Coal

Professor Tom Roberts

Spring 1999

COAL

Then the coal company came with the world's largest shovel and they tortured the timber and stripped all the land, and they dug for their coal til the earth was forsaken and they wrote it all down to the progress of man. . .

Oh, Daddy, won't you take me back to Muhlenberg County, down by the wide river where Paradise grows. I'm sorry my son but you're too late in asking, Mr. Peabody's coal train has hauled it away.

From folksong by John Prine

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Rising from the Plains (1986)

John McPhee

In Rising from the Plains, McPhee writes of his travels through Wyoming with geologist David Love. In the following excerpt he provides a view of the creation of coal, the process of strip mining, covers some of the environmental problems associated with mining and with the production of electricity, describes the prospects of getting oil from shale, and ponders the implications of trans-basin diversions of water - all in all, a fitting end to this chapter on energy fuels and an introduction to the next chapter on water.

At Points of Rocks, a hamlet from the stagecoach era, . . . we left the interstate . . . and went north . . . and soon curved into a sweeping view: east over pastel buttes into the sheep country of the Great Divide Basin, and north to the white Wind Rivers over Steamboat Mountain and the Leucite Hills (magmatic flows and intrusions, of Pleistocene time), across sixty miles of barchan dunes, and, in the foreground--in isolation in the desert--the tallest building in Wyoming. This was Jim Bridger, a coal-fired steam electric plant, built in the middle nineteen-seventies, with a generating capacity of two million kilowatts--four times what is needed to meet the demands of Wyoming. Twenty-four stories high, the big building was more than twice as tall as the Federal Center in Cheyenne, which is higher than Wyoming's capitol dome. Rising beside the generating plant were four freestanding columnar chimneys so tall that they were obscured in cumulus from the cooling towers, which swirled and billowed and from time to time parted to reveal the summits of the chimneys, five hundred feet in the air. "This place is smoking the hell out of the country," Love said. "The wind blows a plume of corruption. In cold weather, sulphuric acid precipitates as a yellow cloud. It's not so good for people, or for vegetation. Whenever I think of this plant, I feel sadness and frustration. We could have got baseline data on air and water quality before the plant was built, and we muffed it." He blames himself, although at that time he had arsenic poisoning from springwater in the backcountry and was sick for many months.

The idea behind Jim Bridger was to ship energy out of Wyoming in wires instead of railway gondolas. Ballerina towers, with electric drapery on their out-stretched arms, ran from point to point to the end of perspective, relieving pressure on the Oregon-Idaho grid. The coal was in the Fort Union formation--in a sense, the bottom layer of modern time. Locally, it was the basal rock of the Cenozoic, the first formation after the Cretaceous Extinction--when the big animals were gone, but not their woods and vegetal swamps. Wyoming had drifted a few hundred miles farther north than it is now, and around the low swamplands were rising forest of oak, elm, and pine. The terrain was near sea level. Mountains had begun to stir--Uintas, Wind Rivers, Owl Creeks, Medicine Bows--and off their young slopes they shed the Fort Union, its muds burying the compiled vegetation, cutting off oxygen, preserving the carbon. As the mountains themselves became buried, the fallen vegetation in the thickening basins was ever more covered as well, to depths and pressures that caused it to become a soft and flaky sub-bituminous low-rent grade of coal, a nonetheless combustible low-sulphur coal. By the middle nineteen-seventies, nature had removed a mile of overburden, and had only sixty feet to go. At that point, something called the Marion 8200, an eight-million-pound landship also known as a walking dragline, took over the job.

The machine was so big it had to be assembled on the site--a procedure that required fourteen months. Now working within a mile or two of the generating plant, it could swing its four-chord deep-section boom and touch any spot in six acres, its bucket biting, typically, a hundred tons of rock, and dumping it to one side. The 8200 had dug a box canyon, its walls of solid coal about thirty feet thick. The inside of the machine was painted Navy gray, and had non-skid deck surfaces, thick steel bulkheads, handrails, and oval doors that looked watertight. They led from compartment to compartment, and eventually into the air-conditioned sanctum of Centralized Power Control, where, lined up in ranks, were electric motors. The foremost irony of this machine was that it was far too large and powerful to operate on diesel engines. Although the chassis was nine stories high, it could not begin to contain enough diesels to make the machine work. Only electric motors are compact enough. Out the back of the machine, like the tail of a four-thousand-ton rat, ran a huge black cable, through gully and gulch, over hill and draw, to the generating plant--whose No. 1 customer was the big machine.

Once every couple of hours, the 8200 walked--raised itself up on its pontoonlike shoes and awkwardly lurched backward seven feet, so traumatically compressing the dirt it landed on that smoke squirted out the sides and the ground became instant slate. This machine--with its crowned splines, its precise driveline mating, its shop-lapped helical gears, its ball-swivel mounting of the boom-point sheaves, its anti-tightline devices and walking-shoe position indicators--had unsurprisingly attracted the attention of Russian engineers, who came in a large committee to see Jim Bridger, because they were about to build twenty-five similar generating stations in one relatively concentrated area of Siberia, which, they confided, closely resembled Sweetwater County, Wyoming.

