4.6.2.2. Necessary Support.Of course, the mere fact of a partial acquisition will not necessarily entitle a landowner to damages.752 It may well be “that while there has been a severance in the legal sense such severance has caused no compensable damage to the market value of the properties not taken.”753 

And legally compensable damages can only be considered if proved: as with any element affecting value, damage to the remainder (i.e., diminution in value) can never be assumed but must always be fully supported by the facts of each situation.754 Damage that is “vague and speculative in character” or premised on “possibilities more or less remote” cannot be considered.755 As a result, it is improper to use damage as a catchall, simply stating an amount without specifying the basis for the opinion. One court criticized parties who failed to furnish factual data to support claimed diminution in value to the remainder as follows: “Not only were the opinions of their experts based largely on speculation and conjecture, but these witnesses totally disregarded available evidence of comparable sales before and after the taking of the easement.”756 In short, damage is “compensable only if the landowner incurs a direct loss reflected in the market place that results from the [acquisition].”757 Moreover, not merely damage, but causation must be proved: for compensation to reflect diminution in value to the remainder, the “landowner must demonstrate that the taking caused the . . . damage[ ].”758 

Conjecture and Speculation.Of course, even potentially compensable damages must be disregarded if based on mere speculation and conjecture.759 Thus, the federal courts have barred consideration of damages that are not supported by actual market evidence.760 These items must be disregarded in determining market value for federal acquisitions because consideration of such elements would “add to just compensation something that the law does not allow.”761 Elements that have been excluded from consideration because they were not shown to be reasonably probable run the gamut from an assertion that “buyers would suddenly become fearful of explosive hazards” due to a safety buffer zone “created to ease public fear of explosive hazards”762 to claimed damage due to the threat that “marauding bears” would “specifically foray from [a] newly created park” to attack young-growth trees on remainder property.763 

Anticipated Physical Invasion of the Remainder.Damage due to anticipated physical invasion of the remainder resulting from the intended use of the land acquired is not compensable in federal acquisitions.764 For example, in the federal acquisition of a flowage easement for construction of a reservoir, an opinion of market value must disregard any damage to the remainder from anticipated wave action above the line of the acquisition during periods of high winds.765 To do otherwise would in essence expand the government’s acquisition, which neither appraisers nor landowners—nor the courts—have the power to do.766 

Use of Others’ Lands.Similarly, diminution in value of a landowner’s remainder caused by the United States’ use of other lands is not compensable and cannot be considered in valuations for just compensation purposes.767 The Supreme Court created this rule in Campbell v. United States, reasoning: 

If the former private owners [of adjacent property] had devoted their lands to the identical uses for which they were acquired by the United States . . . , they would not have become liable for the resulting diminution in value of [the remainder] property. The liability of the United States is not greater than would be that of the private users.768

The Ninth Circuit created a narrow exception to the Campbell rule in United States v. Pope & Talbot, Inc. to allow compensation for damage resulting from the use of another’s property in limited circumstances.769 Thus, in the Ninth Circuit, damage to the remainder resulting from the use of others’ property may be considered if (1) the part acquired is indispensable to the government project; (2) the part acquired contributes substantially (not inconsequentially) to the project and the resulting damage; and (3) damage to the remainder due to the use of the part acquired is inseparable from damage to the remainder due to the government’s use of its adjoining land in the project.770 For example, consider a partial taking of a tract for construction of a contaminated soils depository, which would be constructed partly on the property taken and partly on property acquired from others: it might not be practical to separate the diminution in value of the remainder caused by the use of the property acquired from that caused by the use of lands acquired from others. In such situations, the appraiser should seek legal guidance. The Ninth Circuit’s exception to the Campbell rule has not been adopted by other federal courts,771 and even in the Ninth Circuit is rarely invoked.772 And as the Ninth Circuit made clear in subsequent rulings, regardless of the Pope & Talbot exception, damage is “compensable only if the landowner incurs a direct loss reflected in the market place that results from the [acquisition].”773 Moreover, causation must be proved: a “landowner must demonstrate that the taking caused the . . . damage[ ].”774 

Stigma, Fear, and Contamination.If stigma or fear of a “hazard would affect the price a knowledgeable and prudent buyer would pay to a similarly well-informed seller, diminution in value caused by that fear may be recoverable as part of just compensation.”775 The threshold question is not whether the fear or stigma is rational or well-founded, but rather whether and to what extent it affects the market.776 There must be evidence “connecting the safety issue to the real estate market.”777 Moreover, it is improper to simply assume that a hazard, or the fear of a hazard, has an effect on market value. As the Ninth Circuit explained in a condemnation for construction of high-voltage transmission lines and potential fears of electromagnetic fields (EMFs): 

In the absence of relevant and probative evidence, a [fact-finder] could only speculate concerning the effect of a particular measurement on public perception. Perhaps the general public, unschooled in the significance of the milligauss, is afraid of actual EMFs in any quantity, so long as they come from a big power line. Or perhaps the levels of EMFs that exist on [the subject property] would even ease public fears in the marketplace. There is simply no way for a [fact-finder] to tell. Without any evidence . . . that higher levels of EMF generate higher levels of buyer aversion and lower sale prices, [evidence] about specific EMF levels has little to no probative value.778 

Uniform Appraisal Standards for Federal Land Acquisitions / Legal Foundations For Appraisal Standards 

Further, fear or stigma associated with anticipated damage may also be recoverable if it would affect the market price a knowledgeable and prudent buyer would pay for the property on the date of value.779 Causation between the stigma or fear and the government’s acquisition must be shown.780 And diminution in value resulting from fear or stigma due to the actions of a third party or to pre-existing conditions cannot be considered.781 For these reasons, appraisers must obtain clear written instructions regarding appropriate consideration of environmental contamination or other hazards, as discussed in Section 1.2.7.1.782 159