Future Plans

The Englishman River Water Service is planning to expand the joint venture drinking water supply system with a new surface water intake and water treatment plant along the Englishman River and water main upgrades and installation of new water supply lines.

This is required to ensure that an adequate volume of bulk water can be provided, and that the water meets today's standards for good quality drinking water. There are many factors contributing to the need to expand the water supply infrastructure which include greater reliability and security, higher drinking water quality standards, and increasing water demands.

The intake and water treatment plant will be constructed at a site near the Highway 19 Bridge and railway crossing, on the east side of the Englishman River. The intake will be located at a bend along the river, slightly upstream of the highway crossing. The water treatment plant site (8.7 hectares) is an abandoned gravel pit behind the City of Parksville public works yard. A 600 millimetre diameter raw watermain will connect the intake to the treatment plant.

The three AWS joint venture participants require bulk water at different times. Based on current information, the City of Parksville and the RDN Nanoose area will require additional water supplies by 2015/16. The Town of Qualicum Beach will not require bulk water in the near future. Water conservation and water use reduction may serve to extend these time frames.

Securing Supply Capacity

There is general concern of declining groundwater levels in the region's aquifers, due to increasing demands on the aquifers and on climatic changes. Longer, drier summers, less precipitation and shorter periods of rain reduce the amount of recharge available to the aquifer. It is prudent to secure additional water sources in case groundwater levels continue to decline and well yields begin to suffer. Having multiple supply sources available also provides contingency should the use of one source be temporarily suspended. It also reduces stresses on a single source thereby supporting recovery and more sustainable supplies.

The AWS partners promote water conservation through metering, pricing and public education. In all AWS communities, water utility billing is structured to encourage conservation, help the environment and make financial sense. Water conservation is one means of deferring the demand for bulk water and the associated tax increases that will be necessary to pay for new infrastructure.

Water conservation and water use reduction will help meet water supply demands for drinking, fire protection and irrigation. Water conservation also ensures sufficient water is retained for habitat maintenance and protection.

Arrowsmith Water Treatment Plant

To comply with recent Vancouver Island Health Authority water quality objectives, additional treatment of the Englishman River water is required by the end of 2016. The primary treatment objectives are to reduce turbidity and reduce the risk of microbial contamination. The treatment facility can be expanded in phases to accommodate the region's water demands over time.

Vancouver Island Health Authority Operating Permit

Englishman River Intake

The most suitable intake design depends upon the nature of the river at a given site. Generally speaking, the majority of the river that is being considered for the intake is best served by a riverbank intake. The concept of a riverbank intake is simple; water enters the intake structure and flows through concrete channels to a chamber called a wet well. From the wet well the water is pumped to the treatment plant. The concrete channels contain progressively finer screens that prevent debris and large materials from entering the intake, and block fish from entering the wet well. Bypass channels encourage fish that have entered the intake towards a fish wet well. Fish that reach this well enter a fish-friendly return that leads fish out of the intake and back to the river without causing injury.

Riverbank filtration wells were reviewed several times over the last twenty years by qualified hydrologists and engineers in both the existing and proposed intake locations. It was found that the local geology did not support adequate water extraction and more water could be obtained by constructing a conventional river side intake structure.

Other factors limiting riverbank filtration are:

Health requirements would still require water treatment.
Subject to flooding and erosion with possible loss of well head due to the alluvial section of the river.
Direct takes are less problematic to operate and maintain.

Aquifer Storage and Recovery

Aquifer Storage and Recover (ASR) is defined as the storage of water in a suitable aquifer when water is available and recovery of the same water later on when it is needed. A typical schematic of an ASR well, used to both inject and withdraw water, is shown in the illustration below. Although the concept is simple, ASR has only been implemented relatively recently by the water industry. There are approximately 100 ASR systems in production or in the planning stages in the United States and one operating in Canada in the Kitchener - Waterloo area.

Incorporating ASR into the system would involve contributing water to the storage aquifer in the winter, when excess supply is available and withdrawing this water in the summer when supply is most challenged to meet demands. ASR would create an additional supply for the Englishman River Water Service, which would provide more contingency should one supply source be taken offline, and allow the ERWS greater flexibility in managing the water resources. ASR can reduce the maximum amount of water that needs to be supplied by the treatment plant. This means that less water will need to be drawn from the Englishman River during the summer, when river water levels are at their yearly low.

In order to determine if ASR is feasible, further investigation is required.

ASR requires an aquifer with specific characteristics such that the aquifer can protect and contain the stored water, but also allow easy extraction. Of the 13 aquifer systems in the region, 5 of them were identified as potentially suitable candidates.

The most suitable locations appear to be between Parksville and Nanoose. The map below shows the potential areas.

Preferred Candidate Areas for ASR

There are some general uncertainties when considering ASR. One risk is that the storage aquifer may not be sufficiently confined to fully retain the stored water. Some losses are expected as water slowly migrates through the ground, but if the losses are significant the amount of stored water that can be recovered might be unacceptably low. A second risk is that water injected into the aquifer may pick up material that is in the ground, such as iron and manganese. This may lead to the stored water requiring additional treatment when the water is pulled back out of the aquifer. To assess these risks for the AWS region, an extensive testing feasibility program is required to more accurately characterize the candidate sites and to simulate the ASR process. The testing program is planned to begin in 2012.

ASR Benefits:

Provides a "third water supply".
Could potentially reduce the Englishman River water extraction up to 50% in the critical summer months.
Allows balanced water supply.
Provides cooler water during summer consumption.
Can be substantially lower cost than above ground storage reservoirs.