Nova Scotia resort utilizes on-site distributed wastewater disposal systems

As featured in Environmental Science & Engineering Magazine.

Forest Lakes Country Club is a four-season resort community under construction in Ardoise, just outside Halifax, Nova Scotia. The development will ultimately include 2,700 single-family, townhouse and multi-unit residential units, the only Nicklaus Design championship golf course in Atlantic Canada, and a village centre with commercial and retail operations. Several of the resort’s neighborhoods will be adjacent to the golf course.  The Forest Lakes village centre will be accessible from all areas of the resort and will include retail shops, cafes, hotels, restaurants, a family entertainment centre, and a spa and wellness centre for residents and non-residents. Additionally, three lakes, a boathouse, walking trails and a horse riding area will all appeal to those looking to live in a natural setting, with the traditional housing, services and amenities typical of a modern municipal community development.

The Ardoise area’s topography includes wetlands, rocky areas and a variety of soils, with no centralized municipal sewer or wastewater treatment infrastructure. In developing the Forest Lakes project, Terra Firma Development Corporation embraced a low impact strategy that would retain the rural nature of the area, while providing a wide range of housing units and recreational opportunities. The resort site development plans, including the wastewater collection, treatment and disposal approach, had to minimize environmental impact, while facilitating the growth of the development over time.

SUSTAINABLE BUILDING FOCUS
The homes at Forest Lakes incorporate the latest in sustainable building practices to reduce energy and water consumption. The developer is a member of the Canada Green Building Council.
Due to the overall size of the resort community and the wide range of developments at the site, traditional on-site wastewater treatment was not a viable option for most of the community. Minimum lot sizes for individual dispersal fields would have greatly impacted lot sizing and layout and reduced valuable and developable area that might otherwise be available for housing units, green spaces and resort facilities. Instead, the developer chose cluster-type configurations with large green spaces between and around homes and recreational areas. This enabled planned residential areas.

This enabled planned residential and recreational development, while also protecting environmentally sensitive areas. It simplified the provision of essential water, sewer and other utility services. Large open spaces in the clustered neighbourhood development also provided better opportunities for locating dispersal areas to minimize any possibility of adverse environmental impact. The Nicklaus Design golf course incorporates the wide-ranging topography of the area, including forests, lakes, ponds, rock outcroppings and natural wetlands. Its design aims to enhance the surrounding environment and minimize environmental impacts by incorporating sustainable landscaping principles to maximize the use of recycled or reclaimed water for irrigation.

The initial neighborhood system, serving 50 single family and semi-detached homes, is designed to treat a peak flow of 51,200 litres per day of residential sanitary wastewater.

WASTEWATER TREATMENT SYSTEM SPECIFICS
Each neighbourhood at Forest Lakes utilizes a decentralized wastewater collection, treatment and disposal system. A key design consideration for these systems was that they work reliably in the northern, maritime climate typical of Nova Scotia. WSP Canada’s project engineers worked with Orenco Systems®, Inc. and Infiltrator distributor, Atlantic Purification Systems Ltd., to design several of the neighborhood wastewater treatment systems.

The initial neighborhood system, serving 50 single family and semi-detached homes, is designed to treat a peak flow of 51,200 litres per day of residential sanitary wastewater. It includes a watertight septic tank effluent pump (STEP) pressurized effluent sewer collection system that delivers primary effluent via small-diameter mainlines to an AdvanTex® AX100 secondary wastewater treatment plant. Treated effluent from the AX100 system is directed into the dispersal system dosing tank where it is pumped, on atimed and intermittent basis using pressurized micro-dosing, to a multi-celled, soil dispersal system that incorporates Infiltrator Quick4™ Plus Standard Chamber laterals in an area bed arrangement. The area beds provide on-site secondary effluent dispersal and treatment in two cells, each with five zones. A hydraulic distributing valve at the head of each cell automatically and sequentially directs the pumped flow to the appropriate zone.

The AdvanTex AX100 and Infiltrator treatment systems were selected because of the low operation and maintenance requirement of these passive treatment processes. Infiltrator and Orenco manufacture components that are pre-engineered, robust, and designed to be readily accessible for inspection, maintenance, removal and/or repair as required. The dispersal field, for example, incorporates cleanouts and pressure testing components to facilitate periodic inspection and monitoring of system conditions.
AdvanTex AX100 packed-bed textile filters are passive filtration and biological treatment systems, with high loading rates resulting in a footprint that is several times smaller than traditional sub-surface contour beds or sand filter treatment options. The modular nature of the AX100 textile filters allows developers to defer infrastructure costs by minimizing initial system size and adding modular treatment capacity to accommodate build out as the development grows.

The Infiltrator chambers simplify large bed construction, while providing savings on traditional materials and associated transportation costs. The chamber beds provide improved maintenance access and additional storage compared to traditional methods. The open bottom chamber system design preserves the infiltrative capabilities of the soils, which is especially helpful on larger sites where construction traffic is common.

To minimize impact on usable and buildable areas of the resort, most system tankage, treatment filters, the control building, and ancillary equipment for each neighborhood are in the distributed treatment plant area. The dispersal fields are located directly adjacent to the treatment plant. A small control building houses electrical power distribution and system control panel, the flow meter, and associated miscellaneous maintenance equipment. This facilitates safe and easy access to electrical and controls equipment during all weather conditions.

The system is controlled by an Orenco TCOM real-time remote telemetry panel that is capable of 24/7 monitoring and data logging of key equipment and plant conditions. It can email alarm notifications to operators and provide real-time remote control and adjustment by the operator from any Windows-based PC with an internet connection.