This strip mine, no less than an erupting volcano, was a point in the world where geologic time and human time had intersected. Ordinarily, the close relationship between the two is masked: human time, full of beepers and board meetings, sirens and Senate caucuses, all happening in microtemporal units that physicists call picoseconds; geologic time, with its forty-six hundred million years, delivering a message that living creatures prefer to return unopened to the sender. In this place, though, geology had come up out of its depths to join the present world, and, as Love would put it, all hell had broken loose. "How people look at it depends on whose ox is being gored," he said. "If you're in a brown-out, you think it's great. If you're downwind, you don't. Wyoming's ox is being gored."

. . .

For a steam-driven water-cooled power plant, this one seemed to have a remarkably absent feature. It seemed to be missing a river. The brown surrounding landscape was craquelure of dry gulches. In one of them, though--a desiccated arroyo called Dead Man Draw--was a seventy-five-acre lake, fringed with life rings, boats, and barbecue grills. At the rate of twenty-one thousand gallons a minute, Jim Bridger was sucking water from the Green River, forty miles to the west. To cool an even drier power station, some hundreds of miles away in northeast Wyoming, a proposal had been made to pump Green River water over the Continental Divide to the Sweetwater River, which runs into the North Platte, from which the water would be pumped over a lesser divide and into the Powder River Basin. Love said, "That would destroy the whole Sweetwater regimen, destroy the Platte, and destroy the Powder River, all for coal in the Powder River Basin--a slurry pipeline or something of the sort. It's very much on the books. If they go in for the gasification of coal, they're going to need it. It's known as the trans-basin diversion of the Green River. The water has fluorine in it. Wherever it gets into the ground, it can pollute the water table in ten to fifteen years. The river also picks up sodium from trona. In the town of Green River, the sodium in the drinking water greatly exceeds E.P.A. standards. If they decide to pipe the water over the Continental Divide, water quality could be lowered in the Powder River Basin to the point of needing a desalinization plant."

Distinct in the long suite of cuts at Green River were the so-called mahogany ledges, where oil shale is particularly rich. They looked less like wood than like bluish-white slabs of thinly bedded slate. Oil shale always weathers bluish white but is dark inside, and grainy like wood. The thinner the laminae the higher the ratio of organic material. The richest of the dark oleaginous flakes--were fifteen-thousandths of a millimetre thick. Love dropped some hydrochloric acid on the rock, and the acid beaded up like an arching cat. "It converts to high-paraffin oil. It's not like Pennsylvania crude."

To mining engineers, oil shale had presented an as yet unsolved and completely unambiguous problem: how to remove the shale without destroying the face of the earth. So far, three principal methods had been considered. One was to strip-mine it, crush it, separate the oil, then smooth out the tailings--a process that could result in the absolute rearrangement of twenty-five thousand square miles. Another was to go underground, excavate a percentage of the rock, and refill the caverns with tailings. That was known as the "modified in situ" approach. And finally someone thought of drilling a hole, pumping in propane, and starting a fire. The heat would cause liquid oil to run out of the sale. The oil could be forced up through another well before the fire destroyed it. A burn would not, like a clinker fire, continue indefinitely. If oxygen was not fed to the flames, they would die. This was known as "true in situ" mining; and there in White Mountain, a few miles away, the federal government had been perfecting the technique. The experiments thus far had brought down the recovery cost to a million dollars a barrel. In Cheyenne one time, I saw a Peter Pan Crunchy Peanut Butter jar filled with such oil. It looked and smelled like the content of a long unemptied spittoon.

The one-and-a-half-trillion-barrel estimate was somewhat extravagant, because it included every last drop--referring, as it did, to all shale with any content of kerogen. In the richer rock--in the shales that contained from twenty-five to sixty-five gallons of oil per ton--were no more than six hundred billion barrels. That would do. That was more petroleum in place than all the petroleum produced in the world to date. Love remarked that oil shale had been "trumpeted to the skies" but, with the energy crisis in perigee, both government and industry were losing interest and pulling out. Temporarily pulling out. Sooner or later, people were going to want that shale.

John McPhee, Rising from the Plains, 181-194.

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Keystone Bituminous Coal Association v. DeBenedictis

480 U.S. 470 (1987)

STEVENS, J., delivered the opinion of the Court, in which BRENNAN, WHITE, MARSHALL, and BLACKMUN, JJ., joined. REHNQUIST, C.J., filed a dissenting opinion, in which POWELL, O'CONNOR, and SCALIA, JJ., joined.

Justice STEVENS, delivered the opinion of the Court.

In Pennsylvania Coal Co. v. Mahon, 260 U.S. 393, 43 S.Ct. 158, 67 L.Ed. 322 (1922), the Court reviewed the constitutionality of a Pennsylvania statute that admittedly destroyed "previously existing rights of property and contract." Id., at 413, 43 S.Ct., at 159. Writing for the Court, Justice Holmes explained: "Government hardly could go on if to some extent values incident to property could not be diminished without paying for every such change in the general law. As long recognized, some values are enjoyed under an implied limitation and must yield to the police power. But obviously the implied limitation must have its limits, or the contract and due process clauses are gone. One fact for consideration in determining such limits is the extent of the diminution. When it reaches a certain magnitude, in most if not in all cases there must be an exercise of eminent domain and compensation to sustain the act. So the question depends upon the particular facts." Ibid. In that case the "particular facts" led the Court to hold that the Pennsylvania Legislature had gone beyond its constitutional powers when it enacted a statute prohibiting the mining of anthracite coal in a manner that would cause the subsidence of land on which certain structures were located.

