Opinion ID: 1281848
Heading Depth: 1
Heading Rank: 7

Heading: The Tailings Basin Dams

Text: The tailings basin design for Mile Post 7 contemplates between 22,000 and 23,000 lineal feet of dams to enclose an area of some 5 square miles. One will be among the 30 largest dams in the world. To minimize the fugitive dust which will emanate from the basin, it will be covered with 10 feet of water. After 30 years of operation it is anticipated that the basin will be filled with tailings and only a small area of open water will remain. The rest of the basin dams and dikes will, by that time, be covered with vegetation which will be a part of an on-going technique for reducing air pollution by preventing wind and water erosion in the basin and on the dams and dikes. The basin will, in part, be contained by bedrock ridges of the Lake Superior highlands. At the main area of the largest dam the base will be 1,500 feet thick and 190 feet high at its peak. The dam slope will be at an angle of 6 horizontal feet to each vertical foot. The design calls for a safety margin of 1.5, which is to say there are 50 percent more resisting forces than activating forces. The basin itself will contain eight splitter dikes, each of which is intended to be self-contained and will minimize the likelihood that more than a fraction of the basin's contents will be released in the event of a breach. The hearing officer found that coarse tailings which will be used in dam construction are suitable for that purpose; that at the site of the largest dam, 30 to 40 feet of clay will provide suitable foundation if the water is expelled and the clay consolidated; and that the bedrock underlying the basin will present no structural problems affecting dam stability. He expressed four principal concerns in addition to location: Foundation, design, construction material, and construction procedures. Nowhere, however, does the hearing officer specify any engineering problem which will increase the likelihood of dam failure beyond that which would face any such structure which is well located and well built. He does conclude that in the event of a catastrophe the damage to adjoining residences and to Lake Superior would be far greater at Mile Post 7 than at Mile Post 20, and consequently he concludes that prudence would dictate the choice of a safer site. DNR and PCA concede that if the dams are built according to design and if all unexpected contingencies are properly met the dams cannot fail. Both agencies share the hearing officer's misgivings with respect to Reserve's intention to perform according to design. Based on what they regard as Reserve's less than forthright behavior in the past, the agencies assert that the hearing officer was correct in preferring an alternative site such as Mile Post 20. [5] Under Minn.St. 116D.04, subd. 6, no permit will be granted where it is likely to cause impairment of natural resources so long as there is a feasible and prudent alternative. We are of the opinion that this statute has no application where the safety of the proposed structure is undisputed. In other words, if the design, construction, and maintenance of the dams make it unlikely that they will impair natural resources, there is no need to consider feasible and prudent alternatives. Nevertheless, we note in passing that there are substantial factors which militate against a dam's functioning more effectively at Mile Post 20 than one located at Mile Post 7. Mile Post 20 would require a structure some 53,000 feet in length compared to 23,000 feet at Mile Post 7. The terrain at Mile Post 20 is flatter than Mile Post 7, has fewer natural barriers, and the underlying soil is less impervious. The predicted uncollected seepage during its operation would be 750 gallons per minute compared to 180 gallons at Mile Post 7. Post-operation uncollected seepage is predicted at 10,000 gallons per minute at Mile Post 20 compared to 500 gallons at Mile Post 7. In the event of a major catastrophe at Mile Post 20, tailings and silt would be discharged into tributaries of both the Cloquet River and Lake Superior. None of the experts for any of the parties testified that the dam as designed would be unsafe. [6] We held in North Suburban Sewer Dist. v. Water Pollution Comm., 281 Minn. 524, 162 N.W.2d 249 (1968), that where the events which might lead to water pollution are contingencies remote and unlikely to occur, factors which counterbalance them prevail. The Federal court in Life of the Land v. Brinegar, 485 F.2d 460, 472 (9 Cir. 1973), ruling on a water pollution issue, held that there was no need to consider an alternative solution whose effect cannot be reasonably ascertained, and whose implementation is deemed remote and speculative, citing Natural Resources Defense Council, Inc. v. Morton, 148 U.S. App.D.C. 5, 458 F.2d 827, 834 (1972). Other courts have reached a similar result. Portland Cement Assn. v. Ruckelshaus, 158 U.S. App.D.C. 308, 486 F.2d 375 (1973); Carolina Environ. Study Group v. United States, 166 U.S.App.D.C. 416, 510 F.2d 796 (1975); No. Anna Env. Coalition v. U. S. Nuclear Reg. Comm., 174 U.S.App.D.C. 428, 533 F.2d 655 (1976). In the Carolinacase it was undisputed that, although the probability of a nuclear accident was remote, its consequences would be catastrophic. The court there held: There is a point at which the probability of an occurrence may be so low as to render it almost totally unworthy of consideration. Neither we, nor the A.E.C. on this record, would treat lightly the horrible consequences of a Class 9 accident. Recognition of the minimal probability of such an event is not equatable with non-recognition of its consequences. Carolina Environ. Study Group v. United States, 510 F.2d 799. The court was also treating with a license for constructing a nuclear power plant in North Anna, supra. Objections were based in part on the possibility that filling a reservoir might trigger an earthquake. The agency appeal board found that the creation of the lake did not threaten to reactivate a fault under it, and that the site was a stable one. In affirming, the Federal court noted that the Federal statute and regulations do not require a totally risk-free siting but only adequate protection to the health and safety of the public. No. Anna Env. Coalition v. U. S. Nuclear Reg. Comm., 533 F.2d 665. The court held that, although there was not an absolute guarantee that the fault would not be reactivated, [a]bsolute risk-free siting is similar to other absolute positions and arguments that have been rejected by the courts. Relating the Federal rule to Minnesota law, it is significant that none of the provisions in our environmental statutes establishes a standard that guarantees absolute safety. Minn.St. 116.01 refers to a reasonable degree of purity of water, air, and land resources. Minn.St. 116.06, subd. 3, in defining air pollution, refers to contamination which would interfere unreasonably with the enjoyment of life or property. Minn.St. 116B.02, subd. 5, in defining pollution, refers to any conduct which materially and adversely affects or is likely to affect the environment. Minn.St. 116D.04, subd. 6, forbids state action which significantly affects the quality of the environment. As we construe the hearing officer's conclusions, adopted by the administrative agency, he required that the design and construction of the dam eliminate the risk of dam failure. There was no substantial evidence to support a finding that the location of the dam at Mile Post 7 presented a significant threat to public health or safety, and no such finding was made. It is apparent from the findings and recommendations of the hearing officer that he lacked confidence in the candor, cooperation, and good faith of Reserve officials, and as we have noted, he questioned the likelihood of their building and maintaining the dam as designed. We have alluded to the Federal court's finding that Reserve was derelict in some of its dealings with that court. However, we are not prepared to assume that the company will risk the lives of innocent persons by casually disregarding its responsibility to construct a facility which will remain perpetually secure. The conditions imposed in issuing permits guarantee on-going monitoring and supervision by the state, and Reserve and its owners have assumed all risks and liabilities arising out of the operation of Mile Post 7. Under such circumstances, we hold that it was error to deny the permit at Mile Post 7 insofar as the agencies based their decision on a finding that, although a dam at Mile Post 7 would be safe, Mile Post 20 was a feasible and prudent alternative.