Ottawa's planning committee approved the rezoning of a 386-home subdivision in Barrhaven on Thursday, and allowed more flexible placement of a future school after the Ottawa-Carleton District School Board expressed concerns.
The seventh and eighth phases of Tamarack Homes's The Meadows community would be located south of Cambrian Road.
Tamarack plans to build 116 single-detached homes, 16 semi-detached houses, 204 townhouses, and 50 back-to-back townhouse units.
Michelle Taggart, vice-president of planning and development for Tamarack, explained at the committee meeting that the company had to redesign its original plan for the subdivision to "raise everything up," after the city expressed "geotechnical" concerns about the depth of the pipes that would be installed underneath.
But in starting over, Tamarack chose to set aside land for a future school in the centre of the subdivision, beside a big park, instead of on the edge of the property. The Ottawa-Carleton District School Board (OCDSB) was concerned with its new location, and wrote to the city Wednesday before the meeting.
"The OCDSB wanted to ensure that the proposed school site and zoning requirements would provide flexibility in siting the school to help minimize costs of construction," spokesperson Darcy Knoll wrote to CBC News in an email.
"There are sensitive marine clay soils throughout the subdivision," said Taggart, explaining why the board worried about higher costs of building on clay soil, a heavy type of soil that holds a high amount of water.
The planning committee agreed to allow zoning for the school to be located on either its proposed site or the one intended for the park, where soils are slightly better.
No concerns about nearby landfill toxins
Lily Xu, the city's manager of development review for the south end, later explained to CBC why the subdivision site had to be raised by two metres.
Xu said during the engineering process, the contractor uncovered an artesian area where the groundwater was under pressure.
"Raising the site was determined to be the most suitable alternative to minimize the impact on the groundwater and any potential migration of the plume off the Trail Road [landfill]," wrote Xu.
Concerns that those toxins below the city's landfill — called a leachate plume — might move off-site first came up when a separate, nearby development received approval this past spring.
Given how close developments in Barrhaven are getting to the landfill, the city recently had a consultant model the groundwater, and consider any risks that nearby digging could make it move off the dump site.
"While we are still in the process of evaluating various long-term scenarios, the preliminary findings show no major concerns with this development proceeding," wrote Shelley McDonald, the city's director of solid waste, about the Tamarack subdivision.
Given the subdivision's location less than one kilometre from the landfill, houses will have warning notices on the property title that note those operations could cause odours, and the homes must have air conditioning units.
As for the perennial traffic problem in Barrhaven south of the Jock River, this subdivision is expected to see more vehicles empty onto Cambrian Road because the main artery alongside it — a realigned Greenbank Road — has been delayed and not built yet.
The rezoning still needs city council's approval on Oct. 14.