Now, 65 years later, we address a different set of "particular facts," involving the Pennsylvania Legislature's 1966 conclusion that the Commonwealth's existing mine subsidence legislation had failed to protect the public interest in safety, land conservation, preservation of affected municipalities' tax bases, and land development in the Commonwealth. Based on detailed findings, the legislature enacted the Bituminous Mine Subsidence and Land Conservation Act (Subsidence Act or the Act), Pa.Stat.Ann., Tit. 52, ' 1406.1 et seq. (Purdon Supp.1986). Petitioners contend, relying heavily on our decision in Pennsylvania Coal, that '' 4 and 6 of the Subsidence Act and certain implementing regulations violate the Takings Clause, and that ' 6 of the Act violates the Contracts Clause of the Federal Constitution. The District Court and the Court of Appeals concluded that Pennsylvania Coal does not control for several reasons and that our subsequent cases make it clear that neither ' 4 nor ' 6 is unconstitutional on its face. We agree.

Coal mine subsidence is the lowering of strata overlying a coal mine, including the land surface, caused by the extraction of underground coal. This lowering of the strata can have devastating effects. It often causes substantial damage to foundations, walls, other structural members, and the integrity of houses and buildings. * * *

Despite what their name may suggest, neither of the "full extraction" mining methods currently used in western Pennsylvania enables miners to extract all subsurface coal; considerable amounts need to be left in the ground to provide access, support, and ventilation to the mines. Additionally, mining companies have long been required by various Pennsylvania laws and regulations, the legitimacy of which is not challenged here, to leave coal in certain areas for public safety reasons. Since 1966, Pennsylvania has placed an additional set of restrictions on the amount of coal that may be extracted; these restrictions are designed to diminish subsidence and subsidence damage in the vicinity of certain structures and areas.

Pennsylvania's Subsidence Act authorizes the Pennsylvania Department of Environmental Resources (DER) to implement and enforce a comprehensive program to prevent or minimize subsidence and to regulate its consequences. Section 4 of the Subsidence Act, Pa.Stat.Ann., Tit. 52, ' 1406.4 (Purdon Supp.1986), prohibits mining that causes subsidence damage to three categories of structures that were in place on April 17, 1966: public buildings and noncommercial buildings generally used by the public; dwellings used for human habitation; and cemeteries. Since 1966 the DER has applied a formula that generally requires 50% of the coal beneath structures protected by ' 4 to be kept in place as a means of providing surface support. * * *

In 1982, petitioners filed a civil rights action in the United States District Court for the Western District of Pennsylvania seeking to enjoin officials of the DER from enforcing the Subsidence Act and its implementing regulations. Petitioners are an association of coal mine operators, and four corporations that are engaged, either directly or through affiliates, in underground mining of bituminous coal in western Pennsylvania. * * * The complaint alleges that Pennsylvania recognizes three separate estates in land: The mineral estate; the surface estate; and the "support estate." Beginning well over 100 years ago, landowners began severing title to underground coal and the right of surface support while retaining or conveying away ownership of the surface estate. It is stipulated that approximately 90% of the coal that is or will be mined by petitioners in western Pennsylvania was severed from the surface in the period between 1890 and 1920. When acquiring or retaining the mineral estate, petitioners or their predecessors typically acquired or retained certain additional rights that would enable them to extract and remove the coal. Thus, they acquired the right to deposit wastes, to provide for drainage and ventilation, and to erect facilities such as tipples, roads, or railroads, on the surface. Additionally, they typically acquired a waiver of any claims for damages that might result from the removal of the coal. In the portions of the complaint that are relevant to us, petitioners alleged that both ' 4 of the Subsidence Act, as implemented by the 50% rule, and ' 6 of the Subsidence Act, constitute a taking of their private property without compensation in violation of the Fifth and Fourteenth Amendments. * * *

III

* * *

In Pennsylvania Coal, the Pennsylvania Coal Company had served notice on Mr. and Mrs. Mahon that the company's mining operations beneath their premises would soon reach a point that would cause subsidence to the surface. The Mahons filed a bill in equity seeking to enjoin the coal company from removing any coal that would cause "the caving in, collapse or subsidence" of their dwelling. The bill acknowledged that the Mahons owned only "the surface or right of soil" in the lot, and that the coal company had reserved the right to remove the coal without any liability to the owner of the surface estate. Nonetheless, the Mahons asserted that Pennsylvania's then recently enacted Kohler Act of 1921, P.L. 1198, Pa.Stat.Ann., Tit. 52, ' 661 et seq. (Purdon 1966), which prohibited mining that caused subsidence under certain structures, entitled them to an injunction.

