Learn how to protect Surrey's water system by following these single-family home best practices.

In our homes, there are many ways cross connections can happen. The following are common hazards that can cause serious backflow into the City's water system and what you can do to prevent it.

Common household hazards

Submerged hoses

Water held in pools, ponds or other vats open to air and exposed to humans or animals may contain contaminants. Hoses submerged in buckets or containers can act as a conduit for contaminants under backflow conditions.

What to do: Install hose connection vacuum breakers (HCVB) on the facet of your water hose. These are inexpensive and can be found at local plumbing and hardware stores.

Chemical spray applicators

The chemicals used on your lawn and garden can be toxic or fatal if ingested. These chemicals may include pesticides, herbicides, fertilizers, and even the strong cleaning chemicals sprayed on vehicles, house siding, etc.

What to: Hire a certified plumber to select and install the proper backflow preventer device.

Underground lawn irrigation systems

Sprinkler heads are not designed to be drip tight under backflow conditions. Because of this, fertilizer, animal excrement, and other contaminants in puddles of standing water are at risk of back flow through ground level sprinkler heads.

What to do: Ensure an approved backflow device is installed, in good working order and is tested annually if it requires testing.

Residential boilers and geo-thermal systems

Ensure there is an approved backflow assembly on the connection between the main water supply and makeup to the two systems.

Private wells and auxiliary water systems

Ensure well systems are not interconnected to the public water distribution systems.


Ensure your backflow preventers are working properly. Hire a plumbing contractor when in doubt. Some devices require testing annually, small amounts of matter are capable of plugging up the devices and causing them to malfunction, these problems can be avoided with a well scheduled maintenance program.