The Ontario Municipal Board's hearing on the fate of the planned Airport Employment Growth District, popularly referred to as the Aerotropolis, has major implications for the future of Hamilton.

In 2010, days before the most recent municipal election, council passed the plan to develop approximately 700 hectares of farmland around Hamilton International Airport. Now, two groups — Environment Hamilton and Hamiltonians for Progressive Development — are taking on the city in the seven-day hearing that began Jan. 21 in an attempt to prevent the project from coming to fruition.

Like the decision over the where to locate the Pan Am stadium, it's another debate over the merits of greenfield versus brownfield development, suburban expansion versus urban intensification.

Regardless of who's right, Hamiltonians should pay attention to how the board rules. Here are a four reasons why:

1. Cost: $350 million

The city has said developing the land around the airport would cost taxpayers at least $350 million, coming at a time when the city has an annual infrastructure deficit of over $150-million.

Environment Hamilton director Don McLean, who opposes the Aerotropolis, said the project threatens to be a serious drain on the city finances.

"We need stop sprawl, we need to intensify what we have…so we're not continuously spending more money to maintain [the new infrastructure] over the long haul."

"I think the fundamental part of sprawl, at least from the layman's perspective, is that it's incredible expensive to pay for."

2. Economic growth: $70 million in tax revenue by 2031

On the other hand, the Aerotropolis could serve as a huge economic boon to the city. The city predicts the land, if developed, would generate $70 million in annual tax revenue by 2031 and attract reams of jobs.

"This land is of strategic importance in terms of employment area for the whole city," Guy Paparella, director of growth planning for the city, told CBC Hamilton earlier in January.

The growth plan would also reduce local dependence on commuting and take advantage of airport infrastructure, said Guy Paparella, the city's director of growth planning.

He said the project could diversify Hamilton's employment base, adding jobs in desirable fields such as advanced manufacturing and transportation.

3. Food security

Most of the 700 hectares comprising the Airport Employment Growth District is considered prime farmland. Consequently, developing it would deprive Hamilton of some of its capacity to grow its own food — and thus breach Hamilton's Vision 2020 strategic plan, which aimed to promote local agriculture and discourage urban sprawl.

This would represent a terrible loss for the region, said McLean, especially at a time when fuel prices are rising, resulting in increasing food costs, and when climate change threatens to diminish the global food supply.

"My concern, in part, is the sacrifice of agricultural food land in a situation when food security on a global scale is obviously becoming a significant problem."

4. More conflict

The upcoming OMB hearing raises the spectre of the continuing escalation of the fight between those who oppose the Aeropolis and those who wish to see its speedy approval. Expect both sides to be extremely vocal about the board's decision, whatever the result.

The OMB hearing began Monday, Jan. 14 at the Hamilton Convention Centre, and are expected to finish by Friday, Jan. 25.