* * *

The company promptly appealed to this Court, asserting that the impact of the statute was so severe that "a serious shortage of domestic fuel is threatened." The company explained that until the Court ruled, "no anthracite coal which is likely to cause surface subsidence can be mined," and that strikes were threatened throughout the anthracite coal fields. In its argument in this Court, the company contended that the Kohler Act was not a bona fide exercise of the police power, but in reality was nothing more than " 'robbery under the forms of law' " because its purpose was "not to protect the lives or safety of the public generally but merely to augment the property rights of a favored few."

Over Justice Brandeis' dissent, this Court accepted the company's argument. In his opinion for the Court, Justice Holmes * * * rested on two propositions, both critical to the Court's decision. First, because it served only private interests, not health or safety, the Kohler Act could not be "sustained as an exercise of the police power." Second, the statute made it "commercially impracticable" to mine "certain coal" in the areas affected by the Kohler Act.

The holdings and assumptions of the Court in Pennsylvania Coal provide obvious and necessary reasons for distinguishing Pennsylvania Coal from the case before us today. The two factors that the Court considered relevant, have become integral parts of our takings analysis. We have held that land use regulation can effect a taking if it "does not substantially advance legitimate state interests, ... or denies an owner economically viable use of his land." Agins v. Tiburon, 447 U.S. 255, 260, 100 S.Ct. 2138, 2141, 65 L.Ed.2d 106 (1980) (citations omitted); see also Penn Central Transportation Co. v. New York City, 438 U.S. 104, 124, 98 S.Ct. 2646, 2659, 57 L.Ed.2d 631 (1978). Application of these tests to petitioners' challenge demonstrates that they have not satisfied their burden of showing that the Subsidence Act constitutes a taking. First, unlike the Kohler Act, the character of the governmental action involved here leans heavily against finding a taking; the Commonwealth of Pennsylvania has acted to arrest what it perceives to be a significant threat to the common welfare. Second, there is no record in this case to support a finding, similar to the one the Court made in Pennsylvania Coal, that the Subsidence Act makes it impossible for petitioners to profitably engage in their business, or that there has been undue interference with their investment-backed expectations.

The Public Purpose

Unlike the Kohler Act, which was passed upon in Pennsylvania Coal, the Subsidence Act does not merely involve a balancing of the private economic interests of coal companies against the private interests of the surface owners. The Pennsylvania Legislature specifically found that important public interests are served by enforcing a policy that is designed to minimize subsidence in certain areas. Section 2 of the Subsidence Act provides: "This act shall be deemed to be an exercise of the police powers of the Commonwealth for the protection of the health, safety and general welfare of the people of the Commonwealth, by providing for the conservation of surface land areas which may be affected in the mining of bituminous coal by methods other than 'open pit' or 'strip' mining, to aid in the protection of the safety of the public, to enhance the value of such lands for taxation, to aid in the preservation of surface water drainage and public water supplies and generally to improve the use and enjoyment of such lands and to maintain primary jurisdiction over surface coal mining in Pennsylvania."

* * *

Thus, the Subsidence Act differs from the Kohler Act in critical and dispositive respects. With regard to the Kohler Act, the Court believed that the Commonwealth had acted only to ensure against damage to some private landowners' homes. Justice Holmes stated that if the private individuals needed support for their structures, they should not have "take[n] the risk of acquiring only surface rights." 260 U.S., at 416, 43 S.Ct., at 160. Here, by contrast, the Commonwealth is acting to protect the public interest in health, the environment, and the fiscal integrity of the area. That private individuals erred in taking a risk cannot estop the Commonwealth from exercising its police power to abate activity akin to a public nuisance. The Subsidence Act is a prime example that "circumstances may so change in time ... as to clothe with such a [public] interest what at other times ... would be a matter of purely private concern." Block v. Hirsh, 256 U.S. 135, 155, 41 S.Ct. 458, 459, 65 L.Ed. 865 (1921).

In Pennsylvania Coal the Court recognized that the nature of the State's interest in the regulation is a critical factor in determining whether a taking has occurred, and thus whether compensation is required. The Court distinguished the case before it from a case it had decided eight years earlier, Plymouth Coal Co. v. Pennsylvania, 232 U.S. 531, 34 S.Ct. 359, 58 L.Ed. 713 (1914). There, "it was held competent for the legislature to require a pillar of coal to be left along the line of adjoining property." Pennsylvania Coal, 260 U.S., at 415, 43 S.Ct., at 160. Justice Holmes explained that unlike the Kohler Act, the statute challenged in Plymouth Coal dealt with "a requirement for the safety of employees invited into the mine, and secured an average reciprocity of advantage that has been recognized as a justification of various laws." 260 U.S., at 415, 43 S.Ct., at 160.

