up with you. You have to keep to it, and it's also the cheapest way to look after the system.
Repairs and replacements need a filing too
It's not just new builds. Replacing a tank, moving a drain field, or swapping a failed system all go through the same filing with Island Health before work starts. A like-for-like repair inside the tank — a baffle or a lid — usually doesn't, and we'll tell you which side of the line your job sits on at the assessment.
| System / situation | Who handles it | What's filed with Island Health |
|---|---|---|
| Type 1 (tank + drain field) | ROWP or Professional | Design filed before build; maintenance plan with the Letter of Certification |
| Type 2 (treatment system) | ROWP or Professional | Design filed before build; maintenance plan with the Letter of Certification |
| Type 3 (sensitive sites) | Professional | Design filed before build; maintenance plan with the Letter of Certification |
How the filing process works
- 1
Assessment & soil evaluation — We evaluate the soil and the site to work out which system type your property needs.
- 2
Design filed with Island Health — We design the system and file it with Island Health before any construction begins.
- 3
Letter of Certification — Once the system is built and checked, we file the Letter of Certification that makes it legal to use.
How long the filing takes
Island Health reviews the filing before construction can begin, so it's worth building the review time into your plans — especially if you're coordinating with a building permit or a sale. We file as soon as the design is ready, keep the application moving, and only book the dig once the filing is in place.
What the filing costs
There's no separate permit fee for you to budget around. The design, the filing, and the Letter of Certification are all part of the installation price on our quotes, so the number you see is the number that gets your system legal. The cost guide breaks down typical installed prices by system type.
For pricing, see the septic cost guide. We design and file new and replacement systems with Island Health across the Cowichan Valley, including Duncan, Shawnigan Lake, Cobble Hill, Mill Bay and Maple Bay.
Not sure what your property needs? Book a free assessment — we'll confirm the system type and handle the Island Health filing.