Septic systems, wells and lake water

Most Ontario cottages are not on town sewers or town water. The property treats its own waste and supplies its own water. These systems are out of sight, costly to replace and easy to check before you buy. This guide explains how they work and what to ask for.

How a septic system works

A standard system has two parts. Waste water flows from the cottage into a buried septic tank. Solids settle to the bottom, grease floats to the top, and bacteria break some of it down. The liquid in the middle flows out to the leaching bed, a set of perforated pipes in gravel or sand. The soil finishes the treatment as the water soaks down.

The tank has to be pumped out every few years, because the solids do not leave on their own. If they build up and wash into the bed, the bed clogs. A new bed is the expensive part of any septic repair.

Some lots have an advanced treatment unit in place of, or ahead of, a standard bed. These are common on small or rocky lots. They usually need a service contract with a licensed provider, so ask for it.

The rules: Ontario Building Code Part 8

Septic systems that serve a single property are regulated under Part 8 of the Ontario Building Code. You need a permit to install, replace or alter one. The Code also sets rules for operating and maintaining a system.

The office that issues permits and inspects systems is not the same everywhere. Depending on the area, it is the municipality, the local board of health or a conservation authority. In parts of eastern Ontario, for example, the Rideau Valley and Mississippi Valley conservation authorities run septic programs for local townships. Call the township office and ask who handles septic files for that address.

That office is also where you ask for the septic use permit or installation record. It shows the age, size and location of the system and how many bedrooms it was designed for. A cottage with five bedrooms and a permit for three is a problem for you, for a lender and for any rental licence.

Re-inspection programs

The Building Code requires maintenance inspections every five years in certain designated areas, including parts of the Lake Simcoe watershed. Outside those areas, a township can choose to run its own program, and a growing number of cottage-country townships do.

• The Township of Muskoka Lakes rates systems by risk and inspects them by zone. A first-phase check is a short visual visit. A second-phase inspection opens the tank and checks the bed.
• The Township of Rideau Lakes and Central Frontenac have mandatory programs. Tay Valley Township has a mandatory program on certain lakes and a voluntary one elsewhere.

Ask the seller for the latest re-inspection report and any orders to fix deficiencies.

Make septic an offer condition

A common condition is a satisfactory septic inspection with a pump-out. The tank is pumped so the inspector can see the walls, baffles and inlet and outlet pipes. The inspector also walks the bed and may run a flow test. Agree in the offer on who pays for the pump-out.

Signs of a failing bed include:

• Wet, spongy ground or standing water over the bed
• Sewage smell outside, or near the tank
• Very green, lush grass in strips over the pipes
• Slow drains or backups inside
• Trees, a driveway, a deck or a shed built over the bed

Holding tanks

A holding tank stores everything and treats nothing. A truck pumps it out and hauls the waste away. Ontario generally does not allow holding tanks for new development. They are accepted only in limited cases, such as an existing lot too small for any other system. If a cottage has one, budget for frequent pump-outs, check winter truck access and ask your lender early, since some lenders and mortgage insurers are cautious about them.

Drilled wells and dug wells

A drilled well is a narrow steel-cased hole, often quite deep, that reaches water in bedrock or deep gravel. It is usually the more reliable choice for quantity and quality. A dug or bored well is wide and shallow. It draws from water close to the surface, so it is more likely to run low in a dry summer and more exposed to surface contamination.

Ask for the well record, which gives the depth, the date drilled and the flow when it was built. Look at the well head. The casing should stand above the ground, the cap should be tight, and the ground should slope away from it.

Lake-drawn water

Many cottages pump water straight from the lake. Untreated lake water is not safe to drink. A typical treatment set-up has sediment filters followed by an ultraviolet (UV) light that kills bacteria. Filters and the UV lamp need regular replacement, so ask when that was last done.

Water tests and flow tests

Make the offer conditional on a water potability test. Public Health Ontario tests private drinking water for bacteria (E. coli and total coliforms) at no charge for Ontario residents. This covers wells, cisterns and treated lake water. You pick up a sample bottle from the local public health unit or another listed location, and results usually come back within a few business days.

That free test covers bacteria only. For minerals, metals or chemicals, such as sodium, nitrates, arsenic or uranium, use a licensed private lab.

A flow test checks quantity. A well contractor or inspector runs water for a set time and measures how fast the well recovers. Lenders sometimes ask for a minimum flow rate, so check your lender's number.

Heat lines for winter

A cottage used in winter needs a water line that will not freeze. A lake intake or shallow well line is usually protected with a heat line, an electric heating cable in or along the pipe, plus insulation. Ask if the line is heated all the way from the source to the building, and ask what happens in a power failure. If there is no heat line, the system has to be drained each fall. Our guide to seasonal vs four-season cottages has more.

Wood stoves and WETT inspections

Most insurers will ask about any wood stove, fireplace or pellet stove, and many want a WETT inspection before they will cover the cottage. WETT stands for Wood Energy Technology Transfer, a body that trains and certifies people. A WETT-certified inspector checks the appliance, chimney and clearances against the codes and writes a report. There is no such thing as a "WETT-certified" stove, since WETT certifies people, not equipment.

Make the offer conditional on a satisfactory WETT inspection and on getting insurance.

Checklist for your offer

1. Septic use permit and pump-out records from the seller
2. Septic inspection with pump-out
3. Well record, or details of the lake water system
4. Water potability test, plus a flow test for wells
5. WETT inspection for any wood-burning appliance
6. Confirmation of insurance

The full list of conditions is in the Ontario Cottage Buyers Guide.