Which of the following improvements in water efficiency would most likely need to be researched to confirm their legality for a project?

The option regarding alternative water sources requires research to confirm legality because such sources can encompass a variety of non-potable options, including graywater and treated wastewater. Different jurisdictions have varying regulations and standards regarding the use of these water sources, which can affect whether they are permissible for a project. Understanding local codes and policies is crucial before implementing systems that utilize alternative water sources, as they often involve complex legal and health considerations.

In contrast, recycling rainwater may also need some degree of regulatory review, but it is generally more accepted and has established guidelines in many areas. Installing low-flow fixtures typically follows standard plumbing codes that don’t require significant legal scrutiny. Similarly, drip irrigation systems are widely accepted as water-efficient practices and generally do not involve the same level of legal considerations associated with alternative water sources. Thus, the nature of alternative water sources makes it essential for project teams to research the specific regulations that apply to their use.