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GUIDE 4: The Importance of "Substantive" Environment Impact Comments

In this basic guide we attempt to explain what are "Substantive" Environment Impact Comments, and why they are important in any environment impacts public consultation process.



Substantive comments are those that suggest the report is flawed in a specific way. Generally they challenge the accuracy of information presented, challenge the adequacy, methodology or assumptions of the environmental or social analysis (with supporting rationale), present new information relevant to the analysis, or present reasonable alternatives (including mitigation) other than those presented in the document.

Such substantive comments may lead to changes or revisions in the analysis or in one or more of the alternatives.


Keep in mind that comments that challenge the document, these comments must be supported by verifiable data, reputable studies, or other information such as maps, photos, and well-documented personal experience. Take into consideration as well, that any comment that simply reflects an opinion about the project will not be addressed and taken into account.


For example, a comment that states, “I don’t like the project,” or “ I oppose any oil & gas exploration in Portugal on principle” typically results simply in a response of “Comment Noted and Discarded”.


Substantive comments that are backed by factual support, sometimes lead to changes in the final EIA and in the project. The comments should be written in a manner that requires the lead agency and the government to respond. To have a significant impact on the environmental impact reporting process, comments must point out errors, inconsistencies, omissions of data or analyses, conclusions not based on evidence, or failures to provide discussion required by the various underpinning legislation.

The agency needs to respond adequately to such substantive comments prior to certification of the final EIA. Failure to do so would provide the basis for a legal challenge, and if the court agreed with the challenge, the EIA or the process would be found invalid.


Here’s a few examples

Be specific: The more specific your comments are, the more they will require the lead agency to consider and respond to them.

Don’t say: “this project will increase traffic”

Instead say: “this project will increase traffic during construction at the corner of “X street” in the vicinity of a school which already has traffic problems. The report should analyse the project’s impact on traffic circulation and safety, especially regarding school children near this site.” Supply some evidence, if you can, even if it simply personal experience or observations.

Don’t say: “I’m concerned about visual impacts of this project.”

Instead say: “I often view the project site when travelling (in … specific area) and consider the site visually prominent in the community”


  1. Look for inconsistencies in the document: If they use one set of numbers for traffic counts in the traffic section and another in the noise section, the two sections must be made consistent.

  2. Look for errors in logic: If a proposed mitigation measure doesn’t have an identified site, or for some other reason looks like a fig leaf rather than a serious effort to address a problem, say so.

  3. Focus on the sufficiency of the report in identifying and analysing the possible impacts of the project on the environment.


For example: Is there a local public facility required to serve the new development that has not been identified as potentially having an impact? If you believe an area has been insufficiently analysed, include that in your comment and request that it be analysed.

Sample Comment: Traffic impact analysis is worthy of particular attention. The introduction of hundreds of trucks 24X7 in poor quality regional roads will compound existing conditions in the project vicinity. Adequate analysis of project impacts on the local and regional traffic infrastructure must be a focus of the report. This can trigger questions regarding road quality (increased potholes), traffic flow, air quality, noise, and aesthetics.


Avoid starting comments with statements of support, followed by concerns.

When you write, “I support this project, but I have a number of concerns…” your comment may be logged as a “Letter of Support” even though you may have written 10 pages on why you are not satisfied with the report document. Your comment does not need to be “balanced” between the part of the project you favour and those that you concern you – simply state your concern.

Separate your concerns into clearly identifiable paragraphs / headings and keep a tight focus on each separate issue. Don’t mix topics.




Disclaimer: The guidelines in this article is intended to serve as a guide and is not intended to be legal advice. Please seek professional help from a lawyer if you have legal questions or concerns.


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