Many cases before and since Pennsylvania Coal have recognized that the nature of the State's action is critical in takings analysis. In Mugler v. Kansas, 123 U.S. 623, 8 S.Ct. 273, 31 L.Ed. 205 (1887), for example, a Kansas distiller who had built a brewery while it was legal to do so challenged a Kansas constitutional amendment which prohibited the manufacture and sale of intoxicating liquors. Although the Court recognized that the "buildings and machinery constituting these breweries are of little value" because of the Amendment, id., at 657, 8 S.Ct., at 294, Justice Harlan explained that a "prohibition simply upon the use of property for purposes that are declared, by valid legislation, to be injurious to the health, morals, or safety of the community, cannot, in any just sense, be deemed a taking or appropriation of property.... The power which the States have of prohibiting such use by individuals of their property as will be prejudicial to the health, the morals, or the safety of the public, is not--and, consistently with the existence and safety of organized society cannot be--burdened with the condition that the State must compensate such individual owners for pecuniary losses they may sustain, by reason of their not being permitted, by a noxious use of their property, to inflict injury upon the community."

* * *

The Court's hesitance to find a taking when the State merely restrains uses of property that are tantamount to public nuisances is consistent with the notion of "reciprocity of advantage" that Justice Holmes referred to in Pennsylvania Coal. Under our system of government, one of the State's primary ways of preserving the public weal is restricting the uses individuals can make of their property. While each of us is burdened somewhat by such restrictions, we, in turn, benefit greatly from the restrictions that are placed on others. See Penn Central Transportation Co. v. New York City, 438 U.S., at 144-150, 98 S.Ct., at 2669- 2672 (REHNQUIST, J., dissenting). * * *

In Agins v. Tiburon, we explained that the "determination that governmental action constitutes a taking, is, in essence, a determination that the public at large, rather than a single owner, must bear the burden of an exercise of state power in the public interest," and we recognized that this question "necessarily requires a weighing of private and public interests." 447 U.S., at 260-261, 100 S.Ct., at 2141. As the cases discussed above demonstrate, the public interest in preventing activities similar to public nuisances is a substantial one, which in many instances has not required compensation. The Subsidence Act, unlike the Kohler Act, plainly seeks to further such an interest. Nonetheless, we need not rest our decision on this factor alone, because petitioners have also failed to make a showing of diminution of value sufficient to satisfy the test set forth in Pennsylvania Coal and our other regulatory takings cases.

Diminution of Value and Investment-Backed Expectations

The second factor that distinguishes this case from Pennsylvania Coal is the finding in that case that the Kohler Act made mining of "certain coal" commercially impracticable. In this case, by contrast, petitioners have not shown any deprivation significant enough to satisfy the heavy burden placed upon one alleging a regulatory taking. For this reason, their takings claim must fail.

In addressing petitioners' claim we must not disregard the posture in which this case comes before us. The District Court granted summary judgment to respondents only on the facial challenge to the Subsidence Act. * * * Thus, the only question before this court is whether the mere enactment of the statutes and regulations constitutes a taking." * * *

The posture of the case is critical because we have recognized an important distinction between a claim that the mere enactment of a statute constitutes a taking and a claim that the particular impact of government action on a specific piece of property requires the payment of just compensation. This point is illustrated by our decision in Hodel v. Virginia Surface Mining & Reclamation Assn., Inc., 452 U.S. 264, 101 S.Ct. 2352, 69 L.Ed.2d 1 (1981), in which we rejected a preenforcement challenge to the constitutionality of the Surface Mining Control and Reclamation Act of 1977. * * * Petitioners thus face an uphill battle in making a facial attack on the Act as a taking.

The hill is made especially steep because petitioners have not claimed, at this stage, that the Act makes it commercially impracticable for them to continue mining their bituminous coal interests in western Pennsylvania. Indeed, petitioners have not even pointed to a single mine that can no longer be mined for profit. The only evidence available on the effect that the Subsidence Act has had on petitioners' mining operations comes from petitioners' answers to respondents' interrogatories. Petitioners described the effect that the Subsidence Act had from 1966-1982 on 13 mines that the various companies operate, and claimed that they have been required to leave a bit less than 27 million tons of coal in place to support ' 4 areas. The total coal in those 13 mines amounts to over 1.46 billion tons. Thus ' 4 requires them to leave less than 2% of their coal in place. But, as we have indicated, nowhere near all of the underground coal is extractable even aside from the Subsidence Act. The categories of coal that must be left for ' 4 purposes and other purposes are not necessarily distinct sets, and there is no information in the record as to how much coal is actually left in the ground solely because of ' 4. We do know, however, that petitioners have never claimed that their mining operations, or even any specific mines, have been unprofitable since the Subsidence Act was passed. Nor is there evidence that mining in any specific location affected by the 50% rule has been unprofitable.

Instead, petitioners have sought to narrowly define certain segments of their property and assert that, when so defined, the Subsidence Act denies them economically viable use. They advance two alternative ways of carving their property in order to reach this conclusion. First, they focus on the specific tons of coal that they must leave in the ground under the Subsidence Act, and argue that the Commonwealth has effectively appropriated this coal since it has no other useful purpose if not mined. Second, they contend that the Commonwealth has taken their separate legal interest in property--the "support estate."

