Adverse Effect Findings and What Mitigation Can Require

An adverse effect finding is the hinge of federal historic review. Before it, the project is being described. After it, the project is being negotiated. The finding is not a judgment that a project is bad; it is a technical conclusion that specific qualities will be diminished, and understanding those qualities is what allows a design to avoid the finding altogether.

The criterion and how it is applied

Section 800.5 states the test. An adverse effect is found when an undertaking may alter, directly or indirectly, any of the characteristics of a historic property that qualify it for inclusion in the National Register in a manner that would diminish the integrity of location, design, setting, materials, workmanship, feeling or association.

The regulation then adds a sentence that expands the analysis considerably. Adverse effects may include reasonably foreseeable effects caused by the undertaking that may occur later in time, be farther removed in distance, or be cumulative. This is why a road widening is assessed for the development it induces, why a utility connection is assessed for what it makes buildable, and why a series of small projects can produce a finding that none of them would produce alone.

Two words in that sentence do most of the work. May makes the test one of potential rather than certainty, so a project with an uncertain outcome is assessed on what it may do. Qualify limits the inquiry to the characteristics that made the property eligible, which is why the eligibility record matters so much later. A building listed for its structural engineering is not adversely affected by a paint color, and a district listed for its streetscape can be adversely affected by a project that never touches a single wall.

The enumerated examples

The regulation gives examples rather than an exhaustive list. Physical destruction of or damage to all or part of a property is the obvious one. Less obvious is alteration, including restoration, rehabilitation, repair, maintenance, stabilization, hazardous material remediation and the provision of accessible entrances, where the work is not consistent with the Secretary of the Interior's Standards for the Treatment of Historic Properties.

Those examples repay close reading because they contradict intuition. Nothing in them requires the property to be touched. Nothing in them requires the effect to be permanent. And two of them describe conduct that a well-intentioned owner or agency would regard as protective, namely repair carried out to the wrong standard and a sale intended to find a better steward. The regulation is measuring the qualities that qualified the property, not the motives of the person acting.

The remaining examples reach further. Removal of a property from its historic location. Change in the character of the property's use, or of physical features within its setting that contribute to significance. Introduction of visual, atmospheric or audible elements that diminish integrity. Neglect that causes deterioration, with an exception for properties of religious and cultural significance to Indian tribes where deterioration is a recognized quality. And transfer, lease or sale out of federal ownership without adequate and legally enforceable restrictions to ensure long-term preservation.

Avoiding and conditioning the finding

The regulation permits a finding of no adverse effect where the undertaking's effects do not meet the criterion, or where conditions are imposed that will avoid the effect. Conditioned findings are used constantly. A project that agrees to retain a facade, to move a staging area off a site, to lower a structure, or to follow the treatment standards receives the finding on those terms, and the terms become binding.

The sequence matters. A conditioned no adverse effect finding avoids the notification of the Advisory Council and the negotiation of an agreement document, which is a real schedule saving. Whether that route is available depends on identification and the study boundary, discussed in how eligibility and the area of potential effects are determined.

What mitigation actually commits a sponsor to

Resolution under section 800.6 proceeds in a stated order of preference: avoid the effect, minimize it, or mitigate it. Mitigation is what remains when the harm is accepted. The measures are written as stipulations, assigned to a responsible party, given a schedule, and made subject to reporting so that the agency can confirm performance.

What mitigation may require is bounded in one direction and open in the other. It must relate to the effects of this undertaking, and it must be within the sponsor's or agency's authority to deliver, so a stipulation requiring a change in local zoning is unenforceable however desirable. Beyond that the parties can agree to nearly anything: funds for a survey, an endowment for repairs, an interpretive program, a covenant on another building, training positions on the excavation. The negotiation is genuinely a negotiation, and sponsors who arrive with nothing to offer beyond documentation find it a long one.

The durable measures are the ones that survive the project team. A recorded easement conveyed to a qualified holder outlasts every person who negotiated it, which is why it appears so often in agreements and why its mechanics deserve attention in how preservation easements bind successive owners. Where the mitigation involves rehabilitating a building rather than recording it, the same treatment standards reappear in the certification route described in the rehabilitation credit and its certification steps. And where a stipulation requires a building to be maintained, the enforcement problem is the one addressed in demolition by neglect and how it is enforced.