Renewing the Public Realm

What’s a brownfield?

By admin ⋅ July 10, 2008 ⋅  Email this post ⋅  Print this post ⋅ Post a comment

WHAT CRITERIA DO YOU CONSIDER when choosing a site for a building project? Prime location? Good price? Clean, well-manicured surroundings?

Have you ever considered a brownfield for your project? You may not realize it but perhaps your project is being built on a brownfield.

What is a brownfield? It’s an abandoned, underused industrial or commercial site, where development is complicated by real or perceived environmental contamination. It may be a neglected but harmless commercial property or a highly toxic site.

Damaged sites

Brownfields are sites damaged by previous building or industrial activities. These sites may require extensive remediation to remove toxins such as lead, asbestos, gasoline, diesel, motor oil, pesticides and a host of other environmental contaminants.

The contaminants may be found in the soil, sediments and sludge (accumulation of dirty oil). They may also be found in groundwater, surface water and leachate (liquid runoff from dumps seeping untreated into groundwater).

Damage may also be caused by drainage for farming or decades of overgrazing by livestock.

These are some of the challenges that contaminated brownfields pose for would-be developers, investors and designers because of their potentially harmful effects.

Challenge

Reusing and rehabilitating damaged land instead of developing virgin land is a sustainable practice. It reduces pressure on undeveloped land resource.

The development of brownfield remediation technology in developed countries has also prompted the cleanup and reuse of brownfields.

In almost all countries there are many cases of prime development areas like riverfront sites, industrial waste sites, abandoned warehouses and others with access to public transportation and inner-city core activity. These sites could be redeveloped into mixed housing and commercial projects, or community gardens and orchards, and many other land uses.

What can be done?

Potential brownfield developers must first consider each site for their advantages and liabilities, and assess the extent of environmental cleanup work needed to make the site healthy for future users. The amount of cleanup will depend on the level of risk.

Architects play an important role at the start of a construction project. They have the planning, facilitation and coordination skills to see the big picture.

Planning process

The first step in the brownfield process is visual inspection of the current use of the land and a study of its past use through documents and interviews. If the findings show signs of possible toxic materials in the land like lead, arsenic or asbestos, the process becomes more intensive. Sampling of the soil, soil gas, ground water, surface water or sediment is made to determine the type and quantity of contaminants.

A work plan is then made on how the site will be cleaned up for the intended use. In the United States, standards prescribed by the Environmental Protection Agency or EPA are followed, and once the work plan is approved, the developer may avail of tax credits, loans or grants. The cleanup of a particular site can be monitored at the local level. New owners of brownfields may not be liable for contaminants created in the past, but they have to comply with certain requirements prescribed by law.

Remediation techniques

There are several ways to apply remediation techniques in a contaminated brownfield depending on the type and location of the contaminant.

Remediation techniques include removal of contaminants from the site; others are treated on site, while others are contained on site so as not to spread.

In the case of diesel-contaminated soil, some of the shallow soil is excavated and aerated so that volatile hydrocarbons will be released before the soil is removed from the site. The remaining soil is covered with several feet of clean fill.

An area with heavy-metal contamination may be designated for surface parking.

Remedies for types of contaminants found at typical brownfield sites are now the subject of a new field of engineering called environmental engineering. New technology is targeted to sample, analyze and clean up environmentally contaminated areas.

Our country is going through rapid urbanization and the need for more legislation on environmental protection is upon us.

Brownfield redevelopment is very much a part of the effort to reduce our ecological footprint, which is the impact of human activity on the land and its finite resources. The most important consideration however is public safety and health.

Amado de Jesus, Philippine Daily Inquirer