Because our test for regulatory taking requires us to compare the value that has been taken from the property with the value that remains in the property, one of the critical questions is determining how to define the unit of property "whose value is to furnish the denominator of the fraction." Michelman, Property, Utility, and Fairness: Comments on the Ethical Foundations of "Just Compensation" Law, 80 Harv.L.Rev. 1165, 1192 (1967). In Penn Central the Court explained:

" 'Taking' jurisprudence does not divide a single parcel into discrete segments and attempt to determine whether rights in a particular segment have been entirely abrogated. In deciding whether a particular governmental action has effected a taking, this Court focuses rather both on the character of the action and on the nature of the interference with rights in the parcel as a whole --here the city tax block designated as the 'landmark site.' " 438 U.S., at 130-131, 98 S.Ct., at 2662.

* * *

The Coal in Place

The parties have stipulated that enforcement of the DER's 50% rule will require petitioners to leave approximately 27 million tons of coal in place. Because they own that coal but cannot mine it, they contend that Pennsylvania has appropriated it for the public purposes described in the Subsidence Act.

This argument fails for the reason explained in Penn Central and Andrus. The 27 million tons of coal do not constitute a separate segment of property for takings law purposes. Many zoning ordinances place limits on the property owner's right to make profitable use of some segments of his property. A requirement that a building occupy no more than a specified percentage of the lot on which it is located could be characterized as a taking of the vacant area as readily as the requirement that coal pillars be left in place. Similarly, under petitioners' theory one could always argue that a setback ordinance requiring that no structure be built within a certain distance from the property line constitutes a taking because the footage represents a distinct segment of property for takings law purposes. There is no basis for treating the less than 2% of petitioners' coal as a separate parcel of property.

[As the circuit court reasoned:]

When the coal that must remain beneath the ground is viewed in the context of any reasonable unit of petitioners' coal mining operations and financial-backed expectations, it is plain that petitioners have not come close to satisfying their burden of proving that they have been denied the economically viable use of that property. The record indicates that only about 75% of petitioners' underground coal can be profitably mined in any event, and there is no showing that petitioners' reasonable "investment-backed expectations" have been materially affected by the additional duty to retain the small percentage that must be used to support the structures protected by ' 4.

The Support Estate

Pennsylvania property law is apparently unique in regarding the support estate as a separate interest in land that can be conveyed apart from either the mineral estate or the surface estate. Petitioners therefore argue that even if comparable legislation in another State would not constitute a taking, the Subsidence Act has that consequence because it entirely destroys the value of their unique support estate. It is clear, however, that our takings jurisprudence forecloses reliance on such legalistic distinctions within a bundle of property rights. For example, in Penn Central, the Court rejected the argument that the "air rights" above the terminal constituted a separate segment of property for Takings Clause purposes. 438 U.S., at 130, 98 S.Ct., at 2662. Likewise, in Andrus v. Allard, we viewed the right to sell property as just one element of the owner's property interest. 444 U.S., at 65-66, 100 S.Ct., at 326-327. In neither case did the result turn on whether state law allowed the separate sale of the segment of property.

The Court of Appeals, which is more familiar with Pennsylvania law than we are, concluded that as a practical matter the support estate is always owned by either the owner of the surface or the owner of the minerals. It stated: "The support estate consists of the right to remove the strata of coal and earth that undergird the surface or to leave those layers intact to support the surface and prevent subsidence. These two uses cannot co-exist and, depending upon the purposes of the owner of the support estate, one use or the other must be chosen. If the owner is a mine operator, the support estate is used to exploit the mineral estate. When the right of support is held by the surface owner, its use is to support that surface and prevent subsidence. Thus, although Pennsylvania law does recognize the support estate as a 'separate' property interest, id., it cannot be used profitably by one who does not also possess either the mineral estate or the surface estate. See Montgomery, The Development of the Right of Subjacent Support and the 'Third Estate in Pennsylvania,' 25 Temple L.Q. 1, 21 (1951)." 771 F.2d, at 715-716.

Thus, in practical terms, the support estate has value only insofar as it protects or enhances the value of the estate with which it is associated. Its value is merely a part of the entire bundle of rights possessed by the owner of either the coal or the surface. Because petitioners retain the right to mine virtually all of the coal in their mineral estates, the burden the Act places on the support estate does not constitute a taking. Petitioners may continue to mine coal profitably even if they may not destroy or damage surface structures at will in the process.

But even if we were to accept petitioners' invitation to view the support estate as a distinct segment of property for "takings" purposes, they have not satisfied their heavy burden of sustaining a facial challenge to the Act. Petitioners have acquired or retained the support estate for a great deal of land, only part of which is protected under the Subsidence Act, which, of course, deals with subsidence in the immediate vicinity of certain structures, bodies of water, and cemeteries. See n. 6, supra. The record is devoid of any evidence on what percentage of the purchased support estates, either in the aggregate or with respect to any individual estate, has been affected by the Act. Under these circumstances, petitioners' facial attack under the Takings Clause must surely fail.

The judgment of the Court of Appeals is

Affirmed.

Chief Justice REHNQUIST, with whom Justice POWELL, Justice O'CONNOR, and Justice SCALIA join, dissenting.

