The test to apply for an affordable housing appeal under C.G.S. §8-30g is not whether a planning and zoning commission's decision was reasonable, but whether it was necessary. The plaintiff, Eureka V, LLC, appealed from the Superior Court's judgment sustaining, in part, the plaintiff's appeal from the Ridgefield planning and zoning commission's decision approving, in part, the plaintiff's modified affordable housing applications. The plaintiff claimed that the court improperly upheld that portion of the defendant commission's decision imposing conditions effectively banning development of affordable housing in a public watershed area of the property, including prohibiting municipal sewer line extensions through the area. The Appellate Court reversed the judgment and remanded the matter concluding that the defendant failed to meet its statutory burden of establishing that the restrictions imposed were necessary to protect a substantial public health or safety interest pursuant to C.G.S. §8-30g(g)(1)(A). Statutory aggrievement pursuant to C.G.S. §8-30g was minimally established. The defendant accepted with modifications the zoning changes sought, setting the stage for development of the property as an affordable housing site, while attempting to protect a public drinking water source by concentrating development in nonwatershed areas. Any substantial risk to the public's legitimate interest in maintaining safe and healthy drinking water could outweigh the need for affordable housing. Sufficient evidence was found in the record to support the defendant's initial determination that the granting of the applications as submitted would present more than a mere theoretical possibility of a specific harm to the public's substantial interest in maintaining a safe and health  drinking water supply. The defendant was justified in making modifications. But, the defendant failed to meet the additional burden imposed by C.G.S. §8-30g to prove that the modifications chosen were necessary to protect that public interest. Although the choice to ban development in the watershed area and to increase development in the nonwatershed areas as an offset may have been reasonable, the test under C.G.S. §8-30g is not whether the decision was reasonable, but whether the decision was necessary. Evidence showed that allowing a lower density development could adequately protect the public's interest in safe drinking water. The outright ban was not necessary. The ban on sewering also was not shown to be necessary to protect the public's interest in safe drinking water.