Regulation and Program

The Provincial Regulation

The Sewerage System Regulation (SSR) applies to all smaller onsite wastewater treatment systems, including those for houses, small businesses and even small communal systems.

Compared to the previous Sewage Disposal Regulation, the SSR represents a significant change in approach. Responsibility for the proper design and installation of onsite systems has been transferred from Health Authorities toAuthorized Persons’ as defined by the SSR. Now, design, installation, repair and maintenance of onsite wastewater systems must be performed by an Authorized Person. An Authorized Person is required to certify that systems are constructed in compliance with the SSR. Health Authorities no longer issue permits for sewerage system construction.

The enactment of the SSR in 2005 also brought new responsibilities for the owner of a sewerage system. It is the responsibility of the homeowner to ensure sewage is discharged to a sewerage system that is constructed and maintained in accordance with the regulation … and must ensure that sewage from the structure does not cause a health hazard. This means, in part, that owners are required to follow the maintenance plan, and use Authorized Persons (ROWPs) to perform design, installation, repair and maintenance.  Owners are responsible to ensure the system is operated within the capabilities and limitations of that system.

Authorized Persons

The Sewerage System Regulation (SSR) defines two types of ‘Authorized Person’: a Registered Onsite Wastewater Practitioner (ROWP) and a Professional (typically a Professional Engineer). No others may plan, install or maintain systems in British Columbia. Doing so is illegal and considered an offense under the Regulation. An exception is allowed under the SSR for owners to construct their own systems, but only under the supervision of an Authorized Person and only with sewerage Filing and Certification documents prepared and submitted to Health Authorities by an Authorized Person.

Registered Onsite Wastewater Practitioner

Depending on training and qualifications, a Registered Onsite Wastewater Practitioner (ROWP) plans, installs, maintains and/or inspects onsite systems. They are registered with the Applied Science Technologists & Technicians of British Columbia (ASTTBC). To be registered, individuals must demonstrate specific competencies, achieve experience under the oversight of an Authorized Person, submit work example documents for review, provide references, successfully complete examinations, and undergo a Practice Assessment Review within six months of certification.

ROWPs must adhere to a strict Code of Ethics and also follow the Ministry of Health Services’ Sewage System Standard Practice Manual  which sets out best practices.

ASTTBC has four classifications of ROWP certification:

    • ROWP Planner – performs site and soil assessment, designs the system, certifies the system construction based on oversight of construction, and creates the extensive documentation required by the Regulation.
    • ROWP Installer – installs or repairs the system as designed and specified by a ROWP Planner.
    • ROWP Maintenance Provider – monitors and maintains the system according to the maintenance plan.
  • ROWP Private Inspector – inspects and provides conclusions about the performance, condition and capacity of existing systems.

ROWPs can be registered in more than one category. For example, the same ROWP may be certified to plan and install a system.


A Professional may design, install, and maintain all types of onsite systems. Only Professionals can certify construction of systems with Daily Design Flow greater than 9,100 L or systems using type 3 treatment.

ROWPs often engage Professionals when soil conditions are unfavourable or other significant constraints exist. One example occurs when systems can not be located at least 30 m from wells, in which case, written advice from a Professional must be submitted to the Health Authority. A ROWP may refer the entire project to a Professional or engage a Professional to provide the required oversight of the ROWP’s work.

Often Professionals will use the services of a ROWP and supervise them in the installation and maintenance of complex systems.

Professional Engineers (PEng) and Professional Geologists (PGeo) are registered with the Engineers & Geoscientists BC (EGBC)

Pre Treatment Systems

The regulation describes three different types of systems. In this context, “type” refers only to the pre treatment components of a system. Pre treatment is distinct from soil dispersal. Treatment system types are defined as follows:

  • Type 1 System
    Treatment by septic tank only. Conventional septic tanks provide settling and retention of solids in the tank. Some bacteriological breakdown of organic matter occurs, but treatment is ‘less than’ type 2 or 3 methods.
  • Type 2 System
    Type 2 treatment includes manufactured hardware, typically an additional tank with aeration and/or treatment media that encourages bacteria growth. Type 2 is defined as a method that consistently produces effluent with less than 45 mg/l of total suspended solids and less than 45 mg/l of biological oxygen demand.
  • Type 3 System
    Type 3 treatment also includes a manufactured treatment plant or similar hardware. More robust treatment is typically provided by disinfection processes. Type 3 is defined as a method that consistently produces effluent with less than 10 mg/l of total suspended solids, less than 10 mg/l of biological oxygen demand and a median fecal coliform (fecal bacteria) density of less than 400 colony forming units per 100 ml.

Simply put, a Type 1 system is the least complex and is used when site and soil conditions are favourable. Type 2 and Type 3 systems have additional complexity and cost, but can be used to ensure regulatory compliance and effective performance on challenging sites. When sites have shallow depth of suitable soil or limited area available for soil dispersal, using Type 2 or Type 3 treatment may be required.

