Residual impacts are, in the simplest sense, the consequences of any action. In a business context the term usually refers to either residual impacts upon stakeholders or the environment. Some industrial activities, such as road building, have both positive residual impacts to stakeholders and lasting environmental consequences. One of the reasons to examine residual impacts of major business actions is to help mitigate negative consequences and take credit where credit is due for positive contributions to the community.
Residual Impacts and Public Safety
When deciding the importance of the various residual impacts of a project, the first area to examine is that of public safety. The question becomes whether the project is of significant risk to the public, and, if so, how can that risk be minimized. Acting in the interest of the public is not only a matter of good corporate citizenship and community stewardship but also a pragmatic measure as well since projects that harm the public may result in lawsuits and, in extreme cases, criminal proceedings. In cases where the long-term impact of a project is unclear, the onus is on the company to refer to qualified environmental consultants – internal or external – to ensure that there are no severely negative environmental consequences from the project. While individual companies bear much of the responsibility for environmental impacts, legislators provide the regulatory framework that helps tell private companies what specific actions to avoid.
Positive Residual Impacts
Positive residual impacts are the result of a project or action that, while secondary to the main purpose of the project, are nonetheless positive for the surrounding community. For example, if a company planted trees in a local park as a carbon offset, the primary intended impact is improved green space and fresh air; however, if those trees were cherry trees, they might bear fruit that the community could pick and preserve for the local homeless shelter, which would be a positive residual impact. Positive residual impacts are, however, not as wildly publicized or even noticed as much as negative ones since positive residual impacts generally don't require much community attention.
Negative Residual Impacts
Negative residual impacts are what most people think of when the phrase “residual impact” is mentioned and refers to problems unintentionally generated by the primary project or action. For example, building a highway, while beneficial to many of a city's residents, could have negative residual impacts in the form of smog and noise pollution. Some negative residual impacts are manageable disruptions; the noise of a highway that disturbs some residents is a small price to pay for convenient access to shipping routes and the jobs those shipping routes bring.
By contrast, some negative residual impacts require corrective actions down the line. As an example, some industrial manufacturing plants may have released substances into a local river or lake that are now known as toxins but were thought to be inert at the time. To maintain public health and safety, a costly dredging of the river or lake may be necessary. If the company was breaking a safety law at the time, it may be accountable for the cost of the cleanup. Even if a company wasn't breaking the law, it may volunteer to participate in the cleanup to maintain a positive public image.
Dealing With Unforeseen Negative Residual Impacts
Responding to problematic residual impacts means that companies and individuals responsible for the problem must be held accountable. Perfectly acceptable is for a company to investigate the validity of negative impact claims, but if the claims hold water, the company needs to accept responsibility. For example, if a company promised that the construction of a new airport wouldn't hurt nearby property values, but the airport ultimately did damage property values due to a higher than estimated noise level, the company may opt to offer a voluntary out-of-court settlement. A failure to take responsibility sooner rather than later might lead to a series of costly and publicized lawsuits.