Detailed Assessments & Designs of Onsite Sewage Systems

What is site assessment?

We look at many factors, starting with determining the design sewage flow for the proposed system. To do this we have the client complete our Owner Declaration Form outlining the proposed occupancy and usage of the property.

We then look at the site and consider the following: location of wells, fresh water supplies, breakout points, perimeter drains, property lines. We look at the vegetation and soils, equipment access, surface and groundwater intrusion, rock, distance of site from sand, gravel and topsoil supplies. We analyze the soil composition and permeability while we are onsite.

When we have completed the site assessment we have an understanding of what the constraints are and how severe they are.

Site Assessment & Design Process

The process to assess the site, design, install and certify the installation is as follows:

  1. Client discusses job with CSSi (usually by telephone). CSSi sends the client via email a copy of:
    1. Owner’s Declaration
    2. Letter of Engagement,
    3. CSSi Fee Schedule for Site Assessments and Design
  2. The Client reviews and signs the above documentation and provides a deposit.
  3. CSSi meets client on site for initial overview of site. Client may give CSSi the owner’s declaration, letter of engagement and deposit at this time.
  4. CSSi does the site assessment (including soil work) and the design to determine what type of onsite septic system is appropriate. For residential properties the site assessment and design range from $1,000 to $3,000 depending on the complexity of the site (usually around $1,500).
  5. If there are several options, CSSi will discuss with the client before finalizing a design.
  6. CSSi invoices client for the site assessment, design and filing. CSSi also provides a copy of the design specifications to the client.
  7. CSSi prepares either a quote or an estimate for the installation.
  8. CSSi submits the “filing” and the $200 filing fee to the local health authority. A filing with the health authority is required to obtain a building permit from the municipality. 
  9. Installation of the filed design. Sometimes due to new site constraints, modifications to the design are made during installation. Installation costs can vary depending on the type of system, system constraints, etc.
  10. CSSi starts up and tests the onsite sewage system and records the initial operating parameters.
  11. CSSi prepares and submits to the health authority:
    1. As-build specifications
    2. As-constructed drawings
    3. Operations and maintenance plan (O&M plan), and
    4. Letter of Certification signed by an “Authorized Person”
  12. CSSi invoices the client for the installation
  13. Client receives copy of:
    1. As-constructed specifications
    2. As-constructed drawing
    3. Operations and maintenance plan (O&M plan), and
    4. Letter of Certification signed by an “Authorized Person”
    5. Home owner information about onsite sewage systems
    6. 2 copies of the Acknowledgement page
  14. Client signs and returns the Acknowledgement page.


The soils are the key to a well-functioning onsite sewage system. Typically, 70% of the treatment will take place in the soil. The texture, structure, and permeability of the soil are critical as these factors are used to determine the maximum hydraulic loading rate (HLR) for the soil. A larger hydraulic loading rate will result in a smaller dispersal field.

Soil depth is also a key factor to designing a dispersal field. Treatment in the soil occurs in unsaturated conditions, therefore, the depth of unsaturated soil is key to achieve sufficient treatment. If there is insufficient soil depth to a restrictive layer (bedrock, seasonal high-water table, or massive clay), additional sand will be required to increase the vertical separation. 



CSSi does over a 100 projects per year. In addition, many of our projects come as referrals from ROWP planners and installers. Many other projects come from referrals from satisfied customers.

Challenging Sites

Many of our jobs are for challenging sites. Consequently, with the large number of projects and the degree of difficulty, we have an excellent record in developing cost-effective solutions for challenging sites. Most of the other companies represent a particular type of treatment plant. Therefore, they will install whatever treatment plant they represent even though it may not be the best option for the site. CSSi deliberately does not represent any one treatment plant manufacturer, even though it could be more profitable to do so. We chose to be independent of the treatment plant suppliers so that we can choose the most appropriate system for the situation. 

For more information about our services, please give us a call.

Site Assessments & Design

We provide detailed sewage site assessments and engineer appropriate designs for what you need.

Professional Service & Care

See what our clients have had to say about our sewage system work and our customer service.

Canadian Sewage Solutions Inc

809 Industrial Way

Victoria, BC V9B 6E2


Monday – Friday: 7:30 AM – 4:00 PM
Weekends/Holidays: Emergency Only

Copyright Canadian Sewage Solutions Inc 2018