Dispersal Systems

After pre treatment by type 1, 2 or 3 methods, effluent is discharged to soil using several different methods of soil dispersal, including (but not limited to) the following:

  • Gravity dispersal. Pre treated effluent (type 1, 2 or 3) is dispersed to soil using a non-uniform method. Typically, this includes a simple distribution box that splits effluent flow to several sections of perforated piping, either in trenches or a rectangular seepage bed. This is the simplest dispersal system. Advantages include low cost, simple maintenance and reliable performance. The primary disadvantage is that effluent is not evenly distributed to the entire soil surface of the dispersal trenches or bed. Therefore, they are not suited for many sites including those with shallow depth of suitable soil, or challenging soil conditions such as highly permeable sands or low permeability silts and clays.
  • Pressure dispersal. Pre treated effluent is dispersed to soil under low pressure using pumps (or other dosing technologies). Discharge piping is  drilled with many small orifices to produce ‘squirt’ discharge over the entire area of the trenches or bed. Advantages include consistent distribution (uniform dispersal) to the entire area of the drain field, making them suitable for shallower soils and more challenging soil types. Most sites in BC require uniform dispersal methods such as conventional pressure dispersal. Disadvantages include requirements for electrical service associated with the pumps and control systems. They are typically more expensive than simple gravity dispersal systems.
  • Subsurface drip dispersal. Pre treated effluent is dispersed to soil using pumps and controls, with drip line dispersal tubing. Advantages include very effective, even distribution of effluent to soil. They are ideal for shallower soils and difficult soil conditions. Disadvantages include higher cost (compared to gravity systems) and more frequent maintenance requirements.
  • The elevation of soil dispersal systems is dictated by the depth of suitable soil on the site. Standards require a minimum depth of naturally occurring, unsaturated and permeable soil, above limiting conditions such as the seasonal high water table, or restrictive layers such as clays or bedrock. Different dispersal methods (e.g. gravity, pressure, drip) require specific depths of suitable soil under the bottom of dispersal trenches, beds, or drip emitters. The required minimum depth of underlying soil (vertical separation) may be from 60 cm to over 150 cm. Accordingly, when the depth of naturally occurring soil is significant, trenches or beds may be placed at approximately 50 cm maximum depth. When depth of suitable soil is less, the elevation of trenches or beds, beds or drip emitters must be shallower in the soil profile, with cover soil added above original grade. When soils are very shallow (e.g. generally 60 cm or less) dispersal systems are placed at grade or raised above grade on specified sand media. Sand mounds are an example of a raised dispersal system. All at grade or raised systems require uniform dispersal methods.

Role of the Health Authorities

Health Authorities still play a role in onsite systems. They hold records related to sewage systems and are responsible to enforce the Regulation to protect public health. However, they do not approve or inspect new installations.

Role of ASTTBC

We are the Applied Science Technologists & Technicians of BC. Our role within the Regulatory framework is to register and govern the practice of Registered Onsite Wastewater Practitioners who perform regulated activities as Authorized Persons. For more information about those functions, please refer to How to Register  and Making a Complaint.

Improved Environment & Health Protection

Over the last 20 years there has been an increasing realisation that many onsite systems were designed to dispose of sewage, rather than to treat and disperse it. Although a system may have functioned without evidence of sewage coming to the surface, it was possible that effluent may have been contaminating the environment through the groundwater.

As development increases and more homes are built in rural subdivisions, environmental impacts and the potential for contamination of drinking water increases. With this comes a demand from the public for safe systems, as well as recognition by local governments that onsite systems are an integral part of a long-term waste management strategy. Modern systems are designed to treat the effluent adequately, disperse it with little or no impact to the environment or risk to health, and have a long, effective life.

Improved Systems

Because systems must now be designed to match site conditions and use, the SSR encourages the design and installation of quality onsite systems.

As the new approach encourages higher quality to ensure long life-spans, and as private contractors are taking responsibility previously taken by government, some systems are now more expensive than in the past. In other cases, the increased flexibility under the SSR leads to reduced costs. A quality onsite system is now seen as a real estate asset.

Improved Consumer Protection

In the past, untrained contractors or homeowners planned and installed systems in accordance with the regulation provided by the provincial Ministry of Health. This was done with the understanding that Health Officers would approve the plan, inspect the installation at various stages, and sign a final approval allowing for the operation of the system. Due to limited options available under the previous regulations, the onsite system component and location choices available to the consumer were limited as well.

Today, we have a regulation designed to be used consistently around the province by ROWPs who have considerably more training than offered by any other program in Canada.

ROWPs are:

ASTTBC is committed to ensuring protection of the public interest. This includes promoting professionalism of our members, ensuring that Registered Onsite Wastewater Practitioners have appropriate competency, meet all practice requirements, and act with integrity. If you have concerns or wish to make a complaint to ASTTBC about a ROWP, please refer to the section on Making a Complaint.