Sewer Lateral Cross-Connections

Many homes in Hamilton have two types of sewer pipes. They are known as sanitary and stormwater pipes. Both pipes serve a different purpose.

Your home’s sanitary pipes take water from your toilets, sinks, showers, laundry, and other home drains and send it to the wastewater treatment plant. Once treated, the water is released back into the natural environment.

Your home’s stormwater pipe collects rainwater and snowmelt from roofs, downspouts, foundation drains (weeping tiles) or private catch basins and sends it to the City storm sewer main. From there, the water travels without further treatment to nearby stormwater management ponds,  natural watercourses, Hamilton Harbour, or Lake Ontario.

Sanitary sewer systems and stormwater sewer systems should exist entirely separate from one another.

Separated sewer system

In a separated sewer system, the home’s sanitary pipes lead directly to the sanitary sewer main and the stormwater pipes all lead to the stormwater sewer main. These two systems are kept completely separate as intended. Treatment of stormwater can differ greatly from that of sanitary wastewater, which is why it is important to keep these two systems separate.

Complete Cross-connections

A complete cross-connection happens when a home’s sanitary pipe is mistakenly tied into the storm sewer main and the stormwater pipe is mistakenly connected to the sanitary sewer main. This usually happens at the time of the home’s initial construction.

Partial Cross-connections

A partial cross-connection happens when some of a home’s internal plumbing is mistakenly tied into the stormwater pipe that leads to the storm sewer main. This usually happens during renovations or additions and most commonly when a bathroom is added to a basement.

Indirect Cross-connections

An indirect cross-connection occurs when a home’s sanitary and storm pipe are properly connected to the sewer mains, but are damaged or in poor repair. This can allow wastewater to leak out from the sanitary pipe and seep into the storm pipe. This usually happens with old pipes that are not maintained.

Implications of a Cross-connections

Cross-connections can:

• Allow harmful waste to enter the stormwater channels which end up polluting local creeks and natural watercourses.
• Overburden the sanitary sewer system and wastewater treatment plant with stormwater
• Result in expensive repairs in order to correct the complete or partial cross-connection

What the City is doing about it

The City created the Sewer Lateral Cross-Connection program in 2002 to identify and correct cross-connections within Hamilton. The program inspects over 45km of mainline sewer pipes each year to find existing cross-connections. Once found, the City digs up the pipes and they are properly connected. The City has fixed more than 450 cross-connections to date, resulting in over 100 million litres annually of wastewater going back into the collection system rather than out into watercourses.

What you can do to prevent cross-connections

You can help prevent partial cross-connections. When planning renovations or additions in your home, ensure that you have the proper permits. Whether you are hiring a professional contractor or doing the work yourself, it is extremely important that you have the proper permits and complete the required inspections. This will ensure that the work has been done correctly, prevent costly repairs in the future, and protect the environment.