* * *

The similarity of the public purpose of the present Act to that in Pennsylvania Coal does not resolve the question whether a taking has occurred; the existence of such a public purpose is merely a necessary prerequisite to the government's exercise of its taking power. See Hawaii Housing Authority v. Midkiff, 467 U.S. 229, 239-243, 245, 104 S.Ct. 2321, 2328- 2331, 2331-2332, 81 L.Ed.2d 186 (1984); Berman v. Parker, 348 U.S. 26, 32- 33, 75 S.Ct. 98, 102, 99 L.Ed. 27 (1954). The nature of these purposes may be relevant, for we have recognized that a taking does not occur where the government exercises its unquestioned authority to prevent a property owner from using his property to injure others without having to compensate the value of the forbidden use. See Goldblatt v. Hemp 369 U.S. 590, 82 S.Ct. 987, 8 L.Ed.2d 130 (1962); Hadacheck v. Sebastian, 239 U.S. 394, 36 S.Ct. 143, 60 L.Ed. 348 (1915); Mugler v. Kansas, 123 U.S. 623, 8 S.Ct. 273, 31 L.Ed. 205 (1887). See generally Penn Central Transportation Co. v. New York City, 438 U.S., at 144-146, 98 S.Ct., at 2669-2670 (REHNQUIST, J., dissenting). The Court today indicates that this "nuisance exception" alone might support its conclusion that no taking has occurred. Despite the Court's implication to the contrary, see ante, at 1242, and n. 15, the legitimacy of this purpose is a question of federal, rather than state, law, subject to independent scrutiny by this Court. This statute is not the type of regulation that our precedents have held to be within the "nuisance exception" to takings analysis.

The ease with which the Court moves from the recognition of public interests to the assertion that the activity here regulated is "akin to a public nuisance" suggests an exception far wider than recognized in our previous cases. "The nuisance exception to the taking guarantee," however, "is not coterminous with the police power itself," Penn Central Transportation, supra, at 145, 98 S.Ct., at 2669 (REHNQUIST, J., dissenting), but is a narrow exception allowing the government to prevent "a misuse or illegal use." Curtin v. Benson, 222 U.S. 78, 86, 32 S.Ct. 31, 32, 56 L.Ed. 102 (1911). It is not intended to allow "the prevention of a legal and essential use, an attribute of its ownership." Ibid.

The narrow nature of this exception is compelled by the concerns underlying the Fifth Amendment. Though, as the Court recognizes, ante, at 1245, the Fifth Amendment does not prevent actions that secure a "reciprocity of advantage," Pennsylvania Coal, supra, 260 U.S., at 415, 43 S.Ct., at 160, it is designed to prevent "the public from loading upon one individual more than his just share of the burdens of government, and says that when he surrenders to the public something more and different from that which is exacted from other members of the public, a full and just equivalent shall be returned to him." Monongahela Navigation Co. v. United States, 148 U.S. 312, 325, 13 S.Ct. 622, 625, 37 L.Ed. 463 (1893). See also Penn Central Transportation Co. v. New York City, supra, 438 U.S., at 123-125, 98 S.Ct., at 2658-2659; Armstrong v. 65 United States, 364 U.S. 40, 49, 80 S.Ct. 1563, 1569, 4 L.Ed.2d 1554 (1960). A broad exception to the operation of the Just Compensation Clause based on the exercise of multifaceted health, welfare, and safety regulations would surely allow government much greater authority than we have recognized to impose societal burdens on individual landowners, for nearly every action the government takes is intended to secure for the public an extra measure of "health, safety, and welfare."

Though suggesting that the purposes alone are sufficient to uphold the Act, the Court avoids reliance on the nuisance exception by finding that the Subsidence Act does not impair petitioners' investment-backed expectations or ability to profitably operate their businesses. This conclusion follows mainly from the Court's broad definition of the "relevant mass of property," ante, at 1248, which allows it to ascribe to the Subsidence Act a less pernicious effect on the interests of the property owner. The need to consider the effect of regulation on some identifiable segment of property makes all important the admittedly difficult task of defining the relevant parcel. See Penn Central Transportation Co. v. New York City, 438 U.S., at 149, n. 13, 98 S.Ct., at 2672, n. 13 (REHNQUIST, J., dissenting). For the reasons explained below, I do not believe that the Court's opinion adequately performs this task.

III

The Court's conclusion that the restriction on particular coal does not work a taking is primarily the result of its view that the 27 million tons of coal in the ground "do not constitute a separate segment of property for takings law purposes." This conclusion cannot be based on the view that the interests are too insignificant to warrant protection by the Fifth Amendment, for it is beyond cavil that government appropriation of "relatively small amounts of private property for its own use" requires just compensation. Instead, the Court's refusal to recognize the coal in the ground as a separate segment of property for takings purposes is based on the fact that the alleged taking is "regulatory," rather than a physical intrusion. On the facts of this case, I cannot see how the label placed on the government's action is relevant to consideration of its impact on property rights.

