Water Service Plans
The ERWS will expand the joint venture drinking water supply system to provide a new surface water intake and water treatment plant along the Englishman River and as well as water main upgrades and the installation of new water distribution mains.
This project is required to ensure an adequate volume of bulk water and to meet Island Health's drinking water standards for good quality drinking water. There are many factors contributing to the need to expand the water supply infrastructure such as 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 will be located on a site behind the City of Parksville operations yard. The reduced sized treatment plant which takes into financial constraints, will have a minimum of 16 million litres per day of firm membrane filtration capacity.
Planning for your water
There is general concern of declining groundwater levels in this region's aquifers due to increasing demands on the aquifers and on changes to our climate. 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 the event that groundwater levels continue to decline and well yields begin to suffer.
The City of Parksville and the Regional District of Nanaimo promote water conservation through metering, pricing and public education and water utility billing is structured to encourage conservation. Water conservation and water use reduction helps to meet water supply demands for drinking, fire protection and irrigation. Water conservation also ensures sufficient water is retained for habitat maintenance and protection.
ERWS - Water Treatment
To comply with Island Health (formerly Vancouver Island Health Authority) water quality objectives, additional treatment of Englishman River water is required. The new treatment plant is necessary to reduce the risk of contamination therefore ensuring an adequate supply which meets Canadian Drinking Water Guidelines and Island Health's disinfection requirements. Treatment objectives include reduced turbidity and the risk of microbial contamination. The treatment facility will be expanded in phases to accommodate the region's water demands over time.
ERWS partners are moving forward with the planned expansion to the drinking water supply which includes the detailed design of the treatment plant with a minimum of 16 million litres per day of firm membrane filtration capacity.
There are naturally occurring microbiological pathogens such as E. coli present in our surface water which has typically been removed using chlorine disinfection. There are also organisms such as Cryptosporidium and Giardia which are not removed with the use of chlorine. The most effective means to ensure such organisms do not find their way into the community's potable water supply is by using the multi-barrier approach which is required by Island Health to meet their health standards and to be in compliance with Canadian Drinking Water Guidelines. The multi-barrier approach, filtration, ultraviolet light and chlorination, works to ensure safe healthy water is delivered to residents.
If water from the Englishman River was relatively free of the silts and sediment (turbidity), treating the water would only require simple direct filtration, disinfection by means of ultraviolet light followed by chlorine disinfection. This is not the case with the Englishman River water source as turbidly events happen on a regular basis through the fall, winter and spring and occasionally during summer months. With turbidity a problem throughout the year, any treatment system must be able to achieve turbidity and microbiological removal at the same time.
Several options have been investigated to remove turbidly and settle it out prior to treatment including constructing raw water reservoirs ahead of the water treatment plant. A few days of raw water storage may reduce turbidly spikes entering the treatment facility during the events therefore allowing a low-turbidity tolerant process such as direct filtration, ultraviolet light disinfection.
Water treatment options
A number of water treatment technology processes were reviewed and considered suitable for treating the Englishman River water source, these were:
- Direct filtration
- Conventional treatment (sedimentation/media filtration)
- Dissolved air flotation/media filtration (DAF)
- Membrane filtration
- Ballasted flocculation (ActifloŽ/media filtration)
Two technologies were selected for small scale water treatment piloting; conventional treatment and pressurized membrane treatment. The piloting project started in fall 2011 and finished in spring 2012 and used water from the Englishman River to flow through the small scale water treatment plants to test the treatment processes under the challenging conditions. The purpose of doing small scale water treatment plant piloting was to prove such technologies and ensure treatment objectives are met prior to building the full scale water treatment plant. During this period, the pilot water treatment plants experienced typical high turbidity events in the fall resulting from the first initial winter storms and early spring freshet flows. Pilot testing determined membrane technology water treatment best suits the Englishman River water source.
ERWS - River Intake
A new surface water intake will be installed in the Englishman River. This intake will carefully consider the needs of river users and fisheries.
The location of a new water intake site is a major piece of the water supply puzzle. The location is of interest to many in our community and First Nations have a traditional link to the river. From a health perspective, a location further up the watershed is seen as beneficial while an intake as far down the river as possible can be viewed as the most beneficial approach for fisheries. When engineering and cost considerations are taken into consideration, the choice for the location of an intake becomes complex.
Early plans for an intake on the Englishman River developed several options based on gravity systems above the Englishman River Falls which would deliver water to the community through a reservoir located on Little Mountain. Options were discussed with fisheries agencies who determined a lower intake would have less impact on fish. The lower intake location would also allow for additional fisheries enhancements such as the construction of the side channel spawning hatchery located on the west side of the Englishman River at the confluence of the South Englishman River.
In 1997, a conditional water licence was issued authorizing the construction of the Arrowsmith Dam and storage of 9 million cubic meters. Half the volume was to be reserved for fisheries enhancements with the remaining storage for the community's drinking water.
Between 2000 and 2005, engineering studies were commissioned focusing on the future water intake location. This work took into account a sustainable approach weighing environmental, financial and social factors with the best location downstream of the originally proposed intake at the confluence of the South Englishman River. Meetings were held with health authorities, DFO and provincial fisheries and regulators to discuss this option. In 2011, Associated Engineering (BC) Ltd. finalized the report and concluded the best location for the downstream intake location is just above the Highway 19 Bridge. The report also concluded both future water supply and fisheries flow requirements can be achieved by the release of additional flows from the Arrowsmith Dam during critical summer months.
In January 2012, a change of works application was approved by the province to locate the water intake just above Highway 19 on the right bank in Top Bridge Park owned by the City of Parksville. The proposed intake is a river side inlet structure.
Many different technologies and structures were reviewed to best determine the most suitable for operating, ease of withdrawal and environmental impact. These intake structures were reviewed:
- River side inlet (chosen inlet type)
- Obermeyer weir
- Coanda screens
- Riverbank filtration wells
- Submerged intake
- River bottom infiltration gallery
- River side intake pond
- River side infiltration gallery