Groundwater Protection

The Sardis-Vedder Aquifer

Clean groundwater is a vital resource, fundamental to our everyday activities, health, economic well being and ultimately our survival. In the City of Chilliwack, water is obtained from the Sardis-Vedder Aquifer, a natural underground water reservoir.

Due to the permeable nature of the soils overlaying the aquifer, contaminant migration into this groundwater resource is a concern. You can assist the community by taking measures to prevent chemical and waste spills by ensuring that all hazardous materials are transported, stored, and disposed of correctly, and by working with other members of the community to minimize activities that pose a risk to the quality of our groundwater resources. 

Where is the Sardis-Vedder Aquifer?

The Sardis-Vedder Aquifer lies immediately north of the Vedder River in Sardis and extends north to the No. 1 Highway. It is bounded on the west by the City’s border with Abbotsford and on the east by Prest Road. The location of the aquifer is shown in the adjacent figure. The vulnerability of the areas is indicated by colour coding, red being the most vulnerable area followed by pink then green. (ref: Evaluating Methods of Aquifer Vulnerability Mapping for the Prevention of Groundwater Contamination in BC by K. Ronneseth, M.Wei and M. Gallow of MOE, Dec 1995)

How could the Sardis-Vedder Aquifer become contaminated?

Aquifers are composed of permeable layers of rock, sand, or gravel that enable surface waters, including streams, rivers and precipitation, to percolate into the ground and recharge groundwater resources.

The Sardis-Vedder Aquifer is particularly vulnerable to contamination for several reasons. First, the upper layer of groundwater, the water table, lies only a shallow five to ten meters below the ground’s surface. This is significant, as chemicals or waste materials must travel only a short distance through the soil to impact groundwater quality. Second, the boundary layer of soil protecting groundwater from the upper surface is coarse-grained and consequently extremely permeable. Rainfall quickly seeps through the pores of the coarse soil, carrying contaminants from the surface to the aquifer below. As Chilliwack receives high rainfall, particularly during winter months, preventing the ingress of contaminants due to surface spills is essential.  

It should be noted that the City’s wells pump water from a much deeper zone and water is pumped from a depth of 30 to 40 metres below the ground where the volume and quality of the groundwater is very high.

Materials That Can Impact Groundwater Quality

The following list provides several examples of common materials that can negatively impact groundwater quality:

Acids Fertilizers Lubrication oils Salts
Antifreeze Gasoline Manure Sewage
Brake fluid Grease Motor oils Shellacs
Cleaners Hazardous wastes* Paints Solvents


Paint Strippers Thinners


Pesticides Varnish
Dry Cleaning Agents                 Lacquers Poisons  

*Note: Hazardous materials are any products that are ignitable, toxic, corrosive or explosive.

A Resident’s Guide

Residents can help protect our valuable groundwater by following the guidelines listed in this section.

Fertilizer Use | Household Hazardous Wastes | Protect Our Drinking Water | Protect our Storm Drains | Contact Information

Drinking Water Quality Information

In Chilliwack, we have good reason to be proud of our drinking water.

Groundwater Protection Plan

Chilliwack has great groundwater, let's all help to keep it that way!This document outlines the characteristics of our aquifers, our current and future use of them, as well as the potential threats they face.

Local Businesses

Groundwater Protection for Local Businesses

Pesticide Users

Groundwater Protection for Pesticide Users

Private Well Owners

Groundwater Protection for Private Well Owners

Septic System Users

Groundwater Protection for Septic System Users

Storm Drain Marking

The water that enters storm drains is not treated before release to the environment! Visit the site for information about storm drains in Chilliwack and the Storm Drain Marking Program.