Our decisions establish that governmental action short of physical invasion may constitute a taking because such regulatory action might result in "as complete [a loss] as if the [government] had entered upon the surface of the land and taken exclusive possession of it." United States v. Causby, 328 U.S. 256, 261, 66 S.Ct. 1062, 1065, 90 L.Ed. 1206 (1946). Though the government's direct benefit may vary depending upon the nature of its action, the question is evaluated from the perspective of the property holder's loss rather than the government's gain. See ibid.; United States v. General Motors Corp., 323 U.S. 373, 378, 65 S.Ct. 357, 359, 89 L.Ed. 311 (1945); Boston Chamber of Commerce v. Boston, 217 U.S. 189, 195, 30 S.Ct. 459, 460, 54 L.Ed. 725 (1910). Our observation that "[a] 'taking' may more readily be found when the interference with property can be characterized as a physical invasion by government," Penn Central Transportation Co. v. New York City, supra, 438 U.S., at 124, 98 S.Ct., at 2659, was not intended to alter this perspective merely because the claimed taking is by regulation. Instead, we have recognized that regulations--unlike physical invasions--do not typically extinguish the "full bundle" of rights in a particular piece of property. In Andrus v. Allard, 444 U.S. 51, 66, 100 S.Ct. 318, 327, 62 L.Ed.2d 210 (1979), for example, we found it crucial that a prohibition on the sale of avian artifacts destroyed only "one 'strand' of the bundle" of property rights, "because the aggregate must be viewed in its entirety." This characteristic of regulations frequently makes unclear the breadth of their impact on identifiable segments of property, and has required that we evaluate the effects in light of the "several factors" enumerated in Penn Central Transportation Co.: "The economic impact of the regulation on the claimant, ... the extent to which the regulation has interfered with investment-backed expectations, [and] the character of the governmental action." 438 U.S., at 124, 98 S.Ct., at 2659.

No one, however, would find any need to employ these analytical tools where the government has physically taken an identifiable segment of property. Physical appropriation by the government leaves no doubt that it has in fact deprived the owner of all uses of the land. Similarly, there is no need for further analysis where the government by regulation extinguishes the whole bundle of rights in an identifiable segment of property, for the effect of this action on the holder of the property is indistinguishable from the effect of a physical taking. Thus, it is clear our decision in Andrus v. Allard, supra, would have been different if the Government had confiscated the avian artifacts. In my view, a different result would also follow if the Government simply prohibited every use of that property, for the owner would still have been "deprive[d] of all or most of his interest in the subject matter." United States v. General Motors Corp. supra, 323 U.S., at 378, 65 S.Ct., at 359.

In this case, enforcement of the Subsidence Act and its regulations will require petitioners to leave approximately 27 million tons of coal in place. There is no question that this coal is an identifiable and separable property interest. Unlike many property interests, the "bundle" of rights in this coal is sparse. " 'For practical purposes, the right to coal consists in the right to mine it.' " Pennsylvania Coal, 260 U.S., at 414, 43 S.Ct., at 159, quoting Commonwealth ex rel. Keater v. Clearview Coal Co., 256 Pa., at 331, 100 A., at 820. From the relevant perspective--that of the property owners--this interest has been destroyed every bit as much as if the government had proceeded to mine the coal for its own use. The regulation, then, does not merely inhibit one strand in the bundle, cf. Andrus v. Allard, supra, but instead destroys completely any interest in a segment of property. In these circumstances, I think it unnecessary to consider whether petitioners may operate individual mines or their overall mining operations profitably, for they have been denied all use of 27 million tons of coal. I would hold that ' 4 of the Subsidence Act works a taking of these property interests.

Petitioners also claim that the Subsidence Act effects a taking of their support estate. Under Pennsylvania law, the support estate, the surface estate, and the mineral estate are "three distinct estates in land which can be held in fee simple separate and distinct from each other...." Captline v. County of Allegheny, 74 Pa.Commw. 85, 91, 459 A.2d 1298, 1301 (1983), cert. denied, 466 U.S. 904, 104 S.Ct. 1679, 80 L.Ed.2d 154 (1984). In refusing to consider the effect of the Subsidence Act on this property interest alone, the Court dismisses this feature of Pennsylvania property law as simply a "legalistic distinctio[n] within a bundle of property rights." "Its value," the Court informs us, "is merely a part of the entire bundle of rights possessed by the owner of either the coal or the surface." Ante, at 1250. See also 771 F.2d 707, 716 (1985) ("To focus upon the support estate separately ... would serve little purpose"). This view of the support estate allows the Court to conclude that its destruction is merely the destruction of one "strand" in petitioners' bundle of property rights, not significant enough in the overall bundle to work a taking.

Contrary to the Court's approach today, we have evaluated takings claims by reference to the units of property defined by state law. In Ruckleshaus v. Monsanto, Co., for example, we determined that certain "health, safety, and environmental data" was "cognizable as a trade-secret property right under Missouri law," 467 U.S., at 1003, 104 S.Ct., at 2873, and proceeded to evaluate the effects of governmental action on this state-defined property right. Reliance on state law is necessitated by the fact that " '[p]roperty interests ... are not created by the Constitution. Rather, they are created and their dimensions are defined by existing rules or understandings that stem from an independent source such as state law.' " Webb's Fabulous Pharmacies, Inc. v. Beckwith, 449 U.S. 155, 161, 101 S.Ct. 446, 450, 66 L.Ed.2d 358 (1980), quoting Board of Regents v. Roth, 408 U.S. 564, 577, 92 S.Ct. 2701, 2709, 33 L.Ed.2d 548 (1972).