Water Quality
Onsite
Sewage Systems
Onsite
Sewage Systems > Solutions >
References and Links
Onsite
Sewage Systems
Onsite sewage
systems are effective at treating household sewage if designed
and installed properly in appropriate soil and maintained regularly.
In typical onsite sewage systems, the wastewater from toilets
and other drains flows from your house into a tank that separates
the solids and scum from the liquid. Bacteria help break down
the solids into sludge. The liquid flows out of the tank into
a network of pipes buried in a disposal field of gravel and soil.
Holes in the pipes allow the wastewater to be released into the
disposal field. The soil, gravel and naturally occurring bacteria
in the soil filter and cleanse the wastewater. There are about
250,000 onsite sewage systems in British Columbia, despite expansion
of municipal sewage collection and treatment facilities.
Typical
onsite sewage system (adapted from the Soap
and Detergent Association)
Onsite systems that are poorly planned, constructed or maintained
present substantial threats to water quality in the province.
Onsite sewage systems can fail and untreated wastewater can be
carried to nearby waterbodies threatening human health, causing
excessive algal growth and harming aquatic life. If your onsite
system is not properly located on your property or does not have
an appropriate depth of suitable soil, the system may not fully
treat the wastewater. The wastewater can seep down into the ground water
polluting drinking water supplies or rise to the surface and flow
over land into nearby waterbodies. If you don't have your septic
tank pumped out regularly, the solids and scum can flow into the
drainfield and plug it up. If the drainfield gets clogged, untreated
wastewater can rise to the surface threatening your family's and
neighbors' health, reducing the value of your property and creating
odours and the need for costly repairs. Heavy use of strong disinfectants
can kill the beneficial bacteria in the soil around your disposal
field and reduce the natural cleansing function of your system.
Finally, if you use too much water in your home, wastewater can
be flushed out too quickly and solids can flow into the drainfield,
causing it to plug. The less you flush or pour down your drains,
the better your system will work.
You may have
a failing onsite sewage system if you notice one or more of the
following signs:
- unusually
green or spongy grass over the system;
- toilets,
showers and sinks back up or take a long time to drain;
- sewage
surfacing on your lawn or in a nearby ditch;
- sewage
odours around your yard, especially after rain.
Alternative
sewage disposal systems are available to replace conventional
onsite systems. These systems can stand alone or be used in combination
with conventional systems. They not only can reduce the impact
of the conventional onsite sewage disposal systems on water quality,
but can reduce the amount of waste produced. Alternative sewage
disposal systems can produce high quality effluent and conserve
water through low usage.
Solutions
The following
tips will help you prevent NPS pollution from your onsite sewage
system:
- You must
obtain a permit from the local Health Authority before installing,
repairing or upgrading an onsite sewage system. This will ensure
that your system meets local requirements for density, setbacks,
size, location and construction.
- Take the
time to be aware of your system — owners have to play
a role in the management and maintenance of their system. Create
a map of your lot showing the location of the onsite sewage
system and leave it for the next owners.
- Have your
system inspected yearly and pumped out every 2 to 5 years by
a qualified septic service company. Regular pumping and routine
maintenance of all system components is cheaper than having
to rebuild a drainfield.
- Upgrade
your onsite sewage system when you upgrade your home (i.e.,
when you add a bedroom or a suite).
- Practice
water conservation — use water wisely. For example, run
the dishwasher only when full and use low-flow showerheads and
toilets.
- Don't
use garburators — this will reduce the amount of solids
and grease you put into the system.
- Don't
put toxic chemicals down the drain because they can kill the
bacteria at work in your onsite sewage system and can contaminate
waterbodies.
- Avoid
pouring grease or fats down the drain.
- Use biodegradable
household cleaners instead of bleach or other hazardous products.
- Avoid
flushing pet wastes into the system — bury them away from
the drainfield instead.
- Don't
drive, pave or put heavy objects or machinery over the drainfield.
- Avoid
planting trees or shrubs near the drainfield because their roots
can damage or plug the pipes.
- Don't
over-water the drainfield or allow roof or perimeter drains
to run onto the drainfield.
- Don't
use septic 'starters' or similar products; they are unnecessary,
expensive and may cause pollution.
Regular inspection and maintenance will maximize
the life and performance of your system
References
and Links
Public
Health Protection Septic System Program. Ministry of Health
Planning.
The
National Small Flows Clearinghouse. United States Environmental
Protection Agency.
Principles
and Design of On-Site Waste Disposal with Septic Systems.
United States Environmental Protection Agency.
The
Septic Information Website.
The
Septic Education Kit.
Septic
System Maintenance — Pure & Simple. Environmental
Health Foundation of Canada. Brochure and Video.
Tackling
Non-Point Source Water Pollution in British Columbia: An Action
Plan. 1999. Ministry of Environment, Lands and Parks.
