Aquifer Storage and Recovery System

Salem is growing and with it the demand for water. The question is, how to find a second reliable water source without damaging the environment and creating huge costs to the rate payer. Salem is one of a growing number of cities in the United States going underground for the answer.

What is an Aquifer Storage and Recovery System?

The volcanic action of 17 million years ago has created just the right conditions for water storage beneath the South Salem Hills. The cavities between the jumble of rocks formed by the Columbia River Basalt Lava Flows hold water much like an irregular honey-comb contains honey. The Aquifer Storage and Recover (ASR) system uses the latest technology to pipe treated drinking water from the North Santiam River during winter into the aquifer where it is stored. When summer brings peak demands, or during an emergency, the water is recovered by pumping it back out of the aquifer.

Why use ASR?

An ASR system was identified in the City's Water System Master Plan as the preferred new secondary water source. There are a number of advantages to using ASR:

The system is a useful back-up during emergencies. (It was activated during the floods of February 1996).

More water can be left in the river during summer low flows. This means more water for fish and for people to enjoy water sports.

Water from this source is often colder in the summer than water which comes from surface supplies.

ASR can be added to the piping of the existing water supply system. There is no need to build expensive new infrastructure.

A covered storage area is less vulnerable to contamination than an open reservoir.

How will ASR affect me?

Salem residents will receive water from the aquifer during peak periods. Although the water source is 300 feet underground, it is always best to take care to ensure the continued high quality of this special water.

Salmon and trout populations need cool and plentiful water in the river. ASR is good news for them because it keeps more water in the river during summer.

Vital Statistics

Over the next 20 years, Salem's water service population is projected to grow from 150,000 to 230,000. Even with conservation, which is targeted to reduce peak demand by at least 10%, maximum water demand should soar to over 90 million gallons of water a day.

The North Santiam River will remain the City's primary water source, but the capacity to treat and deliver the water to Salem is going to be expanded. Aquifer Storage and Recovery will continue to play a vital role by allowing high river flows in the winter to be stored underground for use in the summer.