Your Yard: Landscaping, Vehicles and the Drain Field
The disposal field is a working part of your house. Treating it as ordinary lawn is how it gets destroyed.
20 questions in this section
- What can I plant over my drain field?
- Why not trees or shrubs?
- Can I put a vegetable garden over the field?
- Can I put down landscape fabric, plastic or a patio over it?
- Can I build a shed over my drain field or tank?
- Can I drive or park on my drain field?
- What about a basketball hoop or trampoline?
- Can I add fill or regrade over my field?
- Can I water my lawn over the drain field?
- Should I fertilize the grass over my field?
- Can I put a fence around or across my field?
- How do I mark my field so nobody drives on it?
- Can I use my drain field mound as a sledding hill?
- Does mowing hurt the field?
- What is the apron and taper, and can I landscape it?
- Can I put a driveway near my system?
- Will my field's location change if I renovate?
- Are there any plants that are actually good over a field?
- Can I keep livestock or a paddock over the field?
- How do I protect my system during construction on my property?
What can I plant over my drain field?
Grass, and essentially only grass. Shallow-rooted turf protects the surface, prevents erosion and helps move moisture out of the soil through evapotranspiration.
Why not trees or shrubs?
Roots from nearby trees and shrubs seek out the water and nutrients in your field and can clog and damage distribution lines. Repairing root intrusion means excavating the field, which requires an approval.
Can I put a vegetable garden over the field?
No. Effluent in the soil can carry pathogens, and root vegetables and low-growing produce can be contaminated. Keep food gardens well away from the field.
Can I put down landscape fabric, plastic or a patio over it?
No. The soil over a field needs to breathe. New Brunswick's Guidelines cap cover thickness precisely because the treatment process is aerobic. Plastic sheeting, pavers, patios and gravel pads all smother it.
Can I build a shed over my drain field or tank?
No. Nothing that limits access should be built over a tank or pump chamber, and structures over the field block air exchange and prevent maintenance access.
Can I drive or park on my drain field?
No. Vehicle weight compacts the soil, which destroys its ability to accept and treat effluent, and can crush pipes and chambers. This includes trailers, campers and equipment.
What about a basketball hoop or trampoline?
Light, movable items are less of a concern than compaction from repeated traffic, but anything that concentrates foot traffic or requires anchoring into the field should go elsewhere.
Can I add fill or regrade over my field?
Not without advice. Adding soil beyond the specified cover thickness suffocates the field, and regrading can redirect surface water onto it. Cover should not exceed 60 cm unless alternative aeration is provided.
Can I water my lawn over the drain field?
Go easy. Irrigation adds water the field then has to handle on top of household flow. Established grass over a field generally needs less watering than the rest of the lawn anyway.
Should I fertilize the grass over my field?
Rarely necessary - the field already supplies nutrients. That is why the grass is often greener there.
Can I put a fence around or across my field?
Fence posts driven into a field can damage pipes and chambers. If you need a fence, have the system located first and keep posts outside the field limits, apron and taper.
How do I mark my field so nobody drives on it?
Discreet markers at the corners, a change in landscaping at the edges, or simply a plan of the system posted in the garage. Marking matters most before snow covers everything.
Can I use my drain field mound as a sledding hill?
No. Repeated traffic compacts the soil and snow, and the mound's taper is doing structural work. Keep it clear.
Does mowing hurt the field?
Ordinary mowing with a walk-behind or light ride-on is fine. Heavy ride-on mowers and tractors on saturated ground can compact it, so avoid mowing the field when the ground is soft.
What is the apron and taper, and can I landscape it?
On a mound system, the apron is the sand buffer extending 6 metres downslope and 3 metres on other sides, and the taper is the 4:1 slope back to grade. Both are part of the system. Grass only, no excavation, no structures.
Can I put a driveway near my system?
Keep it outside the field limits including apron and taper, and outside the tank access area, and make sure runoff from it is directed away from the field.
Will my field's location change if I renovate?
The system stays where it is. Renovations that add bedrooms or fixtures may require a larger system, and additions must respect the setbacks - 3 metres from the field, 1.5 metres from the tank.
Are there any plants that are actually good over a field?
Native grasses and shallow-rooted meadow species work well. The goal is dense, shallow root cover that holds soil, transpires moisture and does not chase pipes.
Can I keep livestock or a paddock over the field?
No. Hoof traffic compacts soil severely, and manure adds nutrient loading. Fence animals well away from the system.
How do I protect my system during construction on my property?
Locate and flag the tank, field, apron and taper before any equipment arrives, and route all machine traffic and material storage away from them. Compaction from a single loaded truck can do lasting damage.
Have a question about your own property? General answers only go so far — your soil, slope, water table and setbacks are specific to your lot. Call (506) 233-6272 or send us the details.
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